src/vnet/devices/virtio/virtio.c - fdio/vpp - Gitiles

 /*
  *------------------------------------------------------------------
  * Copyright (c) 2017 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 <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <net/if.h>
 #include <linux/if_tun.h>
 #include <sys/ioctl.h>
 #include <sys/eventfd.h>

 #include <vlib/vlib.h>
 #include <vlib/pci/pci.h>
 #include <vlib/unix/unix.h>
 #include <vnet/ethernet/ethernet.h>
 #include <vnet/ip/ip4_packet.h>
 #include <vnet/ip/ip6_packet.h>
 #include <vnet/devices/virtio/virtio.h>
 #include <vnet/devices/virtio/virtio_inline.h>
 #include <vnet/devices/virtio/pci.h>
 #include <vnet/interface/rx_queue_funcs.h>
 #include <vnet/interface/tx_queue_funcs.h>

 virtio_main_t virtio_main;

 #define _IOCTL(fd,a,...) \
   if (ioctl (fd, a, __VA_ARGS__) < 0) \
     { \
       err = clib_error_return_unix (0, "ioctl(" #a ")"); \
       goto error; \
     }

 static clib_error_t *
 call_read_ready (clib_file_t * uf)
 {
   vnet_main_t *vnm = vnet_get_main ();
   u64 b;

   CLIB_UNUSED (ssize_t size) = read (uf->file_descriptor, &b, sizeof (b));
   vnet_hw_if_rx_queue_set_int_pending (vnm, uf->private_data);

   return 0;
 }


 clib_error_t *
 virtio_vring_init (vlib_main_t * vm, virtio_if_t * vif, u16 idx, u16 sz)
 {
   virtio_vring_t *vring;
   int i;

   if (!is_pow2 (sz))
     return clib_error_return (0, "ring size must be power of 2");

   if (sz > 32768)
     return clib_error_return (0, "ring size must be 32768 or lower");

   if (sz == 0)
     sz = 256;

   if (idx % 2)
     {
       vec_validate_aligned (vif->txq_vrings, TX_QUEUE_ACCESS (idx),
 			    CLIB_CACHE_LINE_BYTES);
       vring = vec_elt_at_index (vif->txq_vrings, TX_QUEUE_ACCESS (idx));
       clib_spinlock_init (&vring->lockp);
     }
   else
     {
       vec_validate_aligned (vif->rxq_vrings, RX_QUEUE_ACCESS (idx),
 			    CLIB_CACHE_LINE_BYTES);
       vring = vec_elt_at_index (vif->rxq_vrings, RX_QUEUE_ACCESS (idx));
     }
   i = sizeof (vring_desc_t) * sz;
   i = round_pow2 (i, CLIB_CACHE_LINE_BYTES);
   vring->desc = clib_mem_alloc_aligned (i, CLIB_CACHE_LINE_BYTES);
   clib_memset (vring->desc, 0, i);

   i = sizeof (vring_avail_t) + sz * sizeof (vring->avail->ring[0]);
   i = round_pow2 (i, CLIB_CACHE_LINE_BYTES);
   vring->avail = clib_mem_alloc_aligned (i, CLIB_CACHE_LINE_BYTES);
   clib_memset (vring->avail, 0, i);
   // tell kernel that we don't need interrupt
   vring->avail->flags = VRING_AVAIL_F_NO_INTERRUPT;

   i = sizeof (vring_used_t) + sz * sizeof (vring_used_elem_t);
   i = round_pow2 (i, CLIB_CACHE_LINE_BYTES);
   vring->used = clib_mem_alloc_aligned (i, CLIB_CACHE_LINE_BYTES);
   clib_memset (vring->used, 0, i);

   vring->queue_id = idx;
   ASSERT (vring->buffers == 0);
   vec_validate_aligned (vring->buffers, sz, CLIB_CACHE_LINE_BYTES);

   if (idx & 1)
     {
       clib_memset_u32 (vring->buffers, ~0, sz);
       // tx path: suppress the interrupts from kernel
       vring->call_fd = -1;
     }
   else
     vring->call_fd = eventfd (0, EFD_NONBLOCK | EFD_CLOEXEC);

   vring->size = sz;
   vring->kick_fd = eventfd (0, EFD_NONBLOCK | EFD_CLOEXEC);
   virtio_log_debug (vif, "vring %u size %u call_fd %d kick_fd %d", idx,
 		    vring->size, vring->call_fd, vring->kick_fd);

   return 0;
 }

 inline void
 virtio_free_buffers (vlib_main_t * vm, virtio_vring_t * vring)
 {
   u16 used = vring->desc_in_use;
   u16 last = vring->last_used_idx;
   u16 mask = vring->size - 1;

   while (used)
     {
       vlib_buffer_free (vm, &vring->buffers[last & mask], 1);
       last++;
       used--;
     }
 }

 clib_error_t *
 virtio_vring_free_rx (vlib_main_t * vm, virtio_if_t * vif, u32 idx)
 {
   virtio_vring_t *vring =
     vec_elt_at_index (vif->rxq_vrings, RX_QUEUE_ACCESS (idx));

   clib_file_del_by_index (&file_main, vring->call_file_index);
   close (vring->kick_fd);
   close (vring->call_fd);
   if (vring->used)
     {
       virtio_free_buffers (vm, vring);
       clib_mem_free (vring->used);
     }
   if (vring->desc)
     clib_mem_free (vring->desc);
   if (vring->avail)
     clib_mem_free (vring->avail);
   vec_free (vring->buffers);
   return 0;
 }

 clib_error_t *
 virtio_vring_free_tx (vlib_main_t * vm, virtio_if_t * vif, u32 idx)
 {
   virtio_vring_t *vring =
     vec_elt_at_index (vif->txq_vrings, TX_QUEUE_ACCESS (idx));

   close (vring->kick_fd);
   if (vring->used)
     {
       virtio_free_buffers (vm, vring);
       clib_mem_free (vring->used);
     }
   if (vring->desc)
     clib_mem_free (vring->desc);
   if (vring->avail)
     clib_mem_free (vring->avail);
   vec_free (vring->buffers);
   gro_flow_table_free (vring->flow_table);
   virtio_vring_buffering_free (vm, vring->buffering);
   clib_spinlock_free (&vring->lockp);
   return 0;
 }

