Alex Bennée via Stratos-dev stratos-dev@op-lists.linaro.org writes:
Alyssa Ross hi@alyssa.is writes:
As I understand it, virtio-wayland is effectively deprecated in favour of sending Wayland messages over cross-domain virtio-gpu contexts. It's possible to do this now with an upstream kernel, whereas virtio-wayland always required a custom driver in the Chromium kernel.
That's good to know. I guess there is nothing that prevents the final display of virtual GPUs from multiple guests being mapped onto the final presentation? The automotive use case seems to treat each individual VM with a UI as presenting a surface which the final console manager composites up together depending on safety rules to display to the user.
Well, in the Wayland use case, AIUI virtio-gpu is just a transport for the Wayland protocol + shared memory resources. The simplest case is just sending shared CPU memory buffers around (wl_shm), so there's not really any GPU involved in anything but name. Alternatively, it's possible to use dma-bufs, and graphics acceleration through the virtio-gpu devices, and yes, when doing that it's still possible for the host Wayland compositor to combine everything into one presentation — I think they're all just dma-bufs to it.
Does that make sense? I'm also no expert on this but hopefully I'm not too far off.