@@ -189,7 +189,15 @@ enabled.
Requires: hv-vpindex, hv-synic, hv-time, hv-stimer
-3.17. hv-no-nonarch-coresharing=on/off/auto
+3.18. hv-avic (hv-apicv)
+=======================
+The enlightenment allows to use Hyper-V SynIC with hardware APICv/AVIC enabled.
+Normally, Hyper-V SynIC disables these hardware feature and suggests the guest
+to use paravirtualized AutoEOI feature.
+Note: enabling this feature on old hardware (without APICv/AVIC support) may
+have negative effect on guest's performace.
+
+3.19. hv-no-nonarch-coresharing=on/off/auto
===========================================
This enlightenment tells guest OS that virtual processors will never share a
physical core unless they are reported as sibling SMT threads. This information
@@ -6477,6 +6477,8 @@ static void x86_cpu_initfn(Object *obj)
object_property_add_alias(obj, "sse4_1", obj, "sse4.1");
object_property_add_alias(obj, "sse4_2", obj, "sse4.2");
+ object_property_add_alias(obj, "hv-apicv", obj, "hv-avic");
+
if (xcc->model) {
x86_cpu_load_model(cpu, xcc->model);
}
@@ -6662,6 +6664,8 @@ static Property x86_cpu_properties[] = {
HYPERV_FEAT_IPI, 0),
DEFINE_PROP_BIT64("hv-stimer-direct", X86CPU, hyperv_features,
HYPERV_FEAT_STIMER_DIRECT, 0),
+ DEFINE_PROP_BIT64("hv-avic", X86CPU, hyperv_features,
+ HYPERV_FEAT_AVIC, 0),
DEFINE_PROP_ON_OFF_AUTO("hv-no-nonarch-coresharing", X86CPU,
hyperv_no_nonarch_cs, ON_OFF_AUTO_OFF),
DEFINE_PROP_BOOL("hv-passthrough", X86CPU, hyperv_passthrough, false),
@@ -1038,6 +1038,7 @@ typedef uint64_t FeatureWordArray[FEATURE_WORDS];
#define HYPERV_FEAT_EVMCS 12
#define HYPERV_FEAT_IPI 13
#define HYPERV_FEAT_STIMER_DIRECT 14
+#define HYPERV_FEAT_AVIC 15
#ifndef HYPERV_SPINLOCK_NEVER_NOTIFY
#define HYPERV_SPINLOCK_NEVER_NOTIFY 0xFFFFFFFF
@@ -66,6 +66,7 @@
#define HV_APIC_ACCESS_RECOMMENDED (1u << 3)
#define HV_SYSTEM_RESET_RECOMMENDED (1u << 4)
#define HV_RELAXED_TIMING_RECOMMENDED (1u << 5)
+#define HV_DEPRECATING_AEOI_RECOMMENDED (1u << 9)
#define HV_CLUSTER_IPI_RECOMMENDED (1u << 10)
#define HV_EX_PROCESSOR_MASKS_RECOMMENDED (1u << 11)
#define HV_ENLIGHTENED_VMCS_RECOMMENDED (1u << 14)
@@ -924,6 +924,13 @@ static struct {
},
.dependencies = BIT(HYPERV_FEAT_STIMER)
},
+ [HYPERV_FEAT_AVIC] = {
+ .desc = "AVIC/APICv support (hv-avic/hv-apicv)",
+ .flags = {
+ {.func = HV_CPUID_ENLIGHTMENT_INFO, .reg = R_EAX,
+ .bits = HV_DEPRECATING_AEOI_RECOMMENDED}
+ }
+ },
};
static struct kvm_cpuid2 *try_get_hv_cpuid(CPUState *cs, int max,
@@ -1373,7 +1380,8 @@ static int hyperv_fill_cpuids(CPUState *cs,
c->eax = hv_build_cpuid_leaf(cs, HV_CPUID_ENLIGHTMENT_INFO, R_EAX);
c->ebx = cpu->hyperv_spinlock_attempts;
- if (hyperv_feat_enabled(cpu, HYPERV_FEAT_VAPIC)) {
+ if (hyperv_feat_enabled(cpu, HYPERV_FEAT_VAPIC) &&
+ !hyperv_feat_enabled(cpu, HYPERV_FEAT_AVIC)) {
c->eax |= HV_APIC_ACCESS_RECOMMENDED;
}
The enlightenment allows to use Hyper-V SynIC with hardware APICv/AVIC enabled. Normally, Hyper-V SynIC disables these hardware features and suggests the guest to use paravirtualized AutoEOI feature. Linux-4.15 gains support for conditional APICv/AVIC disablement, the feature stays on until the guest tries to use AutoEOI feature with SynIC. With 'HV_DEPRECATING_AEOI_RECOMMENDED' bit exposed, modern enough Windows/ Hyper-V versions should follow the recommendation and not use the (unwanted) feature. Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com> --- docs/hyperv.txt | 10 +++++++++- target/i386/cpu.c | 4 ++++ target/i386/cpu.h | 1 + target/i386/kvm/hyperv-proto.h | 1 + target/i386/kvm/kvm.c | 10 +++++++++- 5 files changed, 24 insertions(+), 2 deletions(-)