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.. SPDX-License-Identifier: GPL-2.0 |
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=================================================================== |
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The Definitive KVM (Kernel-based Virtual Machine) API Documentation |
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=================================================================== |
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1. General description |
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====================== |
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The kvm API is a set of ioctls that are issued to control various aspects |
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of a virtual machine. The ioctls belong to the following classes: |
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- System ioctls: These query and set global attributes which affect the |
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whole kvm subsystem. In addition a system ioctl is used to create |
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virtual machines. |
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- VM ioctls: These query and set attributes that affect an entire virtual |
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machine, for example memory layout. In addition a VM ioctl is used to |
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create virtual cpus (vcpus) and devices. |
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VM ioctls must be issued from the same process (address space) that was |
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used to create the VM. |
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- vcpu ioctls: These query and set attributes that control the operation |
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of a single virtual cpu. |
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vcpu ioctls should be issued from the same thread that was used to create |
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the vcpu, except for asynchronous vcpu ioctl that are marked as such in |
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the documentation. Otherwise, the first ioctl after switching threads |
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could see a performance impact. |
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- device ioctls: These query and set attributes that control the operation |
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of a single device. |
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device ioctls must be issued from the same process (address space) that |
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was used to create the VM. |
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2. File descriptors |
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=================== |
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The kvm API is centered around file descriptors. An initial |
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open("/dev/kvm") obtains a handle to the kvm subsystem; this handle |
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can be used to issue system ioctls. A KVM_CREATE_VM ioctl on this |
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handle will create a VM file descriptor which can be used to issue VM |
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ioctls. A KVM_CREATE_VCPU or KVM_CREATE_DEVICE ioctl on a VM fd will |
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create a virtual cpu or device and return a file descriptor pointing to |
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the new resource. Finally, ioctls on a vcpu or device fd can be used |
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to control the vcpu or device. For vcpus, this includes the important |
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task of actually running guest code. |
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In general file descriptors can be migrated among processes by means |
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of fork() and the SCM_RIGHTS facility of unix domain socket. These |
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kinds of tricks are explicitly not supported by kvm. While they will |
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not cause harm to the host, their actual behavior is not guaranteed by |
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the API. See "General description" for details on the ioctl usage |
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model that is supported by KVM. |
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It is important to note that although VM ioctls may only be issued from |
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the process that created the VM, a VM's lifecycle is associated with its |
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file descriptor, not its creator (process). In other words, the VM and |
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its resources, *including the associated address space*, are not freed |
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until the last reference to the VM's file descriptor has been released. |
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For example, if fork() is issued after ioctl(KVM_CREATE_VM), the VM will |
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not be freed until both the parent (original) process and its child have |
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put their references to the VM's file descriptor. |
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Because a VM's resources are not freed until the last reference to its |
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file descriptor is released, creating additional references to a VM |
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via fork(), dup(), etc... without careful consideration is strongly |
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discouraged and may have unwanted side effects, e.g. memory allocated |
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by and on behalf of the VM's process may not be freed/unaccounted when |
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the VM is shut down. |
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3. Extensions |
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============= |
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As of Linux 2.6.22, the KVM ABI has been stabilized: no backward |
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incompatible change are allowed. However, there is an extension |
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facility that allows backward-compatible extensions to the API to be |
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queried and used. |
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The extension mechanism is not based on the Linux version number. |
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Instead, kvm defines extension identifiers and a facility to query |
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whether a particular extension identifier is available. If it is, a |
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set of ioctls is available for application use. |
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4. API description |
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================== |
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This section describes ioctls that can be used to control kvm guests. |
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For each ioctl, the following information is provided along with a |
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description: |
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Capability: |
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which KVM extension provides this ioctl. Can be 'basic', |
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which means that is will be provided by any kernel that supports |
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API version 12 (see section 4.1), a KVM_CAP_xyz constant, which |
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means availability needs to be checked with KVM_CHECK_EXTENSION |
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(see section 4.4), or 'none' which means that while not all kernels |
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support this ioctl, there's no capability bit to check its |
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availability: for kernels that don't support the ioctl, |
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the ioctl returns -ENOTTY. |
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Architectures: |
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which instruction set architectures provide this ioctl. |
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x86 includes both i386 and x86_64. |
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Type: |
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system, vm, or vcpu. |
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Parameters: |
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what parameters are accepted by the ioctl. |
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Returns: |
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the return value. General error numbers (EBADF, ENOMEM, EINVAL) |
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are not detailed, but errors with specific meanings are. |
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4.1 KVM_GET_API_VERSION |
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----------------------- |
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:Capability: basic |
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:Architectures: all |
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:Type: system ioctl |
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:Parameters: none |
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:Returns: the constant KVM_API_VERSION (=12) |
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This identifies the API version as the stable kvm API. It is not |
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expected that this number will change. However, Linux 2.6.20 and |
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2.6.21 report earlier versions; these are not documented and not |
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supported. Applications should refuse to run if KVM_GET_API_VERSION |
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returns a value other than 12. If this check passes, all ioctls |
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described as 'basic' will be available. |
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4.2 KVM_CREATE_VM |
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----------------- |
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:Capability: basic |
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:Architectures: all |
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:Type: system ioctl |
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:Parameters: machine type identifier (KVM_VM_*) |
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:Returns: a VM fd that can be used to control the new virtual machine. |
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The new VM has no virtual cpus and no memory. |
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You probably want to use 0 as machine type. |
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In order to create user controlled virtual machines on S390, check |
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KVM_CAP_S390_UCONTROL and use the flag KVM_VM_S390_UCONTROL as |
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privileged user (CAP_SYS_ADMIN). |
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To use hardware assisted virtualization on MIPS (VZ ASE) rather than |
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the default trap & emulate implementation (which changes the virtual |
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memory layout to fit in user mode), check KVM_CAP_MIPS_VZ and use the |
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flag KVM_VM_MIPS_VZ. |
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On arm64, the physical address size for a VM (IPA Size limit) is limited |
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to 40bits by default. The limit can be configured if the host supports the |
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extension KVM_CAP_ARM_VM_IPA_SIZE. When supported, use |
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KVM_VM_TYPE_ARM_IPA_SIZE(IPA_Bits) to set the size in the machine type |
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identifier, where IPA_Bits is the maximum width of any physical |
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address used by the VM. The IPA_Bits is encoded in bits[7-0] of the |
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machine type identifier. |
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e.g, to configure a guest to use 48bit physical address size:: |
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vm_fd = ioctl(dev_fd, KVM_CREATE_VM, KVM_VM_TYPE_ARM_IPA_SIZE(48)); |
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The requested size (IPA_Bits) must be: |
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== ========================================================= |
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0 Implies default size, 40bits (for backward compatibility) |
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N Implies N bits, where N is a positive integer such that, |
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32 <= N <= Host_IPA_Limit |
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== ========================================================= |
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Host_IPA_Limit is the maximum possible value for IPA_Bits on the host and |
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is dependent on the CPU capability and the kernel configuration. The limit can |
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be retrieved using KVM_CAP_ARM_VM_IPA_SIZE of the KVM_CHECK_EXTENSION |
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ioctl() at run-time. |
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Creation of the VM will fail if the requested IPA size (whether it is |
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implicit or explicit) is unsupported on the host. |
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Please note that configuring the IPA size does not affect the capability |
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exposed by the guest CPUs in ID_AA64MMFR0_EL1[PARange]. It only affects |
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size of the address translated by the stage2 level (guest physical to |
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host physical address translations). |
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4.3 KVM_GET_MSR_INDEX_LIST, KVM_GET_MSR_FEATURE_INDEX_LIST |
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---------------------------------------------------------- |
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:Capability: basic, KVM_CAP_GET_MSR_FEATURES for KVM_GET_MSR_FEATURE_INDEX_LIST |
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:Architectures: x86 |
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:Type: system ioctl |
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:Parameters: struct kvm_msr_list (in/out) |
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:Returns: 0 on success; -1 on error |
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Errors: |
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====== ============================================================ |
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EFAULT the msr index list cannot be read from or written to |
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E2BIG the msr index list is too big to fit in the array specified by |
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the user. |
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====== ============================================================ |
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:: |
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struct kvm_msr_list { |
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__u32 nmsrs; /* number of msrs in entries */ |
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__u32 indices[0]; |
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}; |
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The user fills in the size of the indices array in nmsrs, and in return |
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kvm adjusts nmsrs to reflect the actual number of msrs and fills in the |
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indices array with their numbers. |
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KVM_GET_MSR_INDEX_LIST returns the guest msrs that are supported. The list |
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varies by kvm version and host processor, but does not change otherwise. |
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Note: if kvm indicates supports MCE (KVM_CAP_MCE), then the MCE bank MSRs are |
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not returned in the MSR list, as different vcpus can have a different number |
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of banks, as set via the KVM_X86_SETUP_MCE ioctl. |
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KVM_GET_MSR_FEATURE_INDEX_LIST returns the list of MSRs that can be passed |
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to the KVM_GET_MSRS system ioctl. This lets userspace probe host capabilities |
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and processor features that are exposed via MSRs (e.g., VMX capabilities). |
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This list also varies by kvm version and host processor, but does not change |
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otherwise. |
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4.4 KVM_CHECK_EXTENSION |
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----------------------- |
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:Capability: basic, KVM_CAP_CHECK_EXTENSION_VM for vm ioctl |
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:Architectures: all |
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:Type: system ioctl, vm ioctl |
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:Parameters: extension identifier (KVM_CAP_*) |
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:Returns: 0 if unsupported; 1 (or some other positive integer) if supported |
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The API allows the application to query about extensions to the core |
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kvm API. Userspace passes an extension identifier (an integer) and |
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receives an integer that describes the extension availability. |
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Generally 0 means no and 1 means yes, but some extensions may report |
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additional information in the integer return value. |
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Based on their initialization different VMs may have different capabilities. |
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It is thus encouraged to use the vm ioctl to query for capabilities (available |
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with KVM_CAP_CHECK_EXTENSION_VM on the vm fd) |
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4.5 KVM_GET_VCPU_MMAP_SIZE |
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-------------------------- |
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:Capability: basic |
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:Architectures: all |
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:Type: system ioctl |
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:Parameters: none |
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:Returns: size of vcpu mmap area, in bytes |
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The KVM_RUN ioctl (cf.) communicates with userspace via a shared |
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memory region. This ioctl returns the size of that region. See the |
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KVM_RUN documentation for details. |
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Besides the size of the KVM_RUN communication region, other areas of |
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the VCPU file descriptor can be mmap-ed, including: |
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- if KVM_CAP_COALESCED_MMIO is available, a page at |
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KVM_COALESCED_MMIO_PAGE_OFFSET * PAGE_SIZE; for historical reasons, |
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this page is included in the result of KVM_GET_VCPU_MMAP_SIZE. |
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KVM_CAP_COALESCED_MMIO is not documented yet. |
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- if KVM_CAP_DIRTY_LOG_RING is available, a number of pages at |
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KVM_DIRTY_LOG_PAGE_OFFSET * PAGE_SIZE. For more information on |
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KVM_CAP_DIRTY_LOG_RING, see section 8.3. |
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4.6 KVM_SET_MEMORY_REGION |
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------------------------- |
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:Capability: basic |
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:Architectures: all |
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:Type: vm ioctl |
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:Parameters: struct kvm_memory_region (in) |
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:Returns: 0 on success, -1 on error |
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This ioctl is obsolete and has been removed. |
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4.7 KVM_CREATE_VCPU |
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------------------- |
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:Capability: basic |
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:Architectures: all |
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:Type: vm ioctl |
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:Parameters: vcpu id (apic id on x86) |
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:Returns: vcpu fd on success, -1 on error |
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This API adds a vcpu to a virtual machine. No more than max_vcpus may be added. |
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The vcpu id is an integer in the range [0, max_vcpu_id). |
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The recommended max_vcpus value can be retrieved using the KVM_CAP_NR_VCPUS of |
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the KVM_CHECK_EXTENSION ioctl() at run-time. |
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The maximum possible value for max_vcpus can be retrieved using the |
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KVM_CAP_MAX_VCPUS of the KVM_CHECK_EXTENSION ioctl() at run-time. |
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If the KVM_CAP_NR_VCPUS does not exist, you should assume that max_vcpus is 4 |
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cpus max. |
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If the KVM_CAP_MAX_VCPUS does not exist, you should assume that max_vcpus is |
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same as the value returned from KVM_CAP_NR_VCPUS. |
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The maximum possible value for max_vcpu_id can be retrieved using the |
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KVM_CAP_MAX_VCPU_ID of the KVM_CHECK_EXTENSION ioctl() at run-time. |
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If the KVM_CAP_MAX_VCPU_ID does not exist, you should assume that max_vcpu_id |
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is the same as the value returned from KVM_CAP_MAX_VCPUS. |
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On powerpc using book3s_hv mode, the vcpus are mapped onto virtual |
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threads in one or more virtual CPU cores. (This is because the |
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hardware requires all the hardware threads in a CPU core to be in the |
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same partition.) The KVM_CAP_PPC_SMT capability indicates the number |
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of vcpus per virtual core (vcore). The vcore id is obtained by |
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dividing the vcpu id by the number of vcpus per vcore. The vcpus in a |
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given vcore will always be in the same physical core as each other |
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(though that might be a different physical core from time to time). |
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Userspace can control the threading (SMT) mode of the guest by its |
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allocation of vcpu ids. For example, if userspace wants |
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single-threaded guest vcpus, it should make all vcpu ids be a multiple |
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of the number of vcpus per vcore. |
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For virtual cpus that have been created with S390 user controlled virtual |
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machines, the resulting vcpu fd can be memory mapped at page offset |
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KVM_S390_SIE_PAGE_OFFSET in order to obtain a memory map of the virtual |
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cpu's hardware control block. |
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4.8 KVM_GET_DIRTY_LOG (vm ioctl) |
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-------------------------------- |
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:Capability: basic |
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:Architectures: all |
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:Type: vm ioctl |
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:Parameters: struct kvm_dirty_log (in/out) |
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:Returns: 0 on success, -1 on error |
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:: |
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/* for KVM_GET_DIRTY_LOG */ |
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struct kvm_dirty_log { |
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__u32 slot; |
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__u32 padding; |
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union { |
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void __user *dirty_bitmap; /* one bit per page */ |
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__u64 padding; |
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}; |
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}; |
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Given a memory slot, return a bitmap containing any pages dirtied |
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since the last call to this ioctl. Bit 0 is the first page in the |
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memory slot. Ensure the entire structure is cleared to avoid padding |
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issues. |
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If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of slot field specifies |
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the address space for which you want to return the dirty bitmap. See |
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KVM_SET_USER_MEMORY_REGION for details on the usage of slot field. |
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The bits in the dirty bitmap are cleared before the ioctl returns, unless |
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KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is enabled. For more information, |
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see the description of the capability. |
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4.9 KVM_SET_MEMORY_ALIAS |
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------------------------ |
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:Capability: basic |
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:Architectures: x86 |
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:Type: vm ioctl |
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:Parameters: struct kvm_memory_alias (in) |
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:Returns: 0 (success), -1 (error) |
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This ioctl is obsolete and has been removed. |
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4.10 KVM_RUN |
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------------ |
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:Capability: basic |
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:Architectures: all |
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:Type: vcpu ioctl |
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:Parameters: none |
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:Returns: 0 on success, -1 on error |
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Errors: |
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======= ============================================================== |
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EINTR an unmasked signal is pending |
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ENOEXEC the vcpu hasn't been initialized or the guest tried to execute |
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instructions from device memory (arm64) |
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ENOSYS data abort outside memslots with no syndrome info and |
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KVM_CAP_ARM_NISV_TO_USER not enabled (arm64) |
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EPERM SVE feature set but not finalized (arm64) |
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======= ============================================================== |
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This ioctl is used to run a guest virtual cpu. While there are no |
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explicit parameters, there is an implicit parameter block that can be |
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obtained by mmap()ing the vcpu fd at offset 0, with the size given by |
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KVM_GET_VCPU_MMAP_SIZE. The parameter block is formatted as a 'struct |
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kvm_run' (see below). |
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4.11 KVM_GET_REGS |
|
----------------- |
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:Capability: basic |
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:Architectures: all except ARM, arm64 |
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:Type: vcpu ioctl |
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:Parameters: struct kvm_regs (out) |
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:Returns: 0 on success, -1 on error |
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Reads the general purpose registers from the vcpu. |
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:: |
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/* x86 */ |
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struct kvm_regs { |
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/* out (KVM_GET_REGS) / in (KVM_SET_REGS) */ |
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__u64 rax, rbx, rcx, rdx; |
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__u64 rsi, rdi, rsp, rbp; |
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__u64 r8, r9, r10, r11; |
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__u64 r12, r13, r14, r15; |
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__u64 rip, rflags; |
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}; |
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/* mips */ |
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struct kvm_regs { |
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/* out (KVM_GET_REGS) / in (KVM_SET_REGS) */ |
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__u64 gpr[32]; |
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__u64 hi; |
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__u64 lo; |
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__u64 pc; |
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}; |
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4.12 KVM_SET_REGS |
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----------------- |
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:Capability: basic |
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:Architectures: all except ARM, arm64 |
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:Type: vcpu ioctl |
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:Parameters: struct kvm_regs (in) |
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:Returns: 0 on success, -1 on error |
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Writes the general purpose registers into the vcpu. |
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See KVM_GET_REGS for the data structure. |
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4.13 KVM_GET_SREGS |
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------------------ |
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:Capability: basic |
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:Architectures: x86, ppc |
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:Type: vcpu ioctl |
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:Parameters: struct kvm_sregs (out) |
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:Returns: 0 on success, -1 on error |
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Reads special registers from the vcpu. |
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:: |
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/* x86 */ |
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struct kvm_sregs { |
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struct kvm_segment cs, ds, es, fs, gs, ss; |
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struct kvm_segment tr, ldt; |
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struct kvm_dtable gdt, idt; |
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__u64 cr0, cr2, cr3, cr4, cr8; |
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__u64 efer; |
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__u64 apic_base; |
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__u64 interrupt_bitmap[(KVM_NR_INTERRUPTS + 63) / 64]; |
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}; |
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/* ppc -- see arch/powerpc/include/uapi/asm/kvm.h */ |
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interrupt_bitmap is a bitmap of pending external interrupts. At most |
