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561 lines
15 KiB
561 lines
15 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* X86 specific Hyper-V initialization code. |
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* |
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* Copyright (C) 2016, Microsoft, Inc. |
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* |
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* Author : K. Y. Srinivasan <[email protected]> |
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*/ |
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#include <linux/efi.h> |
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#include <linux/types.h> |
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#include <linux/bitfield.h> |
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#include <linux/io.h> |
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#include <asm/apic.h> |
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#include <asm/desc.h> |
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#include <asm/hypervisor.h> |
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#include <asm/hyperv-tlfs.h> |
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#include <asm/mshyperv.h> |
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#include <asm/idtentry.h> |
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#include <linux/kexec.h> |
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#include <linux/version.h> |
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#include <linux/vmalloc.h> |
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#include <linux/mm.h> |
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#include <linux/hyperv.h> |
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#include <linux/slab.h> |
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#include <linux/kernel.h> |
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#include <linux/cpuhotplug.h> |
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#include <linux/syscore_ops.h> |
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#include <clocksource/hyperv_timer.h> |
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#include <linux/highmem.h> |
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int hyperv_init_cpuhp; |
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u64 hv_current_partition_id = ~0ull; |
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EXPORT_SYMBOL_GPL(hv_current_partition_id); |
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void *hv_hypercall_pg; |
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EXPORT_SYMBOL_GPL(hv_hypercall_pg); |
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/* Storage to save the hypercall page temporarily for hibernation */ |
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static void *hv_hypercall_pg_saved; |
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struct hv_vp_assist_page **hv_vp_assist_page; |
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EXPORT_SYMBOL_GPL(hv_vp_assist_page); |
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static int hv_cpu_init(unsigned int cpu) |
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{ |
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union hv_vp_assist_msr_contents msr = { 0 }; |
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struct hv_vp_assist_page **hvp = &hv_vp_assist_page[smp_processor_id()]; |
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int ret; |
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ret = hv_common_cpu_init(cpu); |
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if (ret) |
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return ret; |
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if (!hv_vp_assist_page) |
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return 0; |
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if (!*hvp) { |
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if (hv_root_partition) { |
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/* |
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* For root partition we get the hypervisor provided VP assist |
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* page, instead of allocating a new page. |
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*/ |
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rdmsrl(HV_X64_MSR_VP_ASSIST_PAGE, msr.as_uint64); |
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*hvp = memremap(msr.pfn << |
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HV_X64_MSR_VP_ASSIST_PAGE_ADDRESS_SHIFT, |
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PAGE_SIZE, MEMREMAP_WB); |
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} else { |
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/* |
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* The VP assist page is an "overlay" page (see Hyper-V TLFS's |
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* Section 5.2.1 "GPA Overlay Pages"). Here it must be zeroed |
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* out to make sure we always write the EOI MSR in |
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* hv_apic_eoi_write() *after* the EOI optimization is disabled |
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* in hv_cpu_die(), otherwise a CPU may not be stopped in the |
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* case of CPU offlining and the VM will hang. |
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*/ |
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*hvp = __vmalloc(PAGE_SIZE, GFP_KERNEL | __GFP_ZERO); |
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if (*hvp) |
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msr.pfn = vmalloc_to_pfn(*hvp); |
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} |
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WARN_ON(!(*hvp)); |
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if (*hvp) { |
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msr.enable = 1; |
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wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, msr.as_uint64); |
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} |
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} |
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return 0; |
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} |
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static void (*hv_reenlightenment_cb)(void); |
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static void hv_reenlightenment_notify(struct work_struct *dummy) |
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{ |
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struct hv_tsc_emulation_status emu_status; |
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rdmsrl(HV_X64_MSR_TSC_EMULATION_STATUS, *(u64 *)&emu_status); |
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/* Don't issue the callback if TSC accesses are not emulated */ |
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if (hv_reenlightenment_cb && emu_status.inprogress) |
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hv_reenlightenment_cb(); |
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} |
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static DECLARE_DELAYED_WORK(hv_reenlightenment_work, hv_reenlightenment_notify); |
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void hyperv_stop_tsc_emulation(void) |
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{ |
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u64 freq; |
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struct hv_tsc_emulation_status emu_status; |
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rdmsrl(HV_X64_MSR_TSC_EMULATION_STATUS, *(u64 *)&emu_status); |
