s390/mm: extended gmap pte notifier

The current gmap pte notifier forces a pte into to a read-write state.
If the pte is invalidated the gmap notifier is called to inform KVM
that the mapping will go away.

Extend this approach to allow read-write, read-only and no-access
as possible target states and call the pte notifier for any change
to the pte.

This mechanism is used to temporarily set specific access rights for
a pte without doing the heavy work of a true mprotect call.

Reviewed-by: David Hildenbrand <dahi@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
This commit is contained in:
Martin Schwidefsky
2016-03-08 11:54:42 +01:00
committed by Christian Borntraeger
parent 8ecb1a59d6
commit b2d73b2a0a
5 changed files with 193 additions and 55 deletions

View File

@@ -59,8 +59,11 @@ void gmap_discard(struct gmap *, unsigned long from, unsigned long to);
void __gmap_zap(struct gmap *, unsigned long gaddr);
void gmap_unlink(struct mm_struct *, unsigned long *table, unsigned long vmaddr);
void gmap_register_ipte_notifier(struct gmap_notifier *);
void gmap_unregister_ipte_notifier(struct gmap_notifier *);
int gmap_ipte_notify(struct gmap *, unsigned long start, unsigned long len);
void gmap_register_pte_notifier(struct gmap_notifier *);
void gmap_unregister_pte_notifier(struct gmap_notifier *);
void gmap_pte_notify(struct mm_struct *, unsigned long addr, pte_t *);
int gmap_mprotect_notify(struct gmap *, unsigned long start,
unsigned long len, int prot);
#endif /* _ASM_S390_GMAP_H */

View File

@@ -886,6 +886,8 @@ void ptep_set_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t entry);
void ptep_set_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
void ptep_notify(struct mm_struct *mm, unsigned long addr, pte_t *ptep);
int ptep_force_prot(struct mm_struct *mm, unsigned long gaddr,
pte_t *ptep, int prot);
void ptep_zap_unused(struct mm_struct *mm, unsigned long addr,
pte_t *ptep , int reset);
void ptep_zap_key(struct mm_struct *mm, unsigned long addr, pte_t *ptep);