diff mbox series

[v3,20/27] KVM: x86: Allow WRMSRNS to be advertised to guests

Message ID 20241001050110.3643764-21-xin@zytor.com (mailing list archive)
State New, archived
Headers show
Series Enable FRED with KVM VMX | expand

Commit Message

Xin Li Oct. 1, 2024, 5:01 a.m. UTC 
From: Xin Li <xin3.li@intel.com>

Allow WRMSRNS to be advertised to guests.

WRMSRNS behaves exactly like WRMSR with the only difference being
that it is not a serializing instruction by default.  It improves
performance when being used in a hot path, e.g., setting FRED RSP0.

Signed-off-by: Xin Li <xin3.li@intel.com>
Signed-off-by: Xin Li (Intel) <xin@zytor.com>
Tested-by: Shan Kang <shan.kang@intel.com>
---
 arch/x86/kvm/cpuid.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/x86/kvm/cpuid.c b/arch/x86/kvm/cpuid.c
index c55d150ece8d..63a78ebf9482 100644
--- a/arch/x86/kvm/cpuid.c
+++ b/arch/x86/kvm/cpuid.c
@@ -700,7 +700,7 @@  void kvm_set_cpu_caps(void)
 	kvm_cpu_cap_mask(CPUID_7_1_EAX,
 		F(AVX_VNNI) | F(AVX512_BF16) | F(CMPCCXADD) |
 		F(FZRM) | F(FSRS) | F(FSRC) | F(FRED) | F(LKGS) |
-		F(AMX_FP16) | F(AVX_IFMA) | F(LAM)
+		F(WRMSRNS) | F(AMX_FP16) | F(AVX_IFMA) | F(LAM)
 	);
 
 	kvm_cpu_cap_init_kvm_defined(CPUID_7_1_EDX,