Messages in this thread Patch in this message | | | Date | Thu, 21 Jul 2022 21:43:29 +0000 | From | Sean Christopherson <> | Subject | Re: [PATCH v4 01/25] KVM: x86: hyper-v: Expose access to debug MSRs in the partition privilege flags |
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On Thu, Jul 14, 2022, Vitaly Kuznetsov wrote: > For some features, Hyper-V spec defines two separate CPUID bits: one > listing whether the feature is supported or not and another one showing > whether guest partition was granted access to the feature ("partition > privilege mask"). 'Debug MSRs available' is one of such features. Add > the missing 'access' bit. > > Fixes: f97f5a56f597 ("x86/kvm/hyper-v: Add support for synthetic debugger interface") > Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com> > Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> > --- > arch/x86/kvm/hyperv.c | 1 + > include/asm-generic/hyperv-tlfs.h | 2 ++ > 2 files changed, 3 insertions(+) > > diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c > index e2e95a6fccfd..e08189211d9a 100644 > --- a/arch/x86/kvm/hyperv.c > +++ b/arch/x86/kvm/hyperv.c > @@ -2496,6 +2496,7 @@ int kvm_get_hv_cpuid(struct kvm_vcpu *vcpu, struct kvm_cpuid2 *cpuid, > ent->eax |= HV_MSR_RESET_AVAILABLE; > ent->eax |= HV_MSR_REFERENCE_TSC_AVAILABLE; > ent->eax |= HV_ACCESS_FREQUENCY_MSRS; > + ent->eax |= HV_ACCESS_DEBUG_MSRS; > ent->eax |= HV_ACCESS_REENLIGHTENMENT;
Doesn't KVM also need to switch to enforcing the "access" flag?
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c index c284a605e453..ca91547034e4 100644 --- a/arch/x86/kvm/hyperv.c +++ b/arch/x86/kvm/hyperv.c @@ -1282,7 +1282,7 @@ static bool hv_check_msr_access(struct kvm_vcpu_hv *hv_vcpu, u32 msr) case HV_X64_MSR_SYNDBG_OPTIONS: case HV_X64_MSR_SYNDBG_CONTROL ... HV_X64_MSR_SYNDBG_PENDING_BUFFER: return hv_vcpu->cpuid_cache.features_edx & - HV_FEATURE_DEBUG_MSRS_AVAILABLE; + HV_ACCESS_DEBUG_MSRS; default: break; }
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