vhost: convert vhost device driver to a plugin

convert vhost device driver to a plugin as described in
https://jira.fd.io/browse/VPP-2065

Type: improvement

Signed-off-by: Steven Luong <sluong@cisco.com>
Change-Id: Ibfe2f351bcaed36a04b136d082ae414145dd37b5

1 files changed, 0 insertions, 1145 deletions

diff --git a/src/vnet/devices/virtio/vhost_user_output.c b/src/vnet/devices/virtio/vhost_user_output.c
deleted file mode 100644
index 3b7bf97c3f8..00000000000
--- a/src/vnet/devices/virtio/vhost_user_output.c
+++ /dev/null
@@ -1,1145 +0,0 @@
-/*
- *------------------------------------------------------------------
- * vhost-user-output
- *
- * 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 <stddef.h>
-#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/ethernet/ethernet.h>
-#include <vnet/devices/devices.h>
-#include <vnet/feature/feature.h>
-#include <vnet/ip/ip_psh_cksum.h>
-
-#include <vnet/devices/virtio/vhost_user.h>
-#include <vnet/devices/virtio/vhost_user_inline.h>
-
-#include <vnet/gso/hdr_offset_parser.h>
-/*
- * On the transmit side, we keep processing the buffers from vlib in the while
- * loop and prepare the copy order to be executed later. However, the static
- * array which we keep the copy order is limited to VHOST_USER_COPY_ARRAY_N
- * entries. In order to not corrupt memory, we have to do the copy when the
- * static array reaches the copy threshold. We subtract 40 in case the code
- * goes into the inner loop for a maximum of 64k frames which may require
- * more array entries. We subtract 200 because our default buffer size is
- * 2048 and the default desc len is likely 1536. While it takes less than 40
- * vlib buffers for the jumbo frame, it may take twice as much descriptors
- * for the same jumbo frame. Use 200 for the extra head room.
- */
-#define VHOST_USER_TX_COPY_THRESHOLD (VHOST_USER_COPY_ARRAY_N - 200)
-
-extern vnet_device_class_t vhost_user_device_class;
-
-#define foreach_vhost_user_tx_func_error      \
-  _(NONE, "no error")  \
-  _(NOT_READY, "vhost vring not ready")  \
-  _(DOWN, "vhost interface is down")  \
-  _(PKT_DROP_NOBUF, "tx packet drops (no available descriptors)")  \
-  _(PKT_DROP_NOMRG, "tx packet drops (cannot merge descriptors)")  \
-  _(MMAP_FAIL, "mmap failure") \
-  _(INDIRECT_OVERFLOW, "indirect descriptor table overflow")
-
-typedef enum
-{
-#define _(f,s) VHOST_USER_TX_FUNC_ERROR_##f,
-  foreach_vhost_user_tx_func_error
-#undef _
-    VHOST_USER_TX_FUNC_N_ERROR,
-} vhost_user_tx_func_error_t;
-
-static __clib_unused char *vhost_user_tx_func_error_strings[] = {
-#define _(n,s) s,
-  foreach_vhost_user_tx_func_error
-#undef _
-};
-
-static __clib_unused u8 *
-format_vhost_user_interface_name (u8 * s, va_list * args)
-{
-  u32 i = va_arg (*args, u32);
-  u32 show_dev_instance = ~0;
-  vhost_user_main_t *vum = &vhost_user_main;
-
-  if (i < vec_len (vum->show_dev_instance_by_real_dev_instance))
-    show_dev_instance = vum->show_dev_instance_by_real_dev_instance[i];
-
-  if (show_dev_instance != ~0)
-    i = show_dev_instance;
-
-  s = format (s, "VirtualEthernet0/0/%d", i);
-  return s;
-}
-
-static __clib_unused int
-vhost_user_name_renumber (vnet_hw_interface_t * hi, u32 new_dev_instance)
-{
-  // FIXME: check if the new dev instance is already used
-  vhost_user_main_t *vum = &vhost_user_main;
-  vhost_user_intf_t *vui = pool_elt_at_index (vum->vhost_user_interfaces,
-					      hi->dev_instance);
-
-  vec_validate_init_empty (vum->show_dev_instance_by_real_dev_instance,
-			   hi->dev_instance, ~0);
-
-  vum->show_dev_instance_by_real_dev_instance[hi->dev_instance] =
-    new_dev_instance;
-
-  vu_log_debug (vui, "renumbered vhost-user interface dev_instance %d to %d",
-		hi->dev_instance, new_dev_instance);
-
-  return 0;
-}
-
-static_always_inline void
-vhost_user_tx_trace (vhost_trace_t * t,
-		     vhost_user_intf_t * vui, u16 qid,
-		     vlib_buffer_t * b, vhost_user_vring_t * rxvq)
-{
-  vhost_user_main_t *vum = &vhost_user_main;
-  u32 last_avail_idx = rxvq->last_avail_idx;
-  u32 desc_current = rxvq->avail->ring[last_avail_idx & rxvq->qsz_mask];
-  vnet_virtio_vring_desc_t *hdr_desc = 0;
-  u32 hint = 0;
-
-  clib_memset (t, 0, sizeof (*t));
-  t->device_index = vui - vum->vhost_user_interfaces;
-  t->qid = qid;
-
-  hdr_desc = &rxvq->desc[desc_current];
-  if (rxvq->desc[desc_current].flags & VRING_DESC_F_INDIRECT)
-    {
-      t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_INDIRECT;
-      /* Header is the first here */
-      hdr_desc = map_guest_mem (vui, rxvq->desc[desc_current].addr, &hint);
-    }
-  if (rxvq->desc[desc_current].flags & VRING_DESC_F_NEXT)