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one bit may be set. This interrupt has been acknowledged by the APIC |
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but not yet injected into the cpu core. |
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4.14 KVM_SET_SREGS |
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------------------ |
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:Capability: basic |
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:Architectures: x86, ppc |
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:Type: vcpu ioctl |
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:Parameters: struct kvm_sregs (in) |
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:Returns: 0 on success, -1 on error |
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Writes special registers into the vcpu. See KVM_GET_SREGS for the |
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data structures. |
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4.15 KVM_TRANSLATE |
|
------------------ |
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:Capability: basic |
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:Architectures: x86 |
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:Type: vcpu ioctl |
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:Parameters: struct kvm_translation (in/out) |
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:Returns: 0 on success, -1 on error |
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Translates a virtual address according to the vcpu's current address |
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translation mode. |
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:: |
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struct kvm_translation { |
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/* in */ |
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__u64 linear_address; |
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/* out */ |
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__u64 physical_address; |
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__u8 valid; |
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__u8 writeable; |
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__u8 usermode; |
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__u8 pad[5]; |
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}; |
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4.16 KVM_INTERRUPT |
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------------------ |
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:Capability: basic |
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:Architectures: x86, ppc, mips |
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:Type: vcpu ioctl |
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:Parameters: struct kvm_interrupt (in) |
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:Returns: 0 on success, negative on failure. |
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Queues a hardware interrupt vector to be injected. |
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:: |
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/* for KVM_INTERRUPT */ |
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struct kvm_interrupt { |
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/* in */ |
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__u32 irq; |
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}; |
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X86: |
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^^^^ |
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:Returns: |
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========= =================================== |
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0 on success, |
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-EEXIST if an interrupt is already enqueued |
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-EINVAL the irq number is invalid |
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-ENXIO if the PIC is in the kernel |
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-EFAULT if the pointer is invalid |
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========= =================================== |
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|
|
Note 'irq' is an interrupt vector, not an interrupt pin or line. This |
|
ioctl is useful if the in-kernel PIC is not used. |
|
|
|
PPC: |
|
^^^^ |
|
|
|
Queues an external interrupt to be injected. This ioctl is overleaded |
|
with 3 different irq values: |
|
|
|
a) KVM_INTERRUPT_SET |
|
|
|
This injects an edge type external interrupt into the guest once it's ready |
|
to receive interrupts. When injected, the interrupt is done. |
|
|
|
b) KVM_INTERRUPT_UNSET |
|
|
|
This unsets any pending interrupt. |
|
|
|
Only available with KVM_CAP_PPC_UNSET_IRQ. |
|
|
|
c) KVM_INTERRUPT_SET_LEVEL |
|
|
|
This injects a level type external interrupt into the guest context. The |
|
interrupt stays pending until a specific ioctl with KVM_INTERRUPT_UNSET |
|
is triggered. |
|
|
|
Only available with KVM_CAP_PPC_IRQ_LEVEL. |
|
|
|
Note that any value for 'irq' other than the ones stated above is invalid |
|
and incurs unexpected behavior. |
|
|
|
This is an asynchronous vcpu ioctl and can be invoked from any thread. |
|
|
|
MIPS: |
|
^^^^^ |
|
|
|
Queues an external interrupt to be injected into the virtual CPU. A negative |
|
interrupt number dequeues the interrupt. |
|
|
|
This is an asynchronous vcpu ioctl and can be invoked from any thread. |
|
|
|
|
|
4.17 KVM_DEBUG_GUEST |
|
-------------------- |
|
|
|
:Capability: basic |
|
:Architectures: none |
|
:Type: vcpu ioctl |
|
:Parameters: none) |
|
:Returns: -1 on error |
|
|
|
Support for this has been removed. Use KVM_SET_GUEST_DEBUG instead. |
|
|
|
|
|
4.18 KVM_GET_MSRS |
|
----------------- |
|
|
|
:Capability: basic (vcpu), KVM_CAP_GET_MSR_FEATURES (system) |
|
:Architectures: x86 |
|
:Type: system ioctl, vcpu ioctl |
|
:Parameters: struct kvm_msrs (in/out) |
|
:Returns: number of msrs successfully returned; |
|
-1 on error |
|
|
|
When used as a system ioctl: |
|
Reads the values of MSR-based features that are available for the VM. This |
|
is similar to KVM_GET_SUPPORTED_CPUID, but it returns MSR indices and values. |
|
The list of msr-based features can be obtained using KVM_GET_MSR_FEATURE_INDEX_LIST |
|
in a system ioctl. |
|
|
|
When used as a vcpu ioctl: |
|
Reads model-specific registers from the vcpu. Supported msr indices can |
|
be obtained using KVM_GET_MSR_INDEX_LIST in a system ioctl. |
|
|
|
:: |
|
|
|
struct kvm_msrs { |
|
__u32 nmsrs; /* number of msrs in entries */ |
|
__u32 pad; |
|
|
|
struct kvm_msr_entry entries[0]; |
|
}; |
|
|
|
struct kvm_msr_entry { |
|
__u32 index; |
|
__u32 reserved; |
|
__u64 data; |
|
}; |
|
|
|
Application code should set the 'nmsrs' member (which indicates the |
|
size of the entries array) and the 'index' member of each array entry. |
|
kvm will fill in the 'data' member. |
|
|
|
|
|
4.19 KVM_SET_MSRS |
|
----------------- |
|
|
|
:Capability: basic |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_msrs (in) |
|
:Returns: number of msrs successfully set (see below), -1 on error |
|
|
|
Writes model-specific registers to the vcpu. See KVM_GET_MSRS for the |
|
data structures. |
|
|
|
Application code should set the 'nmsrs' member (which indicates the |
|
size of the entries array), and the 'index' and 'data' members of each |
|
array entry. |
|
|
|
It tries to set the MSRs in array entries[] one by one. If setting an MSR |
|
fails, e.g., due to setting reserved bits, the MSR isn't supported/emulated |
|
by KVM, etc..., it stops processing the MSR list and returns the number of |
|
MSRs that have been set successfully. |
|
|
|
|
|
4.20 KVM_SET_CPUID |
|
------------------ |
|
|
|
:Capability: basic |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_cpuid (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Defines the vcpu responses to the cpuid instruction. Applications |
|
should use the KVM_SET_CPUID2 ioctl if available. |
|
|
|
Caveat emptor: |
|
- If this IOCTL fails, KVM gives no guarantees that previous valid CPUID |
|
configuration (if there is) is not corrupted. Userspace can get a copy |
|
of the resulting CPUID configuration through KVM_GET_CPUID2 in case. |
|
- Using KVM_SET_CPUID{,2} after KVM_RUN, i.e. changing the guest vCPU model |
|
after running the guest, may cause guest instability. |
|
- Using heterogeneous CPUID configurations, modulo APIC IDs, topology, etc... |
|
may cause guest instability. |
|
|
|
:: |
|
|
|
struct kvm_cpuid_entry { |
|
__u32 function; |
|
__u32 eax; |
|
__u32 ebx; |
|
__u32 ecx; |
|
__u32 edx; |
|
__u32 padding; |
|
}; |
|
|
|
/* for KVM_SET_CPUID */ |
|
struct kvm_cpuid { |
|
__u32 nent; |
|
__u32 padding; |
|
struct kvm_cpuid_entry entries[0]; |
|
}; |
|
|
|
|
|
4.21 KVM_SET_SIGNAL_MASK |
|
------------------------ |
|
|
|
:Capability: basic |
|
:Architectures: all |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_signal_mask (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Defines which signals are blocked during execution of KVM_RUN. This |
|
signal mask temporarily overrides the threads signal mask. Any |
|
unblocked signal received (except SIGKILL and SIGSTOP, which retain |
|
their traditional behaviour) will cause KVM_RUN to return with -EINTR. |
|
|
|
Note the signal will only be delivered if not blocked by the original |
|
signal mask. |
|
|
|
:: |
|
|
|
/* for KVM_SET_SIGNAL_MASK */ |
|
struct kvm_signal_mask { |
|
__u32 len; |
|
__u8 sigset[0]; |
|
}; |
|
|
|
|
|
4.22 KVM_GET_FPU |
|
---------------- |
|
|
|
:Capability: basic |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_fpu (out) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Reads the floating point state from the vcpu. |
|
|
|
:: |
|
|
|
/* for KVM_GET_FPU and KVM_SET_FPU */ |
|
struct kvm_fpu { |
|
__u8 fpr[8][16]; |
|
__u16 fcw; |
|
__u16 fsw; |
|
__u8 ftwx; /* in fxsave format */ |
|
__u8 pad1; |
|
__u16 last_opcode; |
|
__u64 last_ip; |
|
__u64 last_dp; |
|
__u8 xmm[16][16]; |
|
__u32 mxcsr; |
|
__u32 pad2; |
|
}; |
|
|
|
|
|
4.23 KVM_SET_FPU |
|
---------------- |
|
|
|
:Capability: basic |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_fpu (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Writes the floating point state to the vcpu. |
|
|
|
:: |
|
|
|
/* for KVM_GET_FPU and KVM_SET_FPU */ |
|
struct kvm_fpu { |
|
__u8 fpr[8][16]; |
|
__u16 fcw; |
|
__u16 fsw; |
|
__u8 ftwx; /* in fxsave format */ |
|
__u8 pad1; |
|
__u16 last_opcode; |
|
__u64 last_ip; |
|
__u64 last_dp; |
|
__u8 xmm[16][16]; |
|
__u32 mxcsr; |
|
__u32 pad2; |
|
}; |
|
|
|
|
|
4.24 KVM_CREATE_IRQCHIP |
|
----------------------- |
|
|
|
:Capability: KVM_CAP_IRQCHIP, KVM_CAP_S390_IRQCHIP (s390) |
|
:Architectures: x86, ARM, arm64, s390 |
|
:Type: vm ioctl |
|
:Parameters: none |
|
:Returns: 0 on success, -1 on error |
|
|
|
Creates an interrupt controller model in the kernel. |
|
On x86, creates a virtual ioapic, a virtual PIC (two PICs, nested), and sets up |
|
future vcpus to have a local APIC. IRQ routing for GSIs 0-15 is set to both |
|
PIC and IOAPIC; GSI 16-23 only go to the IOAPIC. |
|
On ARM/arm64, a GICv2 is created. Any other GIC versions require the usage of |
|
KVM_CREATE_DEVICE, which also supports creating a GICv2. Using |
|
KVM_CREATE_DEVICE is preferred over KVM_CREATE_IRQCHIP for GICv2. |
|
On s390, a dummy irq routing table is created. |
|
|
|
Note that on s390 the KVM_CAP_S390_IRQCHIP vm capability needs to be enabled |
|
before KVM_CREATE_IRQCHIP can be used. |
|
|
|
|
|
4.25 KVM_IRQ_LINE |
|
----------------- |
|
|
|
:Capability: KVM_CAP_IRQCHIP |
|
:Architectures: x86, arm, arm64 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_irq_level |
|
:Returns: 0 on success, -1 on error |
|
|
|
Sets the level of a GSI input to the interrupt controller model in the kernel. |
|
On some architectures it is required that an interrupt controller model has |
|
been previously created with KVM_CREATE_IRQCHIP. Note that edge-triggered |
|
interrupts require the level to be set to 1 and then back to 0. |
|
|
|
On real hardware, interrupt pins can be active-low or active-high. This |
|
does not matter for the level field of struct kvm_irq_level: 1 always |
|
means active (asserted), 0 means inactive (deasserted). |
|
|
|
x86 allows the operating system to program the interrupt polarity |
|
(active-low/active-high) for level-triggered interrupts, and KVM used |
|
to consider the polarity. However, due to bitrot in the handling of |
|
active-low interrupts, the above convention is now valid on x86 too. |
|
This is signaled by KVM_CAP_X86_IOAPIC_POLARITY_IGNORED. Userspace |
|
should not present interrupts to the guest as active-low unless this |
|
capability is present (or unless it is not using the in-kernel irqchip, |
|
of course). |
|
|
|
|
|
ARM/arm64 can signal an interrupt either at the CPU level, or at the |
|
in-kernel irqchip (GIC), and for in-kernel irqchip can tell the GIC to |
|
use PPIs designated for specific cpus. The irq field is interpreted |
|
like this:: |
|
|
|
bits: | 31 ... 28 | 27 ... 24 | 23 ... 16 | 15 ... 0 | |
|
field: | vcpu2_index | irq_type | vcpu_index | irq_id | |
|
|
|
The irq_type field has the following values: |
|
|
|
- irq_type[0]: |
|
out-of-kernel GIC: irq_id 0 is IRQ, irq_id 1 is FIQ |
|
- irq_type[1]: |
|
in-kernel GIC: SPI, irq_id between 32 and 1019 (incl.) |
|
(the vcpu_index field is ignored) |
|
- irq_type[2]: |
|
in-kernel GIC: PPI, irq_id between 16 and 31 (incl.) |
|
|
|
(The irq_id field thus corresponds nicely to the IRQ ID in the ARM GIC specs) |
|
|
|
In both cases, level is used to assert/deassert the line. |
|
|
|
When KVM_CAP_ARM_IRQ_LINE_LAYOUT_2 is supported, the target vcpu is |
|
identified as (256 * vcpu2_index + vcpu_index). Otherwise, vcpu2_index |
|
must be zero. |
|
|
|
Note that on arm/arm64, the KVM_CAP_IRQCHIP capability only conditions |
|
injection of interrupts for the in-kernel irqchip. KVM_IRQ_LINE can always |
|
be used for a userspace interrupt controller. |
|
|
|
:: |
|
|
|
struct kvm_irq_level { |
|
union { |
|
__u32 irq; /* GSI */ |
|
__s32 status; /* not used for KVM_IRQ_LEVEL */ |
|
}; |
|
__u32 level; /* 0 or 1 */ |
|
}; |
|
|
|
|
|
4.26 KVM_GET_IRQCHIP |
|
-------------------- |
|
|
|
:Capability: KVM_CAP_IRQCHIP |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_irqchip (in/out) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Reads the state of a kernel interrupt controller created with |
|
KVM_CREATE_IRQCHIP into a buffer provided by the caller. |
|
|
|
:: |
|
|
|
struct kvm_irqchip { |
|
__u32 chip_id; /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */ |
|
__u32 pad; |
|
union { |
|
char dummy[512]; /* reserving space */ |
|
struct kvm_pic_state pic; |
|
struct kvm_ioapic_state ioapic; |
|
} chip; |
|
}; |
|
|
|
|
|
4.27 KVM_SET_IRQCHIP |
|
-------------------- |
|
|
|
:Capability: KVM_CAP_IRQCHIP |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_irqchip (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Sets the state of a kernel interrupt controller created with |
|
KVM_CREATE_IRQCHIP from a buffer provided by the caller. |
|
|
|
:: |
|
|
|
struct kvm_irqchip { |
|
__u32 chip_id; /* 0 = PIC1, 1 = PIC2, 2 = IOAPIC */ |
|
__u32 pad; |
|
union { |
|
char dummy[512]; /* reserving space */ |
|
struct kvm_pic_state pic; |
|
struct kvm_ioapic_state ioapic; |
|
} chip; |
|
}; |
|
|
|
|
|
4.28 KVM_XEN_HVM_CONFIG |
|
----------------------- |
|
|
|
:Capability: KVM_CAP_XEN_HVM |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_xen_hvm_config (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Sets the MSR that the Xen HVM guest uses to initialize its hypercall |
|
page, and provides the starting address and size of the hypercall |
|
blobs in userspace. When the guest writes the MSR, kvm copies one |
|
page of a blob (32- or 64-bit, depending on the vcpu mode) to guest |
|
memory. |
|
|
|
:: |
|
|
|
struct kvm_xen_hvm_config { |
|
__u32 flags; |
|
__u32 msr; |
|
__u64 blob_addr_32; |
|
__u64 blob_addr_64; |
|
__u8 blob_size_32; |
|
__u8 blob_size_64; |
|
__u8 pad2[30]; |
|
}; |
|
|
|
If the KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL flag is returned from the |
|
KVM_CAP_XEN_HVM check, it may be set in the flags field of this ioctl. |
|
This requests KVM to generate the contents of the hypercall page |
|
automatically; hypercalls will be intercepted and passed to userspace |
|
through KVM_EXIT_XEN. In this case, all of the blob size and address |
|
fields must be zero. |
|
|
|
No other flags are currently valid in the struct kvm_xen_hvm_config. |
|
|
|
4.29 KVM_GET_CLOCK |
|
------------------ |
|
|
|
:Capability: KVM_CAP_ADJUST_CLOCK |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_clock_data (out) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Gets the current timestamp of kvmclock as seen by the current guest. In |
|
conjunction with KVM_SET_CLOCK, it is used to ensure monotonicity on scenarios |
|
such as migration. |
|
|
|
When KVM_CAP_ADJUST_CLOCK is passed to KVM_CHECK_EXTENSION, it returns the |
|
set of bits that KVM can return in struct kvm_clock_data's flag member. |
|
|
|
The only flag defined now is KVM_CLOCK_TSC_STABLE. If set, the returned |
|
value is the exact kvmclock value seen by all VCPUs at the instant |
|
when KVM_GET_CLOCK was called. If clear, the returned value is simply |
|
CLOCK_MONOTONIC plus a constant offset; the offset can be modified |
|
with KVM_SET_CLOCK. KVM will try to make all VCPUs follow this clock, |
|
but the exact value read by each VCPU could differ, because the host |
|
TSC is not stable. |
|
|
|
:: |
|
|
|
struct kvm_clock_data { |
|
__u64 clock; /* kvmclock current value */ |
|
__u32 flags; |
|
__u32 pad[9]; |
|
}; |
|
|
|
|
|
4.30 KVM_SET_CLOCK |
|
------------------ |
|
|
|
:Capability: KVM_CAP_ADJUST_CLOCK |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_clock_data (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Sets the current timestamp of kvmclock to the value specified in its parameter. |
|
In conjunction with KVM_GET_CLOCK, it is used to ensure monotonicity on scenarios |
|
such as migration. |
|
|
|
:: |
|
|
|
struct kvm_clock_data { |
|
__u64 clock; /* kvmclock current value */ |
|
__u32 flags; |
|
__u32 pad[9]; |
|
}; |
|
|
|
|
|
4.31 KVM_GET_VCPU_EVENTS |
|
------------------------ |
|
|
|
:Capability: KVM_CAP_VCPU_EVENTS |
|
:Extended by: KVM_CAP_INTR_SHADOW |
|
:Architectures: x86, arm, arm64 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_vcpu_event (out) |
|
:Returns: 0 on success, -1 on error |
|
|
|
X86: |
|
^^^^ |
|
|
|
Gets currently pending exceptions, interrupts, and NMIs as well as related |
|
states of the vcpu. |
|
|
|
:: |
|
|
|
struct kvm_vcpu_events { |
|
struct { |
|
__u8 injected; |
|
__u8 nr; |
|
__u8 has_error_code; |
|
__u8 pending; |
|
__u32 error_code; |
|
} exception; |
|
struct { |
|
__u8 injected; |
|
__u8 nr; |
|
__u8 soft; |
|
__u8 shadow; |
|
} interrupt; |
|
struct { |
|
__u8 injected; |
|
__u8 pending; |
|
__u8 masked; |
|
__u8 pad; |
|
} nmi; |
|
__u32 sipi_vector; |
|
__u32 flags; |
|
struct { |
|
__u8 smm; |
|
__u8 pending; |
|
__u8 smm_inside_nmi; |
|
__u8 latched_init; |
|
} smi; |
|
__u8 reserved[27]; |
|
__u8 exception_has_payload; |
|
__u64 exception_payload; |
|
}; |
|
|
|
The following bits are defined in the flags field: |
|
|
|
- KVM_VCPUEVENT_VALID_SHADOW may be set to signal that |
|
interrupt.shadow contains a valid state. |
|
|
|
- KVM_VCPUEVENT_VALID_SMM may be set to signal that smi contains a |
|
valid state. |
|
|
|
- KVM_VCPUEVENT_VALID_PAYLOAD may be set to signal that the |
|
exception_has_payload, exception_payload, and exception.pending |
|
fields contain a valid state. This bit will be set whenever |
|
KVM_CAP_EXCEPTION_PAYLOAD is enabled. |
|
|
|
ARM/ARM64: |
|
^^^^^^^^^^ |
|
|
|
If the guest accesses a device that is being emulated by the host kernel in |
|
such a way that a real device would generate a physical SError, KVM may make |
|
a virtual SError pending for that VCPU. This system error interrupt remains |
|
pending until the guest takes the exception by unmasking PSTATE.A. |
|
|
|
Running the VCPU may cause it to take a pending SError, or make an access that |
|
causes an SError to become pending. The event's description is only valid while |
|
the VPCU is not running. |
|
|
|
This API provides a way to read and write the pending 'event' state that is not |
|
visible to the guest. To save, restore or migrate a VCPU the struct representing |
|
the state can be read then written using this GET/SET API, along with the other |
|
guest-visible registers. It is not possible to 'cancel' an SError that has been |
|
made pending. |
|
|
|
A device being emulated in user-space may also wish to generate an SError. To do |
|
this the events structure can be populated by user-space. The current state |
|
should be read first, to ensure no existing SError is pending. If an existing |
|
SError is pending, the architecture's 'Multiple SError interrupts' rules should |
|
be followed. (2.5.3 of DDI0587.a "ARM Reliability, Availability, and |
|
Serviceability (RAS) Specification"). |
|
|
|
SError exceptions always have an ESR value. Some CPUs have the ability to |
|
specify what the virtual SError's ESR value should be. These systems will |
|
advertise KVM_CAP_ARM_INJECT_SERROR_ESR. In this case exception.has_esr will |
|
always have a non-zero value when read, and the agent making an SError pending |
|
should specify the ISS field in the lower 24 bits of exception.serror_esr. If |
|
the system supports KVM_CAP_ARM_INJECT_SERROR_ESR, but user-space sets the events |
|
with exception.has_esr as zero, KVM will choose an ESR. |
|
|
|
Specifying exception.has_esr on a system that does not support it will return |
|
-EINVAL. Setting anything other than the lower 24bits of exception.serror_esr |
|
will return -EINVAL. |
|
|
|
It is not possible to read back a pending external abort (injected via |
|
KVM_SET_VCPU_EVENTS or otherwise) because such an exception is always delivered |
|
directly to the virtual CPU). |
|
|
|
:: |
|
|
|
struct kvm_vcpu_events { |
|
struct { |
|
__u8 serror_pending; |
|
__u8 serror_has_esr; |
|
__u8 ext_dabt_pending; |
|
/* Align it to 8 bytes */ |
|
__u8 pad[5]; |
|
__u64 serror_esr; |
|
} exception; |
|
__u32 reserved[12]; |
|
}; |
|
|
|
4.32 KVM_SET_VCPU_EVENTS |
|
------------------------ |
|
|
|
:Capability: KVM_CAP_VCPU_EVENTS |
|
:Extended by: KVM_CAP_INTR_SHADOW |
|
:Architectures: x86, arm, arm64 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_vcpu_event (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
X86: |
|
^^^^ |
|
|
|
Set pending exceptions, interrupts, and NMIs as well as related states of the |
|
vcpu. |
|
|
|
See KVM_GET_VCPU_EVENTS for the data structure. |
|
|
|
Fields that may be modified asynchronously by running VCPUs can be excluded |
|
from the update. These fields are nmi.pending, sipi_vector, smi.smm, |
|
smi.pending. Keep the corresponding bits in the flags field cleared to |
|
suppress overwriting the current in-kernel state. The bits are: |
|
|
|
=============================== ================================== |
|
KVM_VCPUEVENT_VALID_NMI_PENDING transfer nmi.pending to the kernel |
|
KVM_VCPUEVENT_VALID_SIPI_VECTOR transfer sipi_vector |
|
KVM_VCPUEVENT_VALID_SMM transfer the smi sub-struct. |
|
=============================== ================================== |
|
|
|
If KVM_CAP_INTR_SHADOW is available, KVM_VCPUEVENT_VALID_SHADOW can be set in |
|
the flags field to signal that interrupt.shadow contains a valid state and |
|
shall be written into the VCPU. |
|
|
|
KVM_VCPUEVENT_VALID_SMM can only be set if KVM_CAP_X86_SMM is available. |
|
|
|
If KVM_CAP_EXCEPTION_PAYLOAD is enabled, KVM_VCPUEVENT_VALID_PAYLOAD |
|
can be set in the flags field to signal that the |
|
exception_has_payload, exception_payload, and exception.pending fields |
|
contain a valid state and shall be written into the VCPU. |
|
|
|
ARM/ARM64: |
|
^^^^^^^^^^ |
|
|
|
User space may need to inject several types of events to the guest. |
|
|
|
Set the pending SError exception state for this VCPU. It is not possible to |
|
'cancel' an Serror that has been made pending. |
|
|
|
If the guest performed an access to I/O memory which could not be handled by |
|
userspace, for example because of missing instruction syndrome decode |
|
information or because there is no device mapped at the accessed IPA, then |
|
userspace can ask the kernel to inject an external abort using the address |
|
from the exiting fault on the VCPU. It is a programming error to set |
|
ext_dabt_pending after an exit which was not either KVM_EXIT_MMIO or |
|
KVM_EXIT_ARM_NISV. This feature is only available if the system supports |
|
KVM_CAP_ARM_INJECT_EXT_DABT. This is a helper which provides commonality in |
|
how userspace reports accesses for the above cases to guests, across different |
|
userspace implementations. Nevertheless, userspace can still emulate all Arm |
|
exceptions by manipulating individual registers using the KVM_SET_ONE_REG API. |
|
|
|
See KVM_GET_VCPU_EVENTS for the data structure. |
|
|
|
|
|
4.33 KVM_GET_DEBUGREGS |
|
---------------------- |
|
|
|
:Capability: KVM_CAP_DEBUGREGS |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_debugregs (out) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Reads debug registers from the vcpu. |
|
|
|
:: |
|
|
|
struct kvm_debugregs { |
|
__u64 db[4]; |
|
__u64 dr6; |
|
__u64 dr7; |
|
__u64 flags; |
|
__u64 reserved[9]; |
|
}; |
|
|
|
|
|
4.34 KVM_SET_DEBUGREGS |
|
---------------------- |
|
|
|
:Capability: KVM_CAP_DEBUGREGS |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_debugregs (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Writes debug registers into the vcpu. |
|
|
|
See KVM_GET_DEBUGREGS for the data structure. The flags field is unused |
|
yet and must be cleared on entry. |
|
|
|
|
|
4.35 KVM_SET_USER_MEMORY_REGION |
|
------------------------------- |
|
|
|
:Capability: KVM_CAP_USER_MEMORY |
|
:Architectures: all |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_userspace_memory_region (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
:: |
|
|
|
struct kvm_userspace_memory_region { |
|
__u32 slot; |
|
__u32 flags; |
|
__u64 guest_phys_addr; |
|
__u64 memory_size; /* bytes */ |
|
__u64 userspace_addr; /* start of the userspace allocated memory */ |
|
}; |
|
|
|
/* for kvm_memory_region::flags */ |
|
#define KVM_MEM_LOG_DIRTY_PAGES (1UL << 0) |
|
#define KVM_MEM_READONLY (1UL << 1) |
|
|
|
This ioctl allows the user to create, modify or delete a guest physical |
|
memory slot. Bits 0-15 of "slot" specify the slot id and this value |
|
should be less than the maximum number of user memory slots supported per |
|
VM. The maximum allowed slots can be queried using KVM_CAP_NR_MEMSLOTS. |
|
Slots may not overlap in guest physical address space. |
|
|
|
If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of "slot" |
|
specifies the address space which is being modified. They must be |
|
less than the value that KVM_CHECK_EXTENSION returns for the |
|
KVM_CAP_MULTI_ADDRESS_SPACE capability. Slots in separate address spaces |
|
are unrelated; the restriction on overlapping slots only applies within |
|
each address space. |
|
|
|
Deleting a slot is done by passing zero for memory_size. When changing |
|
an existing slot, it may be moved in the guest physical memory space, |
|
or its flags may be modified, but it may not be resized. |
|
|
|
Memory for the region is taken starting at the address denoted by the |
|
field userspace_addr, which must point at user addressable memory for |
|
the entire memory slot size. Any object may back this memory, including |
|
anonymous memory, ordinary files, and hugetlbfs. |
|
|
|
On architectures that support a form of address tagging, userspace_addr must |
|
be an untagged address. |
|
|
|
It is recommended that the lower 21 bits of guest_phys_addr and userspace_addr |
|
be identical. This allows large pages in the guest to be backed by large |
|
pages in the host. |
|
|
|
The flags field supports two flags: KVM_MEM_LOG_DIRTY_PAGES and |
|
KVM_MEM_READONLY. The former can be set to instruct KVM to keep track of |
|
writes to memory within the slot. See KVM_GET_DIRTY_LOG ioctl to know how to |
|
use it. The latter can be set, if KVM_CAP_READONLY_MEM capability allows it, |
|
to make a new slot read-only. In this case, writes to this memory will be |
|
posted to userspace as KVM_EXIT_MMIO exits. |
|
|
|
When the KVM_CAP_SYNC_MMU capability is available, changes in the backing of |
|
the memory region are automatically reflected into the guest. For example, an |
|
mmap() that affects the region will be made visible immediately. Another |
|
example is madvise(MADV_DROP). |
|
|
|
It is recommended to use this API instead of the KVM_SET_MEMORY_REGION ioctl. |
|
The KVM_SET_MEMORY_REGION does not allow fine grained control over memory |
|
allocation and is deprecated. |
|
|
|
|
|
4.36 KVM_SET_TSS_ADDR |
|
--------------------- |
|
|
|
:Capability: KVM_CAP_SET_TSS_ADDR |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: unsigned long tss_address (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
This ioctl defines the physical address of a three-page region in the guest |
|
physical address space. The region must be within the first 4GB of the |
|
guest physical address space and must not conflict with any memory slot |
|
or any mmio address. The guest may malfunction if it accesses this memory |
|
region. |
|
|
|
This ioctl is required on Intel-based hosts. This is needed on Intel hardware |
|
because of a quirk in the virtualization implementation (see the internals |
|
documentation when it pops into existence). |
|
|
|
|
|
4.37 KVM_ENABLE_CAP |
|
------------------- |
|
|
|
:Capability: KVM_CAP_ENABLE_CAP |
|
:Architectures: mips, ppc, s390 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_enable_cap (in) |
|
:Returns: 0 on success; -1 on error |
|
|
|
:Capability: KVM_CAP_ENABLE_CAP_VM |
|
:Architectures: all |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_enable_cap (in) |
|
:Returns: 0 on success; -1 on error |
|
|
|
.. note:: |
|
|
|
Not all extensions are enabled by default. Using this ioctl the application |
|
can enable an extension, making it available to the guest. |
|
|
|
On systems that do not support this ioctl, it always fails. On systems that |
|
do support it, it only works for extensions that are supported for enablement. |
|
|
|
To check if a capability can be enabled, the KVM_CHECK_EXTENSION ioctl should |
|
be used. |
|
|
|
:: |
|
|
|
struct kvm_enable_cap { |
|
/* in */ |
|
__u32 cap; |
|
|
|
The capability that is supposed to get enabled. |
|
|
|
:: |
|
|
|
__u32 flags; |
|
|
|
A bitfield indicating future enhancements. Has to be 0 for now. |
|
|
|
:: |
|
|
|
__u64 args[4]; |
|
|
|
Arguments for enabling a feature. If a feature needs initial values to |
|
function properly, this is the place to put them. |
|
|
|
:: |
|
|
|
__u8 pad[64]; |
|
}; |
|
|
|
The vcpu ioctl should be used for vcpu-specific capabilities, the vm ioctl |
|
for vm-wide capabilities. |
|
|
|
4.38 KVM_GET_MP_STATE |
|
--------------------- |
|
|
|
:Capability: KVM_CAP_MP_STATE |
|
:Architectures: x86, s390, arm, arm64 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_mp_state (out) |
|
:Returns: 0 on success; -1 on error |
|
|
|
:: |
|
|
|
struct kvm_mp_state { |
|
__u32 mp_state; |
|
}; |
|
|
|
Returns the vcpu's current "multiprocessing state" (though also valid on |
|
uniprocessor guests). |
|
|
|
Possible values are: |
|
|
|
========================== =============================================== |
|
KVM_MP_STATE_RUNNABLE the vcpu is currently running [x86,arm/arm64] |
|
KVM_MP_STATE_UNINITIALIZED the vcpu is an application processor (AP) |
|
which has not yet received an INIT signal [x86] |
|
KVM_MP_STATE_INIT_RECEIVED the vcpu has received an INIT signal, and is |
|
now ready for a SIPI [x86] |
|
KVM_MP_STATE_HALTED the vcpu has executed a HLT instruction and |
|
is waiting for an interrupt [x86] |
|
KVM_MP_STATE_SIPI_RECEIVED the vcpu has just received a SIPI (vector |
|
accessible via KVM_GET_VCPU_EVENTS) [x86] |
|
KVM_MP_STATE_STOPPED the vcpu is stopped [s390,arm/arm64] |
|
KVM_MP_STATE_CHECK_STOP the vcpu is in a special error state [s390] |
|
KVM_MP_STATE_OPERATING the vcpu is operating (running or halted) |
|
[s390] |
|
KVM_MP_STATE_LOAD the vcpu is in a special load/startup state |
|
[s390] |
|
========================== =============================================== |
|
|
|
On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an |
|
in-kernel irqchip, the multiprocessing state must be maintained by userspace on |
|
these architectures. |
|
|
|
For arm/arm64: |
|
^^^^^^^^^^^^^^ |
|
|
|
The only states that are valid are KVM_MP_STATE_STOPPED and |
|
KVM_MP_STATE_RUNNABLE which reflect if the vcpu is paused or not. |
|
|
|
4.39 KVM_SET_MP_STATE |
|
--------------------- |
|
|
|
:Capability: KVM_CAP_MP_STATE |
|
:Architectures: x86, s390, arm, arm64 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_mp_state (in) |
|
:Returns: 0 on success; -1 on error |
|
|
|
Sets the vcpu's current "multiprocessing state"; see KVM_GET_MP_STATE for |
|
arguments. |
|
|
|
On x86, this ioctl is only useful after KVM_CREATE_IRQCHIP. Without an |
|
in-kernel irqchip, the multiprocessing state must be maintained by userspace on |
|
these architectures. |
|
|
|
For arm/arm64: |
|
^^^^^^^^^^^^^^ |
|
|
|
The only states that are valid are KVM_MP_STATE_STOPPED and |
|
KVM_MP_STATE_RUNNABLE which reflect if the vcpu should be paused or not. |
|
|
|
4.40 KVM_SET_IDENTITY_MAP_ADDR |
|
------------------------------ |
|
|
|
:Capability: KVM_CAP_SET_IDENTITY_MAP_ADDR |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: unsigned long identity (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
This ioctl defines the physical address of a one-page region in the guest |
|
physical address space. The region must be within the first 4GB of the |
|
guest physical address space and must not conflict with any memory slot |
|
or any mmio address. The guest may malfunction if it accesses this memory |
|
region. |
|
|
|
Setting the address to 0 will result in resetting the address to its default |
|
(0xfffbc000). |
|
|
|
This ioctl is required on Intel-based hosts. This is needed on Intel hardware |
|
because of a quirk in the virtualization implementation (see the internals |
|
documentation when it pops into existence). |
|
|
|
Fails if any VCPU has already been created. |
|
|
|
4.41 KVM_SET_BOOT_CPU_ID |
|
------------------------ |
|
|
|
:Capability: KVM_CAP_SET_BOOT_CPU_ID |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: unsigned long vcpu_id |
|
:Returns: 0 on success, -1 on error |
|
|
|
Define which vcpu is the Bootstrap Processor (BSP). Values are the same |
|
as the vcpu id in KVM_CREATE_VCPU. If this ioctl is not called, the default |
|
is vcpu 0. This ioctl has to be called before vcpu creation, |
|
otherwise it will return EBUSY error. |
|
|
|
|
|
4.42 KVM_GET_XSAVE |
|
------------------ |
|
|
|
:Capability: KVM_CAP_XSAVE |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_xsave (out) |
|
:Returns: 0 on success, -1 on error |
|
|
|
|
|
:: |
|
|
|
struct kvm_xsave { |
|
__u32 region[1024]; |
|
}; |
|
|
|
This ioctl would copy current vcpu's xsave struct to the userspace. |
|
|
|
|
|
4.43 KVM_SET_XSAVE |
|
------------------ |
|
|
|
:Capability: KVM_CAP_XSAVE |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_xsave (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
:: |
|
|
|
|
|
struct kvm_xsave { |
|
__u32 region[1024]; |
|
}; |
|
|
|
This ioctl would copy userspace's xsave struct to the kernel. |
|
|
|
|
|
4.44 KVM_GET_XCRS |
|
----------------- |
|
|
|
:Capability: KVM_CAP_XCRS |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_xcrs (out) |
|
:Returns: 0 on success, -1 on error |
|
|
|
:: |
|
|
|
struct kvm_xcr { |
|
__u32 xcr; |
|
__u32 reserved; |
|
__u64 value; |
|
}; |
|
|
|
struct kvm_xcrs { |
|
__u32 nr_xcrs; |
|
__u32 flags; |
|
struct kvm_xcr xcrs[KVM_MAX_XCRS]; |
|
__u64 padding[16]; |
|
}; |
|
|
|
This ioctl would copy current vcpu's xcrs to the userspace. |
|
|
|
|
|
4.45 KVM_SET_XCRS |
|
----------------- |
|
|
|
