On Fri, Jun 14, 2024 at 2:39 PM Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> wrote: > > This patch implement the logic of bind/unbind xsk pool to sq and rq. > > Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx> > --- > drivers/net/virtio_net.c | 201 ++++++++++++++++++++++++++++++++++++++- > 1 file changed, 200 insertions(+), 1 deletion(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 88ab9ea1646f..35fd8bca7fcf 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -26,6 +26,7 @@ > #include <net/netdev_rx_queue.h> > #include <net/netdev_queues.h> > #include <uapi/linux/virtio_ring.h> > +#include <net/xdp_sock_drv.h> > > static int napi_weight = NAPI_POLL_WEIGHT; > module_param(napi_weight, int, 0444); > @@ -57,6 +58,8 @@ DECLARE_EWMA(pkt_len, 0, 64) > > #define VIRTNET_DRIVER_VERSION "1.0.0" > > +static struct virtio_net_hdr_mrg_rxbuf xsk_hdr; Does this mean AF_XDP only supports virtio_net_hdr_mrg_rxbuf but not others? > + > static const unsigned long guest_offloads[] = { > VIRTIO_NET_F_GUEST_TSO4, > VIRTIO_NET_F_GUEST_TSO6, > @@ -321,6 +324,12 @@ struct send_queue { > bool premapped; > > struct virtnet_sq_dma_info dmainfo; > + > + struct { > + struct xsk_buff_pool *pool; > + > + dma_addr_t hdr_dma_address; > + } xsk; > }; > > /* Internal representation of a receive virtqueue */ > @@ -372,6 +381,13 @@ struct receive_queue { > > /* Record the last dma info to free after new pages is allocated. */ > struct virtnet_rq_dma *last_dma; > + > + struct { > + struct xsk_buff_pool *pool; > + > + /* xdp rxq used by xsk */ > + struct xdp_rxq_info xdp_rxq; > + } xsk; > }; > > /* This structure can contain rss message with maximum settings for indirection table and keysize > @@ -695,7 +711,7 @@ static void virtnet_sq_free_dma_meta(struct send_queue *sq) > /* This function must be called immediately after creating the vq, or after vq > * reset, and before adding any buffers to it. > */ > -static __maybe_unused int virtnet_sq_set_premapped(struct send_queue *sq, bool premapped) > +static int virtnet_sq_set_premapped(struct send_queue *sq, bool premapped) > { > if (premapped) { > int r; > @@ -5177,6 +5193,187 @@ static int virtnet_restore_guest_offloads(struct virtnet_info *vi) > return virtnet_set_guest_offloads(vi, offloads); > } > > +static int virtnet_rq_bind_xsk_pool(struct virtnet_info *vi, struct receive_queue *rq, > + struct xsk_buff_pool *pool) > +{ > + int err, qindex; > + > + qindex = rq - vi->rq; > + > + if (pool) { > + err = xdp_rxq_info_reg(&rq->xsk.xdp_rxq, vi->dev, qindex, rq->napi.napi_id); > + if (err < 0) > + return err; > + > + err = xdp_rxq_info_reg_mem_model(&rq->xsk.xdp_rxq, > + MEM_TYPE_XSK_BUFF_POOL, NULL); > + if (err < 0) { > + xdp_rxq_info_unreg(&rq->xsk.xdp_rxq); > + return err; > + } > + > + xsk_pool_set_rxq_info(pool, &rq->xsk.xdp_rxq); > + } > + > + virtnet_rx_pause(vi, rq); > + > + err = virtqueue_reset(rq->vq, virtnet_rq_unmap_free_buf); > + if (err) { > + netdev_err(vi->dev, "reset rx fail: rx queue index: %d err: %d\n", qindex, err); > + > + pool = NULL; > + } > + > + if (!pool) > + xdp_rxq_info_unreg(&rq->xsk.xdp_rxq); Let's use err label instead of duplicating xdp_rxq_info_unreg() here? > + > + rq->xsk.pool = pool; > + > + virtnet_rx_resume(vi, rq); > + > + return err; > +} > + > +static int virtnet_sq_bind_xsk_pool(struct virtnet_info *vi, > + struct send_queue *sq, > + struct xsk_buff_pool *pool) > +{ > + int err, qindex; > + > + qindex = sq - vi->sq; > + > + virtnet_tx_pause(vi, sq); > + > + err = virtqueue_reset(sq->vq, virtnet_sq_free_unused_buf); > + if (err) > + netdev_err(vi->dev, "reset tx fail: tx queue index: %d err: %d\n", qindex, err); > + else > + err = virtnet_sq_set_premapped(sq, !!pool); > + > + if (err) > + pool = NULL; > + > + sq->xsk.pool = pool; > + > + virtnet_tx_resume(vi, sq); > + > + return err; > +} > + > +static int virtnet_xsk_pool_enable(struct net_device *dev, > + struct xsk_buff_pool *pool, > + u16 qid) > +{ > + struct virtnet_info *vi = netdev_priv(dev); > + struct receive_queue *rq; > + struct send_queue *sq; > + struct device *dma_dev; > + dma_addr_t hdr_dma; > + int err; > + > + /* In big_packets mode, xdp cannot work, so there is no need to > + * initialize xsk of rq. > + * > + * Support for small mode firstly. This comment is kind of confusing, I think mergeable mode is also supported. If it's true, we can simply remove it. > + */ > + if (vi->big_packets) > + return -ENOENT; > + > + if (qid >= vi->curr_queue_pairs) > + return -EINVAL; > + > + sq = &vi->sq[qid]; > + rq = &vi->rq[qid]; > + > + /* xsk tx zerocopy depend on the tx napi. > + * > + * All xsk packets are actually consumed and sent out from the xsk tx > + * queue under the tx napi mechanism. > + */ > + if (!sq->napi.weight) > + return -EPERM; > + > + /* For the xsk, the tx and rx should have the same device. But > + * vq->dma_dev allows every vq has the respective dma dev. So I check > + * the dma dev of vq and sq is the same dev. > + */ > + if (virtqueue_dma_dev(rq->vq) != virtqueue_dma_dev(sq->vq)) > + return -EPERM; I don't understand how a different DMA device matters here. It looks like the code is using per virtqueue DMA below. > + > + dma_dev = virtqueue_dma_dev(rq->vq); > + if (!dma_dev) > + return -EPERM; > + > + hdr_dma = dma_map_single(dma_dev, &xsk_hdr, vi->hdr_len, DMA_TO_DEVICE); > + if (dma_mapping_error(dma_dev, hdr_dma)) > + return -ENOMEM; > + > + err = xsk_pool_dma_map(pool, dma_dev, 0); > + if (err) > + goto err_xsk_map; > + > + err = virtnet_rq_bind_xsk_pool(vi, rq, pool); > + if (err) > + goto err_rq; > + > + err = virtnet_sq_bind_xsk_pool(vi, sq, pool); > + if (err) > + goto err_sq; > + > + /* Now, we do not support tx offset, so all the tx virtnet hdr is zero. > + * So all the tx packets can share a single hdr. > + */ > + sq->xsk.hdr_dma_address = hdr_dma; > + > + return 0; > + > +err_sq: > + virtnet_rq_bind_xsk_pool(vi, rq, NULL); > +err_rq: > + xsk_pool_dma_unmap(pool, 0); > +err_xsk_map: > + dma_unmap_single(dma_dev, hdr_dma, vi->hdr_len, DMA_TO_DEVICE); > + return err; > +} > + > +static int virtnet_xsk_pool_disable(struct net_device *dev, u16 qid) > +{ > + struct virtnet_info *vi = netdev_priv(dev); > + struct xsk_buff_pool *pool; > + struct device *dma_dev; > + struct receive_queue *rq; > + struct send_queue *sq; > + int err1, err2; > + > + if (qid >= vi->curr_queue_pairs) > + return -EINVAL; > + > + sq = &vi->sq[qid]; > + rq = &vi->rq[qid]; > + > + pool = sq->xsk.pool; > + > + err1 = virtnet_sq_bind_xsk_pool(vi, sq, NULL); > + err2 = virtnet_rq_bind_xsk_pool(vi, rq, NULL); > + > + xsk_pool_dma_unmap(pool, 0); > + > + dma_dev = virtqueue_dma_dev(rq->vq); > + > + dma_unmap_single(dma_dev, sq->xsk.hdr_dma_address, vi->hdr_len, DMA_TO_DEVICE); > + > + return err1 | err2; > +} > + > +static int virtnet_xsk_pool_setup(struct net_device *dev, struct netdev_bpf *xdp) > +{ > + if (xdp->xsk.pool) > + return virtnet_xsk_pool_enable(dev, xdp->xsk.pool, > + xdp->xsk.queue_id); > + else > + return virtnet_xsk_pool_disable(dev, xdp->xsk.queue_id); > +} > + > static int virtnet_xdp_set(struct net_device *dev, struct bpf_prog *prog, > struct netlink_ext_ack *extack) > { > @@ -5302,6 +5499,8 @@ static int virtnet_xdp(struct net_device *dev, struct netdev_bpf *xdp) > switch (xdp->command) { > case XDP_SETUP_PROG: > return virtnet_xdp_set(dev, xdp->prog, xdp->extack); > + case XDP_SETUP_XSK_POOL: > + return virtnet_xsk_pool_setup(dev, xdp); > default: > return -EINVAL; > } > -- > 2.32.0.3.g01195cf9f > Thanks