![Wanpeng Li](/assets/img/avatar_default.png)
If host CPUs are dedicated to a VM, we can avoid VM exits on HLT. This patch adds the per-VM capability to disable them. Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Jan H. Schönherr <jschoenh@amazon.de> Signed-off-by: Wanpeng Li <wanpengli@tencent.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
934 lines
24 KiB
C
934 lines
24 KiB
C
/*
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* Kernel-based Virtual Machine driver for Linux
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* cpuid support routines
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*
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* derived from arch/x86/kvm/x86.c
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*
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* Copyright 2011 Red Hat, Inc. and/or its affiliates.
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* Copyright IBM Corporation, 2008
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*
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* This work is licensed under the terms of the GNU GPL, version 2. See
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* the COPYING file in the top-level directory.
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*
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*/
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#include <linux/kvm_host.h>
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#include <linux/export.h>
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#include <linux/vmalloc.h>
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#include <linux/uaccess.h>
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#include <linux/sched/stat.h>
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#include <asm/processor.h>
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#include <asm/user.h>
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#include <asm/fpu/xstate.h>
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#include "cpuid.h"
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#include "lapic.h"
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#include "mmu.h"
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#include "trace.h"
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#include "pmu.h"
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static u32 xstate_required_size(u64 xstate_bv, bool compacted)
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{
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int feature_bit = 0;
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u32 ret = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
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xstate_bv &= XFEATURE_MASK_EXTEND;
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while (xstate_bv) {
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if (xstate_bv & 0x1) {
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u32 eax, ebx, ecx, edx, offset;
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cpuid_count(0xD, feature_bit, &eax, &ebx, &ecx, &edx);
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offset = compacted ? ret : ebx;
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ret = max(ret, offset + eax);
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}
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xstate_bv >>= 1;
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feature_bit++;
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}
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return ret;
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}
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bool kvm_mpx_supported(void)
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{
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return ((host_xcr0 & (XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR))
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&& kvm_x86_ops->mpx_supported());
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}
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EXPORT_SYMBOL_GPL(kvm_mpx_supported);
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u64 kvm_supported_xcr0(void)
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{
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u64 xcr0 = KVM_SUPPORTED_XCR0 & host_xcr0;
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if (!kvm_mpx_supported())
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xcr0 &= ~(XFEATURE_MASK_BNDREGS | XFEATURE_MASK_BNDCSR);
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return xcr0;
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}
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#define F(x) bit(X86_FEATURE_##x)
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/* For scattered features from cpufeatures.h; we currently expose none */
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#define KF(x) bit(KVM_CPUID_BIT_##x)
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int kvm_update_cpuid(struct kvm_vcpu *vcpu)
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{
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struct kvm_cpuid_entry2 *best;
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struct kvm_lapic *apic = vcpu->arch.apic;
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best = kvm_find_cpuid_entry(vcpu, 1, 0);
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if (!best)
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return 0;
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/* Update OSXSAVE bit */
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if (boot_cpu_has(X86_FEATURE_XSAVE) && best->function == 0x1) {
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best->ecx &= ~F(OSXSAVE);
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if (kvm_read_cr4_bits(vcpu, X86_CR4_OSXSAVE))
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best->ecx |= F(OSXSAVE);
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}
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best->edx &= ~F(APIC);
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if (vcpu->arch.apic_base & MSR_IA32_APICBASE_ENABLE)
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best->edx |= F(APIC);
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if (apic) {
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if (best->ecx & F(TSC_DEADLINE_TIMER))
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apic->lapic_timer.timer_mode_mask = 3 << 17;
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else
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apic->lapic_timer.timer_mode_mask = 1 << 17;
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}
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best = kvm_find_cpuid_entry(vcpu, 7, 0);
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if (best) {
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/* Update OSPKE bit */
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if (boot_cpu_has(X86_FEATURE_PKU) && best->function == 0x7) {
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best->ecx &= ~F(OSPKE);
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if (kvm_read_cr4_bits(vcpu, X86_CR4_PKE))
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best->ecx |= F(OSPKE);
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}
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}
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best = kvm_find_cpuid_entry(vcpu, 0xD, 0);
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if (!best) {
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vcpu->arch.guest_supported_xcr0 = 0;
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vcpu->arch.guest_xstate_size = XSAVE_HDR_SIZE + XSAVE_HDR_OFFSET;
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} else {
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vcpu->arch.guest_supported_xcr0 =
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(best->eax | ((u64)best->edx << 32)) &
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kvm_supported_xcr0();
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vcpu->arch.guest_xstate_size = best->ebx =
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xstate_required_size(vcpu->arch.xcr0, false);
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}
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best = kvm_find_cpuid_entry(vcpu, 0xD, 1);
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if (best && (best->eax & (F(XSAVES) | F(XSAVEC))))
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best->ebx = xstate_required_size(vcpu->arch.xcr0, true);
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/*
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* The existing code assumes virtual address is 48-bit or 57-bit in the
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* canonical address checks; exit if it is ever changed.
