Comment 2 for bug 1102756

No. It's also not (exclusively) a Mir bug, but is here to simplify not leaking private stuff.

To bulk this out - in system-compositor land, circa 13.04, we'll be entirely ignoring Mir's input stack and having all the X servers talk directly to the input devices. This means we get a fully functioning, tested, input stack without significant effort, but means that all clients of the system compositor get all the input, all the time.

Thus, we need to get XMir to cooperate with switching - XMir needs to know when it loses system-compositor focus and release the input devices. Then, XMir needs to know when it gains system-compositor focus and to acquire the input devices.

There's also the fact that Mir doesn't set the VT to KD_GRAPHICS mode, so the kernel also handles everything you type (which is why hitting Alt-F4 under Mir will VT switch)