s390/kvm: Provide function for setting the guest storage key

From time to time we need to set the guest storage key. Lets
provide a helper function that handles the changes with all the
right locking and checking.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h
index 590c3219c634..e1408ddb94f8 100644
--- a/arch/s390/include/asm/pgalloc.h
+++ b/arch/s390/include/asm/pgalloc.h
@@ -22,6 +22,9 @@ unsigned long *page_table_alloc(struct mm_struct *, unsigned long);
 void page_table_free(struct mm_struct *, unsigned long *);
 void page_table_free_rcu(struct mmu_gather *, unsigned long *);
 
+int set_guest_storage_key(struct mm_struct *mm, unsigned long addr,
+                          unsigned long key, bool nq);
+
 static inline void clear_table(unsigned long *s, unsigned long val, size_t n)
 {
         typedef struct { char _[n]; } addrtype;