From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751317Ab1JMAAs (ORCPT ); Wed, 12 Oct 2011 20:00:48 -0400 Received: from claw.goop.org ([74.207.240.146]:47011 "EHLO claw.goop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751080Ab1JMAAr (ORCPT ); Wed, 12 Oct 2011 20:00:47 -0400 Message-ID: <4E962A27.4090509@goop.org> Date: Wed, 12 Oct 2011 17:00:39 -0700 From: Jeremy Fitzhardinge User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:7.0.1) Gecko/20110930 Thunderbird/7.0.1 MIME-Version: 1.0 To: "H. Peter Anvin" CC: Borislav Petkov , Konrad Rzeszutek Wilk , the arch/x86 maintainers , Tigran Aivazian , Xen Devel , Linux Kernel Mailing List , Jeremy Fitzhardinge , Ingo Molnar , Thomas Gleixner Subject: Re: [PATCH 0/3] x86/microcode: support for microcode update in Xen dom0 References: <4E94E1E5.4070505@goop.org> <20111012101615.GA14966@aftab> <4E95D9E7.6090304@zytor.com> <4E95E7FE.6050302@goop.org> <20111012194543.GD14966@aftab> <20111012204048.GA22260@phenom.oracle.com> <4E960746.90805@zytor.com> <20111012214013.GD28723@aftab> <4E96198F.4030906@zytor.com> <4E962581.2000605@goop.org> <4E9628D4.1000605@zytor.com> In-Reply-To: <4E9628D4.1000605@zytor.com> X-Enigmail-Version: 1.3.2 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/12/2011 04:55 PM, H. Peter Anvin wrote: > On 10/12/2011 04:40 PM, Jeremy Fitzhardinge wrote: >> On 10/12/2011 03:49 PM, H. Peter Anvin wrote: >>> The stickiest part of all of this is where to leave the microcode so >>> the kernel can get to it way early. We could use the linked list, but >>> that would mean bootloader enabling; another idea was to stick it as a >>> prefix to the initramfs identified by a signature. >> >> I think it would be easiest for the multiboot case if it were a separate >> file, but I don't feel I'm really up on all the details. > > For the multiboot case, yes of course. > > Some bootloaders allow initramfs to be concatenated from multiple > files; unfortunately I'm not sure if Grub ever grew that capability. > Sigh. Presumably we'd want some way to make all possible microcode files available to the hypervisor/kernel so that there's no need to construct the bootloader config for a specific CPU vendor (or worse, CPU model). So that would need either some way of specifying multiple files, or a wrapper which can contain multiple files? J