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=-20.6 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,USER_AGENT_GIT,USER_IN_DEF_DKIM_WL 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 EB6DFC433E4 for ; Tue, 21 Jul 2020 07:14:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C861C21702 for ; Tue, 21 Jul 2020 07:14:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=cisco.com header.i=@cisco.com header.b="HuJlAATZ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728476AbgGUHOJ (ORCPT ); Tue, 21 Jul 2020 03:14:09 -0400 Received: from bgl-iport-3.cisco.com ([72.163.197.27]:21915 "EHLO bgl-iport-3.cisco.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728432AbgGUHOJ (ORCPT ); Tue, 21 Jul 2020 03:14:09 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=cisco.com; i=@cisco.com; l=3137; q=dns/txt; s=iport; t=1595315647; x=1596525247; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=zvf42wHQKUkFFzF2QiNY4mJG+Y+dLfDpC7azn8w5zUQ=; b=HuJlAATZ0UHS7gaSbwOrpjkVN4p6xU0yXl/F0B4KF6+aivsS6TH4D3JW lDAqBQzfntaAHFRktyKdglhlVGJBlH3G7llEjxmF8F1LymdULY1Z2kt2+ vCJ5zYhChU6LbptkkG5IeRtGM/2pIXGkJOTX/qcM20mDB1QAcgM/gEOYO 4=; X-IronPort-AV: E=Sophos;i="5.75,378,1589241600"; d="scan'208";a="126254313" Received: from vla196-nat.cisco.com (HELO bgl-core-1.cisco.com) ([72.163.197.24]) by bgl-iport-3.cisco.com with ESMTP/TLS/DHE-RSA-SEED-SHA; 21 Jul 2020 07:14:04 +0000 Received: from SRIRAKR2-M-R0A8.cisco.com ([10.65.71.4]) by bgl-core-1.cisco.com (8.15.2/8.15.2) with ESMTP id 06L7E4SD014427; Tue, 21 Jul 2020 07:14:04 GMT From: Sriram Krishnan To: "K. Y. Srinivasan" , Haiyang Zhang , Stephen Hemminger , Wei Liu Cc: mbumgard@cisco.com, ugm@cisco.com, nimm@cisco.com, xe-linux-external@cisco.com, "David S. Miller" , Jakub Kicinski , linux-hyperv@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v4] hv_netvsc: add support for vlans in AF_PACKET mode Date: Tue, 21 Jul 2020 12:44:03 +0530 Message-Id: <20200721071404.70230-1-srirakr2@cisco.com> X-Mailer: git-send-email 2.24.0 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Auto-Response-Suppress: DR, OOF, AutoReply X-Outbound-SMTP-Client: 10.65.71.4, [10.65.71.4] X-Outbound-Node: bgl-core-1.cisco.com Sender: linux-hyperv-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-hyperv@vger.kernel.org Vlan tagged packets are getting dropped when used with DPDK that uses the AF_PACKET interface on a hyperV guest. The packet layer uses the tpacket interface to communicate the vlans information to the upper layers. On Rx path, these drivers can read the vlan info from the tpacket header but on the Tx path, this information is still within the packet frame and requires the paravirtual drivers to push this back into the NDIS header which is then used by the host OS to form the packet. This transition from the packet frame to NDIS header is currently missing hence causing the host OS to drop the all vlan tagged packets sent by the drivers that use AF_PACKET (ETH_P_ALL) such as DPDK. Here is an overview of the changes in the vlan header in the packet path: The RX path (userspace handles everything): 1. RX VLAN packet is stripped by HOST OS and placed in NDIS header 2. Guest Kernel RX hv_netvsc packets and moves VLAN info from NDIS header into kernel SKB 3. Kernel shares packets with user space application with PACKET_MMAP. The SKB VLAN info is copied to tpacket layer and indication set TP_STATUS_VLAN_VALID. 4. The user space application will re-insert the VLAN info into the frame. The TX path: 1. The user space application has the VLAN info in the frame. 2. Guest kernel gets packets from the application with PACKET_MMAP. 3. The kernel later sends the frame to the hv_netvsc driver. The only way to send VLANs is when the SKB is setup & the VLAN is is stripped from the frame. 4. TX VLAN is re-inserted by HOST OS based on the NDIS header. If it sees a VLAN in the frame the packet is dropped. Cc: xe-linux-external@cisco.com Cc: Sriram Krishnan Signed-off-by: Sriram Krishnan --- drivers/net/hyperv/netvsc_drv.c | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c index 6267f706e8ee..55cf80ed40ae 100644 --- a/drivers/net/hyperv/netvsc_drv.c +++ b/drivers/net/hyperv/netvsc_drv.c @@ -605,6 +605,29 @@ static int netvsc_xmit(struct sk_buff *skb, struct net_device *net, bool xdp_tx) *hash_info = hash; } + /* When using AF_PACKET we need to drop VLAN header from + * the frame and update the SKB to allow the HOST OS + * to transmit the 802.1Q packet + */ + if (skb->protocol == htons(ETH_P_8021Q)) { + u16 vlan_tci = 0; + skb_reset_mac_header(skb); + if (eth_type_vlan(eth_hdr(skb)->h_proto)) { + int pop_err; + pop_err = __skb_vlan_pop(skb, &vlan_tci); + if (likely(pop_err == 0)) { + __vlan_hwaccel_put_tag(skb, htons(ETH_P_8021Q), vlan_tci); + /* Update the NDIS header pkt lengths */ + packet->total_data_buflen -= VLAN_HLEN; + rndis_msg->msg_len = packet->total_data_buflen; + rndis_msg->msg.pkt.data_len = packet->total_data_buflen; + } else { + netdev_err(net, "Pop vlan err %x\n", pop_err); + goto drop; + } + } + } + if (skb_vlan_tag_present(skb)) { struct ndis_pkt_8021q_info *vlan; -- 2.24.0