[Qemu-devel] [PATCH 1/9] memory: make memory_listener_unregister idempotent

[Paolo Bonzini <pbonzini@redhat.com>]

Make it easy to unregister a MemoryListener without tracking whether it
had been registered before.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
	v3: new

 memory.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/memory.c b/memory.c
index 2bfc37f..8fafd4c 100644
--- a/memory.c
+++ b/memory.c
@@ -2371,8 +2371,13 @@ void memory_listener_register(MemoryListener *listener, AddressSpace *as)
 
 void memory_listener_unregister(MemoryListener *listener)
 {
+    if (!listener->address_space) {
+        return;
+    }
+
     QTAILQ_REMOVE(&memory_listeners, listener, link);
     QTAILQ_REMOVE(&listener->address_space->listeners, listener, link_as);
+    listener->address_space = NULL;
 }
 
 void address_space_init(AddressSpace *as, MemoryRegion *root, const char *name)
-- 
1.8.3.1