From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ferruh Yigit <ferruh.yigit@intel.com>
Subject: Re: [PATCH v1 1/6] net/af_xdp: introduce AF_XDP PMD
	driver
Date: Wed, 13 Mar 2019 10:54:10 +0000
Message-ID: <dadc9cb2-9227-6374-af4e-717219c5f61f@intel.com>
References: <20190301080947.91086-1-xiaolong.ye@intel.com>
 <20190301080947.91086-2-xiaolong.ye@intel.com>
 <c59bdd6a-3c84-08cc-b244-a7d31a595b10@intel.com>
 <20190312155430.GC46228@intel.com>
Mime-Version: 1.0
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: 8bit
Cc: dev@dpdk.org, Qi Zhang <qi.z.zhang@intel.com>
To: Ye Xiaolong <xiaolong.ye@intel.com>
Return-path: <dev-bounces@dpdk.org>
Received: from mga02.intel.com (mga02.intel.com [134.134.136.20])
 by dpdk.org (Postfix) with ESMTP id 545704C96
 for <dev@dpdk.org>; Wed, 13 Mar 2019 11:54:17 +0100 (CET)
In-Reply-To: <20190312155430.GC46228@intel.com>
Content-Language: en-US
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>


>> <...>
>>
>>> +Prerequisites
>>> +-------------
>>> +
>>> +This is a Linux-specific PMD, thus the following prerequisites apply:
>>> +
>>> +*  A Linux Kernel with XDP sockets configuration enabled;
>>
>> Can you please give more details of what exact vanilla kernel version?
> 
> Do you mean I should write more details about AF_XDP in kernel in this introduction 
> document?

I think it is good to document the exact version information instead of saying
"Linux Kernel with af_xdp".

>>> +*  libbpf with latest af_xdp support installed
>>
>> Is there a specific version of libbpf for this?
> 
> I'm not aware that there is specific version number for libbpf, it's part of linux
> kernel src code.

If it is coming with Linux kernel, which version of Linux kernel?

>> <...>
>>
>>> +
>>> +#include <linux/if_ether.h>
>>> +#include <linux/if_xdp.h>
>>> +#include <linux/if_link.h>
>>> +#include <asm/barrier.h>
>>
>> Getting an build error for this [1], can there be any include path param missing?
>>
>> [1]
>> drivers/net/af_xdp/rte_eth_af_xdp.c:15:10: fatal error: asm/barrier.h: No such
>> file or directory
> 
> Yes, it need something like 
> 
> CFLAGS += -I/root/yexl/shared_mks0/linux/tools/include
> 
> as in above Makefile currently.

I see, assuming you will be booting up with that kernel, can something like
below work:

CFLAGS += -I/lib/modules/$(shell uname -r)/build/tools/include/

>> <...>
>>
>>> +static void
>>> +eth_dev_info(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info)
>>> +{
>>> +	struct pmd_internals *internals = dev->data->dev_private;
>>> +
>>> +	dev_info->if_index = internals->if_index;
>>> +	dev_info->max_mac_addrs = 1;
>>> +	dev_info->max_rx_pktlen = (uint32_t)ETH_FRAME_LEN;
>>> +	dev_info->max_rx_queues = 1;
>>> +	dev_info->max_tx_queues = 1;
>>
>> 'ETH_AF_XDP_MAX_QUEUE_PAIRS' is '16' but you are forcing the max Rx/Tx queue
>> number to be '1', intentional?
> 
> Yes, current implementation is single queue only, we plan to support muli-queues
> in futher.

OK, Can you please document this information?