dpdk: be a plugin

Change-Id: I238258cdeb77035adc5e88903d824593d0a1da90
Signed-off-by: Damjan Marion <damarion@cisco.com>

1 files changed, 674 insertions, 0 deletions

diff --git a/src/plugins/dpdk/device/node.c b/src/plugins/dpdk/device/node.c
new file mode 100644
index 00000000000..8824d78944e
--- /dev/null
+++ b/src/plugins/dpdk/device/node.c
@@ -0,0 +1,674 @@
+/*
+ * Copyright (c) 2015 Cisco and/or its affiliates.
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at:
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+#include <vnet/vnet.h>
+#include <vppinfra/vec.h>
+#include <vppinfra/error.h>
+#include <vppinfra/format.h>
+#include <vppinfra/xxhash.h>
+
+#include <vnet/ethernet/ethernet.h>
+#include <dpdk/device/dpdk.h>
+#include <vnet/classify/vnet_classify.h>
+#include <vnet/mpls/packet.h>
+#include <vnet/handoff.h>
+#include <vnet/devices/devices.h>
+#include <vnet/feature/feature.h>
+
+#include <dpdk/device/dpdk_priv.h>
+
+static char *dpdk_error_strings[] = {
+#define _(n,s) s,
+  foreach_dpdk_error
+#undef _
+};
+
+always_inline int
+vlib_buffer_is_ip4 (vlib_buffer_t * b)
+{
+  ethernet_header_t *h = (ethernet_header_t *) b->data;
+  return (h->type == clib_host_to_net_u16 (ETHERNET_TYPE_IP4));
+}
+
+always_inline int
+vlib_buffer_is_ip6 (vlib_buffer_t * b)
+{
+  ethernet_header_t *h = (ethernet_header_t *) b->data;
+  return (h->type == clib_host_to_net_u16 (ETHERNET_TYPE_IP6));
+}
+
+always_inline int
+vlib_buffer_is_mpls (vlib_buffer_t * b)
+{
+  ethernet_header_t *h = (ethernet_header_t *) b->data;
+  return (h->type == clib_host_to_net_u16 (ETHERNET_TYPE_MPLS_UNICAST));
+}
+
+always_inline u32
+dpdk_rx_next_from_etype (struct rte_mbuf * mb, vlib_buffer_t * b0)
+{
+  if (PREDICT_TRUE (vlib_buffer_is_ip4 (b0)))
+    if (PREDICT_TRUE ((mb->ol_flags & PKT_RX_IP_CKSUM_GOOD) != 0))
+      return VNET_DEVICE_INPUT_NEXT_IP4_NCS_INPUT;
+    else
+      return VNET_DEVICE_INPUT_NEXT_IP4_INPUT;
+  else if (PREDICT_TRUE (vlib_buffer_is_ip6 (b0)))
+    return VNET_DEVICE_INPUT_NEXT_IP6_INPUT;
+  else if (PREDICT_TRUE (vlib_buffer_is_mpls (b0)))
+    return VNET_DEVICE_INPUT_NEXT_MPLS_INPUT;
+  else
+    return VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
+}
+
+always_inline int
+dpdk_mbuf_is_vlan (struct rte_mbuf *mb)
+{
+  return (mb->packet_type & RTE_PTYPE_L2_ETHER_VLAN) ==
+    RTE_PTYPE_L2_ETHER_VLAN;
+}
+
+always_inline int
+dpdk_mbuf_is_ip4 (struct rte_mbuf *mb)
+{
+  return RTE_ETH_IS_IPV4_HDR (mb->packet_type) != 0;
+}
+
+always_inline int
+dpdk_mbuf_is_ip6 (struct rte_mbuf *mb)
+{
+  return RTE_ETH_IS_IPV6_HDR (mb->packet_type) != 0;
+}
+
+always_inline u32
+dpdk_rx_next_from_mb (struct rte_mbuf * mb, vlib_buffer_t * b0)
+{
+  if (PREDICT_FALSE (dpdk_mbuf_is_vlan (mb)))
+    return VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
+  else if (PREDICT_TRUE (dpdk_mbuf_is_ip4 (mb)))
+    return VNET_DEVICE_INPUT_NEXT_IP4_NCS_INPUT;
+  else if (PREDICT_TRUE (dpdk_mbuf_is_ip6 (mb)))
+    return VNET_DEVICE_INPUT_NEXT_IP6_INPUT;
+  else if (PREDICT_TRUE (vlib_buffer_is_mpls (b0)))
+    return VNET_DEVICE_INPUT_NEXT_MPLS_INPUT;
+  else
+    return dpdk_rx_next_from_etype (mb, b0);
+}
+
