diff --git a/xen/arch/x86/x86_64/compat/mm.c b/xen/arch/x86/x86_64/compat/mm.c
index f497503769..fb7baca2e2 100644
--- a/xen/arch/x86/x86_64/compat/mm.c
+++ b/xen/arch/x86/x86_64/compat/mm.c
@@ -66,21 +66,20 @@ int compat_arch_memory_op(int op, XEN_GUEST_HANDLE(void) arg)
         XLAT_add_to_physmap(nat, &cmp);
         rc = arch_memory_op(op, guest_handle_from_ptr(nat, void));
 
-        if ( cmp.space == XENMAPSPACE_gmfn_range )
+        if ( !rc || cmp.space != XENMAPSPACE_gmfn_range )
+            break;
+
+        XLAT_add_to_physmap(&cmp, nat);
+        if ( __copy_to_guest(arg, &cmp, 1) )
         {
-            if ( rc )
-            {
-                XLAT_add_to_physmap(&cmp, nat);
-                if ( copy_to_guest(arg, &cmp, 1) )
-                {
-                    hypercall_cancel_continuation();
-                    return -EFAULT;
-                }
-            }
             if ( rc == __HYPERVISOR_memory_op )
-                hypercall_xlat_continuation(NULL, 0x2, nat, arg);
+                hypercall_cancel_continuation();
+            return -EFAULT;
         }
 
+        if ( rc == __HYPERVISOR_memory_op )
+            hypercall_xlat_continuation(NULL, 0x2, nat, arg);
+
         break;
     }