On Thu, Feb 02, 2017 at 06:30:28PM +0200, Michael S. Tsirkin wrote:

I am inclined to say, for 4.10 let's revert
c7070619f3408d9a0dffbed9149e6f00479cf43b since what it fixes is not a
regression in 4.10.

No complaints there, as long as we can keep working to fix this for 4.11
and onwards. You'll also need to cc stable on the revert.

So I think we can defer the fix to 4.11.
I think we still want f7f6634d23830ff74335734fbdb28ea109c1f349
for hosts with virtio 1 support.

All this will hopefully push hosts to just implement virtio 1.
For mmio the changes are very small: several new registers,
that's all. You want this for proper 64 bit dma mask anyway.

As I've said, virtio 1 will have exactly the same issue unless we start
requiring firmware to advertise dma-coherent/_CCA for virtio-mmio
devices correctly.

Will