vhost_user_input.c

Go to the documentation of this file.

/*
 *------------------------------------------------------------------
 * vhost-user-input
 *
 * Copyright (c) 2014-2018 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 <fcntl.h>              /* for open */
#include <sys/ioctl.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/uio.h>            /* for iovec */
#include <netinet/in.h>
#include <sys/vfs.h>

#include <linux/if_arp.h>
#include <linux/if_tun.h>

#include <vlib/vlib.h>
#include <vlib/unix/unix.h>

#include <vnet/ip/ip.h>

#include <vnet/ethernet/ethernet.h>
#include <vnet/devices/devices.h>
#include <vnet/feature/feature.h>

#include <vnet/devices/virtio/vhost_user.h>
#include <vnet/devices/virtio/vhost_user_inline.h>

/*
 * When an RX queue is down but active, received packets
 * must be discarded. This value controls up to how many
 * packets will be discarded during each round.
 */
#define VHOST_USER_DOWN_DISCARD_COUNT 256

/*
 * When the number of available buffers gets under this threshold,
 * RX node will start discarding packets.
 */
#define VHOST_USER_RX_BUFFER_STARVATION 32

/*
 * On the receive side, the host should free descriptors as soon
 * as possible in order to avoid TX drop in the VM.
 * This value controls the number of copy operations that are stacked
 * before copy is done for all and descriptors are given back to
 * the guest.
 * The value 64 was obtained by testing (48 and 128 were not as good).
 */
#define VHOST_USER_RX_COPY_THRESHOLD 64

vlib_node_registration_t vhost_user_input_node;

#define foreach_vhost_user_input_func_error      \
  _(NO_ERROR, "no error")  \
  _(NO_BUFFER, "no available buffer")  \
  _(MMAP_FAIL, "mmap failure")  \
  _(INDIRECT_OVERFLOW, "indirect descriptor overflows table")  \
  _(UNDERSIZED_FRAME, "undersized ethernet frame received (< 14 bytes)") \
  _(FULL_RX_QUEUE, "full rx queue (possible driver tx drop)")

typedef enum
{
#define _(f,s) VHOST_USER_INPUT_FUNC_ERROR_##f,
  foreach_vhost_user_input_func_error
#undef _
    VHOST_USER_INPUT_FUNC_N_ERROR,
} vhost_user_input_func_error_t;

static __clib_unused char *vhost_user_input_func_error_strings[] = {
#define _(n,s) s,
  foreach_vhost_user_input_func_error
#undef _
};

static_always_inline void
vhost_user_rx_trace (vhost_trace_t * t,
                     vhost_user_intf_t * vui, u16 qid,
                     vlib_buffer_t * b, vhost_user_vring_t * txvq)
{
  vhost_user_main_t *vum = &vhost_user_main;
  u32 last_avail_idx = txvq->last_avail_idx;
  u32 desc_current = txvq->avail->ring[last_avail_idx & txvq->qsz_mask];
  vring_desc_t *hdr_desc = 0;
  virtio_net_hdr_mrg_rxbuf_t *hdr;
  u32 hint = 0;

  memset (t, 0, sizeof (*t));
  t->device_index = vui - vum->vhost_user_interfaces;
  t->qid = qid;

  hdr_desc = &txvq->desc[desc_current];
  if (txvq->desc[desc_current].flags & VIRTQ_DESC_F_INDIRECT)
    {
      t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_INDIRECT;
      /* Header is the first here */
      hdr_desc = map_guest_mem (vui, txvq->desc[desc_current].addr, &hint);
    }
  if (txvq->desc[desc_current].flags & VIRTQ_DESC_F_NEXT)
    {
      t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SIMPLE_CHAINED;
    }
  if (!(txvq->desc[desc_current].flags & VIRTQ_DESC_F_NEXT) &&
      !(txvq->desc[desc_current].flags & VIRTQ_DESC_F_INDIRECT))
    {
      t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SINGLE_DESC;
    }

  t->first_desc_len = hdr_desc ? hdr_desc->len : 0;

