[PATCH 4/4] KVM: x86: simplify kvm_mwait_in_guest()

From: Radim KrÄmÃÅ
Date: Wed May 03 2017 - 15:39:00 EST


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().

Signed-off-by: Radim KrÄmÃÅ <rkrcmar@xxxxxxxxxx>
---
arch/x86/kvm/x86.h | 14 +++-----------
1 file changed, 3 insertions(+), 11 deletions(-)

diff --git a/arch/x86/kvm/x86.h b/arch/x86/kvm/x86.h
index 8ea4e80c24d1..b49add75ea35 100644
--- a/arch/x86/kvm/x86.h
+++ b/arch/x86/kvm/x86.h
@@ -216,17 +216,9 @@ 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:
- return !boot_cpu_has_bug(X86_BUG_AMD_E400);
- 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_AMD_E400) &&
+ !boot_cpu_has_bug(X86_BUG_MONITOR);
}

#endif
--
2.12.2