:Capability: KVM_CAP_XCRS |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_xcrs (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
:: |
|
|
|
struct kvm_xcr { |
|
__u32 xcr; |
|
__u32 reserved; |
|
__u64 value; |
|
}; |
|
|
|
struct kvm_xcrs { |
|
__u32 nr_xcrs; |
|
__u32 flags; |
|
struct kvm_xcr xcrs[KVM_MAX_XCRS]; |
|
__u64 padding[16]; |
|
}; |
|
|
|
This ioctl would set vcpu's xcr to the value userspace specified. |
|
|
|
|
|
4.46 KVM_GET_SUPPORTED_CPUID |
|
---------------------------- |
|
|
|
:Capability: KVM_CAP_EXT_CPUID |
|
:Architectures: x86 |
|
:Type: system ioctl |
|
:Parameters: struct kvm_cpuid2 (in/out) |
|
:Returns: 0 on success, -1 on error |
|
|
|
:: |
|
|
|
struct kvm_cpuid2 { |
|
__u32 nent; |
|
__u32 padding; |
|
struct kvm_cpuid_entry2 entries[0]; |
|
}; |
|
|
|
#define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0) |
|
#define KVM_CPUID_FLAG_STATEFUL_FUNC BIT(1) /* deprecated */ |
|
#define KVM_CPUID_FLAG_STATE_READ_NEXT BIT(2) /* deprecated */ |
|
|
|
struct kvm_cpuid_entry2 { |
|
__u32 function; |
|
__u32 index; |
|
__u32 flags; |
|
__u32 eax; |
|
__u32 ebx; |
|
__u32 ecx; |
|
__u32 edx; |
|
__u32 padding[3]; |
|
}; |
|
|
|
This ioctl returns x86 cpuid features which are supported by both the |
|
hardware and kvm in its default configuration. Userspace can use the |
|
information returned by this ioctl to construct cpuid information (for |
|
KVM_SET_CPUID2) that is consistent with hardware, kernel, and |
|
userspace capabilities, and with user requirements (for example, the |
|
user may wish to constrain cpuid to emulate older hardware, or for |
|
feature consistency across a cluster). |
|
|
|
Note that certain capabilities, such as KVM_CAP_X86_DISABLE_EXITS, may |
|
expose cpuid features (e.g. MONITOR) which are not supported by kvm in |
|
its default configuration. If userspace enables such capabilities, it |
|
is responsible for modifying the results of this ioctl appropriately. |
|
|
|
Userspace invokes KVM_GET_SUPPORTED_CPUID by passing a kvm_cpuid2 structure |
|
with the 'nent' field indicating the number of entries in the variable-size |
|
array 'entries'. If the number of entries is too low to describe the cpu |
|
capabilities, an error (E2BIG) is returned. If the number is too high, |
|
the 'nent' field is adjusted and an error (ENOMEM) is returned. If the |
|
number is just right, the 'nent' field is adjusted to the number of valid |
|
entries in the 'entries' array, which is then filled. |
|
|
|
The entries returned are the host cpuid as returned by the cpuid instruction, |
|
with unknown or unsupported features masked out. Some features (for example, |
|
x2apic), may not be present in the host cpu, but are exposed by kvm if it can |
|
emulate them efficiently. The fields in each entry are defined as follows: |
|
|
|
function: |
|
the eax value used to obtain the entry |
|
|
|
index: |
|
the ecx value used to obtain the entry (for entries that are |
|
affected by ecx) |
|
|
|
flags: |
|
an OR of zero or more of the following: |
|
|
|
KVM_CPUID_FLAG_SIGNIFCANT_INDEX: |
|
if the index field is valid |
|
|
|
eax, ebx, ecx, edx: |
|
the values returned by the cpuid instruction for |
|
this function/index combination |
|
|
|
The TSC deadline timer feature (CPUID leaf 1, ecx[24]) is always returned |
|
as false, since the feature depends on KVM_CREATE_IRQCHIP for local APIC |
|
support. Instead it is reported via:: |
|
|
|
ioctl(KVM_CHECK_EXTENSION, KVM_CAP_TSC_DEADLINE_TIMER) |
|
|
|
if that returns true and you use KVM_CREATE_IRQCHIP, or if you emulate the |
|
feature in userspace, then you can enable the feature for KVM_SET_CPUID2. |
|
|
|
|
|
4.47 KVM_PPC_GET_PVINFO |
|
----------------------- |
|
|
|
:Capability: KVM_CAP_PPC_GET_PVINFO |
|
:Architectures: ppc |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_ppc_pvinfo (out) |
|
:Returns: 0 on success, !0 on error |
|
|
|
:: |
|
|
|
struct kvm_ppc_pvinfo { |
|
__u32 flags; |
|
__u32 hcall[4]; |
|
__u8 pad[108]; |
|
}; |
|
|
|
This ioctl fetches PV specific information that need to be passed to the guest |
|
using the device tree or other means from vm context. |
|
|
|
The hcall array defines 4 instructions that make up a hypercall. |
|
|
|
If any additional field gets added to this structure later on, a bit for that |
|
additional piece of information will be set in the flags bitmap. |
|
|
|
The flags bitmap is defined as:: |
|
|
|
/* the host supports the ePAPR idle hcall |
|
#define KVM_PPC_PVINFO_FLAGS_EV_IDLE (1<<0) |
|
|
|
4.52 KVM_SET_GSI_ROUTING |
|
------------------------ |
|
|
|
:Capability: KVM_CAP_IRQ_ROUTING |
|
:Architectures: x86 s390 arm arm64 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_irq_routing (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Sets the GSI routing table entries, overwriting any previously set entries. |
|
|
|
On arm/arm64, GSI routing has the following limitation: |
|
|
|
- GSI routing does not apply to KVM_IRQ_LINE but only to KVM_IRQFD. |
|
|
|
:: |
|
|
|
struct kvm_irq_routing { |
|
__u32 nr; |
|
__u32 flags; |
|
struct kvm_irq_routing_entry entries[0]; |
|
}; |
|
|
|
No flags are specified so far, the corresponding field must be set to zero. |
|
|
|
:: |
|
|
|
struct kvm_irq_routing_entry { |
|
__u32 gsi; |
|
__u32 type; |
|
__u32 flags; |
|
__u32 pad; |
|
union { |
|
struct kvm_irq_routing_irqchip irqchip; |
|
struct kvm_irq_routing_msi msi; |
|
struct kvm_irq_routing_s390_adapter adapter; |
|
struct kvm_irq_routing_hv_sint hv_sint; |
|
__u32 pad[8]; |
|
} u; |
|
}; |
|
|
|
/* gsi routing entry types */ |
|
#define KVM_IRQ_ROUTING_IRQCHIP 1 |
|
#define KVM_IRQ_ROUTING_MSI 2 |
|
#define KVM_IRQ_ROUTING_S390_ADAPTER 3 |
|
#define KVM_IRQ_ROUTING_HV_SINT 4 |
|
|
|
flags: |
|
|
|
- KVM_MSI_VALID_DEVID: used along with KVM_IRQ_ROUTING_MSI routing entry |
|
type, specifies that the devid field contains a valid value. The per-VM |
|
KVM_CAP_MSI_DEVID capability advertises the requirement to provide |
|
the device ID. If this capability is not available, userspace should |
|
never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail. |
|
- zero otherwise |
|
|
|
:: |
|
|
|
struct kvm_irq_routing_irqchip { |
|
__u32 irqchip; |
|
__u32 pin; |
|
}; |
|
|
|
struct kvm_irq_routing_msi { |
|
__u32 address_lo; |
|
__u32 address_hi; |
|
__u32 data; |
|
union { |
|
__u32 pad; |
|
__u32 devid; |
|
}; |
|
}; |
|
|
|
If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier |
|
for the device that wrote the MSI message. For PCI, this is usually a |
|
BFD identifier in the lower 16 bits. |
|
|
|
On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS |
|
feature of KVM_CAP_X2APIC_API capability is enabled. If it is enabled, |
|
address_hi bits 31-8 provide bits 31-8 of the destination id. Bits 7-0 of |
|
address_hi must be zero. |
|
|
|
:: |
|
|
|
struct kvm_irq_routing_s390_adapter { |
|
__u64 ind_addr; |
|
__u64 summary_addr; |
|
__u64 ind_offset; |
|
__u32 summary_offset; |
|
__u32 adapter_id; |
|
}; |
|
|
|
struct kvm_irq_routing_hv_sint { |
|
__u32 vcpu; |
|
__u32 sint; |
|
}; |
|
|
|
|
|
4.55 KVM_SET_TSC_KHZ |
|
-------------------- |
|
|
|
:Capability: KVM_CAP_TSC_CONTROL |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: virtual tsc_khz |
|
:Returns: 0 on success, -1 on error |
|
|
|
Specifies the tsc frequency for the virtual machine. The unit of the |
|
frequency is KHz. |
|
|
|
|
|
4.56 KVM_GET_TSC_KHZ |
|
-------------------- |
|
|
|
:Capability: KVM_CAP_GET_TSC_KHZ |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: none |
|
:Returns: virtual tsc-khz on success, negative value on error |
|
|
|
Returns the tsc frequency of the guest. The unit of the return value is |
|
KHz. If the host has unstable tsc this ioctl returns -EIO instead as an |
|
error. |
|
|
|
|
|
4.57 KVM_GET_LAPIC |
|
------------------ |
|
|
|
:Capability: KVM_CAP_IRQCHIP |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_lapic_state (out) |
|
:Returns: 0 on success, -1 on error |
|
|
|
:: |
|
|
|
#define KVM_APIC_REG_SIZE 0x400 |
|
struct kvm_lapic_state { |
|
char regs[KVM_APIC_REG_SIZE]; |
|
}; |
|
|
|
Reads the Local APIC registers and copies them into the input argument. The |
|
data format and layout are the same as documented in the architecture manual. |
|
|
|
If KVM_X2APIC_API_USE_32BIT_IDS feature of KVM_CAP_X2APIC_API is |
|
enabled, then the format of APIC_ID register depends on the APIC mode |
|
(reported by MSR_IA32_APICBASE) of its VCPU. x2APIC stores APIC ID in |
|
the APIC_ID register (bytes 32-35). xAPIC only allows an 8-bit APIC ID |
|
which is stored in bits 31-24 of the APIC register, or equivalently in |
|
byte 35 of struct kvm_lapic_state's regs field. KVM_GET_LAPIC must then |
|
be called after MSR_IA32_APICBASE has been set with KVM_SET_MSR. |
|
|
|
If KVM_X2APIC_API_USE_32BIT_IDS feature is disabled, struct kvm_lapic_state |
|
always uses xAPIC format. |
|
|
|
|
|
4.58 KVM_SET_LAPIC |
|
------------------ |
|
|
|
:Capability: KVM_CAP_IRQCHIP |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_lapic_state (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
:: |
|
|
|
#define KVM_APIC_REG_SIZE 0x400 |
|
struct kvm_lapic_state { |
|
char regs[KVM_APIC_REG_SIZE]; |
|
}; |
|
|
|
Copies the input argument into the Local APIC registers. The data format |
|
and layout are the same as documented in the architecture manual. |
|
|
|
The format of the APIC ID register (bytes 32-35 of struct kvm_lapic_state's |
|
regs field) depends on the state of the KVM_CAP_X2APIC_API capability. |
|
See the note in KVM_GET_LAPIC. |
|
|
|
|
|
4.59 KVM_IOEVENTFD |
|
------------------ |
|
|
|
:Capability: KVM_CAP_IOEVENTFD |
|
:Architectures: all |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_ioeventfd (in) |
|
:Returns: 0 on success, !0 on error |
|
|
|
This ioctl attaches or detaches an ioeventfd to a legal pio/mmio address |
|
within the guest. A guest write in the registered address will signal the |
|
provided event instead of triggering an exit. |
|
|
|
:: |
|
|
|
struct kvm_ioeventfd { |
|
__u64 datamatch; |
|
__u64 addr; /* legal pio/mmio address */ |
|
__u32 len; /* 0, 1, 2, 4, or 8 bytes */ |
|
__s32 fd; |
|
__u32 flags; |
|
__u8 pad[36]; |
|
}; |
|
|
|
For the special case of virtio-ccw devices on s390, the ioevent is matched |
|
to a subchannel/virtqueue tuple instead. |
|
|
|
The following flags are defined:: |
|
|
|
#define KVM_IOEVENTFD_FLAG_DATAMATCH (1 << kvm_ioeventfd_flag_nr_datamatch) |
|
#define KVM_IOEVENTFD_FLAG_PIO (1 << kvm_ioeventfd_flag_nr_pio) |
|
#define KVM_IOEVENTFD_FLAG_DEASSIGN (1 << kvm_ioeventfd_flag_nr_deassign) |
|
#define KVM_IOEVENTFD_FLAG_VIRTIO_CCW_NOTIFY \ |
|
(1 << kvm_ioeventfd_flag_nr_virtio_ccw_notify) |
|
|
|
If datamatch flag is set, the event will be signaled only if the written value |
|
to the registered address is equal to datamatch in struct kvm_ioeventfd. |
|
|
|
For virtio-ccw devices, addr contains the subchannel id and datamatch the |
|
virtqueue index. |
|
|
|
With KVM_CAP_IOEVENTFD_ANY_LENGTH, a zero length ioeventfd is allowed, and |
|
the kernel will ignore the length of guest write and may get a faster vmexit. |
|
The speedup may only apply to specific architectures, but the ioeventfd will |
|
work anyway. |
|
|
|
4.60 KVM_DIRTY_TLB |
|
------------------ |
|
|
|
:Capability: KVM_CAP_SW_TLB |
|
:Architectures: ppc |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_dirty_tlb (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
:: |
|
|
|
struct kvm_dirty_tlb { |
|
__u64 bitmap; |
|
__u32 num_dirty; |
|
}; |
|
|
|
This must be called whenever userspace has changed an entry in the shared |
|
TLB, prior to calling KVM_RUN on the associated vcpu. |
|
|
|
The "bitmap" field is the userspace address of an array. This array |
|
consists of a number of bits, equal to the total number of TLB entries as |
|
determined by the last successful call to KVM_CONFIG_TLB, rounded up to the |
|
nearest multiple of 64. |
|
|
|
Each bit corresponds to one TLB entry, ordered the same as in the shared TLB |
|
array. |
|
|
|
The array is little-endian: the bit 0 is the least significant bit of the |
|
first byte, bit 8 is the least significant bit of the second byte, etc. |
|
This avoids any complications with differing word sizes. |
|
|
|
The "num_dirty" field is a performance hint for KVM to determine whether it |
|
should skip processing the bitmap and just invalidate everything. It must |
|
be set to the number of set bits in the bitmap. |
|
|
|
|
|
4.62 KVM_CREATE_SPAPR_TCE |
|
------------------------- |
|
|
|
:Capability: KVM_CAP_SPAPR_TCE |
|
:Architectures: powerpc |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_create_spapr_tce (in) |
|
:Returns: file descriptor for manipulating the created TCE table |
|
|
|
This creates a virtual TCE (translation control entry) table, which |
|
is an IOMMU for PAPR-style virtual I/O. It is used to translate |
|
logical addresses used in virtual I/O into guest physical addresses, |
|
and provides a scatter/gather capability for PAPR virtual I/O. |
|
|
|
:: |
|
|
|
/* for KVM_CAP_SPAPR_TCE */ |
|
struct kvm_create_spapr_tce { |
|
__u64 liobn; |
|
__u32 window_size; |
|
}; |
|
|
|
The liobn field gives the logical IO bus number for which to create a |
|
TCE table. The window_size field specifies the size of the DMA window |
|
which this TCE table will translate - the table will contain one 64 |
|
bit TCE entry for every 4kiB of the DMA window. |
|
|
|
When the guest issues an H_PUT_TCE hcall on a liobn for which a TCE |
|
table has been created using this ioctl(), the kernel will handle it |
|
in real mode, updating the TCE table. H_PUT_TCE calls for other |
|
liobns will cause a vm exit and must be handled by userspace. |
|
|
|
The return value is a file descriptor which can be passed to mmap(2) |
|
to map the created TCE table into userspace. This lets userspace read |
|
the entries written by kernel-handled H_PUT_TCE calls, and also lets |
|
userspace update the TCE table directly which is useful in some |
|
circumstances. |
|
|
|
|
|
4.63 KVM_ALLOCATE_RMA |
|
--------------------- |
|
|
|
:Capability: KVM_CAP_PPC_RMA |
|
:Architectures: powerpc |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_allocate_rma (out) |
|
:Returns: file descriptor for mapping the allocated RMA |
|
|
|
This allocates a Real Mode Area (RMA) from the pool allocated at boot |
|
time by the kernel. An RMA is a physically-contiguous, aligned region |
|
of memory used on older POWER processors to provide the memory which |
|
will be accessed by real-mode (MMU off) accesses in a KVM guest. |
|
POWER processors support a set of sizes for the RMA that usually |
|
includes 64MB, 128MB, 256MB and some larger powers of two. |
|
|
|
:: |
|
|
|
/* for KVM_ALLOCATE_RMA */ |
|
struct kvm_allocate_rma { |
|
__u64 rma_size; |
|
}; |
|
|
|
The return value is a file descriptor which can be passed to mmap(2) |
|
to map the allocated RMA into userspace. The mapped area can then be |
|
passed to the KVM_SET_USER_MEMORY_REGION ioctl to establish it as the |
|
RMA for a virtual machine. The size of the RMA in bytes (which is |
|
fixed at host kernel boot time) is returned in the rma_size field of |
|
the argument structure. |
|
|
|
The KVM_CAP_PPC_RMA capability is 1 or 2 if the KVM_ALLOCATE_RMA ioctl |
|
is supported; 2 if the processor requires all virtual machines to have |
|
an RMA, or 1 if the processor can use an RMA but doesn't require it, |
|
because it supports the Virtual RMA (VRMA) facility. |
|
|
|
|
|
4.64 KVM_NMI |
|
------------ |
|
|
|
:Capability: KVM_CAP_USER_NMI |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: none |
|
:Returns: 0 on success, -1 on error |
|
|
|
Queues an NMI on the thread's vcpu. Note this is well defined only |
|
when KVM_CREATE_IRQCHIP has not been called, since this is an interface |
|
between the virtual cpu core and virtual local APIC. After KVM_CREATE_IRQCHIP |
|
has been called, this interface is completely emulated within the kernel. |
|
|
|
To use this to emulate the LINT1 input with KVM_CREATE_IRQCHIP, use the |
|
following algorithm: |
|
|
|
- pause the vcpu |
|
- read the local APIC's state (KVM_GET_LAPIC) |
|
- check whether changing LINT1 will queue an NMI (see the LVT entry for LINT1) |
|
- if so, issue KVM_NMI |
|
- resume the vcpu |
|
|
|
Some guests configure the LINT1 NMI input to cause a panic, aiding in |
|
debugging. |
|
|
|
|
|
4.65 KVM_S390_UCAS_MAP |
|
---------------------- |
|
|
|
:Capability: KVM_CAP_S390_UCONTROL |
|
:Architectures: s390 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_s390_ucas_mapping (in) |
|
:Returns: 0 in case of success |
|
|
|
The parameter is defined like this:: |
|
|
|
struct kvm_s390_ucas_mapping { |
|
__u64 user_addr; |
|
__u64 vcpu_addr; |
|
__u64 length; |
|
}; |
|
|
|
This ioctl maps the memory at "user_addr" with the length "length" to |
|
the vcpu's address space starting at "vcpu_addr". All parameters need to |
|
be aligned by 1 megabyte. |
|
|
|
|
|
4.66 KVM_S390_UCAS_UNMAP |
|
------------------------ |
|
|
|
:Capability: KVM_CAP_S390_UCONTROL |
|
:Architectures: s390 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_s390_ucas_mapping (in) |
|
:Returns: 0 in case of success |
|
|
|
The parameter is defined like this:: |
|
|
|
struct kvm_s390_ucas_mapping { |
|
__u64 user_addr; |
|
__u64 vcpu_addr; |
|
__u64 length; |
|
}; |
|
|
|
This ioctl unmaps the memory in the vcpu's address space starting at |
|
"vcpu_addr" with the length "length". The field "user_addr" is ignored. |
|
All parameters need to be aligned by 1 megabyte. |
|
|
|
|
|
4.67 KVM_S390_VCPU_FAULT |
|
------------------------ |
|
|
|
:Capability: KVM_CAP_S390_UCONTROL |
|
:Architectures: s390 |
|
:Type: vcpu ioctl |
|
:Parameters: vcpu absolute address (in) |
|
:Returns: 0 in case of success |
|
|
|
This call creates a page table entry on the virtual cpu's address space |
|
(for user controlled virtual machines) or the virtual machine's address |
|
space (for regular virtual machines). This only works for minor faults, |
|
thus it's recommended to access subject memory page via the user page |
|
table upfront. This is useful to handle validity intercepts for user |
|
controlled virtual machines to fault in the virtual cpu's lowcore pages |
|
prior to calling the KVM_RUN ioctl. |
|
|
|
|
|
4.68 KVM_SET_ONE_REG |
|
-------------------- |
|
|
|
:Capability: KVM_CAP_ONE_REG |
|
:Architectures: all |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_one_reg (in) |
|
:Returns: 0 on success, negative value on failure |
|
|
|
Errors: |
|
|
|
====== ============================================================ |
|
ENOENT no such register |
|
EINVAL invalid register ID, or no such register or used with VMs in |
|
protected virtualization mode on s390 |
|
EPERM (arm64) register access not allowed before vcpu finalization |
|
====== ============================================================ |
|
|
|
(These error codes are indicative only: do not rely on a specific error |
|
code being returned in a specific situation.) |
|
|
|
:: |
|
|
|
struct kvm_one_reg { |
|
__u64 id; |
|
__u64 addr; |
|
}; |
|
|
|
Using this ioctl, a single vcpu register can be set to a specific value |
|
defined by user space with the passed in struct kvm_one_reg, where id |
|
refers to the register identifier as described below and addr is a pointer |
|
to a variable with the respective size. There can be architecture agnostic |
|
and architecture specific registers. Each have their own range of operation |
|
and their own constants and width. To keep track of the implemented |
|
registers, find a list below: |
|
|
|
======= =============================== ============ |
|
Arch Register Width (bits) |
|
======= =============================== ============ |
|
PPC KVM_REG_PPC_HIOR 64 |
|
PPC KVM_REG_PPC_IAC1 64 |
|
PPC KVM_REG_PPC_IAC2 64 |
|
PPC KVM_REG_PPC_IAC3 64 |
|
PPC KVM_REG_PPC_IAC4 64 |
|
PPC KVM_REG_PPC_DAC1 64 |
|
PPC KVM_REG_PPC_DAC2 64 |
|
PPC KVM_REG_PPC_DABR 64 |
|
PPC KVM_REG_PPC_DSCR 64 |
|
PPC KVM_REG_PPC_PURR 64 |
|
PPC KVM_REG_PPC_SPURR 64 |
|
PPC KVM_REG_PPC_DAR 64 |
|
PPC KVM_REG_PPC_DSISR 32 |
|
PPC KVM_REG_PPC_AMR 64 |
|
PPC KVM_REG_PPC_UAMOR 64 |
|
PPC KVM_REG_PPC_MMCR0 64 |
|
PPC KVM_REG_PPC_MMCR1 64 |
|
PPC KVM_REG_PPC_MMCRA 64 |
|
PPC KVM_REG_PPC_MMCR2 64 |
|
PPC KVM_REG_PPC_MMCRS 64 |
|
PPC KVM_REG_PPC_MMCR3 64 |
|
PPC KVM_REG_PPC_SIAR 64 |
|
PPC KVM_REG_PPC_SDAR 64 |
|
PPC KVM_REG_PPC_SIER 64 |
|
PPC KVM_REG_PPC_SIER2 64 |
|
PPC KVM_REG_PPC_SIER3 64 |
|
PPC KVM_REG_PPC_PMC1 32 |
|
PPC KVM_REG_PPC_PMC2 32 |
|
PPC KVM_REG_PPC_PMC3 32 |
|
PPC KVM_REG_PPC_PMC4 32 |
|
PPC KVM_REG_PPC_PMC5 32 |
|
PPC KVM_REG_PPC_PMC6 32 |
|
PPC KVM_REG_PPC_PMC7 32 |
|
PPC KVM_REG_PPC_PMC8 32 |
|
PPC KVM_REG_PPC_FPR0 64 |
|
... |
|
PPC KVM_REG_PPC_FPR31 64 |
|
PPC KVM_REG_PPC_VR0 128 |
|
... |
|
PPC KVM_REG_PPC_VR31 128 |
|
PPC KVM_REG_PPC_VSR0 128 |
|
... |
|
PPC KVM_REG_PPC_VSR31 128 |
|
PPC KVM_REG_PPC_FPSCR 64 |
|
PPC KVM_REG_PPC_VSCR 32 |
|
PPC KVM_REG_PPC_VPA_ADDR 64 |
|
PPC KVM_REG_PPC_VPA_SLB 128 |
|
PPC KVM_REG_PPC_VPA_DTL 128 |
|
PPC KVM_REG_PPC_EPCR 32 |
|
PPC KVM_REG_PPC_EPR 32 |
|
PPC KVM_REG_PPC_TCR 32 |
|
PPC KVM_REG_PPC_TSR 32 |
|
PPC KVM_REG_PPC_OR_TSR 32 |
|
PPC KVM_REG_PPC_CLEAR_TSR 32 |
|
PPC KVM_REG_PPC_MAS0 32 |
|
PPC KVM_REG_PPC_MAS1 32 |
|
PPC KVM_REG_PPC_MAS2 64 |
|
PPC KVM_REG_PPC_MAS7_3 64 |
|
PPC KVM_REG_PPC_MAS4 32 |
|
PPC KVM_REG_PPC_MAS6 32 |
|
PPC KVM_REG_PPC_MMUCFG 32 |
|
PPC KVM_REG_PPC_TLB0CFG 32 |
|
PPC KVM_REG_PPC_TLB1CFG 32 |
|
PPC KVM_REG_PPC_TLB2CFG 32 |
|
PPC KVM_REG_PPC_TLB3CFG 32 |
|
PPC KVM_REG_PPC_TLB0PS 32 |
|
PPC KVM_REG_PPC_TLB1PS 32 |
|
PPC KVM_REG_PPC_TLB2PS 32 |
|
PPC KVM_REG_PPC_TLB3PS 32 |
|
PPC KVM_REG_PPC_EPTCFG 32 |
|
PPC KVM_REG_PPC_ICP_STATE 64 |
|
PPC KVM_REG_PPC_VP_STATE 128 |
|
PPC KVM_REG_PPC_TB_OFFSET 64 |
|
PPC KVM_REG_PPC_SPMC1 32 |
|
PPC KVM_REG_PPC_SPMC2 32 |
|
PPC KVM_REG_PPC_IAMR 64 |
|
PPC KVM_REG_PPC_TFHAR 64 |
|
PPC KVM_REG_PPC_TFIAR 64 |
|
PPC KVM_REG_PPC_TEXASR 64 |
|
PPC KVM_REG_PPC_FSCR 64 |
|
PPC KVM_REG_PPC_PSPB 32 |
|
PPC KVM_REG_PPC_EBBHR 64 |
|
PPC KVM_REG_PPC_EBBRR 64 |
|
PPC KVM_REG_PPC_BESCR 64 |
|
PPC KVM_REG_PPC_TAR 64 |
|
PPC KVM_REG_PPC_DPDES 64 |
|
PPC KVM_REG_PPC_DAWR 64 |
|
PPC KVM_REG_PPC_DAWRX 64 |
|
PPC KVM_REG_PPC_CIABR 64 |
|
PPC KVM_REG_PPC_IC 64 |
|
PPC KVM_REG_PPC_VTB 64 |
|
PPC KVM_REG_PPC_CSIGR 64 |
|
PPC KVM_REG_PPC_TACR 64 |
|
PPC KVM_REG_PPC_TCSCR 64 |
|
PPC KVM_REG_PPC_PID 64 |
|
PPC KVM_REG_PPC_ACOP 64 |
|
PPC KVM_REG_PPC_VRSAVE 32 |
|
PPC KVM_REG_PPC_LPCR 32 |
|
PPC KVM_REG_PPC_LPCR_64 64 |
|
PPC KVM_REG_PPC_PPR 64 |
|
PPC KVM_REG_PPC_ARCH_COMPAT 32 |
|
PPC KVM_REG_PPC_DABRX 32 |
|
PPC KVM_REG_PPC_WORT 64 |
|
PPC KVM_REG_PPC_SPRG9 64 |
|
PPC KVM_REG_PPC_DBSR 32 |
|
PPC KVM_REG_PPC_TIDR 64 |
|
PPC KVM_REG_PPC_PSSCR 64 |
|
PPC KVM_REG_PPC_DEC_EXPIRY 64 |
|
PPC KVM_REG_PPC_PTCR 64 |
|
PPC KVM_REG_PPC_DAWR1 64 |
|
PPC KVM_REG_PPC_DAWRX1 64 |
|
PPC KVM_REG_PPC_TM_GPR0 64 |
|
... |
|
PPC KVM_REG_PPC_TM_GPR31 64 |
|
PPC KVM_REG_PPC_TM_VSR0 128 |
|
... |
|
PPC KVM_REG_PPC_TM_VSR63 128 |
|
PPC KVM_REG_PPC_TM_CR 64 |
|
PPC KVM_REG_PPC_TM_LR 64 |
|
PPC KVM_REG_PPC_TM_CTR 64 |
|
PPC KVM_REG_PPC_TM_FPSCR 64 |
|
PPC KVM_REG_PPC_TM_AMR 64 |
|
PPC KVM_REG_PPC_TM_PPR 64 |
|
PPC KVM_REG_PPC_TM_VRSAVE 64 |
|
PPC KVM_REG_PPC_TM_VSCR 32 |
|
PPC KVM_REG_PPC_TM_DSCR 64 |
|
PPC KVM_REG_PPC_TM_TAR 64 |
|
PPC KVM_REG_PPC_TM_XER 64 |
|
|
|
MIPS KVM_REG_MIPS_R0 64 |
|
... |
|
MIPS KVM_REG_MIPS_R31 64 |
|
MIPS KVM_REG_MIPS_HI 64 |
|
MIPS KVM_REG_MIPS_LO 64 |
|
MIPS KVM_REG_MIPS_PC 64 |
|
MIPS KVM_REG_MIPS_CP0_INDEX 32 |
|
MIPS KVM_REG_MIPS_CP0_ENTRYLO0 64 |
|
MIPS KVM_REG_MIPS_CP0_ENTRYLO1 64 |
|
MIPS KVM_REG_MIPS_CP0_CONTEXT 64 |
|
MIPS KVM_REG_MIPS_CP0_CONTEXTCONFIG 32 |
|
MIPS KVM_REG_MIPS_CP0_USERLOCAL 64 |
|
MIPS KVM_REG_MIPS_CP0_XCONTEXTCONFIG 64 |
|
MIPS KVM_REG_MIPS_CP0_PAGEMASK 32 |
|
MIPS KVM_REG_MIPS_CP0_PAGEGRAIN 32 |
|
MIPS KVM_REG_MIPS_CP0_SEGCTL0 64 |
|
MIPS KVM_REG_MIPS_CP0_SEGCTL1 64 |
|
MIPS KVM_REG_MIPS_CP0_SEGCTL2 64 |
|
MIPS KVM_REG_MIPS_CP0_PWBASE 64 |
|
MIPS KVM_REG_MIPS_CP0_PWFIELD 64 |
|
MIPS KVM_REG_MIPS_CP0_PWSIZE 64 |
|
MIPS KVM_REG_MIPS_CP0_WIRED 32 |
|
MIPS KVM_REG_MIPS_CP0_PWCTL 32 |
|
MIPS KVM_REG_MIPS_CP0_HWRENA 32 |
|
MIPS KVM_REG_MIPS_CP0_BADVADDR 64 |
|
MIPS KVM_REG_MIPS_CP0_BADINSTR 32 |
|
MIPS KVM_REG_MIPS_CP0_BADINSTRP 32 |
|
MIPS KVM_REG_MIPS_CP0_COUNT 32 |
|
MIPS KVM_REG_MIPS_CP0_ENTRYHI 64 |
|
MIPS KVM_REG_MIPS_CP0_COMPARE 32 |
|
MIPS KVM_REG_MIPS_CP0_STATUS 32 |
|
MIPS KVM_REG_MIPS_CP0_INTCTL 32 |
|
MIPS KVM_REG_MIPS_CP0_CAUSE 32 |
|
MIPS KVM_REG_MIPS_CP0_EPC 64 |
|
MIPS KVM_REG_MIPS_CP0_PRID 32 |
|
MIPS KVM_REG_MIPS_CP0_EBASE 64 |
|
MIPS KVM_REG_MIPS_CP0_CONFIG 32 |
|
MIPS KVM_REG_MIPS_CP0_CONFIG1 32 |
|
MIPS KVM_REG_MIPS_CP0_CONFIG2 32 |
|
MIPS KVM_REG_MIPS_CP0_CONFIG3 32 |
|
MIPS KVM_REG_MIPS_CP0_CONFIG4 32 |
|
MIPS KVM_REG_MIPS_CP0_CONFIG5 32 |
|
MIPS KVM_REG_MIPS_CP0_CONFIG7 32 |
|
MIPS KVM_REG_MIPS_CP0_XCONTEXT 64 |
|
MIPS KVM_REG_MIPS_CP0_ERROREPC 64 |
|
MIPS KVM_REG_MIPS_CP0_KSCRATCH1 64 |
|
MIPS KVM_REG_MIPS_CP0_KSCRATCH2 64 |
|
MIPS KVM_REG_MIPS_CP0_KSCRATCH3 64 |
|
MIPS KVM_REG_MIPS_CP0_KSCRATCH4 64 |
|
MIPS KVM_REG_MIPS_CP0_KSCRATCH5 64 |
|
MIPS KVM_REG_MIPS_CP0_KSCRATCH6 64 |
|
MIPS KVM_REG_MIPS_CP0_MAAR(0..63) 64 |
|
MIPS KVM_REG_MIPS_COUNT_CTL 64 |
|
MIPS KVM_REG_MIPS_COUNT_RESUME 64 |
|
MIPS KVM_REG_MIPS_COUNT_HZ 64 |
|
MIPS KVM_REG_MIPS_FPR_32(0..31) 32 |
|
MIPS KVM_REG_MIPS_FPR_64(0..31) 64 |
|
MIPS KVM_REG_MIPS_VEC_128(0..31) 128 |
|
MIPS KVM_REG_MIPS_FCR_IR 32 |
|
MIPS KVM_REG_MIPS_FCR_CSR 32 |
|
MIPS KVM_REG_MIPS_MSA_IR 32 |
|
MIPS KVM_REG_MIPS_MSA_CSR 32 |
|
======= =============================== ============ |
|
|
|
ARM registers are mapped using the lower 32 bits. The upper 16 of that |
|
is the register group type, or coprocessor number: |
|
|
|
ARM core registers have the following id bit patterns:: |
|
|
|
0x4020 0000 0010 <index into the kvm_regs struct:16> |
|
|
|
ARM 32-bit CP15 registers have the following id bit patterns:: |
|
|
|
0x4020 0000 000F <zero:1> <crn:4> <crm:4> <opc1:4> <opc2:3> |
|
|
|
ARM 64-bit CP15 registers have the following id bit patterns:: |
|
|
|
0x4030 0000 000F <zero:1> <zero:4> <crm:4> <opc1:4> <zero:3> |
|
|
|
ARM CCSIDR registers are demultiplexed by CSSELR value:: |
|
|
|
0x4020 0000 0011 00 <csselr:8> |
|
|
|
ARM 32-bit VFP control registers have the following id bit patterns:: |
|
|
|
0x4020 0000 0012 1 <regno:12> |
|
|
|
ARM 64-bit FP registers have the following id bit patterns:: |
|
|
|
0x4030 0000 0012 0 <regno:12> |
|
|
|
ARM firmware pseudo-registers have the following bit pattern:: |
|
|
|
0x4030 0000 0014 <regno:16> |
|
|
|
|
|
arm64 registers are mapped using the lower 32 bits. The upper 16 of |
|
that is the register group type, or coprocessor number: |
|
|
|
arm64 core/FP-SIMD registers have the following id bit patterns. Note |
|
that the size of the access is variable, as the kvm_regs structure |
|
contains elements ranging from 32 to 128 bits. The index is a 32bit |
|
value in the kvm_regs structure seen as a 32bit array:: |
|
|
|
0x60x0 0000 0010 <index into the kvm_regs struct:16> |
|
|
|
Specifically: |
|
|
|
======================= ========= ===== ======================================= |
|
Encoding Register Bits kvm_regs member |
|
======================= ========= ===== ======================================= |
|
0x6030 0000 0010 0000 X0 64 regs.regs[0] |
|
0x6030 0000 0010 0002 X1 64 regs.regs[1] |
|
... |
|
0x6030 0000 0010 003c X30 64 regs.regs[30] |
|
0x6030 0000 0010 003e SP 64 regs.sp |
|
0x6030 0000 0010 0040 PC 64 regs.pc |
|
0x6030 0000 0010 0042 PSTATE 64 regs.pstate |
|
0x6030 0000 0010 0044 SP_EL1 64 sp_el1 |
|
0x6030 0000 0010 0046 ELR_EL1 64 elr_el1 |
|
0x6030 0000 0010 0048 SPSR_EL1 64 spsr[KVM_SPSR_EL1] (alias SPSR_SVC) |
|
0x6030 0000 0010 004a SPSR_ABT 64 spsr[KVM_SPSR_ABT] |
|
0x6030 0000 0010 004c SPSR_UND 64 spsr[KVM_SPSR_UND] |
|
0x6030 0000 0010 004e SPSR_IRQ 64 spsr[KVM_SPSR_IRQ] |
|
0x6060 0000 0010 0050 SPSR_FIQ 64 spsr[KVM_SPSR_FIQ] |
|
0x6040 0000 0010 0054 V0 128 fp_regs.vregs[0] [1]_ |
|
0x6040 0000 0010 0058 V1 128 fp_regs.vregs[1] [1]_ |
|
... |
|
0x6040 0000 0010 00d0 V31 128 fp_regs.vregs[31] [1]_ |
|
0x6020 0000 0010 00d4 FPSR 32 fp_regs.fpsr |
|
0x6020 0000 0010 00d5 FPCR 32 fp_regs.fpcr |
|
======================= ========= ===== ======================================= |
|
|
|
.. [1] These encodings are not accepted for SVE-enabled vcpus. See |
|
KVM_ARM_VCPU_INIT. |
|
|
|
The equivalent register content can be accessed via bits [127:0] of |
|
the corresponding SVE Zn registers instead for vcpus that have SVE |
|
enabled (see below). |
|
|
|
arm64 CCSIDR registers are demultiplexed by CSSELR value:: |
|
|
|
0x6020 0000 0011 00 <csselr:8> |
|
|
|
arm64 system registers have the following id bit patterns:: |
|
|
|
0x6030 0000 0013 <op0:2> <op1:3> <crn:4> <crm:4> <op2:3> |
|
|
|
.. warning:: |
|
|
|
Two system register IDs do not follow the specified pattern. These |
|
are KVM_REG_ARM_TIMER_CVAL and KVM_REG_ARM_TIMER_CNT, which map to |
|
system registers CNTV_CVAL_EL0 and CNTVCT_EL0 respectively. These |
|
two had their values accidentally swapped, which means TIMER_CVAL is |
|
derived from the register encoding for CNTVCT_EL0 and TIMER_CNT is |
|
derived from the register encoding for CNTV_CVAL_EL0. As this is |
|
API, it must remain this way. |
|
|
|
arm64 firmware pseudo-registers have the following bit pattern:: |
|
|
|
0x6030 0000 0014 <regno:16> |
|
|
|
arm64 SVE registers have the following bit patterns:: |
|
|
|
0x6080 0000 0015 00 <n:5> <slice:5> Zn bits[2048*slice + 2047 : 2048*slice] |
|
0x6050 0000 0015 04 <n:4> <slice:5> Pn bits[256*slice + 255 : 256*slice] |
|
0x6050 0000 0015 060 <slice:5> FFR bits[256*slice + 255 : 256*slice] |
|
0x6060 0000 0015 ffff KVM_REG_ARM64_SVE_VLS pseudo-register |
|
|
|
Access to register IDs where 2048 * slice >= 128 * max_vq will fail with |
|
ENOENT. max_vq is the vcpu's maximum supported vector length in 128-bit |
|
quadwords: see [2]_ below. |
|
|
|
These registers are only accessible on vcpus for which SVE is enabled. |
|
See KVM_ARM_VCPU_INIT for details. |
|
|
|
In addition, except for KVM_REG_ARM64_SVE_VLS, these registers are not |
|
accessible until the vcpu's SVE configuration has been finalized |
|
using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE). See KVM_ARM_VCPU_INIT |
|
and KVM_ARM_VCPU_FINALIZE for more information about this procedure. |
|
|
|
KVM_REG_ARM64_SVE_VLS is a pseudo-register that allows the set of vector |
|
lengths supported by the vcpu to be discovered and configured by |
|
userspace. When transferred to or from user memory via KVM_GET_ONE_REG |
|
or KVM_SET_ONE_REG, the value of this register is of type |
|
__u64[KVM_ARM64_SVE_VLS_WORDS], and encodes the set of vector lengths as |
|
follows:: |
|
|
|
__u64 vector_lengths[KVM_ARM64_SVE_VLS_WORDS]; |
|
|
|
if (vq >= SVE_VQ_MIN && vq <= SVE_VQ_MAX && |
|
((vector_lengths[(vq - KVM_ARM64_SVE_VQ_MIN) / 64] >> |
|
((vq - KVM_ARM64_SVE_VQ_MIN) % 64)) & 1)) |
|
/* Vector length vq * 16 bytes supported */ |
|
else |
|
/* Vector length vq * 16 bytes not supported */ |
|
|
|
.. [2] The maximum value vq for which the above condition is true is |
|
max_vq. This is the maximum vector length available to the guest on |
|
this vcpu, and determines which register slices are visible through |
|
this ioctl interface. |
|
|
|
(See Documentation/arm64/sve.rst for an explanation of the "vq" |
|
nomenclature.) |
|
|
|
KVM_REG_ARM64_SVE_VLS is only accessible after KVM_ARM_VCPU_INIT. |
|
KVM_ARM_VCPU_INIT initialises it to the best set of vector lengths that |
|
the host supports. |
|
|
|
Userspace may subsequently modify it if desired until the vcpu's SVE |
|
configuration is finalized using KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE). |
|
|
|
Apart from simply removing all vector lengths from the host set that |
|
exceed some value, support for arbitrarily chosen sets of vector lengths |
|
is hardware-dependent and may not be available. Attempting to configure |
|
an invalid set of vector lengths via KVM_SET_ONE_REG will fail with |
|
EINVAL. |
|
|
|
After the vcpu's SVE configuration is finalized, further attempts to |
|
write this register will fail with EPERM. |
|
|
|
|
|
MIPS registers are mapped using the lower 32 bits. The upper 16 of that is |
|
the register group type: |
|
|
|
MIPS core registers (see above) have the following id bit patterns:: |
|
|
|
0x7030 0000 0000 <reg:16> |
|
|
|
MIPS CP0 registers (see KVM_REG_MIPS_CP0_* above) have the following id bit |
|
patterns depending on whether they're 32-bit or 64-bit registers:: |
|
|
|
0x7020 0000 0001 00 <reg:5> <sel:3> (32-bit) |
|
0x7030 0000 0001 00 <reg:5> <sel:3> (64-bit) |
|
|
|
Note: KVM_REG_MIPS_CP0_ENTRYLO0 and KVM_REG_MIPS_CP0_ENTRYLO1 are the MIPS64 |
|
versions of the EntryLo registers regardless of the word size of the host |
|
hardware, host kernel, guest, and whether XPA is present in the guest, i.e. |
|
with the RI and XI bits (if they exist) in bits 63 and 62 respectively, and |
|
the PFNX field starting at bit 30. |
|
|
|
MIPS MAARs (see KVM_REG_MIPS_CP0_MAAR(*) above) have the following id bit |
|
patterns:: |
|
|
|
0x7030 0000 0001 01 <reg:8> |
|
|
|
MIPS KVM control registers (see above) have the following id bit patterns:: |
|
|
|
0x7030 0000 0002 <reg:16> |
|
|
|
MIPS FPU registers (see KVM_REG_MIPS_FPR_{32,64}() above) have the following |
|
id bit patterns depending on the size of the register being accessed. They are |
|
always accessed according to the current guest FPU mode (Status.FR and |
|
Config5.FRE), i.e. as the guest would see them, and they become unpredictable |
|
if the guest FPU mode is changed. MIPS SIMD Architecture (MSA) vector |
|
registers (see KVM_REG_MIPS_VEC_128() above) have similar patterns as they |
|
overlap the FPU registers:: |
|
|
|
0x7020 0000 0003 00 <0:3> <reg:5> (32-bit FPU registers) |
|
0x7030 0000 0003 00 <0:3> <reg:5> (64-bit FPU registers) |
|
0x7040 0000 0003 00 <0:3> <reg:5> (128-bit MSA vector registers) |
|
|
|
MIPS FPU control registers (see KVM_REG_MIPS_FCR_{IR,CSR} above) have the |
|
following id bit patterns:: |
|
|
|
0x7020 0000 0003 01 <0:3> <reg:5> |
|
|
|
MIPS MSA control registers (see KVM_REG_MIPS_MSA_{IR,CSR} above) have the |
|
following id bit patterns:: |
|
|
|
0x7020 0000 0003 02 <0:3> <reg:5> |
|
|
|
|
|
4.69 KVM_GET_ONE_REG |
|
-------------------- |
|
|
|
:Capability: KVM_CAP_ONE_REG |
|
:Architectures: all |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_one_reg (in and out) |
|
:Returns: 0 on success, negative value on failure |
|
|
|
Errors include: |
|
|
|
======== ============================================================ |
|
ENOENT no such register |
|
EINVAL invalid register ID, or no such register or used with VMs in |
|
protected virtualization mode on s390 |
|
EPERM (arm64) register access not allowed before vcpu finalization |
|
======== ============================================================ |
|
|
|
(These error codes are indicative only: do not rely on a specific error |
|
code being returned in a specific situation.) |
|
|
|
This ioctl allows to receive the value of a single register implemented |
|
in a vcpu. The register to read is indicated by the "id" field of the |
|
kvm_one_reg struct passed in. On success, the register value can be found |
|
at the memory location pointed to by "addr". |
|
|
|
The list of registers accessible using this interface is identical to the |
|
list in 4.68. |
|
|
|
|
|
4.70 KVM_KVMCLOCK_CTRL |
|
---------------------- |
|
|
|
:Capability: KVM_CAP_KVMCLOCK_CTRL |
|
:Architectures: Any that implement pvclocks (currently x86 only) |
|
:Type: vcpu ioctl |
|
:Parameters: None |
|
:Returns: 0 on success, -1 on error |
|
|
|
This ioctl sets a flag accessible to the guest indicating that the specified |
|
vCPU has been paused by the host userspace. |
|
|
|
The host will set a flag in the pvclock structure that is checked from the |
|
soft lockup watchdog. The flag is part of the pvclock structure that is |
|
shared between guest and host, specifically the second bit of the flags |
|
field of the pvclock_vcpu_time_info structure. It will be set exclusively by |
|
the host and read/cleared exclusively by the guest. The guest operation of |
|
checking and clearing the flag must be an atomic operation so |
|
load-link/store-conditional, or equivalent must be used. There are two cases |
|
where the guest will clear the flag: when the soft lockup watchdog timer resets |
|
itself or when a soft lockup is detected. This ioctl can be called any time |
