Update 1
I believe the feature you are looking for is actually X Window multi-pointer.
From ArchLinux Multi-Pointer X Introduction:
Xorg servers starting from version 1.7 have a feature called "multi-pointer". Basically it allows to have multiple mouse cursors (each with its own keyboard focus) on the screen and control them with separate physical input devices. It can be used as a crude multiseat solution.
Check out following links
- Multi-Pointer X Wikipedia
- ArchLinux Multi-Pointer X
Original Answer
I saw various of those setup in the past (in term of years). So it is definitly doable. No need to re-write kenrel or x windows.
Doing a google search with linux multiple mouse pointers
, come up with multiple pages. Following is one of them
- linux: dual mice - multiple mice with multiple mouse pointers?linux: dual mice - multiple mice with multiple mouse pointers? A stackoverflow question asked and answer in 2010.
- multiple mouse / keyboard in linux which is a blog post.
Those are only 2 of many that come up.
If you search for linux multi-seat
, you will get links for one linux box supporting multiple KVM (keyboard+video+mouse). Following is one of them
So the technology is definitely already available, but how far you can go, or how they suit your need, you will have to spend sometime to research and experiment.