1.. BSD LICENSE 2 Copyright(c) 2010-2014 Intel Corporation. All rights reserved. 3 All rights reserved. 4 5 Redistribution and use in source and binary forms, with or without 6 modification, are permitted provided that the following conditions 7 are met: 8 9 * Redistributions of source code must retain the above copyright 10 notice, this list of conditions and the following disclaimer. 11 * Redistributions in binary form must reproduce the above copyright 12 notice, this list of conditions and the following disclaimer in 13 the documentation and/or other materials provided with the 14 distribution. 15 * Neither the name of Intel Corporation nor the names of its 16 contributors may be used to endorse or promote products derived 17 from this software without specific prior written permission. 18 19 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 20 "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 21 LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 22 A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 23 OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 24 SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 25 LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 26 DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 27 THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 28 (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 29 OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 30 31VMDQ and DCB Forwarding Sample Application 32========================================== 33 34The VMDQ and DCB Forwarding sample application is a simple example of packet processing using the DPDK. 35The application performs L2 forwarding using VMDQ and DCB to divide the incoming traffic into 128 queues. 36The traffic splitting is performed in hardware by the VMDQ and DCB features of the Intel® 82599 10 Gigabit Ethernet Controller. 37 38Overview 39-------- 40 41This sample application can be used as a starting point for developing a new application that is based on the DPDK and 42uses VMDQ and DCB for traffic partitioning. 43 44The VMDQ and DCB filters work on VLAN traffic to divide the traffic into 128 input queues on the basis of the VLAN ID field and 45VLAN user priority field. 46VMDQ filters split the traffic into 16 or 32 groups based on the VLAN ID. 47Then, DCB places each packet into one of either 4 or 8 queues within that group, based upon the VLAN user priority field. 48 49In either case, 16 groups of 8 queues, or 32 groups of 4 queues, the traffic can be split into 128 hardware queues on the NIC, 50each of which can be polled individually by a DPDK application. 51 52All traffic is read from a single incoming port (port 0) and output on port 1, without any processing being performed. 53The traffic is split into 128 queues on input, where each thread of the application reads from multiple queues. 54For example, when run with 8 threads, that is, with the -c FF option, each thread receives and forwards packets from 16 queues. 55 56As supplied, the sample application configures the VMDQ feature to have 16 pools with 8 queues each as indicated in Figure 15. 57The Intel® 82599 10 Gigabit Ethernet Controller NIC also supports the splitting of traffic into 32 pools of 4 queues each and 58this can be used by changing the NUM_POOLS parameter in the supplied code. 59The NUM_POOLS parameter can be passed on the command line, after the EAL parameters: 60 61.. code-block:: console 62 63 ./build/vmdq_dcb [EAL options] -- -p PORTMASK --nb-pools NP 64 65where, NP can be 16 or 32. 66 67.. _figure_15: 68 69**Figure 15. Packet Flow Through the VMDQ and DCB Sample Application** 70 71.. image18_png has been replaced 72 73|vmdq_dcb_example| 74 75In Linux* user space, the application can display statistics with the number of packets received on each queue. 76To have the application display the statistics, send a SIGHUP signal to the running application process, as follows: 77 78where, <pid> is the process id of the application process. 79 80The VMDQ and DCB Forwarding sample application is in many ways simpler than the L2 Forwarding application 81(see Chapter 9 , "L2 Forwarding Sample Application (in Real and Virtualized Environments)") 82as it performs unidirectional L2 forwarding of packets from one port to a second port. 83No command-line options are taken by this application apart from the standard EAL command-line options. 84 85.. note:: 86 87 Since VMD queues are being used for VMM, this application works correctly 88 when VTd is disabled in the BIOS or Linux* kernel (intel_iommu=off). 89 90Compiling the Application 91------------------------- 92 93#. Go to the examples directory: 94 95 .. code-block:: console 96 97 export RTE_SDK=/path/to/rte_sdk cd ${RTE_SDK}/examples/vmdq_dcb 98 99#. Set the target (a default target is used if not specified). For example: 100 101 .. code-block:: console 102 103 export RTE_TARGET=x86_64-native-linuxapp-gcc 104 105 See the *DPDK Getting Started Guide* for possible RTE_TARGET values. 