From mboxrd@z Thu Jan 1 00:00:00 1970 From: "H. Peter Anvin" Subject: Re: [RFC] CPUID usage for interaction between Hypervisors and Linux. Date: Wed, 01 Oct 2008 10:45:55 -0700 Message-ID: <48E3B753.7000309@zytor.com> References: <1222881242.9381.17.camel@alok-dev1> <48E3B19D.6060905@zytor.com> <1222882431.9381.23.camel@alok-dev1> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit 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" To: akataria@vmware.com Return-path: Received: from terminus.zytor.com ([198.137.202.10]:35564 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752502AbYJARts (ORCPT ); Wed, 1 Oct 2008 13:49:48 -0400 In-Reply-To: <1222882431.9381.23.camel@alok-dev1> Sender: kvm-owner@vger.kernel.org List-ID: Alok Kataria wrote: > > 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). > It doesn't matter, really; it's still the wrong thing to do, for the same reason it's the wrong thing in -- for example -- ACPI, which has similar "cleverness". If we want to have a "Linux standard CPUID interface" suite we should just put them on a different set of numbers and let a hypervisor export all the interfaces. -hpa