import 15.2.0 Octopus source

[ceph.git] / ceph / src / spdk / dpdk / examples / tep_termination / main.c

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2015 Intel Corporation
 */

#include <arpa/inet.h>
#include <getopt.h>
#include <linux/if_ether.h>
#include <linux/if_vlan.h>
#include <linux/virtio_net.h>
#include <linux/virtio_ring.h>
#include <signal.h>
#include <stdint.h>
#include <sys/eventfd.h>
#include <sys/param.h>
#include <unistd.h>

#include <rte_atomic.h>
#include <rte_cycles.h>
#include <rte_ethdev.h>
#include <rte_log.h>
#include <rte_string_fns.h>
#include <rte_malloc.h>
#include <rte_vhost.h>
#include <rte_pause.h>

#include "main.h"
#include "vxlan.h"
#include "vxlan_setup.h"

/* the maximum number of external ports supported */
#define MAX_SUP_PORTS 1

/**
 * Calculate the number of buffers needed per port
 */
#define NUM_MBUFS_PER_PORT ((MAX_QUEUES * RTE_TEST_RX_DESC_DEFAULT) +\
                                (nb_switching_cores * MAX_PKT_BURST) +\
                                (nb_switching_cores * \
                                RTE_TEST_TX_DESC_DEFAULT) +\
                                (nb_switching_cores * MBUF_CACHE_SIZE))

#define MBUF_CACHE_SIZE 128
#define MBUF_DATA_SIZE RTE_MBUF_DEFAULT_BUF_SIZE

#define MAX_PKT_BURST 32        /* Max burst size for RX/TX */
#define BURST_TX_DRAIN_US 100   /* TX drain every ~100us */

/* Defines how long we wait between retries on RX */
#define BURST_RX_WAIT_US 15

#define BURST_RX_RETRIES 4      /* Number of retries on RX. */

#define JUMBO_FRAME_MAX_SIZE    0x2600

/* State of virtio device. */
#define DEVICE_MAC_LEARNING 0
#define DEVICE_RX           1
#define DEVICE_SAFE_REMOVE  2

/* Config_core_flag status definitions. */
#define REQUEST_DEV_REMOVAL 1
#define ACK_DEV_REMOVAL     0

/* Configurable number of RX/TX ring descriptors */
#define RTE_TEST_RX_DESC_DEFAULT 1024
#define RTE_TEST_TX_DESC_DEFAULT 512

/* Get first 4 bytes in mbuf headroom. */
#define MBUF_HEADROOM_UINT32(mbuf) (*(uint32_t *)((uint8_t *)(mbuf) \
                + sizeof(struct rte_mbuf)))

#define INVALID_PORT_ID 0xFFFF

/* Maximum character device basename size. */
#define MAX_BASENAME_SZ 20

/* Maximum long option length for option parsing. */
#define MAX_LONG_OPT_SZ 64

/* Used to compare MAC addresses. */
#define MAC_ADDR_CMP 0xFFFFFFFFFFFFULL

#define CMD_LINE_OPT_NB_DEVICES "nb-devices"
#define CMD_LINE_OPT_UDP_PORT "udp-port"
#define CMD_LINE_OPT_TX_CHECKSUM "tx-checksum"
#define CMD_LINE_OPT_TSO_SEGSZ "tso-segsz"
#define CMD_LINE_OPT_FILTER_TYPE "filter-type"
#define CMD_LINE_OPT_ENCAP "encap"
#define CMD_LINE_OPT_DECAP "decap"
#define CMD_LINE_OPT_RX_RETRY "rx-retry"
#define CMD_LINE_OPT_RX_RETRY_DELAY "rx-retry-delay"
#define CMD_LINE_OPT_RX_RETRY_NUM "rx-retry-num"
#define CMD_LINE_OPT_STATS "stats"
#define CMD_LINE_OPT_DEV_BASENAME "dev-basename"

/* mask of enabled ports */
static uint32_t enabled_port_mask;

/*Number of switching cores enabled*/
static uint32_t nb_switching_cores;

/* number of devices/queues to support*/
uint16_t nb_devices = 2;

/* max ring descriptor, ixgbe, i40e, e1000 all are 4096. */
#define MAX_RING_DESC 4096

struct vpool {
        struct rte_mempool *pool;
        struct rte_ring *ring;
        uint32_t buf_size;
} vpool_array[MAX_QUEUES+MAX_QUEUES];

/* UDP tunneling port */
uint16_t udp_port = 4789;

/* enable/disable inner TX checksum */
uint8_t tx_checksum = 0;

/* TCP segment size */
uint16_t tso_segsz = 0;

/* enable/disable decapsulation */
uint8_t rx_decap = 1;

/* enable/disable encapsulation */
uint8_t tx_encap = 1;

/* RX filter type for tunneling packet */
uint8_t filter_idx = 1;

/* overlay packet operation */
struct ol_switch_ops overlay_options = {
        .port_configure = vxlan_port_init,
        .tunnel_setup = vxlan_link,
        .tunnel_destroy = vxlan_unlink,
        .tx_handle = vxlan_tx_pkts,
        .rx_handle = vxlan_rx_pkts,
        .param_handle = NULL,
};

/* Enable stats. */
uint32_t enable_stats = 0;
/* Enable retries on RX. */
static uint32_t enable_retry = 1;
/* Specify timeout (in useconds) between retries on RX. */
static uint32_t burst_rx_delay_time = BURST_RX_WAIT_US;
/* Specify the number of retries on RX. */
static uint32_t burst_rx_retry_num = BURST_RX_RETRIES;

