From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: perf uncore & lkvm woes Date: Thu, 16 Aug 2012 11:40:22 +0300 Message-ID: <502CB1F6.4010204@redhat.com> References: <1345101585.31459.112.camel@twins> <502CA368.8050404@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: "Yan, Zheng" , Peter Zijlstra , Sasha Levin , Asias He , Cyrill Gorcunov , Ingo Molnar , KVM General To: Pekka Enberg Return-path: Received: from mx1.redhat.com ([209.132.183.28]:21546 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756558Ab2HPIkg (ORCPT ); Thu, 16 Aug 2012 04:40:36 -0400 In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: On 08/16/2012 10:41 AM, Pekka Enberg wrote: > On 08/16/2012 03:19 PM, Peter Zijlstra wrote: >>> On Thu, 2012-08-16 at 10:01 +0300, Pekka Enberg wrote: >>>> Has anyone seen this? It's kvmtool/next with 3.6.0-rc1. Looks like we >>>> are doing uncore_init() on virtualized CPU which breaks boot. >>> >>> I think you're the first.. I don't normally use kvm if I can at all >>> avoid it. >>> >>> But I think its a 'simple' matter of kvm not emulating the entire >>> hardware. Afaik the uncore isn't enumerated and we simply assume MSR >>> presence based on cpu model. > > On Thu, Aug 16, 2012 at 10:38 AM, Yan, Zheng > wrote: >> The Intel uncore doc does not specify how to check if uncore exist. >> How about disabling uncore on virtualized CPU? > > (CC'ing Avi.) > Seems reasonable, if unfortunate. It's pretty easy to check for. If those are separate MSRs, we can also trap the #GP and exit gracefully. -- error compiling committee.c: too many arguments to function