Changes since v4:
- s,HV_INVARIANT_TSC_EXPOSED,HV_EXPOSE_INVARIANT_TSC, [Michael]
- Add Michael's R-b to PATCH1
- Use 'KVM-only' instead of 'scattered' in PATCH2's subject [Sean, Jim]
- Do not set CPUID_8000_0007_EDX to 'NCAPINTS + 1' explicitly [Sean]
- Use the opportunity and switch to 'true'/'false' for 'msr->write'/
'msr->fault_exepected' in 'hyperv_features' test [Sean]
- Fix HVCALL_NOTIFY_LONG_SPIN_WAIT test breakage by setting
HYPERV_CPUID_ENLIGHTMENT_INFO.EBX.
- "KVM: selftests: Test that values written to Hyper-V MSRs are
preserved" patch added [Sean]
Original description:
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
arch/x86/include/asm/hyperv-tlfs.h | 3 +
arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kernel/cpu/mshyperv.c | 2 +-
arch/x86/kvm/cpuid.c | 11 +-
arch/x86/kvm/hyperv.c | 19 +
arch/x86/kvm/hyperv.h | 27 ++
arch/x86/kvm/reverse_cpuid.h | 7 +
arch/x86/kvm/x86.c | 4 +-
.../selftests/kvm/include/x86_64/hyperv.h | 144 +++++---
.../selftests/kvm/include/x86_64/processor.h | 1 +
.../selftests/kvm/x86_64/hyperv_features.c | 330 +++++++++++-------
11 files changed, 366 insertions(+), 183 deletions(-)
--
2.37.3
