From patchwork Tue Jan 3 06:40:03 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Heng Qi X-Patchwork-Id: 13087211 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8207FC53210 for ; Tue, 3 Jan 2023 06:40:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232939AbjACGkU (ORCPT ); Tue, 3 Jan 2023 01:40:20 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59640 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230254AbjACGkT (ORCPT ); Tue, 3 Jan 2023 01:40:19 -0500 Received: from out30-6.freemail.mail.aliyun.com (out30-6.freemail.mail.aliyun.com [115.124.30.6]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 823361088; Mon, 2 Jan 2023 22:40:17 -0800 (PST) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R431e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045168;MF=hengqi@linux.alibaba.com;NM=1;PH=DS;RN=12;SR=0;TI=SMTPD_---0VYiqoEI_1672728012; Received: from localhost(mailfrom:hengqi@linux.alibaba.com fp:SMTPD_---0VYiqoEI_1672728012) by smtp.aliyun-inc.com; Tue, 03 Jan 2023 14:40:13 +0800 From: Heng Qi To: netdev@vger.kernel.org, bpf@vger.kernel.org Cc: Jason Wang , "Michael S . Tsirkin" , Paolo Abeni , Jakub Kicinski , John Fastabend , "David S . Miller" , Daniel Borkmann , Alexei Starovoitov , Eric Dumazet , Xuan Zhuo Subject: [PATCH v3 0/9] virtio-net: support multi buffer xdp Date: Tue, 3 Jan 2023 14:40:03 +0800 Message-Id: <20230103064012.108029-1-hengqi@linux.alibaba.com> X-Mailer: git-send-email 2.19.1.6.gb485710b MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Changes since PATCH v2: - Even if single buffer xdp has a hole mechanism, there will be no problem (limiting mtu and turning off GUEST GSO), so there is no need to backport "[PATCH 1/9]"; - Modify calculation of MTU for single buffer xdp in virtnet_xdp_set(); - Make truesize in mergeable mode return to literal meaning; - Add some comments for legibility; Changes since RFC: - Using headroom instead of vi->xdp_enabled to avoid re-reading in add_recvbuf_mergeable(); - Disable GRO_HW and keep linearization for single buffer xdp; - Renamed to virtnet_build_xdp_buff_mrg(); - pr_debug() to netdev_dbg(); - Adjusted the order of the patch series. Currently, virtio net only supports xdp for single-buffer packets or linearized multi-buffer packets. This patchset supports xdp for multi-buffer packets, then larger MTU can be used if xdp sets the xdp.frags. This does not affect single buffer handling. In order to build multi-buffer xdp neatly, we integrated the code into virtnet_build_xdp_buff_mrg() for xdp. The first buffer is used for prepared xdp buff, and the rest of the buffers are added to its skb_shared_info structure. This structure can also be conveniently converted during XDP_PASS to get the corresponding skb. Since virtio net uses comp pages, and bpf_xdp_frags_increase_tail() is based on the assumption of the page pool, (rxq->frag_size - skb_frag_size(frag) - skb_frag_off(frag)) is negative in most cases. So we didn't set xdp_rxq->frag_size in virtnet_open() to disable the tail increase. Heng Qi (9): virtio-net: disable the hole mechanism for xdp virtio-net: set up xdp for multi buffer packets virtio-net: update bytes calculation for xdp_frame virtio-net: build xdp_buff with multi buffers virtio-net: construct multi-buffer xdp in mergeable virtio-net: transmit the multi-buffer xdp virtio-net: build skb from multi-buffer xdp virtio-net: remove xdp related info from page_to_skb() virtio-net: support multi-buffer xdp drivers/net/virtio_net.c | 371 ++++++++++++++++++++++++++------------- 1 file changed, 250 insertions(+), 121 deletions(-)