KVM: X86: Provide a capability to disable HLT intercepts
If host CPUs are dedicated to a VM, we can avoid VM exits on HLT.
This patch adds the per-VM capability to disable them.
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Radim Krčmář <rkrcmar@redhat.com>
Cc: Jan H. Schönherr <jschoenh@amazon.de>
Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index e2d3050..82055b9 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -135,6 +135,11 @@ int kvm_update_cpuid(struct kvm_vcpu *vcpu)
return -EINVAL;
}
+ best = kvm_find_cpuid_entry(vcpu, KVM_CPUID_FEATURES, 0);
+ if (kvm_hlt_in_guest(vcpu->kvm) && best &&
+ (best->eax & (1 << KVM_FEATURE_PV_UNHALT)))
+ best->eax &= ~(1 << KVM_FEATURE_PV_UNHALT);
+
/* Update physical-address width */
vcpu->arch.maxphyaddr = cpuid_query_maxphyaddr(vcpu);
kvm_mmu_reset_context(vcpu);