Re: memtest 4.20+ does not work with -cpu host

[Peter Lieven <pl@dlhnet.de>]

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.