Re: xen drivers to use virtio?

[Anthony Liguori <anthony@codemonkey.ws>]

Jeremy Fitzhardinge wrote:
> Jun Koi wrote:
>> If I understand correctly, we are going to rewrite some xen drivers in
>> Linux kernel to use virtio once virtio is stable. Is that true?
>>   
> 
> There are no plans to do so.

Actually, they're already there to some degree now that qemu-dm is 
tracking the upstream QEMU tree.  virtio support has been in the QEMU 
tree for some time now.  If it's not enabled in qemu-dm by default, it 
should be trivial to enable.  From Xend's perspective, virtio devices 
shouldn't be different from either rtl8139, e1000, etc.  It's just 
another PCI device.

This model makes less sense in the context of stub domains, but if 
you're running qemu-dm in dom0, you may actually get reasonable 
performance out of the virtio drivers.

In fact, comparing an HVM domain using virtio with qemu-dm in dom0 
verses netfront ala PV-on-HVM would make for a very interesting comparison.

And assuming PV-on-HVM isn't in upstream Linux yet (that appears to be 
the case) and virtio is, it may even be a practical thing to do.

Regards,

Anthony Liguori


>    J