Now that NVidia have released the kernel modules open source there is no longer anything stopping the use of GPL symbols such as DMABUF.
While NVidia’s driver reports to have DMABUF support already, it’s not true DMABUF, but instead some proprietary thing which is incompatible preventing import of buffers from non NVidia sources/devices. I can only assume this was done to get Wayland working without violating the GPL license.
We already have full DMABUF support on Intel and AMD GPUs and applications such as Wayland and Looking Glass are able to take full advantage of them offloading texture transfers from the CPU to the GPU’s DMA engine.
Please show your support and desire for this feature on the GitHub issue I have created over here, lets make NVidia know how many people need this!