[PATCH] net/tap: Modified TAP BPF program as per the Kernel-version upgrade requirements.

[Stephen Hemminger]

On Fri, 12 Jan 2024 19:18:21 +0530
madhuker.mythri at oracle.com wrote:

> +struct  {
> +	__uint(type,       BPF_MAP_TYPE_HASH);
> +	__type(key,  __u32);
> +	__type(value,     struct rss_key);
> +	__uint(max_entries,      256);
> +} map_keys SEC(".maps");
>  

Overall this patch is a big step forward in getting TAP BPF going again.
But using the new BTF maps won't work with how the tap device is
loading the BPF program. Getting BTF to work requires more steps and
is best done by using libbpf. With this part of your version current
kernels will give type mismatch in verifier since the type information
for map_keys is not loaded.

See my followon RFC for what libbpf integration looks like.
Ends up being a deeper rewrite.