|
after pausing the vcpu, but before it is resumed. |
|
|
|
|
|
4.71 KVM_SIGNAL_MSI |
|
------------------- |
|
|
|
:Capability: KVM_CAP_SIGNAL_MSI |
|
:Architectures: x86 arm arm64 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_msi (in) |
|
:Returns: >0 on delivery, 0 if guest blocked the MSI, and -1 on error |
|
|
|
Directly inject a MSI message. Only valid with in-kernel irqchip that handles |
|
MSI messages. |
|
|
|
:: |
|
|
|
struct kvm_msi { |
|
__u32 address_lo; |
|
__u32 address_hi; |
|
__u32 data; |
|
__u32 flags; |
|
__u32 devid; |
|
__u8 pad[12]; |
|
}; |
|
|
|
flags: |
|
KVM_MSI_VALID_DEVID: devid contains a valid value. The per-VM |
|
KVM_CAP_MSI_DEVID capability advertises the requirement to provide |
|
the device ID. If this capability is not available, userspace |
|
should never set the KVM_MSI_VALID_DEVID flag as the ioctl might fail. |
|
|
|
If KVM_MSI_VALID_DEVID is set, devid contains a unique device identifier |
|
for the device that wrote the MSI message. For PCI, this is usually a |
|
BFD identifier in the lower 16 bits. |
|
|
|
On x86, address_hi is ignored unless the KVM_X2APIC_API_USE_32BIT_IDS |
|
feature of KVM_CAP_X2APIC_API capability is enabled. If it is enabled, |
|
address_hi bits 31-8 provide bits 31-8 of the destination id. Bits 7-0 of |
|
address_hi must be zero. |
|
|
|
|
|
4.71 KVM_CREATE_PIT2 |
|
-------------------- |
|
|
|
:Capability: KVM_CAP_PIT2 |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_pit_config (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Creates an in-kernel device model for the i8254 PIT. This call is only valid |
|
after enabling in-kernel irqchip support via KVM_CREATE_IRQCHIP. The following |
|
parameters have to be passed:: |
|
|
|
struct kvm_pit_config { |
|
__u32 flags; |
|
__u32 pad[15]; |
|
}; |
|
|
|
Valid flags are:: |
|
|
|
#define KVM_PIT_SPEAKER_DUMMY 1 /* emulate speaker port stub */ |
|
|
|
PIT timer interrupts may use a per-VM kernel thread for injection. If it |
|
exists, this thread will have a name of the following pattern:: |
|
|
|
kvm-pit/<owner-process-pid> |
|
|
|
When running a guest with elevated priorities, the scheduling parameters of |
|
this thread may have to be adjusted accordingly. |
|
|
|
This IOCTL replaces the obsolete KVM_CREATE_PIT. |
|
|
|
|
|
4.72 KVM_GET_PIT2 |
|
----------------- |
|
|
|
:Capability: KVM_CAP_PIT_STATE2 |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_pit_state2 (out) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Retrieves the state of the in-kernel PIT model. Only valid after |
|
KVM_CREATE_PIT2. The state is returned in the following structure:: |
|
|
|
struct kvm_pit_state2 { |
|
struct kvm_pit_channel_state channels[3]; |
|
__u32 flags; |
|
__u32 reserved[9]; |
|
}; |
|
|
|
Valid flags are:: |
|
|
|
/* disable PIT in HPET legacy mode */ |
|
#define KVM_PIT_FLAGS_HPET_LEGACY 0x00000001 |
|
|
|
This IOCTL replaces the obsolete KVM_GET_PIT. |
|
|
|
|
|
4.73 KVM_SET_PIT2 |
|
----------------- |
|
|
|
:Capability: KVM_CAP_PIT_STATE2 |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_pit_state2 (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Sets the state of the in-kernel PIT model. Only valid after KVM_CREATE_PIT2. |
|
See KVM_GET_PIT2 for details on struct kvm_pit_state2. |
|
|
|
This IOCTL replaces the obsolete KVM_SET_PIT. |
|
|
|
|
|
4.74 KVM_PPC_GET_SMMU_INFO |
|
-------------------------- |
|
|
|
:Capability: KVM_CAP_PPC_GET_SMMU_INFO |
|
:Architectures: powerpc |
|
:Type: vm ioctl |
|
:Parameters: None |
|
:Returns: 0 on success, -1 on error |
|
|
|
This populates and returns a structure describing the features of |
|
the "Server" class MMU emulation supported by KVM. |
|
This can in turn be used by userspace to generate the appropriate |
|
device-tree properties for the guest operating system. |
|
|
|
The structure contains some global information, followed by an |
|
array of supported segment page sizes:: |
|
|
|
struct kvm_ppc_smmu_info { |
|
__u64 flags; |
|
__u32 slb_size; |
|
__u32 pad; |
|
struct kvm_ppc_one_seg_page_size sps[KVM_PPC_PAGE_SIZES_MAX_SZ]; |
|
}; |
|
|
|
The supported flags are: |
|
|
|
- KVM_PPC_PAGE_SIZES_REAL: |
|
When that flag is set, guest page sizes must "fit" the backing |
|
store page sizes. When not set, any page size in the list can |
|
be used regardless of how they are backed by userspace. |
|
|
|
- KVM_PPC_1T_SEGMENTS |
|
The emulated MMU supports 1T segments in addition to the |
|
standard 256M ones. |
|
|
|
- KVM_PPC_NO_HASH |
|
This flag indicates that HPT guests are not supported by KVM, |
|
thus all guests must use radix MMU mode. |
|
|
|
The "slb_size" field indicates how many SLB entries are supported |
|
|
|
The "sps" array contains 8 entries indicating the supported base |
|
page sizes for a segment in increasing order. Each entry is defined |
|
as follow:: |
|
|
|
struct kvm_ppc_one_seg_page_size { |
|
__u32 page_shift; /* Base page shift of segment (or 0) */ |
|
__u32 slb_enc; /* SLB encoding for BookS */ |
|
struct kvm_ppc_one_page_size enc[KVM_PPC_PAGE_SIZES_MAX_SZ]; |
|
}; |
|
|
|
An entry with a "page_shift" of 0 is unused. Because the array is |
|
organized in increasing order, a lookup can stop when encoutering |
|
such an entry. |
|
|
|
The "slb_enc" field provides the encoding to use in the SLB for the |
|
page size. The bits are in positions such as the value can directly |
|
be OR'ed into the "vsid" argument of the slbmte instruction. |
|
|
|
The "enc" array is a list which for each of those segment base page |
|
size provides the list of supported actual page sizes (which can be |
|
only larger or equal to the base page size), along with the |
|
corresponding encoding in the hash PTE. Similarly, the array is |
|
8 entries sorted by increasing sizes and an entry with a "0" shift |
|
is an empty entry and a terminator:: |
|
|
|
struct kvm_ppc_one_page_size { |
|
__u32 page_shift; /* Page shift (or 0) */ |
|
__u32 pte_enc; /* Encoding in the HPTE (>>12) */ |
|
}; |
|
|
|
The "pte_enc" field provides a value that can OR'ed into the hash |
|
PTE's RPN field (ie, it needs to be shifted left by 12 to OR it |
|
into the hash PTE second double word). |
|
|
|
4.75 KVM_IRQFD |
|
-------------- |
|
|
|
:Capability: KVM_CAP_IRQFD |
|
:Architectures: x86 s390 arm arm64 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_irqfd (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Allows setting an eventfd to directly trigger a guest interrupt. |
|
kvm_irqfd.fd specifies the file descriptor to use as the eventfd and |
|
kvm_irqfd.gsi specifies the irqchip pin toggled by this event. When |
|
an event is triggered on the eventfd, an interrupt is injected into |
|
the guest using the specified gsi pin. The irqfd is removed using |
|
the KVM_IRQFD_FLAG_DEASSIGN flag, specifying both kvm_irqfd.fd |
|
and kvm_irqfd.gsi. |
|
|
|
With KVM_CAP_IRQFD_RESAMPLE, KVM_IRQFD supports a de-assert and notify |
|
mechanism allowing emulation of level-triggered, irqfd-based |
|
interrupts. When KVM_IRQFD_FLAG_RESAMPLE is set the user must pass an |
|
additional eventfd in the kvm_irqfd.resamplefd field. When operating |
|
in resample mode, posting of an interrupt through kvm_irq.fd asserts |
|
the specified gsi in the irqchip. When the irqchip is resampled, such |
|
as from an EOI, the gsi is de-asserted and the user is notified via |
|
kvm_irqfd.resamplefd. It is the user's responsibility to re-queue |
|
the interrupt if the device making use of it still requires service. |
|
Note that closing the resamplefd is not sufficient to disable the |
|
irqfd. The KVM_IRQFD_FLAG_RESAMPLE is only necessary on assignment |
|
and need not be specified with KVM_IRQFD_FLAG_DEASSIGN. |
|
|
|
On arm/arm64, gsi routing being supported, the following can happen: |
|
|
|
- in case no routing entry is associated to this gsi, injection fails |
|
- in case the gsi is associated to an irqchip routing entry, |
|
irqchip.pin + 32 corresponds to the injected SPI ID. |
|
- in case the gsi is associated to an MSI routing entry, the MSI |
|
message and device ID are translated into an LPI (support restricted |
|
to GICv3 ITS in-kernel emulation). |
|
|
|
4.76 KVM_PPC_ALLOCATE_HTAB |
|
-------------------------- |
|
|
|
:Capability: KVM_CAP_PPC_ALLOC_HTAB |
|
:Architectures: powerpc |
|
:Type: vm ioctl |
|
:Parameters: Pointer to u32 containing hash table order (in/out) |
|
:Returns: 0 on success, -1 on error |
|
|
|
This requests the host kernel to allocate an MMU hash table for a |
|
guest using the PAPR paravirtualization interface. This only does |
|
anything if the kernel is configured to use the Book 3S HV style of |
|
virtualization. Otherwise the capability doesn't exist and the ioctl |
|
returns an ENOTTY error. The rest of this description assumes Book 3S |
|
HV. |
|
|
|
There must be no vcpus running when this ioctl is called; if there |
|
are, it will do nothing and return an EBUSY error. |
|
|
|
The parameter is a pointer to a 32-bit unsigned integer variable |
|
containing the order (log base 2) of the desired size of the hash |
|
table, which must be between 18 and 46. On successful return from the |
|
ioctl, the value will not be changed by the kernel. |
|
|
|
If no hash table has been allocated when any vcpu is asked to run |
|
(with the KVM_RUN ioctl), the host kernel will allocate a |
|
default-sized hash table (16 MB). |
|
|
|
If this ioctl is called when a hash table has already been allocated, |
|
with a different order from the existing hash table, the existing hash |
|
table will be freed and a new one allocated. If this is ioctl is |
|
called when a hash table has already been allocated of the same order |
|
as specified, the kernel will clear out the existing hash table (zero |
|
all HPTEs). In either case, if the guest is using the virtualized |
|
real-mode area (VRMA) facility, the kernel will re-create the VMRA |
|
HPTEs on the next KVM_RUN of any vcpu. |
|
|
|
4.77 KVM_S390_INTERRUPT |
|
----------------------- |
|
|
|
:Capability: basic |
|
:Architectures: s390 |
|
:Type: vm ioctl, vcpu ioctl |
|
:Parameters: struct kvm_s390_interrupt (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Allows to inject an interrupt to the guest. Interrupts can be floating |
|
(vm ioctl) or per cpu (vcpu ioctl), depending on the interrupt type. |
|
|
|
Interrupt parameters are passed via kvm_s390_interrupt:: |
|
|
|
struct kvm_s390_interrupt { |
|
__u32 type; |
|
__u32 parm; |
|
__u64 parm64; |
|
}; |
|
|
|
type can be one of the following: |
|
|
|
KVM_S390_SIGP_STOP (vcpu) |
|
- sigp stop; optional flags in parm |
|
KVM_S390_PROGRAM_INT (vcpu) |
|
- program check; code in parm |
|
KVM_S390_SIGP_SET_PREFIX (vcpu) |
|
- sigp set prefix; prefix address in parm |
|
KVM_S390_RESTART (vcpu) |
|
- restart |
|
KVM_S390_INT_CLOCK_COMP (vcpu) |
|
- clock comparator interrupt |
|
KVM_S390_INT_CPU_TIMER (vcpu) |
|
- CPU timer interrupt |
|
KVM_S390_INT_VIRTIO (vm) |
|
- virtio external interrupt; external interrupt |
|
parameters in parm and parm64 |
|
KVM_S390_INT_SERVICE (vm) |
|
- sclp external interrupt; sclp parameter in parm |
|
KVM_S390_INT_EMERGENCY (vcpu) |
|
- sigp emergency; source cpu in parm |
|
KVM_S390_INT_EXTERNAL_CALL (vcpu) |
|
- sigp external call; source cpu in parm |
|
KVM_S390_INT_IO(ai,cssid,ssid,schid) (vm) |
|
- compound value to indicate an |
|
I/O interrupt (ai - adapter interrupt; cssid,ssid,schid - subchannel); |
|
I/O interruption parameters in parm (subchannel) and parm64 (intparm, |
|
interruption subclass) |
|
KVM_S390_MCHK (vm, vcpu) |
|
- machine check interrupt; cr 14 bits in parm, machine check interrupt |
|
code in parm64 (note that machine checks needing further payload are not |
|
supported by this ioctl) |
|
|
|
This is an asynchronous vcpu ioctl and can be invoked from any thread. |
|
|
|
4.78 KVM_PPC_GET_HTAB_FD |
|
------------------------ |
|
|
|
:Capability: KVM_CAP_PPC_HTAB_FD |
|
:Architectures: powerpc |
|
:Type: vm ioctl |
|
:Parameters: Pointer to struct kvm_get_htab_fd (in) |
|
:Returns: file descriptor number (>= 0) on success, -1 on error |
|
|
|
This returns a file descriptor that can be used either to read out the |
|
entries in the guest's hashed page table (HPT), or to write entries to |
|
initialize the HPT. The returned fd can only be written to if the |
|
KVM_GET_HTAB_WRITE bit is set in the flags field of the argument, and |
|
can only be read if that bit is clear. The argument struct looks like |
|
this:: |
|
|
|
/* For KVM_PPC_GET_HTAB_FD */ |
|
struct kvm_get_htab_fd { |
|
__u64 flags; |
|
__u64 start_index; |
|
__u64 reserved[2]; |
|
}; |
|
|
|
/* Values for kvm_get_htab_fd.flags */ |
|
#define KVM_GET_HTAB_BOLTED_ONLY ((__u64)0x1) |
|
#define KVM_GET_HTAB_WRITE ((__u64)0x2) |
|
|
|
The 'start_index' field gives the index in the HPT of the entry at |
|
which to start reading. It is ignored when writing. |
|
|
|
Reads on the fd will initially supply information about all |
|
"interesting" HPT entries. Interesting entries are those with the |
|
bolted bit set, if the KVM_GET_HTAB_BOLTED_ONLY bit is set, otherwise |
|
all entries. When the end of the HPT is reached, the read() will |
|
return. If read() is called again on the fd, it will start again from |
|
the beginning of the HPT, but will only return HPT entries that have |
|
changed since they were last read. |
|
|
|
Data read or written is structured as a header (8 bytes) followed by a |
|
series of valid HPT entries (16 bytes) each. The header indicates how |
|
many valid HPT entries there are and how many invalid entries follow |
|
the valid entries. The invalid entries are not represented explicitly |
|
in the stream. The header format is:: |
|
|
|
struct kvm_get_htab_header { |
|
__u32 index; |
|
__u16 n_valid; |
|
__u16 n_invalid; |
|
}; |
|
|
|
Writes to the fd create HPT entries starting at the index given in the |
|
header; first 'n_valid' valid entries with contents from the data |
|
written, then 'n_invalid' invalid entries, invalidating any previously |
|
valid entries found. |
|
|
|
4.79 KVM_CREATE_DEVICE |
|
---------------------- |
|
|
|
:Capability: KVM_CAP_DEVICE_CTRL |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_create_device (in/out) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Errors: |
|
|
|
====== ======================================================= |
|
ENODEV The device type is unknown or unsupported |
|
EEXIST Device already created, and this type of device may not |
|
be instantiated multiple times |
|
====== ======================================================= |
|
|
|
Other error conditions may be defined by individual device types or |
|
have their standard meanings. |
|
|
|
Creates an emulated device in the kernel. The file descriptor returned |
|
in fd can be used with KVM_SET/GET/HAS_DEVICE_ATTR. |
|
|
|
If the KVM_CREATE_DEVICE_TEST flag is set, only test whether the |
|
device type is supported (not necessarily whether it can be created |
|
in the current vm). |
|
|
|
Individual devices should not define flags. Attributes should be used |
|
for specifying any behavior that is not implied by the device type |
|
number. |
|
|
|
:: |
|
|
|
struct kvm_create_device { |
|
__u32 type; /* in: KVM_DEV_TYPE_xxx */ |
|
__u32 fd; /* out: device handle */ |
|
__u32 flags; /* in: KVM_CREATE_DEVICE_xxx */ |
|
}; |
|
|
|
4.80 KVM_SET_DEVICE_ATTR/KVM_GET_DEVICE_ATTR |
|
-------------------------------------------- |
|
|
|
:Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device, |
|
KVM_CAP_VCPU_ATTRIBUTES for vcpu device |
|
:Type: device ioctl, vm ioctl, vcpu ioctl |
|
:Parameters: struct kvm_device_attr |
|
:Returns: 0 on success, -1 on error |
|
|
|
Errors: |
|
|
|
===== ============================================================= |
|
ENXIO The group or attribute is unknown/unsupported for this device |
|
or hardware support is missing. |
|
EPERM The attribute cannot (currently) be accessed this way |
|
(e.g. read-only attribute, or attribute that only makes |
|
sense when the device is in a different state) |
|
===== ============================================================= |
|
|
|
Other error conditions may be defined by individual device types. |
|
|
|
Gets/sets a specified piece of device configuration and/or state. The |
|
semantics are device-specific. See individual device documentation in |
|
the "devices" directory. As with ONE_REG, the size of the data |
|
transferred is defined by the particular attribute. |
|
|
|
:: |
|
|
|
struct kvm_device_attr { |
|
__u32 flags; /* no flags currently defined */ |
|
__u32 group; /* device-defined */ |
|
__u64 attr; /* group-defined */ |
|
__u64 addr; /* userspace address of attr data */ |
|
}; |
|
|
|
4.81 KVM_HAS_DEVICE_ATTR |
|
------------------------ |
|
|
|
:Capability: KVM_CAP_DEVICE_CTRL, KVM_CAP_VM_ATTRIBUTES for vm device, |
|
KVM_CAP_VCPU_ATTRIBUTES for vcpu device |
|
:Type: device ioctl, vm ioctl, vcpu ioctl |
|
:Parameters: struct kvm_device_attr |
|
:Returns: 0 on success, -1 on error |
|
|
|
Errors: |
|
|
|
===== ============================================================= |
|
ENXIO The group or attribute is unknown/unsupported for this device |
|
or hardware support is missing. |
|
===== ============================================================= |
|
|
|
Tests whether a device supports a particular attribute. A successful |
|
return indicates the attribute is implemented. It does not necessarily |
|
indicate that the attribute can be read or written in the device's |
|
current state. "addr" is ignored. |
|
|
|
4.82 KVM_ARM_VCPU_INIT |
|
---------------------- |
|
|
|
:Capability: basic |
|
:Architectures: arm, arm64 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_vcpu_init (in) |
|
:Returns: 0 on success; -1 on error |
|
|
|
Errors: |
|
|
|
====== ================================================================= |
|
EINVAL the target is unknown, or the combination of features is invalid. |
|
ENOENT a features bit specified is unknown. |
|
====== ================================================================= |
|
|
|
This tells KVM what type of CPU to present to the guest, and what |
|
optional features it should have. This will cause a reset of the cpu |
|
registers to their initial values. If this is not called, KVM_RUN will |
|
return ENOEXEC for that vcpu. |
|
|
|
The initial values are defined as: |
|
- Processor state: |
|
* AArch64: EL1h, D, A, I and F bits set. All other bits |
|
are cleared. |
|
* AArch32: SVC, A, I and F bits set. All other bits are |
|
cleared. |
|
- General Purpose registers, including PC and SP: set to 0 |
|
- FPSIMD/NEON registers: set to 0 |
|
- SVE registers: set to 0 |
|
- System registers: Reset to their architecturally defined |
|
values as for a warm reset to EL1 (resp. SVC) |
|
|
|
Note that because some registers reflect machine topology, all vcpus |
|
should be created before this ioctl is invoked. |
|
|
|
Userspace can call this function multiple times for a given vcpu, including |
|
after the vcpu has been run. This will reset the vcpu to its initial |
|
state. All calls to this function after the initial call must use the same |
|
target and same set of feature flags, otherwise EINVAL will be returned. |
|
|
|
Possible features: |
|
|
|
- KVM_ARM_VCPU_POWER_OFF: Starts the CPU in a power-off state. |
|
Depends on KVM_CAP_ARM_PSCI. If not set, the CPU will be powered on |
|
and execute guest code when KVM_RUN is called. |
|
- KVM_ARM_VCPU_EL1_32BIT: Starts the CPU in a 32bit mode. |
|
Depends on KVM_CAP_ARM_EL1_32BIT (arm64 only). |
|
- KVM_ARM_VCPU_PSCI_0_2: Emulate PSCI v0.2 (or a future revision |
|
backward compatible with v0.2) for the CPU. |
|
Depends on KVM_CAP_ARM_PSCI_0_2. |
|
- KVM_ARM_VCPU_PMU_V3: Emulate PMUv3 for the CPU. |
|
Depends on KVM_CAP_ARM_PMU_V3. |
|
|
|
- KVM_ARM_VCPU_PTRAUTH_ADDRESS: Enables Address Pointer authentication |
|
for arm64 only. |
|
Depends on KVM_CAP_ARM_PTRAUTH_ADDRESS. |
|
If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are |
|
both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and |
|
KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be |
|
requested. |
|
|
|
- KVM_ARM_VCPU_PTRAUTH_GENERIC: Enables Generic Pointer authentication |
|
for arm64 only. |
|
Depends on KVM_CAP_ARM_PTRAUTH_GENERIC. |
|
If KVM_CAP_ARM_PTRAUTH_ADDRESS and KVM_CAP_ARM_PTRAUTH_GENERIC are |
|
both present, then both KVM_ARM_VCPU_PTRAUTH_ADDRESS and |
|
KVM_ARM_VCPU_PTRAUTH_GENERIC must be requested or neither must be |
|
requested. |
|
|
|
- KVM_ARM_VCPU_SVE: Enables SVE for the CPU (arm64 only). |
|
Depends on KVM_CAP_ARM_SVE. |
|
Requires KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE): |
|
|
|
* After KVM_ARM_VCPU_INIT: |
|
|
|
- KVM_REG_ARM64_SVE_VLS may be read using KVM_GET_ONE_REG: the |
|
initial value of this pseudo-register indicates the best set of |
|
vector lengths possible for a vcpu on this host. |
|
|
|
* Before KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE): |
|
|
|
- KVM_RUN and KVM_GET_REG_LIST are not available; |
|
|
|
- KVM_GET_ONE_REG and KVM_SET_ONE_REG cannot be used to access |
|
the scalable archietctural SVE registers |
|
KVM_REG_ARM64_SVE_ZREG(), KVM_REG_ARM64_SVE_PREG() or |
|
KVM_REG_ARM64_SVE_FFR; |
|
|
|
- KVM_REG_ARM64_SVE_VLS may optionally be written using |
|
KVM_SET_ONE_REG, to modify the set of vector lengths available |
|
for the vcpu. |
|
|
|
* After KVM_ARM_VCPU_FINALIZE(KVM_ARM_VCPU_SVE): |
|
|
|
- the KVM_REG_ARM64_SVE_VLS pseudo-register is immutable, and can |
|
no longer be written using KVM_SET_ONE_REG. |
|
|
|
4.83 KVM_ARM_PREFERRED_TARGET |
|
----------------------------- |
|
|
|
:Capability: basic |
|
:Architectures: arm, arm64 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_vcpu_init (out) |
|
:Returns: 0 on success; -1 on error |
|
|
|
Errors: |
|
|
|
====== ========================================== |
|
ENODEV no preferred target available for the host |
|
====== ========================================== |
|
|
|
This queries KVM for preferred CPU target type which can be emulated |
|
by KVM on underlying host. |
|
|
|
The ioctl returns struct kvm_vcpu_init instance containing information |
|
about preferred CPU target type and recommended features for it. The |
|
kvm_vcpu_init->features bitmap returned will have feature bits set if |
|
the preferred target recommends setting these features, but this is |
|
not mandatory. |
|
|
|
The information returned by this ioctl can be used to prepare an instance |
|
of struct kvm_vcpu_init for KVM_ARM_VCPU_INIT ioctl which will result in |
|
VCPU matching underlying host. |
|
|
|
|
|
4.84 KVM_GET_REG_LIST |
|
--------------------- |
|
|
|
:Capability: basic |
|
:Architectures: arm, arm64, mips |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_reg_list (in/out) |
|
:Returns: 0 on success; -1 on error |
|
|
|
Errors: |
|
|
|
===== ============================================================== |
|
E2BIG the reg index list is too big to fit in the array specified by |
|
the user (the number required will be written into n). |
|
===== ============================================================== |
|
|
|
:: |
|
|
|
struct kvm_reg_list { |
|
__u64 n; /* number of registers in reg[] */ |
|
__u64 reg[0]; |
|
}; |
|
|
|
This ioctl returns the guest registers that are supported for the |
|
KVM_GET_ONE_REG/KVM_SET_ONE_REG calls. |
|
|
|
|
|
4.85 KVM_ARM_SET_DEVICE_ADDR (deprecated) |
|
----------------------------------------- |
|
|
|
:Capability: KVM_CAP_ARM_SET_DEVICE_ADDR |
|
:Architectures: arm, arm64 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_arm_device_address (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Errors: |
|
|
|
====== ============================================ |
|
ENODEV The device id is unknown |
|
ENXIO Device not supported on current system |
|
EEXIST Address already set |
|
E2BIG Address outside guest physical address space |
|
EBUSY Address overlaps with other device range |
|
====== ============================================ |
|
|
|
:: |
|
|
|
struct kvm_arm_device_addr { |
|
__u64 id; |
|
__u64 addr; |
|
}; |
|
|
|
Specify a device address in the guest's physical address space where guests |
|
can access emulated or directly exposed devices, which the host kernel needs |
|
to know about. The id field is an architecture specific identifier for a |
|
specific device. |
|
|
|
ARM/arm64 divides the id field into two parts, a device id and an |
|
address type id specific to the individual device:: |
|
|
|
bits: | 63 ... 32 | 31 ... 16 | 15 ... 0 | |
|
field: | 0x00000000 | device id | addr type id | |
|
|
|
ARM/arm64 currently only require this when using the in-kernel GIC |
|
support for the hardware VGIC features, using KVM_ARM_DEVICE_VGIC_V2 |
|
as the device id. When setting the base address for the guest's |
|
mapping of the VGIC virtual CPU and distributor interface, the ioctl |
|
must be called after calling KVM_CREATE_IRQCHIP, but before calling |
|
KVM_RUN on any of the VCPUs. Calling this ioctl twice for any of the |
|
base addresses will return -EEXIST. |
|
|
|
Note, this IOCTL is deprecated and the more flexible SET/GET_DEVICE_ATTR API |
|
should be used instead. |
|
|
|
|
|
4.86 KVM_PPC_RTAS_DEFINE_TOKEN |
|
------------------------------ |
|
|
|
:Capability: KVM_CAP_PPC_RTAS |
|
:Architectures: ppc |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_rtas_token_args |
|
:Returns: 0 on success, -1 on error |
|
|
|
Defines a token value for a RTAS (Run Time Abstraction Services) |
|
service in order to allow it to be handled in the kernel. The |
|
argument struct gives the name of the service, which must be the name |
|
of a service that has a kernel-side implementation. If the token |
|
value is non-zero, it will be associated with that service, and |
|
subsequent RTAS calls by the guest specifying that token will be |
|
handled by the kernel. If the token value is 0, then any token |
|
associated with the service will be forgotten, and subsequent RTAS |
|
calls by the guest for that service will be passed to userspace to be |
|
handled. |
|
|
|
4.87 KVM_SET_GUEST_DEBUG |
|
------------------------ |
|
|
|
:Capability: KVM_CAP_SET_GUEST_DEBUG |
|
:Architectures: x86, s390, ppc, arm64 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_guest_debug (in) |
|
:Returns: 0 on success; -1 on error |
|
|
|
:: |
|
|
|
struct kvm_guest_debug { |
|
__u32 control; |
|
__u32 pad; |
|
struct kvm_guest_debug_arch arch; |
|
}; |
|
|
|
Set up the processor specific debug registers and configure vcpu for |
|
handling guest debug events. There are two parts to the structure, the |
|
first a control bitfield indicates the type of debug events to handle |
|
when running. Common control bits are: |
|
|
|
- KVM_GUESTDBG_ENABLE: guest debugging is enabled |
|
- KVM_GUESTDBG_SINGLESTEP: the next run should single-step |
|
|
|
The top 16 bits of the control field are architecture specific control |
|
flags which can include the following: |
|
|
|
- KVM_GUESTDBG_USE_SW_BP: using software breakpoints [x86, arm64] |
|
- KVM_GUESTDBG_USE_HW_BP: using hardware breakpoints [x86, s390] |
|
- KVM_GUESTDBG_USE_HW: using hardware debug events [arm64] |
|
- KVM_GUESTDBG_INJECT_DB: inject DB type exception [x86] |
|
- KVM_GUESTDBG_INJECT_BP: inject BP type exception [x86] |
|
- KVM_GUESTDBG_EXIT_PENDING: trigger an immediate guest exit [s390] |
|
|
|
For example KVM_GUESTDBG_USE_SW_BP indicates that software breakpoints |
|
are enabled in memory so we need to ensure breakpoint exceptions are |
|
correctly trapped and the KVM run loop exits at the breakpoint and not |
|
running off into the normal guest vector. For KVM_GUESTDBG_USE_HW_BP |
|
we need to ensure the guest vCPUs architecture specific registers are |
|
updated to the correct (supplied) values. |
|
|
|
The second part of the structure is architecture specific and |
|
typically contains a set of debug registers. |
|
|
|
For arm64 the number of debug registers is implementation defined and |
|
can be determined by querying the KVM_CAP_GUEST_DEBUG_HW_BPS and |
|
KVM_CAP_GUEST_DEBUG_HW_WPS capabilities which return a positive number |
|
indicating the number of supported registers. |
|
|
|
For ppc, the KVM_CAP_PPC_GUEST_DEBUG_SSTEP capability indicates whether |
|
the single-step debug event (KVM_GUESTDBG_SINGLESTEP) is supported. |
|
|
|
Also when supported, KVM_CAP_SET_GUEST_DEBUG2 capability indicates the |
|
supported KVM_GUESTDBG_* bits in the control field. |
|
|
|
When debug events exit the main run loop with the reason |
|
KVM_EXIT_DEBUG with the kvm_debug_exit_arch part of the kvm_run |
|
structure containing architecture specific debug information. |
|
|
|
4.88 KVM_GET_EMULATED_CPUID |
|
--------------------------- |
|
|
|
:Capability: KVM_CAP_EXT_EMUL_CPUID |
|
:Architectures: x86 |
|
:Type: system ioctl |
|
:Parameters: struct kvm_cpuid2 (in/out) |
|
:Returns: 0 on success, -1 on error |
|
|
|
:: |
|
|
|
struct kvm_cpuid2 { |
|
__u32 nent; |
|
__u32 flags; |
|
struct kvm_cpuid_entry2 entries[0]; |
|
}; |
|
|
|
The member 'flags' is used for passing flags from userspace. |
|
|
|
:: |
|
|
|
#define KVM_CPUID_FLAG_SIGNIFCANT_INDEX BIT(0) |
|
#define KVM_CPUID_FLAG_STATEFUL_FUNC BIT(1) /* deprecated */ |
|
#define KVM_CPUID_FLAG_STATE_READ_NEXT BIT(2) /* deprecated */ |
|
|
|
struct kvm_cpuid_entry2 { |
|
__u32 function; |
|
__u32 index; |
|
__u32 flags; |
|
__u32 eax; |
|
__u32 ebx; |
|
__u32 ecx; |
|
__u32 edx; |
|
__u32 padding[3]; |
|
}; |
|
|
|
This ioctl returns x86 cpuid features which are emulated by |
|
kvm.Userspace can use the information returned by this ioctl to query |
|
which features are emulated by kvm instead of being present natively. |
|
|
|
Userspace invokes KVM_GET_EMULATED_CPUID by passing a kvm_cpuid2 |
|
structure with the 'nent' field indicating the number of entries in |
|
the variable-size array 'entries'. If the number of entries is too low |
|
to describe the cpu capabilities, an error (E2BIG) is returned. If the |
|
number is too high, the 'nent' field is adjusted and an error (ENOMEM) |
|
is returned. If the number is just right, the 'nent' field is adjusted |
|
to the number of valid entries in the 'entries' array, which is then |
|
filled. |
|
|
|
The entries returned are the set CPUID bits of the respective features |
|
which kvm emulates, as returned by the CPUID instruction, with unknown |
|
or unsupported feature bits cleared. |
|
|
|
Features like x2apic, for example, may not be present in the host cpu |
|
but are exposed by kvm in KVM_GET_SUPPORTED_CPUID because they can be |
|
emulated efficiently and thus not included here. |
|
|
|
The fields in each entry are defined as follows: |
|
|
|
function: |
|
the eax value used to obtain the entry |
|
index: |
|
the ecx value used to obtain the entry (for entries that are |
|
affected by ecx) |
|
flags: |
|
an OR of zero or more of the following: |
|
|
|
KVM_CPUID_FLAG_SIGNIFCANT_INDEX: |
|
if the index field is valid |
|
|
|
eax, ebx, ecx, edx: |
|
|
|
the values returned by the cpuid instruction for |
|
this function/index combination |
|
|
|
4.89 KVM_S390_MEM_OP |
|
-------------------- |
|
|
|
:Capability: KVM_CAP_S390_MEM_OP |
|
:Architectures: s390 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_s390_mem_op (in) |
|
:Returns: = 0 on success, |
|
< 0 on generic error (e.g. -EFAULT or -ENOMEM), |
|
> 0 if an exception occurred while walking the page tables |
|
|
|
Read or write data from/to the logical (virtual) memory of a VCPU. |
|
|
|
Parameters are specified via the following structure:: |
|
|
|
struct kvm_s390_mem_op { |
|
__u64 gaddr; /* the guest address */ |
|
__u64 flags; /* flags */ |
|
__u32 size; /* amount of bytes */ |
|
__u32 op; /* type of operation */ |
|
__u64 buf; /* buffer in userspace */ |
|
__u8 ar; /* the access register number */ |
|
__u8 reserved[31]; /* should be set to 0 */ |
|
}; |
|
|
|
The type of operation is specified in the "op" field. It is either |
|
KVM_S390_MEMOP_LOGICAL_READ for reading from logical memory space or |
|
KVM_S390_MEMOP_LOGICAL_WRITE for writing to logical memory space. The |
|
KVM_S390_MEMOP_F_CHECK_ONLY flag can be set in the "flags" field to check |
|
whether the corresponding memory access would create an access exception |
|
(without touching the data in the memory at the destination). In case an |
|
access exception occurred while walking the MMU tables of the guest, the |
|
ioctl returns a positive error number to indicate the type of exception. |
|
This exception is also raised directly at the corresponding VCPU if the |
|
flag KVM_S390_MEMOP_F_INJECT_EXCEPTION is set in the "flags" field. |
|
|
|
The start address of the memory region has to be specified in the "gaddr" |
|
field, and the length of the region in the "size" field (which must not |
|
be 0). The maximum value for "size" can be obtained by checking the |
|
KVM_CAP_S390_MEM_OP capability. "buf" is the buffer supplied by the |
|
userspace application where the read data should be written to for |
|
KVM_S390_MEMOP_LOGICAL_READ, or where the data that should be written is |
|
stored for a KVM_S390_MEMOP_LOGICAL_WRITE. When KVM_S390_MEMOP_F_CHECK_ONLY |
|
is specified, "buf" is unused and can be NULL. "ar" designates the access |
|
register number to be used; the valid range is 0..15. |
|
|
|
The "reserved" field is meant for future extensions. It is not used by |
|
KVM with the currently defined set of flags. |
|
|
|
4.90 KVM_S390_GET_SKEYS |
|
----------------------- |
|
|
|
:Capability: KVM_CAP_S390_SKEYS |
|
:Architectures: s390 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_s390_skeys |
|
:Returns: 0 on success, KVM_S390_GET_KEYS_NONE if guest is not using storage |
|
keys, negative value on error |
|
|
|
This ioctl is used to get guest storage key values on the s390 |
|
architecture. The ioctl takes parameters via the kvm_s390_skeys struct:: |
|
|
|
struct kvm_s390_skeys { |
|
__u64 start_gfn; |
|
__u64 count; |
|
__u64 skeydata_addr; |
|
__u32 flags; |
|
__u32 reserved[9]; |
|
}; |
|
|
|
The start_gfn field is the number of the first guest frame whose storage keys |
|
you want to get. |
|
|
|
The count field is the number of consecutive frames (starting from start_gfn) |
|
whose storage keys to get. The count field must be at least 1 and the maximum |
|
allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range |
|
will cause the ioctl to return -EINVAL. |
|
|
|
The skeydata_addr field is the address to a buffer large enough to hold count |
|
bytes. This buffer will be filled with storage key data by the ioctl. |
|
|
|
4.91 KVM_S390_SET_SKEYS |
|
----------------------- |
|
|
|
:Capability: KVM_CAP_S390_SKEYS |
|
:Architectures: s390 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_s390_skeys |
|
:Returns: 0 on success, negative value on error |
|
|
|
This ioctl is used to set guest storage key values on the s390 |
|
architecture. The ioctl takes parameters via the kvm_s390_skeys struct. |
|
See section on KVM_S390_GET_SKEYS for struct definition. |
|
|
|
The start_gfn field is the number of the first guest frame whose storage keys |
|
you want to set. |
|
|
|
The count field is the number of consecutive frames (starting from start_gfn) |
|
whose storage keys to get. The count field must be at least 1 and the maximum |
|
allowed value is defined as KVM_S390_SKEYS_ALLOC_MAX. Values outside this range |
|
will cause the ioctl to return -EINVAL. |
|
|
|
The skeydata_addr field is the address to a buffer containing count bytes of |
|
storage keys. Each byte in the buffer will be set as the storage key for a |
|
single frame starting at start_gfn for count frames. |
|
|
|
Note: If any architecturally invalid key value is found in the given data then |
|
the ioctl will return -EINVAL. |
|
|
|
4.92 KVM_S390_IRQ |
|
----------------- |
|
|
|
:Capability: KVM_CAP_S390_INJECT_IRQ |
|
:Architectures: s390 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_s390_irq (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Errors: |
|
|
|
|
|
====== ================================================================= |
|
EINVAL interrupt type is invalid |
|
type is KVM_S390_SIGP_STOP and flag parameter is invalid value, |
|
type is KVM_S390_INT_EXTERNAL_CALL and code is bigger |
|
than the maximum of VCPUs |
|
EBUSY type is KVM_S390_SIGP_SET_PREFIX and vcpu is not stopped, |
|
type is KVM_S390_SIGP_STOP and a stop irq is already pending, |
|
type is KVM_S390_INT_EXTERNAL_CALL and an external call interrupt |
|
is already pending |
|
====== ================================================================= |
|
|
|
Allows to inject an interrupt to the guest. |
|
|
|
Using struct kvm_s390_irq as a parameter allows |
|
to inject additional payload which is not |
|
possible via KVM_S390_INTERRUPT. |
|
|
|
Interrupt parameters are passed via kvm_s390_irq:: |
|
|
|
struct kvm_s390_irq { |
|
__u64 type; |
|
union { |
|
struct kvm_s390_io_info io; |
|
struct kvm_s390_ext_info ext; |
|
struct kvm_s390_pgm_info pgm; |
|
struct kvm_s390_emerg_info emerg; |
|
struct kvm_s390_extcall_info extcall; |
|
struct kvm_s390_prefix_info prefix; |
|
struct kvm_s390_stop_info stop; |
|
struct kvm_s390_mchk_info mchk; |
|
char reserved[64]; |
|
} u; |
|
}; |
|
|
|
type can be one of the following: |
|
|
|
- KVM_S390_SIGP_STOP - sigp stop; parameter in .stop |
|
- KVM_S390_PROGRAM_INT - program check; parameters in .pgm |
|
- KVM_S390_SIGP_SET_PREFIX - sigp set prefix; parameters in .prefix |
|
- KVM_S390_RESTART - restart; no parameters |
|
- KVM_S390_INT_CLOCK_COMP - clock comparator interrupt; no parameters |
|
- KVM_S390_INT_CPU_TIMER - CPU timer interrupt; no parameters |
|
- KVM_S390_INT_EMERGENCY - sigp emergency; parameters in .emerg |
|
- KVM_S390_INT_EXTERNAL_CALL - sigp external call; parameters in .extcall |
|
- KVM_S390_MCHK - machine check interrupt; parameters in .mchk |
|
|
|
This is an asynchronous vcpu ioctl and can be invoked from any thread. |
|
|
|
4.94 KVM_S390_GET_IRQ_STATE |
|
--------------------------- |
|
|
|
:Capability: KVM_CAP_S390_IRQ_STATE |
|
:Architectures: s390 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_s390_irq_state (out) |
|
:Returns: >= number of bytes copied into buffer, |
|
-EINVAL if buffer size is 0, |
|
-ENOBUFS if buffer size is too small to fit all pending interrupts, |
|
-EFAULT if the buffer address was invalid |
|
|
|
This ioctl allows userspace to retrieve the complete state of all currently |
|
pending interrupts in a single buffer. Use cases include migration |
|
and introspection. The parameter structure contains the address of a |
|
userspace buffer and its length:: |
|
|
|
struct kvm_s390_irq_state { |
|
__u64 buf; |
|
__u32 flags; /* will stay unused for compatibility reasons */ |
|
__u32 len; |
|
__u32 reserved[4]; /* will stay unused for compatibility reasons */ |
|
}; |
|
|
|
Userspace passes in the above struct and for each pending interrupt a |
|
struct kvm_s390_irq is copied to the provided buffer. |
|
|
|
The structure contains a flags and a reserved field for future extensions. As |
|
the kernel never checked for flags == 0 and QEMU never pre-zeroed flags and |
|
reserved, these fields can not be used in the future without breaking |
|
compatibility. |
|
|
|
If -ENOBUFS is returned the buffer provided was too small and userspace |
|
may retry with a bigger buffer. |
|
|
|
4.95 KVM_S390_SET_IRQ_STATE |
|
--------------------------- |
|
|
|
:Capability: KVM_CAP_S390_IRQ_STATE |
|
:Architectures: s390 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_s390_irq_state (in) |
|
:Returns: 0 on success, |
|
-EFAULT if the buffer address was invalid, |
|
-EINVAL for an invalid buffer length (see below), |
|
-EBUSY if there were already interrupts pending, |
|
errors occurring when actually injecting the |
|
interrupt. See KVM_S390_IRQ. |
|
|
|
This ioctl allows userspace to set the complete state of all cpu-local |
|
interrupts currently pending for the vcpu. It is intended for restoring |
|
interrupt state after a migration. The input parameter is a userspace buffer |
|
containing a struct kvm_s390_irq_state:: |
|
|
|
struct kvm_s390_irq_state { |
|
__u64 buf; |
|
__u32 flags; /* will stay unused for compatibility reasons */ |
|
__u32 len; |
|
__u32 reserved[4]; /* will stay unused for compatibility reasons */ |
|
}; |
|
|
|
The restrictions for flags and reserved apply as well. |
|
(see KVM_S390_GET_IRQ_STATE) |
|
|
|
The userspace memory referenced by buf contains a struct kvm_s390_irq |
|
for each interrupt to be injected into the guest. |
|
If one of the interrupts could not be injected for some reason the |
|
ioctl aborts. |
|
|
|
len must be a multiple of sizeof(struct kvm_s390_irq). It must be > 0 |
|
and it must not exceed (max_vcpus + 32) * sizeof(struct kvm_s390_irq), |
|
which is the maximum number of possibly pending cpu-local interrupts. |
|
|
|
4.96 KVM_SMI |
|
------------ |
|
|
|
:Capability: KVM_CAP_X86_SMM |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: none |
|
:Returns: 0 on success, -1 on error |
|
|
|
Queues an SMI on the thread's vcpu. |
|
|
|
4.97 KVM_X86_SET_MSR_FILTER |
|
---------------------------- |
|
|
|
:Capability: KVM_X86_SET_MSR_FILTER |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_msr_filter |
|
:Returns: 0 on success, < 0 on error |
|
|
|
:: |
|
|
|
struct kvm_msr_filter_range { |
|
#define KVM_MSR_FILTER_READ (1 << 0) |
|
#define KVM_MSR_FILTER_WRITE (1 << 1) |
|
__u32 flags; |
|
__u32 nmsrs; /* number of msrs in bitmap */ |
|
__u32 base; /* MSR index the bitmap starts at */ |
|
__u8 *bitmap; /* a 1 bit allows the operations in flags, 0 denies */ |
|
}; |
|
|
|
#define KVM_MSR_FILTER_MAX_RANGES 16 |
|
struct kvm_msr_filter { |
|
#define KVM_MSR_FILTER_DEFAULT_ALLOW (0 << 0) |
|
#define KVM_MSR_FILTER_DEFAULT_DENY (1 << 0) |
|
__u32 flags; |
|
struct kvm_msr_filter_range ranges[KVM_MSR_FILTER_MAX_RANGES]; |
|
}; |
|
|
|
flags values for ``struct kvm_msr_filter_range``: |
|
|
|
``KVM_MSR_FILTER_READ`` |
|
|
|
Filter read accesses to MSRs using the given bitmap. A 0 in the bitmap |
|
indicates that a read should immediately fail, while a 1 indicates that |
|
a read for a particular MSR should be handled regardless of the default |
|
filter action. |
|
|
|
``KVM_MSR_FILTER_WRITE`` |
|
|
|
Filter write accesses to MSRs using the given bitmap. A 0 in the bitmap |
|
indicates that a write should immediately fail, while a 1 indicates that |
|
a write for a particular MSR should be handled regardless of the default |
|
filter action. |
|
|
|
``KVM_MSR_FILTER_READ | KVM_MSR_FILTER_WRITE`` |
|
|
|
Filter both read and write accesses to MSRs using the given bitmap. A 0 |
|
in the bitmap indicates that both reads and writes should immediately fail, |
|
while a 1 indicates that reads and writes for a particular MSR are not |
|
filtered by this range. |
|
|
|
flags values for ``struct kvm_msr_filter``: |
|
|
|
``KVM_MSR_FILTER_DEFAULT_ALLOW`` |
|
|
|
If no filter range matches an MSR index that is getting accessed, KVM will |
|
fall back to allowing access to the MSR. |
|
|
|
``KVM_MSR_FILTER_DEFAULT_DENY`` |
|
|
|
If no filter range matches an MSR index that is getting accessed, KVM will |
|
fall back to rejecting access to the MSR. In this mode, all MSRs that should |
|
be processed by KVM need to explicitly be marked as allowed in the bitmaps. |
|
|
|
This ioctl allows user space to define up to 16 bitmaps of MSR ranges to |
|
specify whether a certain MSR access should be explicitly filtered for or not. |
|
|
|
If this ioctl has never been invoked, MSR accesses are not guarded and the |
|
default KVM in-kernel emulation behavior is fully preserved. |
|
|
|
Calling this ioctl with an empty set of ranges (all nmsrs == 0) disables MSR |
|
filtering. In that mode, ``KVM_MSR_FILTER_DEFAULT_DENY`` is invalid and causes |
|
an error. |
|
|
|
As soon as the filtering is in place, every MSR access is processed through |
|
the filtering except for accesses to the x2APIC MSRs (from 0x800 to 0x8ff); |
|
x2APIC MSRs are always allowed, independent of the ``default_allow`` setting, |
|
and their behavior depends on the ``X2APIC_ENABLE`` bit of the APIC base |
|
register. |
|
|
|
If a bit is within one of the defined ranges, read and write accesses are |
|
guarded by the bitmap's value for the MSR index if the kind of access |
|
is included in the ``struct kvm_msr_filter_range`` flags. If no range |
|
cover this particular access, the behavior is determined by the flags |
|
field in the kvm_msr_filter struct: ``KVM_MSR_FILTER_DEFAULT_ALLOW`` |
|
and ``KVM_MSR_FILTER_DEFAULT_DENY``. |
|
|
|
Each bitmap range specifies a range of MSRs to potentially allow access on. |
|
The range goes from MSR index [base .. base+nmsrs]. The flags field |
|
indicates whether reads, writes or both reads and writes are filtered |
|
by setting a 1 bit in the bitmap for the corresponding MSR index. |
|
|
|
If an MSR access is not permitted through the filtering, it generates a |
|
#GP inside the guest. When combined with KVM_CAP_X86_USER_SPACE_MSR, that |
|
allows user space to deflect and potentially handle various MSR accesses |
|
into user space. |
|
|
|
If a vCPU is in running state while this ioctl is invoked, the vCPU may |
|
experience inconsistent filtering behavior on MSR accesses. |
|
|
|
4.98 KVM_CREATE_SPAPR_TCE_64 |
|
---------------------------- |
|
|
|
:Capability: KVM_CAP_SPAPR_TCE_64 |
|
:Architectures: powerpc |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_create_spapr_tce_64 (in) |
|
:Returns: file descriptor for manipulating the created TCE table |
|
|
|
This is an extension for KVM_CAP_SPAPR_TCE which only supports 32bit |
|
windows, described in 4.62 KVM_CREATE_SPAPR_TCE |
|
|
|
This capability uses extended struct in ioctl interface:: |
|
|
|
/* for KVM_CAP_SPAPR_TCE_64 */ |
|
struct kvm_create_spapr_tce_64 { |
|
__u64 liobn; |
|
__u32 page_shift; |
|
__u32 flags; |
|
__u64 offset; /* in pages */ |
|
__u64 size; /* in pages */ |
|
}; |
|
|
|
The aim of extension is to support an additional bigger DMA window with |
|
a variable page size. |
|
KVM_CREATE_SPAPR_TCE_64 receives a 64bit window size, an IOMMU page shift and |
|
a bus offset of the corresponding DMA window, @size and @offset are numbers |
|
of IOMMU pages. |
|
|
|
@flags are not used at the moment. |
|
|
|
The rest of functionality is identical to KVM_CREATE_SPAPR_TCE. |
|
|
|
4.99 KVM_REINJECT_CONTROL |
|
------------------------- |
|
|
|
:Capability: KVM_CAP_REINJECT_CONTROL |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_reinject_control (in) |
|
:Returns: 0 on success, |
|
-EFAULT if struct kvm_reinject_control cannot be read, |
|
-ENXIO if KVM_CREATE_PIT or KVM_CREATE_PIT2 didn't succeed earlier. |
|
|
|
i8254 (PIT) has two modes, reinject and !reinject. The default is reinject, |
|
where KVM queues elapsed i8254 ticks and monitors completion of interrupt from |
|
vector(s) that i8254 injects. Reinject mode dequeues a tick and injects its |
|
interrupt whenever there isn't a pending interrupt from i8254. |
|
!reinject mode injects an interrupt as soon as a tick arrives. |
|
|
|
:: |
|
|
|
struct kvm_reinject_control { |
|
__u8 pit_reinject; |
|
__u8 reserved[31]; |
|
}; |
|
|
|
pit_reinject = 0 (!reinject mode) is recommended, unless running an old |
|
operating system that uses the PIT for timing (e.g. Linux 2.4.x). |
|
|
|
4.100 KVM_PPC_CONFIGURE_V3_MMU |
|
------------------------------ |
|
|
|
:Capability: KVM_CAP_PPC_RADIX_MMU or KVM_CAP_PPC_HASH_MMU_V3 |
|
:Architectures: ppc |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_ppc_mmuv3_cfg (in) |
|
:Returns: 0 on success, |
|
-EFAULT if struct kvm_ppc_mmuv3_cfg cannot be read, |
|
-EINVAL if the configuration is invalid |
|
|
|
This ioctl controls whether the guest will use radix or HPT (hashed |
|
page table) translation, and sets the pointer to the process table for |
|
the guest. |
|
|
|
:: |
|
|
|
struct kvm_ppc_mmuv3_cfg { |
|
__u64 flags; |
|
__u64 process_table; |
|
}; |
|
|
|
There are two bits that can be set in flags; KVM_PPC_MMUV3_RADIX and |
|
KVM_PPC_MMUV3_GTSE. KVM_PPC_MMUV3_RADIX, if set, configures the guest |
|
to use radix tree translation, and if clear, to use HPT translation. |
|
KVM_PPC_MMUV3_GTSE, if set and if KVM permits it, configures the guest |
|
to be able to use the global TLB and SLB invalidation instructions; |
|
if clear, the guest may not use these instructions. |
|
|
|
The process_table field specifies the address and size of the guest |
|
process table, which is in the guest's space. This field is formatted |
|
as the second doubleword of the partition table entry, as defined in |
|
the Power ISA V3.00, Book III section 5.7.6.1. |
|
|
|
4.101 KVM_PPC_GET_RMMU_INFO |
|
--------------------------- |
|
|
|
:Capability: KVM_CAP_PPC_RADIX_MMU |
|
:Architectures: ppc |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_ppc_rmmu_info (out) |
|
:Returns: 0 on success, |
|
-EFAULT if struct kvm_ppc_rmmu_info cannot be written, |
|
-EINVAL if no useful information can be returned |
|
|
|
This ioctl returns a structure containing two things: (a) a list |
|
containing supported radix tree geometries, and (b) a list that maps |
|
page sizes to put in the "AP" (actual page size) field for the tlbie |
|
(TLB invalidate entry) instruction. |
|
|
|
:: |
|
|
|
struct kvm_ppc_rmmu_info { |
|
struct kvm_ppc_radix_geom { |
|
__u8 page_shift; |
|
__u8 level_bits[4]; |
|
__u8 pad[3]; |
|
} geometries[8]; |
|
__u32 ap_encodings[8]; |
|
}; |
|
|
|
The geometries[] field gives up to 8 supported geometries for the |
|
radix page table, in terms of the log base 2 of the smallest page |
|
size, and the number of bits indexed at each level of the tree, from |
|
the PTE level up to the PGD level in that order. Any unused entries |
|
will have 0 in the page_shift field. |
|
|
|
The ap_encodings gives the supported page sizes and their AP field |
|
encodings, encoded with the AP value in the top 3 bits and the log |
|
base 2 of the page size in the bottom 6 bits. |
|
|
|
4.102 KVM_PPC_RESIZE_HPT_PREPARE |
|
-------------------------------- |
|
|
|
:Capability: KVM_CAP_SPAPR_RESIZE_HPT |
|
:Architectures: powerpc |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_ppc_resize_hpt (in) |
|
:Returns: 0 on successful completion, |
|
>0 if a new HPT is being prepared, the value is an estimated |
|
number of milliseconds until preparation is complete, |
|
-EFAULT if struct kvm_reinject_control cannot be read, |
|
-EINVAL if the supplied shift or flags are invalid, |
|
-ENOMEM if unable to allocate the new HPT, |
|
|
|
Used to implement the PAPR extension for runtime resizing of a guest's |
|
Hashed Page Table (HPT). Specifically this starts, stops or monitors |
|
the preparation of a new potential HPT for the guest, essentially |
|
implementing the H_RESIZE_HPT_PREPARE hypercall. |
|
|
|
:: |
|
|
|
struct kvm_ppc_resize_hpt { |
|
__u64 flags; |
|
__u32 shift; |
|
__u32 pad; |
|
}; |
|
|
|
If called with shift > 0 when there is no pending HPT for the guest, |
|
this begins preparation of a new pending HPT of size 2^(shift) bytes. |
|
It then returns a positive integer with the estimated number of |
|
milliseconds until preparation is complete. |
|
|
|
If called when there is a pending HPT whose size does not match that |
|
requested in the parameters, discards the existing pending HPT and |
|
creates a new one as above. |
|
|
|
If called when there is a pending HPT of the size requested, will: |
|
|
|
* If preparation of the pending HPT is already complete, return 0 |
|
* If preparation of the pending HPT has failed, return an error |
|
code, then discard the pending HPT. |
|
* If preparation of the pending HPT is still in progress, return an |
|
estimated number of milliseconds until preparation is complete. |
|
|
|
If called with shift == 0, discards any currently pending HPT and |
|
returns 0 (i.e. cancels any in-progress preparation). |
|
|
|
flags is reserved for future expansion, currently setting any bits in |
|
flags will result in an -EINVAL. |
|
|
|
Normally this will be called repeatedly with the same parameters until |
|
it returns <= 0. The first call will initiate preparation, subsequent |
|
ones will monitor preparation until it completes or fails. |
|
|
|
4.103 KVM_PPC_RESIZE_HPT_COMMIT |
|
------------------------------- |
|
|
|
:Capability: KVM_CAP_SPAPR_RESIZE_HPT |
|
:Architectures: powerpc |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_ppc_resize_hpt (in) |
|
:Returns: 0 on successful completion, |
|
-EFAULT if struct kvm_reinject_control cannot be read, |
|
-EINVAL if the supplied shift or flags are invalid, |
|
-ENXIO is there is no pending HPT, or the pending HPT doesn't |
|
have the requested size, |
|
-EBUSY if the pending HPT is not fully prepared, |
|
-ENOSPC if there was a hash collision when moving existing |
|
HPT entries to the new HPT, |
|
-EIO on other error conditions |
|
|
|
Used to implement the PAPR extension for runtime resizing of a guest's |
|
Hashed Page Table (HPT). Specifically this requests that the guest be |
|
transferred to working with the new HPT, essentially implementing the |
|
H_RESIZE_HPT_COMMIT hypercall. |
|
|
|
:: |
|
|
|
struct kvm_ppc_resize_hpt { |
|
__u64 flags; |
|
__u32 shift; |
|
__u32 pad; |
|
}; |
|
|
|
This should only be called after KVM_PPC_RESIZE_HPT_PREPARE has |
|
returned 0 with the same parameters. In other cases |
|
KVM_PPC_RESIZE_HPT_COMMIT will return an error (usually -ENXIO or |
|
-EBUSY, though others may be possible if the preparation was started, |
|
but failed). |
|
|
|
This will have undefined effects on the guest if it has not already |
|
placed itself in a quiescent state where no vcpu will make MMU enabled |
|
memory accesses. |
|
|
|
On succsful completion, the pending HPT will become the guest's active |
|
HPT and the previous HPT will be discarded. |
|
|
|
On failure, the guest will still be operating on its previous HPT. |
|
|
|
4.104 KVM_X86_GET_MCE_CAP_SUPPORTED |
|
----------------------------------- |
|
|
|
:Capability: KVM_CAP_MCE |
|
:Architectures: x86 |
|
:Type: system ioctl |
|
:Parameters: u64 mce_cap (out) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Returns supported MCE capabilities. The u64 mce_cap parameter |
|
has the same format as the MSR_IA32_MCG_CAP register. Supported |
|
capabilities will have the corresponding bits set. |
|
|
|
4.105 KVM_X86_SETUP_MCE |
|
----------------------- |
|
|
|
:Capability: KVM_CAP_MCE |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: u64 mcg_cap (in) |
|
:Returns: 0 on success, |
|
-EFAULT if u64 mcg_cap cannot be read, |
|
-EINVAL if the requested number of banks is invalid, |
|
-EINVAL if requested MCE capability is not supported. |
|
|
|
Initializes MCE support for use. The u64 mcg_cap parameter |
|
has the same format as the MSR_IA32_MCG_CAP register and |
|
specifies which capabilities should be enabled. The maximum |
|
supported number of error-reporting banks can be retrieved when |
|
checking for KVM_CAP_MCE. The supported capabilities can be |
|
retrieved with KVM_X86_GET_MCE_CAP_SUPPORTED. |
|
|
|
4.106 KVM_X86_SET_MCE |
|
--------------------- |
|
|
|
:Capability: KVM_CAP_MCE |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_x86_mce (in) |
|
:Returns: 0 on success, |
|
-EFAULT if struct kvm_x86_mce cannot be read, |
|
-EINVAL if the bank number is invalid, |
|
-EINVAL if VAL bit is not set in status field. |
|
|
|
Inject a machine check error (MCE) into the guest. The input |
|
parameter is:: |
|
|
|
struct kvm_x86_mce { |
|
__u64 status; |
|
__u64 addr; |
|
__u64 misc; |
|
__u64 mcg_status; |
|
__u8 bank; |
|
__u8 pad1[7]; |
|
__u64 pad2[3]; |
|
}; |
|
|
|
If the MCE being reported is an uncorrected error, KVM will |
|
inject it as an MCE exception into the guest. If the guest |
|
MCG_STATUS register reports that an MCE is in progress, KVM |
|
causes an KVM_EXIT_SHUTDOWN vmexit. |
|
|
|
Otherwise, if the MCE is a corrected error, KVM will just |
|
store it in the corresponding bank (provided this bank is |
|
not holding a previously reported uncorrected error). |
|
|
|
4.107 KVM_S390_GET_CMMA_BITS |
|
---------------------------- |
|
|
|
:Capability: KVM_CAP_S390_CMMA_MIGRATION |
|
:Architectures: s390 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_s390_cmma_log (in, out) |
|
:Returns: 0 on success, a negative value on error |
|
|
|
This ioctl is used to get the values of the CMMA bits on the s390 |
|
architecture. It is meant to be used in two scenarios: |
|
|
|
- During live migration to save the CMMA values. Live migration needs |
|
to be enabled via the KVM_REQ_START_MIGRATION VM property. |
|
- To non-destructively peek at the CMMA values, with the flag |
|
KVM_S390_CMMA_PEEK set. |
|
|
|
The ioctl takes parameters via the kvm_s390_cmma_log struct. The desired |
|
values are written to a buffer whose location is indicated via the "values" |
|
member in the kvm_s390_cmma_log struct. The values in the input struct are |
|
also updated as needed. |
|
|
|
Each CMMA value takes up one byte. |
|
|
|
:: |
|
|
|
struct kvm_s390_cmma_log { |
|
__u64 start_gfn; |
|
__u32 count; |
|
__u32 flags; |
|
union { |
|
__u64 remaining; |
|
__u64 mask; |
|
}; |
|
__u64 values; |
|
}; |
|
|
|
start_gfn is the number of the first guest frame whose CMMA values are |
|
to be retrieved, |
|
|
|
count is the length of the buffer in bytes, |
|
|
|
values points to the buffer where the result will be written to. |
|
|
|
If count is greater than KVM_S390_SKEYS_MAX, then it is considered to be |
|
KVM_S390_SKEYS_MAX. KVM_S390_SKEYS_MAX is re-used for consistency with |
|
other ioctls. |
|
|
|
The result is written in the buffer pointed to by the field values, and |
|
the values of the input parameter are updated as follows. |
|
|
|
Depending on the flags, different actions are performed. The only |
|
supported flag so far is KVM_S390_CMMA_PEEK. |
|
|
|
The default behaviour if KVM_S390_CMMA_PEEK is not set is: |
|
start_gfn will indicate the first page frame whose CMMA bits were dirty. |
|
It is not necessarily the same as the one passed as input, as clean pages |
|
are skipped. |
|
|
|
count will indicate the number of bytes actually written in the buffer. |
|
It can (and very often will) be smaller than the input value, since the |
|
buffer is only filled until 16 bytes of clean values are found (which |
|
are then not copied in the buffer). Since a CMMA migration block needs |
|
the base address and the length, for a total of 16 bytes, we will send |
|
back some clean data if there is some dirty data afterwards, as long as |
|
the size of the clean data does not exceed the size of the header. This |
|
allows to minimize the amount of data to be saved or transferred over |
|
the network at the expense of more roundtrips to userspace. The next |
|
invocation of the ioctl will skip over all the clean values, saving |
|
potentially more than just the 16 bytes we found. |
|
|
|
If KVM_S390_CMMA_PEEK is set: |
|
the existing storage attributes are read even when not in migration |
|
mode, and no other action is performed; |
|
|
|
the output start_gfn will be equal to the input start_gfn, |
|
|
|
the output count will be equal to the input count, except if the end of |
|
memory has been reached. |
|
|
|
In both cases: |
|
the field "remaining" will indicate the total number of dirty CMMA values |
|
still remaining, or 0 if KVM_S390_CMMA_PEEK is set and migration mode is |
|
not enabled. |
|
|
|
mask is unused. |
|
|
|
values points to the userspace buffer where the result will be stored. |
|
|
|
This ioctl can fail with -ENOMEM if not enough memory can be allocated to |
|
complete the task, with -ENXIO if CMMA is not enabled, with -EINVAL if |
|
KVM_S390_CMMA_PEEK is not set but migration mode was not enabled, with |
|
-EFAULT if the userspace address is invalid or if no page table is |
|
present for the addresses (e.g. when using hugepages). |
|
|
|
4.108 KVM_S390_SET_CMMA_BITS |
|
---------------------------- |
|
|
|
:Capability: KVM_CAP_S390_CMMA_MIGRATION |
|
:Architectures: s390 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_s390_cmma_log (in) |
|
:Returns: 0 on success, a negative value on error |
|
|
|
This ioctl is used to set the values of the CMMA bits on the s390 |
|
architecture. It is meant to be used during live migration to restore |
|
the CMMA values, but there are no restrictions on its use. |
|
The ioctl takes parameters via the kvm_s390_cmma_values struct. |
|
Each CMMA value takes up one byte. |
|
|
|
:: |
|
|
|
struct kvm_s390_cmma_log { |
|
__u64 start_gfn; |
|
__u32 count; |
|
__u32 flags; |
|
union { |
|
__u64 remaining; |
|
__u64 mask; |
|
}; |
|
__u64 values; |
|
}; |
|
|
|
start_gfn indicates the starting guest frame number, |
|
|
|
count indicates how many values are to be considered in the buffer, |
|
|
|
flags is not used and must be 0. |
|
|
|
mask indicates which PGSTE bits are to be considered. |
|
|
|
remaining is not used. |
|
|
|
values points to the buffer in userspace where to store the values. |
|
|
|
This ioctl can fail with -ENOMEM if not enough memory can be allocated to |
|
complete the task, with -ENXIO if CMMA is not enabled, with -EINVAL if |
|
the count field is too large (e.g. more than KVM_S390_CMMA_SIZE_MAX) or |
|
if the flags field was not 0, with -EFAULT if the userspace address is |
|
invalid, if invalid pages are written to (e.g. after the end of memory) |
|
or if no page table is present for the addresses (e.g. when using |
|
hugepages). |
|
|
|
4.109 KVM_PPC_GET_CPU_CHAR |
|
-------------------------- |
|
|
|
:Capability: KVM_CAP_PPC_GET_CPU_CHAR |
|
:Architectures: powerpc |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_ppc_cpu_char (out) |
|
:Returns: 0 on successful completion, |
|
-EFAULT if struct kvm_ppc_cpu_char cannot be written |
|
|
|
This ioctl gives userspace information about certain characteristics |
|
of the CPU relating to speculative execution of instructions and |
|
possible information leakage resulting from speculative execution (see |
|
CVE-2017-5715, CVE-2017-5753 and CVE-2017-5754). The information is |
|
returned in struct kvm_ppc_cpu_char, which looks like this:: |
|
|
|
struct kvm_ppc_cpu_char { |
|
__u64 character; /* characteristics of the CPU */ |
|
__u64 behaviour; /* recommended software behaviour */ |
|
__u64 character_mask; /* valid bits in character */ |
|
__u64 behaviour_mask; /* valid bits in behaviour */ |
|
}; |
|
|
|
For extensibility, the character_mask and behaviour_mask fields |
|
indicate which bits of character and behaviour have been filled in by |
|
the kernel. If the set of defined bits is extended in future then |
|
userspace will be able to tell whether it is running on a kernel that |
|
knows about the new bits. |
|
|
|
The character field describes attributes of the CPU which can help |
|
with preventing inadvertent information disclosure - specifically, |
|
whether there is an instruction to flash-invalidate the L1 data cache |
|
(ori 30,30,0 or mtspr SPRN_TRIG2,rN), whether the L1 data cache is set |
|
to a mode where entries can only be used by the thread that created |
|
them, whether the bcctr[l] instruction prevents speculation, and |
|
whether a speculation barrier instruction (ori 31,31,0) is provided. |
|
|
|
The behaviour field describes actions that software should take to |
|
prevent inadvertent information disclosure, and thus describes which |
|
vulnerabilities the hardware is subject to; specifically whether the |
|
L1 data cache should be flushed when returning to user mode from the |
|
kernel, and whether a speculation barrier should be placed between an |
|
array bounds check and the array access. |
|
|
|
These fields use the same bit definitions as the new |
|
H_GET_CPU_CHARACTERISTICS hypercall. |
|
|
|
4.110 KVM_MEMORY_ENCRYPT_OP |
|
--------------------------- |
|
|
|
:Capability: basic |
|
:Architectures: x86 |
|
:Type: vm |
|
:Parameters: an opaque platform specific structure (in/out) |
|
:Returns: 0 on success; -1 on error |
|
|
|
If the platform supports creating encrypted VMs then this ioctl can be used |
|
for issuing platform-specific memory encryption commands to manage those |
|
encrypted VMs. |
|
|
|
Currently, this ioctl is used for issuing Secure Encrypted Virtualization |
|
(SEV) commands on AMD Processors. The SEV commands are defined in |
|
Documentation/virt/kvm/amd-memory-encryption.rst. |
|
|
|
4.111 KVM_MEMORY_ENCRYPT_REG_REGION |
|
----------------------------------- |
|
|
|
:Capability: basic |
|
:Architectures: x86 |
|
:Type: system |
|
:Parameters: struct kvm_enc_region (in) |
|
:Returns: 0 on success; -1 on error |
|
|
|
This ioctl can be used to register a guest memory region which may |
|
contain encrypted data (e.g. guest RAM, SMRAM etc). |
|
|
|
It is used in the SEV-enabled guest. When encryption is enabled, a guest |
|
memory region may contain encrypted data. The SEV memory encryption |
|
engine uses a tweak such that two identical plaintext pages, each at |
|
different locations will have differing ciphertexts. So swapping or |
|
moving ciphertext of those pages will not result in plaintext being |
|
swapped. So relocating (or migrating) physical backing pages for the SEV |
|
guest will require some additional steps. |
|
|
|
Note: The current SEV key management spec does not provide commands to |
|
swap or migrate (move) ciphertext pages. Hence, for now we pin the guest |
|
memory region registered with the ioctl. |
|
|
|
4.112 KVM_MEMORY_ENCRYPT_UNREG_REGION |
|
------------------------------------- |
|
|
|
:Capability: basic |
|
:Architectures: x86 |
|
:Type: system |
|
:Parameters: struct kvm_enc_region (in) |
|
:Returns: 0 on success; -1 on error |
|
|
|
This ioctl can be used to unregister the guest memory region registered |
|
with KVM_MEMORY_ENCRYPT_REG_REGION ioctl above. |
|
|
|
4.113 KVM_HYPERV_EVENTFD |
|
------------------------ |
|
|
|
:Capability: KVM_CAP_HYPERV_EVENTFD |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_hyperv_eventfd (in) |
|
|
|
This ioctl (un)registers an eventfd to receive notifications from the guest on |
|
the specified Hyper-V connection id through the SIGNAL_EVENT hypercall, without |
|
causing a user exit. SIGNAL_EVENT hypercall with non-zero event flag number |
|
(bits 24-31) still triggers a KVM_EXIT_HYPERV_HCALL user exit. |
|
|
|
:: |
|
|
|
struct kvm_hyperv_eventfd { |
|
__u32 conn_id; |
|
__s32 fd; |
|
__u32 flags; |
|
__u32 padding[3]; |
|
}; |
|
|
|
The conn_id field should fit within 24 bits:: |
|
|
|
#define KVM_HYPERV_CONN_ID_MASK 0x00ffffff |
|
|
|
The acceptable values for the flags field are:: |
|
|
|
#define KVM_HYPERV_EVENTFD_DEASSIGN (1 << 0) |
|
|
|
:Returns: 0 on success, |
|
-EINVAL if conn_id or flags is outside the allowed range, |
|
-ENOENT on deassign if the conn_id isn't registered, |
|
-EEXIST on assign if the conn_id is already registered |
|
|
|
4.114 KVM_GET_NESTED_STATE |
|
-------------------------- |
|
|
|
:Capability: KVM_CAP_NESTED_STATE |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_nested_state (in/out) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Errors: |
|
|
|
===== ============================================================= |
|
E2BIG the total state size exceeds the value of 'size' specified by |
|
the user; the size required will be written into size. |
|
===== ============================================================= |
|
|
|
:: |
|
|
|
struct kvm_nested_state { |
|
__u16 flags; |
|
__u16 format; |
|
__u32 size; |
|
|
|
union { |
|
struct kvm_vmx_nested_state_hdr vmx; |
|
struct kvm_svm_nested_state_hdr svm; |
|
|
|
/* Pad the header to 128 bytes. */ |
|
__u8 pad[120]; |
|
} hdr; |
|
|
|
union { |
|
struct kvm_vmx_nested_state_data vmx[0]; |
|
struct kvm_svm_nested_state_data svm[0]; |
|
} data; |
|
}; |
|
|
|
#define KVM_STATE_NESTED_GUEST_MODE 0x00000001 |
|
#define KVM_STATE_NESTED_RUN_PENDING 0x00000002 |
|
#define KVM_STATE_NESTED_EVMCS 0x00000004 |
|
|
|
#define KVM_STATE_NESTED_FORMAT_VMX 0 |
|
#define KVM_STATE_NESTED_FORMAT_SVM 1 |
|
|
|
#define KVM_STATE_NESTED_VMX_VMCS_SIZE 0x1000 |
|
|
|
#define KVM_STATE_NESTED_VMX_SMM_GUEST_MODE 0x00000001 |
|
#define KVM_STATE_NESTED_VMX_SMM_VMXON 0x00000002 |
|
|
|
#define KVM_STATE_VMX_PREEMPTION_TIMER_DEADLINE 0x00000001 |
|
|
|
struct kvm_vmx_nested_state_hdr { |
|
__u64 vmxon_pa; |
|
__u64 vmcs12_pa; |
|
|
|
struct { |
|
__u16 flags; |
|
} smm; |
|
|
|
__u32 flags; |
|
__u64 preemption_timer_deadline; |
|
}; |
|
|
|
struct kvm_vmx_nested_state_data { |
|
__u8 vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; |
|
__u8 shadow_vmcs12[KVM_STATE_NESTED_VMX_VMCS_SIZE]; |
|
}; |
|
|
|
This ioctl copies the vcpu's nested virtualization state from the kernel to |
|
userspace. |
|
|
|
The maximum size of the state can be retrieved by passing KVM_CAP_NESTED_STATE |
|
to the KVM_CHECK_EXTENSION ioctl(). |
|
|
|
4.115 KVM_SET_NESTED_STATE |
|
-------------------------- |
|
|
|
:Capability: KVM_CAP_NESTED_STATE |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_nested_state (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
This copies the vcpu's kvm_nested_state struct from userspace to the kernel. |
|
For the definition of struct kvm_nested_state, see KVM_GET_NESTED_STATE. |
|
|
|
4.116 KVM_(UN)REGISTER_COALESCED_MMIO |
|
------------------------------------- |
|
|
|
:Capability: KVM_CAP_COALESCED_MMIO (for coalesced mmio) |
|
KVM_CAP_COALESCED_PIO (for coalesced pio) |
|
:Architectures: all |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_coalesced_mmio_zone |
|
:Returns: 0 on success, < 0 on error |
|
|
|
Coalesced I/O is a performance optimization that defers hardware |
|
register write emulation so that userspace exits are avoided. It is |
|
typically used to reduce the overhead of emulating frequently accessed |
|
hardware registers. |
|
|
|
When a hardware register is configured for coalesced I/O, write accesses |
|
do not exit to userspace and their value is recorded in a ring buffer |
|
that is shared between kernel and userspace. |
|
|
|
Coalesced I/O is used if one or more write accesses to a hardware |
|
register can be deferred until a read or a write to another hardware |
|
register on the same device. This last access will cause a vmexit and |
|
userspace will process accesses from the ring buffer before emulating |
|
it. That will avoid exiting to userspace on repeated writes. |
|
|
|
Coalesced pio is based on coalesced mmio. There is little difference |
|
between coalesced mmio and pio except that coalesced pio records accesses |
|
to I/O ports. |
|
|
|
4.117 KVM_CLEAR_DIRTY_LOG (vm ioctl) |
|
------------------------------------ |
|
|
|
:Capability: KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 |
|
:Architectures: x86, arm, arm64, mips |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_clear_dirty_log (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
:: |
|
|
|
/* for KVM_CLEAR_DIRTY_LOG */ |
|
struct kvm_clear_dirty_log { |
|
__u32 slot; |
|
__u32 num_pages; |
|
__u64 first_page; |
|
union { |
|
void __user *dirty_bitmap; /* one bit per page */ |
|
__u64 padding; |
|
}; |
|
}; |
|
|
|
The ioctl clears the dirty status of pages in a memory slot, according to |
|
the bitmap that is passed in struct kvm_clear_dirty_log's dirty_bitmap |
|
field. Bit 0 of the bitmap corresponds to page "first_page" in the |
|
memory slot, and num_pages is the size in bits of the input bitmap. |
|
first_page must be a multiple of 64; num_pages must also be a multiple of |
|
64 unless first_page + num_pages is the size of the memory slot. For each |
|
bit that is set in the input bitmap, the corresponding page is marked "clean" |
|
in KVM's dirty bitmap, and dirty tracking is re-enabled for that page |
|
(for example via write-protection, or by clearing the dirty bit in |
|
a page table entry). |
|
|
|
If KVM_CAP_MULTI_ADDRESS_SPACE is available, bits 16-31 of slot field specifies |
|
the address space for which you want to clear the dirty status. See |
|
KVM_SET_USER_MEMORY_REGION for details on the usage of slot field. |
|
|
|
This ioctl is mostly useful when KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 |
|
is enabled; for more information, see the description of the capability. |
|
However, it can always be used as long as KVM_CHECK_EXTENSION confirms |
|
that KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 is present. |
|
|
|
4.118 KVM_GET_SUPPORTED_HV_CPUID |
|
-------------------------------- |
|
|
|
:Capability: KVM_CAP_HYPERV_CPUID (vcpu), KVM_CAP_SYS_HYPERV_CPUID (system) |
|
:Architectures: x86 |
|
:Type: system ioctl, vcpu ioctl |
|
:Parameters: struct kvm_cpuid2 (in/out) |
|
:Returns: 0 on success, -1 on error |
|
|
|
:: |
|
|
|
struct kvm_cpuid2 { |
|
__u32 nent; |
|
__u32 padding; |
|
struct kvm_cpuid_entry2 entries[0]; |
|
}; |
|
|
|
struct kvm_cpuid_entry2 { |
|
__u32 function; |
|
__u32 index; |
|
__u32 flags; |
|
__u32 eax; |
|
__u32 ebx; |
|
__u32 ecx; |
|
__u32 edx; |
|
__u32 padding[3]; |
|
}; |
|
|
|
This ioctl returns x86 cpuid features leaves related to Hyper-V emulation in |
|
KVM. Userspace can use the information returned by this ioctl to construct |
|
cpuid information presented to guests consuming Hyper-V enlightenments (e.g. |
