diff mbox series

[v13,06/35] x86/cpufeatures: Add the CPU feature bit for FRED

Message ID 20231205105030.8698-7-xin3.li@intel.com (mailing list archive)
State New, archived
Headers show
Series x86: enable FRED for x86-64 | expand

Commit Message

Li, Xin3 Dec. 5, 2023, 10:49 a.m. UTC 
From: "H. Peter Anvin (Intel)" <hpa@zytor.com>

Any FRED CPU will always have the following features as its baseline:
  1) LKGS, load attributes of the GS segment but the base address into
     the IA32_KERNEL_GS_BASE MSR instead of the GS segment’s descriptor
     cache.
  2) WRMSRNS, non-serializing WRMSR for faster MSR writes.

Signed-off-by: H. Peter Anvin (Intel) <hpa@zytor.com>
Tested-by: Shan Kang <shan.kang@intel.com>
Signed-off-by: Xin Li <xin3.li@intel.com>
---

Change since v12:
* s/cpu/CPU/g (Borislav Petkov).
---
 arch/x86/include/asm/cpufeatures.h       | 1 +
 arch/x86/kernel/cpu/cpuid-deps.c         | 2 ++
 tools/arch/x86/include/asm/cpufeatures.h | 1 +
 3 files changed, 4 insertions(+)
diff mbox series

Patch

diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h
index a903fc130e49..fef95d190054 100644
--- a/arch/x86/include/asm/cpufeatures.h
+++ b/arch/x86/include/asm/cpufeatures.h
@@ -324,6 +324,7 @@ 
 #define X86_FEATURE_FZRM		(12*32+10) /* "" Fast zero-length REP MOVSB */
 #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_FRED		(12*32+17) /* Flexible Return and Event Delivery */
 #define X86_FEATURE_LKGS		(12*32+18) /* "" Load "kernel" (userspace) GS */
 #define X86_FEATURE_WRMSRNS		(12*32+19) /* "" Non-serializing WRMSR */
 #define X86_FEATURE_AMX_FP16		(12*32+21) /* "" AMX fp16 Support */
diff --git a/arch/x86/kernel/cpu/cpuid-deps.c b/arch/x86/kernel/cpu/cpuid-deps.c
index e462c1d3800a..b7174209d855 100644
--- a/arch/x86/kernel/cpu/cpuid-deps.c
+++ b/arch/x86/kernel/cpu/cpuid-deps.c
@@ -82,6 +82,8 @@  static const struct cpuid_dep cpuid_deps[] = {
 	{ X86_FEATURE_XFD,			X86_FEATURE_XGETBV1   },
 	{ X86_FEATURE_AMX_TILE,			X86_FEATURE_XFD       },
 	{ X86_FEATURE_SHSTK,			X86_FEATURE_XSAVES    },
+	{ X86_FEATURE_FRED,			X86_FEATURE_LKGS      },
+	{ X86_FEATURE_FRED,			X86_FEATURE_WRMSRNS   },
 	{}
 };
 
diff --git a/tools/arch/x86/include/asm/cpufeatures.h b/tools/arch/x86/include/asm/cpufeatures.h
index 26a73ae18a86..f433e9f61354 100644
--- a/tools/arch/x86/include/asm/cpufeatures.h
+++ b/tools/arch/x86/include/asm/cpufeatures.h
@@ -321,6 +321,7 @@ 
 #define X86_FEATURE_FZRM		(12*32+10) /* "" Fast zero-length REP MOVSB */
 #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_FRED		(12*32+17) /* Flexible Return and Event Delivery */
 #define X86_FEATURE_LKGS		(12*32+18) /* "" Load "kernel" (userspace) GS */
 #define X86_FEATURE_WRMSRNS		(12*32+19) /* "" Non-serializing WRMSR */
 #define X86_FEATURE_AMX_FP16		(12*32+21) /* "" AMX fp16 Support */