/* Character device basename. Can be set by user. */
static char dev_basename[MAX_BASENAME_SZ] = "vhost-net";

static unsigned lcore_ids[RTE_MAX_LCORE];
uint16_t ports[RTE_MAX_ETHPORTS];

static unsigned nb_ports; /**< The number of ports specified in command line */

/* ethernet addresses of ports */
struct ether_addr ports_eth_addr[RTE_MAX_ETHPORTS];

/* heads for the main used and free linked lists for the data path. */
static struct virtio_net_data_ll *ll_root_used;
static struct virtio_net_data_ll *ll_root_free;

/**
 * Array of data core structures containing information on
 * individual core linked lists.
 */
static struct lcore_info lcore_info[RTE_MAX_LCORE];

/* Used for queueing bursts of TX packets. */
struct mbuf_table {
        unsigned len;
        unsigned txq_id;
        struct rte_mbuf *m_table[MAX_PKT_BURST];
};

/* TX queue for each data core. */
struct mbuf_table lcore_tx_queue[RTE_MAX_LCORE];

struct device_statistics dev_statistics[MAX_DEVICES];

/**
 * Set character device basename.
 */
static int
us_vhost_parse_basename(const char *q_arg)
{
        /* parse number string */
        if (strlen(q_arg) >= MAX_BASENAME_SZ)
                return -1;
        else
                strlcpy((char *)&dev_basename, q_arg, MAX_BASENAME_SZ);

        return 0;
}

/**
 * Parse the portmask provided at run time.
 */
static int
parse_portmask(const char *portmask)
{
        char *end = NULL;
        unsigned long pm;

        /* parse hexadecimal string */
        pm = strtoul(portmask, &end, 16);
        if ((portmask[0] == '\0') || (end == NULL) || (*end != '\0'))
                return -1;

        if (pm == 0)
                return -1;

        return pm;
}

/**
 * Parse num options at run time.
 */
static int
parse_num_opt(const char *q_arg, uint32_t max_valid_value)
{
        char *end = NULL;
        unsigned long num;

        /* parse unsigned int string */
        num = strtoul(q_arg, &end, 10);
        if ((q_arg[0] == '\0') || (end == NULL) || (*end != '\0'))
                return -1;

        if (num > max_valid_value)
                return -1;

        return num;
}

/**
 * Display usage
 */
static void
tep_termination_usage(const char *prgname)
{
        RTE_LOG(INFO, VHOST_CONFIG, "%s [EAL options] -- -p PORTMASK\n"
        "               --udp-port: UDP destination port for VXLAN packet\n"
        "               --nb-devices[1-64]: The number of virtIO device\n"
        "               --tx-checksum [0|1]: inner Tx checksum offload\n"
        "               --tso-segsz [0-N]: TCP segment size\n"
        "               --decap [0|1]: tunneling packet decapsulation\n"
        "               --encap [0|1]: tunneling packet encapsulation\n"
        "               --filter-type[1-3]: filter type for tunneling packet\n"
        "                   1: Inner MAC and tenent ID\n"
        "                   2: Inner MAC and VLAN, and tenent ID\n"
        "                   3: Outer MAC, Inner MAC and tenent ID\n"
        "               -p PORTMASK: Set mask for ports to be used by application\n"
        "               --rx-retry [0|1]: disable/enable(default) retries on rx."
        "                Enable retry if destintation queue is full\n"
        "               --rx-retry-delay [0-N]: timeout(in usecond) between retries on RX."
        "                This makes effect only if retries on rx enabled\n"
        "               --rx-retry-num [0-N]: the number of retries on rx."
        "                This makes effect only if retries on rx enabled\n"
        "               --stats [0-N]: 0: Disable stats, N: Time in seconds to print stats\n"
        "               --dev-basename: The basename to be used for the character device.\n",
               prgname);
}

/**
 * Parse the arguments given in the command line of the application.
 */
static int
tep_termination_parse_args(int argc, char **argv)
{
        int opt, ret;
        int option_index;
        unsigned i;
        const char *prgname = argv[0];
        static struct option long_option[] = {
                {CMD_LINE_OPT_NB_DEVICES, required_argument, NULL, 0},
                {CMD_LINE_OPT_UDP_PORT, required_argument, NULL, 0},
                {CMD_LINE_OPT_TX_CHECKSUM, required_argument, NULL, 0},
                {CMD_LINE_OPT_TSO_SEGSZ, required_argument, NULL, 0},
                {CMD_LINE_OPT_DECAP, required_argument, NULL, 0},
                {CMD_LINE_OPT_ENCAP, required_argument, NULL, 0},
                {CMD_LINE_OPT_FILTER_TYPE, required_argument, NULL, 0},
                {CMD_LINE_OPT_RX_RETRY, required_argument, NULL, 0},
                {CMD_LINE_OPT_RX_RETRY_DELAY, required_argument, NULL, 0},
                {CMD_LINE_OPT_RX_RETRY_NUM, required_argument, NULL, 0},
                {CMD_LINE_OPT_STATS, required_argument, NULL, 0},
                {CMD_LINE_OPT_DEV_BASENAME, required_argument, NULL, 0},
                {NULL, 0, 0, 0},
        };

