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# Copyright (c) 2021 Cisco and/or its affiliates.
#
# SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later
#
# Licensed under the Apache License 2.0 or
# GNU General Public License v2.0 or later;  you may not use this file
# except in compliance with one of these Licenses. You
# may obtain a copy of the Licenses at:
#
#     http://www.apache.org/licenses/LICENSE-2.0
#     https://www.gnu.org/licenses/old-licenses/gpl-2.0-standalone.html
#
# Note: If this file is linked with Scapy, which is GPLv2+, your use of it
# must be under GPLv2+.  If at any point in the future it is no longer linked
# with Scapy (or other GPLv2+ licensed software), you are free to choose
# Apache 2.
#
# 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.

"""Traffic profile for T-rex advanced stateful (astf) traffic generator.

Traffic profile:
 - Two streams sent in directions 0 --> 1 (client -> server, requests) and
   1 --> 0 (server -> client, responses) at the same time.
 - Packet: ETH / IP / UDP
 - Direction 0 --> 1:
   - Source IP address range:      192.168.0.0 - 192.168.63.255
   - Destination IP address range: 20.0.0.0 - 20.0.63.255
 - Direction 1 --> 0:
   - Source IP address range:      destination IP address from packet received
     on port 1
   - Destination IP address range: source IP address from packet received
     on port 1

This is a profile for CPS tests, it only sets up UDP session.
No delays, no data transfer.
Keepalive mechanism cannot be disabled, so it is at least set to long waits.
"""

from trex.astf.api import *

from profile_trex_astf_base_class import TrafficProfileBaseClass


class TrafficProfile(TrafficProfileBaseClass):
    """Traffic profile."""

    def __init__(self):
        """Initialization and setting of profile parameters."""

        super(TrafficProfileBaseClass, self).__init__()

        # IPs used in packet headers.
        self.p1_src_start_ip = u"192.168.0.0"
        self.p1_src_end_ip = u"192.168.63.255"
        self.p1_dst_start_ip = u"20.0.0.0"
        self.p1_dst_end_ip = u"20.0.63.255"

        # UDP messages
        self.udp_req = u"GET"
        self.udp_res = u"ACK"

        # Headers length
        self.headers_size = 42  # 14B l2 + 20B ipv4 + 8B udp

        # No need to set keepalive, both programs end just after start&send.

    def define_profile(self):
        """Define profile to be used by advanced stateful traffic generator.

        This method MUST return:
            return ip_gen, templates, None

        :returns: IP generator and profile templates ASTFProfile().
        :rtype: tuple
        """
        self.udp_req += self._gen_padding(self.headers_size + len(self.udp_req))
        self.udp_res += self._gen_padding(self.headers_size + len(self.udp_res))

        # client commands
        prog_c = ASTFProgram(stream=False)
        # send REQ message
        prog_c.send_msg(self.udp_req)
        # No need to process the response, seeing L2 counter is enough.
        # Client program can end here.

        # server commands
        prog_s = ASTFProgram(stream=False)
        # When server instance is created means REQ is visible in L2 counter.
        # No need to receive explicitly?
        # send RES message
        prog_s.send_msg(self.udp_res)
        # Server program can end here.

        # ip generators
        ip_gen_c = ASTFIPGenDist(
            ip_range=[self.p1_src_start_ip, self.p1_src_end_ip],
            distribution=u"seq"
        )
        ip_gen_s = ASTFIPGenDist(
            ip_range=[self.p1_dst_start_ip, self.p1_dst_end_ip],
            distribution=u"seq"
        )
        ip_gen = ASTFIPGen(
            glob=ASTFIPGenGlobal(ip_offset=u"0.0.0.1"),
            dist_client=ip_gen_c,
            dist_server=ip_gen_s
        )

        # server association
        s_assoc = ASTFAssociation(rules=ASTFAssociationRule(port=8080))

        # template
        temp_c = ASTFTCPClientTemplate(
            program=prog_c,
            ip_gen=ip_gen,
            limit=1032192,  # TODO: set via input parameter ?
            port=8080
        )
        temp_s = ASTFTCPServerTemplate(program=prog_s, assoc=s_assoc)
        template = ASTFTemplate(client_template=temp_c, server_template=temp_s)

        return ip_gen, template, None


def register():
    """Register this traffic profile to T-Rex.

    Do not change this function.

    :return: Traffic Profiles.
    :rtype: Object
    """
    return TrafficProfile()
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/*
 *------------------------------------------------------------------
 * 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/ethernet/ethernet.h>
#include <vnet/devices/devices.h>
#include <vnet/feature/feature.h>
#include <vnet/udp/udp_packet.h>
#include <vnet/tcp/tcp_packet.h>
#include <vnet/interface/rx_queue_funcs.h>

