KVM: X86: Provide a capability to disable MWAIT intercepts

Allowing a guest to execute MWAIT without interception enables a guest
to put a (physical) CPU into a power saving state, where it takes
longer to return from than what may be desired by the host.

Don't give a guest that power over a host by default. (Especially,
since nothing prevents a guest from using MWAIT even when it is not
advertised via CPUID.)

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>

1 files changed, 1 insertions, 1 deletions

diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index fa1c4977e1c2..f6578cee6bb6 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1398,7 +1398,7 @@ static void init_vmcb(struct vcpu_svm *svm)
         set_intercept(svm, INTERCEPT_XSETBV);
         set_intercept(svm, INTERCEPT_RSM);
 
-        if (!kvm_mwait_in_guest()) {
+        if (!kvm_mwait_in_guest(svm->vcpu.kvm)) {
                 set_intercept(svm, INTERCEPT_MONITOR);
                 set_intercept(svm, INTERCEPT_MWAIT);
         }