Re: guest / host buffer sharing ...

[David Stevens]

> My question would be "what is the actual problem you are trying to
> solve?".

One problem that needs to be solved is sharing buffers between
devices. With the out-of-tree Wayland device, to share virtio-gpu
buffers we've been using the virtio resource id. However, that
approach isn't necessarily the right approach, especially once there
are more devices allocating/sharing buffers. Specifically, this issue
came up in the recent RFC about adding a virtio video decoder device.

Having a centralized buffer allocator device is one way to deal with
sharing buffers, since it gives a definitive buffer identifier that
can be used by all drivers/devices to refer to the buffer. That being
said, I think the device as proposed is insufficient, as such a
centralized buffer allocator should probably be responsible for
allocating all shared buffers, not just linear guest ram buffers.

-David