 void
 virtio_set_packet_coalesce (virtio_if_t * vif)
 {
   vnet_main_t *vnm = vnet_get_main ();
   vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, vif->hw_if_index);
   virtio_vring_t *vring;
   vif->packet_coalesce = 1;
   vec_foreach (vring, vif->txq_vrings)
   {
     gro_flow_table_init (&vring->flow_table,
 			 vif->type & (VIRTIO_IF_TYPE_TAP |
 				      VIRTIO_IF_TYPE_PCI), hw->tx_node_index);
   }
 }

 clib_error_t *
 virtio_set_packet_buffering (virtio_if_t * vif, u16 buffering_size)
 {
   vnet_main_t *vnm = vnet_get_main ();
   vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, vif->hw_if_index);
   virtio_vring_t *vring;
   clib_error_t *error = 0;
   vif->packet_buffering = 1;

   vec_foreach (vring, vif->txq_vrings)
   {
     if ((error =
 	 virtio_vring_buffering_init (&vring->buffering, hw->tx_node_index,
 				      buffering_size)))
       {
 	break;
       }
   }

   return error;
 }

 static void
 virtio_vring_fill (vlib_main_t *vm, virtio_if_t *vif, virtio_vring_t *vring)
 {
   if (vif->is_packed)
     virtio_refill_vring_packed (vm, vif, vif->type, vring,
 				vif->virtio_net_hdr_sz,
 				virtio_input_node.index);
   else
     virtio_refill_vring_split (vm, vif, vif->type, vring,
 			       vif->virtio_net_hdr_sz,
 			       virtio_input_node.index);
 }

 void
 virtio_vring_set_rx_queues (vlib_main_t *vm, virtio_if_t *vif)
 {
   vnet_main_t *vnm = vnet_get_main ();
   virtio_vring_t *vring;
   u32 i = 0;

   vnet_hw_if_set_input_node (vnm, vif->hw_if_index, virtio_input_node.index);

   vec_foreach (vring, vif->rxq_vrings)
     {
       vring->queue_index = vnet_hw_if_register_rx_queue (
 	vnm, vif->hw_if_index, RX_QUEUE_ACCESS (vring->queue_id),
 	VNET_HW_IF_RXQ_THREAD_ANY);
       vring->buffer_pool_index = vlib_buffer_pool_get_default_for_numa (
 	vm, vnet_hw_if_get_rx_queue_numa_node (vnm, vring->queue_index));
       if (vif->type == VIRTIO_IF_TYPE_TAP || vif->type == VIRTIO_IF_TYPE_TUN)
 	{

 	  clib_file_t f = {
 	    .read_function = call_read_ready,
 	    .flags = UNIX_FILE_EVENT_EDGE_TRIGGERED,
 	    .file_descriptor = vring->call_fd,
 	    .private_data = vring->queue_index,
 	    .description = format (0, "%U vring %u", format_virtio_device_name,
 				   vif->dev_instance, vring->queue_id),
 	  };

 	  vring->call_file_index = clib_file_add (&file_main, &f);
 	  vnet_hw_if_set_rx_queue_file_index (vnm, vring->queue_index,
 					      vring->call_file_index);
 	}
       else if ((vif->type == VIRTIO_IF_TYPE_PCI) && (vif->support_int_mode) &&
 	       (vif->msix_enabled == VIRTIO_MSIX_ENABLED))
 	{
 	  u32 file_index;
 	  file_index =
 	    vlib_pci_get_msix_file_index (vm, vif->pci_dev_handle, i + 1);
 	  vnet_hw_if_set_rx_queue_file_index (vnm, vring->queue_index,
 					      file_index);
 	  i++;
 	}
       vnet_hw_if_set_rx_queue_mode (vnm, vring->queue_index,
 				    VNET_HW_IF_RX_MODE_POLLING);
       vring->mode = VNET_HW_IF_RX_MODE_POLLING;
       virtio_vring_fill (vm, vif, vring);
     }
   vnet_hw_if_update_runtime_data (vnm, vif->hw_if_index);
 }

 void
 virtio_vring_set_tx_queues (vlib_main_t *vm, virtio_if_t *vif)
 {
   vnet_main_t *vnm = vnet_get_main ();
   virtio_vring_t *vring;

   vec_foreach (vring, vif->txq_vrings)
     {
       vring->queue_index = vnet_hw_if_register_tx_queue (
 	vnm, vif->hw_if_index, TX_QUEUE_ACCESS (vring->queue_id));
     }

   if (vif->num_txqs == 0)
     {
       virtio_log_error (vif, "Interface %U has 0 txq",
 			format_vnet_hw_if_index_name, vnm, vif->hw_if_index);
       return;
     }

   for (u32 j = 0; j < vlib_get_n_threads (); j++)
     {
       u32 qi = vif->txq_vrings[j % vif->num_txqs].queue_index;
       vnet_hw_if_tx_queue_assign_thread (vnm, qi, j);
     }

   vnet_hw_if_update_runtime_data (vnm, vif->hw_if_index);
 }

 inline void
 virtio_set_net_hdr_size (virtio_if_t * vif)
 {
   if (vif->features & VIRTIO_FEATURE (VIRTIO_NET_F_MRG_RXBUF) ||
       vif->features & VIRTIO_FEATURE (VIRTIO_F_VERSION_1))
     vif->virtio_net_hdr_sz = sizeof (virtio_net_hdr_v1_t);
   else
     vif->virtio_net_hdr_sz = sizeof (virtio_net_hdr_t);
 }

 inline void
 virtio_show (vlib_main_t *vm, u32 *hw_if_indices, u8 show_descr,
 	     virtio_if_type_t type)
 {
   u32 i, j, hw_if_index;
   virtio_if_t *vif;
   vnet_main_t *vnm = &vnet_main;
   virtio_main_t *mm = &virtio_main;
   virtio_vring_t *vring;
   struct feat_struct
   {
     u8 bit;
     char *str;
   };
   struct feat_struct *feat_entry;

   static struct feat_struct feat_array[] = {
 #define _(s,b) { .str = #s, .bit = b, },
     foreach_virtio_net_features
 #undef _
     {.str = NULL}
   };

   struct feat_struct *flag_entry;
   static struct feat_struct flags_array[] = {
 #define _(b,e,s) { .bit = b, .str = s, },
     foreach_virtio_if_flag
 #undef _
     {.str = NULL}
   };