  if (!hdr_desc || !(hdr = map_guest_mem (vui, hdr_desc->addr, &hint)))
    {
      t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_MAP_ERROR;
    }
  else
    {
      u32 len = vui->virtio_net_hdr_sz;
      memcpy (&t->hdr, hdr, len > hdr_desc->len ? hdr_desc->len : len);
    }
}

static_always_inline u32
vhost_user_input_copy (vhost_user_intf_t * vui, vhost_copy_t * cpy,
                       u16 copy_len, u32 * map_hint)
{
  void *src0, *src1, *src2, *src3;
  if (PREDICT_TRUE (copy_len >= 4))
    {
      if (PREDICT_FALSE (!(src2 = map_guest_mem (vui, cpy[0].src, map_hint))))
        return 1;
      if (PREDICT_FALSE (!(src3 = map_guest_mem (vui, cpy[1].src, map_hint))))
        return 1;

      while (PREDICT_TRUE (copy_len >= 4))
        {
          src0 = src2;
          src1 = src3;

          if (PREDICT_FALSE
              (!(src2 = map_guest_mem (vui, cpy[2].src, map_hint))))
            return 1;
          if (PREDICT_FALSE
              (!(src3 = map_guest_mem (vui, cpy[3].src, map_hint))))
            return 1;

          CLIB_PREFETCH (src2, 64, LOAD);
          CLIB_PREFETCH (src3, 64, LOAD);

          clib_memcpy ((void *) cpy[0].dst, src0, cpy[0].len);
          clib_memcpy ((void *) cpy[1].dst, src1, cpy[1].len);
          copy_len -= 2;
          cpy += 2;
        }
    }
  while (copy_len)
    {
      if (PREDICT_FALSE (!(src0 = map_guest_mem (vui, cpy->src, map_hint))))
        return 1;
      clib_memcpy ((void *) cpy->dst, src0, cpy->len);
      copy_len -= 1;
      cpy += 1;
    }
  return 0;
}

/**
 * Try to discard packets from the tx ring (VPP RX path).
 * Returns the number of discarded packets.
 */
static_always_inline u32
vhost_user_rx_discard_packet (vlib_main_t * vm,
                              vhost_user_intf_t * vui,
                              vhost_user_vring_t * txvq, u32 discard_max)
{
  /*
   * On the RX side, each packet corresponds to one descriptor
   * (it is the same whether it is a shallow descriptor, chained, or indirect).
   * Therefore, discarding a packet is like discarding a descriptor.
   */
  u32 discarded_packets = 0;
  u32 avail_idx = txvq->avail->idx;
  while (discarded_packets != discard_max)
    {
      if (avail_idx == txvq->last_avail_idx)
        goto out;

      u16 desc_chain_head =
        txvq->avail->ring[txvq->last_avail_idx & txvq->qsz_mask];
      txvq->last_avail_idx++;
      txvq->used->ring[txvq->last_used_idx & txvq->qsz_mask].id =
        desc_chain_head;
      txvq->used->ring[txvq->last_used_idx & txvq->qsz_mask].len = 0;
      vhost_user_log_dirty_ring (vui, txvq,
                                 ring[txvq->last_used_idx & txvq->qsz_mask]);
      txvq->last_used_idx++;
      discarded_packets++;
    }

out:
  CLIB_MEMORY_BARRIER ();
  txvq->used->idx = txvq->last_used_idx;
  vhost_user_log_dirty_ring (vui, txvq, idx);
  return discarded_packets;
}

/*
 * In case of overflow, we need to rewind the array of allocated buffers.
 */
static __clib_unused void
vhost_user_input_rewind_buffers (vlib_main_t * vm,
                                 vhost_cpu_t * cpu, vlib_buffer_t * b_head)
{
  u32 bi_current = cpu->rx_buffers[cpu->rx_buffers_len];
  vlib_buffer_t *b_current = vlib_get_buffer (vm, bi_current);
  b_current->current_length = 0;
  b_current->flags = 0;
  while (b_current != b_head)
    {
      cpu->rx_buffers_len++;
      bi_current = cpu->rx_buffers[cpu->rx_buffers_len];
      b_current = vlib_get_buffer (vm, bi_current);
      b_current->current_length = 0;
      b_current->flags = 0;
    }
  cpu->rx_buffers_len++;
}

static __clib_unused u32
vhost_user_if_input (vlib_main_t * vm,
                     vhost_user_main_t * vum,
                     vhost_user_intf_t * vui,
                     u16 qid, vlib_node_runtime_t * node,
                     vnet_hw_interface_rx_mode mode)
{
  vhost_user_vring_t *txvq = &vui->vrings[VHOST_VRING_IDX_TX (qid)];
  u16 n_rx_packets = 0;
  u32 n_rx_bytes = 0;
  u16 n_left;
  u32 n_left_to_next, *to_next;
  u32 next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
  u32 n_trace = vlib_get_trace_count (vm, node);
  u32 map_hint = 0;
  u16 thread_index = vm->thread_index;
  u16 copy_len = 0;

  /* The descriptor table is not ready yet */
  if (PREDICT_FALSE (txvq->avail == 0))
    return 0;

  {
    /* do we have pending interrupts ? */
    vhost_user_vring_t *rxvq = &vui->vrings[VHOST_VRING_IDX_RX (qid)];
    f64 now = vlib_time_now (vm);

    if ((txvq->n_since_last_int) && (txvq->int_deadline < now))
      vhost_user_send_call (vm, txvq);

    if ((rxvq->n_since_last_int) && (rxvq->int_deadline < now))
      vhost_user_send_call (vm, rxvq);
  }

  /*
   * For adaptive mode, it is optimized to reduce interrupts.
   * If the scheduler switches the input node to polling due
   * to burst of traffic, we tell the driver no interrupt.
   * When the traffic subsides, the scheduler switches the node back to
   * interrupt mode. We must tell the driver we want interrupt.
   */
  if (PREDICT_FALSE (mode == VNET_HW_INTERFACE_RX_MODE_ADAPTIVE))
    {
      if ((node->flags &
           VLIB_NODE_FLAG_SWITCH_FROM_POLLING_TO_INTERRUPT_MODE) ||
          !(node->flags &
            VLIB_NODE_FLAG_SWITCH_FROM_INTERRUPT_TO_POLLING_MODE))
        /* Tell driver we want notification */
        txvq->used->flags = 0;
      else
        /* Tell driver we don't want notification */
        txvq->used->flags = VRING_USED_F_NO_NOTIFY;
    }

  if (PREDICT_FALSE (txvq->avail->flags & 0xFFFE))
    return 0;

  n_left = (u16) (txvq->avail->idx - txvq->last_avail_idx);

  /* nothing to do */
  if (PREDICT_FALSE (n_left == 0))
    return 0;

  if (PREDICT_FALSE (!vui->admin_up || !(txvq->enabled)))
    {
      /*
       * Discard input packet if interface is admin down or vring is not
       * enabled.
       * "For example, for a networking device, in the disabled state
       * client must not supply any new RX packets, but must process
       * and discard any TX packets."
       */
      vhost_user_rx_discard_packet (vm, vui, txvq,
                                    VHOST_USER_DOWN_DISCARD_COUNT);
      return 0;
    }

  if (PREDICT_FALSE (n_left == (txvq->qsz_mask + 1)))
    {
      /*
       * Informational error logging when VPP is not
       * receiving packets fast enough.
       */
      vlib_error_count (vm, node->node_index,
                        VHOST_USER_INPUT_FUNC_ERROR_FULL_RX_QUEUE, 1);
    }

  if (n_left > VLIB_FRAME_SIZE)
    n_left = VLIB_FRAME_SIZE;