-    {
-      t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SIMPLE_CHAINED;
-    }
-  if (!(rxvq->desc[desc_current].flags & VRING_DESC_F_NEXT) &&
-      !(rxvq->desc[desc_current].flags & VRING_DESC_F_INDIRECT))
-    {
-      t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SINGLE_DESC;
-    }
-
-  t->first_desc_len = hdr_desc ? hdr_desc->len : 0;
-}
-
-static_always_inline u32
-vhost_user_tx_copy (vhost_user_intf_t * vui, vhost_copy_t * cpy,
-		    u16 copy_len, u32 * map_hint)
-{
-  void *dst0, *dst1, *dst2, *dst3;
-  if (PREDICT_TRUE (copy_len >= 4))
-    {
-      if (PREDICT_FALSE (!(dst2 = map_guest_mem (vui, cpy[0].dst, map_hint))))
-	return 1;
-      if (PREDICT_FALSE (!(dst3 = map_guest_mem (vui, cpy[1].dst, map_hint))))
-	return 1;
-      while (PREDICT_TRUE (copy_len >= 4))
-	{
-	  dst0 = dst2;
-	  dst1 = dst3;
-
-	  if (PREDICT_FALSE
-	      (!(dst2 = map_guest_mem (vui, cpy[2].dst, map_hint))))
-	    return 1;
-	  if (PREDICT_FALSE
-	      (!(dst3 = map_guest_mem (vui, cpy[3].dst, map_hint))))
-	    return 1;
-
-	  clib_prefetch_load ((void *) cpy[2].src);
-	  clib_prefetch_load ((void *) cpy[3].src);
-
-	  clib_memcpy_fast (dst0, (void *) cpy[0].src, cpy[0].len);
-	  clib_memcpy_fast (dst1, (void *) cpy[1].src, cpy[1].len);
-
-	  vhost_user_log_dirty_pages_2 (vui, cpy[0].dst, cpy[0].len, 1);
-	  vhost_user_log_dirty_pages_2 (vui, cpy[1].dst, cpy[1].len, 1);
-	  copy_len -= 2;
-	  cpy += 2;
-	}
-    }
-  while (copy_len)
-    {
-      if (PREDICT_FALSE (!(dst0 = map_guest_mem (vui, cpy->dst, map_hint))))
-	return 1;
-      clib_memcpy_fast (dst0, (void *) cpy->src, cpy->len);
-      vhost_user_log_dirty_pages_2 (vui, cpy->dst, cpy->len, 1);
-      copy_len -= 1;
-      cpy += 1;
-    }
-  return 0;
-}
-
-static_always_inline void
-vhost_user_handle_tx_offload (vhost_user_intf_t *vui, vlib_buffer_t *b,
-			      vnet_virtio_net_hdr_t *hdr)
-{
-  generic_header_offset_t gho = { 0 };
-  int is_ip4 = b->flags & VNET_BUFFER_F_IS_IP4;
-  int is_ip6 = b->flags & VNET_BUFFER_F_IS_IP6;
-  vnet_buffer_oflags_t oflags = vnet_buffer (b)->oflags;
-  u16 psh_cksum = 0;
-  ip4_header_t *ip4 = 0;
-  ip6_header_t *ip6 = 0;
-
-  ASSERT (!(is_ip4 && is_ip6));
-  vnet_generic_header_offset_parser (b, &gho, 1 /* l2 */ , is_ip4, is_ip6);
-  if (oflags & VNET_BUFFER_OFFLOAD_F_IP_CKSUM)
-    {
-      ip4 =
-	(ip4_header_t *) (vlib_buffer_get_current (b) + gho.l3_hdr_offset);
-      ip4->checksum = ip4_header_checksum (ip4);
-      psh_cksum = ip4_pseudo_header_cksum (ip4);
-    }
-  else
-    {
-      ip6 = (ip6_header_t *) (vlib_buffer_get_current (b) + gho.l3_hdr_offset);
-      psh_cksum = ip6_pseudo_header_cksum (ip6);
-    }
-
-  /* checksum offload */
-  if (oflags & VNET_BUFFER_OFFLOAD_F_UDP_CKSUM)
-    {
-      udp_header_t *udp =
-	(udp_header_t *) (vlib_buffer_get_current (b) + gho.l4_hdr_offset);
-      udp->checksum = psh_cksum;
-      hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-      hdr->csum_start = gho.l4_hdr_offset;
-      hdr->csum_offset = offsetof (udp_header_t, checksum);
-    }
-  else if (oflags & VNET_BUFFER_OFFLOAD_F_TCP_CKSUM)
-    {
-      tcp_header_t *tcp =
-	(tcp_header_t *) (vlib_buffer_get_current (b) + gho.l4_hdr_offset);
-      tcp->checksum = psh_cksum;
-      hdr->flags = VIRTIO_NET_HDR_F_NEEDS_CSUM;
-      hdr->csum_start = gho.l4_hdr_offset;
-      hdr->csum_offset = offsetof (tcp_header_t, checksum);
-    }
-
-  /* GSO offload */
-  if (b->flags & VNET_BUFFER_F_GSO)
-    {
-      if (oflags & VNET_BUFFER_OFFLOAD_F_TCP_CKSUM)
-	{
-	  if (is_ip4 &&
-	      (vui->features & VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_TSO4)))
-	    {
-	      hdr->gso_size = vnet_buffer2 (b)->gso_size;
-	      hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV4;
-	    }
-	  else if (is_ip6 &&
-		   (vui->features & VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_TSO6)))
-	    {
-	      hdr->gso_size = vnet_buffer2 (b)->gso_size;
-	      hdr->gso_type = VIRTIO_NET_HDR_GSO_TCPV6;
-	    }
-	}
-      else if ((vui->features & VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_UFO)) &&
-	       (oflags & VNET_BUFFER_OFFLOAD_F_UDP_CKSUM))
-	{
-	  hdr->gso_size = vnet_buffer2 (b)->gso_size;
-	  hdr->gso_type = VIRTIO_NET_HDR_GSO_UDP;
-	}
-    }
-}
-
-static_always_inline void
-vhost_user_mark_desc_available (vlib_main_t * vm, vhost_user_intf_t * vui,
-				vhost_user_vring_t * rxvq,
-				u16 * n_descs_processed, u8 chained,
-				vlib_frame_t * frame, u32 n_left)
-{
-  u16 desc_idx, flags;
-  vnet_virtio_vring_packed_desc_t *desc_table = rxvq->packed_desc;
-  u16 last_used_idx = rxvq->last_used_idx;
-