        /* Parse command line */
        while ((opt = getopt_long(argc, argv, "p:",
                        long_option, &option_index)) != EOF) {
                switch (opt) {
                /* Portmask */
                case 'p':
                        enabled_port_mask = parse_portmask(optarg);
                        if (enabled_port_mask == 0) {
                                RTE_LOG(INFO, VHOST_CONFIG,
                                        "Invalid portmask\n");
                                tep_termination_usage(prgname);
                                return -1;
                        }
                        break;
                case 0:
                        if (!strncmp(long_option[option_index].name,
                                CMD_LINE_OPT_NB_DEVICES,
                                sizeof(CMD_LINE_OPT_NB_DEVICES))) {
                                ret = parse_num_opt(optarg, MAX_DEVICES);
                                if (ret == -1) {
                                        RTE_LOG(INFO, VHOST_CONFIG,
                                        "Invalid argument for nb-devices [0-%d]\n",
                                        MAX_DEVICES);
                                        tep_termination_usage(prgname);
                                        return -1;
                                } else
                                        nb_devices = ret;
                        }

                        /* Enable/disable retries on RX. */
                        if (!strncmp(long_option[option_index].name,
                                CMD_LINE_OPT_RX_RETRY,
                                sizeof(CMD_LINE_OPT_RX_RETRY))) {
                                ret = parse_num_opt(optarg, 1);
                                if (ret == -1) {
                                        RTE_LOG(INFO, VHOST_CONFIG,
                                                "Invalid argument for rx-retry [0|1]\n");
                                        tep_termination_usage(prgname);
                                        return -1;
                                } else
                                        enable_retry = ret;
                        }

                        if (!strncmp(long_option[option_index].name,
                                CMD_LINE_OPT_TSO_SEGSZ,
                                sizeof(CMD_LINE_OPT_TSO_SEGSZ))) {
                                ret = parse_num_opt(optarg, INT16_MAX);
                                if (ret == -1) {
                                        RTE_LOG(INFO, VHOST_CONFIG,
                                                "Invalid argument for TCP segment size [0-N]\n");
                                        tep_termination_usage(prgname);
                                        return -1;
                                } else
                                        tso_segsz = ret;
                        }

                        if (!strncmp(long_option[option_index].name,
                                        CMD_LINE_OPT_UDP_PORT,
                                        sizeof(CMD_LINE_OPT_UDP_PORT))) {
                                ret = parse_num_opt(optarg, INT16_MAX);
                                if (ret == -1) {
                                        RTE_LOG(INFO, VHOST_CONFIG,
                                                "Invalid argument for UDP port [0-N]\n");
                                        tep_termination_usage(prgname);
                                        return -1;
                                } else
                                        udp_port = ret;
                        }

                        /* Specify the retries delay time (in useconds) on RX.*/
                        if (!strncmp(long_option[option_index].name,
                                CMD_LINE_OPT_RX_RETRY_DELAY,
                                sizeof(CMD_LINE_OPT_RX_RETRY_DELAY))) {
                                ret = parse_num_opt(optarg, INT32_MAX);
                                if (ret == -1) {
                                        RTE_LOG(INFO, VHOST_CONFIG,
                                                "Invalid argument for rx-retry-delay [0-N]\n");
                                        tep_termination_usage(prgname);
                                        return -1;
                                } else
                                        burst_rx_delay_time = ret;
                        }

                        /* Specify the retries number on RX. */
                        if (!strncmp(long_option[option_index].name,
                                CMD_LINE_OPT_RX_RETRY_NUM,
                                sizeof(CMD_LINE_OPT_RX_RETRY_NUM))) {
                                ret = parse_num_opt(optarg, INT32_MAX);
                                if (ret == -1) {
                                        RTE_LOG(INFO, VHOST_CONFIG,
                                                "Invalid argument for rx-retry-num [0-N]\n");
                                        tep_termination_usage(prgname);
                                        return -1;
                                } else
                                        burst_rx_retry_num = ret;
                        }

                        if (!strncmp(long_option[option_index].name,
                                CMD_LINE_OPT_TX_CHECKSUM,
                                sizeof(CMD_LINE_OPT_TX_CHECKSUM))) {
                                ret = parse_num_opt(optarg, 1);
                                if (ret == -1) {
                                        RTE_LOG(INFO, VHOST_CONFIG,
                                                "Invalid argument for tx-checksum [0|1]\n");
                                        tep_termination_usage(prgname);
                                        return -1;
                                } else
                                        tx_checksum = ret;
                        }

                        if (!strncmp(long_option[option_index].name,
                                        CMD_LINE_OPT_FILTER_TYPE,
                                        sizeof(CMD_LINE_OPT_FILTER_TYPE))) {
                                ret = parse_num_opt(optarg, 3);
                                if ((ret == -1) || (ret == 0)) {
                                        RTE_LOG(INFO, VHOST_CONFIG,
                                                "Invalid argument for filter type [1-3]\n");
                                        tep_termination_usage(prgname);
                                        return -1;
                                } else
                                        filter_idx = ret - 1;
                        }

                        /* Enable/disable encapsulation on RX. */
                        if (!strncmp(long_option[option_index].name,
                                CMD_LINE_OPT_DECAP,
                                sizeof(CMD_LINE_OPT_DECAP))) {
                                ret = parse_num_opt(optarg, 1);
                                if (ret == -1) {
                                        RTE_LOG(INFO, VHOST_CONFIG,
                                                "Invalid argument for decap [0|1]\n");
                                        tep_termination_usage(prgname);
                                        return -1;
                                } else
                                        rx_decap = ret;
                        }

                        /* Enable/disable encapsulation on TX. */
                        if (!strncmp(long_option[option_index].name,
                                CMD_LINE_OPT_ENCAP,
                                sizeof(CMD_LINE_OPT_ENCAP))) {
                                ret = parse_num_opt(optarg, 1);
                                if (ret == -1) {
                                        RTE_LOG(INFO, VHOST_CONFIG,
                                                "Invalid argument for encap [0|1]\n");
                                        tep_termination_usage(prgname);
                                        return -1;
                                } else
                                        tx_encap = ret;
                        }

