Follow up to the previous thread.
Summary of the problem: Optimus laptop has all its display outputs hardwired to dGPU. There is no mux or option in BIOS for iGPU to output to anything other than laptop’s builtin monitor. You want to pass GPU through to a virtual machine and use it for prime render offload (not at the same time) without restarting X11 (or Wayland) session.
As explained in the previous thread there is no way to bypass this limitation in hardware. There exist however software solutions. I said solutions (VNC, RDP, X11 forwarding etc.), but for everyday office work you really have only one solution - DisplayLink. It handles creation of new virtual display output/drm device, “tunneling” it over USB port (example), compression and other optimizations that make working with fast moving images (video editing, CAD, memes).
I don’t want to praise DisplayLink too much though. They don’t open source their driver, process is hard to setup and can break on every next linux kernel update (haven’t observed it yet, but will confirm it if it happens). Performance on 1920x1080 screen over USB 3.0 is really good though (can’t see any difference from running via nvidia card). On first day observed 5%-10% CPU usage on idle and spikes to 80%-120% on playing video.
A smarter solution would have been however buying a laptop that has display outputs available for iGPU.
