From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752706AbaCVAbA (ORCPT ); Fri, 21 Mar 2014 20:31:00 -0400 Received: from one.firstfloor.org ([193.170.194.197]:32897 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750789AbaCVAa5 (ORCPT ); Fri, 21 Mar 2014 20:30:57 -0400 Date: Sat, 22 Mar 2014 01:30:56 +0100 From: Andi Kleen To: "H. Peter Anvin" Cc: Andi Kleen , Peter Wu , Peter Zijlstra , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: GPF in intel_pmu_lbr_reset() with qemu -cpu host Message-ID: <20140322003056.GQ22728@two.firstfloor.org> References: <4055058.qLAukpngnj@al> <20140321192938.GJ3132@tassilo.jf.intel.com> <970fd799-8d4c-4759-8a96-1291b411f307@email.android.com> <20140321213753.GK3132@tassilo.jf.intel.com> <532CB21B.4040502@zytor.com> <8761n7nryi.fsf@tassilo.jf.intel.com> <532CB54C.8020003@zytor.com> <20140322002244.GP22728@two.firstfloor.org> <532CD8A9.5080603@zytor.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <532CD8A9.5080603@zytor.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 21, 2014 at 05:26:17PM -0700, H. Peter Anvin wrote: > On 03/21/2014 05:22 PM, Andi Kleen wrote: > >> Actually, Ingo, Borislav and I have been discussing making rdmsr_safe() > >> more of the default, especially for things like this where the error > >> handling is obvious (doesn't work? Disable the PMU.) > > > > That would be completely wrong. KVM has a full architectural perfmon PMU, > > just no model specific extensions like LBR. > > > > s/PMU/PMU extension in question/ % grep -r 'rdmsr' arch/x86/* | grep -v safe | wc -l 285 I assume it'll keep you all busy for a while. [compared to a likely one liner in KVM] -Andi