-  if (PREDICT_FALSE (*n_descs_processed == 0))
-    return;
-
-  if (rxvq->used_wrap_counter)
-    flags = desc_table[last_used_idx & rxvq->qsz_mask].flags |
-      (VRING_DESC_F_AVAIL | VRING_DESC_F_USED);
-  else
-    flags = desc_table[last_used_idx & rxvq->qsz_mask].flags &
-      ~(VRING_DESC_F_AVAIL | VRING_DESC_F_USED);
-
-  vhost_user_advance_last_used_idx (rxvq);
-
-  for (desc_idx = 1; desc_idx < *n_descs_processed; desc_idx++)
-    {
-      if (rxvq->used_wrap_counter)
-	desc_table[rxvq->last_used_idx & rxvq->qsz_mask].flags |=
-	  (VRING_DESC_F_AVAIL | VRING_DESC_F_USED);
-      else
-	desc_table[rxvq->last_used_idx & rxvq->qsz_mask].flags &=
-	  ~(VRING_DESC_F_AVAIL | VRING_DESC_F_USED);
-      vhost_user_advance_last_used_idx (rxvq);
-    }
-
-  desc_table[last_used_idx & rxvq->qsz_mask].flags = flags;
-
-  *n_descs_processed = 0;
-
-  if (chained)
-    {
-      vnet_virtio_vring_packed_desc_t *desc_table = rxvq->packed_desc;
-
-      while (desc_table[rxvq->last_used_idx & rxvq->qsz_mask].flags &
-	     VRING_DESC_F_NEXT)
-	vhost_user_advance_last_used_idx (rxvq);
-
-      /* Advance past the current chained table entries */
-      vhost_user_advance_last_used_idx (rxvq);
-    }
-
-  /* interrupt (call) handling */
-  if ((rxvq->callfd_idx != ~0) &&
-      (rxvq->avail_event->flags != VRING_EVENT_F_DISABLE))
-    {
-      vhost_user_main_t *vum = &vhost_user_main;
-
-      rxvq->n_since_last_int += frame->n_vectors - n_left;
-      if (rxvq->n_since_last_int > vum->coalesce_frames)
-	vhost_user_send_call (vm, vui, rxvq);
-    }
-}
-
-static_always_inline void
-vhost_user_tx_trace_packed (vhost_trace_t * t, vhost_user_intf_t * vui,
-			    u16 qid, vlib_buffer_t * b,
-			    vhost_user_vring_t * rxvq)
-{
-  vhost_user_main_t *vum = &vhost_user_main;
-  u32 last_avail_idx = rxvq->last_avail_idx;
-  u32 desc_current = last_avail_idx & rxvq->qsz_mask;
-  vnet_virtio_vring_packed_desc_t *hdr_desc = 0;
-  u32 hint = 0;
-
-  clib_memset (t, 0, sizeof (*t));
-  t->device_index = vui - vum->vhost_user_interfaces;
-  t->qid = qid;
-
-  hdr_desc = &rxvq->packed_desc[desc_current];
-  if (rxvq->packed_desc[desc_current].flags & VRING_DESC_F_INDIRECT)
-    {
-      t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_INDIRECT;
-      /* Header is the first here */
-      hdr_desc = map_guest_mem (vui, rxvq->packed_desc[desc_current].addr,
-				&hint);
-    }
-  if (rxvq->packed_desc[desc_current].flags & VRING_DESC_F_NEXT)
-    {
-      t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SIMPLE_CHAINED;
-    }
-  if (!(rxvq->packed_desc[desc_current].flags & VRING_DESC_F_NEXT) &&
-      !(rxvq->packed_desc[desc_current].flags & VRING_DESC_F_INDIRECT))
-    {
-      t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SINGLE_DESC;
-    }
-
-  t->first_desc_len = hdr_desc ? hdr_desc->len : 0;
-}
-
-static_always_inline uword
-vhost_user_device_class_packed (vlib_main_t *vm, vlib_node_runtime_t *node,
-				vlib_frame_t *frame, vhost_user_intf_t *vui,
-				vhost_user_vring_t *rxvq)
-{
-  u32 *buffers = vlib_frame_vector_args (frame);
-  u32 n_left = frame->n_vectors;
-  vhost_user_main_t *vum = &vhost_user_main;
-  u32 qid = rxvq->qid;
-  u8 error;
-  u32 thread_index = vm->thread_index;
-  vhost_cpu_t *cpu = &vum->cpus[thread_index];
-  u32 map_hint = 0;
-  u8 retry = 8;
-  u16 copy_len;
-  u16 tx_headers_len;
-  vnet_virtio_vring_packed_desc_t *desc_table;
-  u32 or_flags;
-  u16 desc_head, desc_index, desc_len;
-  u16 n_descs_processed;
-  u8 indirect, chained;
-
-retry:
-  error = VHOST_USER_TX_FUNC_ERROR_NONE;
-  tx_headers_len = 0;
-  copy_len = 0;
-  n_descs_processed = 0;
-
-  while (n_left > 0)
-    {
-      vlib_buffer_t *b0, *current_b0;
-      uword buffer_map_addr;
-      u32 buffer_len;
-      u16 bytes_left;
-      u32 total_desc_len = 0;
-      u16 n_entries = 0;
-
-      indirect = 0;
-      chained = 0;
-      if (PREDICT_TRUE (n_left > 1))
-	vlib_prefetch_buffer_with_index (vm, buffers[1], LOAD);
-
-      b0 = vlib_get_buffer (vm, buffers[0]);
-      if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
-	{
-	  cpu->current_trace = vlib_add_trace (vm, node, b0,
-					       sizeof (*cpu->current_trace));
-	  vhost_user_tx_trace_packed (cpu->current_trace, vui, qid / 2, b0,
-				      rxvq);
-	}
-
-      desc_table = rxvq->packed_desc;
-      desc_head = desc_index = rxvq->last_avail_idx & rxvq->qsz_mask;
-      if (PREDICT_FALSE (!vhost_user_packed_desc_available (rxvq, desc_head)))
-	{
-	  error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
-	  goto done;
-	}
-      /*
-       * Go deeper in case of indirect descriptor.
