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 6011AC46467 for ; Tue, 27 Dec 2022 07:32:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229789AbiL0Hcj (ORCPT ); Tue, 27 Dec 2022 02:32:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46062 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229626AbiL0Hci (ORCPT ); Tue, 27 Dec 2022 02:32:38 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 56F8B1099 for ; Mon, 26 Dec 2022 23:31:51 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1672126310; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=W2wV9Ru15RgYIMf7o5N9UF6E1LS25n2e/R46tB7Xi3k=; b=fDClC37AP9wLdlfd4PSUG5ly7pN41j8XExAfk0xqcYwMurvQ3QVUzDWR9xUziMw/+maWWm te/86Tn0UBlaXgRorOJAlqkj0Qq+jTyMEUA3FrSaqRX0FCUNsmUS0B+ErmvChxckf8NsjG 6nCYfac7BkyrUYV5XnVvar7IQvMjGcs= Received: from mail-pj1-f71.google.com (mail-pj1-f71.google.com [209.85.216.71]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-151-Zw2qAF4SPj2QM21GuWJ65A-1; Tue, 27 Dec 2022 02:31:48 -0500 X-MC-Unique: Zw2qAF4SPj2QM21GuWJ65A-1 Received: by mail-pj1-f71.google.com with SMTP id l21-20020a17090aec1500b00225e3da1786so1888330pjy.7 for ; Mon, 26 Dec 2022 23:31:48 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:in-reply-to:from:references:cc:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=W2wV9Ru15RgYIMf7o5N9UF6E1LS25n2e/R46tB7Xi3k=; b=NacAcR13RyCZRLrA7oKctqIi07Rj/XJtDGvIIxYiegjV+m4ERatutgoo/W8zwQav8s hQUFDEvrmi/HZmtow5ZUw0DE6SaaqngHraumoqZXbt0WE6qxn18+bVCuY432a7dVnv7F XWnbRK+QSVwS0QvoMcnjCT0HLVjM9yc3gIjHe2xO2EO5t3+DeNkZlm9CfB8U1KeMgOCl emuq6xTnVvpOY3yEf3oDme0yfge7p6hrxIU6KUGL3MtsVOhD4USMqFvjfBGxVzVyW6o9 P3AdPHqmvh0wkacLxE3jD42KKiwa/WEnBKt7Bj4aX9BGz0/xm7fZ21zpoV+0kONfMZ0p VDng== X-Gm-Message-State: AFqh2kpA21KyIegO+YWJalQh2IZSrApMMBZcclVDoMgxlvOE9mqWOMfw xTt5GtI55dufu0kTnLZLSkHuek8Ag2yGxoJ5n7Pv4+r0r+e0/eho+Kp5NLRKoHpCqXipgVgzXIv ZEP9RughEUwOZkw+Y X-Received: by 2002:a17:90b:3793:b0:226:744:d46a with SMTP id mz19-20020a17090b379300b002260744d46amr2138842pjb.41.1672126307781; Mon, 26 Dec 2022 23:31:47 -0800 (PST) X-Google-Smtp-Source: AMrXdXud3ceh+S6ptBkVdEfki5fg6mqgyU/IgMImjqfqcDI/5201CA5WG4A1Z2qhWnLktdN82iHPyA== X-Received: by 2002:a17:90b:3793:b0:226:744:d46a with SMTP id mz19-20020a17090b379300b002260744d46amr2138825pjb.41.1672126307511; Mon, 26 Dec 2022 23:31:47 -0800 (PST) Received: from [10.72.13.143] ([43.228.180.230]) by smtp.gmail.com with ESMTPSA id mm2-20020a17090b358200b0021937b2118bsm10070935pjb.54.2022.12.26.23.31.43 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 26 Dec 2022 23:31:47 -0800 (PST) Message-ID: <9d049351-11c8-2178-c88c-6d4496df773e@redhat.com> Date: Tue, 27 Dec 2022 15:31:41 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.6.1 Subject: Re: [PATCH v2 7/9] virtio_net: build skb from multi-buffer xdp Content-Language: en-US To: Heng Qi , netdev@vger.kernel.org, bpf@vger.kernel.org Cc: "Michael S . Tsirkin" , Paolo Abeni , Jakub Kicinski , John Fastabend , "David S . Miller" , Daniel Borkmann , Alexei Starovoitov , Eric Dumazet , Xuan Zhuo References: <20221220141449.115918-1-hengqi@linux.alibaba.com> <20221220141449.115918-8-hengqi@linux.alibaba.com> From: Jason Wang In-Reply-To: <20221220141449.115918-8-hengqi@linux.alibaba.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org 在 2022/12/20 22:14, Heng Qi 写道: > This converts the xdp_buff directly to a skb, including > multi-buffer and single buffer xdp. We'll isolate the > construction of skb based on xdp from page_to_skb(). > > Signed-off-by: Heng Qi > Reviewed-by: Xuan Zhuo > --- > drivers/net/virtio_net.c | 50 ++++++++++++++++++++++++++++++++++++++++ > 1 file changed, 50 insertions(+) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 9f31bfa7f9a6..4e12196fcfd4 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -948,6 +948,56 @@ static struct sk_buff *receive_big(struct net_device *dev, > return NULL; > } > > +/* Why not use xdp_build_skb_from_frame() ? > + * XDP core assumes that xdp frags are PAGE_SIZE in length, while in > + * virtio-net there are 2 points that do not match its requirements: > + * 1. The size of the prefilled buffer is not fixed before xdp is set. > + * 2. When xdp is loaded, virtio-net has a hole mechanism (refer to > + * add_recvbuf_mergeable()), which will make the size of a buffer > + * exceed PAGE_SIZE. Is point 2 still valid after patch 1? Other than this: Acked-by: Jason Wang Thanks > + */ > +static struct sk_buff *build_skb_from_xdp_buff(struct net_device *dev, > + struct virtnet_info *vi, > + struct xdp_buff *xdp, > + unsigned int xdp_frags_truesz) > +{ > + struct skb_shared_info *sinfo = xdp_get_shared_info_from_buff(xdp); > + unsigned int headroom, data_len; > + struct sk_buff *skb; > + int metasize; > + u8 nr_frags; > + > + if (unlikely(xdp->data_end > xdp_data_hard_end(xdp))) { > + pr_debug("Error building skb as missing reserved tailroom for xdp"); > + return NULL; > + } > + > + if (unlikely(xdp_buff_has_frags(xdp))) > + nr_frags = sinfo->nr_frags; > + > + skb = build_skb(xdp->data_hard_start, xdp->frame_sz); > + if (unlikely(!skb)) > + return NULL; > + > + headroom = xdp->data - xdp->data_hard_start; > + data_len = xdp->data_end - xdp->data; > + skb_reserve(skb, headroom); > + __skb_put(skb, data_len); > + > + metasize = xdp->data - xdp->data_meta; > + metasize = metasize > 0 ? metasize : 0; > + if (metasize) > + skb_metadata_set(skb, metasize); > + > + if (unlikely(xdp_buff_has_frags(xdp))) > + xdp_update_skb_shared_info(skb, nr_frags, > + sinfo->xdp_frags_size, > + xdp_frags_truesz, > + xdp_buff_is_frag_pfmemalloc(xdp)); > + > + return skb; > +} > + > /* TODO: build xdp in big mode */ > static int virtnet_build_xdp_buff_mrg(struct net_device *dev, > struct virtnet_info *vi,