From 0237199186e7a4aa5310741f0a6498a20c820fd7 Mon Sep 17 00:00:00 2001 From: Jiaxun Yang Date: Tue, 20 Nov 2018 11:00:18 +0800 Subject: [PATCH 1/2] x86/CPU/AMD: Set the CPB bit unconditionally on F17h Some F17h models do not have CPB set in CPUID even though the CPU supports it. Set the feature bit unconditionally on all F17h. [ bp: Rewrite commit message and patch. ] Signed-off-by: Jiaxun Yang Signed-off-by: Borislav Petkov Acked-by: Tom Lendacky Cc: "H. Peter Anvin" Cc: Ingo Molnar Cc: Sherry Hurwitz Cc: Suravee Suthikulpanit Cc: Thomas Gleixner Cc: x86-ml Link: https://lkml.kernel.org/r/20181120030018.5185-1-jiaxun.yang@flygoat.com --- arch/x86/kernel/cpu/amd.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/cpu/amd.c b/arch/x86/kernel/cpu/amd.c index 69f6bbb41be0..01004bfb1a1b 100644 --- a/arch/x86/kernel/cpu/amd.c +++ b/arch/x86/kernel/cpu/amd.c @@ -819,11 +819,9 @@ static void init_amd_bd(struct cpuinfo_x86 *c) static void init_amd_zn(struct cpuinfo_x86 *c) { set_cpu_cap(c, X86_FEATURE_ZEN); - /* - * Fix erratum 1076: CPB feature bit not being set in CPUID. It affects - * all up to and including B1. - */ - if (c->x86_model <= 1 && c->x86_stepping <= 1) + + /* Fix erratum 1076: CPB feature bit not being set in CPUID. */ + if (!cpu_has(c, X86_FEATURE_CPB)) set_cpu_cap(c, X86_FEATURE_CPB); } From 0f42b790c9ba5ec2f25b7da8b0b6d361082d67b0 Mon Sep 17 00:00:00 2001 From: Kan Liang Date: Mon, 4 Feb 2019 14:23:29 -0800 Subject: [PATCH 2/2] x86/cpufeature: Add facility to check for min microcode revisions For bug workarounds or checks, it is useful to check for specific microcode revisions. Add a new generic function to match the CPU with stepping. Add the other function to check the min microcode revisions for the matched CPU. A new table format is introduced to facilitate the quirk to fill the related information. This does not change the existing x86_cpu_id because it's an ABI shared with modules, and also has quite different requirements, as in no wildcards, but everything has to be matched exactly. Originally-by: Andi Kleen Suggested-by: Thomas Gleixner Signed-off-by: Kan Liang Signed-off-by: Peter Zijlstra (Intel) Acked-by: Borislav Petkov Cc: Linus Torvalds Cc: Peter Zijlstra Cc: eranian@google.com Link: https://lkml.kernel.org/r/1549319013-4522-1-git-send-email-kan.liang@linux.intel.com Signed-off-by: Ingo Molnar --- arch/x86/include/asm/cpu_device_id.h | 28 +++++++++++++++++++++++++ arch/x86/kernel/cpu/match.c | 31 ++++++++++++++++++++++++++++ 2 files changed, 59 insertions(+) diff --git a/arch/x86/include/asm/cpu_device_id.h b/arch/x86/include/asm/cpu_device_id.h index baeba0567126..3417110574c1 100644 --- a/arch/x86/include/asm/cpu_device_id.h +++ b/arch/x86/include/asm/cpu_device_id.h @@ -11,4 +11,32 @@ extern const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match); +/* + * Match specific microcode revisions. + * + * vendor/family/model/stepping must be all set. + * + * Only checks against the boot CPU. When mixed-stepping configs are + * valid for a CPU model, add a quirk for every valid stepping and + * do the fine-tuning in the quirk handler. + */ + +struct x86_cpu_desc { + __u8 x86_family; + __u8 x86_vendor; + __u8 x86_model; + __u8 x86_stepping; + __u32 x86_microcode_rev; +}; + +#define INTEL_CPU_DESC(mod, step, rev) { \ + .x86_family = 6, \ + .x86_vendor = X86_VENDOR_INTEL, \ + .x86_model = mod, \ + .x86_stepping = step, \ + .x86_microcode_rev = rev, \ +} + +extern bool x86_cpu_has_min_microcode_rev(const struct x86_cpu_desc *table); + #endif diff --git a/arch/x86/kernel/cpu/match.c b/arch/x86/kernel/cpu/match.c index 3fed38812eea..6dd78d8235e4 100644 --- a/arch/x86/kernel/cpu/match.c +++ b/arch/x86/kernel/cpu/match.c @@ -48,3 +48,34 @@ const struct x86_cpu_id *x86_match_cpu(const struct x86_cpu_id *match) return NULL; } EXPORT_SYMBOL(x86_match_cpu); + +static const struct x86_cpu_desc * +x86_match_cpu_with_stepping(const struct x86_cpu_desc *match) +{ + struct cpuinfo_x86 *c = &boot_cpu_data; + const struct x86_cpu_desc *m; + + for (m = match; m->x86_family | m->x86_model; m++) { + if (c->x86_vendor != m->x86_vendor) + continue; + if (c->x86 != m->x86_family) + continue; + if (c->x86_model != m->x86_model) + continue; + if (c->x86_stepping != m->x86_stepping) + continue; + return m; + } + return NULL; +} + +bool x86_cpu_has_min_microcode_rev(const struct x86_cpu_desc *table) +{ + const struct x86_cpu_desc *res = x86_match_cpu_with_stepping(table); + + if (!res || res->x86_microcode_rev > boot_cpu_data.microcode) + return false; + + return true; +} +EXPORT_SYMBOL_GPL(x86_cpu_has_min_microcode_rev);