On Tue, Mar 20, 2018 at 06:34:59PM +0100, Vitaly Kuznetsov wrote: > KVM recently gained support for Hyper-V Reenlightenment MSRs which are > required to make KVM-on-Hyper-V enable TSC page clocksource to its guests > when INVTSC is not passed to it (and it is not passed by default in Qemu > as it effectively blocks migration). > > Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com> > --- > Changes since v2: > - add hv-reenlightenment CPU property [Roman Kagan, Paolo Bonzini] > - add a comment to feature_word_info [Roman Kagan] > --- > target/i386/cpu.c | 4 +++- > target/i386/cpu.h | 4 ++++ > target/i386/hyperv-proto.h | 9 ++++++++- > target/i386/kvm.c | 39 ++++++++++++++++++++++++++++++++++++++- > target/i386/machine.c | 24 ++++++++++++++++++++++++ > 5 files changed, 77 insertions(+), 3 deletions(-) > > diff --git a/target/i386/cpu.c b/target/i386/cpu.c > index 6bb4ce8719..02579f8234 100644 > --- a/target/i386/cpu.c > +++ b/target/i386/cpu.c > @@ -407,7 +407,8 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = > { > NULL /* hv_vpindex_access */, NULL /* hv_msr_reset_access */, > NULL /* hv_msr_stats_access */, NULL /* hv_reftsc_access */, > NULL /* hv_msr_idle_access */, NULL /* hv_msr_frequency_access > */, > - NULL, NULL, NULL, NULL, > + NULL /* hv_msr_debug_access */, NULL /* > hv_msr_reenlightenment_access */, > + NULL, NULL, > NULL, NULL, NULL, NULL, > NULL, NULL, NULL, NULL, > NULL, NULL, NULL, NULL, > @@ -4764,6 +4765,7 @@ static Property x86_cpu_properties[] = { > DEFINE_PROP_BOOL("hv-runtime", X86CPU, hyperv_runtime, false), > DEFINE_PROP_BOOL("hv-synic", X86CPU, hyperv_synic, false), > DEFINE_PROP_BOOL("hv-stimer", X86CPU, hyperv_stimer, false), > + DEFINE_PROP_BOOL("hv-reenlightenment", X86CPU, hyperv_reenlightenment, > false), > DEFINE_PROP_BOOL("check", X86CPU, check_cpuid, true), > DEFINE_PROP_BOOL("enforce", X86CPU, enforce_cpuid, false), > DEFINE_PROP_BOOL("kvm", X86CPU, expose_kvm, true), > diff --git a/target/i386/cpu.h b/target/i386/cpu.h > index 2e2bab5ff3..98eed72937 100644 > --- a/target/i386/cpu.h > +++ b/target/i386/cpu.h > @@ -1174,6 +1174,9 @@ typedef struct CPUX86State { > uint64_t msr_hv_synic_sint[HV_SINT_COUNT]; > uint64_t msr_hv_stimer_config[HV_STIMER_COUNT]; > uint64_t msr_hv_stimer_count[HV_STIMER_COUNT]; > + uint64_t msr_hv_reenlightenment_control; > + uint64_t msr_hv_tsc_emulation_control; > + uint64_t msr_hv_tsc_emulation_status; > > uint64_t msr_rtit_ctrl; > uint64_t msr_rtit_status; > @@ -1296,6 +1299,7 @@ struct X86CPU { > bool hyperv_runtime; > bool hyperv_synic; > bool hyperv_stimer; > + bool hyperv_reenlightenment; > bool check_cpuid; > bool enforce_cpuid; > bool expose_kvm; > diff --git a/target/i386/hyperv-proto.h b/target/i386/hyperv-proto.h > index cb4d7f2b7a..93352ebd2a 100644 > --- a/target/i386/hyperv-proto.h > +++ b/target/i386/hyperv-proto.h > @@ -35,7 +35,7 @@ > #define HV_RESET_AVAILABLE (1u << 7) > #define HV_REFERENCE_TSC_AVAILABLE (1u << 9) > #define HV_ACCESS_FREQUENCY_MSRS (1u << 11) > - > +#define HV_ACCESS_REENLIGHTENMENTS_CONTROL (1u << 13) > > /* > * HV_CPUID_FEATURES.EDX bits > @@ -129,6 +129,13 @@ > #define HV_X64_MSR_CRASH_CTL 0x40000105 > #define HV_CRASH_CTL_NOTIFY (1ull << 63) > > +/* > + * Reenlightenment notification MSRs > + */ > +#define HV_X64_MSR_REENLIGHTENMENT_CONTROL 0x40000106 > +#define HV_X64_MSR_TSC_EMULATION_CONTROL 0x40000107 > +#define HV_X64_MSR_TSC_EMULATION_STATUS 0x40000108 > + > /* > * Hypercall status code > */ > diff --git a/target/i386/kvm.c b/target/i386/kvm.c > index d23fff12f5..7d9f9ca0b1 100644 > --- a/target/i386/kvm.c > +++ b/target/i386/kvm.c > @@ -90,6 +90,7 @@ 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_hv_reenlightenment; > static bool has_msr_xss; > static bool has_msr_spec_ctrl; > static bool has_msr_smi_count; > @@ -583,7 +584,8 @@ static bool hyperv_enabled(X86CPU *cpu) > cpu->hyperv_vpindex || > cpu->hyperv_runtime || > cpu->hyperv_synic || > - cpu->hyperv_stimer); > + cpu->hyperv_stimer || > + cpu->hyperv_reenlightenment); > } > > static int kvm_arch_set_tsc_khz(CPUState *cs) > @@ -654,6 +656,14 @@ static int hyperv_handle_properties(CPUState *cs) > env->features[FEAT_HYPERV_EDX] |= HV_FREQUENCY_MSRS_AVAILABLE; > } > } > + if (cpu->hyperv_reenlightenment) { > + if (!has_msr_hv_reenlightenment) { > + fprintf(stderr, > + "Hyper-V Reenlightenment is not supported by kernel\n"); > + return -ENOSYS; > + } > + env->features[FEAT_HYPERV_EAX] |= HV_ACCESS_REENLIGHTENMENTS_CONTROL; > + } > if (cpu->hyperv_crash && has_msr_hv_crash) { > env->features[FEAT_HYPERV_EDX] |= HV_GUEST_CRASH_MSR_AVAILABLE; > } > @@ -1185,6 +1195,9 @@ static int kvm_get_supported_msrs(KVMState *s) > case HV_X64_MSR_TSC_FREQUENCY: > has_msr_hv_frequencies = true; > break; > + case HV_X64_MSR_REENLIGHTENMENT_CONTROL: > + has_msr_hv_reenlightenment = true; > + break; > case MSR_IA32_SPEC_CTRL: > has_msr_spec_ctrl = true; > break; > @@ -1747,6 +1760,15 @@ static int kvm_put_msrs(X86CPU *cpu, int level) > if (cpu->hyperv_time) { > kvm_msr_entry_add(cpu, HV_X64_MSR_REFERENCE_TSC, > env->msr_hv_tsc); > + > + if (has_msr_hv_reenlightenment) { > + kvm_msr_entry_add(cpu, > HV_X64_MSR_REENLIGHTENMENT_CONTROL, > + env->msr_hv_reenlightenment_control); > + kvm_msr_entry_add(cpu, HV_X64_MSR_TSC_EMULATION_CONTROL, > + env->msr_hv_tsc_emulation_control); > + kvm_msr_entry_add(cpu, HV_X64_MSR_TSC_EMULATION_STATUS, > + env->msr_hv_tsc_emulation_status); > + }
I second Eduardo's comment on testing cpu->hyperv_reenlightenment here. Besides, this hunk suggests that (!cpu->hyperv_time && cpu->hyperv_reenlightenment) is illegal. I think this should be enforced when enabling the feature. BTW this also makes the addition to hyperv_enabled() unnecessary. Thanks, Roman.