Frame capture support in KMS driver.

[hgaiser]

I am developing an application to stream games over the local network. This currently uses NvFBC for frame capturing, but this means it only works using X11 and only for NVIDIA's GPUs. Capturing frames in Wayland is possible on other hardware using the KMS driver, through libdrm.

NVIDIA's GPUs do have a KMS driver, but the functionality for retrieving the latest frame is not implemented.

Would it be possible to implement such functionality in the open source driver?

For reference: a minimal example for capturing frames from a KMS driver: https://github.com/jsastriawan/kmsfbshot/blob/master/kmsfbshot.c