text: /*
   * Copyright (c) 2015 Cisco and/or its affiliates.
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at:
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  #include <vnet/vnet.h>
  #include <vppinfra/vec.h>
  #include <vppinfra/format.h>
  #include <vlib/unix/cj.h>
  #include <assert.h>
  
  #include <vnet/ethernet/ethernet.h>
  #include <vnet/devices/dpdk/dpdk.h>
  
  #include "dpdk_priv.h"
  #include <vppinfra/error.h>
  
  #define foreach_dpdk_tx_func_error			\
    _(BAD_RETVAL, "DPDK tx function returned an error")	\
    _(RING_FULL, "Tx packet drops (ring full)")	        \
    _(PKT_DROP, "Tx packet drops (dpdk tx failure)")	\
    _(REPL_FAIL, "Tx packet drops (replication failure)")
  
  typedef enum {
  #define _(f,s) DPDK_TX_FUNC_ERROR_##f,
    foreach_dpdk_tx_func_error
  #undef _
    DPDK_TX_FUNC_N_ERROR,
  } dpdk_tx_func_error_t;
  
  static char * dpdk_tx_func_error_strings[] = {
  #define _(n,s) s,
      foreach_dpdk_tx_func_error
  #undef _
  };
  
  clib_error_t *
  dpdk_set_mac_address (vnet_hw_interface_t * hi, char * address)
  {
     int error;
     dpdk_main_t * dm = &dpdk_main;
     dpdk_device_t * xd = vec_elt_at_index (dm->devices, hi->dev_instance);
  
     error=rte_eth_dev_default_mac_addr_set(xd->device_index,
                                            (struct ether_addr *) address);
  
     if (error) {
       return clib_error_return (0, "mac address set failed: %d", error);
     } else {
       return NULL;
    }
  }
  
  clib_error_t *
  dpdk_set_mc_filter (vnet_hw_interface_t * hi,
                      struct ether_addr mc_addr_vec[], int naddr)
  {
    int error;
    dpdk_main_t * dm = &dpdk_main;
    dpdk_device_t * xd = vec_elt_at_index (dm->devices, hi->dev_instance);
  
    error=rte_eth_dev_set_mc_addr_list(xd->device_index, mc_addr_vec, naddr);
  
    if (error) {
      return clib_error_return (0, "mc addr list failed: %d", error);
    } else {
      return NULL;
    }
  }
  
  struct rte_mbuf * dpdk_replicate_packet_mb (vlib_buffer_t * b)
  {
    vlib_main_t * vm = vlib_get_main();
    vlib_buffer_main_t * bm = vm->buffer_main;
    struct rte_mbuf * first_mb = 0, * new_mb, * pkt_mb, ** prev_mb_next = 0;
    u8 nb_segs, nb_segs_left;
    u32 copy_bytes;
    unsigned socket_id = rte_socket_id();
  
    ASSERT (bm->pktmbuf_pools[socket_id]);
    pkt_mb = rte_mbuf_from_vlib_buffer(b);
    nb_segs = pkt_mb->nb_segs;
    for (nb_segs_left = nb_segs; nb_segs_left; nb_segs_left--)
      {
        if (PREDICT_FALSE(pkt_mb == 0))
  	{
  	  clib_warning ("Missing %d mbuf chain segment(s):   "
  			"(nb_segs = %d, nb_segs_left = %d)!",
  			nb_segs - nb_segs_left, nb_segs, nb_segs_left);
  	  if (first_mb)
  	    rte_pktmbuf_free(first_mb);
  	  return NULL;
  	}
        new_mb = rte_pktmbuf_alloc (bm->pktmbuf_pools[socket_id]);
        if (PREDICT_FALSE(new_mb == 0))
  	{
  	  if (first_mb)
  	    rte_pktmbuf_free(first_mb);
  	  return NULL;
  	}
        
        /*
         * Copy packet info into 1st segment.
         */
        if (first_mb == 0)
  	{
  	  first_mb = new_mb;
  	  rte_pktmbuf_pkt_len (first_mb) = pkt_mb->pkt_len;
  	  first_mb->nb_segs = pkt_mb->nb_segs;
  	  first_mb->port = pkt_mb->port;
  #ifdef DAW_FIXME // TX Offload support TBD
  	  first_mb->vlan_macip = pkt_mb->vlan_macip;
  	  first_mb->hash = pkt_mb->hash;
  	  first_mb->ol_flags = pkt_mb->ol_flags
  #endif
  	}
        else
  	{
  	  ASSERT(prev_mb_next != 0);
  	  *prev_mb_next = new_mb;
  	}
        
        /*
         * Copy packet segment data into new mbuf segment.
         */
        rte_pktmbuf_data_len (new_mb) = pkt_mb->data_len;
        copy_bytes = pkt_mb->data_len + RTE_PKTMBUF_HEADROOM;
        ASSERT(copy_bytes <= pkt_mb->buf_len);
        clib_memcpy(new_mb->buf_addr, pkt_mb->buf_addr, copy_bytes);
  
        prev_mb_next = &new_mb->next;
        pkt_mb = pkt_mb->next;
      }
  
    ASSERT(pkt_mb == 0);
    __rte_mbuf_sanity_check(first_mb, 1);
  
    return first_mb;
  }
  
  struct rte_mbuf * dpdk_zerocopy_replicate_packet_mb (vlib_buffer_t * b)
  {
    vlib_main_t * vm = vlib_get_main();
    vlib_buffer_main_t * bm = vm->buffer_main;
    struct rte_mbuf * first_mb = 0, * new_mb, * pkt_mb, ** prev_mb_next = 0;
    u8 nb_segs, nb_segs_left;
    unsigned socket_id = rte_socket_id();
  
    ASSERT (bm->pktmbuf_pools[socket_id]);
    pkt_mb = rte_mbuf_from_vlib_buffer(b);
    nb_segs = pkt_mb->nb_segs;
    for (nb_segs_left = nb_segs; nb_segs_left; nb_segs_left--)
      {
        if (PREDICT_FALSE(pkt_mb == 0))
  	{
  	  clib_warning ("Missing %d mbuf chain segment(s):   "
  			"(nb_segs = %d, nb_segs_left = %d)!",
  			nb_segs - nb_segs_left, nb_segs, nb_segs_left);
  	  if (first_mb)
  	    rte_pktmbuf_free(first_mb);
  	  return NULL;
  	}
        new_mb = rte_pktmbuf_clone(pkt_mb, bm->pktmbuf_pools[socket_id]);
        if (PREDICT_FALSE(new_mb == 0))
  	{
  	  if (first_mb)
  	    rte_pktmbuf_free(first_mb);
  	  return NULL;
  	}
        
        /*
         * Copy packet info into 1st segment.
         */
        if (first_mb == 0)
  	{
  	  first_mb = new_mb;
  	  rte_pktmbuf_pkt_len (first_mb) = pkt_mb->pkt_len;
  	  first_mb->nb_segs = pkt_mb->nb_segs;
  	  first_mb->port = pkt_mb->port;
  #ifdef DAW_FIXME // TX Offload support TBD
  	  first_mb->vlan_macip = pkt_mb->vlan_macip;
  	  first_mb->hash = pkt_mb->hash;
  	  first_mb->ol_flags = pkt_mb->ol_flags
  #endif
  	}
        else
  	{
  	  ASSERT(prev_mb_next != 0);
  	  *prev_mb_next = new_mb;
  	}
        
        /*
         * Copy packet segment data into new mbuf segment.
         */
        rte_pktmbuf_data_len (new_mb) = pkt_mb->data_len;
  
        prev_mb_next = &new_mb->next;
        pkt_mb = pkt_mb->next;
      }
  
    ASSERT(pkt_mb == 0);
    __rte_mbuf_sanity_check(first_mb, 1);
  
    return first_mb;
  
  
  }
  
  static void
  dpdk_tx_trace_buffer (dpdk_main_t * dm,
  		      vlib_node_runtime_t * node,
  		      dpdk_device_t * xd,
  		      u16 queue_id,
  		      u32 buffer_index,
  		      vlib_buffer_t * buffer)
  {
    vlib_main_t * vm = vlib_get_main();
    dpdk_tx_dma_trace_t * t0;
    struct rte_mbuf * mb;
  
    mb = rte_mbuf_from_vlib_buffer(buffer);
  
    t0 = vlib_add_trace (vm, node, buffer, sizeof (t0[0]));
    t0->queue_index = queue_id;
    t0->device_index = xd->device_index;
    t0->buffer_index = buffer_index;
    clib_memcpy (&t0->mb, mb, sizeof (t0->mb));
    clib_memcpy (&t0->buffer, buffer, sizeof (buffer[0]) - sizeof (buffer->pre_data));
    clib_memcpy (t0->buffer.pre_data, buffer->data + buffer->current_data,
  	  sizeof (t0->buffer.pre_data));
  }
  
  /*
   * This function calls the dpdk's tx_burst function to transmit the packets
   * on the tx_vector. It manages a lock per-device if the device does not
   * support multiple queues. It returns the number of packets untransmitted 
   * on the tx_vector. If all packets are transmitted (the normal case), the 
   * function returns 0.
   * 
   * The tx_burst function may not be able to transmit all packets because the 
   * dpdk ring is full. If a flowcontrol callback function has been configured
   * then the function simply returns. If no callback has been configured, the 
   * function will retry calling tx_burst with the remaining packets. This will 
   * continue until all packets are transmitted or tx_burst indicates no packets
   * could be transmitted. (The caller can drop the remaining packets.)
   *
   * The function assumes there is at least one packet on the tx_vector.
   */
  static_always_inline
  u32 tx_burst_vector_internal (vlib_main_t * vm, 
                                dpdk_device_t * xd,
                                struct rte_mbuf ** tx_vector)
  {
    dpdk_main_t * dm = &dpdk_main;
    u32 n_packets;
    u32 tx_head;
    u32 tx_tail;
    u32 n_retry;
    int rv;
    int queue_id;
    tx_ring_hdr_t *ring;
  
    ring = vec_header(tx_vector, sizeof(*ring));
  
    n_packets = ring->tx_head - ring->tx_tail;
  
    tx_head = ring->tx_head % DPDK_TX_RING_SIZE;
  
    /*
     * Ensure rte_eth_tx_burst is not called with 0 packets, which can lead to
     * unpredictable results.
     */
    ASSERT(n_packets > 0);
  
    /*
     * Check for tx_vector overflow. If this fails it is a system configuration
     * error. The ring should be sized big enough to handle the largest un-flowed
     * off burst from a traffic manager. A larger size also helps performance
     * a bit because it decreases the probability of having to issue two tx_burst
     * calls due to a ring wrap.
     */
    ASSERT(n_packets < DPDK_TX_RING_SIZE);
  
    /*
     * If there is no flowcontrol callback, there is only temporary buffering
     * on the tx_vector and so the tail should always be 0.
     */
    ASSERT(dm->flowcontrol_callback || ring->tx_tail == 0);
  
    /*
     * If there is a flowcontrol callback, don't retry any incomplete tx_bursts. 
     * Apply backpressure instead. If there is no callback, keep retrying until
     * a tx_burst sends no packets. n_retry of 255 essentially means no retry 
     * limit.
     */
    n_retry = dm->flowcontrol_callback ? 0 : 255;
  
    queue_id = vm->cpu_index;
  
    do {
        /* start the burst at the tail */
        tx_tail = ring->tx_tail % DPDK_TX_RING_SIZE;
  
        /* 
         * This device only supports one TX queue,
         * and we're running multi-threaded...
         */
        if (PREDICT_FALSE(xd->dev_type != VNET_DPDK_DEV_VHOST_USER &&
          xd->lockp != 0))
          {
            queue_id = queue_id % xd->tx_q_used;
            while (__sync_lock_test_and_set (xd->lockp[queue_id], 1))
              /* zzzz */
              queue_id = (queue_id + 1) % xd->tx_q_used;
          }
  
        if (PREDICT_TRUE(xd->dev_type == VNET_DPDK_DEV_ETH)) 
          {
            if (PREDICT_TRUE(tx_head > tx_tail)) 
              {
                /* no wrap, transmit in one burst */
                rv = rte_eth_tx_burst(xd->device_index, 
                                      (uint16_t) queue_id,
                                      &tx_vector[tx_tail], 
                                      (uint16_t) (tx_head-tx_tail));
              }
            else 
              {
                /* 
                 * This can only happen if there is a flowcontrol callback.
                 * We need to split the transmit into two calls: one for
                 * the packets up to the wrap point, and one to continue
                 * at the start of the ring.
                 * Transmit pkts up to the wrap point.
                 */
                rv = rte_eth_tx_burst(xd->device_index, 
                                      (uint16_t) queue_id,
                                      &tx_vector[tx_tail], 
                                      (uint16_t) (DPDK_TX_RING_SIZE - tx_tail));
  