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

#include <vnet/ip/ip4_packet.h>
#include <vnet/ip/ip6_packet.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

extern 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)") \
  _(NOT_READY, "vhost interface not ready or down") \
  _(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,
		     u16 last_avail_idx)
{
  vhost_user_main_t *vum = &vhost_user_main;
  u32 desc_current = txvq->avail->ring[last_avail_idx & txvq->qsz_mask];
  vnet_virtio_vring_desc_t *hdr_desc = 0;
  vnet_virtio_net_hdr_mrg_rxbuf_t *hdr;
  u32 hint = 0;

  clib_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 & VRING_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 & VRING_DESC_F_NEXT)
    {
      t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SIMPLE_CHAINED;
    }
  if (!(txvq->desc[desc_current].flags & VRING_DESC_F_NEXT) &&
      !(txvq->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;

  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_load (src2);
	  clib_prefetch_load (src3);

	  clib_memcpy_fast ((void *) cpy[0].dst, src0, cpy[0].len);
	  clib_memcpy_fast ((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_fast ((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;
  u16 mask = txvq->qsz_mask;
  u16 last_avail_idx = txvq->last_avail_idx;
  u16 last_used_idx = txvq->last_used_idx;
  while (discarded_packets != discard_max)
    {
      if (avail_idx == last_avail_idx)
	goto out;

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

out:
  txvq->last_avail_idx = last_avail_idx;
  txvq->last_used_idx = last_used_idx;
  CLIB_MEMORY_STORE_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_always_inline 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_always_inline void
vhost_user_handle_rx_offload (vlib_buffer_t *b0, u8 *b0_data,
			      vnet_virtio_net_hdr_t *hdr)
{
  u8 l4_hdr_sz = 0;
  u8 l4_proto = 0;
  ethernet_header_t *eh = (ethernet_header_t *) b0_data;
  u16 ethertype = clib_net_to_host_u16 (eh->type);
  u16 l2hdr_sz = sizeof (ethernet_header_t);
  vnet_buffer_oflags_t oflags = 0;

  if (ethernet_frame_is_tagged (ethertype))
    {
      ethernet_vlan_header_t *vlan = (ethernet_vlan_header_t *) (eh + 1);

      ethertype = clib_net_to_host_u16 (vlan->type);
      l2hdr_sz += sizeof (*vlan);
      if (ethertype == ETHERNET_TYPE_VLAN)
	{
	  vlan++;
	  ethertype = clib_net_to_host_u16 (vlan->type);
	  l2hdr_sz += sizeof (*vlan);
	}
    }
  vnet_buffer (b0)->l2_hdr_offset = 0;
  vnet_buffer (b0)->l3_hdr_offset = l2hdr_sz;
  vnet_buffer (b0)->l4_hdr_offset = hdr->csum_start;
  b0->flags |= (VNET_BUFFER_F_L2_HDR_OFFSET_VALID |
		VNET_BUFFER_F_L3_HDR_OFFSET_VALID |
		VNET_BUFFER_F_L4_HDR_OFFSET_VALID);

  if (PREDICT_TRUE (ethertype == ETHERNET_TYPE_IP4))
    {
      ip4_header_t *ip4 = (ip4_header_t *) (b0_data + l2hdr_sz);
      l4_proto = ip4->protocol;
      b0->flags |= VNET_BUFFER_F_IS_IP4;
      oflags |= VNET_BUFFER_OFFLOAD_F_IP_CKSUM;
    }
  else if (PREDICT_TRUE (ethertype == ETHERNET_TYPE_IP6))
    {
      ip6_header_t *ip6 = (ip6_header_t *) (b0_data + l2hdr_sz);
      l4_proto = ip6->protocol;
      b0->flags |= VNET_BUFFER_F_IS_IP6;
    }

  if (l4_proto == IP_PROTOCOL_TCP)
    {
      tcp_header_t *tcp = (tcp_header_t *)
	(b0_data + vnet_buffer (b0)->l4_hdr_offset);
      l4_hdr_sz = tcp_header_bytes (tcp);
      oflags |= VNET_BUFFER_OFFLOAD_F_TCP_CKSUM;
    }
  else if (l4_proto == IP_PROTOCOL_UDP)
    {
      l4_hdr_sz = sizeof (udp_header_t);
      oflags |= VNET_BUFFER_OFFLOAD_F_UDP_CKSUM;
    }

  if (hdr->gso_type == VIRTIO_NET_HDR_GSO_UDP)
    {
      vnet_buffer2 (b0)->gso_size = hdr->gso_size;
      vnet_buffer2 (b0)->gso_l4_hdr_sz = l4_hdr_sz;
      b0->flags |= VNET_BUFFER_F_GSO;
    }
  else if (hdr->gso_type == VIRTIO_NET_HDR_GSO_TCPV4)
    {
      vnet_buffer2 (b0)->gso_size = hdr->gso_size;
      vnet_buffer2 (b0)->gso_l4_hdr_sz = l4_hdr_sz;
      b0->flags |= (VNET_BUFFER_F_GSO | VNET_BUFFER_F_IS_IP4);
    }
  else if (hdr->gso_type == VIRTIO_NET_HDR_GSO_TCPV6)
    {
      vnet_buffer2 (b0)->gso_size = hdr->gso_size;
      vnet_buffer2 (b0)->gso_l4_hdr_sz = l4_hdr_sz;
      b0->flags |= (VNET_BUFFER_F_GSO | VNET_BUFFER_F_IS_IP6);
    }

  if (oflags)
    vnet_buffer_offload_flags_set (b0, oflags);
}

static_always_inline void
vhost_user_input_do_interrupt (vlib_main_t * vm, vhost_user_intf_t * vui,
			       vhost_user_vring_t * txvq,
			       vhost_user_vring_t * rxvq)
{
  f64 now = vlib_time_now (vm);