   if (!hw_if_indices)
     return;

   for (hw_if_index = 0; hw_if_index < vec_len (hw_if_indices); hw_if_index++)
     {
       vnet_hw_interface_t *hi =
 	vnet_get_hw_interface (vnm, hw_if_indices[hw_if_index]);
       vif = pool_elt_at_index (mm->interfaces, hi->dev_instance);
       if (vif->type != type)
 	continue;
       vlib_cli_output (vm, "Interface: %U (ifindex %d)",
 		       format_vnet_hw_if_index_name, vnm,
 		       hw_if_indices[hw_if_index], vif->hw_if_index);
       if (type == VIRTIO_IF_TYPE_PCI)
 	{
 	  vlib_cli_output (vm, "  PCI Address: %U", format_vlib_pci_addr,
 			   &vif->pci_addr);
 	}
       if (type & (VIRTIO_IF_TYPE_TAP | VIRTIO_IF_TYPE_TUN))
 	{
 	  u8 *str = 0;
 	  if (vif->host_if_name)
 	    vlib_cli_output (vm, "  name \"%s\"", vif->host_if_name);
 	  if (vif->net_ns)
 	    vlib_cli_output (vm, "  host-ns \"%s\"", vif->net_ns);
 	  if (vif->host_mtu_size)
 	    vlib_cli_output (vm, "  host-mtu-size \"%d\"",
 			     vif->host_mtu_size);
 	  if (type == VIRTIO_IF_TYPE_TAP)
 	    vlib_cli_output (vm, "  host-mac-addr: %U",
 			     format_ethernet_address, vif->host_mac_addr);
 	  vlib_cli_output (vm, "  host-carrier-up: %u", vif->host_carrier_up);

