Comment 12 for bug 1670670

Whatever the solution, we need to be aware that a stylus can jump all over the screen but also move like a normal mouse cursor if it's in close proximity to (even not touching) the screen. The shell has no say in the movement then because the cursor needs to match the real-world stylus position, even when moving like a mouse.

I think that's the kind of device Qemu is emulating but also suspect Qemu's fake tablet is more complicated than that -- a mouse rather than a tablet, which emits absolute coordinates that can suddenly appear from any side of the virtual screen.