Hello Vivek,
On 3/17/26 06:42, Kasireddy, Vivek wrote:
Hi Cedric,
Subject: RE: [PATCH v11 10/10] virtio-gpu-dmabuf: Create dmabuf for
blobs associated with VFIO devices
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. We need feedback from the virtio-gpu maintainers
that this proposal is a useful feature too.
Since this is QEMU 11.1 material, we have some time. Let me review
it first.
Thanks,
C.