 	  vec_foreach_index (i, vif->vhost_fds)
 	    str = format (str, " %d", vif->vhost_fds[i]);
 	  vlib_cli_output (vm, "  vhost-fds%v", str);
 	  vec_free (str);
 	  vec_foreach_index (i, vif->tap_fds)
 	    str = format (str, " %d", vif->tap_fds[i]);
 	  vlib_cli_output (vm, "  tap-fds%v", str);
 	  vec_free (str);
 	}
       vlib_cli_output (vm, "  gso-enabled %d", vif->gso_enabled);
       vlib_cli_output (vm, "  csum-enabled %d", vif->csum_offload_enabled);
       vlib_cli_output (vm, "  packet-coalesce %d", vif->packet_coalesce);
       vlib_cli_output (vm, "  packet-buffering %d", vif->packet_buffering);
       if (type & (VIRTIO_IF_TYPE_TAP | VIRTIO_IF_TYPE_PCI))
 	vlib_cli_output (vm, "  Mac Address: %U", format_ethernet_address,
 			 vif->mac_addr);
       vlib_cli_output (vm, "  Device instance: %u", vif->dev_instance);
       vlib_cli_output (vm, "  flags 0x%x", vif->flags);
       flag_entry = (struct feat_struct *) &flags_array;
       while (flag_entry->str)
 	{
 	  if (vif->flags & (1ULL << flag_entry->bit))
 	    vlib_cli_output (vm, "    %s (%d)", flag_entry->str,
 			     flag_entry->bit);
 	  flag_entry++;
 	}
       if (type == VIRTIO_IF_TYPE_PCI)
 	{
 	  device_status (vm, vif);
 	}
       vlib_cli_output (vm, "  features 0x%lx", vif->features);
       feat_entry = (struct feat_struct *) &feat_array;
       while (feat_entry->str)
 	{
 	  if (vif->features & (1ULL << feat_entry->bit))
 	    vlib_cli_output (vm, "    %s (%d)", feat_entry->str,
 			     feat_entry->bit);
 	  feat_entry++;
 	}
       vlib_cli_output (vm, "  remote-features 0x%lx", vif->remote_features);
       feat_entry = (struct feat_struct *) &feat_array;
       while (feat_entry->str)
 	{
 	  if (vif->remote_features & (1ULL << feat_entry->bit))
 	    vlib_cli_output (vm, "    %s (%d)", feat_entry->str,
 			     feat_entry->bit);
 	  feat_entry++;
 	}
       vlib_cli_output (vm, "  Number of RX Virtqueue  %u", vif->num_rxqs);
       vlib_cli_output (vm, "  Number of TX Virtqueue  %u", vif->num_txqs);
       if (type == VIRTIO_IF_TYPE_PCI && vif->cxq_vring != NULL &&
 	  vif->features & VIRTIO_FEATURE (VIRTIO_NET_F_CTRL_VQ))
 	vlib_cli_output (vm, "  Number of CTRL Virtqueue 1");
       vec_foreach_index (i, vif->rxq_vrings)
       {
 	vring = vec_elt_at_index (vif->rxq_vrings, i);
 	vlib_cli_output (vm, "  Virtqueue (RX) %d", vring->queue_id);
 	vlib_cli_output (vm,
 			 "    qsz %d, last_used_idx %d, desc_next %d, desc_in_use %d",
 			 vring->size, vring->last_used_idx, vring->desc_next,
 			 vring->desc_in_use);
 	if (vif->is_packed)
 	  {
 	    vlib_cli_output (vm,
 			     "    driver_event.flags 0x%x driver_event.off_wrap %d device_event.flags 0x%x device_event.off_wrap %d",
 			     vring->driver_event->flags,
 			     vring->driver_event->off_wrap,
 			     vring->device_event->flags,
 			     vring->device_event->off_wrap);
 	    vlib_cli_output (vm,
 			     "    avail wrap counter %d, used wrap counter %d",
 			     vring->avail_wrap_counter,
 			     vring->used_wrap_counter);
 	  }
 	else
 	  vlib_cli_output (vm,
 			   "    avail.flags 0x%x avail.idx %d used.flags 0x%x used.idx %d",
 			   vring->avail->flags, vring->avail->idx,
 			   vring->used->flags, vring->used->idx);
 	if (type & (VIRTIO_IF_TYPE_TAP | VIRTIO_IF_TYPE_TUN))
 	  {
 	    vlib_cli_output (vm, "    kickfd %d, callfd %d", vring->kick_fd,
 			     vring->call_fd);
 	  }
 	if (show_descr)
 	  {
 	    vlib_cli_output (vm, "\n  descriptor table:\n");
 	    vlib_cli_output (vm,
 			     "   id          addr         len  flags  next/id      user_addr\n");
 	    vlib_cli_output (vm,
 			     "  ===== ================== ===== ====== ======= ==================\n");
 	    for (j = 0; j < vring->size; j++)
 	      {
 		if (vif->is_packed)
 		  {
 		    vring_packed_desc_t *desc = &vring->packed_desc[j];
 		    vlib_cli_output (vm,
 				     "  %-5d 0x%016lx %-5d 0x%04x %-8d 0x%016lx\n",
 				     j, desc->addr,
 				     desc->len,
 				     desc->flags, desc->id, desc->addr);
 		  }
 		else
 		  {
 		    vring_desc_t *desc = &vring->desc[j];
 		    vlib_cli_output (vm,
 				     "  %-5d 0x%016lx %-5d 0x%04x %-8d 0x%016lx\n",
 				     j, desc->addr,
 				     desc->len,
 				     desc->flags, desc->next, desc->addr);
 		  }
 	      }
 	  }
       }
       vec_foreach_index (i, vif->txq_vrings)
       {
 	vring = vec_elt_at_index (vif->txq_vrings, i);
 	vlib_cli_output (vm, "  Virtqueue (TX) %d", vring->queue_id);
 	vlib_cli_output (vm,
 			 "    qsz %d, last_used_idx %d, desc_next %d, desc_in_use %d",
 			 vring->size, vring->last_used_idx, vring->desc_next,
 			 vring->desc_in_use);
 	if (vif->is_packed)
 	  {
 	    vlib_cli_output (vm,
 			     "    driver_event.flags 0x%x driver_event.off_wrap %d device_event.flags 0x%x device_event.off_wrap %d",
 			     vring->driver_event->flags,
 			     vring->driver_event->off_wrap,
 			     vring->device_event->flags,
 			     vring->device_event->off_wrap);
 	    vlib_cli_output (vm,
 			     "    avail wrap counter %d, used wrap counter %d",
 			     vring->avail_wrap_counter,
 			     vring->used_wrap_counter);
 	  }
 	else
 	  vlib_cli_output (vm,
 			   "    avail.flags 0x%x avail.idx %d used.flags 0x%x used.idx %d",
 			   vring->avail->flags, vring->avail->idx,
 			   vring->used->flags, vring->used->idx);
 	if (type & (VIRTIO_IF_TYPE_TAP | VIRTIO_IF_TYPE_TUN))
 	  {
 	    vlib_cli_output (vm, "    kickfd %d, callfd %d", vring->kick_fd,
 			     vring->call_fd);
 	  }
 	if (vring->flow_table)
 	  {
 	    vlib_cli_output (vm, "    %U", gro_flow_table_format,
 			     vring->flow_table);
 	  }
 	if (vif->packet_buffering)
 	  {
 	    vlib_cli_output (vm, "    %U", virtio_vring_buffering_format,
 			     vring->buffering);
 	  }
 	if (show_descr)
 	  {
 	    vlib_cli_output (vm, "\n  descriptor table:\n");
 	    vlib_cli_output (vm,
 			     "   id          addr         len  flags  next/id      user_addr\n");
 	    vlib_cli_output (vm,
 			     "  ===== ================== ===== ====== ======== ==================\n");
 	    for (j = 0; j < vring->size; j++)
 	      {
 		if (vif->is_packed)
 		  {
 		    vring_packed_desc_t *desc = &vring->packed_desc[j];
 		    vlib_cli_output (vm,
 				     "  %-5d 0x%016lx %-5d 0x%04x %-8d 0x%016lx\n",
 				     j, desc->addr,
 				     desc->len,
 				     desc->flags, desc->id, desc->addr);
 		  }
 		else
 		  {
 		    vring_desc_t *desc = &vring->desc[j];
 		    vlib_cli_output (vm,
 				     "  %-5d 0x%016lx %-5d 0x%04x %-8d 0x%016lx\n",
 				     j, desc->addr,
 				     desc->len,
 				     desc->flags, desc->next, desc->addr);
 		  }
 	      }
 	  }
       }
       if (type == VIRTIO_IF_TYPE_PCI && vif->cxq_vring != NULL &&
 	  vif->features & VIRTIO_FEATURE (VIRTIO_NET_F_CTRL_VQ))
 	{
 	  vring = vif->cxq_vring;
 	  vlib_cli_output (vm, "  Virtqueue (CTRL) %d", vring->queue_id);
 	  vlib_cli_output (vm,
 			   "    qsz %d, last_used_idx %d, desc_next %d, desc_in_use %d",
 			   vring->size, vring->last_used_idx,
 			   vring->desc_next, vring->desc_in_use);
 	  if (vif->is_packed)
 	    {
 	      vlib_cli_output (vm,
 			       "    driver_event.flags 0x%x driver_event.off_wrap %d device_event.flags 0x%x device_event.off_wrap %d",
 			       vring->driver_event->flags,
 			       vring->driver_event->off_wrap,
 			       vring->device_event->flags,
 			       vring->device_event->off_wrap);
 	      vlib_cli_output (vm,
 			       "    avail wrap counter %d, used wrap counter %d",
 			       vring->avail_wrap_counter,
 			       vring->used_wrap_counter);
 	    }
 	  else
 	    {
 	      vlib_cli_output (vm,
 			       "    avail.flags 0x%x avail.idx %d used.flags 0x%x used.idx %d",
 			       vring->avail->flags, vring->avail->idx,
 			       vring->used->flags, vring->used->idx);
 	    }
 	  if (show_descr)
 	    {
 	      vlib_cli_output (vm, "\n  descriptor table:\n");
 	      vlib_cli_output (vm,
 			       "   id          addr         len  flags  next/id      user_addr\n");
 	      vlib_cli_output (vm,
 			       "  ===== ================== ===== ====== ======== ==================\n");
 	      for (j = 0; j < vring->size; j++)
 		{
 		  if (vif->is_packed)
 		    {
 		      vring_packed_desc_t *desc = &vring->packed_desc[j];
 		      vlib_cli_output (vm,
 				       "  %-5d 0x%016lx %-5d 0x%04x %-8d 0x%016lx\n",
 				       j, desc->addr,
 				       desc->len,
 				       desc->flags, desc->id, desc->addr);
 		    }
 		  else
 		    {
 		      vring_desc_t *desc = &vring->desc[j];
 		      vlib_cli_output (vm,
 				       "  %-5d 0x%016lx %-5d 0x%04x %-8d 0x%016lx\n",
 				       j, desc->addr,
 				       desc->len,
 				       desc->flags, desc->next, desc->addr);
 		    }
 		}
 	    }
 	}
     }

