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

[David Gibson]

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 <address@hidden>

Reviewed-by: David Gibson <address@hidden>

Alex,

I think this is correct, but you've probably got a better
understanding of it.  Will you take this through your tree?


> ---
> 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);

-- 
David Gibson                    | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au  | minimalist, thank you.  NOT _the_ _other_
                                | _way_ _around_!
http://www.ozlabs.org/~dgibson

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