                        /* Enable/disable stats. */
                        if (!strncmp(long_option[option_index].name,
                                CMD_LINE_OPT_STATS,
                                sizeof(CMD_LINE_OPT_STATS))) {
                                ret = parse_num_opt(optarg, INT32_MAX);
                                if (ret == -1) {
                                        RTE_LOG(INFO, VHOST_CONFIG,
                                                        "Invalid argument for stats [0..N]\n");
                                        tep_termination_usage(prgname);
                                        return -1;
                                } else
                                        enable_stats = ret;
                        }

                        /* Set character device basename. */
                        if (!strncmp(long_option[option_index].name,
                                CMD_LINE_OPT_DEV_BASENAME,
                                sizeof(CMD_LINE_OPT_DEV_BASENAME))) {
                                if (us_vhost_parse_basename(optarg) == -1) {
                                        RTE_LOG(INFO, VHOST_CONFIG,
                                                "Invalid argument for character "
                                                "device basename (Max %d characters)\n",
                                                MAX_BASENAME_SZ);
                                        tep_termination_usage(prgname);
                                        return -1;
                                }
                        }

                        break;

                        /* Invalid option - print options. */
                default:
                        tep_termination_usage(prgname);
                        return -1;
                }
        }

        for (i = 0; i < RTE_MAX_ETHPORTS; i++) {
                if (enabled_port_mask & (1 << i))
                        ports[nb_ports++] = (uint8_t)i;
        }

        if ((nb_ports ==  0) || (nb_ports > MAX_SUP_PORTS)) {
                RTE_LOG(INFO, VHOST_PORT, "Current enabled port number is %u,"
                        "but only %u port can be enabled\n", nb_ports,
                        MAX_SUP_PORTS);
                return -1;
        }

        return 0;
}

/**
 * Update the global var NB_PORTS and array PORTS
 * according to system ports number and return valid ports number
 */
static unsigned
check_ports_num(unsigned max_nb_ports)
{
        unsigned valid_nb_ports = nb_ports;
        unsigned portid;

        if (nb_ports > max_nb_ports) {
                RTE_LOG(INFO, VHOST_PORT, "\nSpecified port number(%u) "
                        " exceeds total system port number(%u)\n",
                        nb_ports, max_nb_ports);
                nb_ports = max_nb_ports;
        }

        for (portid = 0; portid < nb_ports; portid++) {
                if (!rte_eth_dev_is_valid_port(ports[portid])) {
                        RTE_LOG(INFO, VHOST_PORT,
                                "\nSpecified port ID(%u) is not valid\n",
                                ports[portid]);
                        ports[portid] = INVALID_PORT_ID;
                        valid_nb_ports--;
                }
        }
        return valid_nb_ports;
}

/**
 * This function routes the TX packet to the correct interface. This may be a local device
 * or the physical port.
 */
static __rte_always_inline void
virtio_tx_route(struct vhost_dev *vdev, struct rte_mbuf *m)
{
        struct mbuf_table *tx_q;
        struct rte_mbuf **m_table;
        unsigned len, ret = 0;
        const uint16_t lcore_id = rte_lcore_id();

        RTE_LOG_DP(DEBUG, VHOST_DATA, "(%d) TX: MAC address is external\n",
                vdev->vid);

        /* Add packet to the port tx queue */
        tx_q = &lcore_tx_queue[lcore_id];
        len = tx_q->len;

        tx_q->m_table[len] = m;
        len++;
        if (enable_stats) {
                dev_statistics[vdev->vid].tx_total++;
                dev_statistics[vdev->vid].tx++;
        }

        if (unlikely(len == MAX_PKT_BURST)) {
                m_table = (struct rte_mbuf **)tx_q->m_table;
                ret = overlay_options.tx_handle(ports[0],
                        (uint16_t)tx_q->txq_id, m_table,
                        (uint16_t)tx_q->len);

                /* Free any buffers not handled by TX and update
                 * the port stats.
                 */
                if (unlikely(ret < len)) {
                        do {
                                rte_pktmbuf_free(m_table[ret]);
                        } while (++ret < len);
                }

                len = 0;
        }

        tx_q->len = len;
        return;
}

/**
 * This function is called by each data core. It handles all
 * RX/TX registered with the core. For TX the specific lcore
 * linked list is used. For RX, MAC addresses are compared
 * with all devices in the main linked list.
 */
static int
switch_worker(__rte_unused void *arg)
{
        struct rte_mempool *mbuf_pool = arg;
        struct vhost_dev *vdev = NULL;
        struct rte_mbuf *pkts_burst[MAX_PKT_BURST];
        struct virtio_net_data_ll *dev_ll;
        struct mbuf_table *tx_q;
        volatile struct lcore_ll_info *lcore_ll;
        const uint64_t drain_tsc = (rte_get_tsc_hz() + US_PER_S - 1)
                                        / US_PER_S * BURST_TX_DRAIN_US;
        uint64_t prev_tsc, diff_tsc, cur_tsc, ret_count = 0;
        unsigned i, ret = 0;
        const uint16_t lcore_id = rte_lcore_id();
        const uint16_t num_cores = (uint16_t)rte_lcore_count();
        uint16_t rx_count = 0;
        uint16_t tx_count;
        uint32_t retry = 0;