+always_inline void
+dpdk_rx_error_from_mb (struct rte_mbuf *mb, u32 * next, u8 * error)
+{
+  if (mb->ol_flags & PKT_RX_IP_CKSUM_BAD)
+    {
+      *error = DPDK_ERROR_IP_CHECKSUM_ERROR;
+      *next = VNET_DEVICE_INPUT_NEXT_DROP;
+    }
+  else
+    *error = DPDK_ERROR_NONE;
+}
+
+void
+dpdk_rx_trace (dpdk_main_t * dm,
+	       vlib_node_runtime_t * node,
+	       dpdk_device_t * xd,
+	       u16 queue_id, u32 * buffers, uword n_buffers)
+{
+  vlib_main_t *vm = vlib_get_main ();
+  u32 *b, n_left;
+  u32 next0;
+
+  n_left = n_buffers;
+  b = buffers;
+
+  while (n_left >= 1)
+    {
+      u32 bi0;
+      vlib_buffer_t *b0;
+      dpdk_rx_dma_trace_t *t0;
+      struct rte_mbuf *mb;
+      u8 error0;
+
+      bi0 = b[0];
+      n_left -= 1;
+
+      b0 = vlib_get_buffer (vm, bi0);
+      mb = rte_mbuf_from_vlib_buffer (b0);
+
+      if (PREDICT_FALSE (xd->per_interface_next_index != ~0))
+	next0 = xd->per_interface_next_index;
+      else if (PREDICT_TRUE
+	       ((xd->flags & DPDK_DEVICE_FLAG_PMD_SUPPORTS_PTYPE) != 0))
+	next0 = dpdk_rx_next_from_mb (mb, b0);
+      else
+	next0 = dpdk_rx_next_from_etype (mb, b0);
+
+      dpdk_rx_error_from_mb (mb, &next0, &error0);
+
+      vlib_trace_buffer (vm, node, next0, b0, /* follow_chain */ 0);
+      t0 = vlib_add_trace (vm, node, b0, sizeof (t0[0]));
+      t0->queue_index = queue_id;
+      t0->device_index = xd->device_index;
+      t0->buffer_index = bi0;
+
+      clib_memcpy (&t0->mb, mb, sizeof (t0->mb));
+      clib_memcpy (&t0->buffer, b0, sizeof (b0[0]) - sizeof (b0->pre_data));
+      clib_memcpy (t0->buffer.pre_data, b0->data,
+		   sizeof (t0->buffer.pre_data));
+      clib_memcpy (&t0->data, mb->buf_addr + mb->data_off, sizeof (t0->data));
+
+      b += 1;
+    }
+}
+
+static inline u32
+dpdk_rx_burst (dpdk_main_t * dm, dpdk_device_t * xd, u16 queue_id)
+{
+  u32 n_buffers;
+  u32 n_left;
+  u32 n_this_chunk;
+
+  n_left = VLIB_FRAME_SIZE;
+  n_buffers = 0;
+
+  if (PREDICT_TRUE (xd->flags & DPDK_DEVICE_FLAG_PMD))
+    {
+      while (n_left)
+	{
+	  n_this_chunk = rte_eth_rx_burst (xd->device_index, queue_id,
+					   xd->rx_vectors[queue_id] +
+					   n_buffers, n_left);
+	  n_buffers += n_this_chunk;
+	  n_left -= n_this_chunk;
+
+	  /* Empirically, DPDK r1.8 produces vectors w/ 32 or fewer elts */
+	  if (n_this_chunk < 32)
+	    break;
+	}
+    }
+  else
+    {
+      ASSERT (0);
+    }
+
+  return n_buffers;
+}
+
+
+static_always_inline void
+dpdk_process_subseq_segs (vlib_main_t * vm, vlib_buffer_t * b,
+			  struct rte_mbuf *mb, vlib_buffer_free_list_t * fl)
+{
+  u8 nb_seg = 1;
+  struct rte_mbuf *mb_seg = 0;
+  vlib_buffer_t *b_seg, *b_chain = 0;
+  mb_seg = mb->next;
+  b_chain = b;
+
+  while ((mb->nb_segs > 1) && (nb_seg < mb->nb_segs))
+    {
+      ASSERT (mb_seg != 0);
+
+      b_seg = vlib_buffer_from_rte_mbuf (mb_seg);
+      vlib_buffer_init_for_free_list (b_seg, fl);
+
+      ASSERT ((b_seg->flags & VLIB_BUFFER_NEXT_PRESENT) == 0);
+      ASSERT (b_seg->current_data == 0);
+
+      /*
+       * The driver (e.g. virtio) may not put the packet data at the start
+       * of the segment, so don't assume b_seg->current_data == 0 is correct.
