examples/vhost/main.c

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright(c) 2010-2017 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_cycles.h>
#include <rte_ethdev.h>
#include <rte_log.h>
#include <rte_string_fns.h>
#include <rte_malloc.h>
#include <rte_net.h>
#include <rte_vhost.h>
#include <rte_ip.h>
#include <rte_tcp.h>
#include <rte_pause.h>
#include <rte_dmadev.h>
#include <rte_vhost_async.h>

#include "main.h"

#ifndef MAX_QUEUES
#define MAX_QUEUES 128
#endif

#define NUM_MBUFS_DEFAULT 0x24000

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

#define MBUF_CACHE_SIZE 128
#define MBUF_DATA_SIZE  RTE_MBUF_DEFAULT_BUF_SIZE

#define BURST_TX_DRAIN_US 100   /* TX drain every ~100us */

#define BURST_RX_WAIT_US 15 /* Defines how long we wait between retries on RX */
#define BURST_RX_RETRIES 4      /* Number of retries on RX. */

#define JUMBO_FRAME_MAX_SIZE    0x2600
#define MAX_MTU (JUMBO_FRAME_MAX_SIZE - (RTE_ETHER_HDR_LEN + RTE_ETHER_CRC_LEN))

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

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

#define INVALID_PORT_ID 0xFF
#define INVALID_DMA_ID -1

#define DMA_RING_SIZE 4096

/* number of mbufs in all pools - if specified on command-line. */
static int total_num_mbufs = NUM_MBUFS_DEFAULT;

struct dma_for_vhost dma_bind[RTE_MAX_VHOST_DEVICE];
int16_t dmas_id[RTE_DMADEV_DEFAULT_MAX];
static int dma_count;

/* mask of enabled ports */
static uint32_t enabled_port_mask = 0;

/* Promiscuous mode */
static uint32_t promiscuous;

/* number of devices/queues to support*/
static uint32_t num_queues = 0;
static uint32_t num_devices;

static struct rte_mempool *mbuf_pool;
static int mergeable;

/* Enable VM2VM communications. If this is disabled then the MAC address compare is skipped. */
typedef enum {
    VM2VM_DISABLED = 0,
    VM2VM_SOFTWARE = 1,
    VM2VM_HARDWARE = 2,
    VM2VM_LAST
} vm2vm_type;
static vm2vm_type vm2vm_mode = VM2VM_SOFTWARE;

/* Enable stats. */
static uint32_t enable_stats = 0;
/* Enable retries on RX. */
static uint32_t enable_retry = 1;

/* Disable TX checksum offload */
static uint32_t enable_tx_csum;

/* Disable TSO offload */
static uint32_t enable_tso;

static int client_mode;

static int builtin_net_driver;

/* 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;

/* Socket file paths. Can be set by user */
static char *socket_files;
static int nb_sockets;

/* empty VMDq configuration structure. Filled in programmatically */
static struct rte_eth_conf vmdq_conf_default = {
    .rxmode = {
        .mq_mode        = RTE_ETH_MQ_RX_VMDQ_ONLY,
        .split_hdr_size = 0,
        /*
         * VLAN strip is necessary for 1G NIC such as I350,
         * this fixes bug of ipv4 forwarding in guest can't
         * forward packets from one virtio dev to another virtio dev.
         */
        .offloads = RTE_ETH_RX_OFFLOAD_VLAN_STRIP,
    },

    .txmode = {
        .mq_mode = RTE_ETH_MQ_TX_NONE,
        .offloads = (RTE_ETH_TX_OFFLOAD_IPV4_CKSUM |
                 RTE_ETH_TX_OFFLOAD_TCP_CKSUM |
                 RTE_ETH_TX_OFFLOAD_VLAN_INSERT |
                 RTE_ETH_TX_OFFLOAD_MULTI_SEGS |
                 RTE_ETH_TX_OFFLOAD_TCP_TSO),
    },
    .rx_adv_conf = {
        /*
         * should be overridden separately in code with
         * appropriate values
         */
        .vmdq_rx_conf = {
            .nb_queue_pools = RTE_ETH_8_POOLS,
            .enable_default_pool = 0,
            .default_pool = 0,
            .nb_pool_maps = 0,
            .pool_map = {{0, 0},},
        },
    },
};


static unsigned lcore_ids[RTE_MAX_LCORE];
static uint16_t ports[RTE_MAX_ETHPORTS];
static unsigned num_ports = 0; 
static uint16_t num_pf_queues, num_vmdq_queues;
static uint16_t vmdq_pool_base, vmdq_queue_base;
static uint16_t queues_per_pool;

const uint16_t vlan_tags[] = {
    1000, 1001, 1002, 1003, 1004, 1005, 1006, 1007,
    1008, 1009, 1010, 1011, 1012, 1013, 1014, 1015,
    1016, 1017, 1018, 1019, 1020, 1021, 1022, 1023,
    1024, 1025, 1026, 1027, 1028, 1029, 1030, 1031,
    1032, 1033, 1034, 1035, 1036, 1037, 1038, 1039,
    1040, 1041, 1042, 1043, 1044, 1045, 1046, 1047,
    1048, 1049, 1050, 1051, 1052, 1053, 1054, 1055,
    1056, 1057, 1058, 1059, 1060, 1061, 1062, 1063,
};

/* ethernet addresses of ports */
static struct rte_ether_addr vmdq_ports_eth_addr[RTE_MAX_ETHPORTS];

static struct vhost_dev_tailq_list vhost_dev_list =
    TAILQ_HEAD_INITIALIZER(vhost_dev_list);

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];
};

struct vhost_bufftable {
    uint32_t len;
    uint64_t pre_tsc;
    struct rte_mbuf *m_table[MAX_PKT_BURST];
};

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

/*
 * Vhost TX buffer for each data core.
 * Every data core maintains a TX buffer for every vhost device,
 * which is used for batch pkts enqueue for higher performance.
 */
struct vhost_bufftable *vhost_txbuff[RTE_MAX_LCORE * RTE_MAX_VHOST_DEVICE];

#define MBUF_TABLE_DRAIN_TSC    ((rte_get_tsc_hz() + US_PER_S - 1) \
                 / US_PER_S * BURST_TX_DRAIN_US)

static inline bool
is_dma_configured(int16_t dev_id)
{
    int i;

    for (i = 0; i < dma_count; i++)
        if (dmas_id[i] == dev_id)
            return true;
    return false;
}

static inline int
open_dma(const char *value)
{
    struct dma_for_vhost *dma_info = dma_bind;
    char *input = strndup(value, strlen(value) + 1);
    char *addrs = input;
    char *ptrs[2];
    char *start, *end, *substr;
    int64_t vid;

    struct rte_dma_info info;
    struct rte_dma_conf dev_config = { .nb_vchans = 1 };
    struct rte_dma_vchan_conf qconf = {
        .direction = RTE_DMA_DIR_MEM_TO_MEM,
        .nb_desc = DMA_RING_SIZE
    };

    int dev_id;
    int ret = 0;
    uint16_t i = 0;
    char *dma_arg[RTE_MAX_VHOST_DEVICE];
    int args_nr;

    while (isblank(*addrs))
        addrs++;
    if (*addrs == '\0') {
        ret = -1;
        goto out;
    }

    /* process DMA devices within bracket. */
    addrs++;
    substr = strtok(addrs, ";]");
    if (!substr) {
        ret = -1;
        goto out;
    }

    args_nr = rte_strsplit(substr, strlen(substr), dma_arg, RTE_MAX_VHOST_DEVICE, ',');
    if (args_nr <= 0) {
        ret = -1;
        goto out;
    }

    while (i < args_nr) {
        char *arg_temp = dma_arg[i];
        uint8_t sub_nr;

        sub_nr = rte_strsplit(arg_temp, strlen(arg_temp), ptrs, 2, '@');
        if (sub_nr != 2) {
            ret = -1;
            goto out;
        }

        start = strstr(ptrs[0], "txd");
        if (start == NULL) {
            ret = -1;
            goto out;
        }

        start += 3;
        vid = strtol(start, &end, 0);
        if (end == start) {
            ret = -1;
            goto out;
        }

        dev_id = rte_dma_get_dev_id_by_name(ptrs[1]);
        if (dev_id < 0) {
            RTE_LOG(ERR, VHOST_CONFIG, "Fail to find DMA %s.\n", ptrs[1]);
            ret = -1;
            goto out;
        }

        /* DMA device is already configured, so skip */
        if (is_dma_configured(dev_id))
            goto done;

        if (rte_dma_info_get(dev_id, &info) != 0) {
            RTE_LOG(ERR, VHOST_CONFIG, "Error with rte_dma_info_get()\n");
            ret = -1;
            goto out;
        }

        if (info.max_vchans < 1) {
            RTE_LOG(ERR, VHOST_CONFIG, "No channels available on device %d\n", dev_id);
            ret = -1;
            goto out;
        }

        if (rte_dma_configure(dev_id, &dev_config) != 0) {
            RTE_LOG(ERR, VHOST_CONFIG, "Fail to configure DMA %d.\n", dev_id);
            ret = -1;
            goto out;
        }

        /* Check the max desc supported by DMA device */
        rte_dma_info_get(dev_id, &info);
        if (info.nb_vchans != 1) {
            RTE_LOG(ERR, VHOST_CONFIG, "No configured queues reported by DMA %d.\n",
                    dev_id);
            ret = -1;
            goto out;
        }

        qconf.nb_desc = RTE_MIN(DMA_RING_SIZE, info.max_desc);

        if (rte_dma_vchan_setup(dev_id, 0, &qconf) != 0) {
            RTE_LOG(ERR, VHOST_CONFIG, "Fail to set up DMA %d.\n", dev_id);
            ret = -1;
            goto out;
        }

        if (rte_dma_start(dev_id) != 0) {
            RTE_LOG(ERR, VHOST_CONFIG, "Fail to start DMA %u.\n", dev_id);
            ret = -1;
            goto out;
        }

        dmas_id[dma_count++] = dev_id;

done:
        (dma_info + vid)->dmas[VIRTIO_RXQ].dev_id = dev_id;
        i++;
    }
out:
    free(input);
    return ret;
}

/*
 * Builds up the correct configuration for VMDQ VLAN pool map
 * according to the pool & queue limits.
 */
static inline int
get_eth_conf(struct rte_eth_conf *eth_conf, uint32_t num_devices)
{
    struct rte_eth_vmdq_rx_conf conf;
    struct rte_eth_vmdq_rx_conf *def_conf =
        &vmdq_conf_default.rx_adv_conf.vmdq_rx_conf;
    unsigned i;

    memset(&conf, 0, sizeof(conf));
    conf.nb_queue_pools = (enum rte_eth_nb_pools)num_devices;
    conf.nb_pool_maps = num_devices;
    conf.enable_loop_back = def_conf->enable_loop_back;
    conf.rx_mode = def_conf->rx_mode;

    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);
    }

    (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;
}

/*
 * Initialises a given port using global settings and with the rx buffers
 * coming from the mbuf_pool passed as parameter
 */
static inline int
port_init(uint16_t port)
{
    struct rte_eth_dev_info dev_info;
    struct rte_eth_conf port_conf;
    struct rte_eth_rxconf *rxconf;
    struct rte_eth_txconf *txconf;
    int16_t rx_rings, tx_rings;
    uint16_t rx_ring_size, tx_ring_size;
    int retval;
    uint16_t q;

    /* The max pool number from dev_info will be used to validate the pool number specified in cmd line */
    retval = rte_eth_dev_info_get(port, &dev_info);
    if (retval != 0) {
        RTE_LOG(ERR, VHOST_PORT,
            "Error during getting device (port %u) info: %s\n",
            port, strerror(-retval));

        return retval;
    }

    rxconf = &dev_info.default_rxconf;
    txconf = &dev_info.default_txconf;
    rxconf->rx_drop_en = 1;

    /*configure the number of supported virtio devices based on VMDQ limits */
    num_devices = dev_info.max_vmdq_pools;

    rx_ring_size = RTE_TEST_RX_DESC_DEFAULT;
    tx_ring_size = RTE_TEST_TX_DESC_DEFAULT;

    tx_rings = (uint16_t)rte_lcore_count();

    if (mergeable) {
        if (dev_info.max_mtu != UINT16_MAX && dev_info.max_rx_pktlen > dev_info.max_mtu)
            vmdq_conf_default.rxmode.mtu = dev_info.max_mtu;
        else
            vmdq_conf_default.rxmode.mtu = MAX_MTU;
    }

    /* Get port configuration. */
    retval = get_eth_conf(&port_conf, num_devices);
    if (retval < 0)
        return retval;
    /* NIC queues are divided into pf queues and vmdq queues.  */
    num_pf_queues = dev_info.max_rx_queues - dev_info.vmdq_queue_num;
    queues_per_pool = dev_info.vmdq_queue_num / dev_info.max_vmdq_pools;
    num_vmdq_queues = num_devices * queues_per_pool;
    num_queues = num_pf_queues + num_vmdq_queues;
    vmdq_queue_base = dev_info.vmdq_queue_base;
    vmdq_pool_base  = dev_info.vmdq_pool_base;
    printf("pf queue num: %u, configured vmdq pool num: %u, each vmdq pool has %u queues\n",
        num_pf_queues, num_devices, queues_per_pool);

    if (!rte_eth_dev_is_valid_port(port))
        return -1;

    rx_rings = (uint16_t)dev_info.max_rx_queues;
    if (dev_info.tx_offload_capa & RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE)
        port_conf.txmode.offloads |=
            RTE_ETH_TX_OFFLOAD_MBUF_FAST_FREE;
    /* Configure ethernet device. */
    retval = rte_eth_dev_configure(port, rx_rings, tx_rings, &port_conf);
    if (retval != 0) {
        RTE_LOG(ERR, VHOST_PORT, "Failed to configure port %u: %s.\n",
            port, strerror(-retval));
        return retval;
    }

    retval = rte_eth_dev_adjust_nb_rx_tx_desc(port, &rx_ring_size,
        &tx_ring_size);
    if (retval != 0) {
        RTE_LOG(ERR, VHOST_PORT, "Failed to adjust number of descriptors "
            "for port %u: %s.\n", port, strerror(-retval));
        return retval;
    }
    if (rx_ring_size > RTE_TEST_RX_DESC_DEFAULT) {
        RTE_LOG(ERR, VHOST_PORT, "Mbuf pool has an insufficient size "
            "for Rx queues on port %u.\n", port);
        return -1;
    }

    /* Setup the queues. */
    rxconf->offloads = port_conf.rxmode.offloads;
    for (q = 0; q < rx_rings; q ++) {
        retval = rte_eth_rx_queue_setup(port, q, rx_ring_size,
                        rte_eth_dev_socket_id(port),
                        rxconf,
                        mbuf_pool);
        if (retval < 0) {
            RTE_LOG(ERR, VHOST_PORT,
                "Failed to setup rx queue %u of port %u: %s.\n",
                q, port, strerror(-retval));
            return retval;
        }
    }
    txconf->offloads = port_conf.txmode.offloads;
    for (q = 0; q < tx_rings; q ++) {
        retval = rte_eth_tx_queue_setup(port, q, tx_ring_size,
                        rte_eth_dev_socket_id(port),
                        txconf);
        if (retval < 0) {
            RTE_LOG(ERR, VHOST_PORT,
                "Failed to setup tx queue %u of port %u: %s.\n",
                q, port, strerror(-retval));
            return retval;
        }
    }

    /* Start the device. */
    retval  = rte_eth_dev_start(port);
    if (retval < 0) {
        RTE_LOG(ERR, VHOST_PORT, "Failed to start port %u: %s\n",
            port, strerror(-retval));
        return retval;
    }

    if (promiscuous) {
        retval = rte_eth_promiscuous_enable(port);
        if (retval != 0) {
            RTE_LOG(ERR, VHOST_PORT,
                "Failed to enable promiscuous mode on port %u: %s\n",
                port, rte_strerror(-retval));
            return retval;
        }
    }

    retval = rte_eth_macaddr_get(port, &vmdq_ports_eth_addr[port]);
    if (retval < 0) {
        RTE_LOG(ERR, VHOST_PORT,
            "Failed to get MAC address on port %u: %s\n",
            port, rte_strerror(-retval));
        return retval;
    }

    RTE_LOG(INFO, VHOST_PORT, "Max virtio devices supported: %u\n", num_devices);
    RTE_LOG(INFO, VHOST_PORT, "Port %u MAC: %02"PRIx8" %02"PRIx8" %02"PRIx8
        " %02"PRIx8" %02"PRIx8" %02"PRIx8"\n",
        port, RTE_ETHER_ADDR_BYTES(&vmdq_ports_eth_addr[port]));

    return 0;
}

/*
 * Set socket file path.
 */
static int
us_vhost_parse_socket_path(const char *q_arg)
{
    char *old;

    /* parse number string */
    if (strnlen(q_arg, PATH_MAX) == PATH_MAX)
        return -1;

    old = socket_files;
    socket_files = realloc(socket_files, PATH_MAX * (nb_sockets + 1));
    if (socket_files == NULL) {
        free(old);
        return -1;
    }

    strlcpy(socket_files + nb_sockets * PATH_MAX, q_arg, PATH_MAX);
    nb_sockets++;

    return 0;
}

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

    errno = 0;

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

    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;

    errno = 0;

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

    if (num > max_valid_value)
        return -1;

    return num;

}

/*
 * Display usage
 */
static void
us_vhost_usage(const char *prgname)
{
    RTE_LOG(INFO, VHOST_CONFIG, "%s [EAL options] -- -p PORTMASK\n"
    "       --vm2vm [0|1|2]\n"
    "       --rx_retry [0|1] --mergeable [0|1] --stats [0-N]\n"
    "       --socket-file <path>\n"
    "       --nb-devices ND\n"
    "       -p PORTMASK: Set mask for ports to be used by application\n"
    "       --vm2vm [0|1|2]: disable/software(default)/hardware vm2vm comms\n"
    "       --rx-retry [0|1]: disable/enable(default) retries on Rx. Enable retry if destination 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"
    "       --mergeable [0|1]: disable(default)/enable RX mergeable buffers\n"
    "       --stats [0-N]: 0: Disable stats, N: Time in seconds to print stats\n"
    "       --socket-file: The path of the socket file.\n"
    "       --tx-csum [0|1] disable/enable TX checksum offload.\n"
    "       --tso [0|1] disable/enable TCP segment offload.\n"
    "       --client register a vhost-user socket as client mode.\n"
    "       --dmas register dma channel for specific vhost device.\n"
    "       --total-num-mbufs [0-N] set the number of mbufs to be allocated in mbuf pools, the default value is 147456.\n",
           prgname);
}

enum {
#define OPT_VM2VM               "vm2vm"
    OPT_VM2VM_NUM = 256,
#define OPT_RX_RETRY            "rx-retry"
    OPT_RX_RETRY_NUM,
#define OPT_RX_RETRY_DELAY      "rx-retry-delay"
    OPT_RX_RETRY_DELAY_NUM,
#define OPT_RX_RETRY_NUMB       "rx-retry-num"
    OPT_RX_RETRY_NUMB_NUM,
#define OPT_MERGEABLE           "mergeable"
    OPT_MERGEABLE_NUM,
#define OPT_STATS               "stats"
    OPT_STATS_NUM,
#define OPT_SOCKET_FILE         "socket-file"
    OPT_SOCKET_FILE_NUM,
#define OPT_TX_CSUM             "tx-csum"
    OPT_TX_CSUM_NUM,
#define OPT_TSO                 "tso"
    OPT_TSO_NUM,
#define OPT_CLIENT              "client"
    OPT_CLIENT_NUM,
#define OPT_BUILTIN_NET_DRIVER  "builtin-net-driver"
    OPT_BUILTIN_NET_DRIVER_NUM,
#define OPT_DMAS                "dmas"
    OPT_DMAS_NUM,
#define OPT_NUM_MBUFS           "total-num-mbufs"
    OPT_NUM_MBUFS_NUM,
};

/*
 * Parse the arguments given in the command line of the application.
 */
static int
us_vhost_parse_args(int argc, char **argv)
{
    int opt, ret;
    int option_index;
    unsigned i;
    const char *prgname = argv[0];
    static struct option long_option[] = {
        {OPT_VM2VM, required_argument,
                NULL, OPT_VM2VM_NUM},
        {OPT_RX_RETRY, required_argument,
                NULL, OPT_RX_RETRY_NUM},
        {OPT_RX_RETRY_DELAY, required_argument,
                NULL, OPT_RX_RETRY_DELAY_NUM},
        {OPT_RX_RETRY_NUMB, required_argument,
                NULL, OPT_RX_RETRY_NUMB_NUM},
        {OPT_MERGEABLE, required_argument,
                NULL, OPT_MERGEABLE_NUM},
        {OPT_STATS, required_argument,
                NULL, OPT_STATS_NUM},
        {OPT_SOCKET_FILE, required_argument,
                NULL, OPT_SOCKET_FILE_NUM},
        {OPT_TX_CSUM, required_argument,
                NULL, OPT_TX_CSUM_NUM},
        {OPT_TSO, required_argument,
                NULL, OPT_TSO_NUM},
        {OPT_CLIENT, no_argument,
                NULL, OPT_CLIENT_NUM},
        {OPT_BUILTIN_NET_DRIVER, no_argument,
                NULL, OPT_BUILTIN_NET_DRIVER_NUM},
        {OPT_DMAS, required_argument,
                NULL, OPT_DMAS_NUM},
        {OPT_NUM_MBUFS, required_argument,
                NULL, OPT_NUM_MBUFS_NUM},
        {NULL, 0, 0, 0},
    };

    /* Parse command line */
    while ((opt = getopt_long(argc, argv, "p: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");
                us_vhost_usage(prgname);
                return -1;
            }
            break;

        case 'P':
            promiscuous = 1;
            vmdq_conf_default.rx_adv_conf.vmdq_rx_conf.rx_mode =
                RTE_ETH_VMDQ_ACCEPT_BROADCAST |
                RTE_ETH_VMDQ_ACCEPT_MULTICAST;
            break;

        case OPT_VM2VM_NUM:
            ret = parse_num_opt(optarg, (VM2VM_LAST - 1));
            if (ret == -1) {
                RTE_LOG(INFO, VHOST_CONFIG,
                    "Invalid argument for "
                    "vm2vm [0|1|2]\n");
                us_vhost_usage(prgname);
                return -1;
            }
            vm2vm_mode = (vm2vm_type)ret;
            break;

        case OPT_RX_RETRY_NUM:
            ret = parse_num_opt(optarg, 1);
            if (ret == -1) {
                RTE_LOG(INFO, VHOST_CONFIG, "Invalid argument for rx-retry [0|1]\n");
                us_vhost_usage(prgname);
                return -1;
            }
            enable_retry = ret;
            break;

        case OPT_TX_CSUM_NUM:
            ret = parse_num_opt(optarg, 1);
            if (ret == -1) {
                RTE_LOG(INFO, VHOST_CONFIG, "Invalid argument for tx-csum [0|1]\n");
                us_vhost_usage(prgname);
                return -1;
            }
            enable_tx_csum = ret;
            break;

        case OPT_TSO_NUM:
            ret = parse_num_opt(optarg, 1);
            if (ret == -1) {
                RTE_LOG(INFO, VHOST_CONFIG, "Invalid argument for tso [0|1]\n");
                us_vhost_usage(prgname);
                return -1;
            }
            enable_tso = ret;
            break;

        case OPT_RX_RETRY_DELAY_NUM:
            ret = parse_num_opt(optarg, INT32_MAX);
            if (ret == -1) {
                RTE_LOG(INFO, VHOST_CONFIG, "Invalid argument for rx-retry-delay [0-N]\n");
                us_vhost_usage(prgname);
                return -1;
            }
            burst_rx_delay_time = ret;
            break;

        case OPT_RX_RETRY_NUMB_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");
                us_vhost_usage(prgname);
                return -1;
            }
            burst_rx_retry_num = ret;
            break;

        case OPT_MERGEABLE_NUM:
            ret = parse_num_opt(optarg, 1);
            if (ret == -1) {
                RTE_LOG(INFO, VHOST_CONFIG, "Invalid argument for mergeable [0|1]\n");
                us_vhost_usage(prgname);
                return -1;
            }
            mergeable = !!ret;
            break;

        case OPT_STATS_NUM:
            ret = parse_num_opt(optarg, INT32_MAX);
            if (ret == -1) {
                RTE_LOG(INFO, VHOST_CONFIG,
                    "Invalid argument for stats [0..N]\n");
                us_vhost_usage(prgname);
                return -1;
            }
            enable_stats = ret;
            break;

        /* Set socket file path. */
        case OPT_SOCKET_FILE_NUM:
            if (us_vhost_parse_socket_path(optarg) == -1) {
                RTE_LOG(INFO, VHOST_CONFIG,
                "Invalid argument for socket name (Max %d characters)\n",
                PATH_MAX);
                us_vhost_usage(prgname);
                return -1;
            }
            break;

        case OPT_DMAS_NUM:
            if (open_dma(optarg) == -1) {
                RTE_LOG(INFO, VHOST_CONFIG,
                    "Wrong DMA args\n");
                us_vhost_usage(prgname);
                return -1;
            }
            break;

        case OPT_NUM_MBUFS_NUM:
            ret = parse_num_opt(optarg, INT32_MAX);
            if (ret == -1) {
                RTE_LOG(INFO, VHOST_CONFIG,
                    "Invalid argument for total-num-mbufs [0..N]\n");
                us_vhost_usage(prgname);
                return -1;
            }

            if (total_num_mbufs < ret)
                total_num_mbufs = ret;
            break;

        case OPT_CLIENT_NUM:
            client_mode = 1;
            break;

        case OPT_BUILTIN_NET_DRIVER_NUM:
            builtin_net_driver = 1;
            break;

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

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

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

    return 0;
}

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

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

    for (portid = 0; portid < num_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_num_ports--;
        }
    }
    return valid_num_ports;
}

static __rte_always_inline struct vhost_dev *
find_vhost_dev(struct rte_ether_addr *mac)
{
    struct vhost_dev *vdev;

    TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
        if (vdev->ready == DEVICE_RX &&
            rte_is_same_ether_addr(mac, &vdev->mac_address))
            return vdev;
    }

    return NULL;
}

/*
 * This function learns the MAC address of the device and registers this along with a
 * vlan tag to a VMDQ.
 */
static int
link_vmdq(struct vhost_dev *vdev, struct rte_mbuf *m)
{
    struct rte_ether_hdr *pkt_hdr;
    int i, ret;

    /* Learn MAC address of guest device from packet */
    pkt_hdr = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);

    if (find_vhost_dev(&pkt_hdr->src_addr)) {
        RTE_LOG(ERR, VHOST_DATA,
            "(%d) device is using a registered MAC!\n",
            vdev->vid);
        return -1;
    }

    for (i = 0; i < RTE_ETHER_ADDR_LEN; i++)
        vdev->mac_address.addr_bytes[i] =
            pkt_hdr->src_addr.addr_bytes[i];

    /* vlan_tag currently uses the device_id. */
    vdev->vlan_tag = vlan_tags[vdev->vid];

    /* Print out VMDQ registration info. */
    RTE_LOG(INFO, VHOST_DATA,
        "(%d) mac " RTE_ETHER_ADDR_PRT_FMT " and vlan %d registered\n",
        vdev->vid, RTE_ETHER_ADDR_BYTES(&vdev->mac_address),
        vdev->vlan_tag);

    /* Register the MAC address. */
    ret = rte_eth_dev_mac_addr_add(ports[0], &vdev->mac_address,
                (uint32_t)vdev->vid + vmdq_pool_base);
    if (ret)
        RTE_LOG(ERR, VHOST_DATA,
            "(%d) failed to add device MAC address to VMDQ\n",
            vdev->vid);

    rte_eth_dev_set_vlan_strip_on_queue(ports[0], vdev->vmdq_rx_q, 1);

    /* Set device as ready for RX. */
    vdev->ready = DEVICE_RX;

    return 0;
}

/*
 * Removes MAC address and vlan tag from VMDQ. Ensures that nothing is adding buffers to the RX
 * queue before disabling RX on the device.
 */
static inline void
unlink_vmdq(struct vhost_dev *vdev)
{
    unsigned i = 0;
    unsigned rx_count;
    struct rte_mbuf *pkts_burst[MAX_PKT_BURST];

    if (vdev->ready == DEVICE_RX) {
        /*clear MAC and VLAN settings*/
        rte_eth_dev_mac_addr_remove(ports[0], &vdev->mac_address);
        for (i = 0; i < 6; i++)
            vdev->mac_address.addr_bytes[i] = 0;

        vdev->vlan_tag = 0;

        /*Clear out the receive buffers*/
        rx_count = rte_eth_rx_burst(ports[0],
                    (uint16_t)vdev->vmdq_rx_q, pkts_burst, MAX_PKT_BURST);

        while (rx_count) {
            for (i = 0; i < rx_count; i++)
                rte_pktmbuf_free(pkts_burst[i]);

            rx_count = rte_eth_rx_burst(ports[0],
                    (uint16_t)vdev->vmdq_rx_q, pkts_burst, MAX_PKT_BURST);
        }

        vdev->ready = DEVICE_MAC_LEARNING;
    }
}

static inline void
free_pkts(struct rte_mbuf **pkts, uint16_t n)
{
    while (n--)
        rte_pktmbuf_free(pkts[n]);
}

static __rte_always_inline void
complete_async_pkts(struct vhost_dev *vdev)
{
    struct rte_mbuf *p_cpl[MAX_PKT_BURST];
    uint16_t complete_count;
    int16_t dma_id = dma_bind[vdev->vid].dmas[VIRTIO_RXQ].dev_id;

    complete_count = rte_vhost_poll_enqueue_completed(vdev->vid,
                    VIRTIO_RXQ, p_cpl, MAX_PKT_BURST, dma_id, 0);
    if (complete_count) {
        free_pkts(p_cpl, complete_count);
        __atomic_sub_fetch(&vdev->pkts_inflight, complete_count, __ATOMIC_SEQ_CST);
    }

}

static __rte_always_inline void
sync_virtio_xmit(struct vhost_dev *dst_vdev, struct vhost_dev *src_vdev,
        struct rte_mbuf *m)
{
    uint16_t ret;

    if (builtin_net_driver) {
        ret = vs_enqueue_pkts(dst_vdev, VIRTIO_RXQ, &m, 1);
    } else {
        ret = rte_vhost_enqueue_burst(dst_vdev->vid, VIRTIO_RXQ, &m, 1);
    }

    if (enable_stats) {
        __atomic_add_fetch(&dst_vdev->stats.rx_total_atomic, 1,
                __ATOMIC_SEQ_CST);
        __atomic_add_fetch(&dst_vdev->stats.rx_atomic, ret,
                __ATOMIC_SEQ_CST);
        src_vdev->stats.tx_total++;
        src_vdev->stats.tx += ret;
    }
}

static __rte_always_inline void
drain_vhost(struct vhost_dev *vdev)
{
    uint16_t ret;
    uint32_t buff_idx = rte_lcore_id() * RTE_MAX_VHOST_DEVICE + vdev->vid;
    uint16_t nr_xmit = vhost_txbuff[buff_idx]->len;
    struct rte_mbuf **m = vhost_txbuff[buff_idx]->m_table;

    if (builtin_net_driver) {
        ret = vs_enqueue_pkts(vdev, VIRTIO_RXQ, m, nr_xmit);
    } else if (dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled) {
        uint16_t enqueue_fail = 0;
        int16_t dma_id = dma_bind[vdev->vid].dmas[VIRTIO_RXQ].dev_id;

        complete_async_pkts(vdev);
        ret = rte_vhost_submit_enqueue_burst(vdev->vid, VIRTIO_RXQ, m, nr_xmit, dma_id, 0);
        __atomic_add_fetch(&vdev->pkts_inflight, ret, __ATOMIC_SEQ_CST);

        enqueue_fail = nr_xmit - ret;
        if (enqueue_fail)
            free_pkts(&m[ret], nr_xmit - ret);
    } else {
        ret = rte_vhost_enqueue_burst(vdev->vid, VIRTIO_RXQ,
                        m, nr_xmit);
    }

    if (enable_stats) {
        __atomic_add_fetch(&vdev->stats.rx_total_atomic, nr_xmit,
                __ATOMIC_SEQ_CST);
        __atomic_add_fetch(&vdev->stats.rx_atomic, ret,
                __ATOMIC_SEQ_CST);
    }

    if (!dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled)
        free_pkts(m, nr_xmit);
}

static __rte_always_inline void
drain_vhost_table(void)
{
    uint16_t lcore_id = rte_lcore_id();
    struct vhost_bufftable *vhost_txq;
    struct vhost_dev *vdev;
    uint64_t cur_tsc;

    TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
        if (unlikely(vdev->remove == 1))
            continue;

        vhost_txq = vhost_txbuff[lcore_id * RTE_MAX_VHOST_DEVICE + vdev->vid];

        cur_tsc = rte_rdtsc();
        if (unlikely(cur_tsc - vhost_txq->pre_tsc
                > MBUF_TABLE_DRAIN_TSC)) {
            RTE_LOG_DP(DEBUG, VHOST_DATA,
                "Vhost TX queue drained after timeout with burst size %u\n",
                vhost_txq->len);
            drain_vhost(vdev);
            vhost_txq->len = 0;
            vhost_txq->pre_tsc = cur_tsc;
        }
    }
}

/*
 * Check if the packet destination MAC address is for a local device. If so then put
 * the packet on that devices RX queue. If not then return.
 */
static __rte_always_inline int
virtio_tx_local(struct vhost_dev *vdev, struct rte_mbuf *m)
{
    struct rte_ether_hdr *pkt_hdr;
    struct vhost_dev *dst_vdev;
    struct vhost_bufftable *vhost_txq;
    uint16_t lcore_id = rte_lcore_id();
    pkt_hdr = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);

    dst_vdev = find_vhost_dev(&pkt_hdr->dst_addr);
    if (!dst_vdev)
        return -1;

    if (vdev->vid == dst_vdev->vid) {
        RTE_LOG_DP(DEBUG, VHOST_DATA,
            "(%d) TX: src and dst MAC is same. Dropping packet.\n",
            vdev->vid);
        return 0;
    }

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

    if (unlikely(dst_vdev->remove)) {
        RTE_LOG_DP(DEBUG, VHOST_DATA,
            "(%d) device is marked for removal\n", dst_vdev->vid);
        return 0;
    }

    vhost_txq = vhost_txbuff[lcore_id * RTE_MAX_VHOST_DEVICE + dst_vdev->vid];
    vhost_txq->m_table[vhost_txq->len++] = m;

    if (enable_stats) {
        vdev->stats.tx_total++;
        vdev->stats.tx++;
    }

    if (unlikely(vhost_txq->len == MAX_PKT_BURST)) {
        drain_vhost(dst_vdev);
        vhost_txq->len = 0;
        vhost_txq->pre_tsc = rte_rdtsc();
    }
    return 0;
}

/*
 * Check if the destination MAC of a packet is one local VM,
 * and get its vlan tag, and offset if it is.
 */
static __rte_always_inline int
find_local_dest(struct vhost_dev *vdev, struct rte_mbuf *m,
    uint32_t *offset, uint16_t *vlan_tag)
{
    struct vhost_dev *dst_vdev;
    struct rte_ether_hdr *pkt_hdr =
        rte_pktmbuf_mtod(m, struct rte_ether_hdr *);

    dst_vdev = find_vhost_dev(&pkt_hdr->dst_addr);
    if (!dst_vdev)
        return 0;

    if (vdev->vid == dst_vdev->vid) {
        RTE_LOG_DP(DEBUG, VHOST_DATA,
            "(%d) TX: src and dst MAC is same. Dropping packet.\n",
            vdev->vid);
        return -1;
    }

    /*
     * HW vlan strip will reduce the packet length
     * by minus length of vlan tag, so need restore
     * the packet length by plus it.
     */
    *offset  = RTE_VLAN_HLEN;
    *vlan_tag = vlan_tags[vdev->vid];

    RTE_LOG_DP(DEBUG, VHOST_DATA,
        "(%d) TX: pkt to local VM device id: (%d), vlan tag: %u.\n",
        vdev->vid, dst_vdev->vid, *vlan_tag);

    return 0;
}

static void virtio_tx_offload(struct rte_mbuf *m)
{
    struct rte_net_hdr_lens hdr_lens;
    struct rte_ipv4_hdr *ipv4_hdr;
    struct rte_tcp_hdr *tcp_hdr;
    uint32_t ptype;
    void *l3_hdr;

    ptype = rte_net_get_ptype(m, &hdr_lens, RTE_PTYPE_ALL_MASK);
    m->l2_len = hdr_lens.l2_len;
    m->l3_len = hdr_lens.l3_len;
    m->l4_len = hdr_lens.l4_len;

    l3_hdr = rte_pktmbuf_mtod_offset(m, void *, m->l2_len);
    tcp_hdr = rte_pktmbuf_mtod_offset(m, struct rte_tcp_hdr *,
        m->l2_len + m->l3_len);

    m->ol_flags |= RTE_MBUF_F_TX_TCP_SEG;
    if ((ptype & RTE_PTYPE_L3_MASK) == RTE_PTYPE_L3_IPV4) {
        m->ol_flags |= RTE_MBUF_F_TX_IPV4;
        m->ol_flags |= RTE_MBUF_F_TX_IP_CKSUM;
        ipv4_hdr = l3_hdr;
        ipv4_hdr->hdr_checksum = 0;
        tcp_hdr->cksum = rte_ipv4_phdr_cksum(l3_hdr, m->ol_flags);
    } else { /* assume ethertype == RTE_ETHER_TYPE_IPV6 */
        m->ol_flags |= RTE_MBUF_F_TX_IPV6;
        tcp_hdr->cksum = rte_ipv6_phdr_cksum(l3_hdr, m->ol_flags);
    }
}

static __rte_always_inline void
do_drain_mbuf_table(struct mbuf_table *tx_q)
{
    uint16_t count;

    count = rte_eth_tx_burst(ports[0], tx_q->txq_id,
                 tx_q->m_table, tx_q->len);
    if (unlikely(count < tx_q->len))
        free_pkts(&tx_q->m_table[count], tx_q->len - count);

    tx_q->len = 0;
}

/*
 * 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, uint16_t vlan_tag)
{
    struct mbuf_table *tx_q;
    unsigned offset = 0;
    const uint16_t lcore_id = rte_lcore_id();
    struct rte_ether_hdr *nh;


    nh = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
    if (unlikely(rte_is_broadcast_ether_addr(&nh->dst_addr))) {
        struct vhost_dev *vdev2;

        TAILQ_FOREACH(vdev2, &vhost_dev_list, global_vdev_entry) {
            if (vdev2 != vdev)
                sync_virtio_xmit(vdev2, vdev, m);
        }
        goto queue2nic;
    }

    /*check if destination is local VM*/
    if ((vm2vm_mode == VM2VM_SOFTWARE) && (virtio_tx_local(vdev, m) == 0))
        return;

    if (unlikely(vm2vm_mode == VM2VM_HARDWARE)) {
        if (unlikely(find_local_dest(vdev, m, &offset,
                         &vlan_tag) != 0)) {
            rte_pktmbuf_free(m);
            return;
        }
    }

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

queue2nic:

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

    nh = rte_pktmbuf_mtod(m, struct rte_ether_hdr *);
    if (unlikely(nh->ether_type == rte_cpu_to_be_16(RTE_ETHER_TYPE_VLAN))) {
        /* Guest has inserted the vlan tag. */
        struct rte_vlan_hdr *vh = (struct rte_vlan_hdr *) (nh + 1);
        uint16_t vlan_tag_be = rte_cpu_to_be_16(vlan_tag);
        if ((vm2vm_mode == VM2VM_HARDWARE) &&
            (vh->vlan_tci != vlan_tag_be))
            vh->vlan_tci = vlan_tag_be;
    } else {
        m->ol_flags |= RTE_MBUF_F_TX_VLAN;

        /*
         * Find the right seg to adjust the data len when offset is
         * bigger than tail room size.
         */
        if (unlikely(vm2vm_mode == VM2VM_HARDWARE)) {
            if (likely(offset <= rte_pktmbuf_tailroom(m)))
                m->data_len += offset;
            else {
                struct rte_mbuf *seg = m;

                while ((seg->next != NULL) &&
                    (offset > rte_pktmbuf_tailroom(seg)))
                    seg = seg->next;

                seg->data_len += offset;
            }
            m->pkt_len += offset;
        }

        m->vlan_tci = vlan_tag;
    }

    if (m->ol_flags & RTE_MBUF_F_RX_LRO)
        virtio_tx_offload(m);

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

    if (unlikely(tx_q->len == MAX_PKT_BURST))
        do_drain_mbuf_table(tx_q);
}


static __rte_always_inline void
drain_mbuf_table(struct mbuf_table *tx_q)
{
    static uint64_t prev_tsc;
    uint64_t cur_tsc;

    if (tx_q->len == 0)
        return;

    cur_tsc = rte_rdtsc();
    if (unlikely(cur_tsc - prev_tsc > MBUF_TABLE_DRAIN_TSC)) {
        prev_tsc = cur_tsc;

        RTE_LOG_DP(DEBUG, VHOST_DATA,
            "TX queue drained after timeout with burst size %u\n",
            tx_q->len);
        do_drain_mbuf_table(tx_q);
    }
}

static __rte_always_inline void
drain_eth_rx(struct vhost_dev *vdev)
{
    uint16_t rx_count, enqueue_count;
    struct rte_mbuf *pkts[MAX_PKT_BURST];

    rx_count = rte_eth_rx_burst(ports[0], vdev->vmdq_rx_q,
                    pkts, MAX_PKT_BURST);

    if (!rx_count)
        return;

    /*
     * When "enable_retry" is set, here we wait and retry when there
     * is no enough free slots in the queue to hold @rx_count packets,
     * to diminish packet loss.
     */
    if (enable_retry &&
        unlikely(rx_count > rte_vhost_avail_entries(vdev->vid,
            VIRTIO_RXQ))) {
        uint32_t retry;

        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;
        }
    }

    if (builtin_net_driver) {
        enqueue_count = vs_enqueue_pkts(vdev, VIRTIO_RXQ,
                        pkts, rx_count);
    } else if (dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled) {
        uint16_t enqueue_fail = 0;
        int16_t dma_id = dma_bind[vdev->vid].dmas[VIRTIO_RXQ].dev_id;

        complete_async_pkts(vdev);
        enqueue_count = rte_vhost_submit_enqueue_burst(vdev->vid,
                    VIRTIO_RXQ, pkts, rx_count, dma_id, 0);
        __atomic_add_fetch(&vdev->pkts_inflight, enqueue_count, __ATOMIC_SEQ_CST);

        enqueue_fail = rx_count - enqueue_count;
        if (enqueue_fail)
            free_pkts(&pkts[enqueue_count], enqueue_fail);

    } else {
        enqueue_count = rte_vhost_enqueue_burst(vdev->vid, VIRTIO_RXQ,
                        pkts, rx_count);
    }

    if (enable_stats) {
        __atomic_add_fetch(&vdev->stats.rx_total_atomic, rx_count,
                __ATOMIC_SEQ_CST);
        __atomic_add_fetch(&vdev->stats.rx_atomic, enqueue_count,
                __ATOMIC_SEQ_CST);
    }

    if (!dma_bind[vdev->vid].dmas[VIRTIO_RXQ].async_enabled)
        free_pkts(pkts, rx_count);
}

static __rte_always_inline void
drain_virtio_tx(struct vhost_dev *vdev)
{
    struct rte_mbuf *pkts[MAX_PKT_BURST];
    uint16_t count;
    uint16_t i;

    if (builtin_net_driver) {
        count = vs_dequeue_pkts(vdev, VIRTIO_TXQ, mbuf_pool,
                    pkts, MAX_PKT_BURST);
    } else {
        count = rte_vhost_dequeue_burst(vdev->vid, VIRTIO_TXQ,
                    mbuf_pool, pkts, MAX_PKT_BURST);
    }

    /* setup VMDq for the first packet */
    if (unlikely(vdev->ready == DEVICE_MAC_LEARNING) && count) {
        if (vdev->remove || link_vmdq(vdev, pkts[0]) == -1)
            free_pkts(pkts, count);
    }

    for (i = 0; i < count; ++i)
        virtio_tx_route(vdev, pkts[i], vlan_tags[vdev->vid]);
}

/*
 * Main function of vhost-switch. It basically does:
 *
 * for each vhost device {
 *    - drain_eth_rx()
 *
 *      Which drains the host eth Rx queue linked to the vhost device,
 *      and deliver all of them to guest virito Rx ring associated with
 *      this vhost device.
 *
 *    - drain_virtio_tx()
 *
 *      Which drains the guest virtio Tx queue and deliver all of them
 *      to the target, which could be another vhost device, or the
 *      physical eth dev. The route is done in function "virtio_tx_route".
 * }
 */
static int
switch_worker(void *arg __rte_unused)
{
    unsigned i;
    unsigned lcore_id = rte_lcore_id();
    struct vhost_dev *vdev;
    struct mbuf_table *tx_q;

    RTE_LOG(INFO, VHOST_DATA, "Processing on Core %u started\n", lcore_id);

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

    while(1) {
        drain_mbuf_table(tx_q);
        drain_vhost_table();
        /*
         * Inform the configuration core that we have exited the
         * linked list and that no devices are in use if requested.
         */
        if (lcore_info[lcore_id].dev_removal_flag == REQUEST_DEV_REMOVAL)
            lcore_info[lcore_id].dev_removal_flag = ACK_DEV_REMOVAL;

        /*
         * Process vhost devices
         */
        TAILQ_FOREACH(vdev, &lcore_info[lcore_id].vdev_list,
                  lcore_vdev_entry) {
            if (unlikely(vdev->remove)) {
                unlink_vmdq(vdev);
                vdev->ready = DEVICE_SAFE_REMOVE;
                continue;
            }

            if (likely(vdev->ready == DEVICE_RX))
                drain_eth_rx(vdev);

            if (likely(!vdev->remove))
                drain_virtio_tx(vdev);
        }
    }

    return 0;
}

/*
 * Remove a device from the specific data core linked list and from the
 * main linked list. Synchronization  occurs through the use of the
 * lcore dev_removal_flag. Device is made volatile here to avoid re-ordering
 * of dev->remove=1 which can cause an infinite loop in the rte_pause loop.
 */
static void
destroy_device(int vid)
{
    struct vhost_dev *vdev = NULL;
    int lcore;
    uint16_t i;

    TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
        if (vdev->vid == vid)
            break;
    }
    if (!vdev)
        return;
    /*set the remove flag. */
    vdev->remove = 1;
    while(vdev->ready != DEVICE_SAFE_REMOVE) {
        rte_pause();
    }

    for (i = 0; i < RTE_MAX_LCORE; i++)
        rte_free(vhost_txbuff[i * RTE_MAX_VHOST_DEVICE + vid]);

    if (builtin_net_driver)
        vs_vhost_net_remove(vdev);

    TAILQ_REMOVE(&lcore_info[vdev->coreid].vdev_list, vdev,
             lcore_vdev_entry);
    TAILQ_REMOVE(&vhost_dev_list, vdev, global_vdev_entry);


    /* Set the dev_removal_flag on each lcore. */
    RTE_LCORE_FOREACH_WORKER(lcore)
        lcore_info[lcore].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_WORKER(lcore) {
        while (lcore_info[lcore].dev_removal_flag != ACK_DEV_REMOVAL)
            rte_pause();
    }

    lcore_info[vdev->coreid].device_num--;

    RTE_LOG(INFO, VHOST_DATA,
        "(%d) device has been removed from data core\n",
        vdev->vid);

    if (dma_bind[vid].dmas[VIRTIO_RXQ].async_enabled) {
        uint16_t n_pkt = 0;
        int16_t dma_id = dma_bind[vid].dmas[VIRTIO_RXQ].dev_id;
        struct rte_mbuf *m_cpl[vdev->pkts_inflight];

        while (vdev->pkts_inflight) {
            n_pkt = rte_vhost_clear_queue_thread_unsafe(vid, VIRTIO_RXQ,
                        m_cpl, vdev->pkts_inflight, dma_id, 0);
            free_pkts(m_cpl, n_pkt);
            __atomic_sub_fetch(&vdev->pkts_inflight, n_pkt, __ATOMIC_SEQ_CST);
        }

        rte_vhost_async_channel_unregister(vid, VIRTIO_RXQ);
        dma_bind[vid].dmas[VIRTIO_RXQ].async_enabled = false;
    }

    rte_free(vdev);
}

/*
 * A new device is added to a data core. First the device is added to the main linked list
 * and then allocated to a specific data core.
 */
static int
new_device(int vid)
{
    int lcore, core_add = 0;
    uint16_t i;
    uint32_t device_num_min = num_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;

    for (i = 0; i < RTE_MAX_LCORE; i++) {
        vhost_txbuff[i * RTE_MAX_VHOST_DEVICE + vid]
            = rte_zmalloc("vhost bufftable",
                sizeof(struct vhost_bufftable),
                RTE_CACHE_LINE_SIZE);

        if (vhost_txbuff[i * RTE_MAX_VHOST_DEVICE + vid] == NULL) {
            RTE_LOG(INFO, VHOST_DATA,
              "(%d) couldn't allocate memory for vhost TX\n", vid);
            return -1;
        }
    }

    if (builtin_net_driver)
        vs_vhost_net_setup(vdev);

    TAILQ_INSERT_TAIL(&vhost_dev_list, vdev, global_vdev_entry);
    vdev->vmdq_rx_q = vid * queues_per_pool + vmdq_queue_base;

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

    /* Find a suitable lcore to add the device. */
    RTE_LCORE_FOREACH_WORKER(lcore) {
        if (lcore_info[lcore].device_num < device_num_min) {
            device_num_min = lcore_info[lcore].device_num;
            core_add = lcore;
        }
    }
    vdev->coreid = core_add;

    TAILQ_INSERT_TAIL(&lcore_info[vdev->coreid].vdev_list, vdev,
              lcore_vdev_entry);
    lcore_info[vdev->coreid].device_num++;

    /* Disable notifications. */
    rte_vhost_enable_guest_notification(vid, VIRTIO_RXQ, 0);
    rte_vhost_enable_guest_notification(vid, VIRTIO_TXQ, 0);

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

    if (dma_bind[vid].dmas[VIRTIO_RXQ].dev_id != INVALID_DMA_ID) {
        int ret;

        ret = rte_vhost_async_channel_register(vid, VIRTIO_RXQ);
        if (ret == 0)
            dma_bind[vid].dmas[VIRTIO_RXQ].async_enabled = true;
        return ret;
    }

    return 0;
}

static int
vring_state_changed(int vid, uint16_t queue_id, int enable)
{
    struct vhost_dev *vdev = NULL;

    TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
        if (vdev->vid == vid)
            break;
    }
    if (!vdev)
        return -1;

    if (queue_id != VIRTIO_RXQ)
        return 0;

    if (dma_bind[vid].dmas[queue_id].async_enabled) {
        if (!enable) {
            uint16_t n_pkt = 0;
            int16_t dma_id = dma_bind[vid].dmas[VIRTIO_RXQ].dev_id;
            struct rte_mbuf *m_cpl[vdev->pkts_inflight];

            while (vdev->pkts_inflight) {
                n_pkt = rte_vhost_clear_queue_thread_unsafe(vid, queue_id,
                            m_cpl, vdev->pkts_inflight, dma_id, 0);
                free_pkts(m_cpl, n_pkt);
                __atomic_sub_fetch(&vdev->pkts_inflight, n_pkt, __ATOMIC_SEQ_CST);
            }
        }
    }

    return 0;
}

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

/*
 * 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 vhost_dev *vdev;
    uint64_t tx_dropped, rx_dropped;
    uint64_t tx, tx_total, rx, rx_total;
    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\n", clr, top_left);
        printf("Device statistics =================================\n");

        TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
            tx_total   = vdev->stats.tx_total;
            tx         = vdev->stats.tx;
            tx_dropped = tx_total - tx;

            rx_total = __atomic_load_n(&vdev->stats.rx_total_atomic,
                __ATOMIC_SEQ_CST);
            rx         = __atomic_load_n(&vdev->stats.rx_atomic,
                __ATOMIC_SEQ_CST);
            rx_dropped = rx_total - rx;

            printf("Statistics for device %d\n"
                "-----------------------\n"
                "TX total:              %" PRIu64 "\n"
                "TX dropped:            %" PRIu64 "\n"
                "TX successful:         %" PRIu64 "\n"
                "RX total:              %" PRIu64 "\n"
                "RX dropped:            %" PRIu64 "\n"
                "RX successful:         %" PRIu64 "\n",
                vdev->vid,
                tx_total, tx_dropped, tx,
                rx_total, rx_dropped, rx);
        }

        printf("===================================================\n");

        fflush(stdout);
    }

    return NULL;
}

static void
unregister_drivers(int socket_num)
{
    int i, ret;

    for (i = 0; i < socket_num; i++) {
        ret = rte_vhost_driver_unregister(socket_files + i * PATH_MAX);
        if (ret != 0)
            RTE_LOG(ERR, VHOST_CONFIG,
                "Fail to unregister vhost driver for %s.\n",
                socket_files + i * PATH_MAX);
    }
}

/* When we receive a INT signal, unregister vhost driver */
static void
sigint_handler(__rte_unused int signum)
{
    /* Unregister vhost driver. */
    unregister_drivers(nb_sockets);

    exit(0);
}

static void
reset_dma(void)
{
    int i;

    for (i = 0; i < RTE_MAX_VHOST_DEVICE; i++) {
        int j;

        for (j = 0; j < RTE_MAX_QUEUES_PER_PORT * 2; j++) {
            dma_bind[i].dmas[j].dev_id = INVALID_DMA_ID;
            dma_bind[i].dmas[j].async_enabled = false;
        }
    }

    for (i = 0; i < RTE_DMADEV_DEFAULT_MAX; i++)
        dmas_id[i] = INVALID_DMA_ID;
}

/*
 * Main function, does initialisation and calls the per-lcore functions.
 */
int
main(int argc, char *argv[])
{
    unsigned lcore_id, core_id = 0;
    unsigned nb_ports, valid_num_ports;
    int ret, i;
    uint16_t portid;
    static pthread_t tid;
    uint64_t flags = RTE_VHOST_USER_NET_COMPLIANT_OL_FLAGS;

    signal(SIGINT, sigint_handler);

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

    /* initialize dma structures */
    reset_dma();

    /* parse app arguments */
    ret = us_vhost_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++) {
        TAILQ_INIT(&lcore_info[lcore_id].vdev_list);

        if (rte_lcore_is_enabled(lcore_id))
            lcore_ids[core_id++] = lcore_id;
    }

    if (rte_lcore_count() > RTE_MAX_LCORE)
        rte_exit(EXIT_FAILURE,"Not enough cores\n");

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

    /*
     * Update the global var NUM_PORTS and global array PORTS
     * and get value of var VALID_NUM_PORTS according to system ports number
     */
    valid_num_ports = check_ports_num(nb_ports);

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

    /*
     * FIXME: here we are trying to allocate mbufs big enough for
     * @MAX_QUEUES, but the truth is we're never going to use that
     * many queues here. We probably should only do allocation for
     * those queues we are going to use.
     */
    mbuf_pool = rte_pktmbuf_pool_create("MBUF_POOL", total_num_mbufs,
                        MBUF_CACHE_SIZE, 0, MBUF_DATA_SIZE,
                        rte_socket_id());
    if (mbuf_pool == NULL)
        rte_exit(EXIT_FAILURE, "Cannot create mbuf pool\n");

    if (vm2vm_mode == VM2VM_HARDWARE) {
        /* Enable VT loop back to let L2 switch to do it. */
        vmdq_conf_default.rx_adv_conf.vmdq_rx_conf.enable_loop_back = 1;
        RTE_LOG(DEBUG, VHOST_CONFIG,
            "Enable loop back for L2 switch in vmdq.\n");
    }

    /* 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 (port_init(portid) != 0)
            rte_exit(EXIT_FAILURE,
                "Cannot initialize network ports\n");
    }

    /* 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_WORKER(lcore_id)
        rte_eal_remote_launch(switch_worker, NULL, lcore_id);

    if (client_mode)
        flags |= RTE_VHOST_USER_CLIENT;

    for (i = 0; i < dma_count; i++) {
        if (rte_vhost_async_dma_configure(dmas_id[i], 0) < 0) {
            RTE_LOG(ERR, VHOST_PORT, "Failed to configure DMA in vhost.\n");
            rte_exit(EXIT_FAILURE, "Cannot use given DMA device\n");
        }
    }

    /* Register vhost user driver to handle vhost messages. */
    for (i = 0; i < nb_sockets; i++) {
        char *file = socket_files + i * PATH_MAX;

        if (dma_count)
            flags = flags | RTE_VHOST_USER_ASYNC_COPY;

        ret = rte_vhost_driver_register(file, flags);
        if (ret != 0) {
            unregister_drivers(i);
            rte_exit(EXIT_FAILURE,
                "vhost driver register failure.\n");
        }

        if (builtin_net_driver)
            rte_vhost_driver_set_features(file, VIRTIO_NET_FEATURES);

        if (mergeable == 0) {
            rte_vhost_driver_disable_features(file,
                1ULL << VIRTIO_NET_F_MRG_RXBUF);
        }

        if (enable_tx_csum == 0) {
            rte_vhost_driver_disable_features(file,
                1ULL << VIRTIO_NET_F_CSUM);
        }

        if (enable_tso == 0) {
            rte_vhost_driver_disable_features(file,
                1ULL << VIRTIO_NET_F_HOST_TSO4);
            rte_vhost_driver_disable_features(file,
                1ULL << VIRTIO_NET_F_HOST_TSO6);
            rte_vhost_driver_disable_features(file,
                1ULL << VIRTIO_NET_F_GUEST_TSO4);
            rte_vhost_driver_disable_features(file,
                1ULL << VIRTIO_NET_F_GUEST_TSO6);
        }

        if (promiscuous) {
            rte_vhost_driver_enable_features(file,
                1ULL << VIRTIO_NET_F_CTRL_RX);
        }

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

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

    RTE_LCORE_FOREACH_WORKER(lcore_id)
        rte_eal_wait_lcore(lcore_id);

    /* clean up the EAL */
    rte_eal_cleanup();

    return 0;
}