> > > Of course only virtio drivers would try step (2), other drivers (when > > > sharing buffers between intel gvt device and virtio-gpu for example) > > > would go straight to (3). > > > > For virtio-gpu as it is today, it's not clear to me that they're > > equivalent. As I read it, the virtio-gpu spec makes a distinction > > between the guest memory and the host resource. If virtio-gpu is > > communicating with non-virtio devices, then obviously you'd just be > > working with guest memory. But if it's communicating with another > > virtio device, then there are potentially distinct guest and host > > buffers that could be used. The spec shouldn't leave any room for > > ambiguity as to how this distinction is handled. > > Yep. It should be the host side buffer. I agree that it should be the host side buffer. I just want to make sure that the meaning of 'import' is clear, and to establish the fact that importing a buffer by uuid is not necessarily the same thing as creating a new buffer in a different device from the same sglist (for example, sharing a guest sglist might require more flushes). -David