+       */
+      b_seg->current_data =
+	(mb_seg->buf_addr + mb_seg->data_off) - (void *) b_seg->data;
+
+      b_seg->current_length = mb_seg->data_len;
+      b->total_length_not_including_first_buffer += mb_seg->data_len;
+
+      b_chain->flags |= VLIB_BUFFER_NEXT_PRESENT;
+      b_chain->next_buffer = vlib_get_buffer_index (vm, b_seg);
+
+      b_chain = b_seg;
+      mb_seg = mb_seg->next;
+      nb_seg++;
+    }
+}
+
+static_always_inline void
+dpdk_prefetch_buffer (struct rte_mbuf *mb)
+{
+  vlib_buffer_t *b = vlib_buffer_from_rte_mbuf (mb);
+  CLIB_PREFETCH (mb, CLIB_CACHE_LINE_BYTES, LOAD);
+  CLIB_PREFETCH (b, CLIB_CACHE_LINE_BYTES, STORE);
+}
+
+/*
+ * This function is used when there are no worker threads.
+ * The main thread performs IO and forwards the packets.
+ */
+static_always_inline u32
+dpdk_device_input (dpdk_main_t * dm, dpdk_device_t * xd,
+		   vlib_node_runtime_t * node, u32 cpu_index, u16 queue_id)
+{
+  u32 n_buffers;
+  u32 next_index = VNET_DEVICE_INPUT_NEXT_ETHERNET_INPUT;
+  u32 n_left_to_next, *to_next;
+  u32 mb_index;
+  vlib_main_t *vm = vlib_get_main ();
+  uword n_rx_bytes = 0;
+  u32 n_trace, trace_cnt __attribute__ ((unused));
+  vlib_buffer_free_list_t *fl;
+  u32 buffer_flags_template;
+
+  if ((xd->flags & DPDK_DEVICE_FLAG_ADMIN_UP) == 0)
+    return 0;
+
+  n_buffers = dpdk_rx_burst (dm, xd, queue_id);
+
+  if (n_buffers == 0)
+    {
+      return 0;
+    }
+
+  buffer_flags_template = dm->buffer_flags_template;
+
+  vec_reset_length (xd->d_trace_buffers[cpu_index]);
+  trace_cnt = n_trace = vlib_get_trace_count (vm, node);
+
+  if (n_trace > 0)
+    {
+      u32 n = clib_min (n_trace, n_buffers);
+      mb_index = 0;
+
+      while (n--)
+	{
+	  struct rte_mbuf *mb = xd->rx_vectors[queue_id][mb_index++];
+	  vlib_buffer_t *b = vlib_buffer_from_rte_mbuf (mb);
+	  vec_add1 (xd->d_trace_buffers[cpu_index],
+		    vlib_get_buffer_index (vm, b));
+	}
+    }
+
+  fl = vlib_buffer_get_free_list (vm, VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
+
+  mb_index = 0;
+
+  while (n_buffers > 0)
+    {
+      vlib_buffer_t *b0, *b1, *b2, *b3;
+      u32 bi0, next0, l3_offset0;
+      u32 bi1, next1, l3_offset1;
+      u32 bi2, next2, l3_offset2;
+      u32 bi3, next3, l3_offset3;
+      u8 error0, error1, error2, error3;
+      u64 or_ol_flags;
+
+      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+
+      while (n_buffers > 8 && n_left_to_next > 4)
+	{
+	  struct rte_mbuf *mb0 = xd->rx_vectors[queue_id][mb_index];
+	  struct rte_mbuf *mb1 = xd->rx_vectors[queue_id][mb_index + 1];
+	  struct rte_mbuf *mb2 = xd->rx_vectors[queue_id][mb_index + 2];
+	  struct rte_mbuf *mb3 = xd->rx_vectors[queue_id][mb_index + 3];
+
+	  dpdk_prefetch_buffer (xd->rx_vectors[queue_id][mb_index + 4]);
+	  dpdk_prefetch_buffer (xd->rx_vectors[queue_id][mb_index + 5]);
+	  dpdk_prefetch_buffer (xd->rx_vectors[queue_id][mb_index + 6]);
+	  dpdk_prefetch_buffer (xd->rx_vectors[queue_id][mb_index + 7]);
+
+	  if (xd->flags & DPDK_DEVICE_FLAG_MAYBE_MULTISEG)
+	    {
+	      if (PREDICT_FALSE (mb0->nb_segs > 1))
+		dpdk_prefetch_buffer (mb0->next);
+	      if (PREDICT_FALSE (mb1->nb_segs > 1))
