From 9dd8b71091f47bac395f543779269c14d8d93c60 Mon Sep 17 00:00:00 2001 From: Tao Su Date: Thu, 6 Jul 2023 13:49:45 +0800 Subject: [PATCH] target/i386: Add support for MCDT_NO in CPUID enumeration CPUID.(EAX=7,ECX=2):EDX[bit 5] enumerates MCDT_NO. Processors enumerate this bit as 1 do not exhibit MXCSR Configuration Dependent Timing (MCDT) behavior and do not need to be mitigated to avoid data-dependent behavior for certain instructions. Since MCDT_NO is in a new sub-leaf, add a new CPUID feature word FEAT_7_2_EDX. Also update cpuid_level_func7 by FEAT_7_2_EDX. Signed-off-by: Tao Su Reviewed-by: Xiaoyao Li Message-ID: <20230706054949.66556-3-tao1.su@linux.intel.com> Signed-off-by: Paolo Bonzini --- target/i386/cpu.c | 26 ++++++++++++++++++++++++++ target/i386/cpu.h | 4 ++++ 2 files changed, 30 insertions(+) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index 952744af97..852c45b965 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -739,6 +739,7 @@ void x86_cpu_vendor_words2str(char *dst, uint32_t vendor1, #define TCG_7_1_EAX_FEATURES (CPUID_7_1_EAX_FZRM | CPUID_7_1_EAX_FSRS | \ CPUID_7_1_EAX_FSRC) #define TCG_7_1_EDX_FEATURES 0 +#define TCG_7_2_EDX_FEATURES 0 #define TCG_APM_FEATURES 0 #define TCG_6_EAX_FEATURES CPUID_6_EAX_ARAT #define TCG_XSAVE_FEATURES (CPUID_XSAVE_XSAVEOPT | CPUID_XSAVE_XGETBV1) @@ -993,6 +994,25 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = { }, .tcg_features = TCG_7_1_EDX_FEATURES, }, + [FEAT_7_2_EDX] = { + .type = CPUID_FEATURE_WORD, + .feat_names = { + NULL, NULL, NULL, NULL, + NULL, "mcdt-no", NULL, NULL, + NULL, NULL, NULL, NULL, + NULL, NULL, NULL, NULL, + NULL, NULL, NULL, NULL, + NULL, NULL, NULL, NULL, + NULL, NULL, NULL, NULL, + NULL, NULL, NULL, NULL, + }, + .cpuid = { + .eax = 7, + .needs_ecx = true, .ecx = 2, + .reg = R_EDX, + }, + .tcg_features = TCG_7_2_EDX_FEATURES, + }, [FEAT_8000_0007_EDX] = { .type = CPUID_FEATURE_WORD, .feat_names = { @@ -6017,6 +6037,11 @@ void cpu_x86_cpuid(CPUX86State *env, uint32_t index, uint32_t count, *edx = env->features[FEAT_7_1_EDX]; *ebx = 0; *ecx = 0; + } else if (count == 2) { + *edx = env->features[FEAT_7_2_EDX]; + *eax = 0; + *ebx = 0; + *ecx = 0; } else { *eax = 0; *ebx = 0; @@ -6881,6 +6906,7 @@ void x86_cpu_expand_features(X86CPU *cpu, Error **errp) x86_cpu_adjust_feat_level(cpu, FEAT_7_0_ECX); x86_cpu_adjust_feat_level(cpu, FEAT_7_1_EAX); x86_cpu_adjust_feat_level(cpu, FEAT_7_1_EDX); + x86_cpu_adjust_feat_level(cpu, FEAT_7_2_EDX); x86_cpu_adjust_feat_level(cpu, FEAT_8000_0001_EDX); x86_cpu_adjust_feat_level(cpu, FEAT_8000_0001_ECX); x86_cpu_adjust_feat_level(cpu, FEAT_8000_0007_EDX); diff --git a/target/i386/cpu.h b/target/i386/cpu.h index 2c9b0d2ebc..c196b0a482 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -628,6 +628,7 @@ typedef enum FeatureWord { FEAT_XSAVE_XSS_LO, /* CPUID[EAX=0xd,ECX=1].ECX */ FEAT_XSAVE_XSS_HI, /* CPUID[EAX=0xd,ECX=1].EDX */ FEAT_7_1_EDX, /* CPUID[EAX=7,ECX=1].EDX */ + FEAT_7_2_EDX, /* CPUID[EAX=7,ECX=2].EDX */ FEATURE_WORDS, } FeatureWord; @@ -932,6 +933,9 @@ uint64_t x86_cpu_get_supported_feature_word(FeatureWord w, /* PREFETCHIT0/1 Instructions */ #define CPUID_7_1_EDX_PREFETCHITI (1U << 14) +/* Do not exhibit MXCSR Configuration Dependent Timing (MCDT) behavior */ +#define CPUID_7_2_EDX_MCDT_NO (1U << 5) + /* XFD Extend Feature Disabled */ #define CPUID_D_1_EAX_XFD (1U << 4)