From patchwork Mon Aug 7 12:26:17 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?6buE5p2w?= X-Patchwork-Id: 13344082 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 71E3C4436 for ; Mon, 7 Aug 2023 12:26:29 +0000 (UTC) Received: from mail-pf1-x430.google.com (mail-pf1-x430.google.com [IPv6:2607:f8b0:4864:20::430]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3C98B128 for ; Mon, 7 Aug 2023 05:26:27 -0700 (PDT) Received: by mail-pf1-x430.google.com with SMTP id d2e1a72fcca58-686b9964ae2so3025676b3a.3 for ; Mon, 07 Aug 2023 05:26:27 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1691411186; x=1692015986; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=VNxERTokHn2QOzCO7nu1QH5j2GU8N7cGLZ9USDe1a7I=; b=UxOEpaG2o+xqx/J3NAFr9T/TXCrWhWtpPYaNl+rxWd6X06ltJfGQuZyB+mySSCYSOH OiBmgM1AndvMiLctAaeJGlS8Nn3YPNEnH3rXxClTohGrSXieLByWmK064JmlnmJzTOJt KKYC0h4iWIwAua6np92zxX6F9LG30TlbRT7XV2GLSrzz8L4quPJ4kcYB9PUWUwGLrzSX UQEdcqd9F687AKaceiRKcM9L7hxt5agKkQbKQkV8TKJO6EnR3PMkUHEJ825nfROlZeJR lXSUzwtEqxNLlKTYMCZ04bZkxWvNoAVqgwpuJvFols1+9RpvLvplwJyVfgpJxmcOSges /0dw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1691411186; x=1692015986; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=VNxERTokHn2QOzCO7nu1QH5j2GU8N7cGLZ9USDe1a7I=; b=Yb6Zg505Bx260BldfoXMw8T4OjpqoY0GCBs1RKmJP745ZZlVGFl+Xysb2RpAI8+JIw dZ2Up5j1wv04YEPnzX1E6rlHwyp9syjTT0FqQu0V+MmucexPQrEyk0XNX+j33L9VjLr8 K+U821/1X3DQdtjX74P3QbhG5MYQ5fWYzRITuEHsWfAUM+KR26rV4TcfAk8C15AZqNFR fM/HTIcn3GPcJik8MAW1FovqS3SsFVIUjR5Fc6lIMKRUpOSK/de6MVFMI3xazVQJX/bW Xk928vRuNX8yzxRAfHoYSRRtZpHkPnsMZ22B6ZcrpH4ujjTpreVAtrJtidcYa3GIPulI C35g== X-Gm-Message-State: AOJu0YxU5namwuu7rmsZvKmbMgyvFxqN8X7y9SZsdXMgiJ9gKhnxJ71N 8KMCJ6bTWz54jIOydVOyvmbW5Q== X-Google-Smtp-Source: AGHT+IGkLvXck+BgnTaLCKmOThWuPtHwOWLg4xPo4gzumYuiSTN4y35ZcW1uUAKYtat1ZPHip9hoIg== X-Received: by 2002:a05:6a00:a17:b0:666:b0e7:10ea with SMTP id p23-20020a056a000a1700b00666b0e710eamr9238745pfh.31.1691411186600; Mon, 07 Aug 2023 05:26:26 -0700 (PDT) Received: from C02FG34NMD6R.bytedance.net ([2408:8656:30f8:e020::b]) by smtp.gmail.com with ESMTPSA id v19-20020aa78093000000b00672401787c6sm6060354pff.109.2023.08.07.05.26.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 07 Aug 2023 05:26:25 -0700 (PDT) From: Albert Huang To: Cc: Albert Huang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , netdev@vger.kernel.org (open list:NETWORKING DRIVERS), linux-kernel@vger.kernel.org (open list), bpf@vger.kernel.org (open list:XDP (eXpress Data Path)) Subject: [RFC v2 Optimizing veth xsk performance 8/9] veth: af_xdp tx batch support for ipv4 udp Date: Mon, 7 Aug 2023 20:26:17 +0800 Message-Id: <20230807122617.85882-1-huangjie.albert@bytedance.com> X-Mailer: git-send-email 2.37.1 (Apple Git-137.1) In-Reply-To: <20230807120434.83644-1-huangjie.albert@bytedance.com> References: <20230807120434.83644-1-huangjie.albert@bytedance.