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

[Xin Li <xin3.li@xxxxxxxxx>]

From: "H. Peter Anvin (Intel)" <hpa@xxxxxxxxx>

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@xxxxxxxxx>
Tested-by: Shan Kang <shan.kang@xxxxxxxxx>
Signed-off-by: Xin Li <xin3.li@xxxxxxxxx>
---

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 --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 */
-- 
2.43.0