From patchwork Fri Jul 14 11:36:21 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Fijalkowski, Maciej" X-Patchwork-Id: 13313545 X-Patchwork-Delegate: bpf@iogearbox.net 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 0A91F13AD6; Fri, 14 Jul 2023 11:37:10 +0000 (UTC) Received: from mga12.intel.com (mga12.intel.com [192.55.52.136]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 91C8D30CB; Fri, 14 Jul 2023 04:37:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1689334629; x=1720870629; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=voQcv4ZcFGVey2qm8OfatkEyaAG96edID39xcVlUR14=; b=hD3930sc3zgvlyxAvhvuYTNRrFvVcH9knVIVgfQTyZlWxk/PXcuFlI1a 7IgZgmG9zyple5f4fzGxtFkSVTUqiJhqbxXIXqFuaAXnlIi5i/SkXX5le 9Ft5mis8FroH5ljT3+zrh2zJlvVM2ZKNzCsrDuZc4P57jPLqrzgef/9Tn gRZY62l5ku6vx5TYwCDkO6493ttxsOyvI/9+BBeYof3+wKrQkIdNK5L67 LwPLezEm9Scru5foXX8p+7r1aTDZnS98kEPTSycekM1PEMfIH2aMe+jS3 G33+47uvW+3dsAuYSwWDZtLjMd3DpLOPQWjbKCDMQkOeLJ7zSYdNeO7Pp g==; X-IronPort-AV: E=McAfee;i="6600,9927,10770"; a="345048138" X-IronPort-AV: E=Sophos;i="6.01,205,1684825200"; d="scan'208";a="345048138" Received: from orsmga004.jf.intel.com ([10.7.209.38]) by fmsmga106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Jul 2023 04:37:01 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6600,9927,10770"; a="846425152" X-IronPort-AV: E=Sophos;i="6.01,205,1684825200"; d="scan'208";a="846425152" Received: from boxer.igk.intel.com ([10.102.20.173]) by orsmga004.jf.intel.com with ESMTP; 14 Jul 2023 04:36:58 -0700 From: Maciej Fijalkowski To: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org Cc: netdev@vger.kernel.org, magnus.karlsson@intel.com, bjorn@kernel.org, tirthendu.sarkar@intel.com, toke@kernel.org, kuba@kernel.org, horms@kernel.org Subject: [PATCH v6 bpf-next 05/24] xsk: add support for AF_XDP multi-buffer on Rx path Date: Fri, 14 Jul 2023 13:36:21 +0200 Message-Id: <20230714113640.556893-6-maciej.fijalkowski@intel.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20230714113640.556893-1-maciej.fijalkowski@intel.com> References: <20230714113640.556893-1-maciej.fijalkowski@intel.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,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF, RCVD_IN_DNSWL_BLOCKED,SPF_HELO_PASS,SPF_NONE,T_SCC_BODY_TEXT_LINE, URIBL_BLOCKED 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: bpf@iogearbox.net From: Tirthendu Sarkar Add multi-buffer support for AF_XDP by extending the XDP multi-buffer support to be reflected in user-space when a packet is redirected to an AF_XDP socket. In the XDP implementation, the NIC driver builds the xdp_buff from the first frag of the packet and adds any subsequent frags in the skb_shinfo area of the xdp_buff. In AF_XDP core, XDP buffers are allocated from xdp_sock's pool and data is copied from the driver's xdp_buff and frags. Once an allocated XDP buffer is full and there is still data to be copied, the 'XDP_PKT_CONTD' flag in'options' field of the corresponding xdp ring descriptor is set and passed to the application. When application sees the aforementioned flag set it knows there is pending data for this packet that will be carried in the following descriptors. If there is no more data to be copied, the flag in 'options' field is cleared for that descriptor signalling EOP to the application. If application reads a batch of descriptors using for example the libxdp interfaces, it is not guaranteed that the batch will end with a full packet. It might end in the middle of a packet and the rest of the frames of that packet will arrive at the beginning of the next batch. AF_XDP ensures that only a complete packet (along with all its frags) is sent to application. Signed-off-by: Tirthendu Sarkar --- net/core/filter.c | 7 +-- net/xdp/xsk.c | 110 ++++++++++++++++++++++++++++++++++++---------- 2 files changed, 88 insertions(+), 29 deletions(-) diff --git a/net/core/filter.c b/net/core/filter.c index 06ba0e56e369..b4410dc841a0 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -4345,13 +4345,8 @@ int