-       * To test it, turn off mrg_rxbuf.
-       */
-      if (desc_table[desc_head].flags & VRING_DESC_F_INDIRECT)
-	{
-	  indirect = 1;
-	  if (PREDICT_FALSE (desc_table[desc_head].len <
-			     sizeof (vnet_virtio_vring_packed_desc_t)))
-	    {
-	      error = VHOST_USER_TX_FUNC_ERROR_INDIRECT_OVERFLOW;
-	      goto done;
-	    }
-	  n_entries = desc_table[desc_head].len >> 4;
-	  desc_table = map_guest_mem (vui, desc_table[desc_index].addr,
-				      &map_hint);
-	  if (PREDICT_FALSE (desc_table == 0))
-	    {
-	      error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
-	      goto done;
-	    }
-	  desc_index = 0;
-	}
-      else if (rxvq->packed_desc[desc_head].flags & VRING_DESC_F_NEXT)
-	chained = 1;
-
-      desc_len = vui->virtio_net_hdr_sz;
-      buffer_map_addr = desc_table[desc_index].addr;
-      buffer_len = desc_table[desc_index].len;
-
-      /* Get a header from the header array */
-      vnet_virtio_net_hdr_mrg_rxbuf_t *hdr = &cpu->tx_headers[tx_headers_len];
-      tx_headers_len++;
-      hdr->hdr.flags = 0;
-      hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
-      hdr->num_buffers = 1;
-
-      or_flags = (b0->flags & VNET_BUFFER_F_OFFLOAD);
-
-      /* Guest supports csum offload and buffer requires checksum offload? */
-      if (or_flags &&
-	  (vui->features & VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_CSUM)))
-	vhost_user_handle_tx_offload (vui, b0, &hdr->hdr);
-
-      /* Prepare a copy order executed later for the header */
-      ASSERT (copy_len < VHOST_USER_COPY_ARRAY_N);
-      vhost_copy_t *cpy = &cpu->copy[copy_len];
-      copy_len++;
-      cpy->len = vui->virtio_net_hdr_sz;
-      cpy->dst = buffer_map_addr;
-      cpy->src = (uword) hdr;
-
-      buffer_map_addr += vui->virtio_net_hdr_sz;
-      buffer_len -= vui->virtio_net_hdr_sz;
-      bytes_left = b0->current_length;
-      current_b0 = b0;
-      while (1)
-	{
-	  if (buffer_len == 0)
-	    {
-	      /* Get new output */
-	      if (chained)
-		{
-		  /*
-		   * Next one is chained
-		   * Test it with both indirect and mrg_rxbuf off
-		   */
-		  if (PREDICT_FALSE (!(desc_table[desc_index].flags &
-				       VRING_DESC_F_NEXT)))
-		    {
-		      /*
-		       * Last descriptor in chain.
-		       * Dequeue queued descriptors for this packet
-		       */
-		      vhost_user_dequeue_chained_descs (rxvq,
-							&n_descs_processed);
-		      error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
-		      goto done;
-		    }
-		  vhost_user_advance_last_avail_idx (rxvq);
-		  desc_index = rxvq->last_avail_idx & rxvq->qsz_mask;
-		  n_descs_processed++;
-		  buffer_map_addr = desc_table[desc_index].addr;
-		  buffer_len = desc_table[desc_index].len;
-		  total_desc_len += desc_len;
-		  desc_len = 0;
-		}
-	      else if (indirect)
-		{
-		  /*
-		   * Indirect table
-		   * Test it with mrg_rxnuf off
-		   */
-		  if (PREDICT_TRUE (n_entries > 0))
-		    n_entries--;
-		  else
-		    {
-		      /* Dequeue queued descriptors for this packet */
-		      vhost_user_dequeue_chained_descs (rxvq,
-							&n_descs_processed);
-		      error = VHOST_USER_TX_FUNC_ERROR_INDIRECT_OVERFLOW;
-		      goto done;
-		    }
-		  total_desc_len += desc_len;
-		  desc_index = (desc_index + 1) & rxvq->qsz_mask;
-		  buffer_map_addr = desc_table[desc_index].addr;
-		  buffer_len = desc_table[desc_index].len;
-		  desc_len = 0;
-		}
-	      else if (vui->virtio_net_hdr_sz == 12)
-		{
-		  /*
-		   * MRG is available
-		   * This is the default setting for the guest VM
-		   */
-		  vnet_virtio_net_hdr_mrg_rxbuf_t *hdr =
-		    &cpu->tx_headers[tx_headers_len - 1];
-
-		  desc_table[desc_index].len = desc_len;
-		  vhost_user_advance_last_avail_idx (rxvq);
-		  desc_head = desc_index =
-		    rxvq->last_avail_idx & rxvq->qsz_mask;
-		  hdr->num_buffers++;
-		  n_descs_processed++;
-		  desc_len = 0;
-
-		  if (PREDICT_FALSE (!vhost_user_packed_desc_available
-				     (rxvq, desc_index)))
-		    {
-		      /* Dequeue queued descriptors for this packet */
-		      vhost_user_dequeue_descs (rxvq, hdr,
-						&n_descs_processed);
-		      error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
-		      goto done;
-		    }
-
-		  buffer_map_addr = desc_table[desc_index].addr;
-		  buffer_len = desc_table[desc_index].len;
-		}
-	      else
-		{
-		  error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOMRG;
-		  goto done;
-		}
-	    }
-
-	  ASSERT (copy_len < VHOST_USER_COPY_ARRAY_N);
-	  vhost_copy_t *cpy = &cpu->copy[copy_len];
-	  copy_len++;
-	  cpy->len = bytes_left;
