Lorenzo Bianconi [off-list ref] writes:

quoted

Lorenzo Bianconi [off-list ref] writes:

quoted

Introduce BPF_F_XDP_MB and the related field in bpf_prog_aux in order to
notify the driver the loaded program support xdp multi-buffer.

We should also add some restrictions in the BPF core. In particular,
tail call, cpumap and devmap maps should not be able to mix multi-buf
and non-multibuf programs.

ack. How can we detect if a cpumap or a devmap is running in XDP multi-buff
mode in order to reject loading the legacy XDP program?

I was hoping we could copy the same mechanism that tail call maps to
ensure that callers and callees are the same type. And amend that to
also consider the xdp_mb flag while we're at it :)

Should we just discard the XDP multi-buff in this case?

If I'm right in the above, we won't have to because the verifier can
ensure that the program types match...

-Toke