        RTE_LOG(INFO, VHOST_DATA, "Procesing on Core %u started\n", lcore_id);
        lcore_ll = lcore_info[lcore_id].lcore_ll;
        prev_tsc = 0;

        tx_q = &lcore_tx_queue[lcore_id];
        for (i = 0; i < num_cores; i++) {
                if (lcore_ids[i] == lcore_id) {
                        tx_q->txq_id = i;
                        break;
                }
        }

        while (1) {
                cur_tsc = rte_rdtsc();
                /*
                 * TX burst queue drain
                 */
                diff_tsc = cur_tsc - prev_tsc;
                if (unlikely(diff_tsc > drain_tsc)) {

                        if (tx_q->len) {
                                RTE_LOG_DP(DEBUG, VHOST_DATA, "TX queue drained after "
                                        "timeout with burst size %u\n",
                                        tx_q->len);
                                ret = overlay_options.tx_handle(ports[0],
                                        (uint16_t)tx_q->txq_id,
                                        (struct rte_mbuf **)tx_q->m_table,
                                        (uint16_t)tx_q->len);
                                if (unlikely(ret < tx_q->len)) {
                                        do {
                                                rte_pktmbuf_free(tx_q->m_table[ret]);
                                        } while (++ret < tx_q->len);
                                }

                                tx_q->len = 0;
                        }

                        prev_tsc = cur_tsc;

                }

                rte_prefetch0(lcore_ll->ll_root_used);

                /**
                 * Inform the configuration core that we have exited
                 * the linked list and that no devices are
                 * in use if requested.
                 */
                if (lcore_ll->dev_removal_flag == REQUEST_DEV_REMOVAL)
                        lcore_ll->dev_removal_flag = ACK_DEV_REMOVAL;

                /*
                 * Process devices
                 */
                dev_ll = lcore_ll->ll_root_used;

                while (dev_ll != NULL) {
                        vdev = dev_ll->vdev;

                        if (unlikely(vdev->remove)) {
                                dev_ll = dev_ll->next;
                                overlay_options.tunnel_destroy(vdev);
                                vdev->ready = DEVICE_SAFE_REMOVE;
                                continue;
                        }
                        if (likely(vdev->ready == DEVICE_RX)) {
                                /* Handle guest RX */
                                rx_count = rte_eth_rx_burst(ports[0],
                                        vdev->rx_q, pkts_burst, MAX_PKT_BURST);

                                if (rx_count) {
                                        /*
                                        * Retry is enabled and the queue is
                                        * full then we wait and retry to
                                        * avoid packet loss. Here MAX_PKT_BURST
                                        * must be less than virtio queue size
                                        */
                                        if (enable_retry && unlikely(rx_count >
                                                rte_vhost_avail_entries(vdev->vid, VIRTIO_RXQ))) {
                                                for (retry = 0; retry < burst_rx_retry_num;
                                                        retry++) {
                                                        rte_delay_us(burst_rx_delay_time);
                                                        if (rx_count <= rte_vhost_avail_entries(vdev->vid, VIRTIO_RXQ))
                                                                break;
                                                }
                                        }

                                        ret_count = overlay_options.rx_handle(vdev->vid, pkts_burst, rx_count);
                                        if (enable_stats) {
                                                rte_atomic64_add(
                                                &dev_statistics[vdev->vid].rx_total_atomic,
                                                rx_count);
                                                rte_atomic64_add(
                                                &dev_statistics[vdev->vid].rx_atomic, ret_count);
                                        }
                                        while (likely(rx_count)) {
                                                rx_count--;
                                                rte_pktmbuf_free(pkts_burst[rx_count]);
                                        }

                                }
                        }

                        if (likely(!vdev->remove)) {
                                /* Handle guest TX*/
                                tx_count = rte_vhost_dequeue_burst(vdev->vid,
                                                VIRTIO_TXQ, mbuf_pool,
                                                pkts_burst, MAX_PKT_BURST);
                                /* If this is the first received packet we need to learn the MAC */
                                if (unlikely(vdev->ready == DEVICE_MAC_LEARNING) && tx_count) {
                                        if (vdev->remove ||
                                                (overlay_options.tunnel_setup(vdev, pkts_burst[0]) == -1)) {
                                                while (tx_count)
                                                        rte_pktmbuf_free(pkts_burst[--tx_count]);
                                        }
                                }
                                while (tx_count)
                                        virtio_tx_route(vdev, pkts_burst[--tx_count]);
                        }

                        /* move to the next device in the list */
                        dev_ll = dev_ll->next;
                }
        }

        return 0;
}

/**
 * Add an entry to a used linked list. A free entry must first be found
 * in the free linked list using get_data_ll_free_entry();
 */
static void
add_data_ll_entry(struct virtio_net_data_ll **ll_root_addr,
        struct virtio_net_data_ll *ll_dev)
{
        struct virtio_net_data_ll *ll = *ll_root_addr;

        /* Set next as NULL and use a compiler barrier to avoid reordering. */
        ll_dev->next = NULL;
        rte_compiler_barrier();

        /* If ll == NULL then this is the first device. */
        if (ll) {
                /* Increment to the tail of the linked list. */
                while (ll->next != NULL)
                        ll = ll->next;

                ll->next = ll_dev;
        } else {
                *ll_root_addr = ll_dev;
        }
}

/**
 * Remove an entry from a used linked list. The entry must then be added to
 * the free linked list using put_data_ll_free_entry().
 */
static void
rm_data_ll_entry(struct virtio_net_data_ll **ll_root_addr,
        struct virtio_net_data_ll *ll_dev,
        struct virtio_net_data_ll *ll_dev_last)
{
        struct virtio_net_data_ll *ll = *ll_root_addr;

        if (unlikely((ll == NULL) || (ll_dev == NULL)))
                return;

        if (ll_dev == ll)
                *ll_root_addr = ll_dev->next;
        else
                if (likely(ll_dev_last != NULL))
                        ll_dev_last->next = ll_dev->next;
                else
                        RTE_LOG(ERR, VHOST_CONFIG,
                                "Remove entry form ll failed.\n");
}

