Re: [Xen-devel] [PATCH 3/3] x86/xen: use guest_late_init to detect Xen PVH guest

[Paolo Bonzini]

On 08/11/2017 13:24, Juergen Gross wrote:
>> My understanding of Xen is very rusty at this point, but I think a
>> "completely" legacy-free HVM domain will still have a PCI bus and the
>> Xen platform device on that bus.
>>
>> A PVH domain just knows how to access the Xen PV features.
>
> A HVM domain does so, too. Today maybe only partially, but e.g. event
> channels work in a HVM domain even without the Xen platform device.
> Grant tables can be made working without the platform device, too,
> and I'm already preparing a patch to do exactly that.

What about assigned PCI devices?  I think they are not PV pcifront for
HVM.  So the main difference in the end is the PCI bus.

Paolo