  /*
   * For small packets (<2kB), we will not need more than one vlib buffer
   * per packet. In case packets are bigger, we will just yeld at some point
   * in the loop and come back later. This is not an issue as for big packet,
   * processing cost really comes from the memory copy.
   * The assumption is that big packets will fit in 40 buffers.
   */
  if (PREDICT_FALSE (vum->cpus[thread_index].rx_buffers_len < n_left + 1 ||
                     vum->cpus[thread_index].rx_buffers_len < 40))
    {
      u32 curr_len = vum->cpus[thread_index].rx_buffers_len;
      vum->cpus[thread_index].rx_buffers_len +=
        vlib_buffer_alloc_from_free_list (vm,
                                          vum->cpus[thread_index].rx_buffers +
                                          curr_len,
                                          VHOST_USER_RX_BUFFERS_N - curr_len,
                                          VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);

      if (PREDICT_FALSE
          (vum->cpus[thread_index].rx_buffers_len <
           VHOST_USER_RX_BUFFER_STARVATION))
        {
          /* In case of buffer starvation, discard some packets from the queue
           * and log the event.
           * We keep doing best effort for the remaining packets. */
          u32 flush = (n_left + 1 > vum->cpus[thread_index].rx_buffers_len) ?
            n_left + 1 - vum->cpus[thread_index].rx_buffers_len : 1;
          flush = vhost_user_rx_discard_packet (vm, vui, txvq, flush);

          n_left -= flush;
          vlib_increment_simple_counter (vnet_main.
                                         interface_main.sw_if_counters +
                                         VNET_INTERFACE_COUNTER_DROP,
                                         vlib_get_thread_index (),
                                         vui->sw_if_index, flush);

          vlib_error_count (vm, vhost_user_input_node.index,
                            VHOST_USER_INPUT_FUNC_ERROR_NO_BUFFER, flush);
        }
    }

  while (n_left > 0)
    {
      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      while (n_left > 0 && n_left_to_next > 0)
        {
          vlib_buffer_t *b_head, *b_current;
          u32 bi_current;
          u16 desc_current;
          u32 desc_data_offset;
          vring_desc_t *desc_table = txvq->desc;

          if (PREDICT_FALSE (vum->cpus[thread_index].rx_buffers_len <= 1))
            {
              /* Not enough rx_buffers
               * Note: We yeld on 1 so we don't need to do an additional
               * check for the next buffer prefetch.
               */
              n_left = 0;
              break;
            }

          desc_current =
            txvq->avail->ring[txvq->last_avail_idx & txvq->qsz_mask];
          vum->cpus[thread_index].rx_buffers_len--;
          bi_current = (vum->cpus[thread_index].rx_buffers)
            [vum->cpus[thread_index].rx_buffers_len];
          b_head = b_current = vlib_get_buffer (vm, bi_current);
          to_next[0] = bi_current;      //We do that now so we can forget about bi_current
          to_next++;
          n_left_to_next--;

          vlib_prefetch_buffer_with_index (vm,
                                           (vum->
                                            cpus[thread_index].rx_buffers)
                                           [vum->cpus[thread_index].
                                            rx_buffers_len - 1], LOAD);

          /* Just preset the used descriptor id and length for later */
          txvq->used->ring[txvq->last_used_idx & txvq->qsz_mask].id =
            desc_current;
          txvq->used->ring[txvq->last_used_idx & txvq->qsz_mask].len = 0;
          vhost_user_log_dirty_ring (vui, txvq,
                                     ring[txvq->last_used_idx &
                                          txvq->qsz_mask]);

          /* The buffer should already be initialized */
          b_head->total_length_not_including_first_buffer = 0;
          b_head->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;

          if (PREDICT_FALSE (n_trace))
            {
              //TODO: next_index is not exactly known at that point
              vlib_trace_buffer (vm, node, next_index, b_head,
                                 /* follow_chain */ 0);
              vhost_trace_t *t0 =
                vlib_add_trace (vm, node, b_head, sizeof (t0[0]));
              vhost_user_rx_trace (t0, vui, qid, b_head, txvq);
              n_trace--;
              vlib_set_trace_count (vm, node, n_trace);
            }

          /* This depends on the setup but is very consistent
           * So I think the CPU branch predictor will make a pretty good job
           * at optimizing the decision. */
          if (txvq->desc[desc_current].flags & VIRTQ_DESC_F_INDIRECT)
            {
              desc_table = map_guest_mem (vui, txvq->desc[desc_current].addr,
                                          &map_hint);
              desc_current = 0;
              if (PREDICT_FALSE (desc_table == 0))
                {
                  vlib_error_count (vm, node->node_index,
                                    VHOST_USER_INPUT_FUNC_ERROR_MMAP_FAIL, 1);
                  goto out;
                }
            }

          if (PREDICT_TRUE (vui->is_any_layout) ||
              (!(desc_table[desc_current].flags & VIRTQ_DESC_F_NEXT)))
            {
              /* ANYLAYOUT or single buffer */
              desc_data_offset = vui->virtio_net_hdr_sz;
            }
          else
            {
              /* CSR case without ANYLAYOUT, skip 1st buffer */
              desc_data_offset = desc_table[desc_current].len;
            }

          while (1)
            {
              /* Get more input if necessary. Or end of packet. */
              if (desc_data_offset == desc_table[desc_current].len)
                {
                  if (PREDICT_FALSE (desc_table[desc_current].flags &
                                     VIRTQ_DESC_F_NEXT))
                    {
                      desc_current = desc_table[desc_current].next;
                      desc_data_offset = 0;
                    }
                  else
                    {
                      goto out;
                    }
                }

              /* Get more output if necessary. Or end of packet. */
              if (PREDICT_FALSE
                  (b_current->current_length == VLIB_BUFFER_DATA_SIZE))
                {
                  if (PREDICT_FALSE
                      (vum->cpus[thread_index].rx_buffers_len == 0))
                    {
                      /* Cancel speculation */
                      to_next--;
                      n_left_to_next++;

                      /*
                       * Checking if there are some left buffers.
                       * If not, just rewind the used buffers and stop.
                       * Note: Scheduled copies are not cancelled. This is
                       * not an issue as they would still be valid. Useless,
                       * but valid.
                       */
                      vhost_user_input_rewind_buffers (vm,
                                                       &vum->cpus
                                                       [thread_index],
                                                       b_head);
                      n_left = 0;
                      goto stop;
                    }

                  /* Get next output */
                  vum->cpus[thread_index].rx_buffers_len--;
                  u32 bi_next =
                    (vum->cpus[thread_index].rx_buffers)[vum->cpus
                                                         [thread_index].rx_buffers_len];
                  b_current->next_buffer = bi_next;
                  b_current->flags |= VLIB_BUFFER_NEXT_PRESENT;
                  bi_current = bi_next;
                  b_current = vlib_get_buffer (vm, bi_current);
                }

              /* Prepare a copy order executed later for the data */
              vhost_copy_t *cpy = &vum->cpus[thread_index].copy[copy_len];
              copy_len++;
              u32 desc_data_l =
                desc_table[desc_current].len - desc_data_offset;
              cpy->len = VLIB_BUFFER_DATA_SIZE - b_current->current_length;
              cpy->len = (cpy->len > desc_data_l) ? desc_data_l : cpy->len;
              cpy->dst = (uword) (vlib_buffer_get_current (b_current) +
                                  b_current->current_length);
              cpy->src = desc_table[desc_current].addr + desc_data_offset;

              desc_data_offset += cpy->len;

              b_current->current_length += cpy->len;
              b_head->total_length_not_including_first_buffer += cpy->len;
            }

        out:
          CLIB_PREFETCH (&n_left, sizeof (n_left), LOAD);

          n_rx_bytes += b_head->total_length_not_including_first_buffer;
          n_rx_packets++;

          b_head->total_length_not_including_first_buffer -=
            b_head->current_length;

          /* consume the descriptor and return it as used */
          txvq->last_avail_idx++;
          txvq->last_used_idx++;

          VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b_head);

          vnet_buffer (b_head)->sw_if_index[VLIB_RX] = vui->sw_if_index;
          vnet_buffer (b_head)->sw_if_index[VLIB_TX] = (u32) ~ 0;
          b_head->error = 0;

          {
            u32 next0 = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;

            /* redirect if feature path enabled */
            vnet_feature_start_device_input_x1 (vui->sw_if_index, &next0,
                                                b_head);

            u32 bi = to_next[-1];       //Cannot use to_next[-1] in the macro
            vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
                                             to_next, n_left_to_next,
                                             bi, next0);
          }

          n_left--;

