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[PATCH v11 01/37] x86/cpufeatures: Add the cpu feature bit for WRMSRNS

From: Xin Li <hidden>
Date: 2023-09-23 10:11:48
Also in: kvm, linux-edac, linux-hyperv, lkml, xen-devel
Subsystem: the rest, x86 architecture (32-bit and 64-bit) · Maintainers: Linus Torvalds, Thomas Gleixner, Ingo Molnar, Borislav Petkov, Dave Hansen

WRMSRNS is an instruction that behaves exactly like WRMSR, with
the only difference being that it is not a serializing instruction
by default. Under certain conditions, WRMSRNS may replace WRMSR to
improve performance.

Add the CPU feature bit for WRMSRNS.

Tested-by: Shan Kang <redacted>
Signed-off-by: Xin Li <redacted>
---
 arch/x86/include/asm/cpufeatures.h       | 1 +
 tools/arch/x86/include/asm/cpufeatures.h | 1 +
 2 files changed, 2 insertions(+)
diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index 58cb9495e40f..330876d34b68 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -322,6 +322,7 @@
 #define X86_FEATURE_FSRS		(12*32+11) /* "" Fast short REP STOSB */
 #define X86_FEATURE_FSRC		(12*32+12) /* "" Fast short REP {CMPSB,SCASB} */
 #define X86_FEATURE_LKGS		(12*32+18) /* "" Load "kernel" (userspace) GS */
+#define X86_FEATURE_WRMSRNS		(12*32+19) /* "" Non-Serializing Write to Model Specific Register instruction */
 #define X86_FEATURE_AMX_FP16		(12*32+21) /* "" AMX fp16 Support */
 #define X86_FEATURE_AVX_IFMA            (12*32+23) /* "" Support for VPMADD52[H,L]UQ */
 #define X86_FEATURE_LAM			(12*32+26) /* Linear Address Masking */
diff --git a/tools/arch/x86/include/asm/cpufeatures.h b/tools/arch/x86/include/asm/cpufeatures.h
index 798e60b5454b..1b9d86ba5bc2 100644
--- a/tools/arch/x86/include/asm/cpufeatures.h
+++ b/tools/arch/x86/include/asm/cpufeatures.h
@@ -318,6 +318,7 @@
 #define X86_FEATURE_FSRS		(12*32+11) /* "" Fast short REP STOSB */
 #define X86_FEATURE_FSRC		(12*32+12) /* "" Fast short REP {CMPSB,SCASB} */
 #define X86_FEATURE_LKGS		(12*32+18) /* "" Load "kernel" (userspace) GS */
+#define X86_FEATURE_WRMSRNS		(12*32+19) /* "" Non-Serializing Write to Model Specific Register instruction */
 #define X86_FEATURE_AMX_FP16		(12*32+21) /* "" AMX fp16 Support */
 #define X86_FEATURE_AVX_IFMA            (12*32+23) /* "" Support for VPMADD52[H,L]UQ */
 #define X86_FEATURE_LAM			(12*32+26) /* Linear Address Masking */
-- 
2.34.1
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