Linux Multi-Seat Gaming: Fixing Input Isolation with LIBSEAT_BACKEND=noop (Part 3)
The Problem Part 2 ended with a gamescope TV session that could be started and stopped independently - but with an immediate new problem: moving the desk mouse moved the cursor in Steam Big Picture on the TV. Keyboard keys navigated Steam menus. This shouldn’t happen. The desk mouse and keyboard are seat0 devices - they are not tagged for seat1 in udev, so seatd should not have given gamescope access to them. The gamescope log confirmed this - there were no “Adding device” messages from libinput. gamescope itself received no input devices through seatd. ...