106 107#. Build the application: 108 109 .. code-block:: console 110 111 make 112 113Running the Application 114----------------------- 115 116To run the example in a linuxapp environment: 117 118.. code-block:: console 119 120 user@target:~$ ./build/vmdq_dcb -c f -n 4 -- -p 0x3 --nb-pools 16 121 122Refer to the *DPDK Getting Started Guide* for general information on running applications and 123the Environment Abstraction Layer (EAL) options. 124 125Explanation 126----------- 127 128The following sections provide some explanation of the code. 129 130Initialization 131~~~~~~~~~~~~~~ 132 133The EAL, driver and PCI configuration is performed largely as in the L2 Forwarding sample application, 134as is the creation of the mbuf pool. 135See Chapter 9, "L2 Forwarding Sample Application (in Real and Virtualized Environments)". 136Where this example application differs is in the configuration of the NIC port for RX. 137 138The VMDQ and DCB hardware feature is configured at port initialization time by setting the appropriate values in the 139rte_eth_conf structure passed to the rte_eth_dev_configure() API. 140Initially in the application, 141a default structure is provided for VMDQ and DCB configuration to be filled in later by the application. 142 143.. code-block:: c 144 145 /* empty vmdq+dcb configuration structure. Filled in programmatically */ 146 147 static const struct rte_eth_conf vmdq_dcb_conf_default = { 148 .rxmode = { 149 .mq_mode = ETH_VMDQ_DCB, 150 .split_hdr_size = 0, 151 .header_split = 0, /**< Header Split disabled */ 152 .hw_ip_checksum = 0, /**< IP checksum offload disabled */ 153 .hw_vlan_filter = 0, /**< VLAN filtering disabled */ 154 .jumbo_frame = 0, /**< Jumbo Frame Support disabled */ 155 }, 156 157 .txmode = { 158 .mq_mode = ETH_DCB_NONE, 159 }, 160 161 .rx_adv_conf = { 162 /* 163 * should be overridden separately in code with 164 * appropriate values 165 */ 166 167 .vmdq_dcb_conf = { 168 .nb_queue_pools = ETH_16_POOLS, 169 .enable_default_pool = 0, 170 .default_pool = 0, 171 .nb_pool_maps = 0, 172 .pool_map = {{0, 0},}, 173 .dcb_queue = {0}, 174 }, 175 }, 176 }; 177 178The get_eth_conf() function fills in an rte_eth_conf structure with the appropriate values, 179based on the global vlan_tags array, 180and dividing up the possible user priority values equally among the individual queues 181(also referred to as traffic classes) within each pool, that is, 182if the number of pools is 32, then the user priority fields are allocated two to a queue. 183If 16 pools are used, then each of the 8 user priority fields is allocated to its own queue within the pool. 184For the VLAN IDs, each one can be allocated to possibly multiple pools of queues, 185so the pools parameter in the rte_eth_vmdq_dcb_conf structure is specified as a bitmask value. 186 187.. code-block:: c 188 189 const uint16_t vlan_tags[] = { 190 0, 1, 2, 3, 4, 5, 6, 7, 191 8, 9, 10, 11, 12, 13, 14, 15, 192 16, 17, 18, 19, 20, 21, 22, 23, 193 24, 25, 26, 27, 28, 29, 30, 31 194 }; 195 196 197 /* Builds up the correct configuration for vmdq+dcb based on the vlan tags array 198 * given above, and the number of traffic classes available for use. */ 199 200 static inline int 201 get_eth_conf(struct rte_eth_conf *eth_conf, enum rte_eth_nb_pools num_pools) 202 { 203 struct rte_eth_vmdq_dcb_conf conf; 204 unsigned i; 205 206 if (num_pools != ETH_16_POOLS && num_pools != ETH_32_POOLS ) return -1; 207 208 conf.nb_queue_pools = num_pools; 209 conf.enable_default_pool = 0; 210 conf.default_pool = 0; /* set explicit value, even if not used */ 211 conf.nb_pool_maps = sizeof( vlan_tags )/sizeof( vlan_tags[ 0 ]); 212 213 for (i = 0; i < conf.nb_pool_maps; i++){ 214 conf.pool_map[i].vlan_id = vlan_tags[ i ]; 215 conf.pool_map[i].pools = 1 << (i % num_pools); 216 } 217 218 for (i = 0; i < ETH_DCB_NUM_USER_PRIORITIES; i++){ 219 conf.dcb_queue[i] = (uint8_t)(i % (NUM_QUEUES/num_pools)); 220 } 221 222 (void) rte_memcpy(eth_conf, &vmdq_dcb_conf_default, sizeof(\*eth_conf)); 223 (void) rte_memcpy(ð_conf->rx_adv_conf.vmdq_dcb_conf, &conf, sizeof(eth_conf->rx_adv_conf.vmdq_dcb_conf)); 224 225 return 0; 226 } 227 228Once the network port has been initialized using the correct VMDQ and DCB values, 229the initialization of the port's RX and TX hardware rings is performed similarly to that 230in the L2 Forwarding sample application. 231See Chapter 9, "L2 Forwarding Sample Application (in Real and Virtualized Environments)" for more information. 232 233Statistics Display 234~~~~~~~~~~~~~~~~~~ 235 236When run in a linuxapp environment, 237the VMDQ and DCB Forwarding sample application can display statistics showing the number of packets read from each RX queue. 238This is provided by way of a signal handler for the SIGHUP signal, 239which simply prints to standard output the packet counts in grid form. 240Each row of the output is a single pool with the columns being the queue number within that pool. 241 242To generate the statistics output, use the following command: 243 244.. code-block:: console 245 246 user@host$ sudo killall -HUP vmdq_dcb_app 247 248Please note that the statistics output will appear on the terminal where the vmdq_dcb_app is running, 249rather than the terminal from which the HUP signal was sent. 250 251.. |vmdq_dcb_example| image:: img/vmdq_dcb_example.* 252