 }

 static clib_error_t *
 virtio_init (vlib_main_t * vm)
 {
   virtio_main_t *vim = &virtio_main;
   clib_error_t *error = 0;

   vim->log_default = vlib_log_register_class ("virtio", 0);
   vlib_log_debug (vim->log_default, "initialized");

   return error;
 }

 VLIB_INIT_FUNCTION (virtio_init);

 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	*------------------------------------------------------------------
	* Copyright (c) 2017 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 <sys/types.h>
	#include <sys/stat.h>
	#include <fcntl.h>
	#include <net/if.h>
	#include <linux/if_tun.h>
	#include <sys/ioctl.h>
	#include <sys/eventfd.h>

	#include <vlib/vlib.h>
	#include <vlib/pci/pci.h>
	#include <vlib/unix/unix.h>
	#include <vnet/ethernet/ethernet.h>
	#include <vnet/ip/ip4_packet.h>
	#include <vnet/ip/ip6_packet.h>
	#include <vnet/devices/virtio/virtio.h>
	#include <vnet/devices/virtio/virtio_inline.h>
	#include <vnet/devices/virtio/pci.h>
	#include <vnet/interface/rx_queue_funcs.h>
	#include <vnet/interface/tx_queue_funcs.h>

	virtio_main_t virtio_main;

	#define _IOCTL(fd,a,...) \
	if (ioctl (fd, a, __VA_ARGS__) < 0) \
	{ \
	err = clib_error_return_unix (0, "ioctl(" #a ")"); \
	goto error; \
	}

	static clib_error_t *
	call_read_ready (clib_file_t * uf)
	{
	vnet_main_t *vnm = vnet_get_main ();
	u64 b;

	CLIB_UNUSED (ssize_t size) = read (uf->file_descriptor, &b, sizeof (b));
	vnet_hw_if_rx_queue_set_int_pending (vnm, uf->private_data);

	return 0;
	}


	clib_error_t *
	virtio_vring_init (vlib_main_t * vm, virtio_if_t * vif, u16 idx, u16 sz)
	{
	virtio_vring_t *vring;
	int i;

	if (!is_pow2 (sz))
	return clib_error_return (0, "ring size must be power of 2");

	if (sz > 32768)
	return clib_error_return (0, "ring size must be 32768 or lower");

	if (sz == 0)
	sz = 256;

	if (idx % 2)
	{
	vec_validate_aligned (vif->txq_vrings, TX_QUEUE_ACCESS (idx),
	CLIB_CACHE_LINE_BYTES);
	vring = vec_elt_at_index (vif->txq_vrings, TX_QUEUE_ACCESS (idx));
	clib_spinlock_init (&vring->lockp);
	}
	else
	{
	vec_validate_aligned (vif->rxq_vrings, RX_QUEUE_ACCESS (idx),
	CLIB_CACHE_LINE_BYTES);
	vring = vec_elt_at_index (vif->rxq_vrings, RX_QUEUE_ACCESS (idx));
	}
	i = sizeof (vring_desc_t) * sz;
	i = round_pow2 (i, CLIB_CACHE_LINE_BYTES);
	vring->desc = clib_mem_alloc_aligned (i, CLIB_CACHE_LINE_BYTES);
	clib_memset (vring->desc, 0, i);

	i = sizeof (vring_avail_t) + sz * sizeof (vring->avail->ring[0]);
	i = round_pow2 (i, CLIB_CACHE_LINE_BYTES);
	vring->avail = clib_mem_alloc_aligned (i, CLIB_CACHE_LINE_BYTES);
	clib_memset (vring->avail, 0, i);
	// tell kernel that we don't need interrupt
	vring->avail->flags = VRING_AVAIL_F_NO_INTERRUPT;

	i = sizeof (vring_used_t) + sz * sizeof (vring_used_elem_t);
	i = round_pow2 (i, CLIB_CACHE_LINE_BYTES);
	vring->used = clib_mem_alloc_aligned (i, CLIB_CACHE_LINE_BYTES);
	clib_memset (vring->used, 0, i);

	vring->queue_id = idx;
	ASSERT (vring->buffers == 0);
	vec_validate_aligned (vring->buffers, sz, CLIB_CACHE_LINE_BYTES);

	if (idx & 1)
	{
	clib_memset_u32 (vring->buffers, ~0, sz);
	// tx path: suppress the interrupts from kernel
	vring->call_fd = -1;
	}
	else
	vring->call_fd = eventfd (0, EFD_NONBLOCK \| EFD_CLOEXEC);

	vring->size = sz;
	vring->kick_fd = eventfd (0, EFD_NONBLOCK \| EFD_CLOEXEC);
	virtio_log_debug (vif, "vring %u size %u call_fd %d kick_fd %d", idx,
	vring->size, vring->call_fd, vring->kick_fd);

	return 0;
	}

	inline void
	virtio_free_buffers (vlib_main_t * vm, virtio_vring_t * vring)
	{
	u16 used = vring->desc_in_use;
	u16 last = vring->last_used_idx;
	u16 mask = vring->size - 1;

	while (used)
	{
	vlib_buffer_free (vm, &vring->buffers[last & mask], 1);
	last++;
	used--;
	}
	}

	clib_error_t *
	virtio_vring_free_rx (vlib_main_t * vm, virtio_if_t * vif, u32 idx)
	{
	virtio_vring_t *vring =
	vec_elt_at_index (vif->rxq_vrings, RX_QUEUE_ACCESS (idx));

	clib_file_del_by_index (&file_main, vring->call_file_index);
	close (vring->kick_fd);
	close (vring->call_fd);
	if (vring->used)
	{
	virtio_free_buffers (vm, vring);
	clib_mem_free (vring->used);
	}
	if (vring->desc)
	clib_mem_free (vring->desc);
	if (vring->avail)
	clib_mem_free (vring->avail);
	vec_free (vring->buffers);
	return 0;
	}

