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 A29C4C4332F for ; Fri, 2 Dec 2022 19:02:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234574AbiLBTCK (ORCPT ); Fri, 2 Dec 2022 14:02:10 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53962 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234788AbiLBTB5 (ORCPT ); Fri, 2 Dec 2022 14:01:57 -0500 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5B24FE2545 for ; Fri, 2 Dec 2022 11:01:56 -0800 (PST) From: Thomas Gleixner DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1670007715; 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: in-reply-to:in-reply-to:references:references; bh=hGD3C2OE9Qr7B30PrUOZTVQpnPl/hR6oT6hCymS6mLQ=; b=cP1lR3J1+7x602QMu+R7Zmq6JJQ/tCP7vavRb9MLflK0KE3oiouqHqwrYM5cDQ3bZG0XAw u4iWqFXeDpQSZ02r0Qz6y8HmKPPz5vQcmSZcTK5YcDE032gG1Klw3EP9v1v7HI65pGTwP+ 3wR2w2zREpD7Ok9VQ8cYcLEChgTZmR/H5It/SMc4f6Fc1W0LfEZ65Hn6jQaL8WIEMbMPpB 7pySlj018ZY4tRuTBXroGx/fdc2K1JiBUPAUQt9Mje9iC1mfE4Oz263H3Hg9FHGB8Ar8wN XkNTZzbfcW56ZHRIKcxQsJUldvz3RMntI6ReMvWd8ihuJfnxvQOSA4cSWelfVA== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1670007715; 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: in-reply-to:in-reply-to:references:references; bh=hGD3C2OE9Qr7B30PrUOZTVQpnPl/hR6oT6hCymS6mLQ=; b=Fi5AU0bx2GJoGywQ/bKSnMtAADSdLFyl+TCsQN27Sc3jeLFZ50FsDuWQ4HrZbEQdFHzKmV aM0+nih/s5akZwAg== To: Ashok Raj , Borislav Petkov Cc: X86-kernel , LKML Mailing List , Ashok Raj , Dave Hansen , Tony Luck , alison.schofield@intel.com, reinette.chatre@intel.com Subject: Re: [Patch V1 2/7] x86/microcode/intel: Remove retries on early microcode load In-Reply-To: <20221129210832.107850-3-ashok.raj@intel.com> References: <20221129210832.107850-1-ashok.raj@intel.com> <20221129210832.107850-3-ashok.raj@intel.com> Date: Fri, 02 Dec 2022 20:01:54 +0100 Message-ID: <87a645pr31.ffs@tglx> MIME-Version: 1.0 Content-Type: text/plain Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Nov 29 2022 at 13:08, Ashok Raj wrote: > Microcode loading can fail. This happens today when handling mixed > steppings. But it can also happen for other reasons such as corrupted > image, Security Version Number (SVN) preventing anti-rollback, > dependencies on BIOS loaded microcode image for some capabilities. > > When the microcode loading fails, the kernel will quietly hang at boot. > This has been observed by end users (Links below) who had to revert their > microcode packages in order to boot again. > > The hang is due to an infinite retry loop. The retries were in place to > support systems with mixed steppings. Now that mixed steppings are no > longer supported, there is only one microcode image at a time. Any retries > will simply reattempt to apply the same image over and over without making > progress. > > Some possible past bugs that could be due to this bug are below. > > There is no direct evidence that these end user issues were caused by this > retry loop. However, the early boot hangs along with reverting the > microcode update workaround provide strong circumstantial evidence to > support the theory that they are linked. > > Remove the retry loop and only attempt to apply microcode once. Very concise and informative changelog. See, you can do it :) > Link: https://bugs.launchpad.net/ubuntu/+source/intel-microcode/+bug/1911959 > Link: https://forums.linuxmint.com/viewtopic.php?p=1827032#1827032 > Link: https://askubuntu.com/questions/1291486/boot-crash-after-latest-update-of-intel-microcode-nov-11-2020 > Fixes: 06b8534cb728 ("x86/microcode: Rework microcode loading") > Cc: stable@vger.kernel.org > Signed-off-by: Ashok Raj Nit: Can you order the tags according to the tip documentation next time please? Reviewed-by: Thomas Gleixner