From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3848B10941; Fri, 20 Oct 2023 08:06:33 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from out30-113.freemail.mail.aliyun.com (out30-113.freemail.mail.aliyun.com [115.124.30.113]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 17E1EE8; Fri, 20 Oct 2023 01:06:30 -0700 (PDT) X-Alimail-AntiSpam:AC=PASS;BC=-1|-1;BR=01201311R211e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045192;MF=xuanzhuo@linux.alibaba.com;NM=1;PH=DS;RN=13;SR=0;TI=SMTPD_---0VuWbaGz_1697789184; Received: from localhost(mailfrom:xuanzhuo@linux.alibaba.com fp:SMTPD_---0VuWbaGz_1697789184) by smtp.aliyun-inc.com; Fri, 20 Oct 2023 16:06:25 +0800 Message-ID: <1697789168.0141354-3-xuanzhuo@linux.alibaba.com> Subject: Re: [PATCH net-next v1 11/19] virtio_net: xsk: tx: support tx Date: Fri, 20 Oct 2023 16:06:08 +0800 From: Xuan Zhuo To: Jason Wang Cc: netdev@vger.kernel.org, "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , "Michael S. Tsirkin" , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , virtualization@lists.linux-foundation.org, bpf@vger.kernel.org References: <20231016120033.26933-1-xuanzhuo@linux.alibaba.com> <20231016120033.26933-12-xuanzhuo@linux.alibaba.com> In-Reply-To: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: On Fri, 20 Oct 2023 14:52:08 +0800, Jason Wang wrote: > On Mon, Oct 16, 2023 at 8:01=E2=80=AFPM Xuan Zhuo wrote: > > > > The driver's tx napi is very important for XSK. It is responsible for > > obtaining data from the XSK queue and sending it out. > > > > At the beginning, we need to trigger tx napi. > > > > Signed-off-by: Xuan Zhuo > > --- > > drivers/net/virtio/main.c | 18 +++++- > > drivers/net/virtio/virtio_net.h | 3 +- > > drivers/net/virtio/xsk.c | 108 ++++++++++++++++++++++++++++++++ > > drivers/net/virtio/xsk.h | 13 ++++ > > 4 files changed, 140 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/net/virtio/main.c b/drivers/net/virtio/main.c > > index b320770e5f4e..a08429bef61f 100644 > > --- a/drivers/net/virtio/main.c > > +++ b/drivers/net/virtio/main.c > > @@ -2054,7 +2054,9 @@ static int virtnet_poll_tx(struct napi_struct *na= pi, int budget) > > struct virtnet_sq *sq =3D container_of(napi, struct virtnet_sq,= napi); > > struct virtnet_info *vi =3D sq->vq->vdev->priv; > > unsigned int index =3D vq2txq(sq->vq); > > + struct xsk_buff_pool *pool; > > struct netdev_queue *txq; > > + int busy =3D 0; > > int opaque; > > bool done; > > > > @@ -2067,11 +2069,25 @@ static int virtnet_poll_tx(struct napi_struct *= napi, int budget) > > txq =3D netdev_get_tx_queue(vi->dev, index); > > __netif_tx_lock(txq, raw_smp_processor_id()); > > virtqueue_disable_cb(sq->vq); > > - free_old_xmit(sq, true); > > + > > + rcu_read_lock(); > > + pool =3D rcu_dereference(sq->xsk.pool); > > + if (pool) { > > + busy |=3D virtnet_xsk_xmit(sq, pool, budget); > > + rcu_read_unlock(); > > + } else { > > + rcu_read_unlock(); > > + free_old_xmit(sq, true); > > + } > > > > if (sq->vq->num_free >=3D 2 + MAX_SKB_FRAGS) > > netif_tx_wake_queue(txq); > > > > + if (busy) { > > + __netif_tx_unlock(txq); > > + return budget; > > + } > > + > > opaque =3D virtqueue_enable_cb_prepare(sq->vq); > > > > done =3D napi_complete_done(napi, 0); > > diff --git a/drivers/net/virtio/virtio_net.h b/drivers/net/virtio/virti= o_net.h > > index 9e69b6c5921b..3bbb1f5baad5 100644 > > --- a/drivers/net/virtio/virtio_net.h > > +++ b/drivers/net/virtio/virtio_net.h > > @@ -9,7 +9,8 @@ > > #include > > > > #define VIRTIO_XDP_FLAG BIT(0) > > -#define VIRTIO_XMIT_DATA_MASK (VIRTIO_XDP_FLAG) > > +#define VIRTIO_XSK_FLAG BIT(1) > > +#define VIRTIO_XMIT_DATA_MASK (VIRTIO_XDP_FLAG | VIRTIO_XSK_FLAG) > > > > /* RX packet size EWMA. The average packet size is used to determine t= he packet > > * buffer size when refilling RX rings. As the entire RX ring may be r= efilled > > diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c > > index dddd01962a3f..0e775a9d270f 100644 > > --- a/drivers/net/virtio/xsk.c > > +++ b/drivers/net/virtio/xsk.c > > @@ -7,6 +7,114 @@ > > > > static struct virtio_net_hdr_mrg_rxbuf xsk_hdr; > > > > +static void sg_fill_dma(struct