tree 4ebcd767692fccf684503c8202c00cc87dba3472
parent 1c65781b56ce812ce9729bf414201921c9408678
author David Hildenbrand <dahi@linux.vnet.ibm.com> 1460989344 +0200
committer Christian Borntraeger <borntraeger@de.ibm.com> 1466409302 +0200

s390/mm: support real-space for gmap shadows

We can easily support real-space designation just like EDAT1 and EDAT2.
So guest2 can provide for guest3 an asce with the real-space control being
set.

We simply have to allocate the biggest page table possible and fake all
levels.

There is no protection to consider. If we exceed guest memory, vsie code
will inject an addressing exception (via program intercept). In the future,
we could limit the fake table level to the gmap page table.

As the top level page table can never go away, such gmap shadows will never
get unshadowed, we'll have to come up with another way to limit the number
of kept gmap shadows.

Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>