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118 lines
2.9 KiB
118 lines
2.9 KiB
// SPDX-License-Identifier: GPL-2.0 |
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/* |
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* Copyright (C) 2019 Western Digital Corporation or its affiliates. |
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* |
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* Authors: |
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* Anup Patel <[email protected]> |
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*/ |
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#include <linux/bitops.h> |
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#include <linux/cpumask.h> |
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#include <linux/errno.h> |
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#include <linux/err.h> |
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#include <linux/module.h> |
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#include <linux/kvm_host.h> |
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#include <asm/csr.h> |
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#include <asm/sbi.h> |
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static unsigned long vmid_version = 1; |
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static unsigned long vmid_next; |
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static unsigned long vmid_bits; |
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static DEFINE_SPINLOCK(vmid_lock); |
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void kvm_riscv_stage2_vmid_detect(void) |
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{ |
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unsigned long old; |
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/* Figure-out number of VMID bits in HW */ |
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old = csr_read(CSR_HGATP); |
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csr_write(CSR_HGATP, old | HGATP_VMID_MASK); |
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vmid_bits = csr_read(CSR_HGATP); |
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vmid_bits = (vmid_bits & HGATP_VMID_MASK) >> HGATP_VMID_SHIFT; |
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vmid_bits = fls_long(vmid_bits); |
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csr_write(CSR_HGATP, old); |
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/* We polluted local TLB so flush all guest TLB */ |
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__kvm_riscv_hfence_gvma_all(); |
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/* We don't use VMID bits if they are not sufficient */ |
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if ((1UL << vmid_bits) < num_possible_cpus()) |
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vmid_bits = 0; |
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} |
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unsigned long kvm_riscv_stage2_vmid_bits(void) |
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{ |
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return vmid_bits; |
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} |
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int kvm_riscv_stage2_vmid_init(struct kvm *kvm) |
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{ |
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/* Mark the initial VMID and VMID version invalid */ |
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kvm->arch.vmid.vmid_version = 0; |
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kvm->arch.vmid.vmid = 0; |
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return 0; |
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} |
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bool kvm_riscv_stage2_vmid_ver_changed(struct kvm_vmid *vmid) |
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{ |
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if (!vmid_bits) |
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return false; |
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return unlikely(READ_ONCE(vmid->vmid_version) != |
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READ_ONCE(vmid_version)); |
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} |
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void kvm_riscv_stage2_vmid_update(struct kvm_vcpu *vcpu) |
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{ |
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unsigned long i; |
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struct kvm_vcpu *v; |
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struct kvm_vmid *vmid = &vcpu->kvm->arch.vmid; |
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if (!kvm_riscv_stage2_vmid_ver_changed(vmid)) |
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return; |
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spin_lock(&vmid_lock); |
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/* |
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* We need to re-check the vmid_version here to ensure that if |
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* another vcpu already allocated a valid vmid for this vm. |
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*/ |
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if (!kvm_riscv_stage2_vmid_ver_changed(vmid)) { |
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spin_unlock(&vmid_lock); |
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return; |
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} |
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/* First user of a new VMID version? */ |
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if (unlikely(vmid_next == 0)) { |
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WRITE_ONCE(vmid_version, READ_ONCE(vmid_version) + 1); |
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vmid_next = 1; |
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/* |
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* We ran out of VMIDs so we increment vmid_version and |
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* start assigning VMIDs from 1. |
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* |
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* This also means existing VMIDs assignement to all Guest |
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* instances is invalid and we have force VMID re-assignement |
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* for all Guest instances. The Guest instances that were not |
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* running will automatically pick-up new VMIDs because will |
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* call kvm_riscv_stage2_vmid_update() whenever they enter |
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* in-kernel run loop. For Guest instances that are already |
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* running, we force VM exits on all host CPUs using IPI and |
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* flush all Guest TLBs. |
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*/ |
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sbi_remote_hfence_gvma(cpu_online_mask, 0, 0); |
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} |
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vmid->vmid = vmid_next; |
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vmid_next++; |
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vmid_next &= (1 << vmid_bits) - 1; |
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WRITE_ONCE(vmid->vmid_version, READ_ONCE(vmid_version)); |
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spin_unlock(&vmid_lock); |
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/* Request stage2 page table update for all VCPUs */ |
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kvm_for_each_vcpu(i, v, vcpu->kvm) |
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kvm_make_request(KVM_REQ_UPDATE_HGATP, v); |
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}
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