leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

s390/mm: support real-space for gmap shadows

Browse Source 
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>
This commit is contained in:
David Hildenbrand
2016-04-18 16:22:24 +02:00
committed by Christian Borntraeger
parent 1c65781b56
commit 3218f7094b
3 changed files with 65 additions and 10 deletions
Download Patch File Download Diff File Expand all files Collapse all files

6
arch/s390/include/asm/gmap.h
View File

@@ -109,8 +109,10 @@ int gmap_read_table(struct gmap *gmap, unsigned long gaddr, unsigned long *val);
struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
int edat_level);
int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t);
int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t);
int gmap_shadow_r2t(struct gmap *sg, unsigned long saddr, unsigned long r2t,
int fake);
int gmap_shadow_r3t(struct gmap *sg, unsigned long saddr, unsigned long r3t,
int fake);
int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt,
int fake);
int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt,