Re: [dpdk-dev] [PATCH v2] net/af_xdp: use bpf link for XDP programs

[Ferruh Yigit <ferruh.yigit@intel.com>]

On 10/22/2021 11:42 AM, Ciara Loftus wrote:
> Since v0.4.0, if the underlying kernel supports it, libbpf uses 'bpf link'
> to manage the programs on the interfaces of the xsks. This has two
> repercussions for the PMD.
> 
> 1. In the case where the PMD asks libbpf to load the default XDP program,
> the PMD no longer needs to remove it on teardown. This is because bpf link
> handles the unloading under the hood.
> 2. In the case where the PMD loads a custom program, libbpf expects this
> program to be linked via bpf link prior to creating the socket.
> 
> This patch introduces probes for the libbpf version and kernel support
> for bpf link and orchestrates the loading and unloading of
> programs according to the capabilities of the kernel and libbpf. The
> libbpf version is checked with meson and pkg-config. The probe for
> kernel support mirrors how it is implemented in libbpf. A bpf_link is
> created and looked up on loopback device. If successful, bpf_link will be
> used for the AF_XDP netdev.
> 
> Signed-off-by: Ciara Loftus <ciara.loftus@intel.com>
> Signed-off-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>

Applied to dpdk-next-net/main, thanks.