Re: Error running AF_XDP sample application

[Konrad Djimeli <kdjimeli@igalia.com>]

On 2018-08-10 11:58, Konrad Djimeli wrote:
> On 2018-08-10 03:51, Jakub Kicinski wrote:
>> On Thu, 09 Aug 2018 18:18:08 +0200, kdjimeli wrote:
>>> Hello,
>>>
>>> I have been trying to test a sample AF_XDP program, but I have been
>>> experiencing some issues.
>>> After building the sample code
>>> https://github.com/torvalds/linux/tree/master/samples/bpf,
>>> when running the xdpsock binary, I get the errors
>>> "libbpf: failed to create map (name: 'xsks_map'): Invalid argument"
>>> "libbpf: failed to load object './xdpsock_kern.o"
>>>
>>> I tried to figure out the cause of the error but all I know is that it
>>> occurs at line 910 with the function
>>> call "bpf_prog_load_xattr(&prog_load_attr, &obj, &prog_fd)".
>>>
>>> Please I would like to inquire what could be a possible for this error.
>>
>> which kernel version are you running?
> 
> My kernel version is 4.18.0-rc8+. I cloned it from
> https://github.com/torvalds/linux before building a running.
> 
> My commit head(git show-ref --head) is at
> 1236568ee3cbb0d3ac62d0074a29b97ecf34cbbc HEAD
> 1236568ee3cbb0d3ac62d0074a29b97ecf34cbbc refs/heads/master
> 1236568ee3cbb0d3ac62d0074a29b97ecf34cbbc refs/remotes/origin/HEAD
> 1236568ee3cbb0d3ac62d0074a29b97ecf34cbbc refs/remotes/origin/master
> ...
> 
> 
> I also applied the patch https://patchwork.ozlabs.org/patch/949884/
> (samples: bpf: convert xdpsock_user.c to libbpf ), as the error was
> initially in the form show below:
>   "failed to create a map: 22 Invalid argument"
>   "ERROR: load_bpf_file"
> 
> Thanks
> Konrad

Also other sample applications that make use of other bpf maps, such as
BPF_MAP_TYPE_CPUMAP in xdp_redirect_cpu work fine. But the application
with BPF_MAP_TYPE_XSKMAP fails producing the error mentioned above.

Thanks
Konrad