[PATCH 00/11] drm/virtio: fixes and cleanups for vbuf queuing

[Chia-I Wu]

This series consists of fixes and cleanups for
virtio_gpu_queue_fenced_ctrl_buffer, except for the last patch.  The fixes are
for corner cases that were overlooked.  The cleanups make the last patch
easier, but they should be good in themselves as well.

The last patch changes the disable_notify mechanism to call
virtqueue_kick_prepare only once in virtio_gpu_enable_notify.  It should be
more efficient than doing that after each command is queued.

There is a follow-up patch that replaces the global disable_notify state by
command-level bools to disable notify for individual commands, so that one
process cannot affect another process.  I can include it in v2 if you want to
review it together with this series.