From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756400Ab3AHTsV (ORCPT ); Tue, 8 Jan 2013 14:48:21 -0500 Received: from terminus.zytor.com ([198.137.202.10]:37054 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753843Ab3AHTsU (ORCPT ); Tue, 8 Jan 2013 14:48:20 -0500 Message-ID: <50EC77DB.6090300@zytor.com> Date: Tue, 08 Jan 2013 11:47:39 -0800 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: Konrad Rzeszutek Wilk CC: Fenghua Yu , Ingo Molnar , Thomas Gleixner , Asit K Mallick , Tigran Aivazian , Yinghai Lu , Andreas Herrmann , Borislav Petkov , linux-kernel , x86 Subject: Re: [PATCH v5 00/12] x86/microcode: Early load microcode References: <1356075872-3054-1-git-send-email-fenghua.yu@intel.com> <20130103174455.GA7350@localhost.localdomain> <50E5C47B.6060707@zytor.com> <20130108194633.GA15194@phenom.dumpdata.com> In-Reply-To: <20130108194633.GA15194@phenom.dumpdata.com> X-Enigmail-Version: 1.4.6 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 01/08/2013 11:46 AM, Konrad Rzeszutek Wilk wrote: > > OK. I am trying to figure out whether this usage of native_* for the > MSRs was done on purpose - and it sounds like the answer is no. If so - > can it be done using the normal 'safe_rdmsr' and 'wrmsr'? > > That would allow at least in the case of Xen, to omit a whole bunch > of MSR writes/reads during the boot that are not neccessary as we would > not trap in the hypervisor - but could use the pvops version of > read/write MSR calls to just do a nop. > Why is this code invoked on Xen at all? That seems crazy. -hpa