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emu_status.inprogress = 0; |
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wrmsrl(HV_X64_MSR_TSC_EMULATION_STATUS, *(u64 *)&emu_status); |
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rdmsrl(HV_X64_MSR_TSC_FREQUENCY, freq); |
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tsc_khz = div64_u64(freq, 1000); |
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} |
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EXPORT_SYMBOL_GPL(hyperv_stop_tsc_emulation); |
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static inline bool hv_reenlightenment_available(void) |
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{ |
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/* |
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* Check for required features and privileges to make TSC frequency |
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* change notifications work. |
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*/ |
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return ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS && |
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ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE && |
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ms_hyperv.features & HV_ACCESS_REENLIGHTENMENT; |
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} |
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DEFINE_IDTENTRY_SYSVEC(sysvec_hyperv_reenlightenment) |
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{ |
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ack_APIC_irq(); |
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inc_irq_stat(irq_hv_reenlightenment_count); |
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schedule_delayed_work(&hv_reenlightenment_work, HZ/10); |
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} |
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void set_hv_tscchange_cb(void (*cb)(void)) |
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{ |
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struct hv_reenlightenment_control re_ctrl = { |
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.vector = HYPERV_REENLIGHTENMENT_VECTOR, |
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.enabled = 1, |
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.target_vp = hv_vp_index[smp_processor_id()] |
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}; |
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struct hv_tsc_emulation_control emu_ctrl = {.enabled = 1}; |
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if (!hv_reenlightenment_available()) { |
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pr_warn("Hyper-V: reenlightenment support is unavailable\n"); |
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return; |
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} |
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hv_reenlightenment_cb = cb; |
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/* Make sure callback is registered before we write to MSRs */ |
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wmb(); |
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wrmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *((u64 *)&re_ctrl)); |
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wrmsrl(HV_X64_MSR_TSC_EMULATION_CONTROL, *((u64 *)&emu_ctrl)); |
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} |
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EXPORT_SYMBOL_GPL(set_hv_tscchange_cb); |
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void clear_hv_tscchange_cb(void) |
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{ |
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struct hv_reenlightenment_control re_ctrl; |
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if (!hv_reenlightenment_available()) |
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return; |
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rdmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *(u64 *)&re_ctrl); |
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re_ctrl.enabled = 0; |
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wrmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *(u64 *)&re_ctrl); |
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hv_reenlightenment_cb = NULL; |
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} |
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EXPORT_SYMBOL_GPL(clear_hv_tscchange_cb); |
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static int hv_cpu_die(unsigned int cpu) |
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{ |
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struct hv_reenlightenment_control re_ctrl; |
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unsigned int new_cpu; |
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hv_common_cpu_die(cpu); |
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if (hv_vp_assist_page && hv_vp_assist_page[cpu]) { |
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union hv_vp_assist_msr_contents msr = { 0 }; |
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if (hv_root_partition) { |
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/* |
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* For root partition the VP assist page is mapped to |
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* hypervisor provided page, and thus we unmap the |
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* page here and nullify it, so that in future we have |
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* correct page address mapped in hv_cpu_init. |
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*/ |
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memunmap(hv_vp_assist_page[cpu]); |
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hv_vp_assist_page[cpu] = NULL; |
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rdmsrl(HV_X64_MSR_VP_ASSIST_PAGE, msr.as_uint64); |
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msr.enable = 0; |
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} |
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wrmsrl(HV_X64_MSR_VP_ASSIST_PAGE, msr.as_uint64); |
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} |
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if (hv_reenlightenment_cb == NULL) |
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return 0; |
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rdmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *((u64 *)&re_ctrl)); |
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if (re_ctrl.target_vp == hv_vp_index[cpu]) { |
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/* |
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* Reassign reenlightenment notifications to some other online |
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* CPU or just disable the feature if there are no online CPUs |
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* left (happens on hibernation). |
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*/ |
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new_cpu = cpumask_any_but(cpu_online_mask, cpu); |
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if (new_cpu < nr_cpu_ids) |
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re_ctrl.target_vp = hv_vp_index[new_cpu]; |
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else |
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re_ctrl.enabled = 0; |
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wrmsrl(HV_X64_MSR_REENLIGHTENMENT_CONTROL, *((u64 *)&re_ctrl)); |
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} |
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return 0; |
