From: H. Peter Anvin (Intel) Date: Tue, 5 Dec 2023 10:49:55 +0000 (-0800) Subject: x86/cpufeatures: Add the CPU feature bit for FRED X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=51c158f7aaccc6f6423a61a1df4a0d4c0d9d22a9;p=linux.git x86/cpufeatures: Add the CPU feature bit for FRED Any FRED enabled 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) Signed-off-by: Xin Li Signed-off-by: Thomas Gleixner Tested-by: Shan Kang Link: https://lore.kernel.org/r/20231205105030.8698-7-xin3.li@intel.com --- diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h index bd05c75c62aa2..ccbf914b3d1a3 100644 --- a/arch/x86/include/asm/cpufeatures.h +++ b/arch/x86/include/asm/cpufeatures.h @@ -326,6 +326,7 @@ #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 e462c1d3800a6..b7174209d855c 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 8792841016031..953e6efead265 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 */