Re: [Qemu-devel] [PATCH RFC v1 2/2] hyper-v: initialize Hyper-V CPUID leafs.

[Paolo Bonzini]

On 10/17/2011 12:41 PM, Avi Kivity wrote:
> >  Even not counting that hyper-v support should IMHO not be in
> >  KVM-specific code, I still think this shouldn't remove KVM leaves
> >  completely but rather move them to 0x40000100.  The KVM
> >  paravirtualization code then can similarly probe with 0x100 stride up
> >  to 0x40001000.  This is what was done for Xen, and it allows to enable
> >  enlightenments independent of whether the guest is Linux or Windows.
> >
> >  However, let's get a third opinion---Avi, what do you think?
>
> I agree with you, especially as this already works for Xen.
>
> Note it doesn't completely solve the issue (so we have two interfaces,
> which is the preferred one?), but it's better than nothing.

Windows doesn't look beyond 0x40000000, so Hyper-V stays there and KVM 
has to shift.  So MS solved that part for us. :)

Paolo