/**
 * Find and return an entry from the free linked list.
 */
static struct virtio_net_data_ll *
get_data_ll_free_entry(struct virtio_net_data_ll **ll_root_addr)
{
        struct virtio_net_data_ll *ll_free = *ll_root_addr;
        struct virtio_net_data_ll *ll_dev;

        if (ll_free == NULL)
                return NULL;

        ll_dev = ll_free;
        *ll_root_addr = ll_free->next;

        return ll_dev;
}

/**
 * Place an entry back on to the free linked list.
 */
static void
put_data_ll_free_entry(struct virtio_net_data_ll **ll_root_addr,
        struct virtio_net_data_ll *ll_dev)
{
        struct virtio_net_data_ll *ll_free = *ll_root_addr;

        if (ll_dev == NULL)
                return;

        ll_dev->next = ll_free;
        *ll_root_addr = ll_dev;
}

/**
 * Creates a linked list of a given size.
 */
static struct virtio_net_data_ll *
alloc_data_ll(uint32_t size)
{
        struct virtio_net_data_ll *ll_new;
        uint32_t i;

        /* Malloc and then chain the linked list. */
        ll_new = malloc(size * sizeof(struct virtio_net_data_ll));
        if (ll_new == NULL) {
                RTE_LOG(ERR, VHOST_CONFIG,
                        "Failed to allocate memory for ll_new.\n");
                return NULL;
        }

        for (i = 0; i < size - 1; i++) {
                ll_new[i].vdev = NULL;
                ll_new[i].next = &ll_new[i+1];
        }
        ll_new[i].next = NULL;

        return ll_new;
}

/**
 * Create the main linked list along with each individual cores
 * linked list. A used and a free list are created to manage entries.
 */
static int
init_data_ll(void)
{
        int lcore;

        RTE_LCORE_FOREACH_SLAVE(lcore) {
                lcore_info[lcore].lcore_ll =
                        malloc(sizeof(struct lcore_ll_info));
                if (lcore_info[lcore].lcore_ll == NULL) {
                        RTE_LOG(ERR, VHOST_CONFIG,
                                "Failed to allocate memory for lcore_ll.\n");
                        return -1;
                }

                lcore_info[lcore].lcore_ll->device_num = 0;
                lcore_info[lcore].lcore_ll->dev_removal_flag = ACK_DEV_REMOVAL;
                lcore_info[lcore].lcore_ll->ll_root_used = NULL;
                if (nb_devices % nb_switching_cores)
                        lcore_info[lcore].lcore_ll->ll_root_free =
                                alloc_data_ll((nb_devices / nb_switching_cores)
                                                + 1);
                else
                        lcore_info[lcore].lcore_ll->ll_root_free =
                                alloc_data_ll(nb_devices / nb_switching_cores);
        }

        /* Allocate devices up to a maximum of MAX_DEVICES. */
        ll_root_free = alloc_data_ll(MIN((nb_devices), MAX_DEVICES));

        return 0;
}

/**
 * Remove a device from the specific data core linked list and
 * from the main linked list. Synchonization occurs through the use
 * of the lcore dev_removal_flag.
 */
static void
destroy_device(int vid)
{
        struct virtio_net_data_ll *ll_lcore_dev_cur;
        struct virtio_net_data_ll *ll_main_dev_cur;
        struct virtio_net_data_ll *ll_lcore_dev_last = NULL;
        struct virtio_net_data_ll *ll_main_dev_last = NULL;
        struct vhost_dev *vdev = NULL;
        int lcore;

        ll_main_dev_cur = ll_root_used;
        while (ll_main_dev_cur != NULL) {
                if (ll_main_dev_cur->vdev->vid == vid) {
                        vdev = ll_main_dev_cur->vdev;
                        break;
                }
        }
        if (!vdev)
                return;

        /* set the remove flag. */
        vdev->remove = 1;
        while (vdev->ready != DEVICE_SAFE_REMOVE)
                rte_pause();

        /* Search for entry to be removed from lcore ll */
        ll_lcore_dev_cur = lcore_info[vdev->coreid].lcore_ll->ll_root_used;
        while (ll_lcore_dev_cur != NULL) {
                if (ll_lcore_dev_cur->vdev == vdev) {
                        break;
                } else {
                        ll_lcore_dev_last = ll_lcore_dev_cur;
                        ll_lcore_dev_cur = ll_lcore_dev_cur->next;
                }
        }

        if (ll_lcore_dev_cur == NULL) {
                RTE_LOG(ERR, VHOST_CONFIG,
                        "(%d) Failed to find the dev to be destroy.\n", vid);
                return;
        }

        /* Search for entry to be removed from main ll */
        ll_main_dev_cur = ll_root_used;
        ll_main_dev_last = NULL;
        while (ll_main_dev_cur != NULL) {
                if (ll_main_dev_cur->vdev == vdev) {
                        break;
                } else {
                        ll_main_dev_last = ll_main_dev_cur;
                        ll_main_dev_cur = ll_main_dev_cur->next;
                }
        }

        /* Remove entries from the lcore and main ll. */
        rm_data_ll_entry(&lcore_info[vdev->coreid].lcore_ll->ll_root_used,
                        ll_lcore_dev_cur, ll_lcore_dev_last);
        rm_data_ll_entry(&ll_root_used, ll_main_dev_cur, ll_main_dev_last);

