From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: memtest 4.20+ does not work with -cpu host Date: Thu, 13 Sep 2012 10:57:34 +0300 Message-ID: <20120913075734.GX20907@redhat.com> References: <5048BA0F.3070300@redhat.com> <504DC9BC.1060407@dlhnet.de> <504DCF1A.1@redhat.com> <504DD483.6050104@dlhnet.de> <504DD9F5.2040300@redhat.com> <20120910122120.GA20907@redhat.com> <504DDD37.5000804@dlhnet.de> <504DDDDA.9040001@redhat.com> <505190E5.9080008@dlhnet.de> <5051915A.2050405@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Peter Lieven , Avi Kivity , "qemu-devel@nongnu.org" , "kvm@vger.kernel.org" , "H. Peter Anvin" To: Paolo Bonzini Return-path: Received: from mx1.redhat.com ([209.132.183.28]:35185 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752146Ab2IMH5i (ORCPT ); Thu, 13 Sep 2012 03:57:38 -0400 Content-Disposition: inline In-Reply-To: <5051915A.2050405@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On Thu, Sep 13, 2012 at 09:55:06AM +0200, Paolo Bonzini wrote: > Il 13/09/2012 09:53, Peter Lieven ha scritto: > >>>> > >>> rdmsr returns it cannot read those MSRs. regardless if I use -cpu host > >>> or -cpu qemu64. > >> On the host. > >> > >> > > did you get my output? > > > > #rdmsr -0 0x194 > > 0000000000011100 > > #rdmsr -0 0xce > > 00000c0004011103 > > Yes, that can help implementing it in KVM. But without a spec to > understand what the bits actually mean, it's just as risky... > > Peter, do you have any idea where to get the spec of the memory > controller MSRs in Nehalem and newer processors? Apparently, memtest is > using them (and in particular 0x194) to find the speed of the FSB, or > something like that. > Why would anyone will want to run memtest in a vm? May be just add those MSRs to ignore list and that's it. -- Gleb.