Sean Christopherson <seanjc@xxxxxxxxxx> writes: > On Thu, Dec 16, 2021, Vitaly Kuznetsov wrote: >> Sean Christopherson <seanjc@xxxxxxxxxx> writes: >> > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >> > index 85127b3e3690..65e297875405 100644 >> > --- a/arch/x86/kvm/x86.c >> > +++ b/arch/x86/kvm/x86.c >> > @@ -3424,7 +3424,7 @@ int kvm_set_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) >> > >> > if (!msr_info->host_initiated) >> > return 1; >> > - if (guest_cpuid_has(vcpu, X86_FEATURE_PDCM) && kvm_get_msr_feature(&msr_ent)) >> > + if (kvm_get_msr_feature(&msr_ent)) >> > return 1; >> > if (data & ~msr_ent.data) >> > return 1; >> >> This looks OK. >> >> > @@ -3779,14 +3779,12 @@ int kvm_get_msr_common(struct kvm_vcpu *vcpu, struct msr_data *msr_info) >> > msr_info->data = vcpu->arch.microcode_version; >> > break; >> > case MSR_IA32_ARCH_CAPABILITIES: >> > - if (!msr_info->host_initiated && >> > - !guest_cpuid_has(vcpu, X86_FEATURE_ARCH_CAPABILITIES)) >> > + if (!msr_info->host_initiated) >> > return 1; >> > msr_info->data = vcpu->arch.arch_capabilities; >> > break; >> > case MSR_IA32_PERF_CAPABILITIES: >> > - if (!msr_info->host_initiated && >> > - !guest_cpuid_has(vcpu, X86_FEATURE_PDCM)) >> > + if (!msr_info->host_initiated) >> > return 1; >> > msr_info->data = vcpu->arch.perf_capabilities; >> > break; >> > >> >> Hm, this change will unconditionally forbid reading >> MSR_IA32_ARCH_CAPABILITIES/MSR_IA32_PERF_CAPABILITIES from the guest. Is >> this what we want? > > No, I completely misread the code. The kvm_set_msr_common() goof seems to be > the only bug, and that would also explain the selftest's bad testcase. > Ok then, v2 is coming. -- Vitaly