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*/
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best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
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if (best) {
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int vaddr_bits = (best->eax & 0xff00) >> 8;
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if (vaddr_bits != 48 && vaddr_bits != 57 && vaddr_bits != 0)
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return -EINVAL;
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}
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best = kvm_find_cpuid_entry(vcpu, KVM_CPUID_FEATURES, 0);
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if (kvm_hlt_in_guest(vcpu->kvm) && best &&
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(best->eax & (1 << KVM_FEATURE_PV_UNHALT)))
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best->eax &= ~(1 << KVM_FEATURE_PV_UNHALT);
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/* Update physical-address width */
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vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
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kvm_mmu_reset_context(vcpu);
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kvm_pmu_refresh(vcpu);
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return 0;
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}
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static int is_efer_nx(void)
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{
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unsigned long long efer = 0;
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rdmsrl_safe(MSR_EFER, &efer);
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return efer & EFER_NX;
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}
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static void cpuid_fix_nx_cap(struct kvm_vcpu *vcpu)
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{
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int i;
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struct kvm_cpuid_entry2 *e, *entry;
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entry = NULL;
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for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
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e = &vcpu->arch.cpuid_entries[i];
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if (e->function == 0x80000001) {
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entry = e;
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break;
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}
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}
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if (entry && (entry->edx & F(NX)) && !is_efer_nx()) {
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entry->edx &= ~F(NX);
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printk(KERN_INFO "kvm: guest NX capability removed\n");
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}
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}
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int cpuid_query_maxphyaddr(struct kvm_vcpu *vcpu)
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{
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struct kvm_cpuid_entry2 *best;
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best = kvm_find_cpuid_entry(vcpu, 0x80000000, 0);
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if (!best || best->eax < 0x80000008)
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goto not_found;
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best = kvm_find_cpuid_entry(vcpu, 0x80000008, 0);
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if (best)
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return best->eax & 0xff;
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not_found:
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return 36;
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}
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EXPORT_SYMBOL_GPL(cpuid_query_maxphyaddr);
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/* when an old userspace process fills a new kernel module */
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int kvm_vcpu_ioctl_set_cpuid(struct kvm_vcpu *vcpu,
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struct kvm_cpuid *cpuid,
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struct kvm_cpuid_entry __user *entries)
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{
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int r, i;
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struct kvm_cpuid_entry *cpuid_entries = NULL;
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r = -E2BIG;
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if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
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goto out;
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r = -ENOMEM;
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if (cpuid->nent) {
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cpuid_entries = vmalloc(sizeof(struct kvm_cpuid_entry) *
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cpuid->nent);
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if (!cpuid_entries)
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goto out;
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r = -EFAULT;
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if (copy_from_user(cpuid_entries, entries,
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cpuid->nent * sizeof(struct kvm_cpuid_entry)))
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goto out;
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}
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for (i = 0; i < cpuid->nent; i++) {
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vcpu->arch.cpuid_entries[i].function = cpuid_entries[i].function;
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vcpu->arch.cpuid_entries[i].eax = cpuid_entries[i].eax;
