From mboxrd@z Thu Jan  1 00:00:00 1970
From: Stephen Hemminger <stephen@networkplumber.org>
Subject: Re: Question about jumbo frame support on ixgbe
Date: Wed, 31 Oct 2018 08:48:36 -0700
Message-ID: <20181031084836.0e3bea7f@xeon-e3>
References: <20181031144907.303203-1-yong.liu@intel.com>
 <201810310822.w9V8MaA1017463@ccmail04.silk.ntt-tx.co.jp>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Cc: dev@dpdk.org
To: Hideyuki Yamashita <yamashita.hideyuki@po.ntt-tx.co.jp>
Return-path: <dev-bounces@dpdk.org>
Received: from mail-pf1-f177.google.com (mail-pf1-f177.google.com
 [209.85.210.177]) by dpdk.org (Postfix) with ESMTP id 8BEF7F94
 for <dev@dpdk.org>; Wed, 31 Oct 2018 16:48:45 +0100 (CET)
Received: by mail-pf1-f177.google.com with SMTP id a15-v6so7832055pfn.0
 for <dev@dpdk.org>; Wed, 31 Oct 2018 08:48:45 -0700 (PDT)
In-Reply-To: <201810310822.w9V8MaA1017463@ccmail04.silk.ntt-tx.co.jp>
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://mails.dpdk.org/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://mails.dpdk.org/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <https://mails.dpdk.org/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

On Wed, 31 Oct 2018 17:22:02 +0900
Hideyuki Yamashita <yamashita.hideyuki@po.ntt-tx.co.jp> wrote:

> Hi, 
> 
> I have a very basic question about jumbo frame support for ixgbe.
> 
> I understand that some drivers support jumbo frame and 
> if it receive jumbo packet (greater than 1500 byte), it creates
> mbuf chains and pass it to DPDK application through 
> e.g. rte_eth_rx_burst.
> 
> However it looks that ixgbe driver does not support jumbo frame.
> 
> Q1. Is my understanding above correct?
> Q2. If A1 equals YES, then are there any future plan to support 
> jumbo frame on ixgbe?
> 
> BR,
> Hideyuki Yamashita
> NTT TechnoCross
> 

I don't work for Intel, and haven't tried jumbo frames on ixgbe.
The hardware does support jumbo frames.
You might be confusing the overlapping receive offload values.

The setting for using jumbo frames is in current DPDK is shown
as available in device as:
	rx_offload_capa & DEV_RX_OFFLOAD_JUMBO_FRAME
In order to use it, this bit must be setn in rx_conf that
is passed to rte_eth_rx_queue_setup


The feature bit that creates multiple mbuf's if necessary on
receive is:
	rx_offload_capa  & DEV_RX_OFFLOAD_SCATTER
Likewise to enable it, this must be set in rte_eth_rx_queue_setup
rx_conf.