dpdk-testpmd on XDP

[Stephen Hemminger]

On Wed, 20 Mar 2024 08:22:05 +0100
Alessio Igor Bogani <alessio.bogani at elettra.eu> wrote:

> Stephen,
> 
> Thanks for your reply!
> 
> On Tue, 19 Mar 2024 at 17:07, Stephen Hemminger
> <stephen at networkplumber.org> wrote:
> >
> > On Tue, 19 Mar 2024 11:48:53 +0100
> > Alessio Igor Bogani <alessio.bogani at elettra.eu> wrote:
> >  
> > > The only suspicious part in the output of the dpdk-testpmd utility is:
> > > [...]
> > > libxdp: XDP flag not supported by libxdp.
> > > libbpf: prog 'xdp_dispatcher': BPF program load failed: Invalid argument
> > > libbpf: prog 'xdp_dispatcher': -- BEGIN PROG LOAD LOG --
> > > Validating prog0() func#1...
> > > btf_vmlinux is malformed
> > > Arg#0 type PTR in prog0() is not supported yet.
> > > processed 0 insns (limit 1000000) max_states_per_insn 0 total_states 0
> > > peak_states 0 mark_read 0
> > > -- END PROG LOAD LOG --
> > > libbpf: failed to load program 'xdp_dispatcher'
> > > libbpf: failed to load object 'xdp-dispatcher.o'
> > > libxdp: Failed to load dispatcher: Invalid argument
> > > libxdp: Falling back to loading single prog without dispatcher
> > > [...]  
> >
> > What distribution and kernel version?  
> 
> Custom distribution (Yocto Kirkstone) using 5.10.184.All parts
> (kernel, DPDK, libbpf, xdp-tools) are built (cross-compiled) from
> source.

Then you need to build bpf tools from the same kernel directory and use
them in the DPDK build.  The problem is that DPDK build uses pkg-config
to get the XDP and BPF library versions. That probably won't work as expected
with this type of Yocto build.