Re: [Qemu-devel] cpuid problem in upstream qemu with kvm

[Dor Laor <dlaor@redhat.com>]

On 01/07/2010 01:59 PM, Avi Kivity wrote:
> On 01/07/2010 11:40 AM, Dor Laor wrote:
>>> There's no such thing as Nehalem.
>>
>>
>> Intel were ok with it. Again, you can name is corei7 or
>> xeon34234234234, I don't care, the principle remains the same.
>>
>
> There are several processors belonging to the Nehalem family and each
> have different features.

We can start with the older one, and once it get's that important add 
the newer ones.
Until that happens users can either use -host or have 
nehalem,+sse4_2,+newFeature

>
>>
>> What's not simple about the above 4 options?
>
> If a qemu/kvm/processor combo doesn't support a feature (say, nx) we
> have to remove it from the migration pool even if the Nehalem processor
> class says it's included. Or else not admit that combination into the
> migration pool in the first place.

It still management role to compute least common denominator for live 
migration sets.

btw: for nx disabled bios, we should just ignore it from product. Qemu 
direct users should add ,-nx

>
>> What's a better alternative (that insures users understand it and use
>> it and guest msi and even skype application is happy about it)?
>>
>
> Have management scan new nodes and classify them.
>

Of course. Just don't let management control stepping automatically, it 
should only be made for very advanced users and only manually.