KVM: x86: simplify kvm_mwait_in_guest()

If Intel/AMD implements MWAIT, we expect that it works well and only
reject known bugs;  no reason to do it the other way around for minor
vendors.  (Not that they are relevant ATM.)

This allows further simplification of kvm_mwait_in_guest().
And use boot_cpu_has() instead of "cpu_has(&boot_cpu_data," while at it.

Reviewed-by: Alexander Graf <agraf@suse.de>
Acked-by: Borislav Petkov <bp@suse.de>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Radim Krčmář <rkrcmar@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index d15859ec5e923d86c8fdc7c920442af0fd0bb69c..c69f973111cb2614e313117d337cff8d8a030b34 100644 (file)
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -265,18 +265,8 @@ static inline u64 nsec_to_cycles(struct kvm_vcpu *vcpu, u64 nsec)
 
 static inline bool kvm_mwait_in_guest(void)
 {
-       if (!cpu_has(&boot_cpu_data, X86_FEATURE_MWAIT))
-               return false;
-
-       switch (boot_cpu_data.x86_vendor) {
-       case X86_VENDOR_AMD:
-               /* All AMD CPUs have a working MWAIT implementation */
-               return true;
-       case X86_VENDOR_INTEL:
-               return !boot_cpu_has_bug(X86_BUG_MONITOR);
-       default:
-               return false;
-       }
+       return boot_cpu_has(X86_FEATURE_MWAIT) &&
+               !boot_cpu_has_bug(X86_BUG_MONITOR);
 }
 
 #endif