From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: nmi is broken? Date: Tue, 03 May 2011 17:37:17 +0300 Message-ID: <4DC0131D.5090407@redhat.com> References: <87sjtbe7fz.fsf@devron.myhome.or.jp> <877hak1t1s.fsf@devron.myhome.or.jp> <4DB3C6D3.9040703@redhat.com> <4DB42EC3.3090002@web.de> <4DBFCE25.2060603@redhat.com> <4DBFDAE1.3030104@siemens.com> <4DC003BF.9060204@redhat.com> <4DC0114B.3080907@siemens.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: OGAWA Hirofumi , "kvm@vger.kernel.org" To: Jan Kiszka Return-path: Received: from mx1.redhat.com ([209.132.183.28]:3428 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751073Ab1ECOhZ (ORCPT ); Tue, 3 May 2011 10:37:25 -0400 In-Reply-To: <4DC0114B.3080907@siemens.com> Sender: kvm-owner@vger.kernel.org List-ID: On 05/03/2011 05:29 PM, Jan Kiszka wrote: > On 2011-05-03 15:31, Avi Kivity wrote: > > On 05/03/2011 01:37 PM, Jan Kiszka wrote: > >>> > >>> Yes. Unfortunately that is very vendor and model specific. The > >>> architectural PMU is supported, but that is only available on Intel. > >> > >> Is it supposed to have any practical value already? I did not yet find a > >> magic -cpu switch to let Linux detect anything, not to speak of perf or > >> watchdog support. > > > > On the guest side it is supported for the watchdog > > (arch/x86/kernel/cpu/perfctr-watchdog.c, look for > > X86_FEATURE_ARCH_PERFMON). It's also mentioned in perf_event_intel.c, > > but I don't know if it will work without the other PMU features being > > present. > > I've tested with some SUSE 2.6.38 guest kernel, and it complained like > this: > > (-cpu kvm64) > Performance Events: unsupported Netburst CPU model 6 no PMU driver, software events only. > NMI watchdog disabled (cpu0): hardware events not enabled > Sorry, I meant to write, but forgot, that on the host side it is completely unsupported. It shouldn't be too hard to use perf_events to emulate the architectural PMU. Once we do that we can expose the architectural pmu bit and the guest will use it. -- error compiling committee.c: too many arguments to function