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vcpu->arch.cpuid_entries[i].ebx = cpuid_entries[i].ebx;
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vcpu->arch.cpuid_entries[i].ecx = cpuid_entries[i].ecx;
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vcpu->arch.cpuid_entries[i].edx = cpuid_entries[i].edx;
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vcpu->arch.cpuid_entries[i].index = 0;
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vcpu->arch.cpuid_entries[i].flags = 0;
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vcpu->arch.cpuid_entries[i].padding[0] = 0;
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vcpu->arch.cpuid_entries[i].padding[1] = 0;
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vcpu->arch.cpuid_entries[i].padding[2] = 0;
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}
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vcpu->arch.cpuid_nent = cpuid->nent;
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cpuid_fix_nx_cap(vcpu);
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kvm_apic_set_version(vcpu);
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kvm_x86_ops->cpuid_update(vcpu);
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r = kvm_update_cpuid(vcpu);
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out:
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vfree(cpuid_entries);
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return r;
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}
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int kvm_vcpu_ioctl_set_cpuid2(struct kvm_vcpu *vcpu,
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struct kvm_cpuid2 *cpuid,
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struct kvm_cpuid_entry2 __user *entries)
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{
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int r;
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r = -E2BIG;
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if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
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goto out;
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r = -EFAULT;
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if (copy_from_user(&vcpu->arch.cpuid_entries, entries,
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cpuid->nent * sizeof(struct kvm_cpuid_entry2)))
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goto out;
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vcpu->arch.cpuid_nent = cpuid->nent;
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kvm_apic_set_version(vcpu);
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kvm_x86_ops->cpuid_update(vcpu);
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r = kvm_update_cpuid(vcpu);
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out:
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return r;
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}
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int kvm_vcpu_ioctl_get_cpuid2(struct kvm_vcpu *vcpu,
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struct kvm_cpuid2 *cpuid,
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struct kvm_cpuid_entry2 __user *entries)
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{
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int r;
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r = -E2BIG;
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if (cpuid->nent < vcpu->arch.cpuid_nent)
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goto out;
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r = -EFAULT;
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if (copy_to_user(entries, &vcpu->arch.cpuid_entries,
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vcpu->arch.cpuid_nent * sizeof(struct kvm_cpuid_entry2)))
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goto out;
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return 0;
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out:
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cpuid->nent = vcpu->arch.cpuid_nent;
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return r;
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}
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static void cpuid_mask(u32 *word, int wordnum)
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{
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*word &= boot_cpu_data.x86_capability[wordnum];
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}
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static void do_cpuid_1_ent(struct kvm_cpuid_entry2 *entry, u32 function,
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u32 index)
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{
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entry->function = function;
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entry->index = index;
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cpuid_count(entry->function, entry->index,
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&entry->eax, &entry->ebx, &entry->ecx, &entry->edx);
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entry->flags = 0;
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}
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static int __do_cpuid_ent_emulated(struct kvm_cpuid_entry2 *entry,
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u32 func, u32 index, int *nent, int maxnent)
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{
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switch (func) {
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case 0:
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entry->eax = 7;
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++*nent;
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break;
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case 1:
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entry->ecx = F(MOVBE);
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++*nent;
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break;
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case 7:
