From mboxrd@z Thu Jan  1 00:00:00 1970
From: Gleb Natapov <gleb@redhat.com>
Subject: Re: memtest 4.20+ does not work with -cpu host
Date: Thu, 13 Sep 2012 11:05:29 +0300
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Cc: Peter Lieven <pl@dlhnet.de>, Avi Kivity <avi@redhat.com>,
	"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
	"kvm@vger.kernel.org" <kvm@vger.kernel.org>,
	"H. Peter Anvin" <hpa@zytor.com>
To: Paolo Bonzini <pbonzini@redhat.com>
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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.

--
			Gleb.