打通VPP与X710网卡之间的障碍：破解未绑定之困

问题描述

软件版本 ：
vpp

网卡类型与对端设备 ：

某万兆 x710 bypass 卡对端连接测试仪

问题现象 ：

重启 vpp，x710 网卡灯不亮

vppcli 查看接口信息 :

接口状态为 error，并报 pmd-init-fail 的错误

复现方法与概率 ：

重启 vpp 就能够复现，复现概率较大

收集信息

1. vpp 配置文件中 dpdk 接口相关配置项目

dpdk
{
  uio-driver igb_uio
        dev 0000:04:00.0
        {
            name vEth0
            num-rx-desc 1024
        }
        dev 0000:04:00.1
        {
            name vEth1
            num-rx-desc 1024
        }
}

2. lspci 查看到的网卡信息

04:00.0 Ethernet controller: Intel Corporation Ethernet Controller X710 for
10GbE SFP+ (rev 02)
04:00.1 Ethernet controller: Intel Corporation Ethernet Controller X710 for
10GbE SFP+ (rev 02)

3. lspci -xxx 获取到的网卡配置空间信息

[root@localhost]# lspci -xxx -s 04:00.0
04:00.0 Ethernet controller: Intel Corporation Ethernet Controller X710 for
10GbE SFP+ (rev 02)
00: 86807215 06 04 10 00 02 00 00 02 10 00 80 00
10: 0c 00 00 db 00 00 00 00 00 00 00 00 0c 8080 db
20: 00 00 00 00 00 00 00 00 00 00 00 00 bb 15 00 00
30: 00 00 28df40 00 00 00 00 00 00 00 0b 01 00 00
40: 01 5023 c8 08 20 00 00 00 00 00 00 00 00 00 00
50: 05 7080 01 00 00 00 00 00 00 00 00 00 00 00 00
60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
70: 11 a0 8080 03 00 00 00 03 10 00 00 00 00 00 00
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
a0: 10 00 02 00 e4 8c 00 103021 09 00 435842 00
b0: 40 00 4310 00 00 00 00 00 00 00 00 00 00 00 00
c0: 00 00 00 00 1f 00 00 00 00 00 00 00 0e 00 00 00
d0: 01 00 1e 00 00 00 00 00 00 00 00 00 00 00 00 00
e0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
[root@localhost]# lspci -xxx -s 04:00.1
04:00.1 Ethernet controller: Intel Corporation Ethernet Controller X710 for
10GbE SFP+ (rev 02)
00: 86807215 06 04 10 00 02 00 00 02 10 00 80 00
10: 0c 00 80 da 00 00 00 00 00 00 00 00 0c 00 80 db
20: 00 00 00 00 00 00 00 00 00 00 00 00 bb 15 00 00
30: 00 00 20df40 00 00 00 00 00 00 00 0b 01 00 00
40: 01 5023 c8 08 20 00 00 00 00 00 00 00 00 00 00
50: 05 7080 01 00 00 00 00 00 00 00 00 00 00 00 00
60: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
70: 11 a0 8080 03 00 00 00 03 10 00 00 00 00 00 00
80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
90: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
a0: 10 00 02 00 e4 8c 00 103021 09 00 435842 00
b0: 40 00 4310 00 00 00 00 00 00 00 00 00 00 00 00
c0: 00 00 00 00 1f 00 00 00 00 00 00 00 0e 00 00 00
d0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
e0: 03 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
f0: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

vpp 代码分析

相关函数为 dpdk_device_setup 函数，关键代码如下：

if(xd->flags & DPDK_DEVICE_FLAG_ADMIN_UP)dpdk_device_start(xd);if(vec_len(xd->errors))goto error;return;
error:
  xd->flags |= DPDK_DEVICE_FLAG_PMD_INIT_FAIL;
  sw->flags |= VNET_SW_INTERFACE_FLAG_ERROR;

调用 dpdk_device_start 失败后会设置 xd->flags 的标志，标志问题为 pmd_init_fail 。

问题定位的初步结论

出问题的口及其 pci 号如下：

vEth0   0000:04:00.0
vEth1   0000:04:00.1

阅读代码确定，当这两个口 start 失败时会触发这个问题。读取网卡配置空间，确认配置空间内容正常，不确定失败的位置及原因。

复现方法

多次杀掉 vpp，使用 vppcli 执行 show hardware-interfaces x/x 查看报错信息！

解决计划

1. 修改 dpdk 驱动，添加 x710 驱动 log 信息，重新编译 vpp 复现问题（设置 loglevel 即可）
2. 复现后观测失败位置，排查是软件问题还是硬件问题
3. 使用 l2fwd 运行 10 次，观察是否有报错信息

