> Out of curiosity about the big picture, are dmabufs a Linux thing that's independent of OpenGL, or independent of the device driver, They are independent of

> Out of curiosity about the big picture, are dmabufs a Linux thing that's independent of OpenGL, or independent of the device driver, They are independent of the graphics subsystem altogether (although that is where they got their start, afaik). Your webcam also uses DMABUF. So if you want to display your webcam from a GTK 4 application, this GtkGraphicsOffload will help you take that DMABUF from your camera (which may not be mappable on CPU memory, but can DMA pass to your GPU), and display it in a GTK application. It could either be composited on the GPU, or mapped directly to scanout if the right conditions are met. I wrote a library recently (libmks) and found the culprits in Qemu/VirGL/virtio_gpu that were preventing passing a DMABUF from inside a guest VM to the host. That stuff is all fixed now so theoretically you could even have a webcam in a VM which then uses a GTK 4 application to render with VirGL and the compositor submit the scene to the host OS which itself can set the planes correctly to get the same performance as if it were in the host OS. > I'd like to be able to decompress video in one process or docker container on a cloud instance with an NVidia accelerator, and then pass zero-copy references If you want this stuff with NVidia, and you're a customer, I highly suggest you tell your NVidia representative this. Getting them to use DMABUF in a fashion that can be used from other sub-systems would be fantastic. But at it's core, if you were using Mesa and open drivers for some particular piece of hardware, yes it's capable of working given the right conditions.