diff options
author | Carsten Otte <cotte@de.ibm.com> | 2008-03-25 13:47:10 -0400 |
---|---|---|
committer | Avi Kivity <avi@qumranet.com> | 2008-04-27 05:00:40 -0400 |
commit | 402b08622d9ac6e32e25289573272e0f21bb58a7 (patch) | |
tree | 40d7386154cef85c9bfd2bd862db025933820776 /include/asm-s390/pgtable.h | |
parent | 37817f2982d0f559f90cecc66e150dd9d2c2df05 (diff) |
s390: KVM preparation: provide hook to enable pgstes in user pagetable
The SIE instruction on s390 uses the 2nd half of the page table page to
virtualize the storage keys of a guest. This patch offers the s390_enable_sie
function, which reorganizes the page tables of a single-threaded process to
reserve space in the page table:
s390_enable_sie makes sure that the process is single threaded and then uses
dup_mm to create a new mm with reorganized page tables. The old mm is freed
and the process has now a page status extended field after every page table.
Code that wants to exploit pgstes should SELECT CONFIG_PGSTE.
This patch has a small common code hit, namely making dup_mm non-static.
Edit (Carsten): I've modified Martin's patch, following Jeremy Fitzhardinge's
review feedback. Now we do have the prototype for dup_mm in
include/linux/sched.h. Following Martin's suggestion, s390_enable_sie() does now
call task_lock() to prevent race against ptrace modification of mm_users.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Carsten Otte <cotte@de.ibm.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Avi Kivity <avi@qumranet.com>
Diffstat (limited to 'include/asm-s390/pgtable.h')
-rw-r--r-- | include/asm-s390/pgtable.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/asm-s390/pgtable.h b/include/asm-s390/pgtable.h index 65154dc9a9e5..8e9a629dc199 100644 --- a/include/asm-s390/pgtable.h +++ b/include/asm-s390/pgtable.h | |||
@@ -966,6 +966,7 @@ static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset) | |||
966 | 966 | ||
967 | extern int add_shared_memory(unsigned long start, unsigned long size); | 967 | extern int add_shared_memory(unsigned long start, unsigned long size); |
968 | extern int remove_shared_memory(unsigned long start, unsigned long size); | 968 | extern int remove_shared_memory(unsigned long start, unsigned long size); |
969 | extern int s390_enable_sie(void); | ||
969 | 970 | ||
970 | /* | 971 | /* |
971 | * No page table caches to initialise | 972 | * No page table caches to initialise |