	clib_error_t *
	virtio_vring_free_tx (vlib_main_t * vm, virtio_if_t * vif, u32 idx)
	{
	virtio_vring_t *vring =
	vec_elt_at_index (vif->txq_vrings, TX_QUEUE_ACCESS (idx));

	close (vring->kick_fd);
	if (vring->used)
	{
	virtio_free_buffers (vm, vring);
	clib_mem_free (vring->used);
	}
	if (vring->desc)
	clib_mem_free (vring->desc);
	if (vring->avail)
	clib_mem_free (vring->avail);
	vec_free (vring->buffers);
	gro_flow_table_free (vring->flow_table);
	virtio_vring_buffering_free (vm, vring->buffering);
	clib_spinlock_free (&vring->lockp);
	return 0;
	}

	void
	virtio_set_packet_coalesce (virtio_if_t * vif)
	{
	vnet_main_t *vnm = vnet_get_main ();
	vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, vif->hw_if_index);
	virtio_vring_t *vring;
	vif->packet_coalesce = 1;
	vec_foreach (vring, vif->txq_vrings)
	{
	gro_flow_table_init (&vring->flow_table,
	vif->type & (VIRTIO_IF_TYPE_TAP \|
	VIRTIO_IF_TYPE_PCI), hw->tx_node_index);
	}
	}

	clib_error_t *
	virtio_set_packet_buffering (virtio_if_t * vif, u16 buffering_size)
	{
	vnet_main_t *vnm = vnet_get_main ();
	vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, vif->hw_if_index);
	virtio_vring_t *vring;
	clib_error_t *error = 0;
	vif->packet_buffering = 1;

	vec_foreach (vring, vif->txq_vrings)
	{
	if ((error =
	virtio_vring_buffering_init (&vring->buffering, hw->tx_node_index,
	buffering_size)))
	{
	break;
	}
	}

	return error;
	}

	static void
	virtio_vring_fill (vlib_main_t vm, virtio_if_t vif, virtio_vring_t *vring)
	{
	if (vif->is_packed)
	virtio_refill_vring_packed (vm, vif, vif->type, vring,
	vif->virtio_net_hdr_sz,
	virtio_input_node.index);
	else
	virtio_refill_vring_split (vm, vif, vif->type, vring,
	vif->virtio_net_hdr_sz,
	virtio_input_node.index);
	}

	void
	virtio_vring_set_rx_queues (vlib_main_t vm, virtio_if_t vif)
	{
	vnet_main_t *vnm = vnet_get_main ();
	virtio_vring_t *vring;
	u32 i = 0;

	vnet_hw_if_set_input_node (vnm, vif->hw_if_index, virtio_input_node.index);

	vec_foreach (vring, vif->rxq_vrings)
	{
	vring->queue_index = vnet_hw_if_register_rx_queue (
	vnm, vif->hw_if_index, RX_QUEUE_ACCESS (vring->queue_id),
	VNET_HW_IF_RXQ_THREAD_ANY);
	vring->buffer_pool_index = vlib_buffer_pool_get_default_for_numa (
	vm, vnet_hw_if_get_rx_queue_numa_node (vnm, vring->queue_index));
	if (vif->type == VIRTIO_IF_TYPE_TAP \|\| vif->type == VIRTIO_IF_TYPE_TUN)
	{

	clib_file_t f = {
	.read_function = call_read_ready,
	.flags = UNIX_FILE_EVENT_EDGE_TRIGGERED,
	.file_descriptor = vring->call_fd,
	.private_data = vring->queue_index,
	.description = format (0, "%U vring %u", format_virtio_device_name,
	vif->dev_instance, vring->queue_id),
	};

	vring->call_file_index = clib_file_add (&file_main, &f);
	vnet_hw_if_set_rx_queue_file_index (vnm, vring->queue_index,
	vring->call_file_index);
	}
	else if ((vif->type == VIRTIO_IF_TYPE_PCI) && (vif->support_int_mode) &&
	(vif->msix_enabled == VIRTIO_MSIX_ENABLED))
	{
	u32 file_index;
	file_index =
	vlib_pci_get_msix_file_index (vm, vif->pci_dev_handle, i + 1);
	vnet_hw_if_set_rx_queue_file_index (vnm, vring->queue_index,
	file_index);
	i++;
	}
	vnet_hw_if_set_rx_queue_mode (vnm, vring->queue_index,
	VNET_HW_IF_RX_MODE_POLLING);
	vring->mode = VNET_HW_IF_RX_MODE_POLLING;
	virtio_vring_fill (vm, vif, vring);
	}
	vnet_hw_if_update_runtime_data (vnm, vif->hw_if_index);
	}

	void
	virtio_vring_set_tx_queues (vlib_main_t vm, virtio_if_t vif)
	{
	vnet_main_t *vnm = vnet_get_main ();
	virtio_vring_t *vring;

	vec_foreach (vring, vif->txq_vrings)
	{
	vring->queue_index = vnet_hw_if_register_tx_queue (
	vnm, vif->hw_if_index, TX_QUEUE_ACCESS (vring->queue_id));
	}

	if (vif->num_txqs == 0)
	{
	virtio_log_error (vif, "Interface %U has 0 txq",
	format_vnet_hw_if_index_name, vnm, vif->hw_if_index);
	return;
	}

	for (u32 j = 0; j < vlib_get_n_threads (); j++)
	{
	u32 qi = vif->txq_vrings[j % vif->num_txqs].queue_index;
	vnet_hw_if_tx_queue_assign_thread (vnm, qi, j);
	}

	vnet_hw_if_update_runtime_data (vnm, vif->hw_if_index);
	}

	inline void
	virtio_set_net_hdr_size (virtio_if_t * vif)
	{
	if (vif->features & VIRTIO_FEATURE (VIRTIO_NET_F_MRG_RXBUF) \|\|
	vif->features & VIRTIO_FEATURE (VIRTIO_F_VERSION_1))
	vif->virtio_net_hdr_sz = sizeof (virtio_net_hdr_v1_t);
	else
	vif->virtio_net_hdr_sz = sizeof (virtio_net_hdr_t);
	}

	inline void
	virtio_show (vlib_main_t vm, u32 hw_if_indices, u8 show_descr,
	virtio_if_type_t type)
	{
	u32 i, j, hw_if_index;
	virtio_if_t *vif;
	vnet_main_t *vnm = &vnet_main;
	virtio_main_t *mm = &virtio_main;
	virtio_vring_t *vring;
	struct feat_struct
	{
	u8 bit;
	char *str;
	};
	struct feat_struct *feat_entry;