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entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
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if (index == 0)
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entry->ecx = F(RDPID);
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++*nent;
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default:
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break;
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}
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entry->function = func;
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entry->index = index;
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return 0;
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}
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static inline int __do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function,
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u32 index, int *nent, int maxnent)
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{
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int r;
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unsigned f_nx = is_efer_nx() ? F(NX) : 0;
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#ifdef CONFIG_X86_64
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unsigned f_gbpages = (kvm_x86_ops->get_lpage_level() == PT_PDPE_LEVEL)
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? F(GBPAGES) : 0;
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unsigned f_lm = F(LM);
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#else
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unsigned f_gbpages = 0;
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unsigned f_lm = 0;
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#endif
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unsigned f_rdtscp = kvm_x86_ops->rdtscp_supported() ? F(RDTSCP) : 0;
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unsigned f_invpcid = kvm_x86_ops->invpcid_supported() ? F(INVPCID) : 0;
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unsigned f_mpx = kvm_mpx_supported() ? F(MPX) : 0;
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unsigned f_xsaves = kvm_x86_ops->xsaves_supported() ? F(XSAVES) : 0;
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unsigned f_umip = kvm_x86_ops->umip_emulated() ? F(UMIP) : 0;
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/* cpuid 1.edx */
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const u32 kvm_cpuid_1_edx_x86_features =
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F(FPU) | F(VME) | F(DE) | F(PSE) |
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F(TSC) | F(MSR) | F(PAE) | F(MCE) |
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F(CX8) | F(APIC) | 0 /* Reserved */ | F(SEP) |
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F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
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F(PAT) | F(PSE36) | 0 /* PSN */ | F(CLFLUSH) |
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0 /* Reserved, DS, ACPI */ | F(MMX) |
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F(FXSR) | F(XMM) | F(XMM2) | F(SELFSNOOP) |
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0 /* HTT, TM, Reserved, PBE */;
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/* cpuid 0x80000001.edx */
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const u32 kvm_cpuid_8000_0001_edx_x86_features =
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F(FPU) | F(VME) | F(DE) | F(PSE) |
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F(TSC) | F(MSR) | F(PAE) | F(MCE) |
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F(CX8) | F(APIC) | 0 /* Reserved */ | F(SYSCALL) |
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F(MTRR) | F(PGE) | F(MCA) | F(CMOV) |
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F(PAT) | F(PSE36) | 0 /* Reserved */ |
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f_nx | 0 /* Reserved */ | F(MMXEXT) | F(MMX) |
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F(FXSR) | F(FXSR_OPT) | f_gbpages | f_rdtscp |
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0 /* Reserved */ | f_lm | F(3DNOWEXT) | F(3DNOW);
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/* cpuid 1.ecx */
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const u32 kvm_cpuid_1_ecx_x86_features =
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/* NOTE: MONITOR (and MWAIT) are emulated as NOP,
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* but *not* advertised to guests via CPUID ! */
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F(XMM3) | F(PCLMULQDQ) | 0 /* DTES64, MONITOR */ |
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0 /* DS-CPL, VMX, SMX, EST */ |
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0 /* TM2 */ | F(SSSE3) | 0 /* CNXT-ID */ | 0 /* Reserved */ |
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F(FMA) | F(CX16) | 0 /* xTPR Update, PDCM */ |
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F(PCID) | 0 /* Reserved, DCA */ | F(XMM4_1) |
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F(XMM4_2) | F(X2APIC) | F(MOVBE) | F(POPCNT) |
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0 /* Reserved*/ | F(AES) | F(XSAVE) | 0 /* OSXSAVE */ | F(AVX) |
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F(F16C) | F(RDRAND);
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/* cpuid 0x80000001.ecx */
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const u32 kvm_cpuid_8000_0001_ecx_x86_features =
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F(LAHF_LM) | F(CMP_LEGACY) | 0 /*SVM*/ | 0 /* ExtApicSpace */ |
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F(CR8_LEGACY) | F(ABM) | F(SSE4A) | F(MISALIGNSSE) |
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F(3DNOWPREFETCH) | F(OSVW) | 0 /* IBS */ | F(XOP) |
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0 /* SKINIT, WDT, LWP */ | F(FMA4) | F(TBM) |
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F(TOPOEXT) | F(PERFCTR_CORE);
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|
