--- /dev/null
+.. BSD LICENSE
+ Copyright(c) 2010-2014 Intel Corporation. All rights reserved.
+ All rights reserved.
+
+ Redistribution and use in source and binary forms, with or without
+ modification, are permitted provided that the following conditions
+ are met:
+
+ * Redistributions of source code must retain the above copyright
+ notice, this list of conditions and the following disclaimer.
+ * Redistributions in binary form must reproduce the above copyright
+ notice, this list of conditions and the following disclaimer in
+ the documentation and/or other materials provided with the
+ distribution.
+ * Neither the name of Intel Corporation nor the names of its
+ contributors may be used to endorse or promote products derived
+ from this software without specific prior written permission.
+
+ THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+Kernel NIC Interface Sample Application
+=======================================
+
+The Kernel NIC Interface (KNI) is a DPDK control plane solution that
+allows userspace applications to exchange packets with the kernel networking stack.
+To accomplish this, DPDK userspace applications use an IOCTL call
+to request the creation of a KNI virtual device in the Linux* kernel.
+The IOCTL call provides interface information and the DPDK's physical address space,
+which is re-mapped into the kernel address space by the KNI kernel loadable module
+that saves the information to a virtual device context.
+The DPDK creates FIFO queues for packet ingress and egress
+to the kernel module for each device allocated.
+
+The KNI kernel loadable module is a standard net driver,
+which upon receiving the IOCTL call access the DPDK's FIFO queue to
+receive/transmit packets from/to the DPDK userspace application.
+The FIFO queues contain pointers to data packets in the DPDK. This:
+
+* Provides a faster mechanism to interface with the kernel net stack and eliminates system calls
+
+* Facilitates the DPDK using standard Linux* userspace net tools (tcpdump, ftp, and so on)
+
+* Eliminate the copy_to_user and copy_from_user operations on packets.
+
+The Kernel NIC Interface sample application is a simple example that demonstrates the use
+of the DPDK to create a path for packets to go through the Linux* kernel.
+This is done by creating one or more kernel net devices for each of the DPDK ports.
+The application allows the use of standard Linux tools (ethtool, ifconfig, tcpdump) with the DPDK ports and
+also the exchange of packets between the DPDK application and the Linux* kernel.
+
+Overview
+--------
+
+The Kernel NIC Interface sample application uses two threads in user space for each physical NIC port being used,
+and allocates one or more KNI device for each physical NIC port with kernel module's support.
+For a physical NIC port, one thread reads from the port and writes to KNI devices,
+and another thread reads from KNI devices and writes the data unmodified to the physical NIC port.
+It is recommended to configure one KNI device for each physical NIC port.
+If configured with more than one KNI devices for a physical NIC port,
+it is just for performance testing, or it can work together with VMDq support in future.
+
+The packet flow through the Kernel NIC Interface application is as shown in the following figure.
+
+.. _figure_kernel_nic:
+
+.. figure:: img/kernel_nic.*
+
+ Kernel NIC Application Packet Flow
+
+
+Compiling the Application
+-------------------------
+
+Compile the application as follows:
+
+#. Go to the example directory:
+
+ .. code-block:: console
+
+ export RTE_SDK=/path/to/rte_sdk
+ cd ${RTE_SDK}/examples/kni
+
+#. Set the target (a default target is used if not specified)
+
+ .. note::
+
+ This application is intended as a linuxapp only.
+
+ .. code-block:: console
+
+ export RTE_TARGET=x86_64-native-linuxapp-gcc
+
+#. Build the application:
+
+ .. code-block:: console
+
+ make
+
+Loading the Kernel Module
+-------------------------
+
+Loading the KNI kernel module without any parameter is the typical way a DPDK application
+gets packets into and out of the kernel net stack.
+This way, only one kernel thread is created for all KNI devices for packet receiving in kernel side:
+
+.. code-block:: console
+
+ #insmod rte_kni.ko
+
+Pinning the kernel thread to a specific core can be done using a taskset command such as following:
+
+.. code-block:: console
+
+ #taskset -p 100000 `pgrep --fl kni_thread | awk '{print $1}'`
+
+This command line tries to pin the specific kni_thread on the 20th lcore (lcore numbering starts at 0),
+which means it needs to check if that lcore is available on the board.
+This command must be sent after the application has been launched, as insmod does not start the kni thread.
+
+For optimum performance,
+the lcore in the mask must be selected to be on the same socket as the lcores used in the KNI application.
