Hi Janusz,
On 8/28/19 10:17 PM, Janusz Krzysztofik wrote:
We should avoid kernel panic when a intel_unmap() is called against
a non-existent domain.
Does that mean you suggest to replace
BUG_ON(!domain);
with something like
if (WARN_ON(!domain))
return;
and to not care of orphaned mappings left allocated? Is there a way to inform
users that their active DMA mappings are no longer valid and they shouldn't
call dma_unmap_*()?
But we shouldn't expect the IOMMU driver not
cleaning up the domain info when a device remove notification comes and
wait until all file descriptors being closed, right?
Shouldn't then the IOMMU driver take care of cleaning up resources still
allocated on device remove before it invalidates and forgets their pointers?
You are right. We need to wait until all allocated resources (iova and
mappings) to be released.
How about registering a callback for BUS_NOTIFY_UNBOUND_DRIVER, and
removing the domain info when the driver detachment completes?
Thanks,
Janusz
Best regards,
Baolu
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