mm: vm: Start testing the VM system

Maybe it could have been handier to do this a little earlier, but better
late than never, my mum always says.

The most simple test you can think of, a plain data dump. I think I
already have the first bug this way. That'll be for the next commit
though.

Signed-off-by: Bart Kuivenhoven <bemkuivenhoven@gmail.com>