Re: [PATCH] Xen/PCI: correct notifier used for device removal

[Jan Beulich]

>>> On 01.02.16 at 13:01, <david.vrabel@xxxxxxxxxx> wrote:
> On 01/02/16 11:58, Jan Beulich wrote:
>> Commit 599bad38cf added BUS_NOTIFY_REMOVED_DEVICE in order to allow
>> avoiding removal of IOMMU mappings before the driver actually got
>> unbound from the device. Naturally we should be using this too.
> 
> Because otherwise...?  What happens if we don't make this change?
> 
> Removing IOMMU mappings for a device when the driver is still bound to
> the device looks wrong to me. Surely the device is still active and may
> still be performing DMA at this point?

Exactly - you answered your own question (as does the commit
referred to).

Jan