x86: hv_evmcs CPU flag support

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 <lprosek@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Message-Id: <20181022165506.30332-3-vkuznets@redhat.com>
Reviewed-by: Roman Kagan <rkagan@virtuozzo.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Vitaly Kuznetsov 2018-10-22 18:55:06 +02:00 committed by Paolo Bonzini
parent 013aabdc66
commit e204ac612c
4 changed files with 32 additions and 2 deletions

View File

@ -5732,6 +5732,7 @@ 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),

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@ -1391,6 +1391,7 @@ struct X86CPU {
bool hyperv_frequencies;
bool hyperv_reenlightenment;
bool hyperv_tlbflush;
bool hyperv_evmcs;
bool hyperv_ipi;
bool check_cpuid;
bool enforce_cpuid;

View File

@ -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

View File

@ -869,6 +869,7 @@ 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;
@ -912,7 +913,8 @@ 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];
@ -970,7 +972,16 @@ 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++];
@ -981,6 +992,21 @@ int kvm_arch_init_vcpu(CPUState *cs)
kvm_base = KVM_CPUID_SIGNATURE_NEXT;
has_msr_hv_hypercall = true;
if (cpu->hyperv_evmcs) {
__u32 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) {