|
Windows or Hyper-V guests). |
|
|
|
CPUID feature leaves returned by this ioctl are defined by Hyper-V Top Level |
|
Functional Specification (TLFS). These leaves can't be obtained with |
|
KVM_GET_SUPPORTED_CPUID ioctl because some of them intersect with KVM feature |
|
leaves (0x40000000, 0x40000001). |
|
|
|
Currently, the following list of CPUID leaves are returned: |
|
|
|
- HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS |
|
- HYPERV_CPUID_INTERFACE |
|
- HYPERV_CPUID_VERSION |
|
- HYPERV_CPUID_FEATURES |
|
- HYPERV_CPUID_ENLIGHTMENT_INFO |
|
- HYPERV_CPUID_IMPLEMENT_LIMITS |
|
- HYPERV_CPUID_NESTED_FEATURES |
|
- HYPERV_CPUID_SYNDBG_VENDOR_AND_MAX_FUNCTIONS |
|
- HYPERV_CPUID_SYNDBG_INTERFACE |
|
- HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES |
|
|
|
Userspace invokes KVM_GET_SUPPORTED_HV_CPUID by passing a kvm_cpuid2 structure |
|
with the 'nent' field indicating the number of entries in the variable-size |
|
array 'entries'. If the number of entries is too low to describe all Hyper-V |
|
feature leaves, an error (E2BIG) is returned. If the number is more or equal |
|
to the number of Hyper-V feature leaves, the 'nent' field is adjusted to the |
|
number of valid entries in the 'entries' array, which is then filled. |
|
|
|
'index' and 'flags' fields in 'struct kvm_cpuid_entry2' are currently reserved, |
|
userspace should not expect to get any particular value there. |
|
|
|
Note, vcpu version of KVM_GET_SUPPORTED_HV_CPUID is currently deprecated. Unlike |
|
system ioctl which exposes all supported feature bits unconditionally, vcpu |
|
version has the following quirks: |
|
|
|
- HYPERV_CPUID_NESTED_FEATURES leaf and HV_X64_ENLIGHTENED_VMCS_RECOMMENDED |
|
feature bit are only exposed when Enlightened VMCS was previously enabled |
|
on the corresponding vCPU (KVM_CAP_HYPERV_ENLIGHTENED_VMCS). |
|
- HV_STIMER_DIRECT_MODE_AVAILABLE bit is only exposed with in-kernel LAPIC. |
|
(presumes KVM_CREATE_IRQCHIP has already been called). |
|
|
|
4.119 KVM_ARM_VCPU_FINALIZE |
|
--------------------------- |
|
|
|
:Architectures: arm, arm64 |
|
:Type: vcpu ioctl |
|
:Parameters: int feature (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Errors: |
|
|
|
====== ============================================================== |
|
EPERM feature not enabled, needs configuration, or already finalized |
|
EINVAL feature unknown or not present |
|
====== ============================================================== |
|
|
|
Recognised values for feature: |
|
|
|
===== =========================================== |
|
arm64 KVM_ARM_VCPU_SVE (requires KVM_CAP_ARM_SVE) |
|
===== =========================================== |
|
|
|
Finalizes the configuration of the specified vcpu feature. |
|
|
|
The vcpu must already have been initialised, enabling the affected feature, by |
|
means of a successful KVM_ARM_VCPU_INIT call with the appropriate flag set in |
|
features[]. |
|
|
|
For affected vcpu features, this is a mandatory step that must be performed |
|
before the vcpu is fully usable. |
|
|
|
Between KVM_ARM_VCPU_INIT and KVM_ARM_VCPU_FINALIZE, the feature may be |
|
configured by use of ioctls such as KVM_SET_ONE_REG. The exact configuration |
|
that should be performaned and how to do it are feature-dependent. |
|
|
|
Other calls that depend on a particular feature being finalized, such as |
|
KVM_RUN, KVM_GET_REG_LIST, KVM_GET_ONE_REG and KVM_SET_ONE_REG, will fail with |
|
-EPERM unless the feature has already been finalized by means of a |
|
KVM_ARM_VCPU_FINALIZE call. |
|
|
|
See KVM_ARM_VCPU_INIT for details of vcpu features that require finalization |
|
using this ioctl. |
|
|
|
4.120 KVM_SET_PMU_EVENT_FILTER |
|
------------------------------ |
|
|
|
:Capability: KVM_CAP_PMU_EVENT_FILTER |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_pmu_event_filter (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
:: |
|
|
|
struct kvm_pmu_event_filter { |
|
__u32 action; |
|
__u32 nevents; |
|
__u32 fixed_counter_bitmap; |
|
__u32 flags; |
|
__u32 pad[4]; |
|
__u64 events[0]; |
|
}; |
|
|
|
This ioctl restricts the set of PMU events that the guest can program. |
|
The argument holds a list of events which will be allowed or denied. |
|
The eventsel+umask of each event the guest attempts to program is compared |
|
against the events field to determine whether the guest should have access. |
|
The events field only controls general purpose counters; fixed purpose |
|
counters are controlled by the fixed_counter_bitmap. |
|
|
|
No flags are defined yet, the field must be zero. |
|
|
|
Valid values for 'action':: |
|
|
|
#define KVM_PMU_EVENT_ALLOW 0 |
|
#define KVM_PMU_EVENT_DENY 1 |
|
|
|
4.121 KVM_PPC_SVM_OFF |
|
--------------------- |
|
|
|
:Capability: basic |
|
:Architectures: powerpc |
|
:Type: vm ioctl |
|
:Parameters: none |
|
:Returns: 0 on successful completion, |
|
|
|
Errors: |
|
|
|
====== ================================================================ |
|
EINVAL if ultravisor failed to terminate the secure guest |
|
ENOMEM if hypervisor failed to allocate new radix page tables for guest |
|
====== ================================================================ |
|
|
|
This ioctl is used to turn off the secure mode of the guest or transition |
|
the guest from secure mode to normal mode. This is invoked when the guest |
|
is reset. This has no effect if called for a normal guest. |
|
|
|
This ioctl issues an ultravisor call to terminate the secure guest, |
|
unpins the VPA pages and releases all the device pages that are used to |
|
track the secure pages by hypervisor. |
|
|
|
4.122 KVM_S390_NORMAL_RESET |
|
--------------------------- |
|
|
|
:Capability: KVM_CAP_S390_VCPU_RESETS |
|
:Architectures: s390 |
|
:Type: vcpu ioctl |
|
:Parameters: none |
|
:Returns: 0 |
|
|
|
This ioctl resets VCPU registers and control structures according to |
|
the cpu reset definition in the POP (Principles Of Operation). |
|
|
|
4.123 KVM_S390_INITIAL_RESET |
|
---------------------------- |
|
|
|
:Capability: none |
|
:Architectures: s390 |
|
:Type: vcpu ioctl |
|
:Parameters: none |
|
:Returns: 0 |
|
|
|
This ioctl resets VCPU registers and control structures according to |
|
the initial cpu reset definition in the POP. However, the cpu is not |
|
put into ESA mode. This reset is a superset of the normal reset. |
|
|
|
4.124 KVM_S390_CLEAR_RESET |
|
-------------------------- |
|
|
|
:Capability: KVM_CAP_S390_VCPU_RESETS |
|
:Architectures: s390 |
|
:Type: vcpu ioctl |
|
:Parameters: none |
|
:Returns: 0 |
|
|
|
This ioctl resets VCPU registers and control structures according to |
|
the clear cpu reset definition in the POP. However, the cpu is not put |
|
into ESA mode. This reset is a superset of the initial reset. |
|
|
|
|
|
4.125 KVM_S390_PV_COMMAND |
|
------------------------- |
|
|
|
:Capability: KVM_CAP_S390_PROTECTED |
|
:Architectures: s390 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_pv_cmd |
|
:Returns: 0 on success, < 0 on error |
|
|
|
:: |
|
|
|
struct kvm_pv_cmd { |
|
__u32 cmd; /* Command to be executed */ |
|
__u16 rc; /* Ultravisor return code */ |
|
__u16 rrc; /* Ultravisor return reason code */ |
|
__u64 data; /* Data or address */ |
|
__u32 flags; /* flags for future extensions. Must be 0 for now */ |
|
__u32 reserved[3]; |
|
}; |
|
|
|
cmd values: |
|
|
|
KVM_PV_ENABLE |
|
Allocate memory and register the VM with the Ultravisor, thereby |
|
donating memory to the Ultravisor that will become inaccessible to |
|
KVM. All existing CPUs are converted to protected ones. After this |
|
command has succeeded, any CPU added via hotplug will become |
|
protected during its creation as well. |
|
|
|
Errors: |
|
|
|
===== ============================= |
|
EINTR an unmasked signal is pending |
|
===== ============================= |
|
|
|
KVM_PV_DISABLE |
|
|
|
Deregister the VM from the Ultravisor and reclaim the memory that |
|
had been donated to the Ultravisor, making it usable by the kernel |
|
again. All registered VCPUs are converted back to non-protected |
|
ones. |
|
|
|
KVM_PV_VM_SET_SEC_PARMS |
|
Pass the image header from VM memory to the Ultravisor in |
|
preparation of image unpacking and verification. |
|
|
|
KVM_PV_VM_UNPACK |
|
Unpack (protect and decrypt) a page of the encrypted boot image. |
|
|
|
KVM_PV_VM_VERIFY |
|
Verify the integrity of the unpacked image. Only if this succeeds, |
|
KVM is allowed to start protected VCPUs. |
|
|
|
4.126 KVM_X86_SET_MSR_FILTER |
|
---------------------------- |
|
|
|
:Capability: KVM_CAP_X86_MSR_FILTER |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_msr_filter |
|
:Returns: 0 on success, < 0 on error |
|
|
|
:: |
|
|
|
struct kvm_msr_filter_range { |
|
#define KVM_MSR_FILTER_READ (1 << 0) |
|
#define KVM_MSR_FILTER_WRITE (1 << 1) |
|
__u32 flags; |
|
__u32 nmsrs; /* number of msrs in bitmap */ |
|
__u32 base; /* MSR index the bitmap starts at */ |
|
__u8 *bitmap; /* a 1 bit allows the operations in flags, 0 denies */ |
|
}; |
|
|
|
#define KVM_MSR_FILTER_MAX_RANGES 16 |
|
struct kvm_msr_filter { |
|
#define KVM_MSR_FILTER_DEFAULT_ALLOW (0 << 0) |
|
#define KVM_MSR_FILTER_DEFAULT_DENY (1 << 0) |
|
__u32 flags; |
|
struct kvm_msr_filter_range ranges[KVM_MSR_FILTER_MAX_RANGES]; |
|
}; |
|
|
|
flags values for ``struct kvm_msr_filter_range``: |
|
|
|
``KVM_MSR_FILTER_READ`` |
|
|
|
Filter read accesses to MSRs using the given bitmap. A 0 in the bitmap |
|
indicates that a read should immediately fail, while a 1 indicates that |
|
a read for a particular MSR should be handled regardless of the default |
|
filter action. |
|
|
|
``KVM_MSR_FILTER_WRITE`` |
|
|
|
Filter write accesses to MSRs using the given bitmap. A 0 in the bitmap |
|
indicates that a write should immediately fail, while a 1 indicates that |
|
a write for a particular MSR should be handled regardless of the default |
|
filter action. |
|
|
|
``KVM_MSR_FILTER_READ | KVM_MSR_FILTER_WRITE`` |
|
|
|
Filter both read and write accesses to MSRs using the given bitmap. A 0 |
|
in the bitmap indicates that both reads and writes should immediately fail, |
|
while a 1 indicates that reads and writes for a particular MSR are not |
|
filtered by this range. |
|
|
|
flags values for ``struct kvm_msr_filter``: |
|
|
|
``KVM_MSR_FILTER_DEFAULT_ALLOW`` |
|
|
|
If no filter range matches an MSR index that is getting accessed, KVM will |
|
fall back to allowing access to the MSR. |
|
|
|
``KVM_MSR_FILTER_DEFAULT_DENY`` |
|
|
|
If no filter range matches an MSR index that is getting accessed, KVM will |
|
fall back to rejecting access to the MSR. In this mode, all MSRs that should |
|
be processed by KVM need to explicitly be marked as allowed in the bitmaps. |
|
|
|
This ioctl allows user space to define up to 16 bitmaps of MSR ranges to |
|
specify whether a certain MSR access should be explicitly filtered for or not. |
|
|
|
If this ioctl has never been invoked, MSR accesses are not guarded and the |
|
default KVM in-kernel emulation behavior is fully preserved. |
|
|
|
Calling this ioctl with an empty set of ranges (all nmsrs == 0) disables MSR |
|
filtering. In that mode, ``KVM_MSR_FILTER_DEFAULT_DENY`` is invalid and causes |
|
an error. |
|
|
|
As soon as the filtering is in place, every MSR access is processed through |
|
the filtering except for accesses to the x2APIC MSRs (from 0x800 to 0x8ff); |
|
x2APIC MSRs are always allowed, independent of the ``default_allow`` setting, |
|
and their behavior depends on the ``X2APIC_ENABLE`` bit of the APIC base |
|
register. |
|
|
|
If a bit is within one of the defined ranges, read and write accesses are |
|
guarded by the bitmap's value for the MSR index if the kind of access |
|
is included in the ``struct kvm_msr_filter_range`` flags. If no range |
|
cover this particular access, the behavior is determined by the flags |
|
field in the kvm_msr_filter struct: ``KVM_MSR_FILTER_DEFAULT_ALLOW`` |
|
and ``KVM_MSR_FILTER_DEFAULT_DENY``. |
|
|
|
Each bitmap range specifies a range of MSRs to potentially allow access on. |
|
The range goes from MSR index [base .. base+nmsrs]. The flags field |
|
indicates whether reads, writes or both reads and writes are filtered |
|
by setting a 1 bit in the bitmap for the corresponding MSR index. |
|
|
|
If an MSR access is not permitted through the filtering, it generates a |
|
#GP inside the guest. When combined with KVM_CAP_X86_USER_SPACE_MSR, that |
|
allows user space to deflect and potentially handle various MSR accesses |
|
into user space. |
|
|
|
Note, invoking this ioctl with a vCPU is running is inherently racy. However, |
|
KVM does guarantee that vCPUs will see either the previous filter or the new |
|
filter, e.g. MSRs with identical settings in both the old and new filter will |
|
have deterministic behavior. |
|
|
|
4.127 KVM_XEN_HVM_SET_ATTR |
|
-------------------------- |
|
|
|
:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_xen_hvm_attr |
|
:Returns: 0 on success, < 0 on error |
|
|
|
:: |
|
|
|
struct kvm_xen_hvm_attr { |
|
__u16 type; |
|
__u16 pad[3]; |
|
union { |
|
__u8 long_mode; |
|
__u8 vector; |
|
struct { |
|
__u64 gfn; |
|
} shared_info; |
|
__u64 pad[4]; |
|
} u; |
|
}; |
|
|
|
type values: |
|
|
|
KVM_XEN_ATTR_TYPE_LONG_MODE |
|
Sets the ABI mode of the VM to 32-bit or 64-bit (long mode). This |
|
determines the layout of the shared info pages exposed to the VM. |
|
|
|
KVM_XEN_ATTR_TYPE_SHARED_INFO |
|
Sets the guest physical frame number at which the Xen "shared info" |
|
page resides. Note that although Xen places vcpu_info for the first |
|
32 vCPUs in the shared_info page, KVM does not automatically do so |
|
and instead requires that KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO be used |
|
explicitly even when the vcpu_info for a given vCPU resides at the |
|
"default" location in the shared_info page. This is because KVM is |
|
not aware of the Xen CPU id which is used as the index into the |
|
vcpu_info[] array, so cannot know the correct default location. |
|
|
|
KVM_XEN_ATTR_TYPE_UPCALL_VECTOR |
|
Sets the exception vector used to deliver Xen event channel upcalls. |
|
|
|
4.127 KVM_XEN_HVM_GET_ATTR |
|
-------------------------- |
|
|
|
:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO |
|
:Architectures: x86 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_xen_hvm_attr |
|
:Returns: 0 on success, < 0 on error |
|
|
|
Allows Xen VM attributes to be read. For the structure and types, |
|
see KVM_XEN_HVM_SET_ATTR above. |
|
|
|
4.128 KVM_XEN_VCPU_SET_ATTR |
|
--------------------------- |
|
|
|
:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_xen_vcpu_attr |
|
:Returns: 0 on success, < 0 on error |
|
|
|
:: |
|
|
|
struct kvm_xen_vcpu_attr { |
|
__u16 type; |
|
__u16 pad[3]; |
|
union { |
|
__u64 gpa; |
|
__u64 pad[4]; |
|
struct { |
|
__u64 state; |
|
__u64 state_entry_time; |
|
__u64 time_running; |
|
__u64 time_runnable; |
|
__u64 time_blocked; |
|
__u64 time_offline; |
|
} runstate; |
|
} u; |
|
}; |
|
|
|
type values: |
|
|
|
KVM_XEN_VCPU_ATTR_TYPE_VCPU_INFO |
|
Sets the guest physical address of the vcpu_info for a given vCPU. |
|
|
|
KVM_XEN_VCPU_ATTR_TYPE_VCPU_TIME_INFO |
|
Sets the guest physical address of an additional pvclock structure |
|
for a given vCPU. This is typically used for guest vsyscall support. |
|
|
|
KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR |
|
Sets the guest physical address of the vcpu_runstate_info for a given |
|
vCPU. This is how a Xen guest tracks CPU state such as steal time. |
|
|
|
KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_CURRENT |
|
Sets the runstate (RUNSTATE_running/_runnable/_blocked/_offline) of |
|
the given vCPU from the .u.runstate.state member of the structure. |
|
KVM automatically accounts running and runnable time but blocked |
|
and offline states are only entered explicitly. |
|
|
|
KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_DATA |
|
Sets all fields of the vCPU runstate data from the .u.runstate member |
|
of the structure, including the current runstate. The state_entry_time |
|
must equal the sum of the other four times. |
|
|
|
KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST |
|
This *adds* the contents of the .u.runstate members of the structure |
|
to the corresponding members of the given vCPU's runstate data, thus |
|
permitting atomic adjustments to the runstate times. The adjustment |
|
to the state_entry_time must equal the sum of the adjustments to the |
|
other four times. The state field must be set to -1, or to a valid |
|
runstate value (RUNSTATE_running, RUNSTATE_runnable, RUNSTATE_blocked |
|
or RUNSTATE_offline) to set the current accounted state as of the |
|
adjusted state_entry_time. |
|
|
|
4.129 KVM_XEN_VCPU_GET_ATTR |
|
--------------------------- |
|
|
|
:Capability: KVM_CAP_XEN_HVM / KVM_XEN_HVM_CONFIG_SHARED_INFO |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_xen_vcpu_attr |
|
:Returns: 0 on success, < 0 on error |
|
|
|
Allows Xen vCPU attributes to be read. For the structure and types, |
|
see KVM_XEN_VCPU_SET_ATTR above. |
|
|
|
The KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADJUST type may not be used |
|
with the KVM_XEN_VCPU_GET_ATTR ioctl. |
|
|
|
4.130 KVM_ARM_MTE_COPY_TAGS |
|
--------------------------- |
|
|
|
:Capability: KVM_CAP_ARM_MTE |
|
:Architectures: arm64 |
|
:Type: vm ioctl |
|
:Parameters: struct kvm_arm_copy_mte_tags |
|
:Returns: number of bytes copied, < 0 on error (-EINVAL for incorrect |
|
arguments, -EFAULT if memory cannot be accessed). |
|
|
|
:: |
|
|
|
struct kvm_arm_copy_mte_tags { |
|
__u64 guest_ipa; |
|
__u64 length; |
|
void __user *addr; |
|
__u64 flags; |
|
__u64 reserved[2]; |
|
}; |
|
|
|
Copies Memory Tagging Extension (MTE) tags to/from guest tag memory. The |
|
``guest_ipa`` and ``length`` fields must be ``PAGE_SIZE`` aligned. The ``addr`` |
|
field must point to a buffer which the tags will be copied to or from. |
|
|
|
``flags`` specifies the direction of copy, either ``KVM_ARM_TAGS_TO_GUEST`` or |
|
``KVM_ARM_TAGS_FROM_GUEST``. |
|
|
|
The size of the buffer to store the tags is ``(length / 16)`` bytes |
|
(granules in MTE are 16 bytes long). Each byte contains a single tag |
|
value. This matches the format of ``PTRACE_PEEKMTETAGS`` and |
|
``PTRACE_POKEMTETAGS``. |
|
|
|
If an error occurs before any data is copied then a negative error code is |
|
returned. If some tags have been copied before an error occurs then the number |
|
of bytes successfully copied is returned. If the call completes successfully |
|
then ``length`` is returned. |
|
|
|
4.131 KVM_GET_SREGS2 |
|
------------------ |
|
|
|
:Capability: KVM_CAP_SREGS2 |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_sregs2 (out) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Reads special registers from the vcpu. |
|
This ioctl (when supported) replaces the KVM_GET_SREGS. |
|
|
|
:: |
|
|
|
struct kvm_sregs2 { |
|
/* out (KVM_GET_SREGS2) / in (KVM_SET_SREGS2) */ |
|
struct kvm_segment cs, ds, es, fs, gs, ss; |
|
struct kvm_segment tr, ldt; |
|
struct kvm_dtable gdt, idt; |
|
__u64 cr0, cr2, cr3, cr4, cr8; |
|
__u64 efer; |
|
__u64 apic_base; |
|
__u64 flags; |
|
__u64 pdptrs[4]; |
|
}; |
|
|
|
flags values for ``kvm_sregs2``: |
|
|
|
``KVM_SREGS2_FLAGS_PDPTRS_VALID`` |
|
|
|
Indicates thats the struct contain valid PDPTR values. |
|
|
|
|
|
4.132 KVM_SET_SREGS2 |
|
------------------ |
|
|
|
:Capability: KVM_CAP_SREGS2 |
|
:Architectures: x86 |
|
:Type: vcpu ioctl |
|
:Parameters: struct kvm_sregs2 (in) |
|
:Returns: 0 on success, -1 on error |
|
|
|
Writes special registers into the vcpu. |
|
See KVM_GET_SREGS2 for the data structures. |
|
This ioctl (when supported) replaces the KVM_SET_SREGS. |
|
|
|
4.133 KVM_GET_STATS_FD |
|
---------------------- |
|
|
|
:Capability: KVM_CAP_STATS_BINARY_FD |
|
:Architectures: all |
|
:Type: vm ioctl, vcpu ioctl |
|
:Parameters: none |
|
:Returns: statistics file descriptor on success, < 0 on error |
|
|
|
Errors: |
|
|
|
====== ====================================================== |
|
ENOMEM if the fd could not be created due to lack of memory |
|
EMFILE if the number of opened files exceeds the limit |
|
====== ====================================================== |
|
|
|
The returned file descriptor can be used to read VM/vCPU statistics data in |
|
binary format. The data in the file descriptor consists of four blocks |
|
organized as follows: |
|
|
|
+-------------+ |
|
| Header | |
|
+-------------+ |
|
| id string | |
|
+-------------+ |
|
| Descriptors | |
|
+-------------+ |
|
| Stats Data | |
|
+-------------+ |
|
|
|
Apart from the header starting at offset 0, please be aware that it is |
|
not guaranteed that the four blocks are adjacent or in the above order; |
|
the offsets of the id, descriptors and data blocks are found in the |
|
header. However, all four blocks are aligned to 64 bit offsets in the |
|
file and they do not overlap. |
|
|
|
All blocks except the data block are immutable. Userspace can read them |
|
only one time after retrieving the file descriptor, and then use ``pread`` or |
|
``lseek`` to read the statistics repeatedly. |
|
|
|
All data is in system endianness. |
|
|
|
The format of the header is as follows:: |
|
|
|
struct kvm_stats_header { |
|
__u32 flags; |
|
__u32 name_size; |
|
__u32 num_desc; |
|
__u32 id_offset; |
|
__u32 desc_offset; |
|
__u32 data_offset; |
|
}; |
|
|
|
The ``flags`` field is not used at the moment. It is always read as 0. |
|
|
|
The ``name_size`` field is the size (in byte) of the statistics name string |
|
(including trailing '\0') which is contained in the "id string" block and |
|
appended at the end of every descriptor. |
|
|
|
The ``num_desc`` field is the number of descriptors that are included in the |
|
descriptor block. (The actual number of values in the data block may be |
|
larger, since each descriptor may comprise more than one value). |
|
|
|
The ``id_offset`` field is the offset of the id string from the start of the |
|
file indicated by the file descriptor. It is a multiple of 8. |
|
|
|
The ``desc_offset`` field is the offset of the Descriptors block from the start |
|
of the file indicated by the file descriptor. It is a multiple of 8. |
|
|
|
The ``data_offset`` field is the offset of the Stats Data block from the start |
|
of the file indicated by the file descriptor. It is a multiple of 8. |
|
|
|
The id string block contains a string which identifies the file descriptor on |
|
which KVM_GET_STATS_FD was invoked. The size of the block, including the |
|
trailing ``'\0'``, is indicated by the ``name_size`` field in the header. |
|
|
|
The descriptors block is only needed to be read once for the lifetime of the |
|
file descriptor contains a sequence of ``struct kvm_stats_desc``, each followed |
|
by a string of size ``name_size``. |
|
|
|
#define KVM_STATS_TYPE_SHIFT 0 |
|
#define KVM_STATS_TYPE_MASK (0xF << KVM_STATS_TYPE_SHIFT) |
|
#define KVM_STATS_TYPE_CUMULATIVE (0x0 << KVM_STATS_TYPE_SHIFT) |
|
#define KVM_STATS_TYPE_INSTANT (0x1 << KVM_STATS_TYPE_SHIFT) |
|
#define KVM_STATS_TYPE_PEAK (0x2 << KVM_STATS_TYPE_SHIFT) |
|
|
|
#define KVM_STATS_UNIT_SHIFT 4 |
|
#define KVM_STATS_UNIT_MASK (0xF << KVM_STATS_UNIT_SHIFT) |
|
#define KVM_STATS_UNIT_NONE (0x0 << KVM_STATS_UNIT_SHIFT) |
|
#define KVM_STATS_UNIT_BYTES (0x1 << KVM_STATS_UNIT_SHIFT) |
|
#define KVM_STATS_UNIT_SECONDS (0x2 << KVM_STATS_UNIT_SHIFT) |
|
#define KVM_STATS_UNIT_CYCLES (0x3 << KVM_STATS_UNIT_SHIFT) |
|
|
|
#define KVM_STATS_BASE_SHIFT 8 |
|
#define KVM_STATS_BASE_MASK (0xF << KVM_STATS_BASE_SHIFT) |
|
#define KVM_STATS_BASE_POW10 (0x0 << KVM_STATS_BASE_SHIFT) |
|
#define KVM_STATS_BASE_POW2 (0x1 << KVM_STATS_BASE_SHIFT) |
|
|
|
struct kvm_stats_desc { |
|
__u32 flags; |
|
__s16 exponent; |
|
__u16 size; |
|
__u32 offset; |
|
__u32 unused; |
|
char name[]; |
|
}; |
|
|
|
The ``flags`` field contains the type and unit of the statistics data described |
|
by this descriptor. Its endianness is CPU native. |
|
The following flags are supported: |
|
|
|
Bits 0-3 of ``flags`` encode the type: |
|
* ``KVM_STATS_TYPE_CUMULATIVE`` |
|
The statistics data is cumulative. The value of data can only be increased. |
|
Most of the counters used in KVM are of this type. |
|
The corresponding ``size`` field for this type is always 1. |
|
All cumulative statistics data are read/write. |
|
* ``KVM_STATS_TYPE_INSTANT`` |
|
The statistics data is instantaneous. Its value can be increased or |
|
decreased. This type is usually used as a measurement of some resources, |
|
like the number of dirty pages, the number of large pages, etc. |
|
All instant statistics are read only. |
|
The corresponding ``size`` field for this type is always 1. |
|
* ``KVM_STATS_TYPE_PEAK`` |
|
The statistics data is peak. The value of data can only be increased, and |
|
represents a peak value for a measurement, for example the maximum number |
|
of items in a hash table bucket, the longest time waited and so on. |
|
The corresponding ``size`` field for this type is always 1. |
|
|
|
Bits 4-7 of ``flags`` encode the unit: |
|
* ``KVM_STATS_UNIT_NONE`` |
|
There is no unit for the value of statistics data. This usually means that |
|
the value is a simple counter of an event. |
|
* ``KVM_STATS_UNIT_BYTES`` |
|
It indicates that the statistics data is used to measure memory size, in the |
|
unit of Byte, KiByte, MiByte, GiByte, etc. The unit of the data is |
|
determined by the ``exponent`` field in the descriptor. |
|
* ``KVM_STATS_UNIT_SECONDS`` |
|
It indicates that the statistics data is used to measure time or latency. |
|
* ``KVM_STATS_UNIT_CYCLES`` |
|
It indicates that the statistics data is used to measure CPU clock cycles. |
|
|
|
Bits 8-11 of ``flags``, together with ``exponent``, encode the scale of the |
|
unit: |
|
* ``KVM_STATS_BASE_POW10`` |
|
The scale is based on power of 10. It is used for measurement of time and |
|
CPU clock cycles. For example, an exponent of -9 can be used with |
|
``KVM_STATS_UNIT_SECONDS`` to express that the unit is nanoseconds. |
|
* ``KVM_STATS_BASE_POW2`` |
|
The scale is based on power of 2. It is used for measurement of memory size. |
|
For example, an exponent of 20 can be used with ``KVM_STATS_UNIT_BYTES`` to |
|
express that the unit is MiB. |
|
|
|
The ``size`` field is the number of values of this statistics data. Its |
|
value is usually 1 for most of simple statistics. 1 means it contains an |
|
unsigned 64bit data. |
|
|
|
The ``offset`` field is the offset from the start of Data Block to the start of |
|
the corresponding statistics data. |
|
|
|
The ``unused`` field is reserved for future support for other types of |
|
statistics data, like log/linear histogram. Its value is always 0 for the types |
|
defined above. |
|
|
|
The ``name`` field is the name string of the statistics data. The name string |
|
starts at the end of ``struct kvm_stats_desc``. The maximum length including |
|
the trailing ``'\0'``, is indicated by ``name_size`` in the header. |
|
|
|
The Stats Data block contains an array of 64-bit values in the same order |
|
as the descriptors in Descriptors block. |
|
|
|
5. The kvm_run structure |
|
======================== |
|
|
|
Application code obtains a pointer to the kvm_run structure by |
|
mmap()ing a vcpu fd. From that point, application code can control |
|
execution by changing fields in kvm_run prior to calling the KVM_RUN |
|
ioctl, and obtain information about the reason KVM_RUN returned by |
|
looking up structure members. |
|
|
|
:: |
|
|
|
struct kvm_run { |
|
/* in */ |
|
__u8 request_interrupt_window; |
|
|
|
Request that KVM_RUN return when it becomes possible to inject external |
|
interrupts into the guest. Useful in conjunction with KVM_INTERRUPT. |
|
|
|
:: |
|
|
|
__u8 immediate_exit; |
|
|
|
This field is polled once when KVM_RUN starts; if non-zero, KVM_RUN |
|
exits immediately, returning -EINTR. In the common scenario where a |
|
signal is used to "kick" a VCPU out of KVM_RUN, this field can be used |
|
to avoid usage of KVM_SET_SIGNAL_MASK, which has worse scalability. |
|
Rather than blocking the signal outside KVM_RUN, userspace can set up |
|
a signal handler that sets run->immediate_exit to a non-zero value. |
|
|
|
This field is ignored if KVM_CAP_IMMEDIATE_EXIT is not available. |
|
|
|
:: |
|
|
|
__u8 padding1[6]; |
|
|
|
/* out */ |
|
__u32 exit_reason; |
|
|
|
When KVM_RUN has returned successfully (return value 0), this informs |
|
application code why KVM_RUN has returned. Allowable values for this |
|
field are detailed below. |
|
|
|
:: |
|
|
|
__u8 ready_for_interrupt_injection; |
|
|
|
If request_interrupt_window has been specified, this field indicates |
|
an interrupt can be injected now with KVM_INTERRUPT. |
|
|
|
:: |
|
|
|
__u8 if_flag; |
|
|
|
The value of the current interrupt flag. Only valid if in-kernel |
|
local APIC is not used. |
|
|
|
:: |
|
|
|
__u16 flags; |
|
|
|
More architecture-specific flags detailing state of the VCPU that may |
|
affect the device's behavior. Current defined flags:: |
|
|
|
/* x86, set if the VCPU is in system management mode */ |
|
#define KVM_RUN_X86_SMM (1 << 0) |
|
/* x86, set if bus lock detected in VM */ |
|
#define KVM_RUN_BUS_LOCK (1 << 1) |
|
|
|
:: |
|
|
|
/* in (pre_kvm_run), out (post_kvm_run) */ |
|
__u64 cr8; |
|
|
|
The value of the cr8 register. Only valid if in-kernel local APIC is |
|
not used. Both input and output. |
|
|
|
:: |
|
|
|
__u64 apic_base; |
|
|
|
The value of the APIC BASE msr. Only valid if in-kernel local |
|
APIC is not used. Both input and output. |
|
|
|
:: |
|
|
|
union { |
|
/* KVM_EXIT_UNKNOWN */ |
|
struct { |
|
__u64 hardware_exit_reason; |
|
} hw; |
|
|
|
If exit_reason is KVM_EXIT_UNKNOWN, the vcpu has exited due to unknown |
|
reasons. Further architecture-specific information is available in |
|
hardware_exit_reason. |
|
|
|
:: |
|
|
|
/* KVM_EXIT_FAIL_ENTRY */ |
|
struct { |
|
__u64 hardware_entry_failure_reason; |
|
__u32 cpu; /* if KVM_LAST_CPU */ |
|
} fail_entry; |
|
|
|
If exit_reason is KVM_EXIT_FAIL_ENTRY, the vcpu could not be run due |
|
to unknown reasons. Further architecture-specific information is |
|
available in hardware_entry_failure_reason. |
|
|
|
:: |
|
|
|
/* KVM_EXIT_EXCEPTION */ |
|
struct { |
|
__u32 exception; |
|
__u32 error_code; |
|
} ex; |
|
|
|
Unused. |
|
|
|
:: |
|
|
|
/* KVM_EXIT_IO */ |
|
struct { |
|
#define KVM_EXIT_IO_IN 0 |
|
#define KVM_EXIT_IO_OUT 1 |
|
__u8 direction; |
|
__u8 size; /* bytes */ |
|
__u16 port; |
|
__u32 count; |
|
__u64 data_offset; /* relative to kvm_run start */ |
|
} io; |
|
|
|
If exit_reason is KVM_EXIT_IO, then the vcpu has |
|
executed a port I/O instruction which could not be satisfied by kvm. |
|
data_offset describes where the data is located (KVM_EXIT_IO_OUT) or |
|
where kvm expects application code to place the data for the next |
|
KVM_RUN invocation (KVM_EXIT_IO_IN). Data format is a packed array. |
|
|
|
:: |
|
|
|
/* KVM_EXIT_DEBUG */ |
|
struct { |
|
struct kvm_debug_exit_arch arch; |
|
} debug; |
|
|
|
If the exit_reason is KVM_EXIT_DEBUG, then a vcpu is processing a debug event |
|
for which architecture specific information is returned. |
|
|
|
:: |
|
|
|
/* KVM_EXIT_MMIO */ |
|
struct { |
|
__u64 phys_addr; |
|
__u8 data[8]; |
|
__u32 len; |
|
__u8 is_write; |
|
} mmio; |
|
|
|
If exit_reason is KVM_EXIT_MMIO, then the vcpu has |
|
executed a memory-mapped I/O instruction which could not be satisfied |
|
by kvm. The 'data' member contains the written data if 'is_write' is |
|
true, and should be filled by application code otherwise. |
|
|
|
The 'data' member contains, in its first 'len' bytes, the value as it would |
|
appear if the VCPU performed a load or store of the appropriate width directly |
|
to the byte array. |
|
|
|
.. note:: |
|
|
|
For KVM_EXIT_IO, KVM_EXIT_MMIO, KVM_EXIT_OSI, KVM_EXIT_PAPR, KVM_EXIT_XEN, |
|
KVM_EXIT_EPR, KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR the corresponding |
|
operations are complete (and guest state is consistent) only after userspace |
|
has re-entered the kernel with KVM_RUN. The kernel side will first finish |
|
incomplete operations and then check for pending signals. |
|
|
|
The pending state of the operation is not preserved in state which is |
|
visible to userspace, thus userspace should ensure that the operation is |
|
completed before performing a live migration. Userspace can re-enter the |
|
guest with an unmasked signal pending or with the immediate_exit field set |
|
to complete pending operations without allowing any further instructions |
|
to be executed. |
|
|
|
:: |
|
|
|
/* KVM_EXIT_HYPERCALL */ |
|
struct { |
|
__u64 nr; |
|
__u64 args[6]; |
|
__u64 ret; |
|
__u32 longmode; |
|
__u32 pad; |
|
} hypercall; |
|
|
|
Unused. This was once used for 'hypercall to userspace'. To implement |
|
such functionality, use KVM_EXIT_IO (x86) or KVM_EXIT_MMIO (all except s390). |
|
|
|
.. note:: KVM_EXIT_IO is significantly faster than KVM_EXIT_MMIO. |
|
|
|
:: |
|
|
|
/* KVM_EXIT_TPR_ACCESS */ |
|
struct { |
|
__u64 rip; |
|
__u32 is_write; |
|
__u32 pad; |
|
} tpr_access; |
|
|
|
To be documented (KVM_TPR_ACCESS_REPORTING). |
|
|
|
:: |
|
|
|
/* KVM_EXIT_S390_SIEIC */ |
|
struct { |
|
__u8 icptcode; |
|
__u64 mask; /* psw upper half */ |
|
__u64 addr; /* psw lower half */ |
|
__u16 ipa; |
|
__u32 ipb; |
|
} s390_sieic; |
|
|
|
s390 specific. |
|
|
|
:: |
|
|
|
/* KVM_EXIT_S390_RESET */ |
|
#define KVM_S390_RESET_POR 1 |
|
#define KVM_S390_RESET_CLEAR 2 |
|
#define KVM_S390_RESET_SUBSYSTEM 4 |
|
#define KVM_S390_RESET_CPU_INIT 8 |
|
#define KVM_S390_RESET_IPL 16 |
|
__u64 s390_reset_flags; |
|
|
|
s390 specific. |
|
|
|
:: |
|
|
|
/* KVM_EXIT_S390_UCONTROL */ |
|
struct { |
|
__u64 trans_exc_code; |
|
__u32 pgm_code; |
|
} s390_ucontrol; |
|
|
|
s390 specific. A page fault has occurred for a user controlled virtual |
|
machine (KVM_VM_S390_UNCONTROL) on it's host page table that cannot be |
|
resolved by the kernel. |
|
The program code and the translation exception code that were placed |
|
in the cpu's lowcore are presented here as defined by the z Architecture |
|
Principles of Operation Book in the Chapter for Dynamic Address Translation |
|
(DAT) |
|
|
|
:: |
|
|
|
/* KVM_EXIT_DCR */ |
|
struct { |
|
__u32 dcrn; |
|
__u32 data; |
|
__u8 is_write; |
|
} dcr; |
|
|
|
Deprecated - was used for 440 KVM. |
|
|
|
:: |
|
|
|
/* KVM_EXIT_OSI */ |
|
struct { |
|
__u64 gprs[32]; |
|
} osi; |
|
|
|
MOL uses a special hypercall interface it calls 'OSI'. To enable it, we catch |
|
hypercalls and exit with this exit struct that contains all the guest gprs. |
|
|
|
If exit_reason is KVM_EXIT_OSI, then the vcpu has triggered such a hypercall. |
|
Userspace can now handle the hypercall and when it's done modify the gprs as |
|
necessary. Upon guest entry all guest GPRs will then be replaced by the values |
|
in this struct. |
|
|
|
:: |
|
|
|
/* KVM_EXIT_PAPR_HCALL */ |
|
struct { |
|
__u64 nr; |
|
__u64 ret; |
|
__u64 args[9]; |
|
} papr_hcall; |
|
|
|
This is used on 64-bit PowerPC when emulating a pSeries partition, |
|
e.g. with the 'pseries' machine type in qemu. It occurs when the |
|
guest does a hypercall using the 'sc 1' instruction. The 'nr' field |
|
contains the hypercall number (from the guest R3), and 'args' contains |
|
the arguments (from the guest R4 - R12). Userspace should put the |
|
return code in 'ret' and any extra returned values in args[]. |
|
The possible hypercalls are defined in the Power Architecture Platform |
|
Requirements (PAPR) document available from www.power.org (free |
|
developer registration required to access it). |
|
|
|
:: |
|
|
|
/* KVM_EXIT_S390_TSCH */ |
|
struct { |
|
__u16 subchannel_id; |
|
__u16 subchannel_nr; |
|
__u32 io_int_parm; |
|
__u32 io_int_word; |
|
__u32 ipb; |
|
__u8 dequeued; |
|
} s390_tsch; |
|
|
|
s390 specific. This exit occurs when KVM_CAP_S390_CSS_SUPPORT has been enabled |
|
and TEST SUBCHANNEL was intercepted. If dequeued is set, a pending I/O |
|
interrupt for the target subchannel has been dequeued and subchannel_id, |
|
subchannel_nr, io_int_parm and io_int_word contain the parameters for that |
|
interrupt. ipb is needed for instruction parameter decoding. |
|
|
|
:: |
|
|
|
/* KVM_EXIT_EPR */ |
|
struct { |
|
__u32 epr; |
|
} epr; |
|
|
|
On FSL BookE PowerPC chips, the interrupt controller has a fast patch |
|
interrupt acknowledge path to the core. When the core successfully |
|
delivers an interrupt, it automatically populates the EPR register with |
|
