Re: pyverbs test regression

[Edward Srouji <edwards@nvidia.com>]

On 11/4/2020 2:36 PM, Jason Gunthorpe wrote:
> On Wed, Nov 04, 2020 at 12:40:11PM +0200, Edward Srouji wrote:
>> On 11/4/2020 2:00 AM, Jason Gunthorpe wrote:
>>> On Tue, Nov 03, 2020 at 05:54:58PM -0600, Bob Pearson wrote:
>>>> Since 5.10 some of the pyverbs tests are skipping with the warning
>>>> 	"Device rxe_0 doesn't have net interface"
>>>>
>>>> These occur in tests/test_rdmacm.py. As far as I can tell the error occurs in
>>>>
>>>> RDMATestCase _add_gids_per_port after the following
>>>>
>>>> 	    if not os.path.exists('/sys/class/infiniband/{}/device/net/'.format(dev)):
>>>>                   self.args.append([dev, port, idx, None])
>>>>                   continue
>>>>
>>>> In fact there is no such path which means it never finds an ip_addr for the device.
>>> That isn't an acceptable way to find netdevs for a RDMA device..
>>>
>>> This test is really buggy, that is not an acceptable way to find the
>>> netdev for a RDMA device. Looks like it is some hacky way to read the
>>> gid table? It should just read the gid table.. Edward?
>> GID table is not the reason. We need the netdev in order to get the IP
>> address of the interface.
> The GID table has a list of all the IP addresses of the IB device, and
> all the netdevs that provide it

Then how can you get the IP address via verbs API(s)? AFAIK, the 
gid_entry does not hold the IP addresses, you can only get the subnet 
prefix, don't you?

>
>>>> Did something change here? Do other RDMA devices have /sys/class/infiniband/XXX/device/net?
>>> Yes, some will
>> Nothing really changed in this area lately (in pyverbs / rdma-core tests).
>>
>> RXE can also have a netdev here if it's linked to one. E.g. by doing "rdma
>> link add <rxe_devname> type rxe netdev <net_devname>"
> No it can't, this is the "parent" device and ib_device can never be a
> parent of a netdev. rxe should have no parent.
>
> Jason
Edward