RE: [dpdk-users] net_af_xdp start failed with can't get next link

["Loftus, Ciara" <ciara.loftus@intel.com>]

> 
> Hello,
> 
> I try to use af_xdp of DPDK 19.11, but start failed with testpmd. Here is the
> log prints, could you please give suggestion for this error ? Thanks in
> advance!
> 
> ------
> [root@gc bin]$ ./testpmd -l 1,2,3 -n 4 --log-level=pmd.net.af_xdp:info --no-
> pci --vdev net_af_xdp,iface=ens12,start_queue=0,queue_count=3 -- -i --
> rxq=3 --txq=3
> EAL: Detected 16 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...
> rte_pmd_af_xdp_probe(): Initializing pmd_af_xdp for net_af_xdp
> init_internals(): Zero copy between umem and mbuf enabled.
> Interactive-mode selected
> testpmd: create a new mbuf pool <mbuf_pool_socket_0>: n=163456,
> size=2176, socket=0
> testpmd: preferred mempool ops selected: ring_mp_mc
> 
> Warning! port-topology=paired and odd forward ports number, the last port
> will pair with itself.
> 
> Configuring Port 0 (socket 0)
> eth_rx_queue_setup(): Set up rx queue, rx queue id: 0, xsk queue id: 0
> libbpf: can't get next link: Invalid argument
> eth_rx_queue_setup(): Set up rx queue, rx queue id: 1, xsk queue id: 1
> libbpf: can't get next link: Invalid argument
> eth_rx_queue_setup(): Set up rx queue, rx queue id: 2, xsk queue id: 2
> libbpf: can't get next link: Invalid argument
> Port 0: FA:0C:B1:0F:DF:01

Apologies for missing this email last week. Somehow it only reached my inbox today.
I believe we got to the root of the problem here:
https://github.com/xdp-project/xdp-tutorial/issues/255#issuecomment-953863354
Just including the resolution in this thread too, in case others find the same issue.

Thanks,
Ciara

> ------
> 
> My test env:
> DPDK: stable 19.11.6
> libbpf: git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git
> OS：Centos 7.9 + kernel 5.4.155-1.el7.elrepo.x86_64
> 
> 
> Br,
> Christian