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

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

static_always_inline void
vhost_user_input_setup_frame (vlib_main_t * vm, vlib_node_runtime_t * node,
			      vhost_user_intf_t * vui,
			      u32 * current_config_index, u32 * next_index,
			      u32 ** to_next, u32 * n_left_to_next)
{
  vnet_feature_main_t *fm = &feature_main;
  u8 feature_arc_idx = fm->device_input_feature_arc_index;

  if (PREDICT_FALSE (vnet_have_features (feature_arc_idx, vui->sw_if_index)))
    {
      vnet_feature_config_main_t *cm;
      cm = &fm->feature_config_mains[feature_arc_idx];
      *current_config_index = vec_elt (cm->config_index_by_sw_if_index,
				       vui->sw_if_index);
      vnet_get_config_data (&cm->config_main, current_config_index,
			    next_index, 0);
    }

  vlib_get_new_next_frame (vm, node, *next_index, *to_next, *n_left_to_next);

  if (*next_index == VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT)
    {
      /* give some hints to ethernet-input */
      vlib_next_frame_t *nf;
      vlib_frame_t *f;
      ethernet_input_frame_t *ef;
      nf = vlib_node_runtime_get_next_frame (vm, node, *next_index);
      f = vlib_get_frame (vm, nf->frame);
      f->flags = ETH_INPUT_FRAME_F_SINGLE_SW_IF_IDX;

      ef = vlib_frame_scalar_args (f);
      ef->sw_if_index = vui->sw_if_index;
      ef->hw_if_index = vui->hw_if_index;
      vlib_frame_no_append (f);
    }
}

static_always_inline 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, u8 enable_csum)
{
  vhost_user_vring_t *txvq = &vui->vrings[VHOST_VRING_IDX_TX (qid)];
  vnet_feature_main_t *fm = &feature_main;
  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 buffer_data_size = vlib_buffer_get_default_data_size (vm);
  u32 map_hint = 0;
  vhost_cpu_t *cpu = &vum->cpus[vm->thread_index];
  u16 copy_len = 0;
  u8 feature_arc_idx = fm->device_input_feature_arc_index;
  u32 current_config_index = ~(u32) 0;
  u16 mask = txvq->qsz_mask;

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

  {
    /* do we have pending interrupts ? */
    vhost_user_vring_t *rxvq = &vui->vrings[VHOST_VRING_IDX_RX (qid)];
    vhost_user_input_do_interrupt (vm, vui, txvq, 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 (txvq->mode == VNET_HW_IF_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))
    goto done;

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

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

  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);
      goto done;
    }

  if (PREDICT_FALSE (n_left == (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 yield 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 (cpu->rx_buffers_len < n_left + 1 ||
		     cpu->rx_buffers_len < 40))
    {
      u32 curr_len = cpu->rx_buffers_len;
      cpu->rx_buffers_len +=
	vlib_buffer_alloc (vm, cpu->rx_buffers + curr_len,
			   VHOST_USER_RX_BUFFERS_N - curr_len);

      if (PREDICT_FALSE
	  (cpu->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 > cpu->rx_buffers_len) ?
	    n_left + 1 - cpu->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,
					 vm->thread_index, vui->sw_if_index,
					 flush);

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

  vhost_user_input_setup_frame (vm, node, vui, &current_config_index,
				&next_index, &to_next, &n_left_to_next);

  u16 last_avail_idx = txvq->last_avail_idx;
  u16 last_used_idx = txvq->last_used_idx;

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

      if (PREDICT_FALSE (cpu->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[last_avail_idx & mask];
      cpu->rx_buffers_len--;
      bi_current = cpu->rx_buffers[cpu->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, cpu->rx_buffers[cpu->rx_buffers_len - 1], LOAD);

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

      desc_data_offset = vui->virtio_net_hdr_sz;

      if (enable_csum)
	{
	  vnet_virtio_net_hdr_mrg_rxbuf_t *hdr;
	  u8 *b_data;
	  u16 current;

	  hdr = map_guest_mem (vui, desc_table[desc_current].addr, &map_hint);
	  if (PREDICT_FALSE (hdr == 0))
	    {
	      vlib_error_count (vm, node->node_index,
				VHOST_USER_INPUT_FUNC_ERROR_MMAP_FAIL, 1);
	      goto out;
	    }
	  if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
	    {
	      if ((desc_data_offset == desc_table[desc_current].len) &&
		  (desc_table[desc_current].flags & VRING_DESC_F_NEXT))
		{
		  current = desc_table[desc_current].next;
		  b_data = map_guest_mem (vui, desc_table[current].addr,
					  &map_hint);
		  if (PREDICT_FALSE (b_data == 0))
		    {
		      vlib_error_count (vm, node->node_index,
					VHOST_USER_INPUT_FUNC_ERROR_MMAP_FAIL,
					1);
		      goto out;
		    }
		}
	      else
		b_data = (u8 *) hdr + desc_data_offset;

	      vhost_user_handle_rx_offload (b_head, b_data, &hdr->hdr);
	    }
	}

      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 &
				 VRING_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 == buffer_data_size))
	    {
	      if (PREDICT_FALSE (cpu->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, cpu, b_head);
		  n_left = 0;
		  goto stop;
		}

