diff options
| author | Sean Christopherson <[email protected]> | 2024-08-02 11:55:05 -0700 |
|---|---|---|
| committer | Sean Christopherson <[email protected]> | 2024-11-01 09:22:31 -0700 |
| commit | dcb988cdac85bad177de86fbf409524eda4f9467 (patch) | |
| tree | 568a19ac2ef88c59979327c44f8e0d5390313bd4 /arch/x86/kvm/svm/svm.c | |
| parent | bc2ca3680b30869ee9a764ab72c143070f1afec8 (diff) | |
KVM: x86: Quirk initialization of feature MSRs to KVM's max configuration
Add a quirk to control KVM's misguided initialization of select feature
MSRs to KVM's max configuration, as enabling features by default violates
KVM's approach of letting userspace own the vCPU model, and is actively
problematic for MSRs that are conditionally supported, as the vCPU will
end up with an MSR value that userspace can't restore. E.g. if the vCPU
is configured with PDCM=0, userspace will save and attempt to restore a
non-zero PERF_CAPABILITIES, thanks to KVM's meddling.
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Sean Christopherson <[email protected]>
Diffstat (limited to 'arch/x86/kvm/svm/svm.c')
| -rw-r--r-- | arch/x86/kvm/svm/svm.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index 50f6b0e03d04..237e72b8a999 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -1390,7 +1390,9 @@ static void __svm_vcpu_reset(struct kvm_vcpu *vcpu) svm_vcpu_init_msrpm(vcpu, svm->msrpm); svm_init_osvw(vcpu); - vcpu->arch.microcode_version = 0x01000065; + + if (kvm_check_has_quirk(vcpu->kvm, KVM_X86_QUIRK_STUFF_FEATURE_MSRS)) + vcpu->arch.microcode_version = 0x01000065; svm->tsc_ratio_msr = kvm_caps.default_tsc_scaling_ratio; svm->nmi_masked = false; |