From 8225804259b165300d2d1cc1c4bdbad32fadf6da Mon Sep 17 00:00:00 2001 From: Ladi Prosek Date: Tue, 10 Oct 2017 14:02:51 +0200 Subject: [PATCH 13/69] i386/kvm: advertise Hyper-V frequency MSRs RH-Author: Ladi Prosek Message-id: <20171010140251.23801-5-lprosek@redhat.com> Patchwork-id: 77063 O-Subject: [RHV7.5 qemu-kvm-rhev PATCH 4/4] i386/kvm: advertise Hyper-V frequency MSRs Bugzilla: 1500347 RH-Acked-by: Paolo Bonzini RH-Acked-by: David Hildenbrand RH-Acked-by: Laszlo Ersek 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 Reviewed-by: David Hildenbrand Message-Id: <20170807085703.32267-5-lprosek@redhat.com> Signed-off-by: Paolo Bonzini (cherry picked from commit d72bc7f6f8a397790abee4a25ba1b8c35dd2b841) Signed-off-by: Ladi Prosek Signed-off-by: Miroslav Rezanina --- target/i386/kvm.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 2dc01c9..739334a 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; } } } -- 1.8.3.1