From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: <stable-bounces@dpdk.org> Received: from dpdk.org (dpdk.org [92.243.14.124]) by inbox.dpdk.org (Postfix) with ESMTP id 31F07A2EFC for <public@inbox.dpdk.org>; Tue, 15 Oct 2019 10:14:32 +0200 (CEST) Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id 018D91D453; Tue, 15 Oct 2019 10:14:32 +0200 (CEST) Received: from dispatch1-us1.ppe-hosted.com (dispatch1-us1.ppe-hosted.com [148.163.129.52]) by dpdk.org (Postfix) with ESMTP id 910031D44B; Tue, 15 Oct 2019 10:14:28 +0200 (CEST) X-Virus-Scanned: Proofpoint Essentials engine Received: from webmail.solarflare.com (uk.solarflare.com [193.34.186.16]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-SHA384 (256/256 bits)) (No client certificate requested) by mx1-us1.ppe-hosted.com (PPE Hosted ESMTP Server) with ESMTPS id C1DF4940064; Tue, 15 Oct 2019 08:14:26 +0000 (UTC) Received: from [192.168.38.17] (91.220.146.112) by ukex01.SolarFlarecom.com (10.17.10.4) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Tue, 15 Oct 2019 09:14:19 +0100 To: Tiwei Bie <tiwei.bie@intel.com> CC: Marvin Liu <yong.liu@intel.com>, <maxime.coquelin@redhat.com>, <zhihong.wang@intel.com>, <stephen@networkplumber.org>, <dev@dpdk.org>, <stable@dpdk.org>, Kevin Traynor <ktraynor@redhat.com>, Luca Boccassi <bluca@debian.org> References: <20190923140511.107939-1-yong.liu@intel.com> <ea94171a-ef64-6909-a976-388b8fadc7e2@solarflare.com> <20191015053309.GA18809@___> From: Andrew Rybchenko <arybchenko@solarflare.com> Message-ID: <62ccfe11-9302-2b2f-13c3-87cc37b172fb@solarflare.com> Date: Tue, 15 Oct 2019 11:14:15 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:60.0) Gecko/20100101 Thunderbird/60.9.0 MIME-Version: 1.0 In-Reply-To: <20191015053309.GA18809@___> Content-Type: text/plain; charset="utf-8"; format=flowed Content-Transfer-Encoding: 7bit Content-Language: en-GB X-Originating-IP: [91.220.146.112] X-ClientProxiedBy: ocex03.SolarFlarecom.com (10.20.40.36) To ukex01.SolarFlarecom.com (10.17.10.4) X-TM-AS-Product-Ver: SMEX-12.5.0.1300-8.5.1010-24978.003 X-TM-AS-Result: No-11.146100-8.000000-10 X-TMASE-MatchedRID: byfwvk+IcRnmLzc6AOD8DfHkpkyUphL9SeIjeghh/zMdQW9W2F3v/ciT Wug2C4DNBTL3N8yyT9ePQi9XuOWoOGzj1zlNQsvv4jRkIImnX0NfAXPuWnqbj7t0cvfchz7yRzs TPtipeqrodd+2IFCZpqJZALSXBkSFpUxzcSQ8HaTwqDryy7bDITB4tWHctlhIw62uSG5kL1aj1Z rjLTOfz2j8uEoo2xGh/Eml6Vez+EoNKzHdZvkNCRIRh9wkXSlFu8ZgmQ167rWsBbMjHUED8Ozn6 eE2grwnDV46xym6Sorq2PGDWaqIuyzB69I7dfoFzfqlpbtmcWhRvgR0hkbG4PyQXCBzKijhUKnZ C4CXj7eKK7oqyLhtj15vbElLXtAv7/9r2G5AnUSeAiCmPx4NwLTrdaH1ZWqCZYJ9vPJ1vSDiaBc E8wFw3o2j49Ftap9EOwBXM346/+zUhDM9xFHZ3QXnRKjI6XUoYqzWZX6DQqpqolFKk2ksSdELrs isNJZW X-TM-AS-User-Approved-Sender: Yes X-TM-AS-User-Blocked-Sender: No X-TMASE-Result: 10--11.146100-8.000000 X-TMASE-Version: SMEX-12.5.0.1300-8.5.1010-24978.003 X-MDID: 1571127267-c0PFkGaEKt9Y Subject: Re: [dpdk-stable] [dpdk-dev] [PATCH] net/virtio: fix mbuf data and pkt length mismatch X-BeenThere: stable@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches for DPDK stable branches <stable.dpdk.org> List-Unsubscribe: <https://mails.dpdk.org/options/stable>, <mailto:stable-request@dpdk.org?subject=unsubscribe> List-Archive: <http://mails.dpdk.org/archives/stable/> List-Post: <mailto:stable@dpdk.org> List-Help: <mailto:stable-request@dpdk.org?subject=help> List-Subscribe: <https://mails.dpdk.org/listinfo/stable>, <mailto:stable-request@dpdk.org?subject=subscribe> Errors-To: stable-bounces@dpdk.org Sender: "stable" <stable-bounces@dpdk.org> Hi Tiwei, On 10/15/19 8:33 AM, Tiwei Bie wrote: > On Mon, Oct 14, 2019 at 06:15:42PM +0300, Andrew Rybchenko wrote: >>> diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c >>> index 27ead19fb..822cce06d 100644 >>> --- a/drivers/net/virtio/virtio_rxtx.c >>> +++ b/drivers/net/virtio/virtio_rxtx.c >>> @@ -597,9 +597,8 @@ virtqueue_enqueue_xmit_inorder(struct virtnet_tx *txvq, >>> dxp->cookie = (void *)cookies[i]; >>> dxp->ndescs = 1; >>> - hdr = (struct virtio_net_hdr *) >>> - rte_pktmbuf_prepend(cookies[i], head_size); >>> - cookies[i]->pkt_len -= head_size; >>> + hdr = (struct virtio_net_hdr *)(char *)cookies[i]->buf_addr + >>> + cookies[i]->data_off - head_size; >>> /* if offload disabled, hdr is not zeroed yet, do it now */ >>> if (!vq->hw->has_tx_offload) >>> @@ -608,9 +607,10 @@ virtqueue_enqueue_xmit_inorder(struct virtnet_tx *txvq, >>> virtqueue_xmit_offload(hdr, cookies[i], true); >>> start_dp[idx].addr = VIRTIO_MBUF_DATA_DMA_ADDR(cookies[i], vq); >> As I understand the problem is here. It points to start of the packet >> (Ethernet header) since data_off is not changed above now, but >> should point to virtio_net_hdr before the packet. >> >> I think the patch fixes the bug in a wrong direction. It looks better >> to simply remove >> >> cookies[i]->pkt_len -= head_size; >> >> above and care about real packet length difference in >> virtio_update_packet_stats() or when it is called from Tx path. >> >> If it is OK for maintainers I'm ready to send patches to rollback back >> this one and fix it as described above. > Hi Andrew, > > Thanks for looking into this! Feel free to send your fix. > PS. Another thing also needs to be noticed is that, after > prepending the net hdr with rte_pktmbuf_prepend(), below > code in virtio_update_packet_stats() won't be able to > access the ether header as expected: > > https://github.com/DPDK/dpdk/blob/31b798a6f08e9b333b94b8bb26910209aa810b73/drivers/net/virtio/virtio_rxtx.c#L134-L140 Thanks for the information. Looking closer I've changed my mind. Will send patch shortly. Andrew.