	      /* Get next output */
	      cpu->rx_buffers_len--;
	      u32 bi_next = cpu->rx_buffers[cpu->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 */
	  ASSERT (copy_len < VHOST_USER_COPY_ARRAY_N);
	  vhost_copy_t *cpy = &cpu->copy[copy_len];
	  copy_len++;
	  u32 desc_data_l = desc_table[desc_current].len - desc_data_offset;
	  cpy->len = 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:

      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 */
      last_avail_idx++;
      last_used_idx++;

      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;

      if (current_config_index != ~(u32) 0)
	{
	  b_head->current_config_index = current_config_index;
	  vnet_buffer (b_head)->feature_arc_index = feature_arc_idx;
	}

      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, cpu->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_STORE_BARRIER ();
	  txvq->used->idx = last_used_idx;
	  vhost_user_log_dirty_ring (vui, txvq, idx);
	}
    }
stop:
  vlib_put_next_frame (vm, node, next_index, n_left_to_next);

  txvq->last_used_idx = last_used_idx;
  txvq->last_avail_idx = last_avail_idx;

  /* Do the memory copies */
  if (PREDICT_FALSE (vhost_user_input_copy (vui, cpu->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_STORE_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, vui, txvq);
    }

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

  vnet_device_increment_rx_packets (vm->thread_index, n_rx_packets);

done:
  return n_rx_packets;
}

static_always_inline void
vhost_user_mark_desc_consumed (vhost_user_intf_t * vui,
			       vhost_user_vring_t * txvq, u16 desc_head,
			       u16 n_descs_processed)
{
  vnet_virtio_vring_packed_desc_t *desc_table = txvq->packed_desc;
  u16 desc_idx;
  u16 mask = txvq->qsz_mask;

  for (desc_idx = 0; desc_idx < n_descs_processed; desc_idx++)
    {
      if (txvq->used_wrap_counter)
	desc_table[(desc_head + desc_idx) & mask].flags |=
	  (VRING_DESC_F_AVAIL | VRING_DESC_F_USED);
      else
	desc_table[(desc_head + desc_idx) & mask].flags &=
	  ~(VRING_DESC_F_AVAIL | VRING_DESC_F_USED);
      vhost_user_advance_last_used_idx (txvq);
    }
}

static_always_inline void
vhost_user_rx_trace_packed (vhost_trace_t * t, vhost_user_intf_t * vui,
			    u16 qid, vhost_user_vring_t * txvq,
			    u16 desc_current)
{
  vhost_user_main_t *vum = &vhost_user_main;
  vnet_virtio_vring_packed_desc_t *hdr_desc;
  vnet_virtio_net_hdr_mrg_rxbuf_t *hdr;
  u32 hint = 0;

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

  hdr_desc = &txvq->packed_desc[desc_current];
  if (txvq->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, txvq->packed_desc[desc_current].addr,
				&hint);
    }
  if (txvq->packed_desc[desc_current].flags & VRING_DESC_F_NEXT)
    t->virtio_ring_flags |= 1 << VIRTIO_TRACE_F_SIMPLE_CHAINED;

  if (!(txvq->packed_desc[desc_current].flags & VRING_DESC_F_NEXT) &&
      !(txvq->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;

  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;
      clib_memcpy_fast (&t->hdr, hdr,
			len > hdr_desc->len ? hdr_desc->len : len);
    }
}

static_always_inline u32
vhost_user_rx_discard_packet_packed (vlib_main_t * vm,
				     vhost_user_intf_t * vui,
				     vhost_user_vring_t * txvq,
				     u32 discard_max)
{
  u32 discarded_packets = 0;
  u16 mask = txvq->qsz_mask;
  u16 desc_current, desc_head;

  desc_head = desc_current = txvq->last_used_idx & mask;

  /*
   * 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.
   */
  while ((discarded_packets != discard_max) &&
	 vhost_user_packed_desc_available (txvq, desc_current))
    {
      vhost_user_advance_last_avail_idx (txvq);
      discarded_packets++;
      desc_current = (desc_current + 1) & mask;
    }

  if (PREDICT_TRUE (discarded_packets))
    vhost_user_mark_desc_consumed (vui, txvq, desc_head, discarded_packets);
  return (discarded_packets);
}

static_always_inline u32
vhost_user_input_copy_packed (vhost_user_intf_t * vui, vhost_copy_t * cpy,
			      u16 copy_len, u32 * map_hint)
{
  void *src0, *src1, *src2, *src3, *src4, *src5, *src6, *src7;
  u8 bad;
  u32 rc = VHOST_USER_INPUT_FUNC_ERROR_NO_ERROR;

