diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c
index d97b3ea4af..945e7acb5e 100644
--- a/xen/arch/arm/mm.c
+++ b/xen/arch/arm/mm.c
@@ -612,6 +612,10 @@ static int xenmem_add_to_physmap_range(struct domain *d,
                                        xatpr->foreign_domid,
                                        idx, gpfn);
 
+        rc = copy_to_guest_offset(xatpr->errs, xatpr->size-1, &rc, 1);
+        if ( rc < 0 )
+            goto out;
+
         xatpr->size--;
 
         /* Check for continuation if it's not the last interation */
diff --git a/xen/include/public/memory.h b/xen/include/public/memory.h
index 3ee290208d..62acabd021 100644
--- a/xen/include/public/memory.h
+++ b/xen/include/public/memory.h
@@ -236,6 +236,7 @@ DEFINE_XEN_GUEST_HANDLE(xen_add_to_physmap_t);
 /* A batched version of add_to_physmap. */
 #define XENMEM_add_to_physmap_range 23
 struct xen_add_to_physmap_range {
+    /* IN */
     /* Which domain to change the mapping for. */
     domid_t domid;
     uint16_t space; /* => enum phys_map_space */
@@ -247,8 +248,13 @@ struct xen_add_to_physmap_range {
     /* Indexes into space being mapped. */
     XEN_GUEST_HANDLE(xen_ulong_t) idxs;
 
-    /* GPFN in domdwhere the source mapping page should appear. */
+    /* GPFN in domid where the source mapping page should appear. */
     XEN_GUEST_HANDLE(xen_pfn_t) gpfns;
+
+    /* OUT */
+
+    /* Per index error code. */
+    XEN_GUEST_HANDLE(int) errs;
 };
 typedef struct xen_add_to_physmap_range xen_add_to_physmap_range_t;
 DEFINE_XEN_GUEST_HANDLE(xen_add_to_physmap_range_t);