From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753747Ab2GXKKq (ORCPT ); Tue, 24 Jul 2012 06:10:46 -0400 Received: from osrc3.amd.com ([217.9.48.20]:57773 "EHLO mail.x86-64.org" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1753611Ab2GXKKp (ORCPT ); Tue, 24 Jul 2012 06:10:45 -0400 Date: Tue, 24 Jul 2012 12:10:41 +0200 From: Borislav Petkov To: Vladimir Davydov Cc: Andre Przywara , Thomas Gleixner , Ingo Molnar , "H. Peter Anvin" , Andi Kleen , Borislav Petkov , "x86@kernel.org" , "linux-kernel@vger.kernel.org" , Andreas Herrmann Subject: Re: [PATCH 2/2] cpu: intel, amd: mask cleared cpuid features Message-ID: <20120724101041.GA24739@aftab.osrc.amd.com> References: <73e09fb43e37de851acda10dc64bc495a5b68357.1342801662.git.vdavydov@parallels.com> <20120721103715.GA3632@aftab.osrc.amd.com> <500E4960.8040307@parallels.com> <500E5951.5020900@amd.com> <500E5CDF.5000504@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <500E5CDF.5000504@parallels.com> 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 Tue, Jul 24, 2012 at 12:29:19PM +0400, Vladimir Davydov wrote: > I guess that when the more advanced features become widely-used, > vendors will offer new MSRs and/or CPUID faulting. And this right there is the dealbreaker: So what are you doing for cpus which have the advanced CPUID features leafs but there are no MSRs to turn those bits off? You surely need some software-only solution for the migration to work, no? If so, why not apply that solution to your hypervisor without touching the kernel at all? Thanks. -- Regards/Gruss, Boris. Advanced Micro Devices GmbH Einsteinring 24, 85609 Dornach GM: Alberto Bozzo Reg: Dornach, Landkreis Muenchen HRB Nr. 43632 WEEE Registernr: 129 19551