Hi Cedric, > Subject: Re: [PATCH v11 10/10] virtio-gpu-dmabuf: Create dmabuf for > blobs associated with VFIO devices > > Hello Vivek, > > > >>> > >>> On 2026/03/11 11:50, Vivek Kasireddy wrote: > >>>> In addition to memfd, a blob resource can also have its backing > >>>> storage in a VFIO device region. Since, there is no effective way to > >>>> determine where the backing storage is located, we first try to > >>>> create a dmabuf assuming it is in memfd. If that fails, we try to > >>>> create a dmabuf assuming it is in VFIO device region. > >>>> > >>>> So, we first call virtio_gpu_create_udmabuf() to check if the blob's > >>>> backing storage is located in a memfd or not. If it is not, we > >>>> invoke the vfio_device_create_dmabuf_fd() API which identifies > the > >>>> right VFIO device and eventually creates a dmabuf fd. > >>>> > >>>> Note that, for mmapping the dmabuf, we directly call mmap() if > the > >>>> dmabuf fd was created via virtio_gpu_create_udmabuf() since we > >> know > >>>> that the udmabuf driver supports mmap(). However, if the dmabuf > >> was > >>>> created via vfio_device_create_dmabuf_fd(), we use the > >>>> vfio_device_mmap_dmabuf() API to get a mapping for the dmabuf. > >>>> > >>>> Cc: Marc-André Lureau <[email protected]> > >>>> Cc: Alex Bennée <[email protected]> > >>>> Cc: Akihiko Odaki <[email protected]> > >>>> Cc: Dmitry Osipenko <[email protected]> > >>>> Cc: Alex Williamson <[email protected]> > >>>> Cc: Cédric Le Goater <[email protected]> > >>>> Signed-off-by: Vivek Kasireddy <[email protected]> > >>> > >>> Now I think this patch implements proper handling of all error > >>> conditions and conforms the convention. > >>> > >>> Reviewed-by: Akihiko Odaki <[email protected]> > >> Thank you for taking the time to review these patches! > > Can this series be merged to vfio-next given the dependencies on > > the newly added VFIO APIs? > I could merge in advance the VFIO changes but the series does not > apply nor compiles. The current series is based on vfio-next. I'll rebase it on top of Qemu master for the next version.
> We need feedback from the virtio-gpu maintainers > that this proposal is a useful feature too. All the virtio-gpu patches are thoroughly reviewed by Akihiko (who is a virtio-gpu reviewer). > > Since this is QEMU 11.1 material, we have some time. Let me review > it first. Ok, sounds good. Thanks, Vivek > > Thanks, > > C.