  if (PREDICT_TRUE (copy_len >= 8))
    {
      src4 = map_guest_mem (vui, cpy[0].src, map_hint);
      src5 = map_guest_mem (vui, cpy[1].src, map_hint);
      src6 = map_guest_mem (vui, cpy[2].src, map_hint);
      src7 = map_guest_mem (vui, cpy[3].src, map_hint);
      bad = (src4 == 0) + (src5 == 0) + (src6 == 0) + (src7 == 0);
      if (PREDICT_FALSE (bad))
	goto one_by_one;
      clib_prefetch_load (src4);
      clib_prefetch_load (src5);
      clib_prefetch_load (src6);
      clib_prefetch_load (src7);

      while (PREDICT_TRUE (copy_len >= 8))
	{
	  src0 = src4;
	  src1 = src5;
	  src2 = src6;
	  src3 = src7;

	  src4 = map_guest_mem (vui, cpy[4].src, map_hint);
	  src5 = map_guest_mem (vui, cpy[5].src, map_hint);
	  src6 = map_guest_mem (vui, cpy[6].src, map_hint);
	  src7 = map_guest_mem (vui, cpy[7].src, map_hint);
	  bad = (src4 == 0) + (src5 == 0) + (src6 == 0) + (src7 == 0);
	  if (PREDICT_FALSE (bad))
	    break;

	  clib_prefetch_load (src4);
	  clib_prefetch_load (src5);
	  clib_prefetch_load (src6);
	  clib_prefetch_load (src7);

	  clib_memcpy_fast ((void *) cpy[0].dst, src0, cpy[0].len);
	  clib_memcpy_fast ((void *) cpy[1].dst, src1, cpy[1].len);
	  clib_memcpy_fast ((void *) cpy[2].dst, src2, cpy[2].len);
	  clib_memcpy_fast ((void *) cpy[3].dst, src3, cpy[3].len);
	  copy_len -= 4;
	  cpy += 4;
	}
    }

one_by_one:
  while (copy_len)
    {
      if (PREDICT_FALSE (!(src0 = map_guest_mem (vui, cpy->src, map_hint))))
	{
	  rc = VHOST_USER_INPUT_FUNC_ERROR_MMAP_FAIL;
	  break;
	}
      clib_memcpy_fast ((void *) cpy->dst, src0, cpy->len);
      copy_len -= 1;
      cpy += 1;
    }
  return rc;
}

static_always_inline u32
vhost_user_do_offload (vhost_user_intf_t *vui,
		       vnet_virtio_vring_packed_desc_t *desc_table,
		       u16 desc_current, u16 mask, vlib_buffer_t *b_head,
		       u32 *map_hint)
{
  u32 rc = VHOST_USER_INPUT_FUNC_ERROR_NO_ERROR;
  vnet_virtio_net_hdr_mrg_rxbuf_t *hdr;
  u8 *b_data;
  u32 desc_data_offset = vui->virtio_net_hdr_sz;

  hdr = map_guest_mem (vui, desc_table[desc_current].addr, map_hint);
  if (PREDICT_FALSE (hdr == 0))
    rc = VHOST_USER_INPUT_FUNC_ERROR_MMAP_FAIL;
  else if (hdr->hdr.flags & VIRTIO_NET_HDR_F_NEEDS_CSUM)
    {
      if (desc_data_offset == desc_table[desc_current].len)
	{
	  desc_current = (desc_current + 1) & mask;
	  b_data =
	    map_guest_mem (vui, desc_table[desc_current].addr, map_hint);
	  if (PREDICT_FALSE (b_data == 0))
	    rc = VHOST_USER_INPUT_FUNC_ERROR_MMAP_FAIL;
	  else
	    vhost_user_handle_rx_offload (b_head, b_data, &hdr->hdr);
	}
      else
	{
	  b_data = (u8 *) hdr + desc_data_offset;
	  vhost_user_handle_rx_offload (b_head, b_data, &hdr->hdr);
	}
    }

  return rc;
}

static_always_inline u32
vhost_user_compute_buffers_required (u32 desc_len, u32 buffer_data_size)
{
  div_t result;
  u32 buffers_required;

  if (PREDICT_TRUE (buffer_data_size == 2048))
    {
      buffers_required = desc_len >> 11;
      if ((desc_len & 2047) != 0)
	buffers_required++;
      return (buffers_required);
    }

  if (desc_len < buffer_data_size)
    return 1;

  result = div (desc_len, buffer_data_size);
  if (result.rem)
    buffers_required = result.quot + 1;
  else
    buffers_required = result.quot;

  return (buffers_required);
}

static_always_inline u32
vhost_user_compute_indirect_desc_len (vhost_user_intf_t * vui,
				      vhost_user_vring_t * txvq,
				      u32 buffer_data_size, u16 desc_current,
				      u32 * map_hint)
{
  vnet_virtio_vring_packed_desc_t *desc_table = txvq->packed_desc;
  u32 desc_len = 0;
  u16 desc_data_offset = vui->virtio_net_hdr_sz;
  u16 desc_idx = desc_current;
  u32 n_descs;

