[RFC v1 2/4] virtio-gpu uapi: Add VIRTIO_GPU_F_OUT_FENCE feature

[Gerd Hoffmann]

On Thu, Jul 29, 2021 at 01:16:57AM -0700, Vivek Kasireddy wrote:
> This feature enables the Guest to wait to know when a resource
> is completely consumed by the Host.

virtio spec update?

What are the exact semantics?

Why a new command?  Can't you simply fence one of the commands sent
anyway (set_scanout probably for page-flip updates)?

(feature flag is probably needed even in case we don't need a new
command to make sure the host sends the completion when processing
the command is actually done, i.e. in case of qemu the recently added
fence support is there).

take care,
  Gerd