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} |
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static int __init hv_pci_init(void) |
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{ |
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int gen2vm = efi_enabled(EFI_BOOT); |
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/* |
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* For Generation-2 VM, we exit from pci_arch_init() by returning 0. |
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* The purpose is to suppress the harmless warning: |
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* "PCI: Fatal: No config space access function found" |
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*/ |
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if (gen2vm) |
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return 0; |
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/* For Generation-1 VM, we'll proceed in pci_arch_init(). */ |
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return 1; |
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} |
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static int hv_suspend(void) |
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{ |
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union hv_x64_msr_hypercall_contents hypercall_msr; |
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int ret; |
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if (hv_root_partition) |
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return -EPERM; |
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/* |
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* Reset the hypercall page as it is going to be invalidated |
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* across hibernation. Setting hv_hypercall_pg to NULL ensures |
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* that any subsequent hypercall operation fails safely instead of |
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* crashing due to an access of an invalid page. The hypercall page |
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* pointer is restored on resume. |
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*/ |
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hv_hypercall_pg_saved = hv_hypercall_pg; |
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hv_hypercall_pg = NULL; |
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/* Disable the hypercall page in the hypervisor */ |
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rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); |
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hypercall_msr.enable = 0; |
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wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); |
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ret = hv_cpu_die(0); |
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return ret; |
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} |
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static void hv_resume(void) |
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{ |
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union hv_x64_msr_hypercall_contents hypercall_msr; |
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int ret; |
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ret = hv_cpu_init(0); |
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WARN_ON(ret); |
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/* Re-enable the hypercall page */ |
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rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); |
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hypercall_msr.enable = 1; |
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hypercall_msr.guest_physical_address = |
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vmalloc_to_pfn(hv_hypercall_pg_saved); |
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wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); |
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hv_hypercall_pg = hv_hypercall_pg_saved; |
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hv_hypercall_pg_saved = NULL; |
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/* |
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* Reenlightenment notifications are disabled by hv_cpu_die(0), |
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* reenable them here if hv_reenlightenment_cb was previously set. |
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*/ |
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if (hv_reenlightenment_cb) |
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set_hv_tscchange_cb(hv_reenlightenment_cb); |
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} |
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/* Note: when the ops are called, only CPU0 is online and IRQs are disabled. */ |
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static struct syscore_ops hv_syscore_ops = { |
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.suspend = hv_suspend, |
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.resume = hv_resume, |
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}; |
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static void (* __initdata old_setup_percpu_clockev)(void); |
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static void __init hv_stimer_setup_percpu_clockev(void) |
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{ |
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/* |
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* Ignore any errors in setting up stimer clockevents |
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* as we can run with the LAPIC timer as a fallback. |
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*/ |
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(void)hv_stimer_alloc(false); |
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/* |
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* Still register the LAPIC timer, because the direct-mode STIMER is |
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* not supported by old versions of Hyper-V. This also allows users |
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* to switch to LAPIC timer via /sys, if they want to. |
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*/ |
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if (old_setup_percpu_clockev) |
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old_setup_percpu_clockev(); |
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} |
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static void __init hv_get_partition_id(void) |
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{ |
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struct hv_get_partition_id *output_page; |
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u64 status; |
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unsigned long flags; |
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local_irq_save(flags); |
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output_page = *this_cpu_ptr(hyperv_pcpu_output_arg); |
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status = hv_do_hypercall(HVCALL_GET_PARTITION_ID, NULL, output_page); |
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if (!hv_result_success(status)) { |
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/* No point in proceeding if this failed */ |
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pr_err("Failed to get partition ID: %lld\n", status); |
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BUG(); |
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} |
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hv_current_partition_id = output_page->partition_id; |