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Spam-Status: No, score=-2.1 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_BLOCKED, SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net X-Patchwork-Delegate: kuba@kernel.org X-Patchwork-State: RFC A typical topology is shown below: veth<--------veth-peer 1 | |2 | bridge<------->eth0(such as mlnx5 NIC) If you use af_xdp to send packets from veth to a physical NIC, it needs to go through some software paths, so we can refer to the implementation of kernel GSO. When af_xdp sends packets out from veth, consider aggregating packets and send a large packet from the veth virtual NIC to the physical NIC. performance:(test weth libxdp lib) AF_XDP without batch : 480 Kpps (with ksoftirqd 100% cpu) AF_XDP with batch : 1.5 Mpps (with ksoftirqd 15% cpu) With af_xdp batch, the libxdp user-space program reaches a bottleneck. Therefore, the softirq did not reach the limit. Signed-off-by: Albert Huang --- drivers/net/veth.c | 408 ++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 387 insertions(+), 21 deletions(-) diff --git a/drivers/net/veth.c b/drivers/net/veth.c index ac78d6a87416..70489d017b51 100644 --- a/drivers/net/veth.c +++ b/drivers/net/veth.c @@ -29,6 +29,7 @@ #include #include #include +#include #define DRV_NAME "veth" #define DRV_VERSION "1.0" @@ -103,6 +104,23 @@ struct veth_xdp_tx_bq { unsigned int count; }; +struct veth_batch_tuple { + __u8 protocol; + __be32 saddr; + __be32 daddr; + __be16 source; + __be16 dest; + __be16 batch_size; + __be16 batch_segs; + bool batch_enable; + bool batch_flush; +}; + +struct veth_seg_info { + u32 segs; + u64 desc[] ____cacheline_aligned_in_smp; +}; + /* * ethtool interface */ @@ -1078,11 +1096,340 @@ static struct sk_buff *veth_build_skb(void *head, int headroom, int len, return skb; } +static void veth_xsk_destruct_skb(struct sk_buff *skb) +{ + struct skb_shared_info *si = skb_shinfo(skb); + struct xsk_buff_pool *pool = (struct xsk_buff_pool *)si->destructor_arg_xsk_pool; + struct veth_seg_info *seg_info = (struct veth_seg_info *)si->destructor_arg; + unsigned long flags; + u32 index = 0; + u64 addr; + + /* release cq */ + spin_lock_irqsave(&pool->cq_lock, flags); + for (index = 0; index < seg_info->segs; index++) { + addr = (u64)(long)seg_info->desc[index]; + xsk_tx_completed_addr(pool, addr); + } + spin_unlock_irqrestore(&pool->cq_lock, flags); + + kfree(seg_info); + si->destructor_arg = NULL; + si->destructor_arg_xsk_pool = NULL; +} + +static struct sk_buff *veth_build_gso_head_skb(struct net_device *dev, + char *buff, u32 tot_len, + u32 headroom, u32 iph_len, + u32 th_len) +{ + struct sk_buff *skb = NULL; + int err = 0; + + skb = alloc_skb(tot_len, GFP_KERNEL); + if (unlikely(!skb)) + return NULL; + + /* header room contains the eth header */ + skb_reserve(skb, headroom - ETH_HLEN); + skb_put(skb, ETH_HLEN + iph_len + th_len); + skb_shinfo(skb)->gso_segs = 0; + + err = skb_store_bits(skb, 0, buff, ETH_HLEN + iph_len + th_len); + if (unlikely(err)) { + kfree_skb(skb); + return NULL; + } + + skb->protocol = eth_type_trans(skb, dev); + skb->network_header = skb->mac_header + ETH_HLEN; + skb->transport_header = skb->network_header + iph_len; + skb->ip_summed = CHECKSUM_PARTIAL; + + return skb; +} + +/* only ipv4 udp match + * to do: tcp and ipv6 + */ +static inline bool veth_segment_match(struct veth_batch_tuple *tuple, + struct iphdr *iph, struct udphdr *udph) +{ + if (tuple->protocol == iph->protocol && + tuple->saddr == iph->saddr && + tuple->daddr == iph->daddr && + tuple->source == udph->source && + tuple->dest == udph->dest && + tuple->batch_size == ntohs(udph->len)) { + tuple->batch_flush = false; + return true; + } + + tuple->batch_flush = true; + return false; +} + +static inline void veth_tuple_init(struct veth_batch_tuple *tuple, + struct iphdr *iph, struct udphdr *udph) +{ + tuple->protocol = iph->protocol; + tuple->saddr = iph->saddr; + tuple->daddr = iph->daddr; + tuple->source = udph->source; + tuple->dest = udph->dest; + tuple->batch_flush = false; + tuple->batch_size = ntohs(udph->len); + tuple->batch_segs = 0; +} + +static inline bool veth_batch_ip_check_v4(struct iphdr *iph, u32 len) +{ + if (len <= (ETH_HLEN + sizeof(*iph))) + return false; + + if (iph->ihl < 5 || iph->version != 4 || len < (iph->ihl * 4 + ETH_HLEN)) + return false; + + return true; +} + +static struct sk_buff *veth_build_skb_batch_udp(struct net_device *dev, + struct xsk_buff_pool *pool, + struct xdp_desc *desc, + struct veth_batch_tuple *tuple, + struct sk_buff *prev_skb) +{ + u32 hr, len, ts, index, iph_len, th_len, data_offset, data_len, tot_len; + struct veth_seg_info *seg_info; + void *buffer; + struct udphdr *udph; + struct iphdr *iph; + struct sk_buff *skb; + struct page *page; + u32 seg_len = 0; + int hh_len = 0; + u64 addr; + + addr = desc->addr; + len = desc->len; + + /* l2 reserved len */ + hh_len = LL_RESERVED_SPACE(dev); + hr = max(NET_SKB_PAD, L1_CACHE_ALIGN(hh_len)); + + /* data points to eth header */ + buffer = (unsigned char *)xsk_buff_raw_get_data(pool, addr); + + iph = (struct iphdr *)(buffer + ETH_HLEN); + iph_len = iph->ihl * 4; + + udph = (struct udphdr *)(buffer + ETH_HLEN + iph_len); + th_len = sizeof(struct udphdr); + + if (tuple->batch_flush) + veth_tuple_init(tuple, iph, udph); + + ts = pool->unaligned ? len : pool->chunk_size; + + data_offset = offset_in_page(buffer) + ETH_HLEN + iph_len + th_len; + data_len = len - (ETH_HLEN + iph_len + th_len); + + /* head is null or this is a new 5 tuple */ + if (!prev_skb || !veth_segment_match(tuple, iph, udph)) { + tot_len = hr + iph_len + th_len; + skb = veth_build_gso_head_skb(dev, buffer, tot_len, hr, iph_len, th_len); + if (!skb) { + /* to do: handle here for skb */ + return NULL; + } + + /* store information for gso */ + seg_len = struct_size(seg_info, desc, MAX_SKB_FRAGS); + seg_info = kmalloc(seg_len, GFP_KERNEL); + if (!seg_info) { + /* to do */ + kfree_skb(skb); + return NULL; + } + } else { + skb = prev_skb; + skb_shinfo(skb)->gso_type = SKB_GSO_UDP_L4 | SKB_GSO_PARTIAL; + skb_shinfo(skb)->gso_size = data_len; + skb->ip_summed = CHECKSUM_PARTIAL; + + /* max segment is MAX_SKB_FRAGS */ + if (skb_shinfo(skb)->gso_segs >= MAX_SKB_FRAGS - 1) + tuple->batch_flush = true; + + seg_info = (struct veth_seg_info *)skb_shinfo(skb)->destructor_arg; + } + + /* offset in umem pool buffer */ + addr = buffer - pool->addrs; + + /* get the page of the desc */ + page = pool->umem->pgs[addr >> PAGE_SHIFT]; + + /* in order to avoid to get freed by kfree_skb */ + get_page(page); + + /* desc.data can not hold in two */ + skb_fill_page_desc(skb, skb_shinfo(skb)->gso_segs, page, data_offset, data_len); + + skb->len += data_len; + skb->data_len += data_len; + skb->truesize += ts; + skb->dev = dev; + + /* later we will support gso for this */ + index = skb_shinfo(skb)->gso_segs; + seg_info->desc[index] = desc->addr; + seg_info->segs = ++index; + skb_shinfo(skb)->gso_segs++; + + skb_shinfo(skb)->destructor_arg = (void *)(long)seg_info; + skb_shinfo(skb)->destructor_arg_xsk_pool = (void *)(long)pool; + skb->destructor = veth_xsk_destruct_skb; + + /* to do: + * add skb to sock. may be there is no need to do for this + * and this might be multiple xsk sockets involved, so it's + * difficult to determine which socket is sending the data. + * refcount_add(ts, &xs->sk.sk_wmem_alloc); + */ + return skb; +} + +static inline struct sk_buff *veth_build_skb_def(struct net_device *dev, + struct xsk_buff_pool *pool, struct xdp_desc *desc) +{ + struct sk_buff *skb = NULL; + struct page *page; + void *buffer; + void *vaddr; + + page = dev_alloc_page(); + if (!page) + return NULL; + + buffer = (unsigned char *)xsk_buff_raw_get_data(pool, desc->addr); + + vaddr = page_to_virt(page); + memcpy(vaddr + pool->headroom, buffer, desc->len); + skb = veth_build_skb(vaddr, pool->headroom, desc->len, PAGE_SIZE); + if (!skb) { + put_page(page); + return NULL; + } + + skb->protocol = eth_type_trans(skb, dev); + + return skb; +} + +/* To call the following function, the following conditions must be met: + * 1.The data packet must be a standard Ethernet data packet + * 2. Data packets support batch sending + */ +static inline struct sk_buff *veth_build_skb_batch_v4(struct net_device *dev, + struct xsk_buff_pool *pool, + struct xdp_desc *desc, + struct veth_batch_tuple *tuple, + struct sk_buff *prev_skb) +{ + struct iphdr *iph; + void *buffer; + u64 addr; + + addr = desc->addr; + buffer = (unsigned char *)xsk_buff_raw_get_data(pool, addr); + iph = (struct iphdr *)(buffer + ETH_HLEN); + if (!veth_batch_ip_check_v4(iph, desc->len)) + goto normal; + + switch (iph->protocol) { + case IPPROTO_UDP: + return veth_build_skb_batch_udp(dev, pool, desc, tuple, prev_skb); + default: + break; + } +normal: + tuple->batch_enable = false; + return veth_build_skb_def(dev, pool, desc); +} + +/* Zero copy needs to meet the following conditions： + * 1. The data content of tx desc must be within one page + * 2、the tx desc must support batch xmit, which seted by userspace + */ +static inline bool veth_batch_desc_check(void *buff, u32 len) +{ + u32 offset; + + offset = offset_in_page(buff); + if (PAGE_SIZE - offset < len) + return false; + + return true; +} + +/* here must be a ipv4 or ipv6 packet */ +static inline struct sk_buff *veth_build_skb_batch(struct net_device *dev, + struct xsk_buff_pool *pool, + struct xdp_desc *desc, + struct veth_batch_tuple *tuple, + struct sk_buff *prev_skb) +{ + const struct ethhdr *eth; + void *buffer; + + buffer = xsk_buff_raw_get_data(pool, desc->addr); + if (!veth_batch_desc_check(buffer, desc->len)) + goto normal; + + eth = (struct ethhdr *)buffer; + switch (ntohs(eth->h_proto)) { + case ETH_P_IP: + tuple->batch_enable = true; + return veth_build_skb_batch_v4(dev, pool, desc, tuple, prev_skb); + /* to do: not support yet, just build skb, no batch */ + case ETH_P_IPV6: + fallthrough; + default: + break; + } + +normal: + tuple->batch_flush = false; + tuple->batch_enable = false; + return veth_build_skb_def(dev, pool, desc); +} + +/* just support ipv4 udp batch + * to do: ipv4 tcp and ipv6 + */ +static inline void