	static struct feat_struct feat_array[] = {
	#define _(s,b) { .str = #s, .bit = b, },
	foreach_virtio_net_features
	#undef _
	{.str = NULL}
	};

	struct feat_struct *flag_entry;
	static struct feat_struct flags_array[] = {
	#define _(b,e,s) { .bit = b, .str = s, },
	foreach_virtio_if_flag
	#undef _
	{.str = NULL}
	};

	if (!hw_if_indices)
	return;

	for (hw_if_index = 0; hw_if_index < vec_len (hw_if_indices); hw_if_index++)
	{
	vnet_hw_interface_t *hi =
	vnet_get_hw_interface (vnm, hw_if_indices[hw_if_index]);
	vif = pool_elt_at_index (mm->interfaces, hi->dev_instance);
	if (vif->type != type)
	continue;
	vlib_cli_output (vm, "Interface: %U (ifindex %d)",
	format_vnet_hw_if_index_name, vnm,
	hw_if_indices[hw_if_index], vif->hw_if_index);
	if (type == VIRTIO_IF_TYPE_PCI)
	{
	vlib_cli_output (vm, " PCI Address: %U", format_vlib_pci_addr,
	&vif->pci_addr);
	}
	if (type & (VIRTIO_IF_TYPE_TAP \| VIRTIO_IF_TYPE_TUN))
	{
	u8 *str = 0;
	if (vif->host_if_name)
	vlib_cli_output (vm, " name \"%s\"", vif->host_if_name);
	if (vif->net_ns)
	vlib_cli_output (vm, " host-ns \"%s\"", vif->net_ns);
	if (vif->host_mtu_size)
	vlib_cli_output (vm, " host-mtu-size \"%d\"",
	vif->host_mtu_size);
	if (type == VIRTIO_IF_TYPE_TAP)
	vlib_cli_output (vm, " host-mac-addr: %U",
	format_ethernet_address, vif->host_mac_addr);
	vlib_cli_output (vm, " host-carrier-up: %u", vif->host_carrier_up);