the interrupt vector number and acknowledges the interrupt inside |
|
the interrupt controller. |
|
|
|
In case the interrupt controller lives in user space, we need to do |
|
the interrupt acknowledge cycle through it to fetch the next to be |
|
delivered interrupt vector using this exit. |
|
|
|
It gets triggered whenever both KVM_CAP_PPC_EPR are enabled and an |
|
external interrupt has just been delivered into the guest. User space |
|
should put the acknowledged interrupt vector into the 'epr' field. |
|
|
|
:: |
|
|
|
/* KVM_EXIT_SYSTEM_EVENT */ |
|
struct { |
|
#define KVM_SYSTEM_EVENT_SHUTDOWN 1 |
|
#define KVM_SYSTEM_EVENT_RESET 2 |
|
#define KVM_SYSTEM_EVENT_CRASH 3 |
|
__u32 type; |
|
__u64 flags; |
|
} system_event; |
|
|
|
If exit_reason is KVM_EXIT_SYSTEM_EVENT then the vcpu has triggered |
|
a system-level event using some architecture specific mechanism (hypercall |
|
or some special instruction). In case of ARM/ARM64, this is triggered using |
|
HVC instruction based PSCI call from the vcpu. The 'type' field describes |
|
the system-level event type. The 'flags' field describes architecture |
|
specific flags for the system-level event. |
|
|
|
Valid values for 'type' are: |
|
|
|
- KVM_SYSTEM_EVENT_SHUTDOWN -- the guest has requested a shutdown of the |
|
VM. Userspace is not obliged to honour this, and if it does honour |
|
this does not need to destroy the VM synchronously (ie it may call |
|
KVM_RUN again before shutdown finally occurs). |
|
- KVM_SYSTEM_EVENT_RESET -- the guest has requested a reset of the VM. |
|
As with SHUTDOWN, userspace can choose to ignore the request, or |
|
to schedule the reset to occur in the future and may call KVM_RUN again. |
|
- KVM_SYSTEM_EVENT_CRASH -- the guest crash occurred and the guest |
|
has requested a crash condition maintenance. Userspace can choose |
|
to ignore the request, or to gather VM memory core dump and/or |
|
reset/shutdown of the VM. |
|
|
|
:: |
|
|
|
/* KVM_EXIT_IOAPIC_EOI */ |
|
struct { |
|
__u8 vector; |
|
} eoi; |
|
|
|
Indicates that the VCPU's in-kernel local APIC received an EOI for a |
|
level-triggered IOAPIC interrupt. This exit only triggers when the |
|
IOAPIC is implemented in userspace (i.e. KVM_CAP_SPLIT_IRQCHIP is enabled); |
|
the userspace IOAPIC should process the EOI and retrigger the interrupt if |
|
it is still asserted. Vector is the LAPIC interrupt vector for which the |
|
EOI was received. |
|
|
|
:: |
|
|
|
struct kvm_hyperv_exit { |
|
#define KVM_EXIT_HYPERV_SYNIC 1 |
|
#define KVM_EXIT_HYPERV_HCALL 2 |
|
#define KVM_EXIT_HYPERV_SYNDBG 3 |
|
__u32 type; |
|
__u32 pad1; |
|
union { |
|
struct { |
|
__u32 msr; |
|
__u32 pad2; |
|
__u64 control; |
|
__u64 evt_page; |
|
__u64 msg_page; |
|
} synic; |
|
struct { |
|
__u64 input; |
|
__u64 result; |
|
__u64 params[2]; |
|
} hcall; |
|
struct { |
|
__u32 msr; |
|
__u32 pad2; |
|
__u64 control; |
|
__u64 status; |
|
__u64 send_page; |
|
__u64 recv_page; |
|
__u64 pending_page; |
|
} syndbg; |
|
} u; |
|
}; |
|
/* KVM_EXIT_HYPERV */ |
|
struct kvm_hyperv_exit hyperv; |
|
|
|
Indicates that the VCPU exits into userspace to process some tasks |
|
related to Hyper-V emulation. |
|
|
|
Valid values for 'type' are: |
|
|
|
- KVM_EXIT_HYPERV_SYNIC -- synchronously notify user-space about |
|
|
|
Hyper-V SynIC state change. Notification is used to remap SynIC |
|
event/message pages and to enable/disable SynIC messages/events processing |
|
in userspace. |
|
|
|
- KVM_EXIT_HYPERV_SYNDBG -- synchronously notify user-space about |
|
|
|
Hyper-V Synthetic debugger state change. Notification is used to either update |
|
the pending_page location or to send a control command (send the buffer located |
|
in send_page or recv a buffer to recv_page). |
|
|
|
:: |
|
|
|
/* KVM_EXIT_ARM_NISV */ |
|
struct { |
|
__u64 esr_iss; |
|
__u64 fault_ipa; |
|
} arm_nisv; |
|
|
|
Used on arm and arm64 systems. If a guest accesses memory not in a memslot, |
|
KVM will typically return to userspace and ask it to do MMIO emulation on its |
|
behalf. However, for certain classes of instructions, no instruction decode |
|
(direction, length of memory access) is provided, and fetching and decoding |
|
the instruction from the VM is overly complicated to live in the kernel. |
|
|
|
Historically, when this situation occurred, KVM would print a warning and kill |
|
the VM. KVM assumed that if the guest accessed non-memslot memory, it was |
|
trying to do I/O, which just couldn't be emulated, and the warning message was |
|
phrased accordingly. However, what happened more often was that a guest bug |
|
caused access outside the guest memory areas which should lead to a more |
|
meaningful warning message and an external abort in the guest, if the access |
|
did not fall within an I/O window. |
|
|
|
Userspace implementations can query for KVM_CAP_ARM_NISV_TO_USER, and enable |
|
this capability at VM creation. Once this is done, these types of errors will |
|
instead return to userspace with KVM_EXIT_ARM_NISV, with the valid bits from |
|
the HSR (arm) and ESR_EL2 (arm64) in the esr_iss field, and the faulting IPA |
|
in the fault_ipa field. Userspace can either fix up the access if it's |
|
actually an I/O access by decoding the instruction from guest memory (if it's |
|
very brave) and continue executing the guest, or it can decide to suspend, |
|
dump, or restart the guest. |
|
|
|
Note that KVM does not skip the faulting instruction as it does for |
|
KVM_EXIT_MMIO, but userspace has to emulate any change to the processing state |
|
if it decides to decode and emulate the instruction. |
|
|
|
:: |
|
|
|
/* KVM_EXIT_X86_RDMSR / KVM_EXIT_X86_WRMSR */ |
|
struct { |
|
__u8 error; /* user -> kernel */ |
|
__u8 pad[7]; |
|
__u32 reason; /* kernel -> user */ |
|
__u32 index; /* kernel -> user */ |
|
__u64 data; /* kernel <-> user */ |
|
} msr; |
|
|
|
Used on x86 systems. When the VM capability KVM_CAP_X86_USER_SPACE_MSR is |
|
enabled, MSR accesses to registers that would invoke a #GP by KVM kernel code |
|
will instead trigger a KVM_EXIT_X86_RDMSR exit for reads and KVM_EXIT_X86_WRMSR |
|
exit for writes. |
|
|
|
The "reason" field specifies why the MSR trap occurred. User space will only |
|
receive MSR exit traps when a particular reason was requested during through |
|
ENABLE_CAP. Currently valid exit reasons are: |
|
|
|
KVM_MSR_EXIT_REASON_UNKNOWN - access to MSR that is unknown to KVM |
|
KVM_MSR_EXIT_REASON_INVAL - access to invalid MSRs or reserved bits |
|
KVM_MSR_EXIT_REASON_FILTER - access blocked by KVM_X86_SET_MSR_FILTER |
|
|
|
For KVM_EXIT_X86_RDMSR, the "index" field tells user space which MSR the guest |
|
wants to read. To respond to this request with a successful read, user space |
|
writes the respective data into the "data" field and must continue guest |
|
execution to ensure the read data is transferred into guest register state. |
|
|
|
If the RDMSR request was unsuccessful, user space indicates that with a "1" in |
|
the "error" field. This will inject a #GP into the guest when the VCPU is |
|
executed again. |
|
|
|
For KVM_EXIT_X86_WRMSR, the "index" field tells user space which MSR the guest |
|
wants to write. Once finished processing the event, user space must continue |
|
vCPU execution. If the MSR write was unsuccessful, user space also sets the |
|
"error" field to "1". |
|
|
|
:: |
|
|
|
|
|
struct kvm_xen_exit { |
|
#define KVM_EXIT_XEN_HCALL 1 |
|
__u32 type; |
|
union { |
|
struct { |
|
__u32 longmode; |
|
__u32 cpl; |
|
__u64 input; |
|
__u64 result; |
|
__u64 params[6]; |
|
} hcall; |
|
} u; |
|
}; |
|
/* KVM_EXIT_XEN */ |
|
struct kvm_hyperv_exit xen; |
|
|
|
Indicates that the VCPU exits into userspace to process some tasks |
|
related to Xen emulation. |
|
|
|
Valid values for 'type' are: |
|
|
|
- KVM_EXIT_XEN_HCALL -- synchronously notify user-space about Xen hypercall. |
|
Userspace is expected to place the hypercall result into the appropriate |
|
field before invoking KVM_RUN again. |
|
|
|
:: |
|
|
|
/* Fix the size of the union. */ |
|
char padding[256]; |
|
}; |
|
|
|
/* |
|
* shared registers between kvm and userspace. |
|
* kvm_valid_regs specifies the register classes set by the host |
|
* kvm_dirty_regs specified the register classes dirtied by userspace |
|
* struct kvm_sync_regs is architecture specific, as well as the |
|
* bits for kvm_valid_regs and kvm_dirty_regs |
|
*/ |
|
__u64 kvm_valid_regs; |
|
__u64 kvm_dirty_regs; |
|
union { |
|
struct kvm_sync_regs regs; |
|
char padding[SYNC_REGS_SIZE_BYTES]; |
|
} s; |
|
|
|
If KVM_CAP_SYNC_REGS is defined, these fields allow userspace to access |
|
certain guest registers without having to call SET/GET_*REGS. Thus we can |
|
avoid some system call overhead if userspace has to handle the exit. |
|
Userspace can query the validity of the structure by checking |
|
kvm_valid_regs for specific bits. These bits are architecture specific |
|
and usually define the validity of a groups of registers. (e.g. one bit |
|
for general purpose registers) |
|
|
|
Please note that the kernel is allowed to use the kvm_run structure as the |
|
primary storage for certain register types. Therefore, the kernel may use the |
|
values in kvm_run even if the corresponding bit in kvm_dirty_regs is not set. |
|
|
|
:: |
|
|
|
}; |
|
|
|
|
|
|
|
6. Capabilities that can be enabled on vCPUs |
|
============================================ |
|
|
|
There are certain capabilities that change the behavior of the virtual CPU or |
|
the virtual machine when enabled. To enable them, please see section 4.37. |
|
Below you can find a list of capabilities and what their effect on the vCPU or |
|
the virtual machine is when enabling them. |
|
|
|
The following information is provided along with the description: |
|
|
|
Architectures: |
|
which instruction set architectures provide this ioctl. |
|
x86 includes both i386 and x86_64. |
|
|
|
Target: |
|
whether this is a per-vcpu or per-vm capability. |
|
|
|
Parameters: |
|
what parameters are accepted by the capability. |
|
|
|
Returns: |
|
the return value. General error numbers (EBADF, ENOMEM, EINVAL) |
|
are not detailed, but errors with specific meanings are. |
|
|
|
|
|
6.1 KVM_CAP_PPC_OSI |
|
------------------- |
|
|
|
:Architectures: ppc |
|
:Target: vcpu |
|
:Parameters: none |
|
:Returns: 0 on success; -1 on error |
|
|
|
This capability enables interception of OSI hypercalls that otherwise would |
|
be treated as normal system calls to be injected into the guest. OSI hypercalls |
|
were invented by Mac-on-Linux to have a standardized communication mechanism |
|
between the guest and the host. |
|
|
|
When this capability is enabled, KVM_EXIT_OSI can occur. |
|
|
|
|
|
6.2 KVM_CAP_PPC_PAPR |
|
-------------------- |
|
|
|
:Architectures: ppc |
|
:Target: vcpu |
|
:Parameters: none |
|
:Returns: 0 on success; -1 on error |
|
|
|
This capability enables interception of PAPR hypercalls. PAPR hypercalls are |
|
done using the hypercall instruction "sc 1". |
|
|
|
It also sets the guest privilege level to "supervisor" mode. Usually the guest |
|
runs in "hypervisor" privilege mode with a few missing features. |
|
|
|
In addition to the above, it changes the semantics of SDR1. In this mode, the |
|
HTAB address part of SDR1 contains an HVA instead of a GPA, as PAPR keeps the |
|
HTAB invisible to the guest. |
|
|
|
When this capability is enabled, KVM_EXIT_PAPR_HCALL can occur. |
|
|
|
|
|
6.3 KVM_CAP_SW_TLB |
|
------------------ |
|
|
|
:Architectures: ppc |
|
:Target: vcpu |
|
:Parameters: args[0] is the address of a struct kvm_config_tlb |
|
:Returns: 0 on success; -1 on error |
|
|
|
:: |
|
|
|
struct kvm_config_tlb { |
|
__u64 params; |
|
__u64 array; |
|
__u32 mmu_type; |
|
__u32 array_len; |
|
}; |
|
|
|
Configures the virtual CPU's TLB array, establishing a shared memory area |
|
between userspace and KVM. The "params" and "array" fields are userspace |
|
addresses of mmu-type-specific data structures. The "array_len" field is an |
|
safety mechanism, and should be set to the size in bytes of the memory that |
|
userspace has reserved for the array. It must be at least the size dictated |
|
by "mmu_type" and "params". |
|
|
|
While KVM_RUN is active, the shared region is under control of KVM. Its |
|
contents are undefined, and any modification by userspace results in |
|
boundedly undefined behavior. |
|
|
|
On return from KVM_RUN, the shared region will reflect the current state of |
|
the guest's TLB. If userspace makes any changes, it must call KVM_DIRTY_TLB |
|
to tell KVM which entries have been changed, prior to calling KVM_RUN again |
|
on this vcpu. |
|
|
|
For mmu types KVM_MMU_FSL_BOOKE_NOHV and KVM_MMU_FSL_BOOKE_HV: |
|
|
|
- The "params" field is of type "struct kvm_book3e_206_tlb_params". |
|
- The "array" field points to an array of type "struct |
|
kvm_book3e_206_tlb_entry". |
|
- The array consists of all entries in the first TLB, followed by all |
|
entries in the second TLB. |
|
- Within a TLB, entries are ordered first by increasing set number. Within a |
|
set, entries are ordered by way (increasing ESEL). |
|
- The hash for determining set number in TLB0 is: (MAS2 >> 12) & (num_sets - 1) |
|
where "num_sets" is the tlb_sizes[] value divided by the tlb_ways[] value. |
|
- The tsize field of mas1 shall be set to 4K on TLB0, even though the |
|
hardware ignores this value for TLB0. |
|
|
|
6.4 KVM_CAP_S390_CSS_SUPPORT |
|
---------------------------- |
|
|
|
:Architectures: s390 |
|
:Target: vcpu |
|
:Parameters: none |
|
:Returns: 0 on success; -1 on error |
|
|
|
This capability enables support for handling of channel I/O instructions. |
|
|
|
TEST PENDING INTERRUPTION and the interrupt portion of TEST SUBCHANNEL are |
|
handled in-kernel, while the other I/O instructions are passed to userspace. |
|
|
|
When this capability is enabled, KVM_EXIT_S390_TSCH will occur on TEST |
|
SUBCHANNEL intercepts. |
|
|
|
Note that even though this capability is enabled per-vcpu, the complete |
|
virtual machine is affected. |
|
|
|
6.5 KVM_CAP_PPC_EPR |
|
------------------- |
|
|
|
:Architectures: ppc |
|
:Target: vcpu |
|
:Parameters: args[0] defines whether the proxy facility is active |
|
:Returns: 0 on success; -1 on error |
|
|
|
This capability enables or disables the delivery of interrupts through the |
|
external proxy facility. |
|
|
|
When enabled (args[0] != 0), every time the guest gets an external interrupt |
|
delivered, it automatically exits into user space with a KVM_EXIT_EPR exit |
|
to receive the topmost interrupt vector. |
|
|
|
When disabled (args[0] == 0), behavior is as if this facility is unsupported. |
|
|
|
When this capability is enabled, KVM_EXIT_EPR can occur. |
|
|
|
6.6 KVM_CAP_IRQ_MPIC |
|
-------------------- |
|
|
|
:Architectures: ppc |
|
:Parameters: args[0] is the MPIC device fd; |
|
args[1] is the MPIC CPU number for this vcpu |
|
|
|
This capability connects the vcpu to an in-kernel MPIC device. |
|
|
|
6.7 KVM_CAP_IRQ_XICS |
|
-------------------- |
|
|
|
:Architectures: ppc |
|
:Target: vcpu |
|
:Parameters: args[0] is the XICS device fd; |
|
args[1] is the XICS CPU number (server ID) for this vcpu |
|
|
|
This capability connects the vcpu to an in-kernel XICS device. |
|
|
|
6.8 KVM_CAP_S390_IRQCHIP |
|
------------------------ |
|
|
|
:Architectures: s390 |
|
:Target: vm |
|
:Parameters: none |
|
|
|
This capability enables the in-kernel irqchip for s390. Please refer to |
|
"4.24 KVM_CREATE_IRQCHIP" for details. |
|
|
|
6.9 KVM_CAP_MIPS_FPU |
|
-------------------- |
|
|
|
:Architectures: mips |
|
:Target: vcpu |
|
:Parameters: args[0] is reserved for future use (should be 0). |
|
|
|
This capability allows the use of the host Floating Point Unit by the guest. It |
|
allows the Config1.FP bit to be set to enable the FPU in the guest. Once this is |
|
done the ``KVM_REG_MIPS_FPR_*`` and ``KVM_REG_MIPS_FCR_*`` registers can be |
|
accessed (depending on the current guest FPU register mode), and the Status.FR, |
|
Config5.FRE bits are accessible via the KVM API and also from the guest, |
|
depending on them being supported by the FPU. |
|
|
|
6.10 KVM_CAP_MIPS_MSA |
|
--------------------- |
|
|
|
:Architectures: mips |
|
:Target: vcpu |
|
:Parameters: args[0] is reserved for future use (should be 0). |
|
|
|
This capability allows the use of the MIPS SIMD Architecture (MSA) by the guest. |
|
It allows the Config3.MSAP bit to be set to enable the use of MSA by the guest. |
|
Once this is done the ``KVM_REG_MIPS_VEC_*`` and ``KVM_REG_MIPS_MSA_*`` |
|
registers can be accessed, and the Config5.MSAEn bit is accessible via the |
|
KVM API and also from the guest. |
|
|
|
6.74 KVM_CAP_SYNC_REGS |
|
---------------------- |
|
|
|
:Architectures: s390, x86 |
|
:Target: s390: always enabled, x86: vcpu |
|
:Parameters: none |
|
:Returns: x86: KVM_CHECK_EXTENSION returns a bit-array indicating which register |
|
sets are supported |
|
(bitfields defined in arch/x86/include/uapi/asm/kvm.h). |
|
|
|
As described above in the kvm_sync_regs struct info in section 5 (kvm_run): |
|
KVM_CAP_SYNC_REGS "allow[s] userspace to access certain guest registers |
|
without having to call SET/GET_*REGS". This reduces overhead by eliminating |
|
repeated ioctl calls for setting and/or getting register values. This is |
|
particularly important when userspace is making synchronous guest state |
|
modifications, e.g. when emulating and/or intercepting instructions in |
|
userspace. |
|
|
|
For s390 specifics, please refer to the source code. |
|
|
|
For x86: |
|
|
|
- the register sets to be copied out to kvm_run are selectable |
|
by userspace (rather that all sets being copied out for every exit). |
|
- vcpu_events are available in addition to regs and sregs. |
|
|
|
For x86, the 'kvm_valid_regs' field of struct kvm_run is overloaded to |
|
function as an input bit-array field set by userspace to indicate the |
|
specific register sets to be copied out on the next exit. |
|
|
|
To indicate when userspace has modified values that should be copied into |
|
the vCPU, the all architecture bitarray field, 'kvm_dirty_regs' must be set. |
|
This is done using the same bitflags as for the 'kvm_valid_regs' field. |
|
If the dirty bit is not set, then the register set values will not be copied |
|
into the vCPU even if they've been modified. |
|
|
|
Unused bitfields in the bitarrays must be set to zero. |
|
|
|
:: |
|
|
|
struct kvm_sync_regs { |
|
struct kvm_regs regs; |
|
struct kvm_sregs sregs; |
|
struct kvm_vcpu_events events; |
|
}; |
|
|
|
6.75 KVM_CAP_PPC_IRQ_XIVE |
|
------------------------- |
|
|
|
:Architectures: ppc |
|
:Target: vcpu |
|
:Parameters: args[0] is the XIVE device fd; |
|
args[1] is the XIVE CPU number (server ID) for this vcpu |
|
|
|
This capability connects the vcpu to an in-kernel XIVE device. |
|
|
|
7. Capabilities that can be enabled on VMs |
|
========================================== |
|
|
|
There are certain capabilities that change the behavior of the virtual |
|
machine when enabled. To enable them, please see section 4.37. Below |
|
you can find a list of capabilities and what their effect on the VM |
|
is when enabling them. |
|
|
|
The following information is provided along with the description: |
|
|
|
Architectures: |
|
which instruction set architectures provide this ioctl. |
|
x86 includes both i386 and x86_64. |
|
|
|
Parameters: |
|
what parameters are accepted by the capability. |
|
|
|
Returns: |
|
the return value. General error numbers (EBADF, ENOMEM, EINVAL) |
|
are not detailed, but errors with specific meanings are. |
|
|
|
|
|
7.1 KVM_CAP_PPC_ENABLE_HCALL |
|
---------------------------- |
|
|
|
:Architectures: ppc |
|
:Parameters: args[0] is the sPAPR hcall number; |
|
args[1] is 0 to disable, 1 to enable in-kernel handling |
|
|
|
This capability controls whether individual sPAPR hypercalls (hcalls) |
|
get handled by the kernel or not. Enabling or disabling in-kernel |
|
handling of an hcall is effective across the VM. On creation, an |
|
initial set of hcalls are enabled for in-kernel handling, which |
|
consists of those hcalls for which in-kernel handlers were implemented |
|
before this capability was implemented. If disabled, the kernel will |
|
not to attempt to handle the hcall, but will always exit to userspace |
|
to handle it. Note that it may not make sense to enable some and |
|
disable others of a group of related hcalls, but KVM does not prevent |
|
userspace from doing that. |
|
|
|
If the hcall number specified is not one that has an in-kernel |
|
implementation, the KVM_ENABLE_CAP ioctl will fail with an EINVAL |
|
error. |
|
|
|
7.2 KVM_CAP_S390_USER_SIGP |
|
-------------------------- |
|
|
|
:Architectures: s390 |
|
:Parameters: none |
|
|
|
This capability controls which SIGP orders will be handled completely in user |
|
space. With this capability enabled, all fast orders will be handled completely |
|
in the kernel: |
|
|
|
- SENSE |
|
- SENSE RUNNING |
|
- EXTERNAL CALL |
|
- EMERGENCY SIGNAL |
|
- CONDITIONAL EMERGENCY SIGNAL |
|
|
|
All other orders will be handled completely in user space. |
|
|
|
Only privileged operation exceptions will be checked for in the kernel (or even |
|
in the hardware prior to interception). If this capability is not enabled, the |
|
old way of handling SIGP orders is used (partially in kernel and user space). |
|
|
|
7.3 KVM_CAP_S390_VECTOR_REGISTERS |
|
--------------------------------- |
|
|
|
:Architectures: s390 |
|
:Parameters: none |
|
:Returns: 0 on success, negative value on error |
|
|
|
Allows use of the vector registers introduced with z13 processor, and |
|
provides for the synchronization between host and user space. Will |
|
return -EINVAL if the machine does not support vectors. |
|
|
|
7.4 KVM_CAP_S390_USER_STSI |
|
-------------------------- |
|
|
|
:Architectures: s390 |
|
:Parameters: none |
|
|
|
This capability allows post-handlers for the STSI instruction. After |
|
initial handling in the kernel, KVM exits to user space with |
|
KVM_EXIT_S390_STSI to allow user space to insert further data. |
|
|
|
Before exiting to userspace, kvm handlers should fill in s390_stsi field of |
|
vcpu->run:: |
|
|
|
struct { |
|
__u64 addr; |
|
__u8 ar; |
|
__u8 reserved; |
|
__u8 fc; |
|
__u8 sel1; |
|
__u16 sel2; |
|
} s390_stsi; |
|
|
|
@addr - guest address of STSI SYSIB |
|
@fc - function code |
|
@sel1 - selector 1 |
|
@sel2 - selector 2 |
|
@ar - access register number |
|
|
|
KVM handlers should exit to userspace with rc = -EREMOTE. |
|
|
|
7.5 KVM_CAP_SPLIT_IRQCHIP |
|
------------------------- |
|
|
|
:Architectures: x86 |
|
:Parameters: args[0] - number of routes reserved for userspace IOAPICs |
|
:Returns: 0 on success, -1 on error |
|
|
|
Create a local apic for each processor in the kernel. This can be used |
|
instead of KVM_CREATE_IRQCHIP if the userspace VMM wishes to emulate the |
|
IOAPIC and PIC (and also the PIT, even though this has to be enabled |
|
separately). |
|
|
|
This capability also enables in kernel routing of interrupt requests; |
|
when KVM_CAP_SPLIT_IRQCHIP only routes of KVM_IRQ_ROUTING_MSI type are |
|
used in the IRQ routing table. The first args[0] MSI routes are reserved |
|
for the IOAPIC pins. Whenever the LAPIC receives an EOI for these routes, |
|
a KVM_EXIT_IOAPIC_EOI vmexit will be reported to userspace. |
|
|
|
Fails if VCPU has already been created, or if the irqchip is already in the |
|
kernel (i.e. KVM_CREATE_IRQCHIP has already been called). |
|
|
|
7.6 KVM_CAP_S390_RI |
|
------------------- |
|
|
|
:Architectures: s390 |
|
:Parameters: none |
|
|
|
Allows use of runtime-instrumentation introduced with zEC12 processor. |
|
Will return -EINVAL if the machine does not support runtime-instrumentation. |
|
Will return -EBUSY if a VCPU has already been created. |
|
|
|
7.7 KVM_CAP_X2APIC_API |
|
---------------------- |
|
|
|
:Architectures: x86 |
|
:Parameters: args[0] - features that should be enabled |
|
:Returns: 0 on success, -EINVAL when args[0] contains invalid features |
|
|
|
Valid feature flags in args[0] are:: |
|
|
|
#define KVM_X2APIC_API_USE_32BIT_IDS (1ULL << 0) |
|
#define KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK (1ULL << 1) |
|
|
|
Enabling KVM_X2APIC_API_USE_32BIT_IDS changes the behavior of |
|
KVM_SET_GSI_ROUTING, KVM_SIGNAL_MSI, KVM_SET_LAPIC, and KVM_GET_LAPIC, |
|
allowing the use of 32-bit APIC IDs. See KVM_CAP_X2APIC_API in their |
|
respective sections. |
|
|
|
KVM_X2APIC_API_DISABLE_BROADCAST_QUIRK must be enabled for x2APIC to work |
|
in logical mode or with more than 255 VCPUs. Otherwise, KVM treats 0xff |
|
as a broadcast even in x2APIC mode in order to support physical x2APIC |
|
without interrupt remapping. This is undesirable in logical mode, |
|
where 0xff represents CPUs 0-7 in cluster 0. |
|
|
|
7.8 KVM_CAP_S390_USER_INSTR0 |
|
---------------------------- |
|
|
|
:Architectures: s390 |
|
:Parameters: none |
|
|
|
With this capability enabled, all illegal instructions 0x0000 (2 bytes) will |
|
be intercepted and forwarded to user space. User space can use this |
|
mechanism e.g. to realize 2-byte software breakpoints. The kernel will |
|
not inject an operating exception for these instructions, user space has |
|
to take care of that. |
|
|
|
This capability can be enabled dynamically even if VCPUs were already |
|
created and are running. |
|
|
|
7.9 KVM_CAP_S390_GS |
|
------------------- |
|
|
|
:Architectures: s390 |
|
:Parameters: none |
|
:Returns: 0 on success; -EINVAL if the machine does not support |
|
guarded storage; -EBUSY if a VCPU has already been created. |
|
|
|
Allows use of guarded storage for the KVM guest. |
|
|
|
7.10 KVM_CAP_S390_AIS |
|
--------------------- |
|
|
|
:Architectures: s390 |
|
:Parameters: none |
|
|
|
Allow use of adapter-interruption suppression. |
|
:Returns: 0 on success; -EBUSY if a VCPU has already been created. |
|
|
|
7.11 KVM_CAP_PPC_SMT |
|
-------------------- |
|
|
|
:Architectures: ppc |
|
:Parameters: vsmt_mode, flags |
|
|
|
Enabling this capability on a VM provides userspace with a way to set |
|
the desired virtual SMT mode (i.e. the number of virtual CPUs per |
|
virtual core). The virtual SMT mode, vsmt_mode, must be a power of 2 |
|
between 1 and 8. On POWER8, vsmt_mode must also be no greater than |
|
the number of threads per subcore for the host. Currently flags must |
|
be 0. A successful call to enable this capability will result in |
|
vsmt_mode being returned when the KVM_CAP_PPC_SMT capability is |
|
subsequently queried for the VM. This capability is only supported by |
|
HV KVM, and can only be set before any VCPUs have been created. |
|
The KVM_CAP_PPC_SMT_POSSIBLE capability indicates which virtual SMT |
|
modes are available. |
|
|
|
7.12 KVM_CAP_PPC_FWNMI |
|
---------------------- |
|
|
|
:Architectures: ppc |
|
:Parameters: none |
|
|
|
With this capability a machine check exception in the guest address |
|
space will cause KVM to exit the guest with NMI exit reason. This |
|
enables QEMU to build error log and branch to guest kernel registered |
|
machine check handling routine. Without this capability KVM will |
|
branch to guests' 0x200 interrupt vector. |
|
|
|
7.13 KVM_CAP_X86_DISABLE_EXITS |
|
------------------------------ |
|
|
|
:Architectures: x86 |
|
:Parameters: args[0] defines which exits are disabled |
|
:Returns: 0 on success, -EINVAL when args[0] contains invalid exits |
|
|
|
Valid bits in args[0] are:: |
|
|
|
#define KVM_X86_DISABLE_EXITS_MWAIT (1 << 0) |
|
#define KVM_X86_DISABLE_EXITS_HLT (1 << 1) |
|
#define KVM_X86_DISABLE_EXITS_PAUSE (1 << 2) |
|
#define KVM_X86_DISABLE_EXITS_CSTATE (1 << 3) |
|
|
|
Enabling this capability on a VM provides userspace with a way to no |
|
longer intercept some instructions for improved latency in some |
|
workloads, and is suggested when vCPUs are associated to dedicated |
|
physical CPUs. More bits can be added in the future; userspace can |
|
just pass the KVM_CHECK_EXTENSION result to KVM_ENABLE_CAP to disable |
|
all such vmexits. |
|
|
|
Do not enable KVM_FEATURE_PV_UNHALT if you disable HLT exits. |
|
|
|
7.14 KVM_CAP_S390_HPAGE_1M |
|
-------------------------- |
|
|
|
:Architectures: s390 |
|
:Parameters: none |
|
:Returns: 0 on success, -EINVAL if hpage module parameter was not set |
|
or cmma is enabled, or the VM has the KVM_VM_S390_UCONTROL |
|
flag set |
|
|
|
With this capability the KVM support for memory backing with 1m pages |
|
through hugetlbfs can be enabled for a VM. After the capability is |
|
enabled, cmma can't be enabled anymore and pfmfi and the storage key |
|
interpretation are disabled. If cmma has already been enabled or the |
|
hpage module parameter is not set to 1, -EINVAL is returned. |
|
|
|
While it is generally possible to create a huge page backed VM without |
|
this capability, the VM will not be able to run. |
|
|
|
7.15 KVM_CAP_MSR_PLATFORM_INFO |
|
------------------------------ |
|
|
|
:Architectures: x86 |
|
:Parameters: args[0] whether feature should be enabled or not |
|
|
|
With this capability, a guest may read the MSR_PLATFORM_INFO MSR. Otherwise, |
|
a #GP would be raised when the guest tries to access. Currently, this |
|
capability does not enable write permissions of this MSR for the guest. |
|
|
|
7.16 KVM_CAP_PPC_NESTED_HV |
|
-------------------------- |
|
|
|
:Architectures: ppc |
|
:Parameters: none |
|
:Returns: 0 on success, -EINVAL when the implementation doesn't support |
|
nested-HV virtualization. |
|
|
|
HV-KVM on POWER9 and later systems allows for "nested-HV" |
|
virtualization, which provides a way for a guest VM to run guests that |
|
can run using the CPU's supervisor mode (privileged non-hypervisor |
|
state). Enabling this capability on a VM depends on the CPU having |
|
the necessary functionality and on the facility being enabled with a |
|
kvm-hv module parameter. |
|
|
|
7.17 KVM_CAP_EXCEPTION_PAYLOAD |
|
------------------------------ |
|
|
|
:Architectures: x86 |
|
:Parameters: args[0] whether feature should be enabled or not |
|
|
|
With this capability enabled, CR2 will not be modified prior to the |
|
emulated VM-exit when L1 intercepts a #PF exception that occurs in |
|
L2. Similarly, for kvm-intel only, DR6 will not be modified prior to |
|
the emulated VM-exit when L1 intercepts a #DB exception that occurs in |
|
L2. As a result, when KVM_GET_VCPU_EVENTS reports a pending #PF (or |
|
#DB) exception for L2, exception.has_payload will be set and the |
|
faulting address (or the new DR6 bits*) will be reported in the |
|
exception_payload field. Similarly, when userspace injects a #PF (or |
|
#DB) into L2 using KVM_SET_VCPU_EVENTS, it is expected to set |
|
exception.has_payload and to put the faulting address - or the new DR6 |
|
bits\ [#]_ - in the exception_payload field. |
|
|
|
This capability also enables exception.pending in struct |
|
kvm_vcpu_events, which allows userspace to distinguish between pending |
|
and injected exceptions. |
|
|
|
|
|
.. [#] For the new DR6 bits, note that bit 16 is set iff the #DB exception |
|
will clear DR6.RTM. |
|
|
|
7.18 KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 |
|
|
|
:Architectures: x86, arm, arm64, mips |
|
:Parameters: args[0] whether feature should be enabled or not |
|
|
|
Valid flags are:: |
|
|
|
#define KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (1 << 0) |
|
#define KVM_DIRTY_LOG_INITIALLY_SET (1 << 1) |
|
|
|
With KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE is set, KVM_GET_DIRTY_LOG will not |
|
automatically clear and write-protect all pages that are returned as dirty. |
|
Rather, userspace will have to do this operation separately using |
|
KVM_CLEAR_DIRTY_LOG. |
|
|
|
At the cost of a slightly more complicated operation, this provides better |
|
scalability and responsiveness for two reasons. First, |
|
KVM_CLEAR_DIRTY_LOG ioctl can operate on a 64-page granularity rather |
|
than requiring to sync a full memslot; this ensures that KVM does not |
|
take spinlocks for an extended period of time. Second, in some cases a |
|
large amount of time can pass between a call to KVM_GET_DIRTY_LOG and |
|
userspace actually using the data in the page. Pages can be modified |
|
during this time, which is inefficient for both the guest and userspace: |
|
the guest will incur a higher penalty due to write protection faults, |
|
while userspace can see false reports of dirty pages. Manual reprotection |
|
helps reducing this time, improving guest performance and reducing the |
|
number of dirty log false positives. |
|
|
|
With KVM_DIRTY_LOG_INITIALLY_SET set, all the bits of the dirty bitmap |
|
will be initialized to 1 when created. This also improves performance because |
|
dirty logging can be enabled gradually in small chunks on the first call |
|
to KVM_CLEAR_DIRTY_LOG. KVM_DIRTY_LOG_INITIALLY_SET depends on |
|
KVM_DIRTY_LOG_MANUAL_PROTECT_ENABLE (it is also only available on |
|
x86 and arm64 for now). |
|
|
|
KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 was previously available under the name |
|
KVM_CAP_MANUAL_DIRTY_LOG_PROTECT, but the implementation had bugs that make |
|
it hard or impossible to use it correctly. The availability of |
|
KVM_CAP_MANUAL_DIRTY_LOG_PROTECT2 signals that those bugs are fixed. |
|
Userspace should not try to use KVM_CAP_MANUAL_DIRTY_LOG_PROTECT. |
|
|
|
7.19 KVM_CAP_PPC_SECURE_GUEST |
|
------------------------------ |
|
|
|
:Architectures: ppc |
|
|
|
This capability indicates that KVM is running on a host that has |
|
ultravisor firmware and thus can support a secure guest. On such a |
|
system, a guest can ask the ultravisor to make it a secure guest, |
|
one whose memory is inaccessible to the host except for pages which |
|
are explicitly requested to be shared with the host. The ultravisor |
|
notifies KVM when a guest requests to become a secure guest, and KVM |
|
has the opportunity to veto the transition. |
|
|
|
If present, this capability can be enabled for a VM, meaning that KVM |
|
will allow the transition to secure guest mode. Otherwise KVM will |
|
veto the transition. |
|
|
|
7.20 KVM_CAP_HALT_POLL |
|
---------------------- |
|
|
|
:Architectures: all |
|
:Target: VM |
|
:Parameters: args[0] is the maximum poll time in nanoseconds |
|
:Returns: 0 on success; -1 on error |
|
|
|
This capability overrides the kvm module parameter halt_poll_ns for the |
|
target VM. |
|
|
|
VCPU polling allows a VCPU to poll for wakeup events instead of immediately |
|
scheduling during guest halts. The maximum time a VCPU can spend polling is |
|
controlled by the kvm module parameter halt_poll_ns. This capability allows |
|
the maximum halt time to specified on a per-VM basis, effectively overriding |
|
the module parameter for the target VM. |
|
|
|
7.21 KVM_CAP_X86_USER_SPACE_MSR |
|
------------------------------- |
|
|
|
:Architectures: x86 |
|
:Target: VM |
|
:Parameters: args[0] contains the mask of KVM_MSR_EXIT_REASON_* events to report |
|
:Returns: 0 on success; -1 on error |
|
|
|
This capability enables trapping of #GP invoking RDMSR and WRMSR instructions |
|
into user space. |
|
|
|
When a guest requests to read or write an MSR, KVM may not implement all MSRs |
|
that are relevant to a respective system. It also does not differentiate by |
|
CPU type. |
|
|
|
To allow more fine grained control over MSR handling, user space may enable |
|
this capability. With it enabled, MSR accesses that match the mask specified in |
|
args[0] and trigger a #GP event inside the guest by KVM will instead trigger |
|
KVM_EXIT_X86_RDMSR and KVM_EXIT_X86_WRMSR exit notifications which user space |
|
can then handle to implement model specific MSR handling and/or user notifications |
|
to inform a user that an MSR was not handled. |
|
|
|
7.22 KVM_CAP_X86_BUS_LOCK_EXIT |
|
------------------------------- |
|
|
|
:Architectures: x86 |
|
:Target: VM |
|
:Parameters: args[0] defines the policy used when bus locks detected in guest |
|
:Returns: 0 on success, -EINVAL when args[0] contains invalid bits |
|
|
|
Valid bits in args[0] are:: |
|
|
|
#define KVM_BUS_LOCK_DETECTION_OFF (1 << 0) |
|
#define KVM_BUS_LOCK_DETECTION_EXIT (1 << 1) |
|
|
|
Enabling this capability on a VM provides userspace with a way to select |
|
a policy to handle the bus locks detected in guest. Userspace can obtain |
|
the supported modes from the result of KVM_CHECK_EXTENSION and define it |
|
through the KVM_ENABLE_CAP. |
|
|
|
KVM_BUS_LOCK_DETECTION_OFF and KVM_BUS_LOCK_DETECTION_EXIT are supported |
|
currently and mutually exclusive with each other. More bits can be added in |