  n_descs = desc_table[desc_idx].len >> 4;
  desc_table = map_guest_mem (vui, desc_table[desc_idx].addr, map_hint);
  if (PREDICT_FALSE (desc_table == 0))
    return 0;

  for (desc_idx = 0; desc_idx < n_descs; desc_idx++)
    desc_len += desc_table[desc_idx].len;

  if (PREDICT_TRUE (desc_len > desc_data_offset))
    desc_len -= desc_data_offset;

  return vhost_user_compute_buffers_required (desc_len, buffer_data_size);
}

static_always_inline u32
vhost_user_compute_chained_desc_len (vhost_user_intf_t * vui,
				     vhost_user_vring_t * txvq,
				     u32 buffer_data_size, u16 * current,
				     u16 * n_left)
{
  vnet_virtio_vring_packed_desc_t *desc_table = txvq->packed_desc;
  u32 desc_len = 0;
  u16 mask = txvq->qsz_mask;

  while (desc_table[*current].flags & VRING_DESC_F_NEXT)
    {
      desc_len += desc_table[*current].len;
      (*n_left)++;
      *current = (*current + 1) & mask;
      vhost_user_advance_last_avail_idx (txvq);
    }
  desc_len += desc_table[*current].len;
  (*n_left)++;
  *current = (*current + 1) & mask;
  vhost_user_advance_last_avail_idx (txvq);

  if (PREDICT_TRUE (desc_len > vui->virtio_net_hdr_sz))
    desc_len -= vui->virtio_net_hdr_sz;

  return vhost_user_compute_buffers_required (desc_len, buffer_data_size);
}

static_always_inline void
vhost_user_assemble_packet (vnet_virtio_vring_packed_desc_t *desc_table,
			    u16 *desc_idx, vlib_buffer_t *b_head,
			    vlib_buffer_t **b_current, u32 **next,
			    vlib_buffer_t ***b, u32 *bi_current,
			    vhost_cpu_t *cpu, u16 *copy_len, u32 *buffers_used,
			    u32 buffers_required, u32 *desc_data_offset,
			    u32 buffer_data_size, u16 mask)
{
  u32 desc_data_l;

  while (*desc_data_offset < desc_table[*desc_idx].len)
    {
      /* Get more output if necessary. Or end of packet. */
      if (PREDICT_FALSE ((*b_current)->current_length == buffer_data_size))
	{
	  /* Get next output */
	  u32 bi_next = **next;
	  (*next)++;
	  (*b_current)->next_buffer = bi_next;
	  (*b_current)->flags |= VLIB_BUFFER_NEXT_PRESENT;
	  *bi_current = bi_next;
	  *b_current = **b;
	  (*b)++;
	  (*buffers_used)++;
	  ASSERT (*buffers_used <= buffers_required);
	}

      /* Prepare a copy order executed later for the data */
      ASSERT (*copy_len < VHOST_USER_COPY_ARRAY_N);
      vhost_copy_t *cpy = &cpu->copy[*copy_len];
      (*copy_len)++;
      desc_data_l = desc_table[*desc_idx].len - *desc_data_offset;
      cpy->len = 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_idx].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;
    }
  *desc_idx = (*desc_idx + 1) & mask;;
  *desc_data_offset = 0;
}

static_always_inline u32
vhost_user_if_input_packed (vlib_main_t *vm, vhost_user_main_t *vum,
			    vhost_user_intf_t *vui, u16 qid,
			    vlib_node_runtime_t *node, u8 enable_csum)
{
  vhost_user_vring_t *txvq = &vui->vrings[VHOST_VRING_IDX_TX (qid)];
  vnet_feature_main_t *fm = &feature_main;
  u8 feature_arc_idx = fm->device_input_feature_arc_index;
  u16 n_rx_packets = 0;
  u32 n_rx_bytes = 0;
  u16 n_left = 0;
  u32 buffers_required = 0;
  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 buffer_data_size = vlib_buffer_get_default_data_size (vm);
  u32 map_hint = 0;
  vhost_cpu_t *cpu = &vum->cpus[vm->thread_index];
  u16 copy_len = 0;
  u32 current_config_index = ~0;
  u16 mask = txvq->qsz_mask;
  u16 desc_current, desc_head, last_used_idx;
  vnet_virtio_vring_packed_desc_t *desc_table = 0;
  u32 n_descs_processed = 0;
  u32 rv;
  vlib_buffer_t **b;
  u32 *next;
  u32 buffers_used = 0;
  u16 current, n_descs_to_process;

  /* The descriptor table is not ready yet */
  if (PREDICT_FALSE (txvq->packed_desc == 0))
    goto done;