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/* cpuid 0x80000008.ebx */
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const u32 kvm_cpuid_8000_0008_ebx_x86_features =
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F(IBPB) | F(IBRS);
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|
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/* cpuid 0xC0000001.edx */
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const u32 kvm_cpuid_C000_0001_edx_x86_features =
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F(XSTORE) | F(XSTORE_EN) | F(XCRYPT) | F(XCRYPT_EN) |
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F(ACE2) | F(ACE2_EN) | F(PHE) | F(PHE_EN) |
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F(PMM) | F(PMM_EN);
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|
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/* cpuid 7.0.ebx */
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const u32 kvm_cpuid_7_0_ebx_x86_features =
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F(FSGSBASE) | F(BMI1) | F(HLE) | F(AVX2) | F(SMEP) |
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F(BMI2) | F(ERMS) | f_invpcid | F(RTM) | f_mpx | F(RDSEED) |
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F(ADX) | F(SMAP) | F(AVX512IFMA) | F(AVX512F) | F(AVX512PF) |
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F(AVX512ER) | F(AVX512CD) | F(CLFLUSHOPT) | F(CLWB) | F(AVX512DQ) |
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F(SHA_NI) | F(AVX512BW) | F(AVX512VL);
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|
|
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/* cpuid 0xD.1.eax */
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const u32 kvm_cpuid_D_1_eax_x86_features =
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F(XSAVEOPT) | F(XSAVEC) | F(XGETBV1) | f_xsaves;
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/* cpuid 7.0.ecx*/
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const u32 kvm_cpuid_7_0_ecx_x86_features =
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F(AVX512VBMI) | F(LA57) | F(PKU) | 0 /*OSPKE*/ |
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F(AVX512_VPOPCNTDQ) | F(UMIP) | F(AVX512_VBMI2) | F(GFNI) |
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F(VAES) | F(VPCLMULQDQ) | F(AVX512_VNNI) | F(AVX512_BITALG);
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|
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/* cpuid 7.0.edx*/
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const u32 kvm_cpuid_7_0_edx_x86_features =
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F(AVX512_4VNNIW) | F(AVX512_4FMAPS) | F(SPEC_CTRL) |
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F(ARCH_CAPABILITIES);
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|
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/* all calls to cpuid_count() should be made on the same cpu */
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get_cpu();
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|
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r = -E2BIG;
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|
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if (*nent >= maxnent)
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goto out;
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do_cpuid_1_ent(entry, function, index);
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++*nent;
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|
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switch (function) {
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|
case 0:
|
|
entry->eax = min(entry->eax, (u32)0xd);
|
|
break;
|
|
case 1:
|
|
entry->edx &= kvm_cpuid_1_edx_x86_features;
|
|
cpuid_mask(&entry->edx, CPUID_1_EDX);
|
|
entry->ecx &= kvm_cpuid_1_ecx_x86_features;
|
|
cpuid_mask(&entry->ecx, CPUID_1_ECX);
|
|
/* we support x2apic emulation even if host does not support
|
|
* it since we emulate x2apic in software */
|
|
entry->ecx |= F(X2APIC);
|
|
break;
|
|
/* function 2 entries are STATEFUL. That is, repeated cpuid commands
|
|
* may return different values. This forces us to get_cpu() before
|
|
* issuing the first command, and also to emulate this annoying behavior
|
|
* in kvm_emulate_cpuid() using KVM_CPUID_FLAG_STATE_READ_NEXT */
|
|
case 2: {
|
|
int t, times = entry->eax & 0xff;
|
|
|
|
entry->flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
|
|
entry->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
|
|
for (t = 1; t < times; ++t) {
|
|
if (*nent >= maxnent)
|
|
goto out;
|
|
|
|
do_cpuid_1_ent(&entry[t], function, 0);
|
|
entry[t].flags |= KVM_CPUID_FLAG_STATEFUL_FUNC;
|
|
++*nent;
|
|
}
|
|
break;
|
|
}
|
|
/* function 4 has additional index. */
|
|
case 4: {
|
|
int i, cache_type;
|
|
|
|
entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
|
|
/* read more entries until cache_type is zero */
|
|
for (i = 1; ; ++i) {
|
|
if (*nent >= maxnent)
|
|
goto out;
|
|
|
|
cache_type = entry[i - 1].eax & 0x1f;
|
|
if (!cache_type)
|
|
break;
|
|
do_cpuid_1_ent(&entry[i], function, i);
|
|
entry[i].flags |=
|
|
KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
|
|
++*nent;
|
|
}
|
|
break;
|
|
}
|
|
case 6: /* Thermal management */
|
|
entry->eax = 0x4; /* allow ARAT */
|
|
entry->ebx = 0;
|
|
entry->ecx = 0;
|
|
entry->edx = 0;
|
|
break;
|
|
case 7: {
|
|
entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
|
|
/* Mask ebx against host capability word 9 */
|
|
if (index == 0) {
|
|
entry->ebx &= kvm_cpuid_7_0_ebx_x86_features;
|
|
cpuid_mask(&entry->ebx, CPUID_7_0_EBX);
|
|
// TSC_ADJUST is emulated
|
|
entry->ebx |= F(TSC_ADJUST);
|
|
entry->ecx &= kvm_cpuid_7_0_ecx_x86_features;
|
|
cpuid_mask(&entry->ecx, CPUID_7_ECX);
|
|
entry->ecx |= f_umip;
|
|
/* PKU is not yet implemented for shadow paging. */
|
|
if (!tdp_enabled || !boot_cpu_has(X86_FEATURE_OSPKE))
|
|
entry->ecx &= ~F(PKU);
|
|
entry->edx &= kvm_cpuid_7_0_edx_x86_features;
|
|
cpuid_mask(&entry->edx, CPUID_7_EDX);
|
|
} else {
|
|
entry->ebx = 0;
|
|
entry->ecx = 0;
|
|
entry->edx = 0;
|
|
}
|
|
entry->eax = 0;
|
|
break;
|
|
}
|
|
case 9:
|
|
break;
|
|