-	  cpy->len = (cpy->len > buffer_len) ? buffer_len : cpy->len;
-	  cpy->dst = buffer_map_addr;
-	  cpy->src = (uword) vlib_buffer_get_current (current_b0) +
-	    current_b0->current_length - bytes_left;
-
-	  bytes_left -= cpy->len;
-	  buffer_len -= cpy->len;
-	  buffer_map_addr += cpy->len;
-	  desc_len += cpy->len;
-
-	  clib_prefetch_load (&rxvq->packed_desc);
-
-	  /* Check if vlib buffer has more data. If not, get more or break */
-	  if (PREDICT_TRUE (!bytes_left))
-	    {
-	      if (PREDICT_FALSE
-		  (current_b0->flags & VLIB_BUFFER_NEXT_PRESENT))
-		{
-		  current_b0 = vlib_get_buffer (vm, current_b0->next_buffer);
-		  bytes_left = current_b0->current_length;
-		}
-	      else
-		{
-		  /* End of packet */
-		  break;
-		}
-	    }
-	}
-
-      /* Move from available to used ring */
-      total_desc_len += desc_len;
-      rxvq->packed_desc[desc_head].len = total_desc_len;
-
-      vhost_user_advance_last_avail_table_idx (vui, rxvq, chained);
-      n_descs_processed++;
-
-      if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
-	cpu->current_trace->hdr = cpu->tx_headers[tx_headers_len - 1];
-
-      n_left--;
-
-      /*
-       * Do the copy periodically to prevent
-       * cpu->copy array overflow and corrupt memory
-       */
-      if (PREDICT_FALSE (copy_len >= VHOST_USER_TX_COPY_THRESHOLD) || chained)
-	{
-	  if (PREDICT_FALSE (vhost_user_tx_copy (vui, cpu->copy, copy_len,
-						 &map_hint)))
-	    vlib_error_count (vm, node->node_index,
-			      VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL, 1);
-	  copy_len = 0;
-
-	  /* give buffers back to driver */
-	  vhost_user_mark_desc_available (vm, vui, rxvq, &n_descs_processed,
-					  chained, frame, n_left);
-	}
-
-      buffers++;
-    }
-
-done:
-  if (PREDICT_TRUE (copy_len))
-    {
-      if (PREDICT_FALSE (vhost_user_tx_copy (vui, cpu->copy, copy_len,
-					     &map_hint)))
-	vlib_error_count (vm, node->node_index,
-			  VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL, 1);
-
-      vhost_user_mark_desc_available (vm, vui, rxvq, &n_descs_processed,
-				      chained, frame, n_left);
-    }
-
-  /*
-   * When n_left is set, error is always set to something too.
-   * In case error is due to lack of remaining buffers, we go back up and
-   * retry.
-   * The idea is that it is better to waste some time on packets
-   * that have been processed already than dropping them and get
-   * more fresh packets with a good likelyhood that they will be dropped too.
-   * This technique also gives more time to VM driver to pick-up packets.
-   * In case the traffic flows from physical to virtual interfaces, this
-   * technique will end-up leveraging the physical NIC buffer in order to
-   * absorb the VM's CPU jitter.
-   */
-  if (n_left && (error == VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF) && retry)
-    {
-      retry--;
-      goto retry;
-    }
-
-  clib_spinlock_unlock (&rxvq->vring_lock);
-
-  if (PREDICT_FALSE (n_left && error != VHOST_USER_TX_FUNC_ERROR_NONE))
-    {
-      vlib_error_count (vm, node->node_index, error, n_left);
-      vlib_increment_simple_counter
-	(vnet_main.interface_main.sw_if_counters +
-	 VNET_INTERFACE_COUNTER_DROP, thread_index, vui->sw_if_index, n_left);
-    }
-
-  vlib_buffer_free (vm, vlib_frame_vector_args (frame), frame->n_vectors);
-  return frame->n_vectors;
-}
-
-VNET_DEVICE_CLASS_TX_FN (vhost_user_device_class) (vlib_main_t * vm,
-						   vlib_node_runtime_t *
-						   node, vlib_frame_t * frame)
-{
-  u32 *buffers = vlib_frame_vector_args (frame);
-  u32 n_left = frame->n_vectors;
-  vhost_user_main_t *vum = &vhost_user_main;
-  vnet_interface_output_runtime_t *rd = (void *) node->runtime_data;
-  vhost_user_intf_t *vui =
-    pool_elt_at_index (vum->vhost_user_interfaces, rd->dev_instance);
-  u32 qid;
-  vhost_user_vring_t *rxvq;
-  u8 error;
-  u32 thread_index = vm->thread_index;
-  vhost_cpu_t *cpu = &vum->cpus[thread_index];
-  u32 map_hint = 0;
-  u8 retry = 8;
-  u16 copy_len;
-  u16 tx_headers_len;
-  u32 or_flags;
-  vnet_hw_if_tx_frame_t *tf = vlib_frame_scalar_args (frame);
-
-  if (PREDICT_FALSE (!vui->admin_up))
-    {
-      error = VHOST_USER_TX_FUNC_ERROR_DOWN;
-      goto done3;
-    }
-
-  if (PREDICT_FALSE (!vui->is_ready))
-    {
-      error = VHOST_USER_TX_FUNC_ERROR_NOT_READY;
-      goto done3;
-    }
-
-  qid = VHOST_VRING_IDX_RX (tf->queue_id);
-  rxvq = &vui->vrings[qid];
-  ASSERT (tf->queue_id == rxvq->qid);
-
-  if (PREDICT_FALSE (rxvq->avail == 0))
-    {
-      error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
