s390/kvm: Add PGSTE manipulation functions

Add PGSTE manipulation functions:
* set_pgste_bits sets specific bits in a PGSTE
* get_pgste returns the whole PGSTE
* pgste_perform_essa manipulates a PGSTE to set specific storage states
* ESSA_[SG]ET_* macros used to indicate the action for manipulate_pgste

Signed-off-by: Claudio Imbrenda <imbrenda@linux.vnet.ibm.com>
Reviewed-by: Janosch Frank <frankja@de.ibm.com>
Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

1 files changed, 12 insertions, 4 deletions

diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index 93e37b12e882..bdabbbb3e925 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -372,10 +372,12 @@ static inline int is_module_addr(void *addr)
 #define PGSTE_VSIE_BIT  0x0000200000000000UL    /* ref'd in a shadow table */
 
 /* Guest Page State used for virtualization */
-#define _PGSTE_GPS_ZERO         0x0000000080000000UL
-#define _PGSTE_GPS_USAGE_MASK   0x0000000003000000UL
-#define _PGSTE_GPS_USAGE_STABLE 0x0000000000000000UL
-#define _PGSTE_GPS_USAGE_UNUSED 0x0000000001000000UL
+#define _PGSTE_GPS_ZERO                 0x0000000080000000UL
+#define _PGSTE_GPS_USAGE_MASK           0x0000000003000000UL
+#define _PGSTE_GPS_USAGE_STABLE         0x0000000000000000UL
+#define _PGSTE_GPS_USAGE_UNUSED         0x0000000001000000UL
+#define _PGSTE_GPS_USAGE_POT_VOLATILE   0x0000000002000000UL
+#define _PGSTE_GPS_USAGE_VOLATILE       _PGSTE_GPS_USAGE_MASK
 
 /*
  * A user page table pointer has the space-switch-event bit, the
@@ -1041,6 +1043,12 @@ int reset_guest_reference_bit(struct mm_struct *mm, unsigned long addr);
 int get_guest_storage_key(struct mm_struct *mm, unsigned long addr,
                           unsigned char *key);
 
+int set_pgste_bits(struct mm_struct *mm, unsigned long addr,
+                                unsigned long bits, unsigned long value);
+int get_pgste(struct mm_struct *mm, unsigned long hva, unsigned long *pgstep);
+int pgste_perform_essa(struct mm_struct *mm, unsigned long hva, int orc,
+                        unsigned long *oldpte, unsigned long *oldpgste);
+
 /*
  * Certain architectures need to do special things when PTEs
  * within a page table are directly modified.  Thus, the following