scatterlist *sg, dma_addr_t addr, u32 l= en) > > +{ > > + sg->dma_address =3D addr; > > + sg->length =3D len; > > +} > > + > > +static void virtnet_xsk_check_queue(struct virtnet_sq *sq) > > +{ > > + struct virtnet_info *vi =3D sq->vq->vdev->priv; > > + struct net_device *dev =3D vi->dev; > > + int qnum =3D sq - vi->sq; > > + > > + /* If it is a raw buffer queue, it does not check whether the s= tatus > > + * of the queue is stopped when sending. So there is no need to= check > > + * the situation of the raw buffer queue. > > + */ > > + if (virtnet_is_xdp_raw_buffer_queue(vi, qnum)) > > + return; > > + > > + /* If this sq is not the exclusive queue of the current cpu, > > + * then it may be called by start_xmit, so check it running out > > + * of space. > > + * > > + * Stop the queue to avoid getting packets that we are > > + * then unable to transmit. Then wait the tx interrupt. > > + */ > > + if (sq->vq->num_free < 2 + MAX_SKB_FRAGS) > > + netif_stop_subqueue(dev, qnum); > > +} > > + > > +static int virtnet_xsk_xmit_one(struct virtnet_sq *sq, > > + struct xsk_buff_pool *pool, > > + struct xdp_desc *desc) > > +{ > > + struct virtnet_info *vi; > > + dma_addr_t addr; > > + > > + vi =3D sq->vq->vdev->priv; > > + > > + addr =3D xsk_buff_raw_get_dma(pool, desc->addr); > > + xsk_buff_raw_dma_sync_for_device(pool, addr, desc->len); > > + > > + sg_init_table(sq->sg, 2); > > + > > + sg_fill_dma(sq->sg, sq->xsk.hdr_dma_address, vi->hdr_len); > > + sg_fill_dma(sq->sg + 1, addr, desc->len); > > + > > + return virtqueue_add_outbuf(sq->vq, sq->sg, 2, > > + virtnet_xsk_to_ptr(desc->len), GFP_= ATOMIC); > > +} > > + > > +static int virtnet_xsk_xmit_batch(struct virtnet_sq *sq, > > + struct xsk_buff_pool *pool, > > + unsigned int budget, > > + struct virtnet_sq_stats *stats) > > +{ > > + struct xdp_desc *descs =3D pool->tx_descs; > > + u32 nb_pkts, max_pkts, i; > > + bool kick =3D false; > > + int err; > > + > > + max_pkts =3D min_t(u32, budget, sq->vq->num_free / 2); > > Need document why num_free / 2 is chosen here. Will fix. Thanks. > > Others look fine. > > Thanks > > > > + > > + nb_pkts =3D xsk_tx_peek_release_desc_batch(pool, max_pkts); > > + if (!nb_pkts) > > + return 0; > > + > > + for (i =3D 0; i < nb_pkts; i++) { > > + err =3D virtnet_xsk_xmit_one(sq, pool, &descs[i]); > > + if (unlikely(err)) > > + break; > > + > > + kick =3D true; > > + } > > + > > + if (kick && virtqueue_kick_prepare(sq->vq) && virtqueue_notify(= sq->vq)) > > + ++stats->kicks; > > + > > + stats->xdp_tx +=3D i; > > + > > + return i; > > +} > > + > > +bool virtnet_xsk_xmit(struct virtnet_sq *sq, struct xsk_buff_pool *poo= l, > > + int budget) > > +{ > > + struct virtnet_sq_stats stats =3D {}; > > + int sent; > > + > > + virtnet_free_old_xmit(sq, true, &stats); > > + > > + sent =3D virtnet_xsk_xmit_batch(sq, pool, budget, &stats); > > + > > + virtnet_xsk_check_queue(sq); > > + > > + u64_stats_update_begin(&sq->stats.syncp); > > + sq->stats.packets +=3D stats.packets; > > + sq->stats.bytes +=3D stats.bytes; > > + sq->stats.kicks +=3D stats.kicks; > > + sq->stats.xdp_tx +=3D stats.xdp_tx; > > + u64_stats_update_end(&sq->stats.syncp); > > + > > + if (xsk_uses_need_wakeup(pool)) > > + xsk_set_tx_need_wakeup(pool); > > + > > + return sent =3D=3D budget; > > +} > > + > > static int virtnet_rq_bind_xsk_pool(struct virtnet_info *vi, struct vi= rtnet_rq *rq, > > struct xsk_buff_pool *pool) > > { > > diff --git a/drivers/net/virtio/xsk.h b/drivers/net/virtio/xsk.h > > index 1918285c310c..73ca8cd5308b 100644 > > --- a/drivers/net/virtio/xsk.h > > +++ b/drivers/net/virtio/xsk.h > > @@ -3,5 +3,18 @@ > > #ifndef __XSK_H__ > > #define __XSK_H__ > > > > +#define VIRTIO_XSK_FLAG_OFFSET 4 > > + > > +static inline void *virtnet_xsk_to_ptr(u32 len) > > +{ > > + unsigned long p; > > + > > + p =3D len << VIRTIO_XSK_FLAG_OFFSET; > > + > > + return (void *)(p | VIRTIO_XSK_FLAG); > > +} > > + > > int virtnet_xsk_pool_setup(struct net_device *dev, struct netdev_bpf *= xdp); > > +bool virtnet_xsk_xmit(struct virtnet_sq *sq, struct xsk_buff_pool *poo= l, > > + int budget); > > #endif > > -- > > 2.32.0.3.g01195cf9f > > >