case 0xa: { /* Architectural Performance Monitoring */
|
|
struct x86_pmu_capability cap;
|
|
union cpuid10_eax eax;
|
|
union cpuid10_edx edx;
|
|
|
|
perf_get_x86_pmu_capability(&cap);
|
|
|
|
/*
|
|
* Only support guest architectural pmu on a host
|
|
* with architectural pmu.
|
|
*/
|
|
if (!cap.version)
|
|
memset(&cap, 0, sizeof(cap));
|
|
|
|
eax.split.version_id = min(cap.version, 2);
|
|
eax.split.num_counters = cap.num_counters_gp;
|
|
eax.split.bit_width = cap.bit_width_gp;
|
|
eax.split.mask_length = cap.events_mask_len;
|
|
|
|
edx.split.num_counters_fixed = cap.num_counters_fixed;
|
|
edx.split.bit_width_fixed = cap.bit_width_fixed;
|
|
edx.split.reserved = 0;
|
|
|
|
entry->eax = eax.full;
|
|
entry->ebx = cap.events_mask;
|
|
entry->ecx = 0;
|
|
entry->edx = edx.full;
|
|
break;
|
|
}
|
|
/* function 0xb has additional index. */
|
|
case 0xb: {
|
|
int i, level_type;
|
|
|
|
entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
|
|
/* read more entries until level_type is zero */
|
|
for (i = 1; ; ++i) {
|
|
if (*nent >= maxnent)
|
|
goto out;
|
|
|
|
level_type = entry[i - 1].ecx & 0xff00;
|
|
if (!level_type)
|
|
break;
|
|
do_cpuid_1_ent(&entry[i], function, i);
|
|
entry[i].flags |=
|
|
KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
|
|
++*nent;
|
|
}
|
|
break;
|
|
}
|
|
case 0xd: {
|
|
int idx, i;
|
|
u64 supported = kvm_supported_xcr0();
|
|
|
|
entry->eax &= supported;
|
|
entry->ebx = xstate_required_size(supported, false);
|
|
entry->ecx = entry->ebx;
|
|
entry->edx &= supported >> 32;
|
|
entry->flags |= KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
|
|
if (!supported)
|
|
break;
|
|
|
|
for (idx = 1, i = 1; idx < 64; ++idx) {
|
|
u64 mask = ((u64)1 << idx);
|
|
if (*nent >= maxnent)
|
|
goto out;
|
|
|
|
do_cpuid_1_ent(&entry[i], function, idx);
|
|
if (idx == 1) {
|
|
entry[i].eax &= kvm_cpuid_D_1_eax_x86_features;
|
|
cpuid_mask(&entry[i].eax, CPUID_D_1_EAX);
|
|
entry[i].ebx = 0;
|
|
if (entry[i].eax & (F(XSAVES)|F(XSAVEC)))
|
|
entry[i].ebx =
|
|
xstate_required_size(supported,
|
|
true);
|
|
} else {
|
|
if (entry[i].eax == 0 || !(supported & mask))
|
|
continue;
|
|
if (WARN_ON_ONCE(entry[i].ecx & 1))
|
|
continue;
|
|
}
|
|
entry[i].ecx = 0;
|
|
entry[i].edx = 0;
|
|
entry[i].flags |=
|
|
KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
|
|
++*nent;
|
|
++i;
|
|
}
|
|
break;
|
|
}
|
|
case KVM_CPUID_SIGNATURE: {
|
|
static const char signature[12] = "KVMKVMKVM\0\0";
|
|
const u32 *sigptr = (const u32 *)signature;
|
|
entry->eax = KVM_CPUID_FEATURES;
|
|
entry->ebx = sigptr[0];
|
|
entry->ecx = sigptr[1];
|
|
entry->edx = sigptr[2];
|
|
break;
|
|
}
|
|
case KVM_CPUID_FEATURES:
|
|
entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) |
|
|
(1 << KVM_FEATURE_NOP_IO_DELAY) |
|
|
(1 << KVM_FEATURE_CLOCKSOURCE2) |
|
|
(1 << KVM_FEATURE_ASYNC_PF) |
|
|
(1 << KVM_FEATURE_PV_EOI) |
|
|
(1 << KVM_FEATURE_CLOCKSOURCE_STABLE_BIT) |
|
|
(1 << KVM_FEATURE_PV_UNHALT) |
|
|
(1 << KVM_FEATURE_PV_TLB_FLUSH) |
|
|
(1 << KVM_FEATURE_ASYNC_PF_VMEXIT);
|
|
|
|
if (sched_info_on())
|
|
entry->eax |= (1 << KVM_FEATURE_STEAL_TIME);
|
|
|
|
entry->ebx = 0;
|
|
entry->ecx = 0;
|
|
entry->edx = 0;
|
|
break;
|
|
case 0x80000000:
|
|
entry->eax = min(entry->eax, 0x8000001f);
|
|
break;
|
|
case 0x80000001:
|
|
entry->edx &= kvm_cpuid_8000_0001_edx_x86_features;
|
|
cpuid_mask(&entry->edx, CPUID_8000_0001_EDX);
|
|
entry->ecx &= kvm_cpuid_8000_0001_ecx_x86_features;
|
|
cpuid_mask(&entry->ecx, CPUID_8000_0001_ECX);
|
|
break;
|
|
case 0x80000007: /* Advanced power management */
|
|
/* invariant TSC is CPUID.80000007H:EDX[8] */
|
|
entry->edx &= (1 << 8);
|
|
/* mask against host */
|
|
entry->edx &= boot_cpu_data.x86_power;
|
|
entry->eax = entry->ebx = entry->ecx = 0;
|
|
break;
|
|
case 0x80000008: {
|
|
unsigned g_phys_as = (entry->eax >> 16) & 0xff;
|
|
unsigned virt_as = max((entry->eax >> 8) & 0xff, 48U);
|
|
unsigned phys_as = entry->eax & 0xff;
|
|
|
|
if (!g_phys_as)
|
|
g_phys_as = phys_as;
|
|
entry->eax = g_phys_as | (virt_as << 8);
|
|
entry->edx = 0;
|
|
/* IBRS and IBPB aren't necessarily present in hardware cpuid */
|
|
if (boot_cpu_has(X86_FEATURE_IBPB))
|
|
entry->ebx |= F(IBPB);
|
|
if (boot_cpu_has(X86_FEATURE_IBRS))
|
|
entry->ebx |= F(IBRS);
|
|
entry->ebx &= kvm_cpuid_8000_0008_ebx_x86_features;
|
|
cpuid_mask(&entry->ebx, CPUID_8000_0008_EBX);
|
|
break;
|
|
}
|
|
case 0x80000019:
|
|
entry->ecx = entry->edx = 0;
|
|
break;
|
|
case 0x8000001a:
|
|
break;
|
|
case 0x8000001d:
|
|
break;
|
|
/*Add support for Centaur's CPUID instruction*/
|
|
case 0xC0000000:
|
|
/*Just support up to 0xC0000004 now*/
|
|
entry->eax = min(entry->eax, 0xC0000004);
|
|
break;
|
|
case 0xC0000001:
|
|
entry->edx &= kvm_cpuid_C000_0001_edx_x86_features;
|
|
cpuid_mask(&entry->edx, CPUID_C000_0001_EDX);
|
|
break;
|
|
case 3: /* Processor serial number */
|
|
case 5: /* MONITOR/MWAIT */
|
|
case 0xC0000002:
|
|
case 0xC0000003:
|
|
case 0xC0000004:
|
|
default:
|
|
entry->eax = entry->ebx = entry->ecx = entry->edx = 0;
|
|
break;
|
|
}
|
|
|
|
kvm_x86_ops->set_supported_cpuid(function, entry);
|
|
|
|
r = 0;
|
|
|
|
out:
|
|
put_cpu();
|
|
|
|
return r;
|
|
}
|
|
|
|
static int do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 func,
|
|
u32 idx, int *nent, int maxnent, unsigned int type)
|
|
{
|
|
if (type == KVM_GET_EMULATED_CPUID)
|
|
return __do_cpuid_ent_emulated(entry, func, idx, nent, maxnent);
|
|
|
|
return __do_cpuid_ent(entry, func, idx, nent, maxnent);
|
|
}
|
|
|
|
#undef F
|
|
|
|
struct kvm_cpuid_param {
|
|
u32 func;
|
|
u32 idx;
|
|
bool has_leaf_count;
|
|
bool (*qualifier)(const struct kvm_cpuid_param *param);
|
|
};
|
|
|
|
static bool is_centaur_cpu(const struct kvm_cpuid_param *param)
|
|
{
|
|
return boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR;
|
|
}
|
|
|
|
static bool sanity_check_entries(struct kvm_cpuid_entry2 __user *entries,
|
|
__u32 num_entries, unsigned int ioctl_type)
|
|
{
|
|
int i;
|
|
__u32 pad[3];
|
|
|
|
if (ioctl_type != KVM_GET_EMULATED_CPUID)
|
|
return false;
|
|
|
|
/*
|
|
* We want to make sure that ->padding is being passed clean from
|
|
* userspace in case we want to use it for something in the future.
|
|
*
|
|
* Sadly, this wasn't enforced for KVM_GET_SUPPORTED_CPUID and so we
|
|
* have to give ourselves satisfied only with the emulated side. /me
|
|
* sheds a tear.
|
|
*/
|
|
for (i = 0; i < num_entries; i++) {
|
|
if (copy_from_user(pad, entries[i].padding, sizeof(pad)))
|
|
return true;
|
|
|
|
if (pad[0] || pad[1] || pad[2])
|
|
return true;
|
|
}
|
|
return false;
|
|
}
|
|
|
|
int kvm_dev_ioctl_get_cpuid(struct kvm_cpuid2 *cpuid,
|
|
struct kvm_cpuid_entry2 __user *entries,
|
|
unsigned int type)
|
|
{
|
|
struct kvm_cpuid_entry2 *cpuid_entries;
|
|
int limit, nent = 0, r = -E2BIG, i;
|
|
u32 func;
|
|
static const struct kvm_cpuid_param param[] = {
|
|
{ .func = 0, .has_leaf_count = true },
|
|
{ .func = 0x80000000, .has_leaf_count = true },
|
|
{ .func = 0xC0000000, .qualifier = is_centaur_cpu, .has_leaf_count = true },
|
|
{ .func = KVM_CPUID_SIGNATURE },
|
|
{ .func = KVM_CPUID_FEATURES },
|
|
};
|
|
|
|
if (cpuid->nent < 1)
|
|
goto out;
|
|
if (cpuid->nent > KVM_MAX_CPUID_ENTRIES)
|
|
cpuid->nent = KVM_MAX_CPUID_ENTRIES;
|
|
|
|
if (sanity_check_entries(entries, cpuid->nent, type))
|
|
return -EINVAL;
|
|
|
|
r = -ENOMEM;
|
|
cpuid_entries = vzalloc(sizeof(struct kvm_cpuid_entry2) * cpuid->nent);
|
|
if (!cpuid_entries)
|
|
goto out;
|
|
|
|
r = 0;
|
|
for (i = 0; i < ARRAY_SIZE(param); i++) {
|
|
const struct kvm_cpuid_param *ent = ¶m[i];
|
|
|
|
if (ent->qualifier && !ent->qualifier(ent))
|
|
continue;
|
|
|
|
r = do_cpuid_ent(&cpuid_entries[nent], ent->func, ent->idx,
|
|
&nent, cpuid->nent, type);
|
|
|
|
if (r)
|
|
goto out_free;
|
|
|
|
if (!ent->has_leaf_count)
|
|
continue;
|
|
|
|
limit = cpuid_entries[nent - 1].eax;
|
|
for (func = ent->func + 1; func <= limit && nent < cpuid->nent && r == 0; ++func)
|
|
r = do_cpuid_ent(&cpuid_entries[nent], func, ent->idx,
|
|
&nent, cpuid->nent, type);
|
|
|
|
if (r)
|
|
goto out_free;
|
|
}
|
|
|
|
r = -EFAULT;
|
|
if (copy_to_user(entries, cpuid_entries,
|
|
nent * sizeof(struct kvm_cpuid_entry2)))
|
|
goto out_free;
|
|
cpuid->nent = nent;
|
|
r = 0;
|
|
|
|
out_free:
|
|
vfree(cpuid_entries);
|
|
out:
|
|
return r;
|
|
}
|
|
|
|
static int move_to_next_stateful_cpuid_entry(struct kvm_vcpu *vcpu, int i)
|
|
{
|
|
struct kvm_cpuid_entry2 *e = &vcpu->arch.cpuid_entries[i];
|
|
struct kvm_cpuid_entry2 *ej;
|
|
int j = i;
|
|
int nent = vcpu->arch.cpuid_nent;
|
|
|
|
e->flags &= ~KVM_CPUID_FLAG_STATE_READ_NEXT;
|
|
/* when no next entry is found, the current entry[i] is reselected */
|
|
do {
|
|
j = (j + 1) % nent;
|
|
ej = &vcpu->arch.cpuid_entries[j];
|
|
} while (ej->function != e->function);
|
|
|
|
ej->flags |= KVM_CPUID_FLAG_STATE_READ_NEXT;
|
|
|
|
return j;
|
|
}
|
|
|
|
/* find an entry with matching function, matching index (if needed), and that
|
|
* should be read next (if it's stateful) */
|
|
static int is_matching_cpuid_entry(struct kvm_cpuid_entry2 *e,
|
|
u32 function, u32 index)
