Hyper-V on KVM can only use Synthetic timers with Direct Mode (opting for an interrupt instead of VMBus message). This new capability is only announced in KVM_GET_SUPPORTED_HV_CPUID.
Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com> --- docs/hyperv.txt | 10 ++++++++++ target/i386/cpu.c | 1 + target/i386/cpu.h | 1 + target/i386/hyperv-proto.h | 1 + target/i386/kvm.c | 15 +++++++++++++++ 5 files changed, 28 insertions(+) diff --git a/docs/hyperv.txt b/docs/hyperv.txt index d1299aba81..e1988ab648 100644 --- a/docs/hyperv.txt +++ b/docs/hyperv.txt @@ -173,6 +173,16 @@ without the feature to find out if enabling it is beneficial. Requires: hv-vapic +3.17. hv-stimer-direct +======================= +Hyper-V specification allows synthetic timer operation in two modes: "classic", +when expiration event is delivered as SynIC message and "direct", when the event +is delivered via normal interrupt. It is known that nested Hyper-V can only +use synthetic timers in direct mode and thus 'hv-stimer-direct' needs to be +enabled. + +Requires: hv-vpindex, hv-synic, hv-time, hv-stimer + 4. Development features ======================== diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 4e01ad076e..ea3843ed0c 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -5785,6 +5785,7 @@ static Property x86_cpu_properties[] = { DEFINE_PROP_BOOL("hv-tlbflush", X86CPU, hyperv_tlbflush, false), DEFINE_PROP_BOOL("hv-evmcs", X86CPU, hyperv_evmcs, false), DEFINE_PROP_BOOL("hv-ipi", X86CPU, hyperv_ipi, false), + DEFINE_PROP_BOOL("hv-stimer-direct", X86CPU, hyperv_stimer_direct, false), DEFINE_PROP_BOOL("hv-all", X86CPU, hyperv_all, false), DEFINE_PROP_BOOL("check", X86CPU, check_cpuid, true), DEFINE_PROP_BOOL("enforce", X86CPU, enforce_cpuid, false), diff --git a/target/i386/cpu.h b/target/i386/cpu.h index 9cd3a8bc2f..3f1ada3e39 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -1396,6 +1396,7 @@ struct X86CPU { bool hyperv_tlbflush; bool hyperv_evmcs; bool hyperv_ipi; + bool hyperv_stimer_direct; bool hyperv_all; bool check_cpuid; bool enforce_cpuid; diff --git a/target/i386/hyperv-proto.h b/target/i386/hyperv-proto.h index c0272b3a01..cffac10b45 100644 --- a/target/i386/hyperv-proto.h +++ b/target/i386/hyperv-proto.h @@ -49,6 +49,7 @@ #define HV_GUEST_IDLE_STATE_AVAILABLE (1u << 5) #define HV_FREQUENCY_MSRS_AVAILABLE (1u << 8) #define HV_GUEST_CRASH_MSR_AVAILABLE (1u << 10) +#define HV_STIMER_DIRECT_MODE_AVAILABLE (1u << 19) /* * HV_CPUID_ENLIGHTMENT_INFO.EAX bits diff --git a/target/i386/kvm.c b/target/i386/kvm.c index 976c1d570f..f3c73b7c4e 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -657,6 +657,7 @@ static bool hyperv_enabled(X86CPU *cpu) cpu->hyperv_reenlightenment || cpu->hyperv_tlbflush || cpu->hyperv_ipi || + cpu->hyperv_stimer_direct || cpu->hyperv_all); } @@ -832,6 +833,15 @@ static struct { {0} } }, + { + .name = "hv-stimer-direct", + .desc = "direct mode timers", + .flags = { + {.fw = FEAT_HYPERV_EDX, + .bits = HV_STIMER_DIRECT_MODE_AVAILABLE}, + {0} + } + }, }; static struct kvm_cpuid2 *try_get_hv_cpuid(CPUState *cs, int max) @@ -1178,6 +1188,8 @@ static int hyperv_handle_properties(CPUState *cs, r |= hv_cpuid_check_and_set(cs, cpuid, "hv-tlbflush", &cpu->hyperv_tlbflush); r |= hv_cpuid_check_and_set(cs, cpuid, "hv-ipi", &cpu->hyperv_ipi); + r |= hv_cpuid_check_and_set(cs, cpuid, "hv-stimer-direct", + &cpu->hyperv_stimer_direct); /* Dependencies */ if (cpu->hyperv_synic && !cpu->hyperv_synic_kvm_only && @@ -1198,6 +1210,9 @@ static int hyperv_handle_properties(CPUState *cs, if (cpu->hyperv_ipi && !cpu->hyperv_vpindex) { r |= hv_report_missing_dep(cpu, "hv-ipi", "hv-vpindex"); } + if (cpu->hyperv_stimer_direct && !cpu->hyperv_stimer) { + r |= hv_report_missing_dep(cpu, "hv-stimer-direct", "hv-stimer"); + } /* Not exposed by KVM but needed to make CPU hotplug in Windows work */ env->features[FEAT_HYPERV_EDX] |= HV_CPU_DYNAMIC_PARTITIONING_AVAILABLE; -- 2.20.1