Sean Christopherson <seanjc@xxxxxxxxxx> writes: > On Thu, Oct 13, 2022, Vitaly Kuznetsov wrote: >> Normally, genuine Hyper-V doesn't expose architectural invariant TSC >> (CPUID.80000007H:EDX[8]) to its guests by default. A special PV MSR >> (HV_X64_MSR_TSC_INVARIANT_CONTROL, 0x40000118) and corresponding CPUID >> feature bit (CPUID.0x40000003.EAX[15]) were introduced. When bit 0 of the >> PV MSR is set, invariant TSC bit starts to show up in CPUID. When the >> feature is exposed to Hyper-V guests, reenlightenment becomes unneeded. >> >> Note: strictly speaking, KVM doesn't have to have the feature as exposing >> raw invariant TSC bit (CPUID.80000007H:EDX[8]) also seems to work for >> modern Windows versions. The feature is, however, tiny and straitforward >> and gives additional flexibility so why not. >> >> Vitaly Kuznetsov (7): >> x86/hyperv: Add HV_EXPOSE_INVARIANT_TSC define >> KVM: x86: Add a KVM-only leaf for CPUID_8000_0007_EDX >> KVM: x86: Hyper-V invariant TSC control >> KVM: selftests: Rename 'msr->available' to 'msr->fault_exepected' in >> hyperv_features test >> KVM: selftests: Convert hyperv_features test to using >> KVM_X86_CPU_FEATURE() >> KVM: selftests: Test that values written to Hyper-V MSRs are preserved >> KVM: selftests: Test Hyper-V invariant TSC control > > For the series, in case Paolo ends up grabbing this: > > Reviewed-by: Sean Christopherson <seanjc@xxxxxxxxxx> > I completely forgot about this one! Any chance it can still be queueed for 6.2? Thanks! -- Vitaly
