From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Lieven Subject: Re: memtest 4.20+ does not work with -cpu host Date: Thu, 13 Sep 2012 14:05:23 +0200 Message-ID: <5051CC03.1030101@dlhnet.de> References: <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> <20120913075734.GX20907@redhat.com> <5051929A.2060407@redhat.com> <20120913080529.GY20907@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: Paolo Bonzini , Avi Kivity , "qemu-devel@nongnu.org" , "kvm@vger.kernel.org" , "H. Peter Anvin" To: Gleb Natapov Return-path: Received: from ssl.dlhnet.de ([91.198.192.8]:58308 "EHLO ssl.dlh.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757699Ab2IMMFZ (ORCPT ); Thu, 13 Sep 2012 08:05:25 -0400 In-Reply-To: <20120913080529.GY20907@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: On 13.09.2012 10:05, Gleb Natapov wrote: > On Thu, Sep 13, 2012 at 10:00:26AM +0200, Paolo Bonzini wrote: >> Il 13/09/2012 09:57, Gleb Natapov ha scritto: >>>>>>> #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. >> >From the output it looks like it's basically a list of bits. Returning >> something sensible is better, same as for the speed scaling MSRs. >> > Everything is list of bits in computers :) At least 0xce is documented in SDM. > It cannot be implemented in a migration safe manner. What do you suggest just say memtest does not work? I am wondering why it is working with -cpu qemu64. Peter > > -- > Gleb.