--- old/src/hotspot/share/gc/z/zVirtualMemory.hpp	2018-01-17 11:44:04.029421322 +0900
+++ new/src/hotspot/share/gc/z/zVirtualMemory.hpp	2018-01-17 11:44:03.890418948 +0900
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2015, 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -28,6 +28,8 @@
 #include "memory/allocation.hpp"
 
 class ZVirtualMemory VALUE_OBJ_CLASS_SPEC {
+  friend class VMStructs;
+
 private:
   uintptr_t _start;
   uintptr_t _end;