From dfd5b456108a75588ab094358ba5754787146d3d Mon Sep 17 00:00:00 2001 From: Babu Moger Date: Thu, 8 May 2025 14:58:02 -0500 Subject: [PATCH] target/i386: Add couple of feature bits in CPUID_Fn80000021_EAX Add CPUID bit indicates that a WRMSR to MSR_FS_BASE, MSR_GS_BASE, or MSR_KERNEL_GS_BASE is non-serializing amd PREFETCHI that the indicates support for IC prefetch. CPUID_Fn80000021_EAX Bit Feature description 20 Indicates support for IC prefetch. 1 FsGsKernelGsBaseNonSerializing. WRMSR to FS_BASE, GS_BASE and KernelGSbase are non-serializing. Link: https://www.amd.com/content/dam/amd/en/documents/epyc-technical-docs/programmer-references/57238.zip Signed-off-by: Babu Moger Reviewed-by: Maksim Davydov Reviewed-by: Zhao Liu Link: https://lore.kernel.org/r/a5f6283a59579b09ac345b3f21ecb3b3b2d92451.1746734284.git.babu.moger@amd.com Signed-off-by: Paolo Bonzini --- target/i386/cpu.c | 4 ++-- target/i386/cpu.h | 4 ++++ 2 files changed, 6 insertions(+), 2 deletions(-) diff --git a/target/i386/cpu.c b/target/i386/cpu.c index d01a808e3a..0d1b907778 100644 --- a/target/i386/cpu.c +++ b/target/i386/cpu.c @@ -1253,12 +1253,12 @@ FeatureWordInfo feature_word_info[FEATURE_WORDS] = { [FEAT_8000_0021_EAX] = { .type = CPUID_FEATURE_WORD, .feat_names = { - "no-nested-data-bp", NULL, "lfence-always-serializing", NULL, + "no-nested-data-bp", "fs-gs-base-ns", "lfence-always-serializing", NULL, NULL, NULL, "null-sel-clr-base", NULL, "auto-ibrs", NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, NULL, - NULL, NULL, NULL, NULL, + "prefetchi", NULL, NULL, NULL, "eraps", NULL, NULL, "sbpb", "ibpb-brtype", "srso-no", "srso-user-kernel-no", NULL, }, diff --git a/target/i386/cpu.h b/target/i386/cpu.h index 22e82444ae..1146465c8c 100644 --- a/target/i386/cpu.h +++ b/target/i386/cpu.h @@ -1092,12 +1092,16 @@ uint64_t x86_cpu_get_supported_feature_word(X86CPU *cpu, FeatureWord w); /* Processor ignores nested data breakpoints */ #define CPUID_8000_0021_EAX_NO_NESTED_DATA_BP (1U << 0) +/* WRMSR to FS_BASE, GS_BASE, or KERNEL_GS_BASE is non-serializing */ +#define CPUID_8000_0021_EAX_FS_GS_BASE_NS (1U << 1) /* LFENCE is always serializing */ #define CPUID_8000_0021_EAX_LFENCE_ALWAYS_SERIALIZING (1U << 2) /* Null Selector Clears Base */ #define CPUID_8000_0021_EAX_NULL_SEL_CLR_BASE (1U << 6) /* Automatic IBRS */ #define CPUID_8000_0021_EAX_AUTO_IBRS (1U << 8) +/* Indicates support for IC prefetch */ +#define CPUID_8000_0021_EAX_PREFETCHI (1U << 20) /* Enhanced Return Address Predictor Scurity */ #define CPUID_8000_0021_EAX_ERAPS (1U << 24) /* Selective Branch Predictor Barrier */ -- 2.39.5