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

[Paolo Bonzini <pbonzini@redhat.com>]

>> No, Windows tries to detect changes in your hardware and assumes that
>> if too many things change, you might be a pirate and requires you to
>> phone their offices to re-authenticate.
>
> 'Just' the CPU is not big deal. Might hit you with two 'bad' points.
> Network interface + CPU will require re-activation.

I think the problem is only for networked images.  For normal images, it 
would be the same if you were running Windows natively---upgrade CPU, 
and you risk having to do reactivation.

For networked images, does changing CPU twice count as changing one 
thing?  If so that's not too bad, not many things are likely to change 
in a VM beyond the CPU.

Besides, if you have networked images, it's relatively likely that 
you're doing it for a company, hence that you have some kind of MSDN 
subscription which grants you unlimited activations for a given product key.

Paolo