        /* Set the dev_removal_flag on each lcore. */
        RTE_LCORE_FOREACH_SLAVE(lcore) {
                lcore_info[lcore].lcore_ll->dev_removal_flag =
                        REQUEST_DEV_REMOVAL;
        }

        /*
         * Once each core has set the dev_removal_flag to
         * ACK_DEV_REMOVAL we can be sure that they can no longer access
         * the device removed from the linked lists and that the devices
         * are no longer in use.
         */
        RTE_LCORE_FOREACH_SLAVE(lcore) {
                while (lcore_info[lcore].lcore_ll->dev_removal_flag
                        != ACK_DEV_REMOVAL)
                        rte_pause();
        }

        /* Add the entries back to the lcore and main free ll.*/
        put_data_ll_free_entry(&lcore_info[vdev->coreid].lcore_ll->ll_root_free,
                                ll_lcore_dev_cur);
        put_data_ll_free_entry(&ll_root_free, ll_main_dev_cur);

        /* Decrement number of device on the lcore. */
        lcore_info[vdev->coreid].lcore_ll->device_num--;

        RTE_LOG(INFO, VHOST_DATA, "(%d) Device has been removed "
                "from data core\n", vid);

        rte_free(vdev);

}

/**
 * A new device is added to a data core. First the device is added
 * to the main linked list and the allocated to a specific data core.
 */
static int
new_device(int vid)
{
        struct virtio_net_data_ll *ll_dev;
        int lcore, core_add = 0;
        uint32_t device_num_min = nb_devices;
        struct vhost_dev *vdev;

        vdev = rte_zmalloc("vhost device", sizeof(*vdev), RTE_CACHE_LINE_SIZE);
        if (vdev == NULL) {
                RTE_LOG(INFO, VHOST_DATA,
                        "(%d) Couldn't allocate memory for vhost dev\n", vid);
                return -1;
        }
        vdev->vid = vid;
        /* Add device to main ll */
        ll_dev = get_data_ll_free_entry(&ll_root_free);
        if (ll_dev == NULL) {
                RTE_LOG(INFO, VHOST_DATA, "(%d) No free entry found in"
                        " linked list Device limit of %d devices per core"
                        " has been reached\n", vid, nb_devices);
                if (vdev->regions_hpa)
                        rte_free(vdev->regions_hpa);
                rte_free(vdev);
                return -1;
        }
        ll_dev->vdev = vdev;
        add_data_ll_entry(&ll_root_used, ll_dev);
        vdev->rx_q = vid;

        /* reset ready flag */
        vdev->ready = DEVICE_MAC_LEARNING;
        vdev->remove = 0;

        /* Find a suitable lcore to add the device. */
        RTE_LCORE_FOREACH_SLAVE(lcore) {
                if (lcore_info[lcore].lcore_ll->device_num < device_num_min) {
                        device_num_min = lcore_info[lcore].lcore_ll->device_num;
                        core_add = lcore;
                }
        }
        /* Add device to lcore ll */
        ll_dev = get_data_ll_free_entry(&lcore_info[core_add].lcore_ll->ll_root_free);
        if (ll_dev == NULL) {
                RTE_LOG(INFO, VHOST_DATA,
                        "(%d) Failed to add device to data core\n",
                        vid);
                vdev->ready = DEVICE_SAFE_REMOVE;
                destroy_device(vid);
                rte_free(vdev->regions_hpa);
                rte_free(vdev);
                return -1;
        }
        ll_dev->vdev = vdev;
        vdev->coreid = core_add;

        add_data_ll_entry(&lcore_info[vdev->coreid].lcore_ll->ll_root_used,
                        ll_dev);

        /* Initialize device stats */
        memset(&dev_statistics[vid], 0,
                sizeof(struct device_statistics));

        /* Disable notifications. */
        rte_vhost_enable_guest_notification(vid, VIRTIO_RXQ, 0);
        rte_vhost_enable_guest_notification(vid, VIRTIO_TXQ, 0);
        lcore_info[vdev->coreid].lcore_ll->device_num++;

        RTE_LOG(INFO, VHOST_DATA, "(%d) Device has been added to data core %d\n",
                vid, vdev->coreid);

        return 0;
}

/**
 * These callback allow devices to be added to the data core when configuration
 * has been fully complete.
 */
static const struct vhost_device_ops virtio_net_device_ops = {
        .new_device =  new_device,
        .destroy_device = destroy_device,
};

/**
 * This is a thread will wake up after a period to print stats if the user has
 * enabled them.
 */
static void *
print_stats(__rte_unused void *arg)
{
        struct virtio_net_data_ll *dev_ll;
        uint64_t tx_dropped, rx_dropped;
        uint64_t tx, tx_total, rx, rx_total, rx_ip_csum, rx_l4_csum;
        int vid;
        const char clr[] = { 27, '[', '2', 'J', '\0' };
        const char top_left[] = { 27, '[', '1', ';', '1', 'H', '\0' };

        while (1) {
                sleep(enable_stats);

                /* Clear screen and move to top left */
                printf("%s%s", clr, top_left);

                printf("\nDevice statistics ================================");

                dev_ll = ll_root_used;
                while (dev_ll != NULL) {
                        vid = dev_ll->vdev->vid;
                        tx_total = dev_statistics[vid].tx_total;
                        tx = dev_statistics[vid].tx;
                        tx_dropped = tx_total - tx;