扩展 log 信息

1. dpdk 设置不同 loglevel 的打印级别

相关参数：

  --log-level=<int>   Set global log level
  --log-level=<type-match>:<int>

i40e 驱动相关 log-level type：

pmd.net.i40e.init
pmd.net.i40e.driver
pmd.net.i40e.rx

2. vpp 中查看 dpdk 初始化 log 信息的命令

vppcli 中执行命令：

show log

问题！！！

vpp 中能够配置的 dpdk 参数是固定的，需要内部代码解析，不能直接设置！

解决方法：

1. 尝试使用 l2fwd 来复现问题
2. 编译带调试信息的 dpdk 库，并修改 i40e 代码，将 i40e 驱动的 log 级别调低。

第二点问题，使用如下 patch 解决：

/* If link needs to go up and it is in autoneg mode the speed is OK,
@@ -2969,6 +2985,7 @@
                            &oes->tx_errors, &nes->tx_errors);
        vsi->offset_loaded = true;
@@ -12895,10 +12915,10 @@
 {
        i40e_logtype_init = rte_log_register("pmd.net.i40e.init");
        if (i40e_logtype_init >= 0)
-               rte_log_set_level(i40e_logtype_init, RTE_LOG_NOTICE);
+               rte_log_set_level(i40e_logtype_init, RTE_LOG_DEBUG);
        i40e_logtype_driver = rte_log_register("pmd.net.i40e.driver");
        if (i40e_logtype_driver >= 0)
-               rte_log_set_level(i40e_logtype_driver, RTE_LOG_NOTICE);
+               rte_log_set_level(i40e_logtype_driver, RTE_LOG_DEBUG);
 #ifdef RTE_LIBRTE_I40E_DEBUG_RX
        i40e_logtype_rx = rte_log_register("pmd.net.i40e.rx");

复现过程记录

搭建了个本地环境，使用 l2fwd 与 vpp 复现问题，一直复现不出来。协调测试仪，将 x710 连接到测试仪上的口后，vpp 能够复现出来， 表明问题与测试仪强相关。

vpp 运行 log

出错位置的 log 信息：

Alloc function will be used on port=1, queue=1.
i40e_set_tx_function(): Vector tx finally be used.
i40e_pf_config_rss(): Max of contiguous 2 PF queues are configured
i40e_set_rx_function(): Vector Rx path will be used on port=1.
i40e_dev_rx_queue_start():  >>
i40e_dev_rx_queue_start():  >>
i40e_dev_tx_queue_start():  >>
i40e_dev_tx_queue_start():  >>
i40e_phy_conf_link(): Failed to get the current PHY config: -7

dpdk 驱动中出问题的地方

i40e_apply_link_speed 调用 i40e_phy_conf_link 的时候获取硬件信息失败。i40e_phy_conf_link 关键代码：

/* To get the current phy config. */
	status =i40e_aq_get_phy_capabilities(hw, false, false,&phy_ab,NULL);if(status){PMD_DRV_LOG(ERR,"Failed to get the current PHY config: %d\n",
				status);return ret;}

aq_get_phy_capabilities 通过 i40e 网卡的硬件 admin queue 来获取信息，-7 代表 I40E_ERR_UNKNOWN_PHY ，表明 hw->aq.asq_last_status 状态为 I40E_AQ_RC_EIO ， I/O 错误。

这些信息表明问题指向 网卡硬件 。

l2fwd 程序测试

正常 log 信息：

i40e_dev_rx_queue_start():  >>
i40e_dev_tx_queue_start():  >>
i40e_phy_conf_link():   Current: abilities 0, link_speed c
i40e_phy_conf_link():   Config:  abilities 38, link_speed 7e

dpdk 中相关的 patch

在 dpdk git log 中搜索找到如下提交信息:

commit 935bceb9ba0de8a7a276d5b3dd41e0168a273f26
Author: David Hunt [david.hunt@intel.com](mailto:david.hunt@intel.com)
Date:   Mon Jul 24 09:48:44 2017 +0100
net/i40e: fix sync phy type by adding retry
Some phy's take longer than others to come up. Add a retry to give
more phy's a chance to come up before returning an error.
Fixes: 2209c3e2c275 ("net/i40e: avoid PCI probing failure when using bogus SFP")
Signed-off-by: David Hunt <david.hunt@intel.com
Acked-by: Jingjing Wu <jingjing.wu@intel.com>

补丁代码

参考上面的 git commit，在我们出错的逻辑中添加重试的逻辑，相关 patch 如下：

Index: i40e_ethdev.c
===================================================================--- i40e_ethdev.c(revision xxxxx)+++ i40e_ethdev.c(working copy)
@@ -2159,6+2159,7 @@
        enumi40e_aq_phy_type cnt;uint8_t avail_speed;uint32_t phy_type_mask =0;+int retries =0;constuint8_t mask = I40E_AQ_PHY_FLAG_PAUSE_TX |
                        I40E_AQ_PHY_FLAG_PAUSE_RX |
@@ -2169,20+2170,35 @@
        /* To get phy capabilities of available speeds. */
        status =i40e_aq_get_phy_capabilities(hw, false, true,&phy_ab,NULL);-if(status){+while(status){PMD_DRV_LOG(ERR,"Failed to get PHY capabilities: %d\n",
                                status);-return ret;+               retries++;+rte_delay_us(100000);+if(retries <10)+                       status =i40e_aq_get_phy_capabilities(hw, false, true,&phy_ab,+NULL);+else+return ret;}
        avail_speed = phy_ab.link_speed;/* To get the current phy config. */
        status =i40e_aq_get_phy_capabilities(hw, false, false,&phy_ab,NULL);-if(status){+       retries =0;++while(status){PMD_DRV_LOG(ERR,"Failed to get the current PHY config: %d\n",
                                status);-return ret;+               retries++;+rte_delay_us(100000);++if(retries <10)+                       status =i40e_aq_get_phy_capabilities(hw, false, false,&phy_ab,+NULL);+else+return ret;}

测试记录

重新编译 dpdk 与 vpp 后测试十次，没有出现问题，验证通过。