Re: [Qemu-devel] [PATCH qemu v10 12/14] vfio: Unregister IOMMU notifiers when container is destroyed

[Alexey Kardashevskiy <aik@ozlabs.ru>]

On 07/06/2015 10:49 PM, Alex Williamson wrote:
> On Mon, 2015-07-06 at 20:33 +1000, David Gibson wrote:
>> On Mon, Jul 06, 2015 at 12:11:08PM +1000, Alexey Kardashevskiy wrote:
>>> On systems with guest visible IOMMU, adding a new memory region onto
>>> PCI bus calls vfio_listener_region_add() for every DMA window. This
>>> installs a notifier for IOMMU memory regions. The notifier is supposed
>>> to be removed by vfio_listener_region_del(), however in the case of mixed
>>> PHB (emulated + VFIO devices) when last VFIO device is unplugged and
>>> container gets destroyed, all existing DMA windows stay alive altogether
>>> with the notifiers which are on the linked list which head was in
>>> the destroyed container.
>>>
>>> This unregisters IOMMU memory region notifier when a container is
>>> destroyed.
>>>
>>> Signed-off-by: Alexey Kardashevskiy <aik@ozlabs.ru>
>>
>> Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
>>
>> Alex,
>>
>> I think this is correct, but you've probably got a better
>> understanding of it.  Will you take this through your tree?
>
> Yes, confusingly this patch was sent twice yesterday, once in this
> series and once separately.  AFAICT they're identical, so I'll add your
> R-b and add the patch to my pull request for 2.4-rc0.  Thanks,

Yes, these are identical, sorry for the confusion. btw what was the right 
to do with this patch?


>
> Alex
>
>>> ---
>>> Changes:
>>> v10:
>>> * new to the patchset
>>> ---
>>>   hw/vfio/common.c | 8 ++++++++
>>>   1 file changed, 8 insertions(+)
>>>
>>> diff --git a/hw/vfio/common.c b/hw/vfio/common.c
>>> index 89ef37b..8eacfd7 100644
>>> --- a/hw/vfio/common.c
>>> +++ b/hw/vfio/common.c
>>> @@ -772,11 +772,19 @@ static void vfio_disconnect_container(VFIOGroup *group)
>>>
>>>       if (QLIST_EMPTY(&container->group_list)) {
>>>           VFIOAddressSpace *space = container->space;
>>> +        VFIOGuestIOMMU *giommu, *tmp;
>>>
>>>           if (container->iommu_data.release) {
>>>               container->iommu_data.release(container);
>>>           }
>>>           QLIST_REMOVE(container, next);
>>> +
>>> +        QLIST_FOREACH_SAFE(giommu, &container->giommu_list, giommu_next, tmp) {
>>> +            memory_region_unregister_iommu_notifier(&giommu->n);
>>> +            QLIST_REMOVE(giommu, giommu_next);
>>> +            g_free(giommu);
>>> +        }
>>> +
>>>           trace_vfio_disconnect_container(container->fd);
>>>           close(container->fd);
>>>           g_free(container);
>>
>
>
>


-- 
Alexey