-      goto done3;
-    }
-  if (tf->shared_queue)
-    clib_spinlock_lock (&rxvq->vring_lock);
-
-  if (vhost_user_is_packed_ring_supported (vui))
-    return (vhost_user_device_class_packed (vm, node, frame, vui, rxvq));
-
-retry:
-  error = VHOST_USER_TX_FUNC_ERROR_NONE;
-  tx_headers_len = 0;
-  copy_len = 0;
-  while (n_left > 0)
-    {
-      vlib_buffer_t *b0, *current_b0;
-      u16 desc_head, desc_index, desc_len;
-      vnet_virtio_vring_desc_t *desc_table;
-      uword buffer_map_addr;
-      u32 buffer_len;
-      u16 bytes_left;
-
-      if (PREDICT_TRUE (n_left > 1))
-	vlib_prefetch_buffer_with_index (vm, buffers[1], LOAD);
-
-      b0 = vlib_get_buffer (vm, buffers[0]);
-
-      if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
-	{
-	  cpu->current_trace = vlib_add_trace (vm, node, b0,
-					       sizeof (*cpu->current_trace));
-	  vhost_user_tx_trace (cpu->current_trace, vui, qid / 2, b0, rxvq);
-	}
-
-      if (PREDICT_FALSE (rxvq->last_avail_idx == rxvq->avail->idx))
-	{
-	  error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
-	  goto done;
-	}
-
-      desc_table = rxvq->desc;
-      desc_head = desc_index =
-	rxvq->avail->ring[rxvq->last_avail_idx & rxvq->qsz_mask];
-
-      /* Go deeper in case of indirect descriptor
-       * I don't know of any driver providing indirect for RX. */
-      if (PREDICT_FALSE (rxvq->desc[desc_head].flags & VRING_DESC_F_INDIRECT))
-	{
-	  if (PREDICT_FALSE (rxvq->desc[desc_head].len <
-			     sizeof (vnet_virtio_vring_desc_t)))
-	    {
-	      error = VHOST_USER_TX_FUNC_ERROR_INDIRECT_OVERFLOW;
-	      goto done;
-	    }
-	  if (PREDICT_FALSE
-	      (!(desc_table =
-		 map_guest_mem (vui, rxvq->desc[desc_index].addr,
-				&map_hint))))
-	    {
-	      error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
-	      goto done;
-	    }
-	  desc_index = 0;
-	}
-
-      desc_len = vui->virtio_net_hdr_sz;
-      buffer_map_addr = desc_table[desc_index].addr;
-      buffer_len = desc_table[desc_index].len;
-
-      {
-	// Get a header from the header array
-	vnet_virtio_net_hdr_mrg_rxbuf_t *hdr =
-	  &cpu->tx_headers[tx_headers_len];
-	tx_headers_len++;
-	hdr->hdr.flags = 0;
-	hdr->hdr.gso_type = VIRTIO_NET_HDR_GSO_NONE;
-	hdr->num_buffers = 1;	//This is local, no need to check
-
-	or_flags = (b0->flags & VNET_BUFFER_F_OFFLOAD);
-
-	/* Guest supports csum offload and buffer requires checksum offload? */
-	if (or_flags
-	    && (vui->features & VIRTIO_FEATURE (VIRTIO_NET_F_GUEST_CSUM)))
-	  vhost_user_handle_tx_offload (vui, b0, &hdr->hdr);
-
-	// Prepare a copy order executed later for the header
-	ASSERT (copy_len < VHOST_USER_COPY_ARRAY_N);
-	vhost_copy_t *cpy = &cpu->copy[copy_len];
-	copy_len++;
-	cpy->len = vui->virtio_net_hdr_sz;
-	cpy->dst = buffer_map_addr;
-	cpy->src = (uword) hdr;
-      }
-
-      buffer_map_addr += vui->virtio_net_hdr_sz;
-      buffer_len -= vui->virtio_net_hdr_sz;
-      bytes_left = b0->current_length;
-      current_b0 = b0;
-      while (1)
-	{
-	  if (buffer_len == 0)
-	    {			//Get new output
-	      if (desc_table[desc_index].flags & VRING_DESC_F_NEXT)
-		{
-		  //Next one is chained
-		  desc_index = desc_table[desc_index].next;
-		  buffer_map_addr = desc_table[desc_index].addr;
-		  buffer_len = desc_table[desc_index].len;
-		}
-	      else if (vui->virtio_net_hdr_sz == 12)	//MRG is available
-		{
-		  vnet_virtio_net_hdr_mrg_rxbuf_t *hdr =
-		    &cpu->tx_headers[tx_headers_len - 1];
-
-		  //Move from available to used buffer
-		  rxvq->used->ring[rxvq->last_used_idx & rxvq->qsz_mask].id =
-		    desc_head;
-		  rxvq->used->ring[rxvq->last_used_idx & rxvq->qsz_mask].len =
-		    desc_len;
-		  vhost_user_log_dirty_ring (vui, rxvq,
-					     ring[rxvq->last_used_idx &
-						  rxvq->qsz_mask]);
-
-		  rxvq->last_avail_idx++;
-		  rxvq->last_used_idx++;
-		  hdr->num_buffers++;
-		  desc_len = 0;
-
-		  if (PREDICT_FALSE
-		      (rxvq->last_avail_idx == rxvq->avail->idx))
-		    {
-		      //Dequeue queued descriptors for this packet
-		      rxvq->last_used_idx -= hdr->num_buffers - 1;
-		      rxvq->last_avail_idx -= hdr->num_buffers - 1;
-		      error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF;
-		      goto done;
-		    }
-
-		  desc_table = rxvq->desc;
-		  desc_head = desc_index =
-		    rxvq->avail->ring[rxvq->last_avail_idx & rxvq->qsz_mask];
-		  if (PREDICT_FALSE
-		      (rxvq->desc[desc_head].flags & VRING_DESC_F_INDIRECT))
-		    {
-		      //It is seriously unlikely that a driver will put indirect descriptor
-		      //after non-indirect descriptor.
