Error running AF_XDP sample application

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.


Thanks
Konrad

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?

On 2018-08-10 03:51, Jakub Kicinski wrote:

On Thu, 09 Aug 2018 18:18:08 +0200, kdjimeli wrote:

quoted

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

On 2018-08-10 11:58, Konrad Djimeli wrote:

On 2018-08-10 03:51, Jakub Kicinski wrote:

quoted

On Thu, 09 Aug 2018 18:18:08 +0200, kdjimeli wrote:

quoted

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

Den fre 10 aug. 2018 kl 15:23 skrev Konrad Djimeli [off-list ref]:

On 2018-08-10 11:58, Konrad Djimeli wrote:

quoted

On 2018-08-10 03:51, Jakub Kicinski wrote:

quoted

On Thu, 09 Aug 2018 18:18:08 +0200, kdjimeli wrote:

quoted

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

Thanks for taking AF_XDP for a spin!

Before I start digging into details; Do you have CONFIG_XDP_SOCKETS=y
in your config? :-)


Björn

On 2018-08-10 17:45, Björn Töpel wrote:
Thanks for taking AF_XDP for a spin!

Thanks, I am actually an Igalia Coding Experience participant working
remotely from Cameroon in Africa and I am working on making use of
AF_XDP within Snabb. I am currently trying to familiarize myself with
XDP and AF_XDP, I also hope to make contributions to the
development/implementation of AF_XDP.

Before I start digging into details; Do you have CONFIG_XDP_SOCKETS=y
in your config? :-)

Yay!, setting CONFIG_XDP_SOCKETS=y in my config resolved every issue,
and it now works fine.

Björn

Konrad