From 37918ba5b033795f7d3cb121e8df81c78ba6a8b7 Mon Sep 17 00:00:00 2001
From: Paolo Bonzini <pbonzini@redhat.com>
Date: Fri, 2 Mar 2018 08:16:15 -0500
Subject: [PATCH] exec: make address_space_cache_destroy idempotent

Clear cache->mr so that address_space_cache_destroy does nothing
the second time it is called.

Backports commit 91047df38dffa80222179f63fbb74c1dfefa25ed from qemu
---
 qemu/exec.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/qemu/exec.c b/qemu/exec.c
index 7b071766..901d642d 100644
--- a/qemu/exec.c
+++ b/qemu/exec.c
@@ -2474,6 +2474,7 @@ void address_space_cache_destroy(MemoryRegionCache *cache)
     }
 #endif
     memory_region_unref(cache->mr);
+    cache->mr = NULL;
 }
 
 /* Called from RCU critical section.  This function has the same