On Thu, May 14, 2020 at 11:08:52AM +0900, David Stevens wrote: > On Thu, May 14, 2020 at 12:45 AM Daniel Vetter <daniel@xxxxxxxx> wrote: > > On Wed, Mar 11, 2020 at 12:20 PM David Stevens <stevensd@xxxxxxxxxxxx> wrote: > > > > > > This change adds a new dma-buf operation that allows dma-bufs to be used > > > by virtio drivers to share exported objects. The new operation allows > > > the importing driver to query the exporting driver for the UUID which > > > identifies the underlying exported object. > > > > > > Signed-off-by: David Stevens <stevensd@xxxxxxxxxxxx> > > > > Adding Tomasz Figa, I've discussed this with him at elce last year I > > think. Just to make sure. > > > > Bunch of things: > > - obviously we need the users of this in a few drivers, can't really > > review anything stand-alone > > Here is a link to the usage of this feature by the currently under > development virtio-video driver: > https://markmail.org/thread/j4xlqaaim266qpks > > > - adding very specific ops to the generic interface is rather awkward, > > eventually everyone wants that and we end up in a mess. I think the > > best solution here would be if we create a struct virtio_dma_buf which > > subclasses dma-buf, add a (hopefully safe) runtime upcasting > > functions, and then a virtio_dma_buf_get_uuid() function. Just storing > > the uuid should be doable (assuming this doesn't change during the > > lifetime of the buffer), so no need for a callback. > > So you would prefer a solution similar to the original version of this > patchset? https://markmail.org/message/z7if4u56q5fmaok4 yup. -Daniel -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch
