From mboxrd@z Thu Jan 1 00:00:00 1970 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 8A3F7C4167B for ; Mon, 26 Dec 2022 02:33:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229572AbiLZCdC (ORCPT ); Sun, 25 Dec 2022 21:33:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37424 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229560AbiLZCdB (ORCPT ); Sun, 25 Dec 2022 21:33:01 -0500 Received: from out30-56.freemail.mail.aliyun.com (out30-56.freemail.mail.aliyun.com [115.124.30.56]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48E272674; Sun, 25 Dec 2022 18:32:59 -0800 (PST) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R611e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018046049;MF=hengqi@linux.alibaba.com;NM=1;PH=DS;RN=12;SR=0;TI=SMTPD_---0VY1b5S1_1672021975; Received: from 30.39.209.91(mailfrom:hengqi@linux.alibaba.com fp:SMTPD_---0VY1b5S1_1672021975) by smtp.aliyun-inc.com; Mon, 26 Dec 2022 10:32:56 +0800 Message-ID: Date: Mon, 26 Dec 2022 10:32:53 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:108.0) Gecko/20100101 Thunderbird/108.0 Subject: Re: [PATCH v2 0/9] virtio_net: support multi buffer xdp From: Heng Qi To: Jason Wang Cc: "Michael S . Tsirkin" , Paolo Abeni , Jakub Kicinski , John Fastabend , "David S . Miller" , Daniel Borkmann , Alexei Starovoitov , Eric Dumazet , Xuan Zhuo , netdev@vger.kernel.org, bpf@vger.kernel.org References: <20221220141449.115918-1-hengqi@linux.alibaba.com> In-Reply-To: <20221220141449.115918-1-hengqi@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Hi Jason, do you have any comments on this? Thanks. 在 2022/12/20 下午10:14, Heng Qi 写道: > 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 | 332 ++++++++++++++++++++++++++------------- > 1 file changed, 219 insertions(+), 113 deletions(-) >