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local_irq_restore(flags); |
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} |
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/* |
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* This function is to be invoked early in the boot sequence after the |
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* hypervisor has been detected. |
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* |
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* 1. Setup the hypercall page. |
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* 2. Register Hyper-V specific clocksource. |
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* 3. Setup Hyper-V specific APIC entry points. |
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*/ |
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void __init hyperv_init(void) |
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{ |
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u64 guest_id, required_msrs; |
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union hv_x64_msr_hypercall_contents hypercall_msr; |
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int cpuhp; |
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if (x86_hyper_type != X86_HYPER_MS_HYPERV) |
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return; |
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/* Absolutely required MSRs */ |
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required_msrs = HV_MSR_HYPERCALL_AVAILABLE | |
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HV_MSR_VP_INDEX_AVAILABLE; |
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if ((ms_hyperv.features & required_msrs) != required_msrs) |
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return; |
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if (hv_common_init()) |
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return; |
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hv_vp_assist_page = kcalloc(num_possible_cpus(), |
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sizeof(*hv_vp_assist_page), GFP_KERNEL); |
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if (!hv_vp_assist_page) { |
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ms_hyperv.hints &= ~HV_X64_ENLIGHTENED_VMCS_RECOMMENDED; |
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goto common_free; |
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} |
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cpuhp = cpuhp_setup_state(CPUHP_AP_ONLINE_DYN, "x86/hyperv_init:online", |
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hv_cpu_init, hv_cpu_die); |
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if (cpuhp < 0) |
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goto free_vp_assist_page; |
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/* |
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* Setup the hypercall page and enable hypercalls. |
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* 1. Register the guest ID |
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* 2. Enable the hypercall and register the hypercall page |
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*/ |
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guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0); |
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wrmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id); |
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hv_hypercall_pg = __vmalloc_node_range(PAGE_SIZE, 1, VMALLOC_START, |
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VMALLOC_END, GFP_KERNEL, PAGE_KERNEL_ROX, |
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VM_FLUSH_RESET_PERMS, NUMA_NO_NODE, |
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__builtin_return_address(0)); |
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if (hv_hypercall_pg == NULL) { |
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wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0); |
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goto remove_cpuhp_state; |
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} |
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rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); |
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hypercall_msr.enable = 1; |
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if (hv_root_partition) { |
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struct page *pg; |
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void *src, *dst; |
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/* |
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* For the root partition, the hypervisor will set up its |
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* hypercall page. The hypervisor guarantees it will not show |
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* up in the root's address space. The root can't change the |
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* location of the hypercall page. |
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* |
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* Order is important here. We must enable the hypercall page |
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* so it is populated with code, then copy the code to an |
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* executable page. |
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*/ |
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wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); |
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pg = vmalloc_to_page(hv_hypercall_pg); |
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dst = kmap(pg); |
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src = memremap(hypercall_msr.guest_physical_address << PAGE_SHIFT, PAGE_SIZE, |
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MEMREMAP_WB); |
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BUG_ON(!(src && dst)); |
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memcpy(dst, src, HV_HYP_PAGE_SIZE); |
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memunmap(src); |
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kunmap(pg); |
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} else { |
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hypercall_msr.guest_physical_address = vmalloc_to_pfn(hv_hypercall_pg); |
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wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); |
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} |
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/* |
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* hyperv_init() is called before LAPIC is initialized: see |
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* apic_intr_mode_init() -> x86_platform.apic_post_init() and |
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* apic_bsp_setup() -> setup_local_APIC(). The direct-mode STIMER |
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* depends on LAPIC, so hv_stimer_alloc() should be called from |
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* x86_init.timers.setup_percpu_clockev. |
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*/ |
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old_setup_percpu_clockev = x86_init.timers.setup_percpu_clockev; |
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x86_init.timers.setup_percpu_clockev = hv_stimer_setup_percpu_clockev; |
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hv_apic_init(); |
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x86_init.pci.arch_init = hv_pci_init; |
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register_syscore_ops(&hv_syscore_ops); |