                        rx_total = rte_atomic64_read(
                                &dev_statistics[vid].rx_total_atomic);
                        rx = rte_atomic64_read(
                                &dev_statistics[vid].rx_atomic);
                        rx_dropped = rx_total - rx;
                        rx_ip_csum = rte_atomic64_read(
                                &dev_statistics[vid].rx_bad_ip_csum);
                        rx_l4_csum = rte_atomic64_read(
                                &dev_statistics[vid].rx_bad_l4_csum);

                        printf("\nStatistics for device %d ----------"
                                        "\nTX total:            %"PRIu64""
                                        "\nTX dropped:          %"PRIu64""
                                        "\nTX successful:               %"PRIu64""
                                        "\nRX total:            %"PRIu64""
                                        "\nRX bad IP csum:      %"PRIu64""
                                        "\nRX bad L4 csum:      %"PRIu64""
                                        "\nRX dropped:          %"PRIu64""
                                        "\nRX successful:               %"PRIu64"",
                                        vid,
                                        tx_total,
                                        tx_dropped,
                                        tx,
                                        rx_total,
                                        rx_ip_csum,
                                        rx_l4_csum,
                                        rx_dropped,
                                        rx);

                        dev_ll = dev_ll->next;
                }
                printf("\n================================================\n");
        }

        return NULL;
}

/**
 * Main function, does initialisation and calls the per-lcore functions.
 */
int
main(int argc, char *argv[])
{
        struct rte_mempool *mbuf_pool = NULL;
        unsigned lcore_id, core_id = 0;
        unsigned nb_ports, valid_nb_ports;
        int ret;
        uint16_t portid;
        uint16_t queue_id;
        static pthread_t tid;

        /* init EAL */
        ret = rte_eal_init(argc, argv);
        if (ret < 0)
                rte_exit(EXIT_FAILURE, "Error with EAL initialization\n");
        argc -= ret;
        argv += ret;

        /* parse app arguments */
        ret = tep_termination_parse_args(argc, argv);
        if (ret < 0)
                rte_exit(EXIT_FAILURE, "Invalid argument\n");

        for (lcore_id = 0; lcore_id < RTE_MAX_LCORE; lcore_id++)
                if (rte_lcore_is_enabled(lcore_id))
                        lcore_ids[core_id++] = lcore_id;

        /* set the number of swithcing cores available */
        nb_switching_cores = rte_lcore_count()-1;

        /* Get the number of physical ports. */
        nb_ports = rte_eth_dev_count_avail();

        /*
         * Update the global var NB_PORTS and global array PORTS
         * and get value of var VALID_NB_PORTS according to system ports number
         */
        valid_nb_ports = check_ports_num(nb_ports);

        if ((valid_nb_ports == 0) || (valid_nb_ports > MAX_SUP_PORTS)) {
                rte_exit(EXIT_FAILURE, "Current enabled port number is %u,"
                        "but only %u port can be enabled\n", nb_ports,
                        MAX_SUP_PORTS);
        }
        /* Create the mbuf pool. */
        mbuf_pool = rte_pktmbuf_pool_create(
                        "MBUF_POOL",
                        NUM_MBUFS_PER_PORT * valid_nb_ports,
                        MBUF_CACHE_SIZE,
                        0,
                        MBUF_DATA_SIZE,
                        rte_socket_id());
        if (mbuf_pool == NULL)
                rte_exit(EXIT_FAILURE, "Cannot create mbuf pool\n");

        for (queue_id = 0; queue_id < MAX_QUEUES + 1; queue_id++)
                vpool_array[queue_id].pool = mbuf_pool;

        /* initialize all ports */
        RTE_ETH_FOREACH_DEV(portid) {
                /* skip ports that are not enabled */
                if ((enabled_port_mask & (1 << portid)) == 0) {
                        RTE_LOG(INFO, VHOST_PORT,
                                "Skipping disabled port %d\n", portid);
                        continue;
                }
                if (overlay_options.port_configure(portid, mbuf_pool) != 0)
                        rte_exit(EXIT_FAILURE,
                                "Cannot initialize network ports\n");
        }

        /* Initialise all linked lists. */
        if (init_data_ll() == -1)
                rte_exit(EXIT_FAILURE, "Failed to initialize linked list\n");

        /* Initialize device stats */
        memset(&dev_statistics, 0, sizeof(dev_statistics));

        /* Enable stats if the user option is set. */
        if (enable_stats) {
                ret = rte_ctrl_thread_create(&tid, "print-stats", NULL,
                                        print_stats, NULL);
                if (ret < 0)
                        rte_exit(EXIT_FAILURE, "Cannot create print-stats thread\n");
        }

        /* Launch all data cores. */
        RTE_LCORE_FOREACH_SLAVE(lcore_id) {
                rte_eal_remote_launch(switch_worker,
                        mbuf_pool, lcore_id);
        }

        ret = rte_vhost_driver_register((char *)&dev_basename, 0);
        if (ret != 0)
                rte_exit(EXIT_FAILURE, "failed to register vhost driver.\n");

        rte_vhost_driver_disable_features(dev_basename,
                1ULL << VIRTIO_NET_F_MRG_RXBUF);

        ret = rte_vhost_driver_callback_register(dev_basename,
                &virtio_net_device_ops);
        if (ret != 0) {
                rte_exit(EXIT_FAILURE,
                        "failed to register vhost driver callbacks.\n");
        }

        if (rte_vhost_driver_start(dev_basename) < 0) {
                rte_exit(EXIT_FAILURE,
                        "failed to start vhost driver.\n");
        }

        RTE_LCORE_FOREACH_SLAVE(lcore_id)
                rte_eal_wait_lcore(lcore_id);

        return 0;
}