                /* 
                 * If we transmitted everything we wanted, then allow 1 retry 
                 * so we can try to transmit the rest. If we didn't transmit
                 * everything, stop now.
                 */
                n_retry = (rv == DPDK_TX_RING_SIZE - tx_tail) ? 1 : 0;
              }
          } 
        else if (xd->dev_type == VNET_DPDK_DEV_VHOST_USER)
          {
            u32 offset = 0;
            if (xd->need_txlock) {
              queue_id = 0;
              while (__sync_lock_test_and_set (xd->lockp[queue_id], 1));
            }
            else {
                dpdk_device_and_queue_t * dq;
                vec_foreach (dq, dm->devices_by_cpu[vm->cpu_index])
                {
                  if (xd->device_index == dq->device)
                      break; 
                }
                assert (dq);
                offset = dq->queue_id * VIRTIO_QNUM;
            }
            if (PREDICT_TRUE(tx_head > tx_tail)) 
              {
                int i; u32 bytes = 0;
                struct rte_mbuf **pkts = &tx_vector[tx_tail];
                for (i = 0; i < (tx_head - tx_tail); i++) {
                    struct rte_mbuf *buff = pkts[i];
                    bytes += rte_pktmbuf_data_len(buff);
                } 
                  
                /* no wrap, transmit in one burst */
                rv = rte_vhost_enqueue_burst(&xd->vu_vhost_dev, offset + VIRTIO_RXQ,
                                             &tx_vector[tx_tail],
                                             (uint16_t) (tx_head-tx_tail));
                if (PREDICT_TRUE(rv > 0))
                  {
                    dpdk_vu_vring *vring = &(xd->vu_intf->vrings[offset + VIRTIO_TXQ]);
                    vring->packets += rv;
                    vring->bytes += bytes;
  
                    if (dpdk_vhost_user_want_interrupt(xd, offset + VIRTIO_RXQ)) {
                      vring = &(xd->vu_intf->vrings[offset + VIRTIO_RXQ]);
                      vring->n_since_last_int += rv;
  
                      f64 now = vlib_time_now (vm);
                      if (vring->int_deadline < now ||
                          vring->n_since_last_int > dm->conf->vhost_coalesce_frames)
                        dpdk_vhost_user_send_interrupt(vm, xd, offset + VIRTIO_RXQ);
                    }
  
                    int c = rv;
                    while(c--)
                      rte_pktmbuf_free (tx_vector[tx_tail+c]);
                  }
              }
            else
              {
                /*
                 * If we transmitted everything we wanted, then allow 1 retry
                 * so we can try to transmit the rest. If we didn't transmit
                 * everything, stop now.
                 */
                int i; u32 bytes = 0;
                struct rte_mbuf **pkts = &tx_vector[tx_tail];
                for (i = 0; i < (DPDK_TX_RING_SIZE - tx_tail); i++) {
                    struct rte_mbuf *buff = pkts[i];
                    bytes += rte_pktmbuf_data_len(buff);
                }
                rv = rte_vhost_enqueue_burst(&xd->vu_vhost_dev, offset + VIRTIO_RXQ,
                                             &tx_vector[tx_tail], 
                                             (uint16_t) (DPDK_TX_RING_SIZE - tx_tail));
  
                if (PREDICT_TRUE(rv > 0))
                  {
                    dpdk_vu_vring *vring = &(xd->vu_intf->vrings[offset + VIRTIO_TXQ]);
                    vring->packets += rv;
                    vring->bytes += bytes;
  
                    if (dpdk_vhost_user_want_interrupt(xd, offset + VIRTIO_RXQ)) {
                      vring = &(xd->vu_intf->vrings[offset + VIRTIO_RXQ]);
                      vring->n_since_last_int += rv;
  
                      f64 now = vlib_time_now (vm);
                      if (vring->int_deadline < now ||
                          vring->n_since_last_int > dm->conf->vhost_coalesce_frames)
                        dpdk_vhost_user_send_interrupt(vm, xd, offset + VIRTIO_RXQ);
                    }
  
                    int c = rv;
                    while(c--)
                      rte_pktmbuf_free (tx_vector[tx_tail+c]);
                  }
  
                n_retry = (rv == DPDK_TX_RING_SIZE - tx_tail) ? 1 : 0;
              }
  
            if (xd->need_txlock)
              *xd->lockp[queue_id] = 0;
          }
  #if RTE_LIBRTE_KNI
        else if (xd->dev_type == VNET_DPDK_DEV_KNI)
          {
            if (PREDICT_TRUE(tx_head > tx_tail)) 
              {
                /* no wrap, transmit in one burst */
                rv = rte_kni_tx_burst(xd->kni, 
                                      &tx_vector[tx_tail], 
                                      (uint16_t) (tx_head-tx_tail));
              }
            else 
              {
                /* 
                 * This can only happen if there is a flowcontrol callback.
                 * We need to split the transmit into two calls: one for
                 * the packets up to the wrap point, and one to continue
                 * at the start of the ring.
                 * Transmit pkts up to the wrap point.
                 */
                rv = rte_kni_tx_burst(xd->kni, 
                                      &tx_vector[tx_tail], 
                                      (uint16_t) (DPDK_TX_RING_SIZE - tx_tail));
  
                /* 
                 * If we transmitted everything we wanted, then allow 1 retry 
                 * so we can try to transmit the rest. If we didn't transmit
                 * everything, stop now.
                 */
                n_retry = (rv == DPDK_TX_RING_SIZE - tx_tail) ? 1 : 0;
              }
          } 
  #endif
        else
          {
            ASSERT(0);
            rv = 0;
          }
  
        if (PREDICT_FALSE(xd->dev_type != VNET_DPDK_DEV_VHOST_USER &&
              xd->lockp != 0))
            *xd->lockp[queue_id] = 0;
  
        if (PREDICT_FALSE(rv < 0))
          {
            // emit non-fatal message, bump counter
            vnet_main_t * vnm = dm->vnet_main;
            vnet_interface_main_t * im = &vnm->interface_main;
            u32 node_index;
  
            node_index = vec_elt_at_index(im->hw_interfaces, 
                                          xd->vlib_hw_if_index)->tx_node_index;
  
