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 X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 305E7C67871 for ; Sat, 6 Oct 2018 18:39:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DE5AA20875 for ; Sat, 6 Oct 2018 18:39:36 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DE5AA20875 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=alien8.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728009AbeJGBn4 (ORCPT ); Sat, 6 Oct 2018 21:43:56 -0400 Received: from mail.skyhub.de ([5.9.137.197]:33938 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726364AbeJGBn4 (ORCPT ); Sat, 6 Oct 2018 21:43:56 -0400 X-Virus-Scanned: Nedap ESD1 at mail.skyhub.de Received: from mail.skyhub.de ([127.0.0.1]) by localhost (blast.alien8.de [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id VGry3GgWBVoO; Sat, 6 Oct 2018 20:39:33 +0200 (CEST) Received: from zn.tnic (p200300EC2BCA7500329C23FFFEA6A903.dip0.t-ipconnect.de [IPv6:2003:ec:2bca:7500:329c:23ff:fea6:a903]) (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 A81011EC02B2; Sat, 6 Oct 2018 20:39:33 +0200 (CEST) Date: Sat, 6 Oct 2018 20:39:28 +0200 From: Borislav Petkov To: Andi Kleen Cc: Thomas Gleixner , peterz@infradead.org, x86@kernel.org, linux-kernel@vger.kernel.org, eranian@google.com, kan.liang@intel.com, isaku.yamahata@intel.com, kvm@vger.kernel.org, Andi Kleen Subject: Re: [PATCH v1 1/2] x86/cpufeature: Add facility to match microcode revisions Message-ID: <20181006183928.GA703@zn.tnic> References: <20181006001928.28097-1-andi@firstfloor.org> <20181006181506.7cycnsg5gtoavtmx@two.firstfloor.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20181006181506.7cycnsg5gtoavtmx@two.firstfloor.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Oct 06, 2018 at 11:15:07AM -0700, Andi Kleen wrote: > The matcher can be used to match specific hardware steppings by setting > the min/max_ucode to 0 or specific microcode revisions > (which are associated with steppings) This better be explained unambiguously. > We still support the old microcode interface that allows updates > per CPU, and also it could happen during CPU hotplug. There are no per CPU microcode updates anymore - it is all or none. It is actually your microcoders who came up with a bunch of restrictions like quiescing the cores from doing *anything*, blocking hotplug, prohibiting updates if a subset of the cores is not online and still not guaranteeing it'll work all the time because . The actually very simple reason being it is just too late for microcode update when the machine is up. Where all I wanna do is rip the damn thing out completely. -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.