From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id CCDC53D74 for ; Mon, 21 Nov 2022 12:44:58 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id EEAB8C433D6; Mon, 21 Nov 2022 12:44:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1669034698; bh=Dz58t9g+8f6ve7iRQR+QJr9INc/CbGm6k7ibtIAQZtg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=vqjHJVmOtO1gCa9UsiVPFDMdyf61+P6oWgSMVvvXEcyQbmiTd/7MWwCq8Xq0dqZsK rLDUNd0b4KQzLPv71gcnziDrRkV6urfehb1C5ByI6d52MtSoLZI2lyFkLzU63mhMox yD4ppFSHrqDZzWsVDA0cdoWPczAbjW+Ae3lAXecc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Thomas Gleixner , Kan Liang , "Peter Zijlstra (Intel)" , Borislav Petkov , Linus Torvalds , eranian@google.com, Ingo Molnar , Suleiman Souhlal , Andi Kleen Subject: [PATCH 4.19 03/34] x86/cpufeature: Add facility to check for min microcode revisions Date: Mon, 21 Nov 2022 13:43:25 +0100 Message-Id: <20221121124151.000522553@linuxfoundation.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20221121124150.886779344@linuxfoundation.org> References: <20221121124150.886779344@linuxfoundation.org> User-Agent: quilt/0.67 Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Kan Liang 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 Signed-off-by: Suleiman Souhlal Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/cpu_device_id.h | 28 ++++++++++++++++++++++++++++ arch/x86/kernel/cpu/match.c | 31 +++++++++++++++++++++++++++++++ 2 files changed, 59 insertions(+) --- 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 --- 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(c 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);