On Fri, 21 Dec 2018 14:22:23 +0100 Domagoj Pintaric <domagoj.pinta...@sartura.hr> wrote:
> Add initial mvneta XDP support for hardware buffer management enabled > devices only. Hi Domagoj, I would really appreciate if we could coordinate our work on the mvneta driver. Ilias (Cc'ed) and I are also working on adding XDP support for this driver, although this is the software-buffer side of the driver we have functioning now. You can directly follow our progress here: [1][2] [1] https://github.com/xdp-project/xdp-project/blob/master/areas/arm64/board_espressobin04_bench_xdp.org [2] https://github.com/apalos/bpf-next/commits/mvneta_04_page_pool_recycle_xdp You XDP-setup function is actually more correct that ours[3], as you handle BPF per queue (which we were planning to fix before upstreaming). That said, adding XDP_DROP is easy, but I want to see more of the XDP features/actions added, as those require a lot more work. I always worry that a driver will stop at just XDP_DROP, so what are your plans for adding the harder features? Even-thought XDP_DROP looks easy in this patch, then you are actually doing some wrong, as XDP can also modify frames before doing XDP_PASS, and (1) you have non-standard-head room (MVNETA_MH_SIZE + NET_SKB_PAD), (2) and you don't handle if XDP changed the xdp.data header pointer, and (3) you backing memory either comes from page-fragments or kmalloc which also goes against the XDP memory requirements. [3] https://github.com/apalos/bpf-next/commit/4b567e74552d3cdf55 -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer
