diff options
| author | Sean Christopherson <seanjc@google.com> | 2023-08-15 13:36:47 -0700 |
|---|---|---|
| committer | Sean Christopherson <seanjc@google.com> | 2023-08-17 11:43:28 -0700 |
| commit | 4365a45571c791a2fbeb81cf27738960c5456f57 (patch) | |
| tree | 8963d912fde7ac18ed978010c41cd4a934f1ebae /arch/x86 | |
| parent | 7a6a6a3bf5d8c32a91d8fabb0e2d31f3bd23a412 (diff) | |
KVM: nSVM: Use KVM-governed feature framework to track "TSC scaling enabled"
Track "TSC scaling exposed to L1" via a governed feature flag instead of
using a dedicated bit/flag in vcpu_svm.
Note, this fixes a benign bug where KVM would mark TSC scaling as exposed
to L1 even if overall nested SVM supported is disabled, i.e. KVM would let
L1 write MSR_AMD64_TSC_RATIO even when KVM didn't advertise TSCRATEMSR
support to userspace.
Reviewed-by: Yuan Yao <yuan.yao@intel.com>
Link: https://lore.kernel.org/r/20230815203653.519297-10-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kvm/governed_features.h | 1 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/nested.c | 2 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 10 | ||||
| -rw-r--r-- | arch/x86/kvm/svm/svm.h | 1 |
4 files changed, 8 insertions, 6 deletions
diff --git a/arch/x86/kvm/governed_features.h b/arch/x86/kvm/governed_features.h index 722b66af412c..32c0469cf952 100644 --- a/arch/x86/kvm/governed_features.h +++ b/arch/x86/kvm/governed_features.h @@ -9,6 +9,7 @@ KVM_GOVERNED_X86_FEATURE(GBPAGES) KVM_GOVERNED_X86_FEATURE(XSAVES) KVM_GOVERNED_X86_FEATURE(VMX) KVM_GOVERNED_X86_FEATURE(NRIPS) +KVM_GOVERNED_X86_FEATURE(TSCRATEMSR) #undef KVM_GOVERNED_X86_FEATURE #undef KVM_GOVERNED_FEATURE diff --git a/arch/x86/kvm/svm/nested.c b/arch/x86/kvm/svm/nested.c index 9092f3f8dccf..da65948064dc 100644 --- a/arch/x86/kvm/svm/nested.c +++ b/arch/x86/kvm/svm/nested.c @@ -695,7 +695,7 @@ static void nested_vmcb02_prepare_control(struct vcpu_svm *svm, vmcb02->control.tsc_offset = vcpu->arch.tsc_offset; - if (svm->tsc_scaling_enabled && + if (guest_can_use(vcpu, X86_FEATURE_TSCRATEMSR) && svm->tsc_ratio_msr != kvm_caps.default_tsc_scaling_ratio) nested_svm_update_tsc_ratio_msr(vcpu); diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index de69e98a7c6a..0d5cca0bb5fb 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -2795,7 +2795,8 @@ static int svm_get_msr(struct kvm_vcpu *vcpu, struct msr_data *msr_info) switch (msr_info->index) { case MSR_AMD64_TSC_RATIO: - if (!msr_info->host_initiated && !svm->tsc_scaling_enabled) + if (!msr_info->host_initiated && + !guest_can_use(vcpu, X86_FEATURE_TSCRATEMSR)) return 1; msr_info->data = svm->tsc_ratio_msr; break; @@ -2937,7 +2938,7 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) switch (ecx) { case MSR_AMD64_TSC_RATIO: - if (!svm->tsc_scaling_enabled) { + if (!guest_can_use(vcpu, X86_FEATURE_TSCRATEMSR)) { if (!msr->host_initiated) return 1; @@ -2959,7 +2960,8 @@ static int svm_set_msr(struct kvm_vcpu *vcpu, struct msr_data *msr) svm->tsc_ratio_msr = data; - if (svm->tsc_scaling_enabled && is_guest_mode(vcpu)) + if (guest_can_use(vcpu, X86_FEATURE_TSCRATEMSR) && + is_guest_mode(vcpu)) nested_svm_update_tsc_ratio_msr(vcpu); break; @@ -4260,8 +4262,8 @@ static void svm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu) kvm_governed_feature_set(vcpu, X86_FEATURE_XSAVES); kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_NRIPS); + kvm_governed_feature_check_and_set(vcpu, X86_FEATURE_TSCRATEMSR); - svm->tsc_scaling_enabled = tsc_scaling && guest_cpuid_has(vcpu, X86_FEATURE_TSCRATEMSR); svm->lbrv_enabled = lbrv && guest_cpuid_has(vcpu, X86_FEATURE_LBRV); svm->v_vmload_vmsave_enabled = vls && guest_cpuid_has(vcpu, X86_FEATURE_V_VMSAVE_VMLOAD); diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h index c06de55425d4..4e7332f77702 100644 --- a/arch/x86/kvm/svm/svm.h +++ b/arch/x86/kvm/svm/svm.h @@ -259,7 +259,6 @@ struct vcpu_svm { bool soft_int_injected; /* optional nested SVM features that are enabled for this guest */ - bool tsc_scaling_enabled : 1; bool v_vmload_vmsave_enabled : 1; bool lbrv_enabled : 1; bool pause_filter_enabled : 1; |