Re: [Qemu-devel] [PATCH v5 01/11] memory: Sanity check that no listeners remain on a destroyed AddressSpace

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 03/20/2014 09:20 PM, Paolo Bonzini wrote:
> Il 12/03/2014 06:52, Alexey Kardashevskiy ha scritto:
>> From: David Gibson <david@gibson.dropbear.id.au>
>>
>> At the moment, most AddressSpace objects last as long as the guest system
>> in practice, but that could well change in future.  In addition, for VFIO
>> we will be introducing some private per-AdressSpace information, which must
>> be disposed of before the AddressSpace itself is destroyed.
>>
>> To reduce the chances of subtle bugs in this area, this patch adds
>> asssertions to ensure that when an AddressSpace is destroyed, there are no
>> remaining MemoryListeners using that AS as a filter.
>>
>> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>> ---
>>  memory.c | 7 +++++++
>>  1 file changed, 7 insertions(+)
>>
>> diff --git a/memory.c b/memory.c
>> index 3f1df23..678661e 100644
>> --- a/memory.c
>> +++ b/memory.c
>> @@ -1722,12 +1722,19 @@ void address_space_init(AddressSpace *as,
>> MemoryRegion *root, const char *name)
>>
>>  void address_space_destroy(AddressSpace *as)
>>  {
>> +    MemoryListener *listener;
>> +
>>      /* Flush out anything from MemoryListeners listening in on this */
>>      memory_region_transaction_begin();
>>      as->root = NULL;
>>      memory_region_transaction_commit();
>>      QTAILQ_REMOVE(&address_spaces, as, address_spaces_link);
>>      address_space_destroy_dispatch(as);
>> +
>> +    QTAILQ_FOREACH(listener, &memory_listeners, link) {
>> +        assert(listener->address_space_filter != as);
>> +    }
>> +
>>      flatview_unref(as->current_map);
>>      g_free(as->name);
>>      g_free(as->ioeventfds);
>>
> 
> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>


What happens next to this patch and the next one ("int128: add
int128_exts64()")? I mean who you expect to pull them? Alex Graf? :) Thanks.


> 
> An alternative is to add a count of listeners to the address space and
> assert that it is 0.
> 
> Paolo




-- 
Alexey