From patchwork Tue Nov 7 03:12:24 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Xuan Zhuo X-Patchwork-Id: 13447845 X-Patchwork-Delegate: kuba@kernel.org 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 4B24C12E72; Tue, 7 Nov 2023 03:12:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=none Received: from out30-132.freemail.mail.aliyun.com (out30-132.freemail.mail.aliyun.com [115.124.30.132]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3A423D75; Mon, 6 Nov 2023 19:12:53 -0800 (PST) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R131e4;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=14;SR=0;TI=SMTPD_---0VvsQhei_1699326768; Received: from localhost(mailfrom:xuanzhuo@linux.alibaba.com fp:SMTPD_---0VvsQhei_1699326768) by smtp.aliyun-inc.com; Tue, 07 Nov 2023 11:12:49 +0800 From: Xuan Zhuo To: netdev@vger.kernel.org Cc: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , virtualization@lists.linux-foundation.org, bpf@vger.kernel.org Subject: [PATCH net-next v2 18/21] virtio_net: xsk: rx: introduce receive_xsk() to recv xsk buffer Date: Tue, 7 Nov 2023 11:12:24 +0800 Message-Id: <20231107031227.100015-19-xuanzhuo@linux.alibaba.com> X-Mailer: git-send-email 2.32.0.3.g01195cf9f In-Reply-To: <20231107031227.100015-1-xuanzhuo@linux.alibaba.com> References: <20231107031227.100015-1-xuanzhuo@linux.alibaba.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Git-Hash: 59a160d210e8 X-Patchwork-Delegate: kuba@kernel.org The virtnet_xdp_handler() is re-used. But 1. We need to copy data to create skb for XDP_PASS. 2. We need to call xsk_buff_free() to release the buffer. 3. The handle for xdp_buff is difference. If we pushed this logic into existing receive handle(merge and small), we would have to maintain code scattered inside merge and small (and big). So I think it is a good choice for us to put the xsk code into an independent function. Signed-off-by: Xuan Zhuo --- drivers/net/virtio/main.c | 12 ++-- drivers/net/virtio/virtio_net.h | 4 ++ drivers/net/virtio/xsk.c | 120 ++++++++++++++++++++++++++++++++ drivers/net/virtio/xsk.h | 4 ++ 4 files changed, 135 insertions(+), 5 deletions(-) diff --git a/drivers/net/virtio/main.c b/drivers/net/virtio/main.c index a318b2533b94..095f4acb0577 100644 --- a/drivers/net/virtio/main.c +++ b/drivers/net/virtio/main.c @@ -831,10 +831,10 @@ static void put_xdp_frags(struct xdp_buff *xdp) } } -static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp, - struct net_device *dev, - unsigned int *xdp_xmit, - struct virtnet_rq_stats *stats) +int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp, + struct net_device *dev, + unsigned int *xdp_xmit, + struct virtnet_rq_stats *stats) { struct xdp_frame *xdpf; int err; @@ -1598,7 +1598,9 @@ static void receive_buf(struct virtnet_info *vi, struct virtnet_rq *rq, return; } - if (vi->mergeable_rx_bufs) + if (rq->xsk.pool) + skb = virtnet_receive_xsk(dev, vi, rq, buf, len, xdp_xmit, stats); + else if (vi->mergeable_rx_bufs) skb = receive_mergeable(dev, vi, rq, buf, ctx, len, xdp_xmit, stats); else if (vi->big_packets) diff --git a/drivers/net/virtio/virtio_net.h b/drivers/net/virtio/virtio_net.h index 2005d0cd22e2..f520fec06662 100644 --- a/drivers/net/virtio/virtio_net.h +++ b/drivers/net/virtio/virtio_net.h @@ -339,4 +339,8 @@ void virtnet_tx_pause(struct virtnet_info *vi, struct virtnet_sq *sq); void virtnet_tx_resume(struct virtnet_info *vi, struct virtnet_sq *sq); void virtnet_sq_free_unused_buf(struct virtqueue *vq, void *buf); void virtnet_rq_free_unused_buf(struct virtqueue *vq, void *buf); +int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp, + struct net_device *dev, + unsigned int *xdp_xmit, + struct virtnet_rq_stats *stats); #endif diff --git a/drivers/net/virtio/xsk.c b/drivers/net/virtio/xsk.c index