I'm less than keen on having kernel memory space used for spare VC
maps. Surely the window manager should look after them. The linux kernel
is getting big enough without this.
I think a pair of functions would solve the entire problem neatly
and elegantly. Firstly the ability to open a raw keystroke device or
at least monitor the special switch-vc functions, so that X and MGR
can opt to watch for ALT-F1/2/... without the console stealing them.
Secondly all that is needed on top of the current code is an ioctl
on virtual consoles to select console. Thus the flow for graphics screens
is now

User presses ALT-F2
Kernel ignores it (graphics mode screen - this is already in)
X sees ALT-F2
X dumps screen to memory or to a file, or even discards it
X returns to text mode
X does ioctl to switch to VC 2 maybe sending SIGWINCH
VC 2 wakes up sees SIGWINCH and being MGR goes graphic mode
reloads the MGR display and carries on...

A lot less kernel code than the alternative.

Alan