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=-5.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 49927C4360F for ; Fri, 5 Apr 2019 04:20:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0DDD02175B for ; Fri, 5 Apr 2019 04:20:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=alien8.de header.i=@alien8.de header.b="RLEt3tif" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726356AbfDEEKi (ORCPT ); Fri, 5 Apr 2019 00:10:38 -0400 Received: from mail.skyhub.de ([5.9.137.197]:46520 "EHLO mail.skyhub.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725967AbfDEEKi (ORCPT ); Fri, 5 Apr 2019 00:10:38 -0400 Received: from zn.tnic (p200300EC2F148A00329C23FFFEA6A903.dip0.t-ipconnect.de [IPv6:2003:ec:2f14:8a00:329c: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 33D4F1EC02D1; Fri, 5 Apr 2019 06:10:36 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=alien8.de; s=dkim; t=1554437436; 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=wxV47DWj4vLfQ/1haMoePUR6PTgYz/3r3M4PHZsUk6Y=; b=RLEt3tifIh1ufADAjDahDdMyhXogVpRbzHMNVkVBCX/yKGJYtFgwt69W4sQtqDk5mLxj8N lJ10prTLzIIg4RHJWXcdNP/Tu+27xlhs/PSVJwCjAhQTk8yQuZU8TCKQHD+MGh3qV5d400 npuvdFClGtca9TTdxW6o++t7WCEjdm0= Date: Fri, 5 Apr 2019 06:10:28 +0200 From: Borislav Petkov To: Jann Horn Cc: Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , the arch/x86 maintainers , kernel list , David Laight Subject: Re: [PATCH] x86/microcode: Refactor Intel microcode loading Message-ID: <20190405041028.GA23348@zn.tnic> References: <20190404111128.131157-1-jannh@google.com> <20190404162753.GG22539@zn.tnic> <20190404164741.GH22539@zn.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: 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 Fri, Apr 05, 2019 at 12:54:31AM +0200, Jann Horn wrote: > [ 159.485731] microcode: CPU7 found a matching microcode update with > version 0x25 (current=0x19) Yeah, that printk can be kinda misleading :) > I thought I had checked /sys/devices/system/cpu/cpu0/microcode/version > afterwards. But apparently I didn't. Bleh. Sorry about that. No worries at all, now at least it is all clear what's happening. I was beginning to recheck what I'm seeing here too. And I can finally deprecate this ancient method which is just as kaputtski because it is happening as late as the late loading method when you do echo 1 > /sys/devices/system/cpu/microcode/reload --- diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index 5ad92419be19..5a0a752f3ddd 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -1330,8 +1330,16 @@ config MICROCODE_AMD processors will be enabled. config MICROCODE_OLD_INTERFACE - def_bool y + bool "Ancient loading interface (DEPRECATED)" + default n depends on MICROCODE + ---help--- + DO NOT USE THIS! This is the ancient /dev/cpu/microcode interface + which was used by userspace tools like iucode_tool and microcode.ctl. + It is inadequate because it runs too late to be able to properly + load microcode on a machine and it needs special tools. Instead, you + should've switched to the early loading method with the initrd or + builtin microcode by now: Documentation/x86/microcode.txt config X86_MSR tristate "/dev/cpu/*/msr - Model-specific register support" --- I'll test some more and post later. Thx! -- Regards/Gruss, Boris. Good mailing practices for 400: avoid top-posting and trim the reply.