Subject: Re: [PATCH v16 bpf-next 09/20] bpf: introduce BPF_F_XDP_MB flag in prog_flags loading the ebpf program

From: Lorenzo Bianconi <[email-masked]>
Date: Fri, 15 Oct 2021 15:29:18 +0200

> Lorenzo Bianconi <[email-masked]> writes:
> 
> > 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?
Should we just discard the XDP multi-buff in this case?

Lorenzo

> -Toke