|
the future. |
|
|
|
With KVM_BUS_LOCK_DETECTION_OFF set, bus locks in guest will not cause vm exits |
|
so that no additional actions are needed. This is the default mode. |
|
|
|
With KVM_BUS_LOCK_DETECTION_EXIT set, vm exits happen when bus lock detected |
|
in VM. KVM just exits to userspace when handling them. Userspace can enforce |
|
its own throttling or other policy based mitigations. |
|
|
|
This capability is aimed to address the thread that VM can exploit bus locks to |
|
degree the performance of the whole system. Once the userspace enable this |
|
capability and select the KVM_BUS_LOCK_DETECTION_EXIT mode, KVM will set the |
|
KVM_RUN_BUS_LOCK flag in vcpu-run->flags field and exit to userspace. Concerning |
|
the bus lock vm exit can be preempted by a higher priority VM exit, the exit |
|
notifications to userspace can be KVM_EXIT_BUS_LOCK or other reasons. |
|
KVM_RUN_BUS_LOCK flag is used to distinguish between them. |
|
|
|
7.23 KVM_CAP_PPC_DAWR1 |
|
---------------------- |
|
|
|
:Architectures: ppc |
|
:Parameters: none |
|
:Returns: 0 on success, -EINVAL when CPU doesn't support 2nd DAWR |
|
|
|
This capability can be used to check / enable 2nd DAWR feature provided |
|
by POWER10 processor. |
|
|
|
|
|
7.24 KVM_CAP_VM_COPY_ENC_CONTEXT_FROM |
|
------------------------------------- |
|
|
|
Architectures: x86 SEV enabled |
|
Type: vm |
|
Parameters: args[0] is the fd of the source vm |
|
Returns: 0 on success; ENOTTY on error |
|
|
|
This capability enables userspace to copy encryption context from the vm |
|
indicated by the fd to the vm this is called on. |
|
|
|
This is intended to support in-guest workloads scheduled by the host. This |
|
allows the in-guest workload to maintain its own NPTs and keeps the two vms |
|
from accidentally clobbering each other with interrupts and the like (separate |
|
APIC/MSRs/etc). |
|
|
|
7.25 KVM_CAP_SGX_ATTRIBUTE |
|
-------------------------- |
|
|
|
:Architectures: x86 |
|
:Target: VM |
|
:Parameters: args[0] is a file handle of a SGX attribute file in securityfs |
|
:Returns: 0 on success, -EINVAL if the file handle is invalid or if a requested |
|
attribute is not supported by KVM. |
|
|
|
KVM_CAP_SGX_ATTRIBUTE enables a userspace VMM to grant a VM access to one or |
|
more priveleged enclave attributes. args[0] must hold a file handle to a valid |
|
SGX attribute file corresponding to an attribute that is supported/restricted |
|
by KVM (currently only PROVISIONKEY). |
|
|
|
The SGX subsystem restricts access to a subset of enclave attributes to provide |
|
additional security for an uncompromised kernel, e.g. use of the PROVISIONKEY |
|
is restricted to deter malware from using the PROVISIONKEY to obtain a stable |
|
system fingerprint. To prevent userspace from circumventing such restrictions |
|
by running an enclave in a VM, KVM prevents access to privileged attributes by |
|
default. |
|
|
|
See Documentation/x86/sgx.rst for more details. |
|
|
|
7.26 KVM_CAP_PPC_RPT_INVALIDATE |
|
------------------------------- |
|
|
|
:Capability: KVM_CAP_PPC_RPT_INVALIDATE |
|
:Architectures: ppc |
|
:Type: vm |
|
|
|
This capability indicates that the kernel is capable of handling |
|
H_RPT_INVALIDATE hcall. |
|
|
|
In order to enable the use of H_RPT_INVALIDATE in the guest, |
|
user space might have to advertise it for the guest. For example, |
|
IBM pSeries (sPAPR) guest starts using it if "hcall-rpt-invalidate" is |
|
present in the "ibm,hypertas-functions" device-tree property. |
|
|
|
This capability is enabled for hypervisors on platforms like POWER9 |
|
that support radix MMU. |
|
|
|
7.27 KVM_CAP_EXIT_ON_EMULATION_FAILURE |
|
-------------------------------------- |
|
|
|
:Architectures: x86 |
|
:Parameters: args[0] whether the feature should be enabled or not |
|
|
|
When this capability is enabled, an emulation failure will result in an exit |
|
to userspace with KVM_INTERNAL_ERROR (except when the emulator was invoked |
|
to handle a VMware backdoor instruction). Furthermore, KVM will now provide up |
|
to 15 instruction bytes for any exit to userspace resulting from an emulation |
|
failure. When these exits to userspace occur use the emulation_failure struct |
|
instead of the internal struct. They both have the same layout, but the |
|
emulation_failure struct matches the content better. It also explicitly |
|
defines the 'flags' field which is used to describe the fields in the struct |
|
that are valid (ie: if KVM_INTERNAL_ERROR_EMULATION_FLAG_INSTRUCTION_BYTES is |
|
set in the 'flags' field then both 'insn_size' and 'insn_bytes' have valid data |
|
in them.) |
|
|
|
7.28 KVM_CAP_ARM_MTE |
|
-------------------- |
|
|
|
:Architectures: arm64 |
|
:Parameters: none |
|
|
|
This capability indicates that KVM (and the hardware) supports exposing the |
|
Memory Tagging Extensions (MTE) to the guest. It must also be enabled by the |
|
VMM before creating any VCPUs to allow the guest access. Note that MTE is only |
|
available to a guest running in AArch64 mode and enabling this capability will |
|
cause attempts to create AArch32 VCPUs to fail. |
|
|
|
When enabled the guest is able to access tags associated with any memory given |
|
to the guest. KVM will ensure that the tags are maintained during swap or |
|
hibernation of the host; however the VMM needs to manually save/restore the |
|
tags as appropriate if the VM is migrated. |
|
|
|
When this capability is enabled all memory in memslots must be mapped as |
|
not-shareable (no MAP_SHARED), attempts to create a memslot with a |
|
MAP_SHARED mmap will result in an -EINVAL return. |
|
|
|
When enabled the VMM may make use of the ``KVM_ARM_MTE_COPY_TAGS`` ioctl to |
|
perform a bulk copy of tags to/from the guest. |
|
|
|
8. Other capabilities. |
|
====================== |
|
|
|
This section lists capabilities that give information about other |
|
features of the KVM implementation. |
|
|
|
8.1 KVM_CAP_PPC_HWRNG |
|
--------------------- |
|
|
|
:Architectures: ppc |
|
|
|
This capability, if KVM_CHECK_EXTENSION indicates that it is |
|
available, means that the kernel has an implementation of the |
|
H_RANDOM hypercall backed by a hardware random-number generator. |
|
If present, the kernel H_RANDOM handler can be enabled for guest use |
|
with the KVM_CAP_PPC_ENABLE_HCALL capability. |
|
|
|
8.2 KVM_CAP_HYPERV_SYNIC |
|
------------------------ |
|
|
|
:Architectures: x86 |
|
|
|
This capability, if KVM_CHECK_EXTENSION indicates that it is |
|
available, means that the kernel has an implementation of the |
|
Hyper-V Synthetic interrupt controller(SynIC). Hyper-V SynIC is |
|
used to support Windows Hyper-V based guest paravirt drivers(VMBus). |
|
|
|
In order to use SynIC, it has to be activated by setting this |
|
capability via KVM_ENABLE_CAP ioctl on the vcpu fd. Note that this |
|
will disable the use of APIC hardware virtualization even if supported |
|
by the CPU, as it's incompatible with SynIC auto-EOI behavior. |
|
|
|
8.3 KVM_CAP_PPC_RADIX_MMU |
|
------------------------- |
|
|
|
:Architectures: ppc |
|
|
|
This capability, if KVM_CHECK_EXTENSION indicates that it is |
|
available, means that the kernel can support guests using the |
|
radix MMU defined in Power ISA V3.00 (as implemented in the POWER9 |
|
processor). |
|
|
|
8.4 KVM_CAP_PPC_HASH_MMU_V3 |
|
--------------------------- |
|
|
|
:Architectures: ppc |
|
|
|
This capability, if KVM_CHECK_EXTENSION indicates that it is |
|
available, means that the kernel can support guests using the |
|
hashed page table MMU defined in Power ISA V3.00 (as implemented in |
|
the POWER9 processor), including in-memory segment tables. |
|
|
|
8.5 KVM_CAP_MIPS_VZ |
|
------------------- |
|
|
|
:Architectures: mips |
|
|
|
This capability, if KVM_CHECK_EXTENSION on the main kvm handle indicates that |
|
it is available, means that full hardware assisted virtualization capabilities |
|
of the hardware are available for use through KVM. An appropriate |
|
KVM_VM_MIPS_* type must be passed to KVM_CREATE_VM to create a VM which |
|
utilises it. |
|
|
|
If KVM_CHECK_EXTENSION on a kvm VM handle indicates that this capability is |
|
available, it means that the VM is using full hardware assisted virtualization |
|
capabilities of the hardware. This is useful to check after creating a VM with |
|
KVM_VM_MIPS_DEFAULT. |
|
|
|
The value returned by KVM_CHECK_EXTENSION should be compared against known |
|
values (see below). All other values are reserved. This is to allow for the |
|
possibility of other hardware assisted virtualization implementations which |
|
may be incompatible with the MIPS VZ ASE. |
|
|
|
== ========================================================================== |
|
0 The trap & emulate implementation is in use to run guest code in user |
|
mode. Guest virtual memory segments are rearranged to fit the guest in the |
|
user mode address space. |
|
|
|
1 The MIPS VZ ASE is in use, providing full hardware assisted |
|
virtualization, including standard guest virtual memory segments. |
|
== ========================================================================== |
|
|
|
8.6 KVM_CAP_MIPS_TE |
|
------------------- |
|
|
|
:Architectures: mips |
|
|
|
This capability, if KVM_CHECK_EXTENSION on the main kvm handle indicates that |
|
it is available, means that the trap & emulate implementation is available to |
|
run guest code in user mode, even if KVM_CAP_MIPS_VZ indicates that hardware |
|
assisted virtualisation is also available. KVM_VM_MIPS_TE (0) must be passed |
|
to KVM_CREATE_VM to create a VM which utilises it. |
|
|
|
If KVM_CHECK_EXTENSION on a kvm VM handle indicates that this capability is |
|
available, it means that the VM is using trap & emulate. |
|
|
|
8.7 KVM_CAP_MIPS_64BIT |
|
---------------------- |
|
|
|
:Architectures: mips |
|
|
|
This capability indicates the supported architecture type of the guest, i.e. the |
|
supported register and address width. |
|
|
|
The values returned when this capability is checked by KVM_CHECK_EXTENSION on a |
|
kvm VM handle correspond roughly to the CP0_Config.AT register field, and should |
|
be checked specifically against known values (see below). All other values are |
|
reserved. |
|
|
|
== ======================================================================== |
|
0 MIPS32 or microMIPS32. |
|
Both registers and addresses are 32-bits wide. |
|
It will only be possible to run 32-bit guest code. |
|
|
|
1 MIPS64 or microMIPS64 with access only to 32-bit compatibility segments. |
|
Registers are 64-bits wide, but addresses are 32-bits wide. |
|
64-bit guest code may run but cannot access MIPS64 memory segments. |
|
It will also be possible to run 32-bit guest code. |
|
|
|
2 MIPS64 or microMIPS64 with access to all address segments. |
|
Both registers and addresses are 64-bits wide. |
|
It will be possible to run 64-bit or 32-bit guest code. |
|
== ======================================================================== |
|
|
|
8.9 KVM_CAP_ARM_USER_IRQ |
|
------------------------ |
|
|
|
:Architectures: arm, arm64 |
|
|
|
This capability, if KVM_CHECK_EXTENSION indicates that it is available, means |
|
that if userspace creates a VM without an in-kernel interrupt controller, it |
|
will be notified of changes to the output level of in-kernel emulated devices, |
|
which can generate virtual interrupts, presented to the VM. |
|
For such VMs, on every return to userspace, the kernel |
|
updates the vcpu's run->s.regs.device_irq_level field to represent the actual |
|
output level of the device. |
|
|
|
Whenever kvm detects a change in the device output level, kvm guarantees at |
|
least one return to userspace before running the VM. This exit could either |
|
be a KVM_EXIT_INTR or any other exit event, like KVM_EXIT_MMIO. This way, |
|
userspace can always sample the device output level and re-compute the state of |
|
the userspace interrupt controller. Userspace should always check the state |
|
of run->s.regs.device_irq_level on every kvm exit. |
|
The value in run->s.regs.device_irq_level can represent both level and edge |
|
triggered interrupt signals, depending on the device. Edge triggered interrupt |
|
signals will exit to userspace with the bit in run->s.regs.device_irq_level |
|
set exactly once per edge signal. |
|
|
|
The field run->s.regs.device_irq_level is available independent of |
|
run->kvm_valid_regs or run->kvm_dirty_regs bits. |
|
|
|
If KVM_CAP_ARM_USER_IRQ is supported, the KVM_CHECK_EXTENSION ioctl returns a |
|
number larger than 0 indicating the version of this capability is implemented |
|
and thereby which bits in run->s.regs.device_irq_level can signal values. |
|
|
|
Currently the following bits are defined for the device_irq_level bitmap:: |
|
|
|
KVM_CAP_ARM_USER_IRQ >= 1: |
|
|
|
KVM_ARM_DEV_EL1_VTIMER - EL1 virtual timer |
|
KVM_ARM_DEV_EL1_PTIMER - EL1 physical timer |
|
KVM_ARM_DEV_PMU - ARM PMU overflow interrupt signal |
|
|
|
Future versions of kvm may implement additional events. These will get |
|
indicated by returning a higher number from KVM_CHECK_EXTENSION and will be |
|
listed above. |
|
|
|
8.10 KVM_CAP_PPC_SMT_POSSIBLE |
|
----------------------------- |
|
|
|
:Architectures: ppc |
|
|
|
Querying this capability returns a bitmap indicating the possible |
|
virtual SMT modes that can be set using KVM_CAP_PPC_SMT. If bit N |
|
(counting from the right) is set, then a virtual SMT mode of 2^N is |
|
available. |
|
|
|
8.11 KVM_CAP_HYPERV_SYNIC2 |
|
-------------------------- |
|
|
|
:Architectures: x86 |
|
|
|
This capability enables a newer version of Hyper-V Synthetic interrupt |
|
controller (SynIC). The only difference with KVM_CAP_HYPERV_SYNIC is that KVM |
|
doesn't clear SynIC message and event flags pages when they are enabled by |
|
writing to the respective MSRs. |
|
|
|
8.12 KVM_CAP_HYPERV_VP_INDEX |
|
---------------------------- |
|
|
|
:Architectures: x86 |
|
|
|
This capability indicates that userspace can load HV_X64_MSR_VP_INDEX msr. Its |
|
value is used to denote the target vcpu for a SynIC interrupt. For |
|
compatibilty, KVM initializes this msr to KVM's internal vcpu index. When this |
|
capability is absent, userspace can still query this msr's value. |
|
|
|
8.13 KVM_CAP_S390_AIS_MIGRATION |
|
------------------------------- |
|
|
|
:Architectures: s390 |
|
:Parameters: none |
|
|
|
This capability indicates if the flic device will be able to get/set the |
|
AIS states for migration via the KVM_DEV_FLIC_AISM_ALL attribute and allows |
|
to discover this without having to create a flic device. |
|
|
|
8.14 KVM_CAP_S390_PSW |
|
--------------------- |
|
|
|
:Architectures: s390 |
|
|
|
This capability indicates that the PSW is exposed via the kvm_run structure. |
|
|
|
8.15 KVM_CAP_S390_GMAP |
|
---------------------- |
|
|
|
:Architectures: s390 |
|
|
|
This capability indicates that the user space memory used as guest mapping can |
|
be anywhere in the user memory address space, as long as the memory slots are |
|
aligned and sized to a segment (1MB) boundary. |
|
|
|
8.16 KVM_CAP_S390_COW |
|
--------------------- |
|
|
|
:Architectures: s390 |
|
|
|
This capability indicates that the user space memory used as guest mapping can |
|
use copy-on-write semantics as well as dirty pages tracking via read-only page |
|
tables. |
|
|
|
8.17 KVM_CAP_S390_BPB |
|
--------------------- |
|
|
|
:Architectures: s390 |
|
|
|
This capability indicates that kvm will implement the interfaces to handle |
|
reset, migration and nested KVM for branch prediction blocking. The stfle |
|
facility 82 should not be provided to the guest without this capability. |
|
|
|
8.18 KVM_CAP_HYPERV_TLBFLUSH |
|
---------------------------- |
|
|
|
:Architectures: x86 |
|
|
|
This capability indicates that KVM supports paravirtualized Hyper-V TLB Flush |
|
hypercalls: |
|
HvFlushVirtualAddressSpace, HvFlushVirtualAddressSpaceEx, |
|
HvFlushVirtualAddressList, HvFlushVirtualAddressListEx. |
|
|
|
8.19 KVM_CAP_ARM_INJECT_SERROR_ESR |
|
---------------------------------- |
|
|
|
:Architectures: arm, arm64 |
|
|
|
This capability indicates that userspace can specify (via the |
|
KVM_SET_VCPU_EVENTS ioctl) the syndrome value reported to the guest when it |
|
takes a virtual SError interrupt exception. |
|
If KVM advertises this capability, userspace can only specify the ISS field for |
|
the ESR syndrome. Other parts of the ESR, such as the EC are generated by the |
|
CPU when the exception is taken. If this virtual SError is taken to EL1 using |
|
AArch64, this value will be reported in the ISS field of ESR_ELx. |
|
|
|
See KVM_CAP_VCPU_EVENTS for more details. |
|
|
|
8.20 KVM_CAP_HYPERV_SEND_IPI |
|
---------------------------- |
|
|
|
:Architectures: x86 |
|
|
|
This capability indicates that KVM supports paravirtualized Hyper-V IPI send |
|
hypercalls: |
|
HvCallSendSyntheticClusterIpi, HvCallSendSyntheticClusterIpiEx. |
|
|
|
8.21 KVM_CAP_HYPERV_DIRECT_TLBFLUSH |
|
----------------------------------- |
|
|
|
:Architectures: x86 |
|
|
|
This capability indicates that KVM running on top of Hyper-V hypervisor |
|
enables Direct TLB flush for its guests meaning that TLB flush |
|
hypercalls are handled by Level 0 hypervisor (Hyper-V) bypassing KVM. |
|
Due to the different ABI for hypercall parameters between Hyper-V and |
|
KVM, enabling this capability effectively disables all hypercall |
|
handling by KVM (as some KVM hypercall may be mistakenly treated as TLB |
|
flush hypercalls by Hyper-V) so userspace should disable KVM identification |
|
in CPUID and only exposes Hyper-V identification. In this case, guest |
|
thinks it's running on Hyper-V and only use Hyper-V hypercalls. |
|
|
|
8.22 KVM_CAP_S390_VCPU_RESETS |
|
----------------------------- |
|
|
|
:Architectures: s390 |
|
|
|
This capability indicates that the KVM_S390_NORMAL_RESET and |
|
KVM_S390_CLEAR_RESET ioctls are available. |
|
|
|
8.23 KVM_CAP_S390_PROTECTED |
|
--------------------------- |
|
|
|
:Architectures: s390 |
|
|
|
This capability indicates that the Ultravisor has been initialized and |
|
KVM can therefore start protected VMs. |
|
This capability governs the KVM_S390_PV_COMMAND ioctl and the |
|
KVM_MP_STATE_LOAD MP_STATE. KVM_SET_MP_STATE can fail for protected |
|
guests when the state change is invalid. |
|
|
|
8.24 KVM_CAP_STEAL_TIME |
|
----------------------- |
|
|
|
:Architectures: arm64, x86 |
|
|
|
This capability indicates that KVM supports steal time accounting. |
|
When steal time accounting is supported it may be enabled with |
|
architecture-specific interfaces. This capability and the architecture- |
|
specific interfaces must be consistent, i.e. if one says the feature |
|
is supported, than the other should as well and vice versa. For arm64 |
|
see Documentation/virt/kvm/devices/vcpu.rst "KVM_ARM_VCPU_PVTIME_CTRL". |
|
For x86 see Documentation/virt/kvm/msr.rst "MSR_KVM_STEAL_TIME". |
|
|
|
8.25 KVM_CAP_S390_DIAG318 |
|
------------------------- |
|
|
|
:Architectures: s390 |
|
|
|
This capability enables a guest to set information about its control program |
|
(i.e. guest kernel type and version). The information is helpful during |
|
system/firmware service events, providing additional data about the guest |
|
environments running on the machine. |
|
|
|
The information is associated with the DIAGNOSE 0x318 instruction, which sets |
|
an 8-byte value consisting of a one-byte Control Program Name Code (CPNC) and |
|
a 7-byte Control Program Version Code (CPVC). The CPNC determines what |
|
environment the control program is running in (e.g. Linux, z/VM...), and the |
|
CPVC is used for information specific to OS (e.g. Linux version, Linux |
|
distribution...) |
|
|
|
If this capability is available, then the CPNC and CPVC can be synchronized |
|
between KVM and userspace via the sync regs mechanism (KVM_SYNC_DIAG318). |
|
|
|
8.26 KVM_CAP_X86_USER_SPACE_MSR |
|
------------------------------- |
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:Architectures: x86 |
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This capability indicates that KVM supports deflection of MSR reads and |
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writes to user space. It can be enabled on a VM level. If enabled, MSR |
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accesses that would usually trigger a #GP by KVM into the guest will |
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instead get bounced to user space through the KVM_EXIT_X86_RDMSR and |
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KVM_EXIT_X86_WRMSR exit notifications. |
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8.27 KVM_CAP_X86_MSR_FILTER |
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--------------------------- |
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:Architectures: x86 |
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This capability indicates that KVM supports that accesses to user defined MSRs |
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may be rejected. With this capability exposed, KVM exports new VM ioctl |
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KVM_X86_SET_MSR_FILTER which user space can call to specify bitmaps of MSR |
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ranges that KVM should reject access to. |
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In combination with KVM_CAP_X86_USER_SPACE_MSR, this allows user space to |
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trap and emulate MSRs that are outside of the scope of KVM as well as |
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limit the attack surface on KVM's MSR emulation code. |
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8.28 KVM_CAP_ENFORCE_PV_FEATURE_CPUID |
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----------------------------- |
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Architectures: x86 |
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When enabled, KVM will disable paravirtual features provided to the |
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guest according to the bits in the KVM_CPUID_FEATURES CPUID leaf |
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(0x40000001). Otherwise, a guest may use the paravirtual features |
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regardless of what has actually been exposed through the CPUID leaf. |
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8.29 KVM_CAP_DIRTY_LOG_RING |
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--------------------------- |
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:Architectures: x86 |
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:Parameters: args[0] - size of the dirty log ring |
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KVM is capable of tracking dirty memory using ring buffers that are |
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mmaped into userspace; there is one dirty ring per vcpu. |
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The dirty ring is available to userspace as an array of |
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``struct kvm_dirty_gfn``. Each dirty entry it's defined as:: |
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struct kvm_dirty_gfn { |
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__u32 flags; |
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__u32 slot; /* as_id | slot_id */ |
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__u64 offset; |
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}; |
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The following values are defined for the flags field to define the |
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current state of the entry:: |
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#define KVM_DIRTY_GFN_F_DIRTY BIT(0) |
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#define KVM_DIRTY_GFN_F_RESET BIT(1) |
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#define KVM_DIRTY_GFN_F_MASK 0x3 |
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Userspace should call KVM_ENABLE_CAP ioctl right after KVM_CREATE_VM |
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ioctl to enable this capability for the new guest and set the size of |
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the rings. Enabling the capability is only allowed before creating any |
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vCPU, and the size of the ring must be a power of two. The larger the |
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ring buffer, the less likely the ring is full and the VM is forced to |
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exit to userspace. The optimal size depends on the workload, but it is |
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recommended that it be at least 64 KiB (4096 entries). |
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Just like for dirty page bitmaps, the buffer tracks writes to |
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all user memory regions for which the KVM_MEM_LOG_DIRTY_PAGES flag was |
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set in KVM_SET_USER_MEMORY_REGION. Once a memory region is registered |
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with the flag set, userspace can start harvesting dirty pages from the |
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ring buffer. |
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An entry in the ring buffer can be unused (flag bits ``00``), |
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dirty (flag bits ``01``) or harvested (flag bits ``1X``). The |
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state machine for the entry is as follows:: |
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dirtied harvested reset |
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00 -----------> 01 -------------> 1X -------+ |
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^ | |
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| | |
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+------------------------------------------+ |
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To harvest the dirty pages, userspace accesses the mmaped ring buffer |
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to read the dirty GFNs. If the flags has the DIRTY bit set (at this stage |
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the RESET bit must be cleared), then it means this GFN is a dirty GFN. |
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The userspace should harvest this GFN and mark the flags from state |
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``01b`` to ``1Xb`` (bit 0 will be ignored by KVM, but bit 1 must be set |
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to show that this GFN is harvested and waiting for a reset), and move |
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on to the next GFN. The userspace should continue to do this until the |
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flags of a GFN have the DIRTY bit cleared, meaning that it has harvested |
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all the dirty GFNs that were available. |
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It's not necessary for userspace to harvest the all dirty GFNs at once. |
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However it must collect the dirty GFNs in sequence, i.e., the userspace |
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program cannot skip one dirty GFN to collect the one next to it. |
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After processing one or more entries in the ring buffer, userspace |
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calls the VM ioctl KVM_RESET_DIRTY_RINGS to notify the kernel about |
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it, so that the kernel will reprotect those collected GFNs. |
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Therefore, the ioctl must be called *before* reading the content of |
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the dirty pages. |
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The dirty ring can get full. When it happens, the KVM_RUN of the |
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vcpu will return with exit reason KVM_EXIT_DIRTY_LOG_FULL. |
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The dirty ring interface has a major difference comparing to the |
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KVM_GET_DIRTY_LOG interface in that, when reading the dirty ring from |
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userspace, it's still possible that the kernel has not yet flushed the |
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processor's dirty page buffers into the kernel buffer (with dirty bitmaps, the |
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flushing is done by the KVM_GET_DIRTY_LOG ioctl). To achieve that, one |
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needs to kick the vcpu out of KVM_RUN using a signal. The resulting |
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vmexit ensures that all dirty GFNs are flushed to the dirty rings. |
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NOTE: the capability KVM_CAP_DIRTY_LOG_RING and the corresponding |
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ioctl KVM_RESET_DIRTY_RINGS are mutual exclusive to the existing ioctls |
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KVM_GET_DIRTY_LOG and KVM_CLEAR_DIRTY_LOG. After enabling |
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KVM_CAP_DIRTY_LOG_RING with an acceptable dirty ring size, the virtual |
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machine will switch to ring-buffer dirty page tracking and further |
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KVM_GET_DIRTY_LOG or KVM_CLEAR_DIRTY_LOG ioctls will fail. |
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8.30 KVM_CAP_XEN_HVM |
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-------------------- |
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:Architectures: x86 |
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This capability indicates the features that Xen supports for hosting Xen |
|
PVHVM guests. Valid flags are:: |
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#define KVM_XEN_HVM_CONFIG_HYPERCALL_MSR (1 << 0) |
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#define KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL (1 << 1) |
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#define KVM_XEN_HVM_CONFIG_SHARED_INFO (1 << 2) |
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#define KVM_XEN_HVM_CONFIG_RUNSTATE (1 << 2) |
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The KVM_XEN_HVM_CONFIG_HYPERCALL_MSR flag indicates that the KVM_XEN_HVM_CONFIG |
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ioctl is available, for the guest to set its hypercall page. |
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If KVM_XEN_HVM_CONFIG_INTERCEPT_HCALL is also set, the same flag may also be |
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provided in the flags to KVM_XEN_HVM_CONFIG, without providing hypercall page |
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contents, to request that KVM generate hypercall page content automatically |
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and also enable interception of guest hypercalls with KVM_EXIT_XEN. |
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The KVM_XEN_HVM_CONFIG_SHARED_INFO flag indicates the availability of the |
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KVM_XEN_HVM_SET_ATTR, KVM_XEN_HVM_GET_ATTR, KVM_XEN_VCPU_SET_ATTR and |
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KVM_XEN_VCPU_GET_ATTR ioctls, as well as the delivery of exception vectors |
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for event channel upcalls when the evtchn_upcall_pending field of a vcpu's |
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vcpu_info is set. |
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The KVM_XEN_HVM_CONFIG_RUNSTATE flag indicates that the runstate-related |
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features KVM_XEN_VCPU_ATTR_TYPE_RUNSTATE_ADDR/_CURRENT/_DATA/_ADJUST are |
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supported by the KVM_XEN_VCPU_SET_ATTR/KVM_XEN_VCPU_GET_ATTR ioctls. |
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8.31 KVM_CAP_PPC_MULTITCE |
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------------------------- |
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:Capability: KVM_CAP_PPC_MULTITCE |
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:Architectures: ppc |
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:Type: vm |
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|
This capability means the kernel is capable of handling hypercalls |
|
H_PUT_TCE_INDIRECT and H_STUFF_TCE without passing those into the user |
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space. This significantly accelerates DMA operations for PPC KVM guests. |
|
User space should expect that its handlers for these hypercalls |
|
are not going to be called if user space previously registered LIOBN |
|
in KVM (via KVM_CREATE_SPAPR_TCE or similar calls). |
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In order to enable H_PUT_TCE_INDIRECT and H_STUFF_TCE use in the guest, |
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user space might have to advertise it for the guest. For example, |
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IBM pSeries (sPAPR) guest starts using them if "hcall-multi-tce" is |
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present in the "ibm,hypertas-functions" device-tree property. |
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|
The hypercalls mentioned above may or may not be processed successfully |
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in the kernel based fast path. If they can not be handled by the kernel, |
|
they will get passed on to user space. So user space still has to have |
|
an implementation for these despite the in kernel acceleration. |
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|
This capability is always enabled. |
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8.32 KVM_CAP_PTP_KVM |
|
-------------------- |
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|
|
:Architectures: arm64 |
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|
This capability indicates that the KVM virtual PTP service is |
|
supported in the host. A VMM can check whether the service is |
|
available to the guest on migration. |
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8.33 KVM_CAP_HYPERV_ENFORCE_CPUID |
|
----------------------------- |
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|
Architectures: x86 |
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|
|
When enabled, KVM will disable emulated Hyper-V features provided to the |
|
guest according to the bits Hyper-V CPUID feature leaves. Otherwise, all |
|
currently implmented Hyper-V features are provided unconditionally when |
|
Hyper-V identification is set in the HYPERV_CPUID_INTERFACE (0x40000001) |
|
leaf. |
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|
8.34 KVM_CAP_EXIT_HYPERCALL |
|
--------------------------- |
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|
|
:Capability: KVM_CAP_EXIT_HYPERCALL |
|
:Architectures: x86 |
|
:Type: vm |
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|
|
This capability, if enabled, will cause KVM to exit to userspace |
|
with KVM_EXIT_HYPERCALL exit reason to process some hypercalls. |
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|
|
Calling KVM_CHECK_EXTENSION for this capability will return a bitmask |
|
of hypercalls that can be configured to exit to userspace. |
|
Right now, the only such hypercall is KVM_HC_MAP_GPA_RANGE. |
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|
The argument to KVM_ENABLE_CAP is also a bitmask, and must be a subset |
|
of the result of KVM_CHECK_EXTENSION. KVM will forward to userspace |
|
the hypercalls whose corresponding bit is in the argument, and return |
|
ENOSYS for the others.
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