From: Vitaly Kuznetsov <vkuzn...@redhat.com>
Adds a new CPU flag to enable the Enlightened VMCS KVM feature.
QEMU enables KVM_CAP_HYPERV_ENLIGHTENED_VMCS and gets back the
version to be advertised in lower 16 bits of CPUID.0x4000000A:EAX.
Suggested-by: Ladi Prosek <lpro...@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuzn...@redhat.com>
Message-Id: <20181022165506.30332-3-vkuzn...@redhat.com>
Reviewed-by: Roman Kagan <rka...@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
---
target/i386/cpu.c | 1 +
target/i386/cpu.h | 1 +
target/i386/hyperv-proto.h | 2 ++
target/i386/kvm.c | 30 ++++++++++++++++++++++++++++--
4 files changed, 32 insertions(+), 2 deletions(-)
diff --git a/target/i386/cpu.c b/target/i386/cpu.c
index 1469a1b..e74b986 100644
--- a/target/i386/cpu.c
+++ b/target/i386/cpu.c
@@ -5565,6 +5565,7 @@ static Property x86_cpu_properties[] = {
DEFINE_PROP_BOOL("hv-frequencies", X86CPU, hyperv_frequencies, false),
DEFINE_PROP_BOOL("hv-reenlightenment", X86CPU, hyperv_reenlightenment,
false),
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("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 663f3a5..369c223 100644
--- a/target/i386/cpu.h
+++ b/target/i386/cpu.h
@@ -1383,6 +1383,7 @@ struct X86CPU {
bool hyperv_frequencies;
bool hyperv_reenlightenment;
bool hyperv_tlbflush;
+ bool hyperv_evmcs;
bool hyperv_ipi;
bool check_cpuid;
bool enforce_cpuid;
diff --git a/target/i386/hyperv-proto.h b/target/i386/hyperv-proto.h
index 8c572cd..c0272b3 100644
--- a/target/i386/hyperv-proto.h
+++ b/target/i386/hyperv-proto.h
@@ -18,6 +18,7 @@
#define HV_CPUID_FEATURES 0x40000003
#define HV_CPUID_ENLIGHTMENT_INFO 0x40000004
#define HV_CPUID_IMPLEMENT_LIMITS 0x40000005
+#define HV_CPUID_NESTED_FEATURES 0x4000000A
#define HV_CPUID_MIN 0x40000005
#define HV_CPUID_MAX 0x4000ffff
#define HV_HYPERVISOR_PRESENT_BIT 0x80000000
@@ -60,6 +61,7 @@
#define HV_RELAXED_TIMING_RECOMMENDED (1u << 5)
#define HV_CLUSTER_IPI_RECOMMENDED (1u << 10)
#define HV_EX_PROCESSOR_MASKS_RECOMMENDED (1u << 11)
+#define HV_ENLIGHTENED_VMCS_RECOMMENDED (1u << 14)
/*
* Basic virtualized MSRs
diff --git a/target/i386/kvm.c b/target/i386/kvm.c
index 115d8b4..6f5c8a0 100644
--- a/target/i386/kvm.c
+++ b/target/i386/kvm.c
@@ -832,6 +832,7 @@ int kvm_arch_init_vcpu(CPUState *cs)
uint32_t unused;
struct kvm_cpuid_entry2 *c;
uint32_t signature[3];
+ uint16_t evmcs_version;
int kvm_base = KVM_CPUID_SIGNATURE;
int r;
Error *local_err = NULL;
@@ -875,7 +876,8 @@ int kvm_arch_init_vcpu(CPUState *cs)
memset(signature, 0, 12);
memcpy(signature, cpu->hyperv_vendor_id, len);
}
- c->eax = HV_CPUID_MIN;
+ c->eax = cpu->hyperv_evmcs ?
+ HV_CPUID_NESTED_FEATURES : HV_CPUID_IMPLEMENT_LIMITS;
c->ebx = signature[0];
c->ecx = signature[1];
c->edx = signature[2];
@@ -933,7 +935,16 @@ int kvm_arch_init_vcpu(CPUState *cs)
c->eax |= HV_CLUSTER_IPI_RECOMMENDED;
c->eax |= HV_EX_PROCESSOR_MASKS_RECOMMENDED;
}
-
+ if (cpu->hyperv_evmcs) {
+ if (kvm_vcpu_enable_cap(cs, KVM_CAP_HYPERV_ENLIGHTENED_VMCS, 0,
+ (uintptr_t)&evmcs_version)) {
+ fprintf(stderr, "Hyper-V Enlightened VMCS "
+ "(requested by 'hv-evmcs' cpu flag) "
+ "is not supported by kernel\n");
+ return -ENOSYS;
+ }
+ c->eax |= HV_ENLIGHTENED_VMCS_RECOMMENDED;
+ }
c->ebx = cpu->hyperv_spinlock_attempts;
c = &cpuid_data.entries[cpuid_i++];
@@ -944,6 +955,21 @@ int kvm_arch_init_vcpu(CPUState *cs)
kvm_base = KVM_CPUID_SIGNATURE_NEXT;
has_msr_hv_hypercall = true;
+
+ if (cpu->hyperv_evmcs) {
+ uint32_t function;
+
+ /* Create zeroed 0x40000006..0x40000009 leaves */
+ for (function = HV_CPUID_IMPLEMENT_LIMITS + 1;
+ function < HV_CPUID_NESTED_FEATURES; function++) {
+ c = &cpuid_data.entries[cpuid_i++];
+ c->function = function;
+ }
+
+ c = &cpuid_data.entries[cpuid_i++];
+ c->function = HV_CPUID_NESTED_FEATURES;
+ c->eax = evmcs_version;
+ }
}
if (cpu->expose_kvm) {
--
1.8.3.1