  /* do we have pending interrupts ? */
  vhost_user_vring_t *rxvq = &vui->vrings[VHOST_VRING_IDX_RX (qid)];
  vhost_user_input_do_interrupt (vm, vui, txvq, 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 (txvq->mode == VNET_HW_IF_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_event->flags = 0;
      else
	/* Tell driver we don't want notification */
	txvq->used_event->flags = VRING_EVENT_F_DISABLE;
    }

  last_used_idx = txvq->last_used_idx & mask;
  desc_head = desc_current = last_used_idx;

  if (vhost_user_packed_desc_available (txvq, desc_current) == 0)
    goto done;

  if (PREDICT_FALSE (!vui->admin_up || !vui->is_ready || !(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."
       */
      rv = vhost_user_rx_discard_packet_packed (vm, vui, txvq,
						VHOST_USER_DOWN_DISCARD_COUNT);
      vlib_error_count (vm, vhost_user_input_node.index,
			VHOST_USER_INPUT_FUNC_ERROR_NOT_READY, rv);
      goto done;
    }

  vhost_user_input_setup_frame (vm, node, vui, &current_config_index,
				&next_index, &to_next, &n_left_to_next);

  /*
   * Compute n_left and total buffers needed
   */
  desc_table = txvq->packed_desc;
  current = desc_current;
  while (vhost_user_packed_desc_available (txvq, current) &&
	 (n_left < VLIB_FRAME_SIZE))
    {
      if (desc_table[current].flags & VRING_DESC_F_INDIRECT)
	{
	  buffers_required +=
	    vhost_user_compute_indirect_desc_len (vui, txvq, buffer_data_size,
						  current, &map_hint);
	  n_left++;
	  current = (current + 1) & mask;
	  vhost_user_advance_last_avail_idx (txvq);
	}
      else
	{
	  buffers_required +=
	    vhost_user_compute_chained_desc_len (vui, txvq, buffer_data_size,
						 &current, &n_left);
	}
    }

  /* Something is broken if we need more than 10000 buffers */
  if (PREDICT_FALSE ((buffers_required == 0) || (buffers_required > 10000)))
    {
      rv = vhost_user_rx_discard_packet_packed (vm, vui, txvq, n_left);
      vlib_error_count (vm, vhost_user_input_node.index,
			VHOST_USER_INPUT_FUNC_ERROR_NO_BUFFER, rv);
      goto done;
    }

  vec_validate (cpu->to_next_list, buffers_required);
  rv = vlib_buffer_alloc (vm, cpu->to_next_list, buffers_required);
  if (PREDICT_FALSE (rv != buffers_required))
    {
      vlib_buffer_free (vm, cpu->to_next_list, rv);
      rv = vhost_user_rx_discard_packet_packed (vm, vui, txvq, n_left);
      vlib_error_count (vm, vhost_user_input_node.index,
			VHOST_USER_INPUT_FUNC_ERROR_NO_BUFFER, rv);
      goto done;
    }

  next = cpu->to_next_list;
  vec_validate (cpu->rx_buffers_pdesc, buffers_required);
  vlib_get_buffers (vm, next, cpu->rx_buffers_pdesc, buffers_required);
  b = cpu->rx_buffers_pdesc;
  n_descs_processed = n_left;

  while (n_left)
    {
      vlib_buffer_t *b_head, *b_current;
      u32 bi_current;
      u32 desc_data_offset;
      u16 desc_idx = desc_current;
      u32 n_descs;

      desc_table = txvq->packed_desc;
      to_next[0] = bi_current = next[0];
      b_head = b_current = b[0];
      b++;
      buffers_used++;
      ASSERT (buffers_used <= buffers_required);
      to_next++;
      next++;
      n_left_to_next--;

      /* The buffer should already be initialized */
      b_head->total_length_not_including_first_buffer = 0;
      b_head->flags |= VLIB_BUFFER_TOTAL_LENGTH_VALID;
      desc_data_offset = vui->virtio_net_hdr_sz;
      n_descs_to_process = 1;

      if (desc_table[desc_idx].flags & VRING_DESC_F_INDIRECT)
	{
	  n_descs = desc_table[desc_idx].len >> 4;
	  desc_table = map_guest_mem (vui, desc_table[desc_idx].addr,
				      &map_hint);
	  desc_idx = 0;
	  if (PREDICT_FALSE (desc_table == 0) ||
	      (enable_csum &&
	       (PREDICT_FALSE
		(vhost_user_do_offload
		 (vui, desc_table, desc_idx, mask, b_head,
		  &map_hint) != VHOST_USER_INPUT_FUNC_ERROR_NO_ERROR))))
	    {
	      vlib_error_count (vm, node->node_index,
				VHOST_USER_INPUT_FUNC_ERROR_MMAP_FAIL, 1);
	      to_next--;
	      next--;
	      n_left_to_next++;
	      buffers_used--;
	      b--;
	      goto out;
	    }
	  while (n_descs)
	    {
	      vhost_user_assemble_packet (desc_table, &desc_idx, b_head,
					  &b_current, &next, &b, &bi_current,
					  cpu, &copy_len, &buffers_used,
					  buffers_required, &desc_data_offset,
					  buffer_data_size, mask);
	      n_descs--;
	    }
	}
      else
	{
	  if (enable_csum)
	    {
	      rv = vhost_user_do_offload (vui, desc_table, desc_idx, mask,
					  b_head, &map_hint);
	      if (PREDICT_FALSE (rv != VHOST_USER_INPUT_FUNC_ERROR_NO_ERROR))
		{
		  vlib_error_count (vm, node->node_index, rv, 1);
		  to_next--;
		  next--;
		  n_left_to_next++;
		  buffers_used--;
		  b--;
		  goto out;
		}
	    }
	  /*
	   * For chained descriptor, we process all chains in a single while
	   * loop. So count how many descriptors in the chain.
	   */
	  n_descs_to_process = 1;
	  while (desc_table[desc_idx].flags & VRING_DESC_F_NEXT)
	    {
	      vhost_user_assemble_packet (desc_table, &desc_idx, b_head,
					  &b_current, &next, &b, &bi_current,
					  cpu, &copy_len, &buffers_used,
					  buffers_required, &desc_data_offset,
					  buffer_data_size, mask);
	      n_descs_to_process++;
	    }
	  vhost_user_assemble_packet (desc_table, &desc_idx, b_head,
				      &b_current, &next, &b, &bi_current,
				      cpu, &copy_len, &buffers_used,
				      buffers_required, &desc_data_offset,
				      buffer_data_size, mask);
	}

