diff options
| author | Wanpeng Li <wanpengli@tencent.com> | 2018-02-09 06:15:25 -0800 |
|---|---|---|
| committer | Eduardo Habkost <ehabkost@redhat.com> | 2018-03-12 15:57:39 -0300 |
| commit | be7773268d98176489483a315d3e2323cb0615b9 (patch) | |
| tree | 04b4bf0a8a714996bac98ac8ec5af7f52edce048 /target/i386 | |
| parent | b16a54da0696efc5d91b6c3597a37a317abb5de7 (diff) | |
| download | qemu-be7773268d98176489483a315d3e2323cb0615b9.tar.gz | |
target-i386: add KVM_HINTS_DEDICATED performance hint
Add KVM_HINTS_DEDICATED performance hint, guest checks this feature bit
to determine if they run on dedicated vCPUs, allowing optimizations such
as usage of qspinlocks.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1518185725-69559-1-git-send-email-wanpengli@tencent.com>
[ehabkost: Renamed property to kvm-hint-dedicated]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Diffstat (limited to 'target/i386')
| -rw-r--r-- | target/i386/cpu.c | 14 | ||||
| -rw-r--r-- | target/i386/cpu.h | 3 | ||||
| -rw-r--r-- | target/i386/kvm.c | 4 |
3 files changed, 21 insertions, 0 deletions
diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 2c04645cea..5ea1931b7e 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -359,6 +359,20 @@ static FeatureWordInfo feature_word_info[FEATURE_WORDS] = { .cpuid_eax = KVM_CPUID_FEATURES, .cpuid_reg = R_EAX, .tcg_features = TCG_KVM_FEATURES, }, + [FEAT_KVM_HINTS] = { + .feat_names = { + "kvm-hint-dedicated", NULL, NULL, NULL, + NULL, NULL, NULL, NULL, + NULL, NULL, NULL, NULL, + NULL, NULL, NULL, NULL, + NULL, NULL, NULL, NULL, + NULL, NULL, NULL, NULL, + NULL, NULL, NULL, NULL, + NULL, NULL, NULL, NULL, + }, + .cpuid_eax = KVM_CPUID_FEATURES, .cpuid_reg = R_EDX, + .tcg_features = TCG_KVM_FEATURES, + }, [FEAT_HYPERV_EAX] = { .feat_names = { NULL /* hv_msr_vp_runtime_access */, NULL /* hv_msr_time_refcount_access */, diff --git a/target/i386/cpu.h b/target/i386/cpu.h index faf39ec1ce..8d977ec567 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -471,6 +471,7 @@ typedef enum FeatureWord { FEAT_8000_0008_EBX, /* CPUID[8000_0008].EBX */ FEAT_C000_0001_EDX, /* CPUID[C000_0001].EDX */ FEAT_KVM, /* CPUID[4000_0001].EAX (KVM_CPUID_FEATURES) */ + FEAT_KVM_HINTS, /* CPUID[4000_0001].EDX */ FEAT_HYPERV_EAX, /* CPUID[4000_0003].EAX */ FEAT_HYPERV_EBX, /* CPUID[4000_0003].EBX */ FEAT_HYPERV_EDX, /* CPUID[4000_0003].EDX */ @@ -666,6 +667,8 @@ typedef uint32_t FeatureWordArray[FEATURE_WORDS]; #define CPUID_7_0_EDX_AVX512_4FMAPS (1U << 3) /* AVX512 Multiply Accumulation Single Precision */ #define CPUID_7_0_EDX_SPEC_CTRL (1U << 26) /* Speculation Control */ +#define KVM_HINTS_DEDICATED (1U << 0) + #define CPUID_8000_0008_EBX_IBPB (1U << 12) /* Indirect Branch Prediction Barrier */ #define CPUID_XSAVE_XSAVEOPT (1U << 0) diff --git a/target/i386/kvm.c b/target/i386/kvm.c index ad4b159b28..44ee524188 100644 --- a/target/i386/kvm.c +++ b/target/i386/kvm.c @@ -383,6 +383,9 @@ uint32_t kvm_arch_get_supported_cpuid(KVMState *s, uint32_t function, if (!kvm_irqchip_in_kernel()) { ret &= ~(1U << KVM_FEATURE_PV_UNHALT); } + } else if (function == KVM_CPUID_FEATURES && reg == R_EDX) { + ret |= KVM_HINTS_DEDICATED; + found = 1; } /* fallback for older kernels */ @@ -801,6 +804,7 @@ int kvm_arch_init_vcpu(CPUState *cs) c = &cpuid_data.entries[cpuid_i++]; c->function = KVM_CPUID_FEATURES | kvm_base; c->eax = env->features[FEAT_KVM]; + c->edx = env->features[FEAT_KVM_HINTS]; } cpu_x86_cpuid(env, 0, 0, &limit, &unused, &unused, &unused); |