[dpdk-dev] vfio: failed to select IOMMU type

[Andrew Rybchenko]

On 04/04/2017 06:52 PM, Burakov, Anatoly wrote:
> Hi Andrew,
>
>> I think a key to the main problem is the same IOMMU group used for both PCI functions.
>> It tries to set IOMMU type using the same file descriptor twice. The second set is dummy, since the same value is set, but still fails, I guess, because it is already in use.
>> See logs with debug enabled and few extra logs below:
> Yes you're right. Specifically, eal_vfio.c:vfio_setup_device() at line  311 (where we check for number of groups) - the code always assumes that one
> active group means we've just initialized a new group, which may not necessarily be the case if there's more than one device per group.
>
> Alejandro, please correct me if I'm wrong, but I think this raises another issue: vfio_release_device() seems to attempt to close group fd unconditionally,
> which is probably a bad idea if there are more than one device per group.

If it is true, please, care about it.

> Would you be so kind to come up with a patch to fix this oversight, or should I do it? :)

Please, take a look at http://dpdk.org/dev/patchwork/patch/23202/
Basically it just moves IOMMU type set under previous container-not-set 
condition.
Also my testing is very restricted, no hotplug, no different IOMMU groups.

Andrew.