Hi Saeed, > On Nov 12, 2020, at 11:31 AM, Saeed Mahameed <sa...@kernel.org> wrote: > > On Tue, 2020-11-10 at 23:53 +0000, Patel, Vedang wrote: >>> With BTF formatted metadata it is up to the driver to advertise >>> whatever it can/want :) >>> so yes. >> >> I have a very basic question here. From what I understand about BTF, >> I can generate a header file (using bpftool?) containing the BTF data >> format provided by the driver. If so, how can I design an application >> which can work with multiple NICs drivers without recompilation? I am >> guessing there is some sort of “master list” of HW hints the drivers >> will agree upon? > > Hi Patel, as Jesper mentioned, some hints will be well defined in BTF > format, by name, size and type, e.g.: > > u32 hash32; > u16 vlan_tci; > u64 timestamp; > > etc.. > > if the driver reports only well known hints, a program compiled with > these can work in theory on any NIC that supports them. the BPF program > loader/verifier in the kernel can check compatibility before loading a > program on a NIC. > > now the question remains, What if different NICs/Drivers re-arrange > those fields differently? > this also can be solved by the BPF XDP program loader in the kernel at > rung time, it can re-arrange the meta data offsets according to the > current NIC directly in the byte code, but this is going to be a future > work. > Thanks for more info!
I have pulled in your changes and started modifying the igc driver. I will report back on how it goes. Thanks, Vedang