+		dpdk_prefetch_buffer (mb1->next);
+	      if (PREDICT_FALSE (mb2->nb_segs > 1))
+		dpdk_prefetch_buffer (mb2->next);
+	      if (PREDICT_FALSE (mb3->nb_segs > 1))
+		dpdk_prefetch_buffer (mb3->next);
+	    }
+
+	  ASSERT (mb0);
+	  ASSERT (mb1);
+	  ASSERT (mb2);
+	  ASSERT (mb3);
+
+	  or_ol_flags = (mb0->ol_flags | mb1->ol_flags |
+			 mb2->ol_flags | mb3->ol_flags);
+	  b0 = vlib_buffer_from_rte_mbuf (mb0);
+	  b1 = vlib_buffer_from_rte_mbuf (mb1);
+	  b2 = vlib_buffer_from_rte_mbuf (mb2);
+	  b3 = vlib_buffer_from_rte_mbuf (mb3);
+
+	  vlib_buffer_init_for_free_list (b0, fl);
+	  vlib_buffer_init_for_free_list (b1, fl);
+	  vlib_buffer_init_for_free_list (b2, fl);
+	  vlib_buffer_init_for_free_list (b3, fl);
+
+	  bi0 = vlib_get_buffer_index (vm, b0);
+	  bi1 = vlib_get_buffer_index (vm, b1);
+	  bi2 = vlib_get_buffer_index (vm, b2);
+	  bi3 = vlib_get_buffer_index (vm, b3);
+
+	  to_next[0] = bi0;
+	  to_next[1] = bi1;
+	  to_next[2] = bi2;
+	  to_next[3] = bi3;
+	  to_next += 4;
+	  n_left_to_next -= 4;
+
+	  if (PREDICT_FALSE (xd->per_interface_next_index != ~0))
+	    {
+	      next0 = next1 = next2 = next3 = xd->per_interface_next_index;
+	    }
+	  else if (PREDICT_TRUE
+		   ((xd->flags & DPDK_DEVICE_FLAG_PMD_SUPPORTS_PTYPE) != 0))
+	    {
+	      next0 = dpdk_rx_next_from_mb (mb0, b0);
+	      next1 = dpdk_rx_next_from_mb (mb1, b1);
+	      next2 = dpdk_rx_next_from_mb (mb2, b2);
+	      next3 = dpdk_rx_next_from_mb (mb3, b3);
+	    }
+	  else
+	    {
+	      next0 = dpdk_rx_next_from_etype (mb0, b0);
+	      next1 = dpdk_rx_next_from_etype (mb1, b1);
+	      next2 = dpdk_rx_next_from_etype (mb2, b2);
+	      next3 = dpdk_rx_next_from_etype (mb3, b3);
+	    }
+
+	  if (PREDICT_FALSE (or_ol_flags & PKT_RX_IP_CKSUM_BAD))
+	    {
+	      dpdk_rx_error_from_mb (mb0, &next0, &error0);
+	      dpdk_rx_error_from_mb (mb1, &next1, &error1);
+	      dpdk_rx_error_from_mb (mb2, &next2, &error2);
+	      dpdk_rx_error_from_mb (mb3, &next3, &error3);
+	      b0->error = node->errors[error0];
+	      b1->error = node->errors[error1];
+	      b2->error = node->errors[error2];
+	      b3->error = node->errors[error3];
+	    }
+	  else
+	    {
+	      b0->error = b1->error = node->errors[DPDK_ERROR_NONE];
+	      b2->error = b3->error = node->errors[DPDK_ERROR_NONE];
+	    }
+
+	  l3_offset0 = device_input_next_node_advance[next0];
+	  l3_offset1 = device_input_next_node_advance[next1];
+	  l3_offset2 = device_input_next_node_advance[next2];
+	  l3_offset3 = device_input_next_node_advance[next3];
+
+	  b0->current_data = l3_offset0 + mb0->data_off;
+	  b1->current_data = l3_offset1 + mb1->data_off;
+	  b2->current_data = l3_offset2 + mb2->data_off;
+	  b3->current_data = l3_offset3 + mb3->data_off;
+
+	  b0->current_data -= RTE_PKTMBUF_HEADROOM;
+	  b1->current_data -= RTE_PKTMBUF_HEADROOM;
+	  b2->current_data -= RTE_PKTMBUF_HEADROOM;
+	  b3->current_data -= RTE_PKTMBUF_HEADROOM;
+
+	  b0->current_length = mb0->data_len - l3_offset0;
+	  b1->current_length = mb1->data_len - l3_offset1;
+	  b2->current_length = mb2->data_len - l3_offset2;
+	  b3->current_length = mb3->data_len - l3_offset3;
+
