From: Alex Williamson <alex.williamson@redhat.com>

The below referenced commit renames scanout_width/height to
backing_width/height, but also promotes these fields in various portions
of the egl interface.  Meanwhile vfio dmabuf support has never used the
previous scanout fields and is therefore missed in the update.  This
results in a black screen when transitioning from ramfb to dmabuf display
when using Intel vGPU with these features.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1891
Link: https://lists.gnu.org/archive/html/qemu-devel/2023-08/msg02726.html
Fixes: 9ac06df8b684 ("virtio-gpu-udmabuf: correct naming of QemuDmaBuf size properties")
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Tested-by: Cédric Le Goater <clg@redhat.com>
Signed-off-by: Cédric Le Goater <clg@redhat.com>
---
 hw/vfio/display.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/hw/vfio/display.c b/hw/vfio/display.c
index bec864f482f46866bf292a5a63c31753a7c84eef..837d9e6a309e834601c125e36faadf81c1c5172e 100644
--- a/hw/vfio/display.c
+++ b/hw/vfio/display.c
@@ -243,6 +243,8 @@ static VFIODMABuf *vfio_display_get_dmabuf(VFIOPCIDevice *vdev,
     dmabuf->dmabuf_id  = plane.dmabuf_id;
     dmabuf->buf.width  = plane.width;
     dmabuf->buf.height = plane.height;
+    dmabuf->buf.backing_width = plane.width;
+    dmabuf->buf.backing_height = plane.height;
     dmabuf->buf.stride = plane.stride;
     dmabuf->buf.fourcc = plane.drm_format;
     dmabuf->buf.modifier = plane.drm_format_mod;
-- 
2.41.0