|
|
{
|
|
if (e->function != function)
|
|
return 0;
|
|
if ((e->flags & KVM_CPUID_FLAG_SIGNIFCANT_INDEX) && e->index != index)
|
|
return 0;
|
|
if ((e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC) &&
|
|
!(e->flags & KVM_CPUID_FLAG_STATE_READ_NEXT))
|
|
return 0;
|
|
return 1;
|
|
}
|
|
|
|
struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
|
|
u32 function, u32 index)
|
|
{
|
|
int i;
|
|
struct kvm_cpuid_entry2 *best = NULL;
|
|
|
|
for (i = 0; i < vcpu->arch.cpuid_nent; ++i) {
|
|
struct kvm_cpuid_entry2 *e;
|
|
|
|
e = &vcpu->arch.cpuid_entries[i];
|
|
if (is_matching_cpuid_entry(e, function, index)) {
|
|
if (e->flags & KVM_CPUID_FLAG_STATEFUL_FUNC)
|
|
move_to_next_stateful_cpuid_entry(vcpu, i);
|
|
best = e;
|
|
break;
|
|
}
|
|
}
|
|
return best;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kvm_find_cpuid_entry);
|
|
|
|
/*
|
|
* If no match is found, check whether we exceed the vCPU's limit
|
|
* and return the content of the highest valid _standard_ leaf instead.
|
|
* This is to satisfy the CPUID specification.
|
|
*/
|
|
static struct kvm_cpuid_entry2* check_cpuid_limit(struct kvm_vcpu *vcpu,
|
|
u32 function, u32 index)
|
|
{
|
|
struct kvm_cpuid_entry2 *maxlevel;
|
|
|
|
maxlevel = kvm_find_cpuid_entry(vcpu, function & 0x80000000, 0);
|
|
if (!maxlevel || maxlevel->eax >= function)
|
|
return NULL;
|
|
if (function & 0x80000000) {
|
|
maxlevel = kvm_find_cpuid_entry(vcpu, 0, 0);
|
|
if (!maxlevel)
|
|
return NULL;
|
|
}
|
|
return kvm_find_cpuid_entry(vcpu, maxlevel->eax, index);
|
|
}
|
|
|
|
bool kvm_cpuid(struct kvm_vcpu *vcpu, u32 *eax, u32 *ebx,
|
|
u32 *ecx, u32 *edx, bool check_limit)
|
|
{
|
|
u32 function = *eax, index = *ecx;
|
|
struct kvm_cpuid_entry2 *best;
|
|
bool entry_found = true;
|
|
|
|
best = kvm_find_cpuid_entry(vcpu, function, index);
|
|
|
|
if (!best) {
|
|
entry_found = false;
|
|
if (!check_limit)
|
|
goto out;
|
|
|
|
best = check_cpuid_limit(vcpu, function, index);
|
|
}
|
|
|
|
out:
|
|
if (best) {
|
|
*eax = best->eax;
|
|
*ebx = best->ebx;
|
|
*ecx = best->ecx;
|
|
*edx = best->edx;
|
|
} else
|
|
*eax = *ebx = *ecx = *edx = 0;
|
|
trace_kvm_cpuid(function, *eax, *ebx, *ecx, *edx, entry_found);
|
|
return entry_found;
|
|
}
|
|
EXPORT_SYMBOL_GPL(kvm_cpuid);
|
|
|
|
int kvm_emulate_cpuid(struct kvm_vcpu *vcpu)
|
|
{
|
|
u32 eax, ebx, ecx, edx;
|
|
|
|
if (cpuid_fault_enabled(vcpu) && !kvm_require_cpl(vcpu, 0))
|
|
return 1;
|
|
|
|
eax = kvm_register_read(vcpu, VCPU_REGS_RAX);
|
|
ecx = kvm_register_read(vcpu, VCPU_REGS_RCX);
|
|
kvm_cpuid(vcpu, &eax, &ebx, &ecx, &edx, true);
|
|
kvm_register_write(vcpu, VCPU_REGS_RAX, eax);
|
|
kvm_register_write(vcpu, VCPU_REGS_RBX, ebx);
|
|
kvm_register_write(vcpu, VCPU_REGS_RCX, ecx);
|
|
kvm_register_write(vcpu, VCPU_REGS_RDX, edx);
|
|
return kvm_skip_emulated_instruction(vcpu);
|
|
}
|
|
EXPORT_SYMBOL_GPL(kvm_emulate_cpuid);
|