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 X-Spam-Level: X-Spam-Status: No, score=-13.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id D4991C11D29 for ; Fri, 21 Feb 2020 04:23:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9D1B2208E4 for ; Fri, 21 Feb 2020 04:23:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="A9BhZrLn" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729685AbgBUEX5 (ORCPT ); Thu, 20 Feb 2020 23:23:57 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:58238 "EHLO us-smtp-1.mimecast.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729595AbgBUEX5 (ORCPT ); Thu, 20 Feb 2020 23:23:57 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582259035; 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=9uOXUdcAkm4uECVzyjBcZ9Jj9pBC2hIUjFUbk2PSZpc=; b=A9BhZrLno2l0icEoErsgfsfQY64MMlHgSZGeWpxGXkPrQBkq6jS3sUvJ+DyPdNPl7lsPEv DLHiZLVf94Acum543A6pjHYz+nNJhOnzJuOF8pa8xxcUlYqKJgkNt8hR+76KLGwBT7V2TI 4CpF277nT0Ok4zKb9mmiEcjS/ZnGlbw= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-292-iZ-dekTJOpmppp2BwkCNNA-1; Thu, 20 Feb 2020 23:23:47 -0500 X-MC-Unique: iZ-dekTJOpmppp2BwkCNNA-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id EE0BF189F766; Fri, 21 Feb 2020 04:23:44 +0000 (UTC) Received: from [10.72.13.208] (ovpn-13-208.pek2.redhat.com [10.72.13.208]) by smtp.corp.redhat.com (Postfix) with ESMTP id A82835DA76; Fri, 21 Feb 2020 04:23:33 +0000 (UTC) Subject: Re: [PATCH bpf-next v5] virtio_net: add XDP meta data support To: Yuya Kusakabe Cc: andriin@fb.com, ast@kernel.org, bpf@vger.kernel.org, daniel@iogearbox.net, davem@davemloft.net, hawk@kernel.org, john.fastabend@gmail.com, kafai@fb.com, kuba@kernel.org, linux-kernel@vger.kernel.org, mst@redhat.com, netdev@vger.kernel.org, songliubraving@fb.com, yhs@fb.com References: <0c5eaba2-dd5a-fc3f-0e8f-154f7ad52881@redhat.com> <20200220085549.269795-1-yuya.kusakabe@gmail.com> From: Jason Wang Message-ID: <5bf11065-6b85-8253-8548-683c01c98ac1@redhat.com> Date: Fri, 21 Feb 2020 12:23:31 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.8.0 MIME-Version: 1.0 In-Reply-To: <20200220085549.269795-1-yuya.kusakabe@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 Content-Transfer-Encoding: quoted-printable Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/2/20 =E4=B8=8B=E5=8D=884:55, Yuya Kusakabe wrote: > Implement support for transferring XDP meta data into skb for > virtio_net driver; before calling into the program, xdp.data_meta point= s > to xdp.data, where on program return with pass verdict, we call > into skb_metadata_set(). > > Tested with the script at > https://github.com/higebu/virtio_net-xdp-metadata-test. > > Fixes: de8f3a83b0a0 ("bpf: add meta pointer for direct access") I'm not sure this is correct since virtio-net claims to not support=20 metadata by calling xdp_set_data_meta_invalid()? > Signed-off-by: Yuya Kusakabe > --- > v5: > - page_to_skb(): copy vnet header if hdr_valid without checking metas= ize. > - receive_small(): do not copy vnet header if xdp_prog is availavle. > - __virtnet_xdp_xmit_one(): remove the xdp_set_data_meta_invalid(). > - improve comments. > v4: > - improve commit message > v3: > - fix preserve the vnet header in receive_small(). > v2: > - keep copy untouched in page_to_skb(). > - preserve the vnet header in receive_small(). > - fix indentation. > --- > drivers/net/virtio_net.c | 54 ++++++++++++++++++++++++---------------= - > 1 file changed, 33 insertions(+), 21 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 2fe7a3188282..4ea0ae60c000 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -371,7 +371,7 @@ static struct sk_buff *page_to_skb(struct virtnet_i= nfo *vi, > struct receive_queue *rq, > struct page *page, unsigned int offset, > unsigned int len, unsigned int truesize, > - bool hdr_valid) > + bool hdr_valid, unsigned int metasize) > { > struct sk_buff *skb; > struct virtio_net_hdr_mrg_rxbuf *hdr; > @@ -393,6 +393,7 @@ static struct sk_buff *page_to_skb(struct virtnet_i= nfo *vi, > else > hdr_padded_len =3D sizeof(struct padded_vnet_hdr); > =20 > + /* hdr_valid means no XDP, so we can copy the vnet header */ > if (hdr_valid) > memcpy(hdr, p, hdr_len); > =20 > @@ -405,6 +406,11 @@ static struct sk_buff *page_to_skb(struct virtnet_= info *vi, > copy =3D skb_tailroom(skb); > skb_put_data(skb, p, copy); > =20 > + if (metasize) { > + __skb_pull(skb, metasize); > + skb_metadata_set(skb, metasize); > + } > + > len -=3D copy; > offset +=3D copy; > =20 > @@ -450,10 +456,6 @@ static int __virtnet_xdp_xmit_one(struct virtnet_i= nfo *vi, > struct virtio_net_hdr_mrg_rxbuf *hdr; > int err; > =20 > - /* virtqueue want to use data area in-front of packet */ > - if (unlikely(xdpf->metasize > 0)) > - return -EOPNOTSUPP; > - > if (unlikely(xdpf->headroom < vi->hdr_len)) > return -EOVERFLOW; > =20 > @@ -644,6 +646,7 @@ static struct sk_buff *receive_small(struct net_dev= ice *dev, > unsigned int delta =3D 0; > struct page *xdp_page; > int err; > + unsigned int metasize =3D 0; > =20 > len -=3D vi->hdr_len; > stats->bytes +=3D len; > @@ -683,8 +686,8 @@ static struct sk_buff *receive_small(struct net_dev= ice *dev, > =20 > xdp.data_hard_start =3D buf + VIRTNET_RX_PAD + vi->hdr_len; > xdp.data =3D xdp.data_hard_start + xdp_headroom; > - xdp_set_data_meta_invalid(&xdp); > xdp.data_end =3D xdp.data + len; > + xdp.data_meta =3D xdp.data; > xdp.rxq =3D &rq->xdp_rxq; > orig_data =3D xdp.data; > act =3D bpf_prog_run_xdp(xdp_prog, &xdp); > @@ -695,6 +698,7 @@ static struct sk_buff *receive_small(struct net_dev= ice *dev, > /* Recalculate length in case bpf program changed it */ > delta =3D orig_data - xdp.data; > len =3D xdp.data_end - xdp.data; > + metasize =3D xdp.data - xdp.data_meta; > break; > case XDP_TX: > stats->xdp_tx++; > @@ -735,11 +739,14 @@ static struct sk_buff *receive_small(struct net_d= evice *dev, > } > skb_reserve(skb, headroom - delta); > skb_put(skb, len); > - if (!delta) { > + if (!xdp_prog) { > buf +=3D header_offset; > memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len); > } /* keep zeroed vnet hdr since packet was changed by bpf */ I prefer to make this an independent patch and cc stable. Other looks good. Thanks > =20 > + if (metasize) > + skb_metadata_set(skb, metasize); > + > err: > return skb; > =20 > @@ -760,8 +767,8 @@ static struct sk_buff *receive_big(struct net_devic= e *dev, > struct virtnet_rq_stats *stats) > { > struct page *page =3D buf; > - struct sk_buff *skb =3D page_to_skb(vi, rq, page, 0, len, > - PAGE_SIZE, true); > + struct sk_buff *skb =3D > + page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, true, 0); > =20 > stats->bytes +=3D len - vi->hdr_len; > if (unlikely(!skb)) > @@ -793,6 +800,7 @@ static struct sk_buff *receive_mergeable(struct net= _device *dev, > unsigned int truesize; > unsigned int headroom =3D mergeable_ctx_to_headroom(ctx); > int err; > + unsigned int metasize =3D 0; > =20 > head_skb =3D NULL; > stats->bytes +=3D len - vi->hdr_len; > @@ -839,8 +847,8 @@ static struct sk_buff *receive_mergeable(struct net= _device *dev, > data =3D page_address(xdp_page) + offset; > xdp.data_hard_start =3D data - VIRTIO_XDP_HEADROOM + vi->hdr_len; > xdp.data =3D data + vi->hdr_len; > - xdp_set_data_meta_invalid(&xdp); > xdp.data_end =3D xdp.data + (len - vi->hdr_len); > + xdp.data_meta =3D xdp.data; > xdp.rxq =3D &rq->xdp_rxq; > =20 > act =3D bpf_prog_run_xdp(xdp_prog, &xdp); > @@ -848,24 +856,27 @@ static struct sk_buff *receive_mergeable(struct n= et_device *dev, > =20 > switch (act) { > case XDP_PASS: > + metasize =3D xdp.data - xdp.data_meta; > + > /* recalculate offset to account for any header > - * adjustments. Note other cases do not build an > - * skb and avoid using offset > + * adjustments and minus the metasize to copy the > + * metadata in page_to_skb(). Note other cases do not > + * build an skb and avoid using offset > */ > - offset =3D xdp.data - > - page_address(xdp_page) - vi->hdr_len; > + offset =3D xdp.data - page_address(xdp_page) - > + vi->hdr_len - metasize; > =20 > - /* recalculate len if xdp.data or xdp.data_end were > - * adjusted > + /* recalculate len if xdp.data, xdp.data_end or > + * xdp.data_meta were adjusted > */ > - len =3D xdp.data_end - xdp.data + vi->hdr_len; > + len =3D xdp.data_end - xdp.data + vi->hdr_len + metasize; > /* We can only create skb based on xdp_page. */ > if (unlikely(xdp_page !=3D page)) { > rcu_read_unlock(); > put_page(page); > - head_skb =3D page_to_skb(vi, rq, xdp_page, > - offset, len, > - PAGE_SIZE, false); > + head_skb =3D page_to_skb(vi, rq, xdp_page, offset, > + len, PAGE_SIZE, false, > + metasize); > return head_skb; > } > break; > @@ -921,7 +932,8 @@ static struct sk_buff *receive_mergeable(struct net= _device *dev, > goto err_skb; > } > =20 > - head_skb =3D page_to_skb(vi, rq, page, offset, len, truesize, !xdp_pr= og); > + head_skb =3D page_to_skb(vi, rq, page, offset, len, truesize, !xdp_pr= og, > + metasize); > curr_skb =3D head_skb; > =20 > if (unlikely(!curr_skb))