From mboxrd@z Thu Jan 1 00:00:00 1970 From: Zachary Amsden Subject: Re: KVM PMU virtualization Date: Mon, 01 Mar 2010 09:03:49 -1000 Message-ID: <4B8C0F95.1090400@redhat.com> References: <4B86917C.4070102@redhat.com> <20100225173423.GB4246@8bytes.org> <20100226084241.GF15885@elte.hu> <4B87987A.2020302@redhat.com> <20100226104437.GB7463@elte.hu> <4B87AF44.9090702@redhat.com> <20100226114217.GI7463@elte.hu> <4B87B5DE.30503@redhat.com> <20100226120750.GA11578@elte.hu> <4B87BC74.7050207@redhat.com> <20100226133149.GA23422@elte.hu> <4B87CE93.1070906@redhat.com> <4B87D2EA.1090503@redhat.com> <1267194420.22519.605.camel@laptop> <4B87E09C.3080209@redhat.com> <1267196885.22519.643.camel@laptop> <4B87E4B6.2070009@redhat.com> <1267199748.22519.725.camel@laptop> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: Avi Kivity , Jes Sorensen , Ingo Molnar , Joerg Roedel , KVM General , Gleb Natapov , ming.m.lin@intel.com, "Zhang, Yanmin" , Thomas Gleixner , "H. Peter Anvin" , Arjan van de Ven , Fr??d??ric Weisbecker , Arnaldo Carvalho de Melo To: Peter Zijlstra Return-path: Received: from mx1.redhat.com ([209.132.183.28]:50780 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751522Ab0CATEf (ORCPT ); Mon, 1 Mar 2010 14:04:35 -0500 In-Reply-To: <1267199748.22519.725.camel@laptop> Sender: kvm-owner@vger.kernel.org List-ID: On 02/26/2010 05:55 AM, Peter Zijlstra wrote: > On Fri, 2010-02-26 at 17:11 +0200, Avi Kivity wrote: > >> On 02/26/2010 05:08 PM, Peter Zijlstra wrote: >> >>>> That's 7 more than what we support now, and 7 more than what we can >>>> guarantee without it. >>>> >>>> >>> Again, what windows software uses only those 7? Does it pay to only have >>> access to those 7 or does it limit the usability to exactly the same >>> subset a paravirt interface would? >>> >>> >> Good question. Would be interesting to try out VTune with the non-arch >> pmu masked out. >> > Also, the ANY bit is part of the intel arch pmu, but you still have to > mask it out. > > BTW, just wondering, why would a developer be running VTune in a guest > anyway? I'd think that a developer that windows oriented would simply > run windows on his desktop and VTune there. > What if you want to run on 10 different variations of Windows 32 / 64 / server / desktop configurations. Do you maintain 10 installed pieces of hardware? A virtual machine is a better solution. And you might want to performance tune all 10 of those configurations as well. Be nice if it were possible.