5 files changed, 15 insertions, 20 deletions

diff --git a/arch/s390/include/asm/gmap.h b/arch/s390/include/asm/gmap.h
index 58e65ee5b2d2..4a47055f58d7 100644
--- a/arch/s390/include/asm/gmap.h
+++ b/arch/s390/include/asm/gmap.h
@@ -110,8 +110,7 @@ int gmap_shadow_sgt(struct gmap *sg, unsigned long saddr, unsigned long sgt);
 int gmap_shadow_pgt(struct gmap *sg, unsigned long saddr, unsigned long pgt);
 int gmap_shadow_pgt_lookup(struct gmap *sg, unsigned long saddr,
 			   unsigned long *pgt, int *dat_protection);
-int gmap_shadow_page(struct gmap *sg, unsigned long saddr,
-		     unsigned long paddr, int write);
+int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte);
 
 void gmap_register_pte_notifier(struct gmap_notifier *);
 void gmap_unregister_pte_notifier(struct gmap_notifier *);
diff --git a/arch/s390/include/asm/pgtable.h b/arch/s390/include/asm/pgtable.h
index a6e7fc8f5b49..c7ebba483f09 100644
--- a/arch/s390/include/asm/pgtable.h
+++ b/arch/s390/include/asm/pgtable.h
@@ -895,7 +895,7 @@ 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);
 int ptep_shadow_pte(struct mm_struct *mm, unsigned long saddr,
-		    pte_t *sptep, pte_t *tptep, int write);
+		    pte_t *sptep, pte_t *tptep, pte_t pte);
 void ptep_unshadow_pte(struct mm_struct *mm, unsigned long saddr, pte_t *ptep);
 
 bool test_and_clear_guest_dirty(struct mm_struct *mm, unsigned long address);
diff --git a/arch/s390/kvm/gaccess.c b/arch/s390/kvm/gaccess.c
index ba4985262bce..c5f79c1205cf 100644
--- a/arch/s390/kvm/gaccess.c
+++ b/arch/s390/kvm/gaccess.c
@@ -1109,7 +1109,7 @@ int kvm_s390_shadow_fault(struct gmap *sg, unsigned long saddr, int write)
 	dat_protection |= pte.p;
 	if (write && dat_protection)
 		return PGM_PROTECTION;
-	rc = gmap_shadow_page(sg, saddr, pte.pfra * 4096, write);
+	rc = gmap_shadow_page(sg, saddr, __pte(pte.val));
 	if (rc)
 		return rc;
 	return 0;
diff --git a/arch/s390/mm/gmap.c b/arch/s390/mm/gmap.c
index b02d0d0cc641..a57a87bfeb27 100644
--- a/arch/s390/mm/gmap.c
+++ b/arch/s390/mm/gmap.c
@@ -1743,8 +1743,7 @@ EXPORT_SYMBOL_GPL(gmap_shadow_pgt);
  * gmap_shadow_page - create a shadow page mapping
  * @sg: pointer to the shadow guest address space structure
  * @saddr: faulting address in the shadow gmap
- * @paddr: parent gmap address to get mapped at @saddr
- * @write: =1 map r/w, =0 map r/o
+ * @pte: pte in parent gmap address space to get shadowed
  *
  * Returns 0 if successfully shadowed or already shadowed, -EAGAIN if the
  * shadow table structure is incomplete, -ENOMEM if out of memory and
@@ -1752,12 +1751,11 @@ EXPORT_SYMBOL_GPL(gmap_shadow_pgt);
  *
  * Called with sg->mm->mmap_sem in read.
  */
-int gmap_shadow_page(struct gmap *sg, unsigned long saddr,
-		     unsigned long paddr, int write)
+int gmap_shadow_page(struct gmap *sg, unsigned long saddr, pte_t pte)
 {
 	struct gmap *parent;
 	struct gmap_rmap *rmap;
-	unsigned long vmaddr;
+	unsigned long vmaddr, paddr;
 	spinlock_t *ptl;
 	pte_t *sptep, *tptep;
 	int rc;
@@ -1771,6 +1769,7 @@ int gmap_shadow_page(struct gmap *sg, unsigned long saddr,
 	rmap->raddr = (saddr & PAGE_MASK) | _SHADOW_RMAP_PGTABLE;
 
 	while (1) {
+		paddr = pte_val(pte) & PAGE_MASK;
 		vmaddr = __gmap_translate(parent, paddr);
 		if (IS_ERR_VALUE(vmaddr)) {
 			rc = vmaddr;
@@ -1791,8 +1790,7 @@ int gmap_shadow_page(struct gmap *sg, unsigned long saddr,
 				radix_tree_preload_end();
 				break;
 			}
-			rc = ptep_shadow_pte(sg->mm, saddr,
-					     sptep, tptep, write);
+			rc = ptep_shadow_pte(sg->mm, saddr, sptep, tptep, pte);
 			if (rc > 0) {
 				/* Success and a new mapping */
 				gmap_insert_rmap(sg, vmaddr, rmap);
diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c
index 5b02583fbf4c..293130b5aee7 100644
--- a/arch/s390/mm/pgtable.c
+++ b/arch/s390/mm/pgtable.c
@@ -463,29 +463,27 @@ int ptep_force_prot(struct mm_struct *mm, unsigned long addr,
 }
 
 int ptep_shadow_pte(struct mm_struct *mm, unsigned long saddr,
-		    pte_t *sptep, pte_t *tptep, int write)
+		    pte_t *sptep, pte_t *tptep, pte_t pte)
 {
 	pgste_t spgste, tpgste;
 	pte_t spte, tpte;
 	int rc = -EAGAIN;
 
+	if (!(pte_val(*tptep) & _PAGE_INVALID))
+		return 0;	/* already shadowed */
 	spgste = pgste_get_lock(sptep);
 	spte = *sptep;
 	if (!(pte_val(spte) & _PAGE_INVALID) &&
-	    !(pte_val(spte) & _PAGE_PROTECT)) {
-		rc = 0;
-		if (!(pte_val(*tptep) & _PAGE_INVALID))
-			/* Update existing mapping */
-			ptep_flush_direct(mm, saddr, tptep);
-		else
-			rc = 1;
+	    !((pte_val(spte) & _PAGE_PROTECT) &&
+	      !(pte_val(pte) & _PAGE_PROTECT))) {
 		pgste_val(spgste) |= PGSTE_VSIE_BIT;
 		tpgste = pgste_get_lock(tptep);
 		pte_val(tpte) = (pte_val(spte) & PAGE_MASK) |
-			(write ? 0 : _PAGE_PROTECT);
+				(pte_val(pte) & _PAGE_PROTECT);
 		/* don't touch the storage key - it belongs to parent pgste */
 		tpgste = pgste_set_pte(tptep, tpgste, tpte);
 		pgste_set_unlock(tptep, tpgste);
+		rc = 1;
 	}
 	pgste_set_unlock(sptep, spgste);
 	return rc;