+
+To provide flexibility of performance, the kernel module of the KNI,
+located in the kmod sub-directory of the DPDK target directory,
+can be loaded with parameter of kthread_mode as follows:
+
+* #insmod rte_kni.ko kthread_mode=single
+
+ This mode will create only one kernel thread for all KNI devices for packet receiving in kernel side.
+ By default, it is in this single kernel thread mode.
+ It can set core affinity for this kernel thread by using Linux command taskset.
+
+* #insmod rte_kni.ko kthread_mode =multiple
+
+ This mode will create a kernel thread for each KNI device for packet receiving in kernel side.
+ The core affinity of each kernel thread is set when creating the KNI device.
+ The lcore ID for each kernel thread is provided in the command line of launching the application.
+ Multiple kernel thread mode can provide scalable higher performance.
+
+To measure the throughput in a loopback mode, the kernel module of the KNI,
+located in the kmod sub-directory of the DPDK target directory,
+can be loaded with parameters as follows:
+
+* #insmod rte_kni.ko lo_mode=lo_mode_fifo
+
+ This loopback mode will involve ring enqueue/dequeue operations in kernel space.
+
+* #insmod rte_kni.ko lo_mode=lo_mode_fifo_skb
+
+ This loopback mode will involve ring enqueue/dequeue operations and sk buffer copies in kernel space.
+
+Running the Application
+-----------------------
+
+The application requires a number of command line options:
+
+.. code-block:: console
+
+ kni [EAL options] -- -P -p PORTMASK --config="(port,lcore_rx,lcore_tx[,lcore_kthread,...])[,port,lcore_rx,lcore_tx[,lcore_kthread,...]]"
+
+Where:
+
+* -P: Set all ports to promiscuous mode so that packets are accepted regardless of the packet's Ethernet MAC destination address.
+ Without this option, only packets with the Ethernet MAC destination address set to the Ethernet address of the port are accepted.
+
+* -p PORTMASK: Hexadecimal bitmask of ports to configure.
+
+* --config="(port,lcore_rx, lcore_tx[,lcore_kthread, ...]) [, port,lcore_rx, lcore_tx[,lcore_kthread, ...]]":
+ Determines which lcores of RX, TX, kernel thread are mapped to which ports.
+
+Refer to *DPDK Getting Started Guide* for general information on running applications and the Environment Abstraction Layer (EAL) options.
+
+The -c coremask parameter of the EAL options should include the lcores indicated by the lcore_rx and lcore_tx,
+but does not need to include lcores indicated by lcore_kthread as they are used to pin the kernel thread on.
+The -p PORTMASK parameter should include the ports indicated by the port in --config, neither more nor less.
+
+The lcore_kthread in --config can be configured none, one or more lcore IDs.
+In multiple kernel thread mode, if configured none, a KNI device will be allocated for each port,
+while no specific lcore affinity will be set for its kernel thread.
+If configured one or more lcore IDs, one or more KNI devices will be allocated for each port,
+while specific lcore affinity will be set for its kernel thread.
+In single kernel thread mode, if configured none, a KNI device will be allocated for each port.
+If configured one or more lcore IDs,
+one or more KNI devices will be allocated for each port while
+no lcore affinity will be set as there is only one kernel thread for all KNI devices.
+
+For example, to run the application with two ports served by six lcores, one lcore of RX, one lcore of TX,
+and one lcore of kernel thread for each port:
+
+.. code-block:: console
+
+ ./build/kni -c 0xf0 -n 4 -- -P -p 0x3 -config="(0,4,6,8),(1,5,7,9)"
+
+KNI Operations
+--------------
+
+Once the KNI application is started, one can use different Linux* commands to manage the net interfaces.
+If more than one KNI devices configured for a physical port,
+only the first KNI device will be paired to the physical device.
+Operations on other KNI devices will not affect the physical port handled in user space application.
+
+Assigning an IP address:
+
+.. code-block:: console
+
+ #ifconfig vEth0_0 192.168.0.1
+
+Displaying the NIC registers:
+
+.. code-block:: console
+
+ #ethtool -d vEth0_0
+
+Dumping the network traffic:
+
+.. code-block:: console
+
+ #tcpdump -i vEth0_0
+
+When the DPDK userspace application is closed, all the KNI devices are deleted from Linux*.
+
+Explanation
+-----------
+
+The following sections provide some explanation of code.
+
+Initialization
+~~~~~~~~~~~~~~
+
+Setup of mbuf pool, driver and queues is similar to the setup done in the :doc:`l2_forward_real_virtual`..
+In addition, one or more kernel NIC interfaces are allocated for each
+of the configured ports according to the command line parameters.
+
+The code for allocating the kernel NIC interfaces for a specific port is as follows:
+
+.. code-block:: c
+
+ static int
+ kni_alloc(uint8_t port_id)
+ {
+ uint8_t i;
+ struct rte_kni *kni;
+ struct rte_kni_conf conf;
+ struct kni_port_params **params = kni_port_params_array;
+
+ if (port_id >= RTE_MAX_ETHPORTS || !params[port_id])
+ return -1;
+
+ params[port_id]->nb_kni = params[port_id]->nb_lcore_k ? params[port_id]->nb_lcore_k : 1;
+
+ for (i = 0; i < params[port_id]->nb_kni; i++) {
+
+ /* Clear conf at first */
+
+ memset(&conf, 0, sizeof(conf));
+ if (params[port_id]->nb_lcore_k) {
+ snprintf(conf.name, RTE_KNI_NAMESIZE, "vEth%u_%u", port_id, i);
+ conf.core_id = params[port_id]->lcore_k[i];
+ conf.force_bind = 1;
+ } else
+ snprintf(conf.name, RTE_KNI_NAMESIZE, "vEth%u", port_id);
+ conf.group_id = (uint16_t)port_id;
+ conf.mbuf_size = MAX_PACKET_SZ;
+
+ /*
+ * The first KNI device associated to a port
+ * is the master, for multiple kernel thread
+ * environment.
+ */
+
+ if (i == 0) {
+ struct rte_kni_ops ops;
+ struct rte_eth_dev_info dev_info;
+
+ memset(&dev_info, 0, sizeof(dev_info)); rte_eth_dev_info_get(port_id, &dev_info);
+
+ conf.addr = dev_info.pci_dev->addr;
+ conf.id = dev_info.pci_dev->id;
+
+ memset(&ops, 0, sizeof(ops));
+
+ ops.port_id = port_id;
+ ops.change_mtu = kni_change_mtu;
+ ops.config_network_if = kni_config_network_interface;
+
+ kni = rte_kni_alloc(pktmbuf_pool, &conf, &ops);
+ } else
+ kni = rte_kni_alloc(pktmbuf_pool, &conf, NULL);
+
+ if (!kni)
+ rte_exit(EXIT_FAILURE, "Fail to create kni for "
+ "port: %d\n", port_id);
+
+ params[port_id]->kni[i] = kni;
+ }
+ return 0;
+ }
+
+The other step in the initialization process that is unique to this sample application
+is the association of each port with lcores for RX, TX and kernel threads.
+
+* One lcore to read from the port and write to the associated one or more KNI devices
+
+* Another lcore to read from one or more KNI devices and write to the port
+
+* Other lcores for pinning the kernel threads on one by one
+
+This is done by using the`kni_port_params_array[]` array, which is indexed by the port ID.
+The code is as follows:
+
+.. code-block:: console
+
+ static int
+ parse_config(const char *arg)
+ {
+ const char *p, *p0 = arg;
+ char s[256], *end;
+ unsigned size;
+ enum fieldnames {
+ FLD_PORT = 0,
+ FLD_LCORE_RX,
+ FLD_LCORE_TX,
+ _NUM_FLD = KNI_MAX_KTHREAD + 3,
+ };
+ int i, j, nb_token;
+ char *str_fld[_NUM_FLD];
+ unsigned long int_fld[_NUM_FLD];
+ uint8_t port_id, nb_kni_port_params = 0;
+
+ memset(&kni_port_params_array, 0, sizeof(kni_port_params_array));
+
+ while (((p = strchr(p0, '(')) != NULL) && nb_kni_port_params < RTE_MAX_ETHPORTS) {
+ p++;
+ if ((p0 = strchr(p, ')')) == NULL)
+ goto fail;
+
+ size = p0 - p;
+
+ if (size >= sizeof(s)) {
+ printf("Invalid config parameters\n");
+ goto fail;
+ }
+
+ snprintf(s, sizeof(s), "%.*s", size, p);
+ nb_token = rte_strsplit(s, sizeof(s), str_fld, _NUM_FLD, ',');
+
+ if (nb_token <= FLD_LCORE_TX) {
+ printf("Invalid config parameters\n");
+ goto fail;
+ }
+
+ for (i = 0; i < nb_token; i++) {
+ errno = 0;
+ int_fld[i] = strtoul(str_fld[i], &end, 0);
+ if (errno != 0 || end == str_fld[i]) {