	vec_foreach_index (i, vif->vhost_fds)
	str = format (str, " %d", vif->vhost_fds[i]);
	vlib_cli_output (vm, " vhost-fds%v", str);
	vec_free (str);
	vec_foreach_index (i, vif->tap_fds)
	str = format (str, " %d", vif->tap_fds[i]);
	vlib_cli_output (vm, " tap-fds%v", str);
	vec_free (str);
	}
	vlib_cli_output (vm, " gso-enabled %d", vif->gso_enabled);
	vlib_cli_output (vm, " csum-enabled %d", vif->csum_offload_enabled);
	vlib_cli_output (vm, " packet-coalesce %d", vif->packet_coalesce);
	vlib_cli_output (vm, " packet-buffering %d", vif->packet_buffering);
	if (type & (VIRTIO_IF_TYPE_TAP \| VIRTIO_IF_TYPE_PCI))
	vlib_cli_output (vm, " Mac Address: %U", format_ethernet_address,
	vif->mac_addr);
	vlib_cli_output (vm, " Device instance: %u", vif->dev_instance);
	vlib_cli_output (vm, " flags 0x%x", vif->flags);
	flag_entry = (struct feat_struct *) &flags_array;
	while (flag_entry->str)
	{
	if (vif->flags & (1ULL << flag_entry->bit))
	vlib_cli_output (vm, " %s (%d)", flag_entry->str,
	flag_entry->bit);
	flag_entry++;
	}
	if (type == VIRTIO_IF_TYPE_PCI)
	{
	device_status (vm, vif);
	}
	vlib_cli_output (vm, " features 0x%lx", vif->features);
	feat_entry = (struct feat_struct *) &feat_array;
	while (feat_entry->str)
	{
	if (vif->features & (1ULL << feat_entry->bit))
	vlib_cli_output (vm, " %s (%d)", feat_entry->str,
	feat_entry->bit);
	feat_entry++;
	}
	vlib_cli_output (vm, " remote-features 0x%lx", vif->remote_features);
	feat_entry = (struct feat_struct *) &feat_array;
	while (feat_entry->str)
	{
	if (vif->remote_features & (1ULL << feat_entry->bit))
	vlib_cli_output (vm, " %s (%d)", feat_entry->str,
	feat_entry->bit);
	feat_entry++;
	}
	vlib_cli_output (vm, " Number of RX Virtqueue %u", vif->num_rxqs);
	vlib_cli_output (vm, " Number of TX Virtqueue %u", vif->num_txqs);
	if (type == VIRTIO_IF_TYPE_PCI && vif->cxq_vring != NULL &&
	vif->features & VIRTIO_FEATURE (VIRTIO_NET_F_CTRL_VQ))
	vlib_cli_output (vm, " Number of CTRL Virtqueue 1");
	vec_foreach_index (i, vif->rxq_vrings)
	{
	vring = vec_elt_at_index (vif->rxq_vrings, i);
	vlib_cli_output (vm, " Virtqueue (RX) %d", vring->queue_id);
	vlib_cli_output (vm,
	" qsz %d, last_used_idx %d, desc_next %d, desc_in_use %d",
	vring->size, vring->last_used_idx, vring->desc_next,
	vring->desc_in_use);
	if (vif->is_packed)
	{
	vlib_cli_output (vm,
	" driver_event.flags 0x%x driver_event.off_wrap %d device_event.flags 0x%x device_event.off_wrap %d",
	vring->driver_event->flags,
	vring->driver_event->off_wrap,
	vring->device_event->flags,
	vring->device_event->off_wrap);
	vlib_cli_output (vm,
	" avail wrap counter %d, used wrap counter %d",
	vring->avail_wrap_counter,
	vring->used_wrap_counter);
	}
	else
	vlib_cli_output (vm,
	" avail.flags 0x%x avail.idx %d used.flags 0x%x used.idx %d",
	vring->avail->flags, vring->avail->idx,
	vring->used->flags, vring->used->idx);
	if (type & (VIRTIO_IF_TYPE_TAP \| VIRTIO_IF_TYPE_TUN))
	{
	vlib_cli_output (vm, " kickfd %d, callfd %d", vring->kick_fd,
	vring->call_fd);
	}
	if (show_descr)
	{
	vlib_cli_output (vm, "\n descriptor table:\n");
	vlib_cli_output (vm,
	" id addr len flags next/id user_addr\n");
	vlib_cli_output (vm,
	" ===== ================== ===== ====== ======= ==================\n");
	for (j = 0; j < vring->size; j++)
	{
	if (vif->is_packed)
	{
	vring_packed_desc_t *desc = &vring->packed_desc[j];
	vlib_cli_output (vm,
	" %-5d 0x%016lx %-5d 0x%04x %-8d 0x%016lx\n",
	j, desc->addr,
	desc->len,
	desc->flags, desc->id, desc->addr);
	}
	else
	{
	vring_desc_t *desc = &vring->desc[j];
	vlib_cli_output (vm,
	" %-5d 0x%016lx %-5d 0x%04x %-8d 0x%016lx\n",
	j, desc->addr,
	desc->len,
	desc->flags, desc->next, desc->addr);
	}
	}
	}
	}
	vec_foreach_index (i, vif->txq_vrings)
	{
	vring = vec_elt_at_index (vif->txq_vrings, i);
	vlib_cli_output (vm, " Virtqueue (TX) %d", vring->queue_id);
	vlib_cli_output (vm,
	" qsz %d, last_used_idx %d, desc_next %d, desc_in_use %d",
	vring->size, vring->last_used_idx, vring->desc_next,
	vring->desc_in_use);
	if (vif->is_packed)
	{
	vlib_cli_output (vm,
	" driver_event.flags 0x%x driver_event.off_wrap %d device_event.flags 0x%x device_event.off_wrap %d",
	vring->driver_event->flags,
	vring->driver_event->off_wrap,
	vring->device_event->flags,
	vring->device_event->off_wrap);
	vlib_cli_output (vm,
	" avail wrap counter %d, used wrap counter %d",
	vring->avail_wrap_counter,
	vring->used_wrap_counter);
	}
	else
	vlib_cli_output (vm,
	" avail.flags 0x%x avail.idx %d used.flags 0x%x used.idx %d",
	vring->avail->flags, vring->avail->idx,
	vring->used->flags, vring->used->idx);
	if (type & (VIRTIO_IF_TYPE_TAP \| VIRTIO_IF_TYPE_TUN))
	{
	vlib_cli_output (vm, " kickfd %d, callfd %d", vring->kick_fd,
	vring->call_fd);
	}
	if (vring->flow_table)
	{
	vlib_cli_output (vm, " %U", gro_flow_table_format,
	vring->flow_table);
	}
	if (vif->packet_buffering)
	{
	vlib_cli_output (vm, " %U", virtio_vring_buffering_format,
	vring->buffering);
	}
	if (show_descr)
	{
	vlib_cli_output (vm, "\n descriptor table:\n");
	vlib_cli_output (vm,
	" id addr len flags next/id user_addr\n");
	vlib_cli_output (vm,
	" ===== ================== ===== ====== ======== ==================\n");
	for (j = 0; j < vring->size; j++)
	{
	if (vif->is_packed)
	{
	vring_packed_desc_t *desc = &vring->packed_desc[j];
	vlib_cli_output (vm,
	" %-5d 0x%016lx %-5d 0x%04x %-8d 0x%016lx\n",
	j, desc->addr,
	desc->len,
	desc->flags, desc->id, desc->addr);
	}
	else
	{
	vring_desc_t *desc = &vring->desc[j];
	vlib_cli_output (vm,
	" %-5d 0x%016lx %-5d 0x%04x %-8d 0x%016lx\n",
	j, desc->addr,
	desc->len,
	desc->flags, desc->next, desc->addr);
	}
	}
	}
	}
	if (type == VIRTIO_IF_TYPE_PCI && vif->cxq_vring != NULL &&
	vif->features & VIRTIO_FEATURE (VIRTIO_NET_F_CTRL_VQ))
	{
	vring = vif->cxq_vring;
	vlib_cli_output (vm, " Virtqueue (CTRL) %d", vring->queue_id);
	vlib_cli_output (vm,
	" qsz %d, last_used_idx %d, desc_next %d, desc_in_use %d",
	vring->size, vring->last_used_idx,
	vring->desc_next, vring->desc_in_use);
	if (vif->is_packed)
	{
	vlib_cli_output (vm,
	" driver_event.flags 0x%x driver_event.off_wrap %d device_event.flags 0x%x device_event.off_wrap %d",
	vring->driver_event->flags,
	vring->driver_event->off_wrap,
	vring->device_event->flags,
	vring->device_event->off_wrap);
	vlib_cli_output (vm,
	" avail wrap counter %d, used wrap counter %d",
	vring->avail_wrap_counter,
	vring->used_wrap_counter);
	}
	else
	{
	vlib_cli_output (vm,
	" avail.flags 0x%x avail.idx %d used.flags 0x%x used.idx %d",
	vring->avail->flags, vring->avail->idx,
	vring->used->flags, vring->used->idx);
	}
	if (show_descr)
	{
	vlib_cli_output (vm, "\n descriptor table:\n");
	vlib_cli_output (vm,
	" id addr len flags next/id user_addr\n");
	vlib_cli_output (vm,
	" ===== ================== ===== ====== ======== ==================\n");
	for (j = 0; j < vring->size; j++)
	{
	if (vif->is_packed)
	{
	vring_packed_desc_t *desc = &vring->packed_desc[j];
	vlib_cli_output (vm,
	" %-5d 0x%016lx %-5d 0x%04x %-8d 0x%016lx\n",
	j, desc->addr,
	desc->len,
	desc->flags, desc->id, desc->addr);
	}
	else
	{
	vring_desc_t *desc = &vring->desc[j];
	vlib_cli_output (vm,
	" %-5d 0x%016lx %-5d 0x%04x %-8d 0x%016lx\n",
	j, desc->addr,
	desc->len,
	desc->flags, desc->next, desc->addr);
	}
	}
	}
	}
	}

	}

	static clib_error_t *
	virtio_init (vlib_main_t * vm)
	{
	virtio_main_t *vim = &virtio_main;
	clib_error_t *error = 0;

	vim->log_default = vlib_log_register_class ("virtio", 0);
	vlib_log_debug (vim->log_default, "initialized");

	return error;
	}

	VLIB_INIT_FUNCTION (virtio_init);

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