x86/kvm: Don't use PV TLB/yield when mwait is advertised

MWAIT is advertised in host is not overcommitted scenario, however, PV
TLB/sched yield should be enabled in host overcommitted scenario. Let's
add the MWAIT checking when enabling PV TLB/sched yield.

Signed-off-by: Wanpeng Li <wanpengli@tencent.com>
Message-Id: <1645777780-2581-1-git-send-email-wanpengli@tencent.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

diff --git a/arch/x86/kernel/kvm.c b/arch/x86/kernel/kvm.c
index f734e3b0cfecbd4c9176742a518ddf1832e13d6a..491e1d9ca7504916fa5f040ae3c327059dbbb152 100644 (file)
--- a/arch/x86/kernel/kvm.c
+++ b/arch/x86/kernel/kvm.c
@@ -463,6 +463,7 @@ static bool pv_tlb_flush_supported(void)
        return (kvm_para_has_feature(KVM_FEATURE_PV_TLB_FLUSH) &&
                !kvm_para_has_hint(KVM_HINTS_REALTIME) &&
                kvm_para_has_feature(KVM_FEATURE_STEAL_TIME) &&
+               !boot_cpu_has(X86_FEATURE_MWAIT) &&
                (num_possible_cpus() != 1));
 }
 
@@ -477,6 +478,7 @@ static bool pv_sched_yield_supported(void)
        return (kvm_para_has_feature(KVM_FEATURE_PV_SCHED_YIELD) &&
                !kvm_para_has_hint(KVM_HINTS_REALTIME) &&
            kvm_para_has_feature(KVM_FEATURE_STEAL_TIME) &&
+           !boot_cpu_has(X86_FEATURE_MWAIT) &&
            (num_possible_cpus() != 1));
 }