-		      if (PREDICT_FALSE (rxvq->desc[desc_head].len <
-					 sizeof (vnet_virtio_vring_desc_t)))
-			{
-			  error = VHOST_USER_TX_FUNC_ERROR_INDIRECT_OVERFLOW;
-			  goto done;
-			}
-		      if (PREDICT_FALSE
-			  (!(desc_table =
-			     map_guest_mem (vui,
-					    rxvq->desc[desc_index].addr,
-					    &map_hint))))
-			{
-			  error = VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL;
-			  goto done;
-			}
-		      desc_index = 0;
-		    }
-		  buffer_map_addr = desc_table[desc_index].addr;
-		  buffer_len = desc_table[desc_index].len;
-		}
-	      else
-		{
-		  error = VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOMRG;
-		  goto done;
-		}
-	    }
-
-	  {
-	    ASSERT (copy_len < VHOST_USER_COPY_ARRAY_N);
-	    vhost_copy_t *cpy = &cpu->copy[copy_len];
-	    copy_len++;
-	    cpy->len = bytes_left;
-	    cpy->len = (cpy->len > buffer_len) ? buffer_len : cpy->len;
-	    cpy->dst = buffer_map_addr;
-	    cpy->src = (uword) vlib_buffer_get_current (current_b0) +
-	      current_b0->current_length - bytes_left;
-
-	    bytes_left -= cpy->len;
-	    buffer_len -= cpy->len;
-	    buffer_map_addr += cpy->len;
-	    desc_len += cpy->len;
-
-	    clib_prefetch_load (&rxvq->desc);
-	  }
-
-	  // Check if vlib buffer has more data. If not, get more or break.
-	  if (PREDICT_TRUE (!bytes_left))
-	    {
-	      if (PREDICT_FALSE
-		  (current_b0->flags & VLIB_BUFFER_NEXT_PRESENT))
-		{
-		  current_b0 = vlib_get_buffer (vm, current_b0->next_buffer);
-		  bytes_left = current_b0->current_length;
-		}
-	      else
-		{
-		  //End of packet
-		  break;
-		}
-	    }
-	}
-
-      //Move from available to used ring
-      rxvq->used->ring[rxvq->last_used_idx & rxvq->qsz_mask].id = desc_head;
-      rxvq->used->ring[rxvq->last_used_idx & rxvq->qsz_mask].len = desc_len;
-      vhost_user_log_dirty_ring (vui, rxvq,
-				 ring[rxvq->last_used_idx & rxvq->qsz_mask]);
-      rxvq->last_avail_idx++;
-      rxvq->last_used_idx++;
-
-      if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
-	{
-	  cpu->current_trace->hdr = cpu->tx_headers[tx_headers_len - 1];
-	}
-
-      n_left--;			//At the end for error counting when 'goto done' is invoked
-
-      /*
-       * Do the copy periodically to prevent
-       * cpu->copy array overflow and corrupt memory
-       */
-      if (PREDICT_FALSE (copy_len >= VHOST_USER_TX_COPY_THRESHOLD))
-	{
-	  if (PREDICT_FALSE (vhost_user_tx_copy (vui, cpu->copy, copy_len,
-						 &map_hint)))
-	    {
-	      vlib_error_count (vm, node->node_index,
-				VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL, 1);
-	    }
-	  copy_len = 0;
-
-	  /* give buffers back to driver */
-	  CLIB_MEMORY_BARRIER ();
-	  rxvq->used->idx = rxvq->last_used_idx;
-	  vhost_user_log_dirty_ring (vui, rxvq, idx);
-	}
-      buffers++;
-    }
-
-done:
-  //Do the memory copies
-  if (PREDICT_FALSE (vhost_user_tx_copy (vui, cpu->copy, copy_len,
-					 &map_hint)))
-    {
-      vlib_error_count (vm, node->node_index,
-			VHOST_USER_TX_FUNC_ERROR_MMAP_FAIL, 1);
-    }
-
-  CLIB_MEMORY_BARRIER ();
-  rxvq->used->idx = rxvq->last_used_idx;
-  vhost_user_log_dirty_ring (vui, rxvq, idx);
-
-  /*
-   * When n_left is set, error is always set to something too.
-   * In case error is due to lack of remaining buffers, we go back up and
-   * retry.
-   * The idea is that it is better to waste some time on packets
-   * that have been processed already than dropping them and get
-   * more fresh packets with a good likelihood that they will be dropped too.
-   * This technique also gives more time to VM driver to pick-up packets.
-   * In case the traffic flows from physical to virtual interfaces, this
-   * technique will end-up leveraging the physical NIC buffer in order to
-   * absorb the VM's CPU jitter.
