Re: [PATCH bpf-next v2] bpftool: specify XDP Hints ifname when loading program

[Quentin Monnet]

2023-05-17 18:01 UTC+0200 ~ Larysa Zaremba <larysa.zaremba@xxxxxxxxx>
> Add ability to specify a network interface used to resolve
> XDP Hints kfuncs when loading program through bpftool.
> 
> Usage:
>   bpftool prog load [...] xdpmeta_dev <ifname>
> 
> Writing just 'dev <ifname>' instead of 'xdpmeta_dev' is a very probable
> mistake that results in not very descriptive errors,
> so 'bpftool prog load [...] dev <ifname>' syntax becomes deprecated,
> followed by 'bpftool map create [...] dev <ifname>' for consistency.
> 
> Now, to offload program, execute:
>   bpftool prog load [...] offload_dev <ifname>
> 
> To offload map:
>   bpftool map create [...] offload_dev <ifname>
> 
> 'dev <ifname>' still performs offloading in the commands above, but now
> triggers a warning and is excluded from bash completion.
> 
> 'xdpmeta_dev' and 'offload_dev' are mutually exclusive options, because
> 'xdpmeta_dev' basically makes a program device-bound without loading it
> onto the said device. For now, offloaded programs cannot use XDP hints [0],
> but if this changes, using 'offload_dev <ifname>' should cover this case.
> 
> [0] https://lore.kernel.org/bpf/a5a636cc-5b03-686f-4be0-000383b05cfc@xxxxxxxxx
> 
> Signed-off-by: Larysa Zaremba <larysa.zaremba@xxxxxxxxx>
Reviewed-by: Quentin Monnet <quentin@xxxxxxxxxxxxx>

Thanks!