From: Ciara Loftus Date: Fri, 11 Feb 2022 15:03:05 +0000 (+0000) Subject: doc: update libxdp usage in af_xdp guide X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=392e023d80344c598ccea0350bfee1640add9bdf;p=dpdk.git doc: update libxdp usage in af_xdp guide When libxdp is used, the LIBXDP_OBJECT_PATH environment variable must be set to the location of where libxdp placed its bpf object files. This is usually in /usr/local/lib/bpf or /usr/local/lib64/bpf. Failure to do so will result in the PMD not initialising correctly as the bpf program is not found. Document this requirement. Also, mention that the following logs which are generated on application launch can be ignored: libbpf: elf: skipping unrecognized data section(7) .xdp_run_config libbpf: elf: skipping unrecognized data section(8) xdp_metadata Signed-off-by: Ciara Loftus Acked-by: Ferruh Yigit --- diff --git a/doc/guides/nics/af_xdp.rst b/doc/guides/nics/af_xdp.rst index 3d8b70e3f8..ee1e146a9e 100644 --- a/doc/guides/nics/af_xdp.rst +++ b/doc/guides/nics/af_xdp.rst @@ -44,6 +44,9 @@ This is a Linux-specific PMD, thus the following prerequisites apply: * A Linux Kernel (version > v4.18) with XDP sockets configuration enabled; * Both libxdp >=v1.2.2 and libbpf libraries installed, or, libbpf <=v0.6.0 +* If using libxdp, it requires an environment variable called + LIBXDP_OBJECT_PATH to be set to the location of where libxdp placed its bpf + object files. This is usually in /usr/local/lib/bpf or /usr/local/lib64/bpf. * A Kernel bound interface to attach to; * For need_wakeup feature, it requires kernel version later than v5.3-rc1; * For PMD zero copy, it requires kernel version later than v5.4-rc1; @@ -150,4 +153,16 @@ Limitations as this is the maximum number of fds that can be sent through the IPC APIs as defined by RTE_MP_MAX_FD_NUM. +- **libxdp** + + When using the default program (ie. when the vdev arg 'xdp_prog' is not used), + the following logs will appear when an application is launched: + + .. code-block:: console + + libbpf: elf: skipping unrecognized data section(7) .xdp_run_config + libbpf: elf: skipping unrecognized data section(8) xdp_metadata + + These logs are not errors and can be ignored. + [1] https://lwn.net/Articles/837010/