xdp_do_redirect(struct net_device *dev, struct xdp_buff *xdp, struct bpf_redirect_info *ri = this_cpu_ptr(&bpf_redirect_info); enum bpf_map_type map_type = ri->map_type; - if (map_type == BPF_MAP_TYPE_XSKMAP) { - /* XDP_REDIRECT is not supported AF_XDP yet. */ - if (unlikely(xdp_buff_has_frags(xdp))) - return -EOPNOTSUPP; - + if (map_type == BPF_MAP_TYPE_XSKMAP) return __xdp_do_redirect_xsk(ri, dev, xdp, xdp_prog); - } return __xdp_do_redirect_frame(ri, dev, xdp_convert_buff_to_frame(xdp), xdp_prog); diff --git a/net/xdp/xsk.c b/net/xdp/xsk.c index 8e2cf002573e..ad40e78eaaa6 100644 --- a/net/xdp/xsk.c +++ b/net/xdp/xsk.c @@ -159,43 +159,107 @@ static int xsk_rcv_zc(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) return __xsk_rcv_zc(xs, xskb, len, 0); } -static void xsk_copy_xdp(struct xdp_buff *to, struct xdp_buff *from, u32 len) +static void *xsk_copy_xdp_start(struct xdp_buff *from) { - void *from_buf, *to_buf; - u32 metalen; + if (unlikely(xdp_data_meta_unsupported(from))) + return from->data; + else + return from->data_meta; +} - if (unlikely(xdp_data_meta_unsupported(from))) { - from_buf = from->data; - to_buf = to->data; - metalen = 0; - } else { - from_buf = from->data_meta; - metalen = from->data - from->data_meta; - to_buf = to->data - metalen; - } +static u32 xsk_copy_xdp(void *to, void **from, u32 to_len, + u32 *from_len, skb_frag_t **frag, u32 rem) +{ + u32 copied = 0; + + while (1) { + u32 copy_len = min_t(u32, *from_len, to_len); + + memcpy(to, *from, copy_len); + copied += copy_len; + if (rem == copied) + return copied; + + if (*from_len == copy_len) { + *from = skb_frag_address(*frag); + *from_len = skb_frag_size((*frag)++); + } else { + *from += copy_len; + *from_len -= copy_len; + } + if (to_len == copy_len) + return copied; - memcpy(to_buf, from_buf, len + metalen); + to_len -= copy_len; + to += copy_len; + } } static int __xsk_rcv(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) { + u32 frame_size = xsk_pool_get_rx_frame_size(xs->pool); + void *copy_from = xsk_copy_xdp_start(xdp), *copy_to; + u32 from_len, meta_len, rem, num_desc; struct xdp_buff_xsk *xskb; struct xdp_buff *xsk_xdp; - int err; + skb_frag_t *frag; + + from_len = xdp->data_end - copy_from; + meta_len = xdp->data - copy_from; + rem = len + meta_len; + + if (len <= frame_size && !xdp_buff_has_frags(xdp)) { + int err; - xsk_xdp = xsk_buff_alloc(xs->pool); - if (!xsk_xdp) { + xsk_xdp = xsk_buff_alloc(xs->pool); + if (!xsk_xdp) { + xs->rx_dropped++; + return -ENOMEM; + } + memcpy(xsk_xdp->data - meta_len, copy_from, rem); + xskb = container_of(xsk_xdp, struct xdp_buff_xsk, xdp); + err = __xsk_rcv_zc(xs, xskb, len, 0); + if (err) { + xsk_buff_free(xsk_xdp); + return err; + } + + return 0; + } + + num_desc = (len - 1) / frame_size + 1; + + if (!xsk_buff_can_alloc(xs->pool, num_desc)) { xs->rx_dropped++; return -ENOMEM; } + if (xskq_prod_nb_free(xs->rx, num_desc) < num_desc) { + xs->rx_queue_full++; + return -ENOBUFS; + } - xsk_copy_xdp(xsk_xdp, xdp, len); - xskb = container_of(xsk_xdp, struct xdp_buff_xsk, xdp); - err = __xsk_rcv_zc(xs, xskb, len, 0); - if (err) { - xsk_buff_free(xsk_xdp); - return err; + if (xdp_buff_has_frags(xdp)) { + struct skb_shared_info *sinfo; + + sinfo = xdp_get_shared_info_from_buff(xdp); + frag = &sinfo->frags[0]; } + + do { + u32 to_len = frame_size + meta_len; + u32 copied; + + xsk_xdp = xsk_buff_alloc(xs->pool); + copy_to = xsk_xdp->data - meta_len; + + copied = xsk_copy_xdp(copy_to, ©_from, to_len, &from_len, &frag, rem); + rem -= copied; + + xskb = container_of(xsk_xdp, struct xdp_buff_xsk, xdp); + __xsk_rcv_zc(xs, xskb, copied - meta_len, rem ? XDP_PKT_CONTD : 0); + meta_len = 0; + } while (rem); + return 0; } @@ -225,7 +289,7 @@ static int xsk_rcv_check(struct xdp_sock *xs, struct xdp_buff *xdp, u32 len) if (xs->dev != xdp->rxq->dev || xs->queue_id != xdp->rxq->queue_index) return -EINVAL; - if (len > xsk_pool_get_rx_frame_size(xs->pool)) { + if (len > xsk_pool_get_rx_frame_size(xs->pool) && !xs->sg) { xs->rx_dropped++; return -ENOSPC; }