From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757725AbaISRWd (ORCPT ); Fri, 19 Sep 2014 13:22:33 -0400 Received: from out2-smtp.messagingengine.com ([66.111.4.26]:37136 "EHLO out2-smtp.messagingengine.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757219AbaISRWb (ORCPT ); Fri, 19 Sep 2014 13:22:31 -0400 X-Sasl-enc: 7RJSAR0VXAQPeyqvUvX9tHXrt7SMk/VpKYOhVlDGqKwB 1411147350 Date: Fri, 19 Sep 2014 14:22:18 -0300 From: Henrique de Moraes Holschuh To: Borislav Petkov Cc: Andy Lutomirski , Chuck Ebbert , "H. Peter Anvin" , "linux-kernel@vger.kernel.org" Subject: Re: x86, microcode: BUG: microcode update that changes x86_capability Message-ID: <20140919172218.GF17456@khazad-dum.debian.net> References: <541B2F33.8000002@amacapital.net> <20140918145328.0253f009@as> <9c84cde6-3d70-4337-8738-0283d06d8cf0@email.android.com> <20140918200659.GA5331@khazad-dum.debian.net> <20140919001311.GB5331@khazad-dum.debian.net> <20140919110014.GC29639@khazad-dum.debian.net> <20140919112953.GA3256@nazgul.tnic> <20140919135108.GB17456@khazad-dum.debian.net> <20140919144937.GB5318@nazgul.tnic> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140919144937.GB5318@nazgul.tnic> X-GPG-Fingerprint1: 4096R/39CB4807 C467 A717 507B BAFE D3C1 6092 0BD9 E811 39CB 4807 X-GPG-Fingerprint2: 1024D/1CDB0FE3 5422 5C61 F6B7 06FB 7E04 3738 EE25 DE3F 1CDB 0FE3 User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 19 Sep 2014, Borislav Petkov wrote: > On Fri, Sep 19, 2014 at 10:51:08AM -0300, Henrique de Moraes Holschuh wrote: > > But I will not trigger a microcode update when the intel-microcode package > > gets updated/installed anymore. The user will be warned of the need for > > either a reboot or a manually triggered microcode update. > > That's also wrong - you need to warn only on the affected machines. I could enhance iucode_tool so that it can tell you when there are pending updates. But it is a layering violation I don't like much, and it is a lot less future-proof than the stuff iucode-tool already does. I will think about it... but I'm inclined to just tell the user that "microcode updates, if any, will be applied the next time this system reboots". As for immediately updating the microcode on all processors other than Intel Haswell: this time, Felix Geyer found the issue early enough to save both Ubuntu and Debian users from harm, and I brought it to attention here as soon as I had a good idea of what was happening. But this was a close call as far as I'm concerned. Next time, we might not be so lucky. -- "One disk to rule them all, One disk to find them. One disk to bring them all and in the darkness grind them. In the Land of Redmond where the shadows lie." -- The Silicon Valley Tarot Henrique Holschuh