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| author | Ladi Prosek | 2017-08-07 10:57:03 +0200 |
|---|---|---|
| committer | Paolo Bonzini | 2017-09-19 14:09:33 +0200 |
| commit | d72bc7f6f8a397790abee4a25ba1b8c35dd2b841 (patch) | |
| tree | ae611f5b69b997a2f71f63e2b5c5fad9eba2ba7c /target/i386/kvm.c | |
| parent | i386/kvm: introduce tsc_is_stable_and_known() (diff) | |
| download | qemu-d72bc7f6f8a397790abee4a25ba1b8c35dd2b841.tar.gz qemu-d72bc7f6f8a397790abee4a25ba1b8c35dd2b841.tar.xz qemu-d72bc7f6f8a397790abee4a25ba1b8c35dd2b841.zip | |
i386/kvm: advertise Hyper-V frequency MSRs
As of kernel commit eb82feea59d6 ("KVM: hyperv: support HV_X64_MSR_TSC_FREQUENCY
and HV_X64_MSR_APIC_FREQUENCY"), KVM supports two new MSRs which are required
for nested Hyper-V to read timestamps with RDTSC + TSC page.
This commit makes QEMU advertise the MSRs with CPUID.40000003H:EAX[11] and
CPUID.40000003H:EDX[8] as specified in the Hyper-V TLFS and experimentally
verified on a Hyper-V host. The feature is enabled with the existing hv-time CPU
flag, and only if the TSC frequency is stable across migrations and known.
Signed-off-by: Ladi Prosek <lprosek@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Message-Id: <20170807085703.32267-5-lprosek@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'target/i386/kvm.c')
| -rw-r--r-- | target/i386/kvm.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 2dc01c9973..739334a5a6 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -89,6 +89,7 @@ static bool has_msr_hv_vpindex; static bool has_msr_hv_runtime; static bool has_msr_hv_synic; static bool has_msr_hv_stimer; +static bool has_msr_hv_frequencies; static bool has_msr_xss; static bool has_msr_architectural_pmu; @@ -640,7 +641,13 @@ static int hyperv_handle_properties(CPUState *cs) if (cpu->hyperv_time) { env->features[FEAT_HYPERV_EAX] |= HV_X64_MSR_HYPERCALL_AVAILABLE; env->features[FEAT_HYPERV_EAX] |= HV_X64_MSR_TIME_REF_COUNT_AVAILABLE; - env->features[FEAT_HYPERV_EAX] |= 0x200; + env->features[FEAT_HYPERV_EAX] |= HV_X64_MSR_REFERENCE_TSC_AVAILABLE; + + if (has_msr_hv_frequencies && tsc_is_stable_and_known(env)) { + env->features[FEAT_HYPERV_EAX] |= HV_X64_ACCESS_FREQUENCY_MSRS; + env->features[FEAT_HYPERV_EDX] |= + HV_FEATURE_FREQUENCY_MSRS_AVAILABLE; + } } if (cpu->hyperv_crash && has_msr_hv_crash) { env->features[FEAT_HYPERV_EDX] |= HV_X64_GUEST_CRASH_MSR_AVAILABLE; @@ -1134,6 +1141,9 @@ static int kvm_get_supported_msrs(KVMState *s) case HV_X64_MSR_STIMER0_CONFIG: has_msr_hv_stimer = true; break; + case HV_X64_MSR_TSC_FREQUENCY: + has_msr_hv_frequencies = true; + break; } } } |