s390/mm: prepare for EDAT1/EDAT2 support in gmap shadow

In preparation for EDAT1/EDAT2 support for gmap shadows, we have to store
the requested edat level in the gmap shadow.

The edat level used during shadow translation is a property of the gmap
shadow. Depending on that level, the gmap shadow will look differently for
the same guest tables. We have to store it internally in order to support
it later.

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>

1 files changed, 11 insertions, 5 deletions

diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index a7dfb337e133..f0b2a531c599 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -1382,17 +1382,20 @@ static void gmap_unshadow(struct gmap *sg)
  * gmap_find_shadow - find a specific asce in the list of shadow tables
  * @parent: pointer to the parent gmap
  * @asce: ASCE for which the shadow table is created
+ * @edat_level: edat level to be used for the shadow translation
  *
  * Returns the pointer to a gmap if a shadow table with the given asce is
  * already available, ERR_PTR(-EAGAIN) if another one is just being created,
  * otherwise NULL
  */
-static struct gmap *gmap_find_shadow(struct gmap *parent, unsigned long asce)
+static struct gmap *gmap_find_shadow(struct gmap *parent, unsigned long asce,
+                                     int edat_level)
 {
         struct gmap *sg;
 
         list_for_each_entry(sg, &parent->children, list) {
-                if (sg->orig_asce != asce || sg->removed)
+                if (sg->orig_asce != asce || sg->edat_level != edat_level ||
+                    sg->removed)
                         continue;
                 if (!sg->initialized)
                         return ERR_PTR(-EAGAIN);
@@ -1406,6 +1409,7 @@ static struct gmap *gmap_find_shadow(struct gmap *parent, unsigned long asce)
  * gmap_shadow - create/find a shadow guest address space
  * @parent: pointer to the parent gmap
  * @asce: ASCE for which the shadow table is created
+ * @edat_level: edat level to be used for the shadow translation
  *
  * The pages of the top level page table referred by the asce parameter
  * will be set to read-only and marked in the PGSTEs of the kvm process.
@@ -1416,7 +1420,8 @@ static struct gmap *gmap_find_shadow(struct gmap *parent, unsigned long asce)
  * ERR_PTR(-EAGAIN) if the caller has to retry and ERR_PTR(-EFAULT) if the
  * parent gmap table could not be protected.
  */
-struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce)
+struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce,
+                         int edat_level)
 {
         struct gmap *sg, *new;
         unsigned long limit;
@@ -1424,7 +1429,7 @@ struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce)
 
         BUG_ON(gmap_is_shadow(parent));
         spin_lock(&parent->shadow_lock);
-        sg = gmap_find_shadow(parent, asce);
+        sg = gmap_find_shadow(parent, asce, edat_level);
         spin_unlock(&parent->shadow_lock);
         if (sg)
                 return sg;
@@ -1436,10 +1441,11 @@ struct gmap *gmap_shadow(struct gmap *parent, unsigned long asce)
         new->mm = parent->mm;
         new->parent = gmap_get(parent);
         new->orig_asce = asce;
+        new->edat_level = edat_level;
         new->initialized = false;
         spin_lock(&parent->shadow_lock);
         /* Recheck if another CPU created the same shadow */
-        sg = gmap_find_shadow(parent, asce);
+        sg = gmap_find_shadow(parent, asce, edat_level);
         if (sg) {
                 spin_unlock(&parent->shadow_lock);
                 gmap_free(new);