-   */
-  if (n_left && (error == VHOST_USER_TX_FUNC_ERROR_PKT_DROP_NOBUF) && retry)
-    {
-      retry--;
-      goto retry;
-    }
-
-  /* interrupt (call) handling */
-  if ((rxvq->callfd_idx != ~0) &&
-      !(rxvq->avail->flags & VRING_AVAIL_F_NO_INTERRUPT))
-    {
-      rxvq->n_since_last_int += frame->n_vectors - n_left;
-
-      if (rxvq->n_since_last_int > vum->coalesce_frames)
-	vhost_user_send_call (vm, vui, rxvq);
-    }
-
-  clib_spinlock_unlock (&rxvq->vring_lock);
-
-done3:
-  if (PREDICT_FALSE (n_left && error != VHOST_USER_TX_FUNC_ERROR_NONE))
-    {
-      vlib_error_count (vm, node->node_index, error, n_left);
-      vlib_increment_simple_counter
-	(vnet_main.interface_main.sw_if_counters
-	 + VNET_INTERFACE_COUNTER_DROP,
-	 thread_index, vui->sw_if_index, n_left);
-    }
-
-  vlib_buffer_free (vm, vlib_frame_vector_args (frame), frame->n_vectors);
-  return frame->n_vectors;
-}
-
-static __clib_unused clib_error_t *
-vhost_user_interface_rx_mode_change (vnet_main_t * vnm, u32 hw_if_index,
-				     u32 qid, vnet_hw_if_rx_mode mode)
-{
-  vlib_main_t *vm = vnm->vlib_main;
-  vnet_hw_interface_t *hif = vnet_get_hw_interface (vnm, hw_if_index);
-  vhost_user_main_t *vum = &vhost_user_main;
-  vhost_user_intf_t *vui =
-    pool_elt_at_index (vum->vhost_user_interfaces, hif->dev_instance);
-  vhost_user_vring_t *txvq = &vui->vrings[VHOST_VRING_IDX_TX (qid)];
-  vhost_cpu_t *cpu;
-
-  if (mode == txvq->mode)
-    return 0;
-
-  if ((mode != VNET_HW_IF_RX_MODE_POLLING) &&
-      (mode != VNET_HW_IF_RX_MODE_ADAPTIVE) &&
-      (mode != VNET_HW_IF_RX_MODE_INTERRUPT))
-    {
-      vu_log_err (vui, "unhandled mode %d changed for if %d queue %d", mode,
-		  hw_if_index, qid);
-      return clib_error_return (0, "unsupported");
-    }
-
-  if (txvq->thread_index == ~0)
-    return clib_error_return (0, "Queue initialization is not finished yet");
-
-  cpu = vec_elt_at_index (vum->cpus, txvq->thread_index);
-  if ((mode == VNET_HW_IF_RX_MODE_INTERRUPT) ||
-      (mode == VNET_HW_IF_RX_MODE_ADAPTIVE))
-    {
-      if (txvq->kickfd_idx == ~0)
-	{
-	  // We cannot support interrupt mode if the driver opts out
-	  return clib_error_return (0, "Driver does not support interrupt");
-	}
-      if (txvq->mode == VNET_HW_IF_RX_MODE_POLLING)
-	{
-	  ASSERT (cpu->polling_q_count != 0);
-	  if (cpu->polling_q_count)
-	    cpu->polling_q_count--;
-	  vum->ifq_count++;
-	  // Start the timer if this is the first encounter on interrupt
-	  // interface/queue
-	  if ((vum->ifq_count == 1) &&
-	      ((vum->coalesce_time > 0.0) || (vum->coalesce_frames > 0)))
-	    vlib_process_signal_event (vm,
-				       vhost_user_send_interrupt_node.index,
-				       VHOST_USER_EVENT_START_TIMER, 0);
-	}
-    }
-  else if (mode == VNET_HW_IF_RX_MODE_POLLING)
-    {
-      if (((txvq->mode == VNET_HW_IF_RX_MODE_INTERRUPT) ||
-	   (txvq->mode == VNET_HW_IF_RX_MODE_ADAPTIVE)) && vum->ifq_count)
-	{
-	  cpu->polling_q_count++;
-	  vum->ifq_count--;
-	  // Stop the timer if there is no more interrupt interface/queue
-	  if (vum->ifq_count == 0)
-	    vlib_process_signal_event (vm,
-				       vhost_user_send_interrupt_node.index,
-				       VHOST_USER_EVENT_STOP_TIMER, 0);
-	}
-    }
-
-  txvq->mode = mode;
-  vhost_user_set_operation_mode (vui, txvq);
-
-  return 0;
-}
-
-static __clib_unused clib_error_t *
-vhost_user_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);
-  vhost_user_main_t *vum = &vhost_user_main;
-  vhost_user_intf_t *vui =
-    pool_elt_at_index (vum->vhost_user_interfaces, hif->dev_instance);
-  u8 link_old, link_new;
-
-  link_old = vui_is_link_up (vui);
-
-  vui->admin_up = (flags & VNET_SW_INTERFACE_FLAG_ADMIN_UP) != 0;
-
-  link_new = vui_is_link_up (vui);
-
-  if (link_old != link_new)
-    vnet_hw_interface_set_flags (vnm, vui->hw_if_index, link_new ?
-				 VNET_HW_INTERFACE_FLAG_LINK_UP : 0);
-
-  return /* no error */ 0;
-}
-
-/* *INDENT-OFF* */
-VNET_DEVICE_CLASS (vhost_user_device_class) = {
-  .name = "vhost-user",
-  .tx_function_n_errors = VHOST_USER_TX_FUNC_N_ERROR,
-  .tx_function_error_strings = vhost_user_tx_func_error_strings,
-  .format_device_name = format_vhost_user_interface_name,
-  .name_renumber = vhost_user_name_renumber,
-  .admin_up_down_function = vhost_user_interface_admin_up_down,
-  .rx_mode_change_function = vhost_user_interface_rx_mode_change,
-  .format_tx_trace = format_vhost_trace,
-};
-
-/* *INDENT-ON* */
-
-/*
- * fd.io coding-style-patch-verification: ON
- *
- * Local Variables:
- * eval: (c-set-style "gnu")
- * End:
- */