From mboxrd@z Thu Jan 1 00:00:00 1970 From: Avi Kivity Subject: Re: [PATCH] Remove MSR_P6_{EVNTSEL0,PERFCTR0} from printk warning list. Date: Thu, 01 Jul 2010 18:02:32 +0300 Message-ID: <4C2CAE08.1050903@redhat.com> References: <1277908040-15087-1-git-send-email-Jes.Sorensen@redhat.com> <4C2CA84A.4090506@redhat.com> <4C2CA90A.6070201@redhat.com> <4C2CA9C6.60605@redhat.com> <4C2CAA8A.5010105@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Jes Sorensen Return-path: Received: from mx1.redhat.com ([209.132.183.28]:12430 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751796Ab0GAPCe (ORCPT ); Thu, 1 Jul 2010 11:02:34 -0400 Received: from int-mx04.intmail.prod.int.phx2.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.17]) by mx1.redhat.com (8.13.8/8.13.8) with ESMTP id o61F2YXE018449 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Thu, 1 Jul 2010 11:02:34 -0400 Received: from cleopatra.tlv.redhat.com (cleopatra.tlv.redhat.com [10.35.255.11]) by int-mx04.intmail.prod.int.phx2.redhat.com (8.13.8/8.13.8) with ESMTP id o61F2XEj015806 for ; Thu, 1 Jul 2010 11:02:33 -0400 In-Reply-To: <4C2CAA8A.5010105@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 07/01/2010 05:47 PM, Jes Sorensen wrote: > On 07/01/10 16:44, Avi Kivity wrote: > >> On 07/01/2010 05:41 PM, Jes Sorensen wrote: >> >>> Saw it, which is why I only suggest we remove EVNTSEL0 and PERFCTR0 but >>> not the others. If the guest is expecting normal operation it is likely >>> to use more than just the first. >>> >> Why is that? >> > Depends on usage obviously. > > >>> People are reporting these triggering in dmesg for both Linux and >>> Windows guests btw. >>> >>> We could put them so the two in question only trigger with a debug flag >>> or something like that? >>> >>> >> What values are the guests writing? Are they really expecting this >> thing to work? >> >> What would it take to emulate those counters? They're supposed to be >> relatively simple, no? >> >> > Sometimes just 0x00, other times more advanced values. I'll have to dig > into the manuals to figure out what it is: > > kvm: 9480: cpu0 unimplemented perfctr wrmsr: 0x186 data 0x130079 > kvm: 9480: cpu0 unimplemented perfctr wrmsr: 0xc1 data 0xffd7698c > kvm: 9480: cpu0 unimplemented perfctr wrmsr: 0x186 data 0x530079 > kvm: 23682: cpu0 unimplemented perfctr wrmsr: 0x186 data 0x130079 > kvm: 23682: cpu0 unimplemented perfctr wrmsr: 0xc1 data 0xffd7699c > kvm: 23682: cpu0 unimplemented perfctr wrmsr: 0x186 data 0x530079 > > I'll try and figure out what it is. > Looks like it plays with the enable bit (22). We can ignore writes that have bit 22 clear (as long as we remember the contents for a subsequent rdmsr), but we can't just ignore something that's supposed to cause the hardware to do something. -- error compiling committee.c: too many arguments to function