      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;

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

      if (current_config_index != ~0)
	{
	  b_head->current_config_index = current_config_index;
	  vnet_buffer (b_head)->feature_arc_index = feature_arc_idx;
	}

    out:
      ASSERT (n_left >= n_descs_to_process);
      n_left -= n_descs_to_process;

      /* advance to next descrptor */
      desc_current = (desc_current + n_descs_to_process) & mask;

      /*
       * 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))
	{
	  rv = vhost_user_input_copy_packed (vui, cpu->copy, copy_len,
					     &map_hint);
	  if (PREDICT_FALSE (rv != VHOST_USER_INPUT_FUNC_ERROR_NO_ERROR))
	    vlib_error_count (vm, node->node_index, rv, 1);
	  copy_len = 0;
	}
    }
  vlib_put_next_frame (vm, node, next_index, n_left_to_next);

  /* Do the memory copies */
  rv = vhost_user_input_copy_packed (vui, cpu->copy, copy_len, &map_hint);
  if (PREDICT_FALSE (rv != VHOST_USER_INPUT_FUNC_ERROR_NO_ERROR))
    vlib_error_count (vm, node->node_index, rv, 1);

  /* Must do the tracing before giving buffers back to driver */
  if (PREDICT_FALSE (n_trace))
    {
      u32 left = n_rx_packets;

      b = cpu->rx_buffers_pdesc;
      while (n_trace && left)
	{
	  if (PREDICT_TRUE
	      (vlib_trace_buffer
	       (vm, node, next_index, b[0], /* follow_chain */ 0)))
	    {
	      vhost_trace_t *t0;
	      t0 = vlib_add_trace (vm, node, b[0], sizeof (t0[0]));
	      vhost_user_rx_trace_packed (t0, vui, qid, txvq, last_used_idx);
	      last_used_idx = (last_used_idx + 1) & mask;
	      n_trace--;
	      vlib_set_trace_count (vm, node, n_trace);
	    }
	  left--;
	  b++;
	}
    }

  /*
   * Give buffers back to driver.
   */
  vhost_user_mark_desc_consumed (vui, txvq, desc_head, n_descs_processed);

  /* interrupt (call) handling */
  if ((txvq->callfd_idx != ~0) &&
      (txvq->avail_event->flags != VRING_EVENT_F_DISABLE))
    {
      txvq->n_since_last_int += n_rx_packets;
      if (txvq->n_since_last_int > vum->coalesce_frames)
	vhost_user_send_call (vm, vui, txvq);
    }

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

  vnet_device_increment_rx_packets (vm->thread_index, n_rx_packets);

  if (PREDICT_FALSE (buffers_used < buffers_required))
    vlib_buffer_free (vm, next, buffers_required - buffers_used);

done:
  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_hw_if_rxq_poll_vector_t *pv = vnet_hw_if_get_rxq_poll_vector (vm, node);
  vnet_hw_if_rxq_poll_vector_t *pve;

  vec_foreach (pve, pv)
    {
      vui = pool_elt_at_index (vum->vhost_user_interfaces, pve->dev_instance);
      if (vhost_user_is_packed_ring_supported (vui))
	{
	  if (vui->features & VIRTIO_FEATURE (VIRTIO_NET_F_CSUM))
	    n_rx_packets += vhost_user_if_input_packed (
	      vm, vum, vui, pve->queue_id, node, 1);
	  else
	    n_rx_packets += vhost_user_if_input_packed (
	      vm, vum, vui, pve->queue_id, node, 0);
	}
      else
	{
	  if (vui->features & VIRTIO_FEATURE (VIRTIO_NET_F_CSUM))
	    n_rx_packets +=
	      vhost_user_if_input (vm, vum, vui, pve->queue_id, node, 1);
	  else
	    n_rx_packets +=
	      vhost_user_if_input (vm, vum, vui, pve->queue_id, node, 0);
	}
    }

  return n_rx_packets;
}

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

  /* 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* */

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