Re: XDP_REDIRECT with xsks_map and dev_map

On Tue, Jun 2, 2020 at 9:31 PM Toke Høiland-Jørgensen <[email protected]> wrote:
>
> maharishi bhargava <[email protected]> writes:
>
> > On Tue 2 Jun, 2020, 14:31 Toke Høiland-Jørgensen, <[email protected]> wrote:
> >>
> >> maharishi bhargava <[email protected]> writes:
> >>
> >> > Hi, in my XDP program, I want to redirect some packets using AF_XDP
> >> > and redirect other packets directly from driver space.
> >> > Redirection through AF_XDP works fine, but redirection through dev map
> >> > stops after some packets are processed.
> >>
> >> Do you mean it stops even if you are *only* redirecting to a devmap, or
> >> if you are first redirecting a few packets to AF_XDP, then to devmap?
> >>
> >> Also, which driver(s) are the physical NICs you're redirecting to/from
> >> using, and which kernel version are you on?
> >>
> >> -Toke
> >
> >
> >
> > Currently, I'm trying to redirect packets only using devmap. But also
> > have code for redirection using AF_XDP(only when a given condition is
> > satisfied). A DPDK program is running in userspace which will receive
> > packets from AF_XDP.
>
> Right, so it's just devmap redirect that breaks. What do you mean
> 'redirection stops', exactly? How are you seeing this? Does xdp_monitor
> (from samples/bpf) report any exceptions?
>
> -Toke
>
So, In my setup, there are three systems, Let's Assume A, B, C. System
B is acting as a forwarder between A and C. So I can see the number of
packets received at system C. To be specific, only 1024 packets are
received. If I remove the xsks_map part from the code and don't run
DPDK in userspace. This problem does not occur. Also if I forward all
the packets using AF_XDP, there is no such issue.

- Maharishi