veth_skb_batch_checksum(struct sk_buff *skb) +{ + struct iphdr *iph = ip_hdr(skb); + struct udphdr *uh = udp_hdr(skb); + int ip_tot_len = skb->len; + int udp_len = skb->len - (skb->transport_header - skb->network_header); + + iph->tot_len = htons(ip_tot_len); + ip_send_check(iph); + uh->len = htons(udp_len); + uh->check = 0; + + udp4_hwcsum(skb, iph->saddr, iph->daddr); +} + static int veth_xsk_tx_xmit(struct veth_sq *sq, struct xsk_buff_pool *xsk_pool, int budget) { struct veth_priv *priv, *peer_priv; struct net_device *dev, *peer_dev; + struct veth_batch_tuple tuple; struct veth_stats stats = {}; + struct sk_buff *prev_skb = NULL; struct sk_buff *skb = NULL; struct veth_rq *peer_rq; struct xdp_desc desc; @@ -1093,24 +1440,23 @@ static int veth_xsk_tx_xmit(struct veth_sq *sq, struct xsk_buff_pool *xsk_pool, peer_dev = priv->peer; peer_priv = netdev_priv(peer_dev); - /* todo: queue index must set before this */ + /* queue_index set in napi enable + * to do:may be we should select rq by 5-tuple or hash + */ peer_rq = &peer_priv->rq[sq->queue_index]; + memset(&tuple, 0, sizeof(tuple)); + /* set xsk wake up flag, to do: where to disable */ if (xsk_uses_need_wakeup(xsk_pool)) xsk_set_tx_need_wakeup(xsk_pool); while (budget-- > 0) { unsigned int truesize = 0; - struct page *page; - void *vaddr; - void *addr; if (!xsk_tx_peek_desc(xsk_pool, &desc)) break; - addr = xsk_buff_raw_get_data(xsk_pool, desc.addr); - /* can not hold all data in a page */ truesize = SKB_DATA_ALIGN(sizeof(struct skb_shared_info)); truesize += desc.len + xsk_pool->headroom; @@ -1120,30 +1466,50 @@ static int veth_xsk_tx_xmit(struct veth_sq *sq, struct xsk_buff_pool *xsk_pool, break; } - page = dev_alloc_page(); - if (!page) { + skb = veth_build_skb_batch(peer_dev, xsk_pool, &desc, &tuple, prev_skb); + if (!skb) { + stats.rx_drops++; xsk_tx_completed_addr(xsk_pool, desc.addr); - stats.xdp_drops++; - break; + if (prev_skb != skb) { + napi_gro_receive(&peer_rq->xdp_napi, prev_skb); + prev_skb = NULL; + } + continue; } - vaddr = page_to_virt(page); - - memcpy(vaddr + xsk_pool->headroom, addr, desc.len); - xsk_tx_completed_addr(xsk_pool, desc.addr); - skb = veth_build_skb(vaddr, xsk_pool->headroom, desc.len, PAGE_SIZE); - if (!skb) { - put_page(page); - stats.xdp_drops++; - break; + if (!tuple.batch_enable) { + xsk_tx_completed_addr(xsk_pool, desc.addr); + /* flush the prev skb first to avoid out of order */ + if (prev_skb != skb && prev_skb) { + veth_skb_batch_checksum(prev_skb); + napi_gro_receive(&peer_rq->xdp_napi, prev_skb); + prev_skb = NULL; + } + napi_gro_receive(&peer_rq->xdp_napi, skb); + skb = NULL; + } else { + if (prev_skb && tuple.batch_flush) { + veth_skb_batch_checksum(prev_skb); + napi_gro_receive(&peer_rq->xdp_napi, prev_skb); + if (prev_skb == skb) + prev_skb = skb = NULL; + else + prev_skb = skb; + } else { + prev_skb = skb; + } } - skb->protocol = eth_type_trans(skb, peer_dev); - napi_gro_receive(&peer_rq->xdp_napi, skb); stats.xdp_bytes += desc.len; done++; } + /* means there is a skb need to send to peer_rq (batch)*/ + if (skb) { + veth_skb_batch_checksum(skb); + napi_gro_receive(&peer_rq->xdp_napi, skb); + } + /* release, move consumer，and wakeup the producer */ if (done) { napi_schedule(&peer_rq->xdp_napi);