[dpdk-dev] [PATCH v2 1/2] doc: add user guide for VMDq

[Junyu Jiang <junyux.jiang@intel.com>]

currently, there is no documentation for vmdq example,
this path added the user guide for vmdq.

Signed-off-by: Junyu Jiang <junyux.jiang@intel.com>
---
 MAINTAINERS                                  |   1 +
 doc/guides/sample_app_ug/index.rst           |   1 +
 doc/guides/sample_app_ug/vmdq_forwarding.rst | 208 +++++++++++++++++++
 3 files changed, 210 insertions(+)
 create mode 100644 doc/guides/sample_app_ug/vmdq_forwarding.rst

diff --git a/MAINTAINERS b/MAINTAINERS
index c3785554f..1802356b0 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -1599,5 +1599,6 @@ M: Xiaoyun Li <xiaoyun.li@intel.com>
 F: examples/tep_termination/
 
 F: examples/vmdq/
+F: doc/guides/sample_app_ug/vmdq_forwarding.rst
 F: examples/vmdq_dcb/
 F: doc/guides/sample_app_ug/vmdq_dcb_forwarding.rst
diff --git a/doc/guides/sample_app_ug/index.rst b/doc/guides/sample_app_ug/index.rst
index ac3445147..4b16dd161 100644
--- a/doc/guides/sample_app_ug/index.rst
+++ b/doc/guides/sample_app_ug/index.rst
@@ -40,6 +40,7 @@ Sample Applications User Guides
     timer
     packet_ordering
     vmdq_dcb_forwarding
+    vmdq_forwarding
     vhost
     vhost_blk
     vhost_crypto
diff --git a/doc/guides/sample_app_ug/vmdq_forwarding.rst b/doc/guides/sample_app_ug/vmdq_forwarding.rst
new file mode 100644
index 000000000..df23043d6
--- /dev/null
+++ b/doc/guides/sample_app_ug/vmdq_forwarding.rst
@@ -0,0 +1,208 @@
+..  SPDX-License-Identifier: BSD-3-Clause
+    Copyright(c) 2020 Intel Corporation.
+
+VMDQ Forwarding Sample Application
+==========================================
+
+The VMDQ Forwarding sample application is a simple example of packet processing using the DPDK.
+The application performs L2 forwarding using VMDQ to divide the incoming traffic into queues.
+The traffic splitting is performed in hardware by the VMDQ feature of the Intel® 82599 and X710/XL710 Ethernet Controllers.
+
+Overview
+--------
+
+This sample application can be used as a starting point for developing a new application that is based on the DPDK and
+uses VMDQ for traffic partitioning.
+
+VMDQ filters split the incoming packets up into different "pools" - each with its own set of RX queues - based upon
+the MAC address and VLAN ID within the VLAN tag of the packet.
+
+All traffic is read from a single incoming port and output on another port, without any processing being performed.
+With Intel® 82599 NIC, for example, the traffic is split into 128 queues on input, where each thread of the application reads from
+multiple queues. When run with 8 threads, that is, with the -c FF option, each thread receives and forwards packets from 16 queues.
+
+As supplied, the sample application configures the VMDQ feature to have 32 pools with 4 queues each.
+The Intel® 82599 10 Gigabit Ethernet Controller NIC also supports the splitting of traffic into 16 pools of 2 queues.
+While the Intel® X710 or XL710 Ethernet Controller NICs support many configurations of VMDQ pools of 4 or 8 queues each.
+And queues numbers for each VMDQ pool can be changed by setting CONFIG_RTE_LIBRTE_I40E_QUEUE_NUM_PER_VM
+in config/common_* file.
+The nb-pools parameter can be passed on the command line, after the EAL parameters:
+
+.. code-block:: console
+
+    ./build/vmdq_app [EAL options] -- -p PORTMASK --nb-pools NP
+
+where, NP can be 8, 16 or 32.
+
+In Linux* user space, the application can display statistics with the number of packets received on each queue.
+To have the application display the statistics, send a SIGHUP signal to the running application process.
+
+The VMDQ Forwarding sample application is in many ways simpler than the L2 Forwarding application
+(see :doc:`l2_forward_real_virtual`)
+as it performs unidirectional L2 forwarding of packets from one port to a second port.
+No command-line options are taken by this application apart from the standard EAL command-line options.
+
+Compiling the Application
+-------------------------
+
+To compile the sample application see :doc:`compiling`.
+
+The application is located in the ``vmdq`` sub-directory.
+
+Running the Application
+-----------------------
+
+To run the example in a linux environment:
+
+.. code-block:: console
+
+    user@target:~$ ./build/vmdq_app -l 0-3 -n 4 -- -p 0x3 --nb-pools 16
+
+Refer to the *DPDK Getting Started Guide* for general information on running applications and
+the Environment Abstraction Layer (EAL) options.
+
+Explanation
+-----------
+
+The following sections provide some explanation of the code.
+
+Initialization
+~~~~~~~~~~~~~~
+
+The EAL, driver and PCI configuration is performed largely as in the L2 Forwarding sample application,
+as is the creation of the mbuf pool.
+See :doc:`l2_forward_real_virtual`.
+Where this example application differs is in the configuration of the NIC port for RX.
+
+The VMDQ hardware feature is configured at port initialization time by setting the appropriate values in the
+rte_eth_conf structure passed to the rte_eth_dev_configure() API.
+Initially in the application,
+a default structure is provided for VMDQ configuration to be filled in later by the application.
+
+.. code-block:: c
+
+    /* empty vmdq configuration structure. Filled in programatically */
+    static const struct rte_eth_conf vmdq_conf_default = {
+        .rxmode = {
+            .mq_mode        = ETH_MQ_RX_VMDQ_ONLY,
+            .split_hdr_size = 0,
+        },
+
+        .txmode = {
+            .mq_mode = ETH_MQ_TX_NONE,
+        },
+        .rx_adv_conf = {
+            /*
+            * should be overridden separately in code with
+            * appropriate values
+            */
+            .vmdq_rx_conf = {
+                .nb_queue_pools = ETH_8_POOLS,
+                .enable_default_pool = 0,
+                .default_pool = 0,
+                .nb_pool_maps = 0,
+                .pool_map = {{0, 0},},
+            },
+        },
+    };
+
+The get_eth_conf() function fills in an rte_eth_conf structure with the appropriate values,
+based on the global vlan_tags array.
+For the VLAN IDs, each one can be allocated to possibly multiple pools of queues.
+For destination MAC, each VMDQ pool will be assigned with a MAC address. In this sample, each VMDQ pool
+is assigned to the MAC like 52:54:00:12:<port_id>:<pool_id>, that is,
+the MAC of VMDQ pool 2 on port 1 is 52:54:00:12:01:02.
+
+.. code-block:: c
+
+    const uint16_t vlan_tags[] = {
+        0,  1,  2,  3,  4,  5,  6,  7,
+        8,  9, 10, 11,	12, 13, 14, 15,
+        16, 17, 18, 19, 20, 21, 22, 23,
+        24, 25, 26, 27, 28, 29, 30, 31,
+        32, 33, 34, 35, 36, 37, 38, 39,
+        40, 41, 42, 43, 44, 45, 46, 47,
+        48, 49, 50, 51, 52, 53, 54, 55,
+        56, 57, 58, 59, 60, 61, 62, 63,
+    };
+
+    /* pool mac addr template, pool mac addr is like: 52 54 00 12 port# pool# */
+    static struct rte_ether_addr pool_addr_template = {
+        .addr_bytes = {0x52, 0x54, 0x00, 0x12, 0x00, 0x00}
+    };
+
+    /*
+     * Builds up the correct configuration for vmdq based on the vlan tags array
+     * given above, and determine the queue number and pool map number according to
+     * valid pool number
+     */
+    static inline int
+    get_eth_conf(struct rte_eth_conf *eth_conf, uint32_t num_pools)
+    {
+        struct rte_eth_vmdq_rx_conf conf;
+        unsigned i;
+
+        conf.nb_queue_pools = (enum rte_eth_nb_pools)num_pools;
+        conf.nb_pool_maps = num_pools;
+        conf.enable_default_pool = 0;
+        conf.default_pool = 0; /* set explicit value, even if not used */
+
+        for (i = 0; i < conf.nb_pool_maps; i++) {
+            conf.pool_map[i].vlan_id = vlan_tags[i];
+            conf.pool_map[i].pools = (1UL << (i % num_pools));
+        }
+
+        (void)(rte_memcpy(eth_conf, &vmdq_conf_default, sizeof(*eth_conf)));
+        (void)(rte_memcpy(&eth_conf->rx_adv_conf.vmdq_rx_conf, &conf,
+            sizeof(eth_conf->rx_adv_conf.vmdq_rx_conf)));
+        return 0;
+    }
+
+    ......
+
+    /*
+     * Set mac for each pool.
+     * There is no default mac for the pools in i40.
+     * Removes this after i40e fixes this issue.
+     */
+    for (q = 0; q < num_pools; q++) {
+    	struct rte_ether_addr mac;
+    	mac = pool_addr_template;
+    	mac.addr_bytes[4] = port;
+    	mac.addr_bytes[5] = q;
+    	printf("Port %u vmdq pool %u set mac %02x:%02x:%02x:%02x:%02x:%02x\n",
+    		port, q,
+    		mac.addr_bytes[0], mac.addr_bytes[1],
+    		mac.addr_bytes[2], mac.addr_bytes[3],
+    		mac.addr_bytes[4], mac.addr_bytes[5]);
+    	retval = rte_eth_dev_mac_addr_add(port, &mac,
+    			q + vmdq_pool_base);
+    	if (retval) {
+    		printf("mac addr add failed at pool %d\n", q);
+    		return retval;
+    	}
+    }
+
+Once the network port has been initialized using the correct VMDQ values,
+the initialization of the port's RX and TX hardware rings is performed similarly to that
+in the L2 Forwarding sample application.
+See :doc:`l2_forward_real_virtual` for more information.
+
+Statistics Display
+~~~~~~~~~~~~~~~~~~
+
+When run in a linux environment,
+the VMDQ Forwarding sample application can display statistics showing the number of packets read from each RX queue.
+This is provided by way of a signal handler for the SIGHUP signal,
+which simply prints to standard output the packet counts in grid form.
+Each row of the output is a single pool with the columns being the queue number within that pool.
+
+To generate the statistics output, use the following command:
+
+.. code-block:: console
+
+    user@host$ sudo killall -HUP vmdq_app
+
+Please note that the statistics output will appear on the terminal where the vmdq_app is running,
+rather than the terminal from which the HUP signal was sent.
+
-- 
2.17.1