diff mbox series

[v6,11/33] KVM: x86: hyper-v: Cache HYPERV_CPUID_NESTED_FEATURES CPUID leaf

Message ID 20220830133737.1539624-12-vkuznets@redhat.com (mailing list archive)
State New, archived
Headers show
Series KVM: VMX: Support updated eVMCSv1 revision + use vmcs_config for L1 VMX MSRs | expand

Commit Message

Vitaly Kuznetsov Aug. 30, 2022, 1:37 p.m. UTC 
KVM has to check guest visible HYPERV_CPUID_NESTED_FEATURES.EBX CPUID
leaf to know which Enlightened VMCS definition to use (original or 2022
update). Cache the leaf along with other Hyper-V CPUID feature leaves
to make the check quick.

Reviewed-by: Maxim Levitsky <mlevitsk@redhat.com>
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
---
 arch/x86/include/asm/kvm_host.h | 2 ++
 arch/x86/kvm/hyperv.c           | 6 ++++++
 2 files changed, 8 insertions(+)
diff mbox series

Patch

diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 2c96c43c313a..9411348e4223 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -615,6 +615,8 @@  struct kvm_vcpu_hv {
 		u32 enlightenments_eax; /* HYPERV_CPUID_ENLIGHTMENT_INFO.EAX */
 		u32 enlightenments_ebx; /* HYPERV_CPUID_ENLIGHTMENT_INFO.EBX */
 		u32 syndbg_cap_eax; /* HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES.EAX */
+		u32 nested_eax; /* HYPERV_CPUID_NESTED_FEATURES.EAX */
+		u32 nested_ebx; /* HYPERV_CPUID_NESTED_FEATURES.EBX */
 	} cpuid_cache;
 };
 
diff --git a/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index bf4729e8cc80..a7478b61088b 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -2018,6 +2018,12 @@  void kvm_hv_set_cpuid(struct kvm_vcpu *vcpu, bool hyperv_enabled)
 	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_SYNDBG_PLATFORM_CAPABILITIES);
 	if (entry)
 		hv_vcpu->cpuid_cache.syndbg_cap_eax = entry->eax;
+
+	entry = kvm_find_cpuid_entry(vcpu, HYPERV_CPUID_NESTED_FEATURES);
+	if (entry) {
+		hv_vcpu->cpuid_cache.nested_eax = entry->eax;
+		hv_vcpu->cpuid_cache.nested_ebx = entry->ebx;
+	}
 }
 
 int kvm_hv_set_enforce_cpuid(struct kvm_vcpu *vcpu, bool enforce)