From patchwork Wed Oct 25 02:54:53 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Wenzhuo Lu X-Patchwork-Id: 30843 X-Patchwork-Delegate: ferruh.yigit@amd.com Return-Path: X-Original-To: patchwork@dpdk.org Delivered-To: patchwork@dpdk.org Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id CE61F1B813; Wed, 25 Oct 2017 04:53:36 +0200 (CEST) Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by dpdk.org (Postfix) with ESMTP id D26231B80E for ; Wed, 25 Oct 2017 04:53:35 +0200 (CEST) Received: from orsmga005.jf.intel.com ([10.7.209.41]) by orsmga103.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 24 Oct 2017 19:53:34 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.43,430,1503385200"; d="scan'208";a="164590356" Received: from dpdk26.sh.intel.com ([10.67.110.152]) by orsmga005.jf.intel.com with ESMTP; 24 Oct 2017 19:53:33 -0700 From: Wenzhuo Lu To: dev@dpdk.org Cc: Wenzhuo Lu Date: Wed, 25 Oct 2017 10:54:53 +0800 Message-Id: <1508900093-9894-1-git-send-email-wenzhuo.lu@intel.com> X-Mailer: git-send-email 1.9.3 Subject: [dpdk-dev] [PATCH] doc: more clarification for i40e 16 bytes desc X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" The description of i40e 16 bytes descriptor is not clear enough. Add more details. Signed-off-by: Wenzhuo Lu --- doc/guides/nics/i40e.rst | 11 +++++++++-- 1 file changed, 9 insertions(+), 2 deletions(-) diff --git a/doc/guides/nics/i40e.rst b/doc/guides/nics/i40e.rst index a0946e6..e0237a8 100644 --- a/doc/guides/nics/i40e.rst +++ b/doc/guides/nics/i40e.rst @@ -398,13 +398,20 @@ used to classify MPLS packet by using a command in testpmd like: testpmd> ethertype_filter 0 add mac_ignr 00:00:00:00:00:00 ethertype \ 0x8847 fwd queue -16 Byte Descriptor cannot be used on DPDK VF -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +16 Bytes Descriptor setting on DPDK VF +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Until 2.1.26, the Linux i40e driver doesn't support 16 bytes RX descriptor. If the Linux i40e kernel driver is used as host driver, while DPDK i40e PMD is used as the VF driver, DPDK cannot choose 16 byte receive descriptor. That is to say, user should keep ``CONFIG_RTE_LIBRTE_I40E_16BYTE_RX_DESC=n`` in config file. +In the future, if the Linux i40e driver supports 16 bytes RX descriptor, user +should make sure the DPDK VF uses the same RX descriptor mode, 16 bytes or 32 +bytes, as the PF driver. + +The same rule for DPDK PF + DPDK VF. The PF and VF should use the same RX +descriptor mode. Or the VF RX will not work. Receive packets with Ethertype 0x88A8 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~