Re: [Qemu-devel] [patch] kvm: also fill 0x40000000 (vmm) cpuid leafes.

[Gerd Hoffmann <kraxel@redhat.com>]

Anthony Liguori wrote:
> Gerd Hoffmann wrote:
>>   Hi,
>>
>> $subject says all, patch attached.
>>   
> 
> It really doesn't :-)
> 
> 0x4000xxxx are the virtualization leaves, that we don't set so there is
> no functional change from this patch.

Not yet.  For now it hasn't any effect.  I can keep it in my patch queue
until I submit the patches depending on that one.  But I expect more
users that xenner, so I thought it might be useful for others too and
submitted it right away ...

> The KVM PV ABI doesn't use eax as
> the max CPUID leaf of 0x40000000 so that's at least one example of them
> not behaving like this.

Oops.  I think we should fix it then to follow the usual eax convention.
 Xenner (standalone version, not qemu-integrated) actually does that and
sets eax to KVM_CPUID_FEATURES.

> So can you be a lot more specific about how you intend on using these
> leaves?

qemu-integrated xenner can handle full virtualized guests with xen pv
drivers installed.  Must provide xen virt cpuid leaves then.

cheers,
  Gerd