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hyperv_init_cpuhp = cpuhp; |
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if (cpuid_ebx(HYPERV_CPUID_FEATURES) & HV_ACCESS_PARTITION_ID) |
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hv_get_partition_id(); |
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BUG_ON(hv_root_partition && hv_current_partition_id == ~0ull); |
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#ifdef CONFIG_PCI_MSI |
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/* |
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* If we're running as root, we want to create our own PCI MSI domain. |
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* We can't set this in hv_pci_init because that would be too late. |
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*/ |
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if (hv_root_partition) |
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x86_init.irqs.create_pci_msi_domain = hv_create_pci_msi_domain; |
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#endif |
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/* Query the VMs extended capability once, so that it can be cached. */ |
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hv_query_ext_cap(0); |
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return; |
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remove_cpuhp_state: |
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cpuhp_remove_state(cpuhp); |
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free_vp_assist_page: |
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kfree(hv_vp_assist_page); |
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hv_vp_assist_page = NULL; |
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common_free: |
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hv_common_free(); |
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} |
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/* |
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* This routine is called before kexec/kdump, it does the required cleanup. |
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*/ |
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void hyperv_cleanup(void) |
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{ |
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union hv_x64_msr_hypercall_contents hypercall_msr; |
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unregister_syscore_ops(&hv_syscore_ops); |
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/* Reset our OS id */ |
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wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0); |
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/* |
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* Reset hypercall page reference before reset the page, |
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* let hypercall operations fail safely rather than |
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* panic the kernel for using invalid hypercall page |
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*/ |
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hv_hypercall_pg = NULL; |
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/* Reset the hypercall page */ |
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hypercall_msr.as_uint64 = 0; |
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wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); |
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/* Reset the TSC page */ |
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hypercall_msr.as_uint64 = 0; |
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wrmsrl(HV_X64_MSR_REFERENCE_TSC, hypercall_msr.as_uint64); |
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} |
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void hyperv_report_panic(struct pt_regs *regs, long err, bool in_die) |
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{ |
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static bool panic_reported; |
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u64 guest_id; |
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if (in_die && !panic_on_oops) |
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return; |
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/* |
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* We prefer to report panic on 'die' chain as we have proper |
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* registers to report, but if we miss it (e.g. on BUG()) we need |
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* to report it on 'panic'. |
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*/ |
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if (panic_reported) |
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return; |
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panic_reported = true; |
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rdmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id); |
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wrmsrl(HV_X64_MSR_CRASH_P0, err); |
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wrmsrl(HV_X64_MSR_CRASH_P1, guest_id); |
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wrmsrl(HV_X64_MSR_CRASH_P2, regs->ip); |
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wrmsrl(HV_X64_MSR_CRASH_P3, regs->ax); |
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wrmsrl(HV_X64_MSR_CRASH_P4, regs->sp); |
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/* |
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* Let Hyper-V know there is crash data available |
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*/ |
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wrmsrl(HV_X64_MSR_CRASH_CTL, HV_CRASH_CTL_CRASH_NOTIFY); |
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} |
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EXPORT_SYMBOL_GPL(hyperv_report_panic); |
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bool hv_is_hyperv_initialized(void) |
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{ |
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union hv_x64_msr_hypercall_contents hypercall_msr; |
|
|
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/* |
|
* Ensure that we're really on Hyper-V, and not a KVM or Xen |
|
* emulation of Hyper-V |
|
*/ |
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if (x86_hyper_type != X86_HYPER_MS_HYPERV) |
|
return false; |
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|
|
/* |
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* Verify that earlier initialization succeeded by checking |
|
* that the hypercall page is setup |
|
*/ |
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hypercall_msr.as_uint64 = 0; |
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rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64); |
|
|
|
return hypercall_msr.enable; |
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} |
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EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized); |
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|
|
enum hv_isolation_type hv_get_isolation_type(void) |
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{ |
|
if (!(ms_hyperv.priv_high & HV_ISOLATION)) |
|
return HV_ISOLATION_TYPE_NONE; |
|
return FIELD_GET(HV_ISOLATION_TYPE, ms_hyperv.isolation_config_b); |
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} |
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EXPORT_SYMBOL_GPL(hv_get_isolation_type); |
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|
|
bool hv_is_isolation_supported(void) |
|
{ |
|
return hv_get_isolation_type() != HV_ISOLATION_TYPE_NONE; |
|
}
|
|
|