[dpdk-dev,v5,4/4] examples/ethtool: add control interface support to the application

  Control interface APIs added into the sample application.

To have the support corresponding kernel module (KCP) needs to be inserted.
If kernel module is not there, application will run as it is without
kernel control path support.

When KCP module inserted, running application creates a virtual Linux
network interface (dpdk$) per DPDK port. This interface can be used by
traditional Linux tools.

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
Acked-by: Remy Horton <remy.horton@intel.com>
---

v4, v5:
* No update

v3:
* Use blocking mode control interface processing, instead of poll mode

v2:
* No update on sample app
---
 doc/guides/sample_app_ug/ethtool.rst | 41 ++++++++++++++++++++++++++++++++++++
 examples/ethtool/main.c              | 31 +++++++++++++++++++++++++--
 2 files changed, 70 insertions(+), 2 deletions(-)
  

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Ferruh Yigit
> Sent: Wednesday, March 09, 2016 11:41 AM
> To: dev@dpdk.org
> Subject: [dpdk-dev] [PATCH v5 4/4] examples/ethtool: add control interface support to the application
> 
> Control interface APIs added into the sample application.
> 
> To have the support corresponding kernel module (KCP) needs to be inserted.
> If kernel module is not there, application will run as it is without
> kernel control path support.
> 
> When KCP module inserted, running application creates a virtual Linux
> network interface (dpdk$) per DPDK port. This interface can be used by
> traditional Linux tools.
> 
> Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>
> Acked-by: Remy Horton <remy.horton@intel.com>
> ---
> 
> v4, v5:
> * No update
> 
> v3:
> * Use blocking mode control interface processing, instead of poll mode
> 
> v2:
> * No update on sample app
> ---
>  doc/guides/sample_app_ug/ethtool.rst | 41 ++++++++++++++++++++++++++++++++++++
>  examples/ethtool/main.c              | 31 +++++++++++++++++++++++++--
>  2 files changed, 70 insertions(+), 2 deletions(-)
> 
> diff --git a/doc/guides/sample_app_ug/ethtool.rst b/doc/guides/sample_app_ug/ethtool.rst
> index 65240ae..af591c2 100644
> --- a/doc/guides/sample_app_ug/ethtool.rst
> +++ b/doc/guides/sample_app_ug/ethtool.rst
> @@ -130,3 +130,44 @@ interface that accepts commands as described in `using the
>  application`_. Individual call-back functions handle the detail
>  associated with each command, which make use of librte_ethtool
>  library.
> +
> +Control Interface
> +~~~~~~~~~~~~~~~~~
> +
> +If Kernel Control Path (KCP) kernel module (rte_kcp.ko) inserted,
> +virtual interfaces created for each DPDK port for control purposes.
> +
> +Created interfaces are named as dpdk#, like:
> +
> +.. code-block:: console
> +
> +        # ifconfig dpdk0; ifconfig dpdk1
> +        dpdk0: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
> +                ether 90:e2:ba:0e:49:b9  txqueuelen 1000  (Ethernet)
> +                RX packets 0  bytes 0 (0.0 B)
> +                RX errors 0  dropped 0  overruns 0  frame 0
> +                TX packets 0  bytes 0 (0.0 B)
> +                TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
> +
> +        dpdk1: flags=4099<UP,BROADCAST,MULTICAST>  mtu 1500
> +                ether 00:1b:21:76:fa:21  txqueuelen 1000  (Ethernet)
> +                RX packets 0  bytes 0 (0.0 B)
> +                RX errors 0  dropped 0  overruns 0  frame 0
> +                TX packets 0  bytes 0 (0.0 B)
> +                TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0
> +
> +Regular Linux commands can be issued on interfaces:
> +
> +.. code-block:: console
> +
> +        # ethtool -i dpdk0
> +        driver: rte_ixgbe_pmd
> +        version: RTE 2.3.0-rc0
> +        firmware-version:
> +        expansion-rom-version:
> +        bus-info: 0000:08:00.1
> +        supports-statistics: yes
> +        supports-test: no
> +        supports-eeprom-access: yes
> +        supports-register-dump: yes
> +        supports-priv-flags: no
> diff --git a/examples/ethtool/main.c b/examples/ethtool/main.c
> index 2c655d8..72fbe4c 100644
> --- a/examples/ethtool/main.c
> +++ b/examples/ethtool/main.c
> @@ -1,7 +1,7 @@
>  /*-
>   *   BSD LICENSE
>   *
> - *   Copyright(c) 2015 Intel Corporation. All rights reserved.
> + *   Copyright(c) 2015-2016 Intel Corporation. All rights reserved.
>   *   All rights reserved.
>   *
>   *   Redistribution and use in source and binary forms, with or without
> @@ -44,6 +44,7 @@
>  #include <rte_memory.h>
>  #include <rte_mempool.h>
>  #include <rte_mbuf.h>
> +#include <rte_ctrl_if.h>
> 
>  #include "ethapp.h"
> 
> @@ -54,7 +55,6 @@
>  #define PKTPOOL_EXTRA_SIZE 512
>  #define PKTPOOL_CACHE 32
> 
> -
>  struct txq_port {
>  	uint16_t cnt_unsent;
>  	struct rte_mbuf *buf_frames[MAX_BURST_LENGTH];
> @@ -259,11 +259,32 @@ static int slave_main(__attribute__((unused)) void *ptr_data)
>  	return 0;
>  }
> 
> +static void *
> +control_function(__attribute__((unused)) void *arg)
> +{
> +	int port_id;
> +
> +	while (1) {
> +		/* blocking call with 1 sec timeout */
> +		port_id = rte_eth_control_interface_msg_exist(1);
> +		if (port_id < 0)
> +			continue;
> +
> +		lock_port(port_id);
> +		rte_eth_control_interface_msg_process(
> +			RTE_ETHTOOL_CTRL_IF_PROCESS_MSG);
> +		unlock_port(port_id);


As I stated in offline code review, I think that just lock/unlock here is not enough.
You either have to  update port_active flag here based on dev->data->dev_started,
or check  dev->data->dev_started directly in your data-path or somehow else
inform IO thread that the port is stopped and RX/TX is not possible over it.
Otherwise sending stop command over your control interface while RX/TX is active
would cause your app to crash. 
Konstantin

> +	}
> +
> +	return 0;
> +}
> +
>  int main(int argc, char **argv)
>  {
>  	int cnt_args_parsed;
>  	uint32_t id_core;
>  	uint32_t cnt_ports;
> +	pthread_t control_thread;
> 
>  	/* Init runtime enviornment */
>  	cnt_args_parsed = rte_eal_init(argc, argv);
> @@ -293,6 +314,9 @@ int main(int argc, char **argv)
>  	id_core = rte_get_next_lcore(id_core, 1, 1);
>  	rte_eal_remote_launch(slave_main, NULL, id_core);
> 
> +	pthread_create(&control_thread, NULL, control_function, NULL);
> +	rte_eth_control_interface_create();
> +
>  	ethapp_main();
> 
>  	app_cfg.exit_now = 1;
> @@ -301,5 +325,8 @@ int main(int argc, char **argv)
>  			return -1;
>  	}
> 
> +	rte_eth_control_interface_destroy();
> +	pthread_cancel(control_thread);
> +
>  	return 0;
>  }
> --
> 2.5.0