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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham 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 230C9C06510 for ; Tue, 2 Jul 2019 08:33:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E3EBD20836 for ; Tue, 2 Jul 2019 08:33:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727010AbfGBIdj (ORCPT ); Tue, 2 Jul 2019 04:33:39 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36984 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725867AbfGBIdi (ORCPT ); Tue, 2 Jul 2019 04:33:38 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 469E030BB367; Tue, 2 Jul 2019 08:33:38 +0000 (UTC) Received: from [10.72.12.205] (ovpn-12-205.pek2.redhat.com [10.72.12.205]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6674D60C43; Tue, 2 Jul 2019 08:33:30 +0000 (UTC) Subject: Re: [PATCH bpf-next v3] virtio_net: add XDP meta data support To: Yuya Kusakabe Cc: ast@kernel.org, daniel@iogearbox.net, davem@davemloft.net, hawk@kernel.org, jakub.kicinski@netronome.com, john.fastabend@gmail.com, kafai@fb.com, mst@redhat.com, netdev@vger.kernel.org, songliubraving@fb.com, yhs@fb.com References: <32dc2f4e-4f19-4fa5-1d24-17a025a08297@gmail.com> <20190702081646.23230-1-yuya.kusakabe@gmail.com> From: Jason Wang Message-ID: Date: Tue, 2 Jul 2019 16:33:28 +0800 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.7.2 MIME-Version: 1.0 In-Reply-To: <20190702081646.23230-1-yuya.kusakabe@gmail.com> Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.49]); Tue, 02 Jul 2019 08:33:38 +0000 (UTC) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 2019/7/2 下午4:16, Yuya Kusakabe wrote: > This adds XDP meta data support to both receive_small() and > receive_mergeable(). > > Fixes: de8f3a83b0a0 ("bpf: add meta pointer for direct access") > Signed-off-by: Yuya Kusakabe > --- > 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 | 45 +++++++++++++++++++++++++++------------- > 1 file changed, 31 insertions(+), 14 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 4f3de0ac8b0b..03a1ae6fe267 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_info *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; > @@ -393,7 +393,7 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > else > hdr_padded_len = sizeof(struct padded_vnet_hdr); > > - if (hdr_valid) > + if (hdr_valid && !metasize) > memcpy(hdr, p, hdr_len); > > len -= hdr_len; > @@ -405,6 +405,11 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, > copy = skb_tailroom(skb); > skb_put_data(skb, p, copy); > > + if (metasize) { > + __skb_pull(skb, metasize); > + skb_metadata_set(skb, metasize); > + } > + > len -= copy; > offset += copy; > > @@ -644,6 +649,7 @@ static struct sk_buff *receive_small(struct net_device *dev, > unsigned int delta = 0; > struct page *xdp_page; > int err; > + unsigned int metasize = 0; > > len -= vi->hdr_len; > stats->bytes += len; > @@ -683,10 +689,13 @@ static struct sk_buff *receive_small(struct net_device *dev, > > xdp.data_hard_start = buf + VIRTNET_RX_PAD + vi->hdr_len; > xdp.data = xdp.data_hard_start + xdp_headroom; > - xdp_set_data_meta_invalid(&xdp); > xdp.data_end = xdp.data + len; > + xdp.data_meta = xdp.data; > xdp.rxq = &rq->xdp_rxq; > orig_data = xdp.data; > + /* Copy the vnet header to the front of data_hard_start to avoid > + * overwriting by XDP meta data */ > + memcpy(xdp.data_hard_start - vi->hdr_len, xdp.data - vi->hdr_len, vi->hdr_len); What happens if we have a large metadata that occupies all headroom here? Thanks > act = bpf_prog_run_xdp(xdp_prog, &xdp); > stats->xdp_packets++; > > @@ -695,9 +704,11 @@ static struct sk_buff *receive_small(struct net_device *dev, > /* Recalculate length in case bpf program changed it */ > delta = orig_data - xdp.data; > len = xdp.data_end - xdp.data; > + metasize = xdp.data - xdp.data_meta; > break; > case XDP_TX: > stats->xdp_tx++; > + xdp.data_meta = xdp.data; > xdpf = convert_to_xdp_frame(&xdp); > if (unlikely(!xdpf)) > goto err_xdp; > @@ -736,10 +747,12 @@ static struct sk_buff *receive_small(struct net_device *dev, > skb_reserve(skb, headroom - delta); > skb_put(skb, len); > if (!delta) { > - buf += header_offset; > - memcpy(skb_vnet_hdr(skb), buf, vi->hdr_len); > + memcpy(skb_vnet_hdr(skb), buf + VIRTNET_RX_PAD, vi->hdr_len); > } /* keep zeroed vnet hdr since packet was changed by bpf */ > > + if (metasize) > + skb_metadata_set(skb, metasize); > + > err: > return skb; > > @@ -760,8 +773,8 @@ static struct sk_buff *receive_big(struct net_device *dev, > struct virtnet_rq_stats *stats) > { > struct page *page = buf; > - struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, > - PAGE_SIZE, true); > + struct sk_buff *skb = > + page_to_skb(vi, rq, page, 0, len, PAGE_SIZE, true, 0); > > stats->bytes += len - vi->hdr_len; > if (unlikely(!skb)) > @@ -793,6 +806,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > unsigned int truesize; > unsigned int headroom = mergeable_ctx_to_headroom(ctx); > int err; > + unsigned int metasize = 0; > > head_skb = NULL; > stats->bytes += len - vi->hdr_len; > @@ -839,8 +853,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > data = page_address(xdp_page) + offset; > xdp.data_hard_start = data - VIRTIO_XDP_HEADROOM + vi->hdr_len; > xdp.data = data + vi->hdr_len; > - xdp_set_data_meta_invalid(&xdp); > xdp.data_end = xdp.data + (len - vi->hdr_len); > + xdp.data_meta = xdp.data; > xdp.rxq = &rq->xdp_rxq; > > act = bpf_prog_run_xdp(xdp_prog, &xdp); > @@ -852,8 +866,9 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > * adjustments. Note other cases do not build an > * skb and avoid using offset > */ > - offset = xdp.data - > - page_address(xdp_page) - vi->hdr_len; > + metasize = xdp.data - xdp.data_meta; > + offset = xdp.data - page_address(xdp_page) - > + vi->hdr_len - metasize; > > /* recalculate len if xdp.data or xdp.data_end were > * adjusted > @@ -863,14 +878,15 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > if (unlikely(xdp_page != page)) { > rcu_read_unlock(); > put_page(page); > - head_skb = page_to_skb(vi, rq, xdp_page, > - offset, len, > - PAGE_SIZE, false); > + head_skb = page_to_skb(vi, rq, xdp_page, offset, > + len, PAGE_SIZE, false, > + metasize); > return head_skb; > } > break; > case XDP_TX: > stats->xdp_tx++; > + xdp.data_meta = xdp.data; > xdpf = convert_to_xdp_frame(&xdp); > if (unlikely(!xdpf)) > goto err_xdp; > @@ -921,7 +937,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, > goto err_skb; > } > > - head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog); > + head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog, > + metasize); > curr_skb = head_skb; > > if (unlikely(!curr_skb))