On Mon, 8 Mar 2021 12:06:58 +0100 Lorenzo Bianconi <lore...@kernel.org> wrote:
> We want to change the current ndo_xdp_xmit drop semantics because > it will allow us to implement better queue overflow handling. > This is working towards the larger goal of a XDP TX queue-hook. > Move XDP_REDIRECT error path handling from each XDP ethernet driver to > devmap code. According to the new APIs, the driver running the > ndo_xdp_xmit pointer, will break tx loop whenever the hw reports a tx > error and it will just return to devmap caller the number of successfully > transmitted frames. It will be devmap responsability to free dropped > frames. > Move each XDP ndo_xdp_xmit capable driver to the new APIs: > - veth > - virtio-net > - mvneta > - mvpp2 > - socionext > - amazon ena > - bnxt > - freescale (dpaa2, dpaa) > - xen-frontend > - qede > - ice > - igb > - ixgbe > - i40e > - mlx5 > - ti (cpsw, cpsw-new) > - tun > - sfc > > Acked-by: Edward Cree <ecree.xil...@gmail.com> > Reviewed-by: Ioana Ciornei <ioana.cior...@nxp.com> > Reviewed-by: Ilias Apalodimas <ilias.apalodi...@linaro.org> > Signed-off-by: Lorenzo Bianconi <lore...@kernel.org> > --- > More details about the new ndo_xdp_xmit design can be found here [0]. > > [0] > https://github.com/xdp-project/xdp-project/blob/master/areas/core/redesign01_ndo_xdp_xmit.org > > Changes since v2: > - drop wrong comment in ena driver > - simplify drop condition using unlikey in the for condition of devmap code > - rebase on top of bpf-next > - collect acked-by/reviewed-by > > Changes since v1: > - rebase on top of bpf-next > - add driver maintainers in cc > - add Edward's ack > --- > drivers/net/ethernet/amazon/ena/ena_netdev.c | 21 ++++++------- > drivers/net/ethernet/broadcom/bnxt/bnxt_xdp.c | 20 +++++-------- > .../net/ethernet/freescale/dpaa/dpaa_eth.c | 12 ++++---- > .../net/ethernet/freescale/dpaa2/dpaa2-eth.c | 2 -- > drivers/net/ethernet/intel/i40e/i40e_txrx.c | 15 +++++----- > drivers/net/ethernet/intel/ice/ice_txrx.c | 15 +++++----- > drivers/net/ethernet/intel/igb/igb_main.c | 11 ++++--- > drivers/net/ethernet/intel/ixgbe/ixgbe_main.c | 11 ++++--- > drivers/net/ethernet/marvell/mvneta.c | 13 ++++---- > .../net/ethernet/marvell/mvpp2/mvpp2_main.c | 13 ++++---- > .../net/ethernet/mellanox/mlx5/core/en/xdp.c | 15 ++++------ > drivers/net/ethernet/qlogic/qede/qede_fp.c | 19 +++++------- > drivers/net/ethernet/sfc/tx.c | 15 +--------- > drivers/net/ethernet/socionext/netsec.c | 16 +++++----- > drivers/net/ethernet/ti/cpsw.c | 14 ++++----- > drivers/net/ethernet/ti/cpsw_new.c | 14 ++++----- > drivers/net/ethernet/ti/cpsw_priv.c | 11 +++---- > drivers/net/tun.c | 15 ++++++---- > drivers/net/veth.c | 28 +++++++++-------- > drivers/net/virtio_net.c | 25 ++++++++-------- > drivers/net/xen-netfront.c | 18 +++++------ > kernel/bpf/devmap.c | 30 ++++++++----------- > 22 files changed, 153 insertions(+), 200 deletions(-) Acked-by: Jesper Dangaard Brouer <bro...@redhat.com> Acking core changes to bpf/devmap.c (kept below). I've only skimmed the driver changes. > diff --git a/kernel/bpf/devmap.c b/kernel/bpf/devmap.c > index 85d9d1b72a33..d6330bbe1209 100644 > --- a/kernel/bpf/devmap.c > +++ b/kernel/bpf/devmap.c > @@ -330,7 +330,7 @@ bool dev_map_can_have_prog(struct bpf_map *map) > static void bq_xmit_all(struct xdp_dev_bulk_queue *bq, u32 flags) > { > struct net_device *dev = bq->dev; > - int sent = 0, drops = 0, err = 0; > + int sent = 0, err = 0; > int i; > > if (unlikely(!bq->count)) > @@ -344,29 +344,23 @@ static void bq_xmit_all(struct xdp_dev_bulk_queue *bq, > u32 flags) > > sent = dev->netdev_ops->ndo_xdp_xmit(dev, bq->count, bq->q, flags); > if (sent < 0) { > + /* If ndo_xdp_xmit fails with an errno, no frames have > + * been xmit'ed. > + */ > err = sent; > sent = 0; > - goto error; > } > - drops = bq->count - sent; > -out: > - bq->count = 0; > > - trace_xdp_devmap_xmit(bq->dev_rx, dev, sent, drops, err); > - bq->dev_rx = NULL; > - __list_del_clearprev(&bq->flush_node); > - return; > -error: > - /* If ndo_xdp_xmit fails with an errno, no frames have been > - * xmit'ed and it's our responsibility to them free all. > + /* If not all frames have been transmitted, it is our > + * responsibility to free them > */ > - for (i = 0; i < bq->count; i++) { > - struct xdp_frame *xdpf = bq->q[i]; > + for (i = sent; unlikely(i < bq->count); i++) > + xdp_return_frame_rx_napi(bq->q[i]); > > - xdp_return_frame_rx_napi(xdpf); > - drops++; > - } > - goto out; > + trace_xdp_devmap_xmit(bq->dev_rx, dev, sent, bq->count - sent, err); > + bq->dev_rx = NULL; > + bq->count = 0; > + __list_del_clearprev(&bq->flush_node); > } > > /* __dev_flush is called from xdp_do_flush() which _must_ be signaled -- Best regards, Jesper Dangaard Brouer MSc.CS, Principal Kernel Engineer at Red Hat LinkedIn: http://www.linkedin.com/in/brouer