          /*
           * Although separating memory copies from virtio ring parsing
           * is beneficial, we can offer to perform the copies from time
           * to time in order to free some space in the ring.
           */
          if (PREDICT_FALSE (copy_len >= VHOST_USER_RX_COPY_THRESHOLD))
            {
              if (PREDICT_FALSE
                  (vhost_user_input_copy (vui, vum->cpus[thread_index].copy,
                                          copy_len, &map_hint)))
                {
                  vlib_error_count (vm, node->node_index,
                                    VHOST_USER_INPUT_FUNC_ERROR_MMAP_FAIL, 1);
                }
              copy_len = 0;

              /* give buffers back to driver */
              CLIB_MEMORY_BARRIER ();
              txvq->used->idx = txvq->last_used_idx;
              vhost_user_log_dirty_ring (vui, txvq, idx);
            }
        }
    stop:
      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }

  /* Do the memory copies */
  if (PREDICT_FALSE
      (vhost_user_input_copy (vui, vum->cpus[thread_index].copy,
                              copy_len, &map_hint)))
    {
      vlib_error_count (vm, node->node_index,
                        VHOST_USER_INPUT_FUNC_ERROR_MMAP_FAIL, 1);
    }

  /* give buffers back to driver */
  CLIB_MEMORY_BARRIER ();
  txvq->used->idx = txvq->last_used_idx;
  vhost_user_log_dirty_ring (vui, txvq, idx);

  /* interrupt (call) handling */
  if ((txvq->callfd_idx != ~0) &&
      !(txvq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
    {
      txvq->n_since_last_int += n_rx_packets;

      if (txvq->n_since_last_int > vum->coalesce_frames)
        vhost_user_send_call (vm, txvq);
    }

  /* increase rx counters */
  vlib_increment_combined_counter
    (vnet_main.interface_main.combined_sw_if_counters
     + VNET_INTERFACE_COUNTER_RX,
     vlib_get_thread_index (), vui->sw_if_index, n_rx_packets, n_rx_bytes);

  vnet_device_increment_rx_packets (thread_index, n_rx_packets);

  return n_rx_packets;
}

VLIB_NODE_FN (vhost_user_input_node) (vlib_main_t * vm,
                                      vlib_node_runtime_t * node,
                                      vlib_frame_t * frame)
{
  vhost_user_main_t *vum = &vhost_user_main;
  uword n_rx_packets = 0;
  vhost_user_intf_t *vui;
  vnet_device_input_runtime_t *rt =
    (vnet_device_input_runtime_t *) node->runtime_data;
  vnet_device_and_queue_t *dq;

  vec_foreach (dq, rt->devices_and_queues)
  {
    if (clib_smp_swap (&dq->interrupt_pending, 0) ||
        (node->state == VLIB_NODE_STATE_POLLING))
      {
        vui =
          pool_elt_at_index (vum->vhost_user_interfaces, dq->dev_instance);
        n_rx_packets = vhost_user_if_input (vm, vum, vui, dq->queue_id, node,
                                            dq->mode);
      }
  }

  return n_rx_packets;
}

#ifndef CLIB_MARCH_VARIANT
/* *INDENT-OFF* */
VLIB_REGISTER_NODE (vhost_user_input_node) = {
  .type = VLIB_NODE_TYPE_INPUT,
  .name = "vhost-user-input",
  .sibling_of = "device-input",

  /* Will be enabled if/when hardware is detected. */
  .state = VLIB_NODE_STATE_DISABLED,

  .format_buffer = format_ethernet_header_with_length,
  .format_trace = format_vhost_trace,

  .n_errors = VHOST_USER_INPUT_FUNC_N_ERROR,
  .error_strings = vhost_user_input_func_error_strings,
};
/* *INDENT-ON* */
#endif

/*
 * fd.io coding-style-patch-verification: ON
 *
 * Local Variables:
 * eval: (c-set-style "gnu")
 * End:
 */