Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753827AbYJAReE (ORCPT ); Wed, 1 Oct 2008 13:34:04 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752386AbYJARdw (ORCPT ); Wed, 1 Oct 2008 13:33:52 -0400 Received: from smtp-outbound-1.vmware.com ([65.113.40.141]:59774 "EHLO smtp-outbound-1.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752087AbYJARdw (ORCPT ); Wed, 1 Oct 2008 13:33:52 -0400 Subject: Re: [RFC] CPUID usage for interaction between Hypervisors and Linux. From: Alok Kataria Reply-To: akataria@vmware.com To: "H. Peter Anvin" Cc: Jeremy Fitzhardinge , "avi@redhat.com" , Rusty Russell , Gerd Hoffmann , Ingo Molnar , the arch/x86 maintainers , LKML , "Nakajima, Jun" , Daniel Hecht , Zach Amsden , "virtualization@lists.linux-foundation.org" , "kvm@vger.kernel.org" In-Reply-To: <48E3B19D.6060905@zytor.com> References: <1222881242.9381.17.camel@alok-dev1> <48E3B19D.6060905@zytor.com> Content-Type: text/plain Organization: VMware INC. Date: Wed, 01 Oct 2008 10:33:51 -0700 Message-Id: <1222882431.9381.23.camel@alok-dev1> Mime-Version: 1.0 X-Mailer: Evolution 2.8.0 (2.8.0-40.el5_1.1) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1117 Lines: 31 On Wed, 2008-10-01 at 10:21 -0700, H. Peter Anvin wrote: > Alok Kataria wrote: > > > > (This proposal may be adopted by other guest OSes. However, that is not > > a requirement because a hypervisor can expose a different CPUID > > interface depending on the guest OS type that is specified by the VM > > configuration.) > > > > Excuse me, but that is blatantly idiotic. Expecting the user having to > configure a VM to match the target OS is *exactly* as stupid as > expecting the user to reconfigure the BIOS. It's totally the wrong > thing to do. Hi Peter, Its not a user who has to do anything special here. There are *intelligent* VM developers out there who can export a different CPUid interface depending on the guest OS type. And this is what most of the hypervisors do (not necessarily for CPUID, but for other things right now). Alok. > > -hpa -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/