On Sun, Aug 11, 2019 at 04:55:27AM -0400, Michael S. Tsirkin wrote: > On Sun, Aug 11, 2019 at 07:56:07AM +0200, Christoph Hellwig wrote: > > So we need a flag on the virtio device, exposed by the > > hypervisor (or hardware for hw virtio devices) that says: hey, I'm real, > > don't take a shortcut. > > The point here is that it's actually still not real. So we would still > use a physical address. However Linux decides that it wants extra > security by moving all data through the bounce buffer. The distinction > made is that one can actually give device a physical address of the > bounce buffer. Sure. The problem is just that you keep piling hacks on top of hacks. We need the per-device flag anyway to properly support hardware virtio device in all circumstances. Instead of coming up with another ad-hoc hack to force DMA uses implement that one proper bit and reuse it here. _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