+ printf("Invalid config parameters\n");
+ goto fail;
+ }
+ }
+
+ i = 0;
+ port_id = (uint8_t)int_fld[i++];
+
+ if (port_id >= RTE_MAX_ETHPORTS) {
+ printf("Port ID %u could not exceed the maximum %u\n", port_id, RTE_MAX_ETHPORTS);
+ goto fail;
+ }
+
+ if (kni_port_params_array[port_id]) {
+ printf("Port %u has been configured\n", port_id);
+ goto fail;
+ }
+
+ kni_port_params_array[port_id] = (struct kni_port_params*)rte_zmalloc("KNI_port_params", sizeof(struct kni_port_params), RTE_CACHE_LINE_SIZE);
+ kni_port_params_array[port_id]->port_id = port_id;
+ kni_port_params_array[port_id]->lcore_rx = (uint8_t)int_fld[i++];
+ kni_port_params_array[port_id]->lcore_tx = (uint8_t)int_fld[i++];
+
+ if (kni_port_params_array[port_id]->lcore_rx >= RTE_MAX_LCORE || kni_port_params_array[port_id]->lcore_tx >= RTE_MAX_LCORE) {
+ printf("lcore_rx %u or lcore_tx %u ID could not "
+ "exceed the maximum %u\n",
+ kni_port_params_array[port_id]->lcore_rx, kni_port_params_array[port_id]->lcore_tx, RTE_MAX_LCORE);
+ goto fail;
+ }
+
+ for (j = 0; i < nb_token && j < KNI_MAX_KTHREAD; i++, j++)
+ kni_port_params_array[port_id]->lcore_k[j] = (uint8_t)int_fld[i];
+ kni_port_params_array[port_id]->nb_lcore_k = j;
+ }
+
+ print_config();
+
+ return 0;
+
+ fail:
+
+ for (i = 0; i < RTE_MAX_ETHPORTS; i++) {
+ if (kni_port_params_array[i]) {
+ rte_free(kni_port_params_array[i]);
+ kni_port_params_array[i] = NULL;
+ }
+ }
+
+ return -1;
+
+ }
+
+Packet Forwarding
+~~~~~~~~~~~~~~~~~
+
+After the initialization steps are completed, the main_loop() function is run on each lcore.
+This function first checks the lcore_id against the user provided lcore_rx and lcore_tx
+to see if this lcore is reading from or writing to kernel NIC interfaces.
+
+For the case that reads from a NIC port and writes to the kernel NIC interfaces,
+the packet reception is the same as in L2 Forwarding sample application
+(see :ref:`l2_fwd_app_rx_tx_packets`).
+The packet transmission is done by sending mbufs into the kernel NIC interfaces by rte_kni_tx_burst().
+The KNI library automatically frees the mbufs after the kernel successfully copied the mbufs.
+
+.. code-block:: c
+
+ /**
+ * Interface to burst rx and enqueue mbufs into rx_q
+ */
+
+ static void
+ kni_ingress(struct kni_port_params *p)
+ {
+ uint8_t i, nb_kni, port_id;
+ unsigned nb_rx, num;
+ struct rte_mbuf *pkts_burst[PKT_BURST_SZ];
+
+ if (p == NULL)
+ return;
+
+ nb_kni = p->nb_kni;
+ port_id = p->port_id;
+
+ for (i = 0; i < nb_kni; i++) {
+ /* Burst rx from eth */
+ nb_rx = rte_eth_rx_burst(port_id, 0, pkts_burst, PKT_BURST_SZ);
+ if (unlikely(nb_rx > PKT_BURST_SZ)) {
+ RTE_LOG(ERR, APP, "Error receiving from eth\n");
+ return;
+ }
+
+ /* Burst tx to kni */
+ num = rte_kni_tx_burst(p->kni[i], pkts_burst, nb_rx);
+ kni_stats[port_id].rx_packets += num;
+ rte_kni_handle_request(p->kni[i]);
+
+ if (unlikely(num < nb_rx)) {
+ /* Free mbufs not tx to kni interface */
+ kni_burst_free_mbufs(&pkts_burst[num], nb_rx - num);
+ kni_stats[port_id].rx_dropped += nb_rx - num;
+ }
+ }
+ }
+
+For the other case that reads from kernel NIC interfaces and writes to a physical NIC port, packets are retrieved by reading
+mbufs from kernel NIC interfaces by `rte_kni_rx_burst()`.
+The packet transmission is the same as in the L2 Forwarding sample application
+(see :ref:`l2_fwd_app_rx_tx_packets`).
