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Diffstat (limited to 'arch/x86/kvm/cpuid.h')
-rw-r--r--arch/x86/kvm/cpuid.h9
1 files changed, 8 insertions, 1 deletions
diff --git a/arch/x86/kvm/cpuid.h b/arch/x86/kvm/cpuid.h
index 67d80aa72d50..d2884162a46a 100644
--- a/arch/x86/kvm/cpuid.h
+++ b/arch/x86/kvm/cpuid.h
@@ -11,7 +11,6 @@ extern u32 kvm_cpu_caps[NR_KVM_CPU_CAPS] __read_mostly;
void kvm_set_cpu_caps(void);
void kvm_vcpu_after_set_cpuid(struct kvm_vcpu *vcpu);
-void kvm_update_cpuid_runtime(struct kvm_vcpu *vcpu);
struct kvm_cpuid_entry2 *kvm_find_cpuid_entry_index(struct kvm_vcpu *vcpu,
u32 function, u32 index);
struct kvm_cpuid_entry2 *kvm_find_cpuid_entry(struct kvm_vcpu *vcpu,
@@ -232,6 +231,14 @@ static __always_inline bool guest_cpu_cap_has(struct kvm_vcpu *vcpu,
{
unsigned int x86_leaf = __feature_leaf(x86_feature);
+ /*
+ * Except for MWAIT, querying dynamic feature bits is disallowed, so
+ * that KVM can defer runtime updates until the next CPUID emulation.
+ */
+ BUILD_BUG_ON(x86_feature == X86_FEATURE_APIC ||
+ x86_feature == X86_FEATURE_OSXSAVE ||
+ x86_feature == X86_FEATURE_OSPKE);
+
return vcpu->arch.cpu_caps[x86_leaf] & __feature_bit(x86_feature);
}