KVM on Via Nano (Isaiah) CPUs?

KVM on Via Nano (Isaiah) CPUs?

[Craig Metz]

  Has anyone (esp. the KVM core developers) tried to determine whether KVM
works on the new Via Nano CPUs? They claim to support the Intel-style VT-x
instruction set extensions and show up in cpuinfo that way. But, according to
some Google searching, folks who have tried to use KVM (or Hyper-V) have not
been succesful. It's not clear if this is a CPU implementation problem and/or
something that needs more work in KVM.

  Has anyone tried this / debugged this?

  Thanks,

																	-Craig

Re: KVM on Via Nano (Isaiah) CPUs?

[Avi Kivity]

Craig Metz wrote:
>   Has anyone (esp. the KVM core developers) tried to determine whether KVM
> works on the new Via Nano CPUs? They claim to support the Intel-style VT-x
> instruction set extensions and show up in cpuinfo that way. But, according to
> some Google searching, folks who have tried to use KVM (or Hyper-V) have not
> been succesful. It's not clear if this is a CPU implementation problem and/or
> something that needs more work in KVM.
>   

Via engineers have contacted me and confirmed that this is a problem in 
the processor.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

Re: KVM on Via Nano (Isaiah) CPUs?

[Craig Metz]

In message <49D396AB.6090304@redhat.com>, you write:
>Via engineers have contacted me and confirmed that this is a problem in 
>the processor.

  Is there a known-fixed CPU revision?

  Is there a way to identify working vs. non-working chips, either from IC
stamp or from /proc/cpuinfo? (Bonus: is it possible to put a check and an error
into the kvm-intel kernel model?)

  Thanks,

																		-Craig

Re: KVM on Via Nano (Isaiah) CPUs?

[Avi Kivity]

Craig Metz wrote:
> In message <49D396AB.6090304@redhat.com>, you write:
>   
>> Via engineers have contacted me and confirmed that this is a problem in 
>> the processor.
>>     
>
>   Is there a known-fixed CPU revision?
>
>   Is there a way to identify working vs. non-working chips, either from IC
> stamp or from /proc/cpuinfo? (Bonus: is it possible to put a check and an error
> into the kvm-intel kernel model?)
>   

I have no idea.  Please contact Via for this information.

-- 
I have a truly marvellous patch that fixes the bug which this
signature is too narrow to contain.

Re: KVM on Via Nano (Isaiah) CPUs? <Virus checked>

[Andreas Tanz]

> Craig Metz wrote:
> > In message <49D396AB.6090304@redhat.com>, you write:
> >   
> >> Via engineers have contacted me and confirmed that this is a problem in 
> >> the processor.
> >>     
> >
> >   Is there a known-fixed CPU revision?
> >
> >   Is there a way to identify working vs. non-working chips, either from IC
> > stamp or from /proc/cpuinfo? (Bonus: is it possible to put a check and an error
> > into the kvm-intel kernel model?)
> >   
> 
> I have no idea.  Please contact Via for this information.
> 

Hi,

I've read an EMail from VIA, telling that the Nano must be at least stepping 3.
Prior steppings have a buggy vt implementation...
(Damn! I have stepping 2 :-I )

Re: KVM on Via Nano (Isaiah) CPUs? <Virus checked>

[Avi Kivity]

Andreas Tanz wrote:
>> Craig Metz wrote:
>>     
>>> In message <49D396AB.6090304@redhat.com>, you write:
>>>   
>>>       
>>>> Via engineers have contacted me and confirmed that this is a problem in 
>>>> the processor.
>>>>     
>>>>         
>>>   Is there a known-fixed CPU revision?
>>>
>>>   Is there a way to identify working vs. non-working chips, either from IC
>>> stamp or from /proc/cpuinfo? (Bonus: is it possible to put a check and an error
>>> into the kvm-intel kernel model?)
>>>   
>>>       
>> I have no idea.  Please contact Via for this information.
>>
>>     
>
> Hi,
>
> I've read an EMail from VIA, telling that the Nano must be at least stepping 3.
> Prior steppings have a buggy vt implementation...
> (Damn! I have stepping 2 :-I )
>   

Can you send your /proc/cpuinfo, I'll try to blacklist it.


-- 
Do not meddle in the internals of kernels, for they are subtle and quick to panic.

Re: KVM on Via Nano (Isaiah) CPUs?

[Oliver Rath]

Hi Jesse!

Jesse Ahrens schrieb:
> > Via engineers have contacted me and confirmed that this is a problem in
> > the processor.
>
> I'd like to clarify. Stepping 2 Nano processors do not support VMX.
> This should have been disabled by the BIOS. Support for VMX was not
> finished until stepping 3. If you have a stepping 2 processor with
> this enabled please let me know which platform it is on so we can have
> the manufacturer release a new BIOS.


What is the actual Stepping for Via Nano Processors? Is VT running fine
since stepping 3?

Regards

Oliver

Re: KVM on Via Nano (Isaiah) CPUs?

[Jesse Ahrens]

 > Via engineers have contacted me and confirmed that this is a problem in
 > the processor.

I'd like to clarify. Stepping 2 Nano processors do not support VMX. This 
should have been disabled by the BIOS. Support for VMX was not finished 
until stepping 3. If you have a stepping 2 processor with this enabled 
please let me know which platform it is on so we can have the 
manufacturer release a new BIOS.

Jesse Ahrens
Systems Engineer
Centaur Technology