diff options
| -rw-r--r-- | arch/x86/kvm/mmu/mmu.c | 20 |
1 files changed, 17 insertions, 3 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 690f560341a2..00732757cc60 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -4174,13 +4174,28 @@ __reset_rsvds_bits_mask(struct rsvd_bits_validate *rsvd_check, } } +static bool guest_can_use_gbpages(struct kvm_vcpu *vcpu) +{ + /* + * If TDP is enabled, let the guest use GBPAGES if they're supported in + * hardware. The hardware page walker doesn't let KVM disable GBPAGES, + * i.e. won't treat them as reserved, and KVM doesn't redo the GVA->GPA + * walk for performance and complexity reasons. Not to mention KVM + * _can't_ solve the problem because GVA->GPA walks aren't visible to + * KVM once a TDP translation is installed. Mimic hardware behavior so + * that KVM's is at least consistent, i.e. doesn't randomly inject #PF. + */ + return tdp_enabled ? boot_cpu_has(X86_FEATURE_GBPAGES) : + guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES); +} + static void reset_rsvds_bits_mask(struct kvm_vcpu *vcpu, struct kvm_mmu *context) { __reset_rsvds_bits_mask(&context->guest_rsvd_check, vcpu->arch.reserved_gpa_bits, context->root_level, is_efer_nx(context), - guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES), + guest_can_use_gbpages(vcpu), is_cr4_pse(context), guest_cpuid_is_amd_or_hygon(vcpu)); } @@ -4259,8 +4274,7 @@ static void reset_shadow_zero_bits_mask(struct kvm_vcpu *vcpu, shadow_zero_check = &context->shadow_zero_check; __reset_rsvds_bits_mask(shadow_zero_check, reserved_hpa_bits(), context->shadow_root_level, uses_nx, - guest_cpuid_has(vcpu, X86_FEATURE_GBPAGES), - is_pse, is_amd); + guest_can_use_gbpages(vcpu), is_pse, is_amd); if (!shadow_me_mask) return; |