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| author | Vitaly Kuznetsov <vkuznets@redhat.com> | 2022-05-25 13:59:45 +0200 |
|---|---|---|
| committer | Paolo Bonzini <pbonzini@redhat.com> | 2022-05-25 21:26:35 +0200 |
| commit | 869840d26c929b99694e31b1a18e83bdea6e97ca (patch) | |
| tree | 8d3be5755ce10f0b75bce56d99aa09de39dd6ca1 | |
| parent | 7110fe56c1f69b9e1bdf838558fdcb75d1568964 (diff) | |
| download | qemu-869840d26c929b99694e31b1a18e83bdea6e97ca.zip qemu-869840d26c929b99694e31b1a18e83bdea6e97ca.tar.gz qemu-869840d26c929b99694e31b1a18e83bdea6e97ca.tar.bz2 | |
i386: Hyper-V Enlightened MSR bitmap feature
The newly introduced enlightenment allow L0 (KVM) and L1 (Hyper-V)
hypervisors to collaborate to avoid unnecessary updates to L2
MSR-Bitmap upon vmexits.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20220525115949.1294004-3-vkuznets@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
| -rw-r--r-- | docs/hyperv.txt | 9 | ||||
| -rw-r--r-- | target/i386/cpu.c | 2 | ||||
| -rw-r--r-- | target/i386/cpu.h | 1 | ||||
| -rw-r--r-- | target/i386/kvm/hyperv-proto.h | 5 | ||||
| -rw-r--r-- | target/i386/kvm/kvm.c | 7 |
5 files changed, 24 insertions, 0 deletions
diff --git a/docs/hyperv.txt b/docs/hyperv.txt index 33588a0..5d85569 100644 --- a/docs/hyperv.txt +++ b/docs/hyperv.txt @@ -239,6 +239,15 @@ This enlightenment requires a VMBus device (-device vmbus-bridge,irq=15) and the follow enlightenments to work: hv-relaxed,hv_time,hv-vapic,hv-vpindex,hv-synic,hv-runtime,hv-stimer +3.22. hv-emsr-bitmap +===================== +The enlightenment is nested specific, it targets Hyper-V on KVM guests. When +enabled, it allows L0 (KVM) and L1 (Hyper-V) hypervisors to collaborate to +avoid unnecessary updates to L2 MSR-Bitmap upon vmexits. While the protocol is +supported for both VMX (Intel) and SVM (AMD), the VMX implementation requires +Enlightened VMCS ('hv-evmcs') feature to also be enabled. + +Recommended: hv-evmcs (Intel) 4. Supplementary features ========================= diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 3856914..474e9b5 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -6968,6 +6968,8 @@ static Property x86_cpu_properties[] = { HYPERV_FEAT_STIMER_DIRECT, 0), DEFINE_PROP_BIT64("hv-avic", X86CPU, hyperv_features, HYPERV_FEAT_AVIC, 0), + DEFINE_PROP_BIT64("hv-emsr-bitmap", X86CPU, hyperv_features, + HYPERV_FEAT_MSR_BITMAP, 0), DEFINE_PROP_ON_OFF_AUTO("hv-no-nonarch-coresharing", X86CPU, hyperv_no_nonarch_cs, ON_OFF_AUTO_OFF), DEFINE_PROP_BIT64("hv-syndbg", X86CPU, hyperv_features, diff --git a/target/i386/cpu.h b/target/i386/cpu.h index 2e918da..c788285 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -1106,6 +1106,7 @@ uint64_t x86_cpu_get_supported_feature_word(FeatureWord w, #define HYPERV_FEAT_STIMER_DIRECT 14 #define HYPERV_FEAT_AVIC 15 #define HYPERV_FEAT_SYNDBG 16 +#define HYPERV_FEAT_MSR_BITMAP 17 #ifndef HYPERV_SPINLOCK_NEVER_NOTIFY #define HYPERV_SPINLOCK_NEVER_NOTIFY 0xFFFFFFFF diff --git a/target/i386/kvm/hyperv-proto.h b/target/i386/kvm/hyperv-proto.h index e40e594..cea18db 100644 --- a/target/i386/kvm/hyperv-proto.h +++ b/target/i386/kvm/hyperv-proto.h @@ -87,6 +87,11 @@ #define HV_SYNDBG_CAP_ALLOW_KERNEL_DEBUGGING (1u << 1) /* + * HV_CPUID_NESTED_FEATURES.EAX bits + */ +#define HV_NESTED_MSR_BITMAP (1u << 19) + +/* * Basic virtualized MSRs */ #define HV_X64_MSR_GUEST_OS_ID 0x40000000 diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c index 38af0e4..f389bbe 100644 --- a/target/i386/kvm/kvm.c +++ b/target/i386/kvm/kvm.c @@ -973,6 +973,13 @@ static struct { .dependencies = BIT(HYPERV_FEAT_SYNIC) | BIT(HYPERV_FEAT_RELAXED) }, #endif + [HYPERV_FEAT_MSR_BITMAP] = { + .desc = "enlightened MSR-Bitmap (hv-emsr-bitmap)", + .flags = { + {.func = HV_CPUID_NESTED_FEATURES, .reg = R_EAX, + .bits = HV_NESTED_MSR_BITMAP} + } + }, }; static struct kvm_cpuid2 *try_get_hv_cpuid(CPUState *cs, int max, |