RE: pmd_af_xdp: does net_af_xdp support different rx/tx queue configuration

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

> 
> Hello DPDK users,
> 
> Sorry to disturb.
> 
> I am currently testing net_af_xdp device.
> But I found the device configure always failed if I configure my rx queue != tx
> queue.
> In my project, I use pipeline mode, and require 1 rx and several tx queues.
> 
> Example:
> I run my app with paramter: "--no-pci --vdev
> net_af_xdp0,iface=ens12,queue_count=2 --vdev
> net_af_xdp1,iface=ens13,queue_count=2"
> And config 1 rx and 2 tx queue, it will setup failed by print: "Port0
> dev_configure = -22"
> 
> After checking some xdp docs, I found the rx and tx always bind to use,
> which connected to filling and completing ring.
> But I still want to comfirm this with you ? Could you please share your
> comments ?
> Thanks in advance.

Hi Christian,

Thanks for your question. Yes, at the moment this configuration is forbidden for the AF_XDP PMD. One socket is created for each pair of rx and tx queues.
However maybe this is an unnecessary restriction of the PMD. It is indeed possible to create a socket with either one rxq or one txq. I will put looking into the feasibility of enabling this in the PMD on my backlog.
In the meantime, one workaround you could try would be to create an even number of rxq and txqs but steer all traffic to the first rxq using some NIC filtering eg. tc.

Thanks,
Ciara

> 
> Br,
> Christian