From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754327Ab1BBVsH (ORCPT ); Wed, 2 Feb 2011 16:48:07 -0500 Received: from terminus.zytor.com ([198.137.202.10]:34841 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753291Ab1BBVsG (ORCPT ); Wed, 2 Feb 2011 16:48:06 -0500 Message-ID: <4D49D0E6.30102@zytor.com> Date: Wed, 02 Feb 2011 13:47:18 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20101209 Fedora/3.1.7-0.35.b3pre.fc13 Thunderbird/3.1.7 MIME-Version: 1.0 To: Borislav Petkov , Jeremy Fitzhardinge , Ingo Molnar , the arch/x86 maintainers , Linux Kernel Mailing List , Xen Devel , Jeremy Fitzhardinge Subject: Re: [PATCH 0/2] x86/microcode: support for microcode update in Xen dom0 References: <20110130113356.GA27967@liondog.tnic> <4D461FB9.5050807@goop.org> <20110131070241.GA22071@liondog.tnic> <4D46FC9F.6090309@goop.org> <20110131234131.GA16095@liondog.tnic> <4D475099.1080004@goop.org> <4D475DB5.1020300@zytor.com> <4D488EB1.9020803@goop.org> <4D49B5F6.5010606@zytor.com> <20110202205704.GA14752@liondog.tnic> In-Reply-To: <20110202205704.GA14752@liondog.tnic> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 02/02/2011 12:57 PM, Borislav Petkov wrote: > On Wed, Feb 02, 2011 at 11:52:22AM -0800, H. Peter Anvin wrote: >> 3. Arguably on native hardware we should still load the microcode into >> RAM in the boot loader, and install it on the very early CPU bringup >> path. That means locking down some (currently) 400K of RAM to handle >> different combinations of CPUs, or the additional complexity of >> jettisoning microcode which cannot be used while still be able to deal >> with hotplug. I think there is a strong case for this model, which >> would mean moving the microcode into /boot anyway. > > /me like it, sounds very nifty. So how do we want to do that, we add > a field to the real-mode kernel header that tells us where to find > the microcode image and we take it and apply the ucode somewhere in > do_boot_cpu() path? > We already have a mechanism for passing arbitrary blobs -- the linked list -- so we don't have to add a new field at all. -hpa From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [PATCH 0/2] x86/microcode: support for microcode update in Xen dom0 Date: Wed, 02 Feb 2011 13:47:18 -0800 Message-ID: <4D49D0E6.30102@zytor.com> References: <20110130113356.GA27967@liondog.tnic> <4D461FB9.5050807@goop.org> <20110131070241.GA22071@liondog.tnic> <4D46FC9F.6090309@goop.org> <20110131234131.GA16095@liondog.tnic> <4D475099.1080004@goop.org> <4D475DB5.1020300@zytor.com> <4D488EB1.9020803@goop.org> <4D49B5F6.5010606@zytor.com> <20110202205704.GA14752@liondog.tnic> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20110202205704.GA14752@liondog.tnic> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: Borislav Petkov , Jeremy Fitzhardinge , Ingo Molnar , the arch/x86 maintainers , Linux Kernel Mailing List List-Id: xen-devel@lists.xenproject.org On 02/02/2011 12:57 PM, Borislav Petkov wrote: > On Wed, Feb 02, 2011 at 11:52:22AM -0800, H. Peter Anvin wrote: >> 3. Arguably on native hardware we should still load the microcode into >> RAM in the boot loader, and install it on the very early CPU bringup >> path. That means locking down some (currently) 400K of RAM to handle >> different combinations of CPUs, or the additional complexity of >> jettisoning microcode which cannot be used while still be able to deal >> with hotplug. I think there is a strong case for this model, which >> would mean moving the microcode into /boot anyway. > > /me like it, sounds very nifty. So how do we want to do that, we add > a field to the real-mode kernel header that tells us where to find > the microcode image and we take it and apply the ucode somewhere in > do_boot_cpu() path? > We already have a mechanism for passing arbitrary blobs -- the linked list -- so we don't have to add a new field at all. -hpa