b09c473c29fb..5c7eb19ab04b 100644 --- a/drivers/net/virtio/xsk.c +++ b/drivers/net/virtio/xsk.c @@ -14,6 +14,18 @@ static void sg_fill_dma(struct scatterlist *sg, dma_addr_t addr, u32 len) sg->length = len; } +static unsigned int virtnet_receive_buf_num(struct virtnet_info *vi, char *buf) +{ + struct virtio_net_hdr_mrg_rxbuf *hdr; + + if (vi->mergeable_rx_bufs) { + hdr = (struct virtio_net_hdr_mrg_rxbuf *)buf; + return virtio16_to_cpu(vi->vdev, hdr->num_buffers); + } + + return 1; +} + static void virtnet_xsk_check_queue(struct virtnet_sq *sq) { struct virtnet_info *vi = sq->vq->vdev->priv; @@ -38,6 +50,114 @@ static void virtnet_xsk_check_queue(struct virtnet_sq *sq) netif_stop_subqueue(dev, qnum); } +static void merge_drop_follow_xdp(struct net_device *dev, + struct virtnet_rq *rq, + u32 num_buf, + struct virtnet_rq_stats *stats) +{ + struct xdp_buff *xdp; + u32 len; + + while (num_buf-- > 1) { + xdp = virtqueue_get_buf(rq->vq, &len); + if (unlikely(!xdp)) { + pr_debug("%s: rx error: %d buffers missing\n", + dev->name, num_buf); + dev->stats.rx_length_errors++; + break; + } + u64_stats_add(&stats->bytes, len); + xsk_buff_free(xdp); + } +} + +static struct sk_buff *construct_skb(struct virtnet_rq *rq, + struct xdp_buff *xdp) +{ + unsigned int metasize = xdp->data - xdp->data_meta; + struct sk_buff *skb; + unsigned int size; + + size = xdp->data_end - xdp->data_hard_start; + skb = napi_alloc_skb(&rq->napi, size); + if (unlikely(!skb)) + return NULL; + + skb_reserve(skb, xdp->data_meta - xdp->data_hard_start); + + size = xdp->data_end - xdp->data_meta; + memcpy(__skb_put(skb, size), xdp->data_meta, size); + + if (metasize) { + __skb_pull(skb, metasize); + skb_metadata_set(skb, metasize); + } + + return skb; +} + +struct sk_buff *virtnet_receive_xsk(struct net_device *dev, struct virtnet_info *vi, + struct virtnet_rq *rq, void *buf, + unsigned int len, unsigned int *xdp_xmit, + struct virtnet_rq_stats *stats) +{ + struct virtio_net_hdr_mrg_rxbuf *hdr; + struct sk_buff *skb = NULL; + u32 ret, headroom, num_buf; + struct bpf_prog *prog; + struct xdp_buff *xdp; + + len -= vi->hdr_len; + + xdp = (struct xdp_buff *)buf; + + xsk_buff_set_size(xdp, len); + + hdr = xdp->data - vi->hdr_len; + + num_buf = virtnet_receive_buf_num(vi, (char *)hdr); + if (num_buf > 1) + goto drop; + + headroom = xdp->data - xdp->data_hard_start; + + xdp_prepare_buff(xdp, xdp->data_hard_start, headroom, len, true); + xsk_buff_dma_sync_for_cpu(xdp, rq->xsk.pool); + + ret = XDP_PASS; + rcu_read_lock(); + prog = rcu_dereference(rq->xdp_prog); + if (prog) + ret = virtnet_xdp_handler(prog, xdp, dev, xdp_xmit, stats); + rcu_read_unlock(); + + switch (ret) { + case XDP_PASS: + skb = construct_skb(rq, xdp); + xsk_buff_free(xdp); + break; + + case XDP_TX: + case XDP_REDIRECT: + goto consumed; + + default: + goto drop; + } + + return skb; + +drop: + u64_stats_inc(&stats->drops); + + xsk_buff_free(xdp); + + if (num_buf > 1) + merge_drop_follow_xdp(dev, rq, num_buf, stats); +consumed: + return NULL; +} + int virtnet_add_recvbuf_xsk(struct virtnet_info *vi, struct virtnet_rq *rq, struct xsk_buff_pool *pool, gfp_t gfp) { diff --git a/drivers/net/virtio/xsk.h b/drivers/net/virtio/xsk.h index bef41a3f954e..dbd2839a5f61 100644 --- a/drivers/net/virtio/xsk.h +++ b/drivers/net/virtio/xsk.h @@ -25,4 +25,8 @@ bool virtnet_xsk_xmit(struct virtnet_sq *sq, struct xsk_buff_pool *pool, int virtnet_xsk_wakeup(struct net_device *dev, u32 qid, u32 flag); int virtnet_add_recvbuf_xsk(struct virtnet_info *vi, struct virtnet_rq *rq, struct xsk_buff_pool *pool, gfp_t gfp); +struct sk_buff *virtnet_receive_xsk(struct net_device *dev, struct virtnet_info *vi, + struct virtnet_rq *rq, void *buf, + unsigned int len, unsigned int *xdp_xmit, + struct virtnet_rq_stats *stats); #endif