+
+.. code-block:: c
+
+ /**
+ * Interface to dequeue mbufs from tx_q and burst tx
+ */
+
+ static void
+
+ kni_egress(struct kni_port_params *p)
+ {
+ uint8_t i, nb_kni, port_id;
+ unsigned nb_tx, num;
+ struct rte_mbuf *pkts_burst[PKT_BURST_SZ];
+
+ if (p == NULL)
+ return;
+
+ nb_kni = p->nb_kni;
+ port_id = p->port_id;
+
+ for (i = 0; i < nb_kni; i++) {
+ /* Burst rx from kni */
+ num = rte_kni_rx_burst(p->kni[i], pkts_burst, PKT_BURST_SZ);
+ if (unlikely(num > PKT_BURST_SZ)) {
+ RTE_LOG(ERR, APP, "Error receiving from KNI\n");
+ return;
+ }
+
+ /* Burst tx to eth */
+
+ nb_tx = rte_eth_tx_burst(port_id, 0, pkts_burst, (uint16_t)num);
+
+ kni_stats[port_id].tx_packets += nb_tx;
+
+ if (unlikely(nb_tx < num)) {
+ /* Free mbufs not tx to NIC */
+ kni_burst_free_mbufs(&pkts_burst[nb_tx], num - nb_tx);
+ kni_stats[port_id].tx_dropped += num - nb_tx;
+ }
+ }
+ }
+
+Callbacks for Kernel Requests
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+To execute specific PMD operations in user space requested by some Linux* commands,
+callbacks must be implemented and filled in the struct rte_kni_ops structure.
+Currently, setting a new MTU and configuring the network interface (up/ down) are supported.
+
+.. code-block:: c
+
+ static struct rte_kni_ops kni_ops = {
+ .change_mtu = kni_change_mtu,
+ .config_network_if = kni_config_network_interface,
+ };
+
+ /* Callback for request of changing MTU */
+
+ static int
+ kni_change_mtu(uint8_t port_id, unsigned new_mtu)
+ {
+ int ret;
+ struct rte_eth_conf conf;
+
+ if (port_id >= rte_eth_dev_count()) {
+ RTE_LOG(ERR, APP, "Invalid port id %d\n", port_id);
+ return -EINVAL;
+ }
+
+ RTE_LOG(INFO, APP, "Change MTU of port %d to %u\n", port_id, new_mtu);
+
+ /* Stop specific port */
+
+ rte_eth_dev_stop(port_id);
+
+ memcpy(&conf, &port_conf, sizeof(conf));
+
+ /* Set new MTU */
+
+ if (new_mtu > ETHER_MAX_LEN)
+ conf.rxmode.jumbo_frame = 1;
+ else
+ conf.rxmode.jumbo_frame = 0;
+
+ /* mtu + length of header + length of FCS = max pkt length */
+
+ conf.rxmode.max_rx_pkt_len = new_mtu + KNI_ENET_HEADER_SIZE + KNI_ENET_FCS_SIZE;
+
+ ret = rte_eth_dev_configure(port_id, 1, 1, &conf);
+ if (ret < 0) {
+ RTE_LOG(ERR, APP, "Fail to reconfigure port %d\n", port_id);
+ return ret;
+ }
+
+ /* Restart specific port */
+
+ ret = rte_eth_dev_start(port_id);
+ if (ret < 0) {
+ RTE_LOG(ERR, APP, "Fail to restart port %d\n", port_id);
+ return ret;
+ }
+
+ return 0;
+ }
+
+ /* Callback for request of configuring network interface up/down */
+
+ static int
+ kni_config_network_interface(uint8_t port_id, uint8_t if_up)
+ {
+ int ret = 0;
+
+ if (port_id >= rte_eth_dev_count() || port_id >= RTE_MAX_ETHPORTS) {
+ RTE_LOG(ERR, APP, "Invalid port id %d\n", port_id);
+ return -EINVAL;
+ }
+
+ RTE_LOG(INFO, APP, "Configure network interface of %d %s\n",
+
+ port_id, if_up ? "up" : "down");
+
+ if (if_up != 0) {
+ /* Configure network interface up */
+ rte_eth_dev_stop(port_id);
+ ret = rte_eth_dev_start(port_id);
+ } else /* Configure network interface down */
+ rte_eth_dev_stop(port_id);
+
+ if (ret < 0)
+ RTE_LOG(ERR, APP, "Failed to start port %d\n", port_id);
+ return ret;
+ }
Code Review / deb_dpdk.git / blobdiff