From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D6ED4C4332F for ; Wed, 4 Jan 2023 18:57:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239347AbjADS5D (ORCPT ); Wed, 4 Jan 2023 13:57:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:52522 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231392AbjADS5A (ORCPT ); Wed, 4 Jan 2023 13:57:00 -0500 Received: from mail.skyhub.de (mail.skyhub.de [5.9.137.197]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3296B13DFA for ; Wed, 4 Jan 2023 10:56:58 -0800 (PST) Received: from zn.tnic (p5de8e9fe.dip0.t-ipconnect.de [93.232.233.254]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.skyhub.de (SuperMail on ZX Spectrum 128k) with ESMTPSA id 0F8D71EC02FE; Wed, 4 Jan 2023 19:56:57 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1672858617; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:in-reply-to:in-reply-to: references:references; bh=eI6hrybg3gLaj8bRbb/kt2kToyODb7dNUhJzp/ZLGpY=; b=l9gQ/gxHxlA9XtFIgW4MXMZ1vjMsP+AdznrIPuUUkXphaUE1LhTpk4529b/7ZShKtpo6Ud v6V33oRywy0qwExgp4lfdnI52CzmXNWY2jSYaq800QemysqMc3sZs5dBUC47WLIbPQ1bN5 Lv+GPYpEe13qujigxQIsY3Uq1GyNDl4= Date: Wed, 4 Jan 2023 19:56:52 +0100 From: Borislav Petkov To: Ashok Raj Cc: Thomas Gleixner , X86-kernel , LKML Mailing List , Dave Hansen , Tony Luck , Alison Schofield , Reinette Chatre , Tom Lendacky Subject: Re: [PATCH v3 2/6] x86/microcode/core: Take a snapshot before and after applying microcode Message-ID: References: <20230103180212.333496-1-ashok.raj@intel.com> <20230103180212.333496-3-ashok.raj@intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20230103180212.333496-3-ashok.raj@intel.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jan 03, 2023 at 10:02:08AM -0800, Ashok Raj wrote: > Fixes: 1008c52c09dc ("x86/CPU: Add a microcode loader callback") Why a Fixes tag? Do you have a failure scenario for current kernels? If so, then it would need stable backporting. If so, it would need the previous patch too. > diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h > index 387578049de0..ac2e67156b9b 100644 > --- a/arch/x86/include/asm/processor.h > +++ b/arch/x86/include/asm/processor.h > @@ -697,6 +697,7 @@ bool xen_set_default_idle(void); > #endif > > void __noreturn stop_this_cpu(void *dummy); > +void microcode_store_cpu_caps(struct cpuinfo_x86 *info); s/microcode_store_cpu_caps/store_cpu_caps/g > void microcode_check(struct cpuinfo_x86 *info); > > enum l1tf_mitigations { > diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c > index b9c7529c920e..7c86c6fd07ae 100644 > --- a/arch/x86/kernel/cpu/common.c > +++ b/arch/x86/kernel/cpu/common.c > @@ -2297,28 +2297,43 @@ void cpu_init_secondary(void) > #endif > > #ifdef CONFIG_MICROCODE_LATE_LOADING > + > +void microcode_store_cpu_caps(struct cpuinfo_x86 *info) > +{ > + /* Reload CPUID max function as it might've changed. */ Might've changed how? > + info->cpuid_level = cpuid_eax(0); > + > + /* > + * Copy all capability leafs to pick up the synthetic ones so that > + * memcmp() below doesn't fail on that... split that comment and put the second part... > + */ > + memcpy(info->x86_capability, &boot_cpu_data.x86_capability, > + sizeof(info->x86_capability)); > + ... here: /* * ... the ones coming from CPUID will get overwritten here: */ > + get_cpu_cap(info); > +} > + > /* > * The microcode loader calls this upon late microcode load to recheck features, > * only when microcode has been updated. Caller holds microcode_mutex and CPU > * hotplug lock. > */ > -void microcode_check(struct cpuinfo_x86 *info) > +void microcode_check(struct cpuinfo_x86 *orig) ^^^^^ Yeah, what dhansen said. Thx. -- Regards/Gruss, Boris. https://people.kernel.org/tglx/notes-about-netiquette