diff options
| author | Paolo Bonzini <pbonzini@redhat.com> | 2015-02-10 10:25:44 -0700 |
|---|---|---|
| committer | Alex Williamson <alex.williamson@redhat.com> | 2015-02-10 10:25:44 -0700 |
| commit | 6e48e8f9e0f5b6b15c41f6f8a68c9bf330147d45 (patch) | |
| tree | 581914a4756e758a24b878dcb953d6e758ea19df | |
| parent | a2f2d288b5a06e6c680c387c9980d91363f59c61 (diff) | |
| download | focaccia-qemu-6e48e8f9e0f5b6b15c41f6f8a68c9bf330147d45.tar.gz focaccia-qemu-6e48e8f9e0f5b6b15c41f6f8a68c9bf330147d45.zip | |
memory: unregister AddressSpace MemoryListener within BQL
address_space_destroy_dispatch is called from an RCU callback and hence outside the iothread mutex (BQL). However, after address_space_destroy no new accesses can hit the destroyed AddressSpace so it is not necessary to observe changes to the memory map. Move the memory_listener_unregister call earlier, to make it thread-safe again. Reported-by: Alex Williamson <alex.williamson@redhat.com> Fixes: 374f2981d1f10bc4307f250f24b2a7ddb9b14be0 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
| -rw-r--r-- | exec.c | 6 | ||||
| -rw-r--r-- | include/exec/memory-internal.h | 1 | ||||
| -rw-r--r-- | memory.c | 1 |
3 files changed, 7 insertions, 1 deletions
diff --git a/exec.c b/exec.c index 6b79ad1d11..6dff7bc43a 100644 --- a/exec.c +++ b/exec.c @@ -2059,11 +2059,15 @@ void address_space_init_dispatch(AddressSpace *as) memory_listener_register(&as->dispatch_listener, as); } +void address_space_unregister(AddressSpace *as) +{ + memory_listener_unregister(&as->dispatch_listener); +} + void address_space_destroy_dispatch(AddressSpace *as) { AddressSpaceDispatch *d = as->dispatch; - memory_listener_unregister(&as->dispatch_listener); g_free(d); as->dispatch = NULL; } diff --git a/include/exec/memory-internal.h b/include/exec/memory-internal.h index 25c43c06e9..fb467acdba 100644 --- a/include/exec/memory-internal.h +++ b/include/exec/memory-internal.h @@ -23,6 +23,7 @@ typedef struct AddressSpaceDispatch AddressSpaceDispatch; void address_space_init_dispatch(AddressSpace *as); +void address_space_unregister(AddressSpace *as); void address_space_destroy_dispatch(AddressSpace *as); extern const MemoryRegionOps unassigned_mem_ops; diff --git a/memory.c b/memory.c index 9b91243978..130152cf1d 100644 --- a/memory.c +++ b/memory.c @@ -1978,6 +1978,7 @@ void address_space_destroy(AddressSpace *as) as->root = NULL; memory_region_transaction_commit(); QTAILQ_REMOVE(&address_spaces, as, address_spaces_link); + address_space_unregister(as); /* At this point, as->dispatch and as->current_map are dummy * entries that the guest should never use. Wait for the old |