            vlib_error_count (vm, node_index, DPDK_TX_FUNC_ERROR_BAD_RETVAL, 1);
            clib_warning ("rte_eth_tx_burst[%d]: error %d", xd->device_index, rv);
            return n_packets; // untransmitted packets
          }
        ring->tx_tail += (u16)rv;
        n_packets -= (uint16_t) rv;
    } while (rv && n_packets && (n_retry>0));
  
    return n_packets;
  }
  
  
  /*
   * This function transmits any packets on the interface's tx_vector and returns
   * the number of packets untransmitted on the tx_vector. If the tx_vector is 
   * empty the function simply returns 0. 
   *
   * It is intended to be called by a traffic manager which has flowed-off an
   * interface to see if the interface can be flowed-on again.
   */
  u32 dpdk_interface_tx_vector (vlib_main_t * vm, u32 dev_instance)
  {
    dpdk_main_t * dm = &dpdk_main;
    dpdk_device_t * xd;
    int queue_id;
    struct rte_mbuf ** tx_vector;
    tx_ring_hdr_t *ring;
   
    /* param is dev_instance and not hw_if_index to save another lookup */
    xd = vec_elt_at_index (dm->devices, dev_instance);
  
    queue_id = vm->cpu_index;
    tx_vector = xd->tx_vectors[queue_id];
  
    /* If no packets on the ring, don't bother calling tx function */
    ring = vec_header(tx_vector, sizeof(*ring));
    if (ring->tx_head == ring->tx_tail) 
      {
        return 0;
      }
  
    return tx_burst_vector_internal (vm, xd, tx_vector);
  }
  
  /*
   * Transmits the packets on the frame to the interface associated with the
   * node. It first copies packets on the frame to a tx_vector containing the 
   * rte_mbuf pointers. It then passes this vector to tx_burst_vector_internal 
   * which calls the dpdk tx_burst function.
   *
   * The tx_vector is treated slightly differently depending on whether or
   * not a flowcontrol callback function has been configured. If there is no
   * callback, the tx_vector is a temporary array of rte_mbuf packet pointers.
   * Its entries are written and consumed before the function exits. 
   *
   * If there is a callback then the transmit is being invoked in the presence
   * of a traffic manager. Here the tx_vector is treated like a ring of rte_mbuf
   * pointers. If not all packets can be transmitted, the untransmitted packets
   * stay on the tx_vector until the next call. The callback allows the traffic
   * manager to flow-off dequeues to the interface. The companion function
   * dpdk_interface_tx_vector() allows the traffic manager to detect when
   * it should flow-on the interface again.
   */
  static uword
  dpdk_interface_tx (vlib_main_t * vm,
             vlib_node_runtime_t * node,
             vlib_frame_t * f)
  {
    dpdk_main_t * dm = &dpdk_main;
    vnet_interface_output_runtime_t * rd = (void *) node->runtime_data;
    dpdk_device_t * xd = vec_elt_at_index (dm->devices, rd->dev_instance);
    u32 n_packets = f->n_vectors;
    u32 n_left;
    u32 * from;
    struct rte_mbuf ** tx_vector;
    int i;
    int queue_id;
    u32 my_cpu;
    u32 tx_pkts = 0;
    tx_ring_hdr_t *ring;
    u32 n_on_ring;
  
    my_cpu = vm->cpu_index;
  
    queue_id = my_cpu;
  
    tx_vector = xd->tx_vectors[queue_id];
    ring = vec_header(tx_vector, sizeof(*ring));
  
    n_on_ring = ring->tx_head - ring->tx_tail;
    from = vlib_frame_vector_args (f);
  
    ASSERT(n_packets <= VLIB_FRAME_SIZE);
  
    if (PREDICT_FALSE(n_on_ring + n_packets > DPDK_TX_RING_SIZE))
      {
        /*
         * Overflowing the ring should never happen. 
         * If it does then drop the whole frame.
         */
        vlib_error_count (vm, node->node_index, DPDK_TX_FUNC_ERROR_RING_FULL,
                          n_packets);
  
        while (n_packets--) 
          {
            u32 bi0 = from[n_packets];
            vlib_buffer_t *b0 = vlib_get_buffer (vm, bi0);
            struct rte_mbuf *mb0 = rte_mbuf_from_vlib_buffer(b0);
            rte_pktmbuf_free (mb0);
          }
        return n_on_ring;
      }
  
    if (PREDICT_FALSE(dm->tx_pcap_enable))
      {
        n_left = n_packets;
        while (n_left > 0)
          {
  	  u32 bi0 = from[0];
  	  vlib_buffer_t * b0 = vlib_get_buffer (vm, bi0);
  	  if (dm->pcap_sw_if_index == 0 ||
  	      dm->pcap_sw_if_index == vnet_buffer(b0)->sw_if_index [VLIB_TX])
  	      pcap_add_buffer (&dm->pcap_main, vm, bi0, 512);
  	  from++;
  	  n_left--;
  	}
      }
  
    from = vlib_frame_vector_args (f);
    n_left = n_packets;
    i = ring->tx_head % DPDK_TX_RING_SIZE;
  
    while (n_left >= 4)
      {
        u32 bi0, bi1;
        u32 pi0, pi1;
        struct rte_mbuf * mb0, * mb1;
        struct rte_mbuf * prefmb0, * prefmb1;
        vlib_buffer_t * b0, * b1;
        vlib_buffer_t * pref0, * pref1;
        i16 delta0, delta1;
        u16 new_data_len0, new_data_len1;
        u16 new_pkt_len0, new_pkt_len1;
        u32 any_clone;
  
        pi0 = from[2];
        pi1 = from[3];
        pref0 = vlib_get_buffer (vm, pi0);
        pref1 = vlib_get_buffer (vm, pi1);
  
        prefmb0 = rte_mbuf_from_vlib_buffer(pref0);
        prefmb1 = rte_mbuf_from_vlib_buffer(pref1);
  
        CLIB_PREFETCH(prefmb0, CLIB_CACHE_LINE_BYTES, LOAD);
        CLIB_PREFETCH(pref0, CLIB_CACHE_LINE_BYTES, LOAD);
        CLIB_PREFETCH(prefmb1, CLIB_CACHE_LINE_BYTES, LOAD);
        CLIB_PREFETCH(pref1, CLIB_CACHE_LINE_BYTES, LOAD);
  
        bi0 = from[0];
        bi1 = from[1];
        from += 2;
        
        b0 = vlib_get_buffer (vm, bi0);
        b1 = vlib_get_buffer (vm, bi1);
  
        mb0 = rte_mbuf_from_vlib_buffer(b0);
        mb1 = rte_mbuf_from_vlib_buffer(b1);
  
        any_clone = (b0->flags & VLIB_BUFFER_RECYCLE)
            | (b1->flags & VLIB_BUFFER_RECYCLE);
        if (PREDICT_FALSE(any_clone != 0))
          {
              if (PREDICT_FALSE
                  ((b0->flags & VLIB_BUFFER_RECYCLE) != 0))
  	    {
  	      struct rte_mbuf * mb0_new = dpdk_replicate_packet_mb (b0);
  	      if (PREDICT_FALSE(mb0_new == 0))
  		{
  		  vlib_error_count (vm, node->node_index,
  				    DPDK_TX_FUNC_ERROR_REPL_FAIL, 1);
  		  b0->flags |= VLIB_BUFFER_REPL_FAIL;
  		}
  	      else
  		mb0 = mb0_new;
  	      vec_add1 (dm->recycle[my_cpu], bi0);
  	    }
            if (PREDICT_FALSE
                ((b1->flags & VLIB_BUFFER_RECYCLE) != 0))
  	    {
  	      struct rte_mbuf * mb1_new = dpdk_replicate_packet_mb (b1);
  	      if (PREDICT_FALSE(mb1_new == 0))
  		{
  		  vlib_error_count (vm, node->node_index,
  				    DPDK_TX_FUNC_ERROR_REPL_FAIL, 1);
  		  b1->flags |= VLIB_BUFFER_REPL_FAIL;
  		}
  	      else
  		mb1 = mb1_new;
  	      vec_add1 (dm->recycle[my_cpu], bi1);
  	    }
  	}
  
        delta0 = PREDICT_FALSE(b0->flags & VLIB_BUFFER_REPL_FAIL) ? 0 :
  	vlib_buffer_length_in_chain (vm, b0) - (i16) mb0->pkt_len;
        delta1 = PREDICT_FALSE(b1->flags & VLIB_BUFFER_REPL_FAIL) ? 0 :
  	vlib_buffer_length_in_chain (vm, b1) - (i16) mb1->pkt_len;
        
        new_data_len0 = (u16)((i16) mb0->data_len + delta0);
        new_data_len1 = (u16)((i16) mb1->data_len + delta1);
        new_pkt_len0 = (u16)((i16) mb0->pkt_len + delta0);
        new_pkt_len1 = (u16)((i16) mb1->pkt_len + delta1);
  
        b0->current_length = new_data_len0;
        b1->current_length = new_data_len1;
        mb0->data_len = new_data_len0;
        mb1->data_len = new_data_len1;
        mb0->pkt_len = new_pkt_len0;
        mb1->pkt_len = new_pkt_len1;
  
        mb0->data_off = (PREDICT_FALSE(b0->flags & VLIB_BUFFER_REPL_FAIL)) ?
  	mb0->data_off : (u16)(RTE_PKTMBUF_HEADROOM + b0->current_data);
        mb1->data_off = (PREDICT_FALSE(b1->flags & VLIB_BUFFER_REPL_FAIL)) ?
  	mb1->data_off : (u16)(RTE_PKTMBUF_HEADROOM + b1->current_data);
  
        if (PREDICT_FALSE(node->flags & VLIB_NODE_FLAG_TRACE))
  	{
            if (b0->flags & VLIB_BUFFER_IS_TRACED)
  	    dpdk_tx_trace_buffer (dm, node, xd, queue_id, bi0, b0);
            if (b1->flags & VLIB_BUFFER_IS_TRACED)
  	    dpdk_tx_trace_buffer (dm, node, xd, queue_id, bi1, b1);
  	}
  
        if (PREDICT_TRUE(any_clone == 0))
          {
  	  tx_vector[i % DPDK_TX_RING_SIZE] = mb0;
            i++;
  	  tx_vector[i % DPDK_TX_RING_SIZE] = mb1;
            i++;
          }
        else
          {
            /* cloning was done, need to check for failure */
            if (PREDICT_TRUE((b0->flags & VLIB_BUFFER_REPL_FAIL) == 0))
              {
  	      tx_vector[i % DPDK_TX_RING_SIZE] = mb0;
                i++;
              }
            if (PREDICT_TRUE((b1->flags & VLIB_BUFFER_REPL_FAIL) == 0))
              {
  	      tx_vector[i % DPDK_TX_RING_SIZE] = mb1;
                i++;
              }
          }
        
        n_left -= 2;
      }
    while (n_left > 0)
      {
        u32 bi0;
        struct rte_mbuf * mb0;
        vlib_buffer_t * b0;
        i16 delta0;
        u16 new_data_len0;
        u16 new_pkt_len0;
  
        bi0 = from[0];
        from++;
        
        b0 = vlib_get_buffer (vm, bi0);
  
        mb0 = rte_mbuf_from_vlib_buffer(b0);
        if (PREDICT_FALSE((b0->flags & VLIB_BUFFER_RECYCLE) != 0))
  	{
  	  struct rte_mbuf * mb0_new = dpdk_replicate_packet_mb (b0);
  	  if (PREDICT_FALSE(mb0_new == 0))
  	    {
  	      vlib_error_count (vm, node->node_index,
  				DPDK_TX_FUNC_ERROR_REPL_FAIL, 1);
  	      b0->flags |= VLIB_BUFFER_REPL_FAIL;
  	    }
  	  else
  	    mb0 = mb0_new;
  	  vec_add1 (dm->recycle[my_cpu], bi0);
  	}
  
        delta0 = PREDICT_FALSE(b0->flags & VLIB_BUFFER_REPL_FAIL) ? 0 :
  	vlib_buffer_length_in_chain (vm, b0) - (i16) mb0->pkt_len;
        
        new_data_len0 = (u16)((i16) mb0->data_len + delta0);
        new_pkt_len0 = (u16)((i16) mb0->pkt_len + delta0);
        
        b0->current_length = new_data_len0;
        mb0->data_len = new_data_len0;
        mb0->pkt_len = new_pkt_len0;
        mb0->data_off = (PREDICT_FALSE(b0->flags & VLIB_BUFFER_REPL_FAIL)) ?
  	mb0->data_off : (u16)(RTE_PKTMBUF_HEADROOM + b0->current_data);
  
        if (PREDICT_FALSE(node->flags & VLIB_NODE_FLAG_TRACE))
  	if (b0->flags & VLIB_BUFFER_IS_TRACED)
  	  dpdk_tx_trace_buffer (dm, node, xd, queue_id, bi0, b0);
  
        if (PREDICT_TRUE((b0->flags & VLIB_BUFFER_REPL_FAIL) == 0))
          {
  	  tx_vector[i % DPDK_TX_RING_SIZE] = mb0;
            i++;
          }
        n_left--;
      }
  
    /* account for additional packets in the ring */
    ring->tx_head += n_packets;
    n_on_ring = ring->tx_head - ring->tx_tail;
  
    /* transmit as many packets as possible */
    n_packets = tx_burst_vector_internal (vm, xd, tx_vector);
  
    /*
     * tx_pkts is the number of packets successfully transmitted
     * This is the number originally on ring minus the number remaining on ring
     */
    tx_pkts = n_on_ring - n_packets; 
  
    if (PREDICT_FALSE(dm->flowcontrol_callback != 0))
      {
        if (PREDICT_FALSE(n_packets))
          {
            /* Callback may want to enable flowcontrol */
            dm->flowcontrol_callback(vm, xd->vlib_hw_if_index, ring->tx_head - ring->tx_tail);
          } 
        else 
          {
            /* Reset head/tail to avoid unnecessary wrap */
            ring->tx_head = 0;
            ring->tx_tail = 0;
          }
      }
    else 
      {
        /* If there is no callback then drop any non-transmitted packets */
        if (PREDICT_FALSE(n_packets))
          {
            vlib_simple_counter_main_t * cm;
            vnet_main_t * vnm = vnet_get_main();
  
            cm = vec_elt_at_index (vnm->interface_main.sw_if_counters,
                                   VNET_INTERFACE_COUNTER_TX_ERROR);
  
            vlib_increment_simple_counter (cm, my_cpu, xd->vlib_sw_if_index, n_packets);
  
            vlib_error_count (vm, node->node_index, DPDK_TX_FUNC_ERROR_PKT_DROP,
  			    n_packets);
  
            while (n_packets--)
              rte_pktmbuf_free (tx_vector[ring->tx_tail + n_packets]);
          }
  
          /* Reset head/tail to avoid unnecessary wrap */
        ring->tx_head = 0;
        ring->tx_tail = 0;
      }
  
    /* Recycle replicated buffers */
    if (PREDICT_FALSE(vec_len(dm->recycle[my_cpu])))
      {
        vlib_buffer_free (vm, dm->recycle[my_cpu], vec_len(dm->recycle[my_cpu]));
        _vec_len(dm->recycle[my_cpu]) = 0;
      }
  
    ASSERT(ring->tx_head >= ring->tx_tail);
  
    return tx_pkts;
  }
  
  static int dpdk_device_renumber (vnet_hw_interface_t * hi,
                                   u32 new_dev_instance)
  {
    dpdk_main_t * dm = &dpdk_main;
    dpdk_device_t * xd = vec_elt_at_index (dm->devices, hi->dev_instance);
  
    if (!xd || xd->dev_type != VNET_DPDK_DEV_VHOST_USER) {
      clib_warning("cannot renumber non-vhost-user interface (sw_if_index: %d)",
  		 hi->sw_if_index);
      return 0;
    }
  
    xd->vu_if_id = new_dev_instance;
    return 0;
  }
  
  static void dpdk_clear_hw_interface_counters (u32 instance)
  {
    dpdk_main_t * dm = &dpdk_main;
    dpdk_device_t * xd = vec_elt_at_index (dm->devices, instance);
  
    /*
     * DAW-FIXME: VMXNET3 device stop/start doesn't work, 
     * therefore fake the stop in the dpdk driver by
     * silently dropping all of the incoming pkts instead of 
     * stopping the driver / hardware.
     */
    if (xd->admin_up != 0xff)
      {
        /*
         * Set the "last_cleared_stats" to the current stats, so that
         * things appear to clear from a display perspective.
         */
        dpdk_update_counters (xd, vlib_time_now (dm->vlib_main));
  
        clib_memcpy (&xd->last_cleared_stats, &xd->stats, sizeof(xd->stats));
        clib_memcpy (xd->last_cleared_xstats, xd->xstats,
  	      vec_len(xd->last_cleared_xstats) *
  	      sizeof(xd->last_cleared_xstats[0]));
      }
    else
      {
        /*
         * Internally rte_eth_xstats_reset() is calling rte_eth_stats_reset(),
         * so we're only calling xstats_reset() here.
         */
        rte_eth_xstats_reset (xd->device_index);
        memset (&xd->stats, 0, sizeof(xd->stats));
        memset (&xd->last_stats, 0, sizeof (xd->last_stats));
      }
  
    if (PREDICT_FALSE(xd->dev_type == VNET_DPDK_DEV_VHOST_USER)) {
      int i;
      for (i = 0; i < xd->rx_q_used * VIRTIO_QNUM; i++) {
        xd->vu_intf->vrings[i].packets = 0;
        xd->vu_intf->vrings[i].bytes = 0;
      }
    }
  }
  
  #ifdef RTE_LIBRTE_KNI
  static int
  kni_config_network_if(u8 port_id, u8 if_up)
  {
    vnet_main_t * vnm = vnet_get_main();
    dpdk_main_t * dm = &dpdk_main;
    dpdk_device_t * xd;
    uword *p;
  
    p = hash_get (dm->dpdk_device_by_kni_port_id, port_id);
    if (p == 0) {
      clib_warning("unknown interface");
      return 0;
    } else {
      xd = vec_elt_at_index (dm->devices, p[0]);
    }
  
    vnet_hw_interface_set_flags (vnm, xd->vlib_hw_if_index,
                                 if_up ? VNET_HW_INTERFACE_FLAG_LINK_UP |
                                 ETH_LINK_FULL_DUPLEX : 0);
    return 0;
  }
  
  static int
  kni_change_mtu(u8 port_id, unsigned new_mtu)
  {
    vnet_main_t * vnm = vnet_get_main();
    dpdk_main_t * dm = &dpdk_main;
    dpdk_device_t * xd;
    uword *p;
    vnet_hw_interface_t * hif;
  
    p = hash_get (dm->dpdk_device_by_kni_port_id, port_id);
    if (p == 0) {
      clib_warning("unknown interface");
      return 0;
    } else {
      xd = vec_elt_at_index (dm->devices, p[0]);
    }
    hif = vnet_get_hw_interface (vnm, xd->vlib_hw_if_index);
  
    hif->max_packet_bytes = new_mtu;
  
    return 0;
  }
  #endif
  
  static clib_error_t *
  dpdk_interface_admin_up_down (vnet_main_t * vnm, u32 hw_if_index, u32 flags)
  {
    vnet_hw_interface_t * hif = vnet_get_hw_interface (vnm, hw_if_index);
    uword is_up = (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP) != 0;
    dpdk_main_t * dm = &dpdk_main;
    dpdk_device_t * xd = vec_elt_at_index (dm->devices, hif->dev_instance);
    int rv = 0;
  
  #ifdef RTE_LIBRTE_KNI
    if (xd->dev_type == VNET_DPDK_DEV_KNI)
    {
        if (is_up)
        {
            struct rte_kni_conf conf;
            struct rte_kni_ops ops;
            vlib_main_t * vm = vlib_get_main();
            vlib_buffer_main_t * bm = vm->buffer_main;
            memset(&conf, 0, sizeof(conf));
            snprintf(conf.name, RTE_KNI_NAMESIZE, "vpp%u", xd->kni_port_id);
            conf.mbuf_size = VLIB_BUFFER_DATA_SIZE;
            memset(&ops, 0, sizeof(ops));
            ops.port_id = xd->kni_port_id;
            ops.change_mtu = kni_change_mtu;
            ops.config_network_if = kni_config_network_if;
  
            xd->kni = rte_kni_alloc(bm->pktmbuf_pools[rte_socket_id()], &conf, &ops);
            if (!xd->kni)
            {
              clib_warning("failed to allocate kni interface");
            }
            else
            {
              hif->max_packet_bytes = 1500; /* kni interface default value */
              xd->admin_up = 1;
            }
        }
        else
        {
          xd->admin_up = 0;
          rte_kni_release(xd->kni);
        }
        return 0;
    }
  #endif
    if (xd->dev_type == VNET_DPDK_DEV_VHOST_USER)
      {
        if (is_up)
          {
            if (xd->vu_is_running)
              vnet_hw_interface_set_flags (vnm, xd->vlib_hw_if_index,
                                   VNET_HW_INTERFACE_FLAG_LINK_UP |
                                   ETH_LINK_FULL_DUPLEX );
            xd->admin_up = 1;
          }
        else
          {
            vnet_hw_interface_set_flags (vnm, xd->vlib_hw_if_index, 0);
                                xd->admin_up = 0;
          }
  
        return 0;
      }
  
  
    if (is_up)
      {
        f64 now = vlib_time_now (dm->vlib_main);
  
        /*
         * DAW-FIXME: VMXNET3 device stop/start doesn't work, 
         * therefore fake the stop in the dpdk driver by
         * silently dropping all of the incoming pkts instead of 
         * stopping the driver / hardware.
         */
        if (xd->admin_up == 0)
  	rv = rte_eth_dev_start (xd->device_index);
  
        if (xd->promisc)
  	  rte_eth_promiscuous_enable(xd->device_index);
        else
  	  rte_eth_promiscuous_disable(xd->device_index);
  
        rte_eth_allmulticast_enable (xd->device_index);
        xd->admin_up = 1;
        dpdk_update_counters (xd, now);
        dpdk_update_link_state (xd, now);
      }
    else
      {
        /*
         * DAW-FIXME: VMXNET3 device stop/start doesn't work,
         * therefore fake the stop in the dpdk driver by
         * silently dropping all of the incoming pkts instead of
         * stopping the driver / hardware.
         */
        if (xd->pmd != VNET_DPDK_PMD_VMXNET3)
           xd->admin_up = 0;
        else
           xd->admin_up = ~0;
  
        rte_eth_allmulticast_disable (xd->device_index);
        vnet_hw_interface_set_flags (vnm, xd->vlib_hw_if_index, 0);
  
        /*
         * DAW-FIXME: VMXNET3 device stop/start doesn't work, 
         * therefore fake the stop in the dpdk driver by
         * silently dropping all of the incoming pkts instead of 
         * stopping the driver / hardware.
         */
        if (xd->pmd != VNET_DPDK_PMD_VMXNET3)
  	  rte_eth_dev_stop (xd->device_index);
      }
  
    if (rv < 0)
      clib_warning ("rte_eth_dev_%s error: %d", is_up ? "start" : "stop",
                    rv);
  
    return /* no error */ 0;
  }
  
  /*
   * Dynamically redirect all pkts from a specific interface
   * to the specified node
   */
  static void dpdk_set_interface_next_node (vnet_main_t *vnm, u32 hw_if_index,
                                            u32 node_index)
  {
    dpdk_main_t * xm = &dpdk_main;
    vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
    dpdk_device_t * xd = vec_elt_at_index (xm->devices, hw->dev_instance);
    
    /* Shut off redirection */
    if (node_index == ~0)
      {
        xd->per_interface_next_index = node_index;
        return;
      }
    
    xd->per_interface_next_index = 
      vlib_node_add_next (xm->vlib_main, dpdk_input_node.index, node_index);
  }
  
  
  static clib_error_t *
  dpdk_subif_add_del_function (vnet_main_t * vnm,
                               u32 hw_if_index,
                               struct vnet_sw_interface_t * st,
                               int is_add)
  {
    dpdk_main_t * xm = &dpdk_main;
    vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
    dpdk_device_t * xd = vec_elt_at_index (xm->devices, hw->dev_instance);
    vnet_sw_interface_t * t = (vnet_sw_interface_t *) st;
    int r, vlan_offload;
    u32 prev_subifs = xd->vlan_subifs;
  
    if (is_add) xd->vlan_subifs++;
    else if (xd->vlan_subifs) xd->vlan_subifs--;
  
    if (xd->dev_type != VNET_DPDK_DEV_ETH)
          return 0;
  
    /* currently we program VLANS only for IXGBE VF and I40E VF */
    if ((xd->pmd != VNET_DPDK_PMD_IXGBEVF) &&
        (xd->pmd != VNET_DPDK_PMD_I40EVF))
          return 0;
  
    if (t->sub.eth.flags.no_tags == 1)
          return 0;
  
    if ((t->sub.eth.flags.one_tag != 1) || (t->sub.eth.flags.exact_match != 1 )) {
          xd->vlan_subifs = prev_subifs;
          return clib_error_return (0, "unsupported VLAN setup");
    }
  
    vlan_offload = rte_eth_dev_get_vlan_offload(xd->device_index);
    vlan_offload |= ETH_VLAN_FILTER_OFFLOAD;
  
    if ((r = rte_eth_dev_set_vlan_offload(xd->device_index, vlan_offload))) {
          xd->vlan_subifs = prev_subifs;
          return clib_error_return (0, "rte_eth_dev_set_vlan_offload[%d]: err %d",
                                    xd->device_index, r);
    }
  
  
    if ((r = rte_eth_dev_vlan_filter(xd->device_index, t->sub.eth.outer_vlan_id, is_add))) {
          xd->vlan_subifs = prev_subifs;
          return clib_error_return (0, "rte_eth_dev_vlan_filter[%d]: err %d",
                                   xd->device_index, r);
    }
  
    return 0;
  }
  
  VNET_DEVICE_CLASS (dpdk_device_class) = {
    .name = "dpdk",
    .tx_function = dpdk_interface_tx,
    .tx_function_n_errors = DPDK_TX_FUNC_N_ERROR,
    .tx_function_error_strings = dpdk_tx_func_error_strings,
    .format_device_name = format_dpdk_device_name,
    .format_device = format_dpdk_device,
    .format_tx_trace = format_dpdk_tx_dma_trace,
    .clear_counters = dpdk_clear_hw_interface_counters,
    .admin_up_down_function = dpdk_interface_admin_up_down,
    .subif_add_del_function = dpdk_subif_add_del_function,
    .rx_redirect_to_node = dpdk_set_interface_next_node,
    .no_flatten_output_chains = 1,
    .name_renumber = dpdk_device_renumber,
  };
  
  VLIB_DEVICE_TX_FUNCTION_MULTIARCH (dpdk_device_class,
  				   dpdk_interface_tx)
  
  void dpdk_set_flowcontrol_callback (vlib_main_t *vm, 
                                      dpdk_flowcontrol_callback_t callback)
  {
    dpdk_main.flowcontrol_callback = callback;
  }
  
  #define UP_DOWN_FLAG_EVENT 1
  
  
  u32 dpdk_get_admin_up_down_in_progress (void)
  {
    return dpdk_main.admin_up_down_in_progress;
  }
  
  uword
  admin_up_down_process (vlib_main_t * vm,
                         vlib_node_runtime_t * rt,
                         vlib_frame_t * f)
  {
    clib_error_t * error = 0;
    uword event_type;
    uword *event_data = 0;
    u32 sw_if_index;
    u32 flags;
  
    while (1)  
      { 
        vlib_process_wait_for_event (vm);
  
        event_type = vlib_process_get_events (vm, &event_data);
  
        dpdk_main.admin_up_down_in_progress = 1;
  
        switch (event_type) {
          case UP_DOWN_FLAG_EVENT:
          {
              if (vec_len(event_data) == 2) {
                sw_if_index = event_data[0];
                flags = event_data[1];
                error = vnet_sw_interface_set_flags (vnet_get_main(), sw_if_index, flags);
                clib_error_report(error);
              }
          }
          break;
        }
  
        vec_reset_length (event_data);
  
        dpdk_main.admin_up_down_in_progress = 0;
  
      }
    return 0; /* or not */
  }
  
  VLIB_REGISTER_NODE (admin_up_down_process_node,static) = {
      .function = admin_up_down_process,
      .type = VLIB_NODE_TYPE_PROCESS,
      .name = "admin-up-down-process",
      .process_log2_n_stack_bytes = 17,  // 256KB
  };
  
  /*
   * Asynchronously invoke vnet_sw_interface_set_flags via the admin_up_down 
   * process. Useful for avoiding long blocking delays (>150ms) in the dpdk 
   * drivers.
   * WARNING: when posting this event, no other interface-related calls should
   * be made (e.g. vnet_create_sw_interface()) while the event is being
   * processed (admin_up_down_in_progress). This is required in order to avoid 
   * race conditions in manipulating interface data structures.
   */
  void post_sw_interface_set_flags (vlib_main_t *vm, u32 sw_if_index, u32 flags)
  {
    uword * d = vlib_process_signal_event_data
        (vm, admin_up_down_process_node.index,
         UP_DOWN_FLAG_EVENT, 2, sizeof(u32));
    d[0] = sw_if_index;
    d[1] = flags;
  }
  
  /*
   * Return a copy of the DPDK port stats in dest.
   */
  clib_error_t*
  dpdk_get_hw_interface_stats (u32 hw_if_index, struct rte_eth_stats* dest)
  {
    dpdk_main_t * dm = &dpdk_main;
    vnet_main_t * vnm = vnet_get_main();
    vnet_hw_interface_t * hi = vnet_get_hw_interface (vnm, hw_if_index);
    dpdk_device_t * xd = vec_elt_at_index (dm->devices, hi->dev_instance);
  
    if (!dest) {
       return clib_error_return (0, "Missing or NULL argument");
    }
    if (!xd) {
       return clib_error_return (0, "Unable to get DPDK device from HW interface");
    }
  
    dpdk_update_counters (xd, vlib_time_now (dm->vlib_main));
  
    clib_memcpy(dest, &xd->stats, sizeof(xd->stats));
    return (0);
  }
  
  /*
   * Return the number of dpdk mbufs
   */
  u32 dpdk_num_mbufs (void)
  {
    dpdk_main_t * dm = &dpdk_main;
  
    return dm->conf->num_mbufs;
  }
  
  /*
   * Return the pmd type for a given hardware interface
   */
  dpdk_pmd_t dpdk_get_pmd_type (vnet_hw_interface_t *hi)
  {
    dpdk_main_t   * dm = &dpdk_main;
    dpdk_device_t * xd;
  
    assert (hi);
  
    xd = vec_elt_at_index (dm->devices, hi->dev_instance);
  
    assert (xd);
  
    return xd->pmd;
  }
  
  /*
   * Return the cpu socket for a given hardware interface
   */
  i8 dpdk_get_cpu_socket (vnet_hw_interface_t *hi)
  {
    dpdk_main_t   * dm = &dpdk_main;
    dpdk_device_t * xd;
  
    assert (hi);
  
    xd = vec_elt_at_index(dm->devices, hi->dev_instance);
  
    assert (xd);
  
    return xd->cpu_socket;
  }
  