On Wed, 2014-09-17 at 09:07 -0700, Andy Lutomirski wrote: > It shouldn't. That being said, at some point this problem will need > solving on PPC, and this patch doesn't help much, other than adding > the virtio_ring piece. > > I'd really like to see the generic or arch IOMMU code handle this so > that the PPC special case in the virtio-pci driver can go away. > > Another reason that this kind of special casing doesn't belong in > virtio-pci: if anyone ever binds vfio to a virtio-pci device, if the > DMA API doesn't work right, then the kernel will go boom or be > compromised. Well, that's also for these reasons that I think your patch shouldn't go through those virtio_* variants that test that "use_dma_api" flag or whatever you called it last time I looked :-) You should just unconditionally call the DMA API and we should fixup the special cases by overriding the hooks. I can help you do the override hack for PPC for now, until we can do something saner accross all architectures. The main problem is s390 but I had a quick chat with Utz Bacher earlier this week and he seemed to think having s390 use the DMA API shouldn't be a big deal, they can also hookup some transparent set of ops if necessary. Cheers, Ben. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
