net/mlx5e: XDP fast RX drop bpf programs support
Add support for the BPF_PROG_TYPE_PHYS_DEV hook in mlx5e driver. When XDP is on we make sure to change channels RQs type to MLX5_WQ_TYPE_LINKED_LIST rather than "striding RQ" type to ensure "page per packet". On XDP set, we fail if HW LRO is set and request from user to turn it off. Since on ConnectX4-LX HW LRO is always on by default, this will be annoying, but we prefer not to enforce LRO off from XDP set function. Full channels reset (close/open) is required only when setting XDP on/off. When XDP set is called just to exchange programs, we will update each RQ xdp program on the fly and for synchronization with current data path RX activity of that RQ, we temporally disable that RQ and ensure RX path is not running, quickly update and re-enable that RQ, for that we do: - rq.state = disabled - napi_synnchronize - xchg(rq->xdp_prg) - rq.state = enabled - napi_schedule // Just in case we've missed an IRQ Packet rate performance testing was done with pktgen 64B packets and on TX side and, TC drop action on RX side compared to XDP fast drop. CPU: Intel(R) Xeon(R) CPU E5-2680 v3 @ 2.50GHz Comparison is done between: 1. Baseline, Before this patch with TC drop action 2. This patch with TC drop action 3. This patch with XDP RX fast drop RX Cores Baseline(TC drop) TC drop XDP fast Drop -------------------------------------------------------------- 1 5.3Mpps 5.3Mpps 16.5Mpps 2 10.2Mpps 10.2Mpps 31.3Mpps 4 20.5Mpps 19.9Mpps 36.3Mpps* *My xmitter was limited to 36.3Mpps, so it is the bottleneck. It seems that receive side can handle more. Signed-off-by:Rana Shahout <ranas@mellanox.com> Signed-off-by: