[dpdk-users] "eth_i40e_dev_init(): Failed to init adminq: -66" problem

[Sunghyuk Kay]

Hi all,
I'm setting DPDK on our hardware to do some experiment, but suffering from .

I was trying to use DPDK on Ubuntu 18.04 with Intel XL710 Ethernet Adapter
with igb_uio driver. I've compiled DPDK from source, and bound the driver
to NIC.
But when I run `testpmd` application, it returns an error like this.

```
$ sudo ./build/app/testpmd
EAL: Detected 128 lcore(s)
EAL: Detected 1 NUMA nodes
EAL: Multi-process socket /var/run/dpdk/rte/mp_socket
EAL: Selected IOVA mode 'PA'
EAL: No available hugepages reported in hugepages-1048576kB
EAL: Probing VFIO support...
EAL: PCI device 0000:81:00.0 on NUMA socket 0
EAL:   probe driver: 8086:1583 net_i40e
eth_i40e_dev_init(): Failed to init adminq: -66
EAL: ethdev initialisation failedEAL: Requested device 0000:81:00.0 cannot
be used
EAL: PCI device 0000:81:00.1 on NUMA socket 0
EAL:   probe driver: 8086:1583 net_i40e
eth_i40e_dev_init(): Failed to init adminq: -66
EAL: ethdev initialisation failedEAL: Requested device 0000:81:00.1 cannot
be used
EAL: PCI device 0000:c4:00.0 on NUMA socket 0
EAL:   probe driver: 8086:1533 net_e1000_igb
EAL: PCI device 0000:c5:00.0 on NUMA socket 0
EAL:   probe driver: 8086:1533 net_e1000_igb
testpmd: No probed ethernet devices
testpmd: create a new mbuf pool <mbuf_pool_socket_0>: n=1163456, size=2176,
socket=0
testpmd: preferred mempool ops selected: ring_mp_mc
Done
No commandline core given, start packet forwarding
io packet forwarding - ports=0 - cores=0 - streams=0 - NUMA support
enabled, MP allocation mode: native

  io packet forwarding packets/burst=32
  nb forwarding cores=1 - nb forwarding ports=0
Press enter to exit

Telling cores to stop...
Waiting for lcores to finish...

  +++++++++++++++ Accumulated forward statistics for all
ports+++++++++++++++
  RX-packets: 0              RX-dropped: 0             RX-total: 0
  TX-packets: 0              TX-dropped: 0             TX-total: 0

++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

Done.

Bye...
```
I tried to find what return code -66 from adminq means, but I couldn't find
it.
Some say this might have to do with Intel IOMMU pass-through, but I'm not
sure that's the case.

Has anyone had this issue before? Maybe some tip on this issue would be
very helpful.

Thank you,
Sunghyuk