On Thu, Sep 25, 2025 at 12:39 PM +02, Lorenzo Bianconi wrote: >> On Thu, Sep 25, 2025 at 11:30 AM +02, Lorenzo Bianconi wrote: >> > Introduce bpf_xdp_metadata_rx_checksum() kfunc in order to load the HW >> > RX cheksum results in the eBPF program binded to the NIC. >> > Implement xmo_rx_checksum callback for veth and ice drivers. >> >> What are going to do with HW RX checksum once XDP prog can access it? > > I guess there are multiple use-cases for bpf_xdp_metadata_rx_checksum() > kfunc. The first the I have in mind is when packets are received by an af_xdp > application. In this case I think we currently do not have any way to check if > the packet checksum is correct, right? > I think Jesper has other use-cases in mind, I will let him comment > here.
Can you share more details on what the AF_XDP application would that info? Regarding the use cases that Jesper is trying to unlock, as things stand we don't have a way, or an agreement on how to inject/propagate even the already existing NIC hints back into the network stack. Hence my question - why do we want to expose another NIC hint to XDP that we can't consume in any useful way yet? Shouldn't we first figure out how we're planning to re-inject that info into the stack?
