On Sun, 2015-10-25 at 19:55 -0700, Andy Lutomirski wrote:
> It would be nice to nail down how virtio should interact with IOMMUs
> on the emulated busses.  A bunch of the relevant maintainers are
> around, and a short slot for this topic might make sense.
> 
> The goal would be to figure out how to accomplish something like this
> series:
> 
> https://git.kernel.org/cgit/linux/kernel/git/luto/linux.git/log/?h=vi
> rtio_ring_xen
> 
> but in a way that would actually work on all supported platforms
> without breaking backward compatibility or killing performance.

FWIW it should be fine with VT-d; we already cope with the concept that
*some* devices don't have translation, while others do. If we don't
have DMA translation for the virtio devices, that works out fine.

I think the main problem is on POWER where they don't yet have that
option.

-- 
David Woodhouse                            Open Source Technology Centre
David.Woodhouse@intel.com                              Intel Corporation