From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx4+PQCF2vGHk4810KcLDtVNWxX99Y8oZYapGf+btKQSLzUzuyVNemTmBO58Eb5zirEbuqW1o ARC-Seal: i=1; a=rsa-sha256; t=1524240019; cv=none; d=google.com; s=arc-20160816; b=kj4TRROQLr87fFmsZFWmJSpmCo5oS5+HY9uesDD/v4WDz2NFixtdghTDsVyY/zGz7w 7NevgQTb/KprSq+T2tdgOh5so9RbnwsCb5jrbRAQbWGozvLvziRuRFsbYw/dyeLexVi9 iwPio1VSHgxIb1yBnlPWphmI2YJNEUsveVo9m47BHLQWemoJCOd0xFd13EBvGfdM119O AUywxp3EY42cu5wBujvse4XyGr9CkCKyyJjJysRNDsxTki/wyVphVU8pLXeNjLTKs/Jz +Vm1aPBuyutEw8I7g6jN5gO9equQJWiRilDRmYB2uDNZyxkymJ80eBSlQENBnquv3r2o ishA== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:arc-authentication-results; bh=Y3rfnBCnnoiAZkzs6iRjbfvcQjz2eRvuqnFTtVINiyw=; b=h2SUtLtEWJzeMLcGObXcDkyQn880oF3DCkRBstAXt/UqRBML6OfwoTURXkgFJ3lqN1 xTEVAAxbTMVD9rEii1SPRUpxbJ+B6dnyKKdt4iq7J5WG5NnnS/0Cax6ZbkRWvvhuVM0d 7vvtVU9rA91+6oXcXdLu7lkd6udYimHOgcEsA4Kwk/rBCrRdIIxOnaOZ9JwKJTcqTkNi Mz9C2rJlC1uwwfAmWVOVBulnl7Iqd1Uaeh/VsyRSutCiPXAEd/EO5lpSJxSa9gh1OAwD T5OSTe5z4Ug0J9cE/nqKdbekKdX4ixxoQGBuZbTOQW8XlROwxJEjN1CgsrweZEggDrNS v+7g== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: domain of ashok.raj@intel.com designates 134.134.136.65 as permitted sender) smtp.mailfrom=ashok.raj@intel.com Authentication-Results: mx.google.com; spf=pass (google.com: domain of ashok.raj@intel.com designates 134.134.136.65 as permitted sender) smtp.mailfrom=ashok.raj@intel.com X-Amp-Result: UNSCANNABLE X-Amp-File-Uploaded: False X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,302,1520924400"; d="scan'208";a="193082415" Date: Fri, 20 Apr 2018 09:00:18 -0700 From: "Raj, Ashok" To: Borislav Petkov Cc: Vitezslav Samel , Greg Kroah-Hartman , linux-kernel@vger.kernel.org, x86-ml Subject: Re: [PATCH 2/2] x86/microcode: Do not exit early from __reload_late() Message-ID: <20180420160017.GB9792@araj-mobl1.jf.intel.com> References: <20180419104829.GE3896@pd.tnic> <20180419120239.GA2377@pc11.op.pod.cz> <20180419121840.GF3896@pd.tnic> <20180419134627.GA2387@pc11.op.pod.cz> <20180419163734.GB3905@pd.tnic> <20180420062021.GA2253@pc11.op.pod.cz> <20180420095220.GA13977@pd.tnic> <20180420100131.GA14217@pc11.op.pod.cz> <20180420103242.GB13977@pd.tnic> <20180420103708.GE13977@pd.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180420103708.GE13977@pd.tnic> User-Agent: Mutt/1.9.1 (2017-09-22) X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-THRID: =?utf-8?q?1598261173668216348?= X-GMAIL-MSGID: =?utf-8?q?1598281502508960208?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: On Fri, Apr 20, 2018 at 12:37:08PM +0200, Borislav Petkov wrote: > Vitezslav reported a case where the > > "Timeout during microcode update!" > > panic would hit. After a deeper look, it turned out that his .config had > CONFIG_HOTPLUG_CPU disabled which practically made save_mc_for_early() a > no-op. > > When that happened, the discovered microcode patch wasn't saved into our > cache and the late loading path wouldn't find any. > > This, then, lead to early exit from __reload_late() and thus CPUs > waiting until the timeout is reached, leading to the panic. > > In hindsight, I should've made that function not return before the > post-synchronization. Oh well, I know better now... > > Reported-by: Vitezslav Samel > Signed-off-by: Borislav Petkov Tested-by: Ashok Raj > Cc: Ashok Raj > Cc: > Fixes: bb8c13d61a62 ("x86/microcode: Fix CPU synchronization routine") > Link: http://lkml.kernel.org/r/20180418081140.GA2439@pc11.op.pod.cz > ---