+	  b0->flags = buffer_flags_template;
+	  b1->flags = buffer_flags_template;
+	  b2->flags = buffer_flags_template;
+	  b3->flags = buffer_flags_template;
+
+	  vnet_buffer (b0)->sw_if_index[VLIB_RX] = xd->vlib_sw_if_index;
+	  vnet_buffer (b1)->sw_if_index[VLIB_RX] = xd->vlib_sw_if_index;
+	  vnet_buffer (b2)->sw_if_index[VLIB_RX] = xd->vlib_sw_if_index;
+	  vnet_buffer (b3)->sw_if_index[VLIB_RX] = xd->vlib_sw_if_index;
+
+	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+	  vnet_buffer (b1)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+	  vnet_buffer (b2)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+	  vnet_buffer (b3)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+
+	  n_rx_bytes += mb0->pkt_len;
+	  n_rx_bytes += mb1->pkt_len;
+	  n_rx_bytes += mb2->pkt_len;
+	  n_rx_bytes += mb3->pkt_len;
+
+	  /* Process subsequent segments of multi-segment packets */
+	  if (xd->flags & DPDK_DEVICE_FLAG_MAYBE_MULTISEG)
+	    {
+	      dpdk_process_subseq_segs (vm, b0, mb0, fl);
+	      dpdk_process_subseq_segs (vm, b1, mb1, fl);
+	      dpdk_process_subseq_segs (vm, b2, mb2, fl);
+	      dpdk_process_subseq_segs (vm, b3, mb3, fl);
+	    }
+
+	  /*
+	   * Turn this on if you run into
+	   * "bad monkey" contexts, and you want to know exactly
+	   * which nodes they've visited... See main.c...
+	   */
+	  VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b0);
+	  VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b1);
+	  VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b2);
+	  VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b3);
+
+	  /* Do we have any driver RX features configured on the interface? */
+	  vnet_feature_start_device_input_x4 (xd->vlib_sw_if_index,
+					      &next0, &next1, &next2, &next3,
+					      b0, b1, b2, b3,
+					      l3_offset0, l3_offset1,
+					      l3_offset2, l3_offset3);
+
+	  vlib_validate_buffer_enqueue_x4 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, bi1, bi2, bi3,
+					   next0, next1, next2, next3);
+	  n_buffers -= 4;
+	  mb_index += 4;
+	}
+      while (n_buffers > 0 && n_left_to_next > 0)
+	{
+	  struct rte_mbuf *mb0 = xd->rx_vectors[queue_id][mb_index];
+
+	  ASSERT (mb0);
+
+	  b0 = vlib_buffer_from_rte_mbuf (mb0);
+
+	  /* Prefetch one next segment if it exists. */
+	  if (PREDICT_FALSE (mb0->nb_segs > 1))
+	    dpdk_prefetch_buffer (mb0->next);
+
+	  vlib_buffer_init_for_free_list (b0, fl);
+
+	  bi0 = vlib_get_buffer_index (vm, b0);
+
+	  to_next[0] = bi0;
+	  to_next++;
+	  n_left_to_next--;
+
+	  if (PREDICT_FALSE (xd->per_interface_next_index != ~0))
+	    next0 = xd->per_interface_next_index;
+	  else if (PREDICT_TRUE
+		   ((xd->flags & DPDK_DEVICE_FLAG_PMD_SUPPORTS_PTYPE) != 0))
+	    next0 = dpdk_rx_next_from_mb (mb0, b0);
+	  else
+	    next0 = dpdk_rx_next_from_etype (mb0, b0);
+
+	  dpdk_rx_error_from_mb (mb0, &next0, &error0);
+	  b0->error = node->errors[error0];
+
+	  l3_offset0 = device_input_next_node_advance[next0];
+
+	  b0->current_data = l3_offset0;
+	  b0->current_data += mb0->data_off - RTE_PKTMBUF_HEADROOM;
+	  b0->current_length = mb0->data_len - l3_offset0;
+
+	  b0->flags = buffer_flags_template;
+
+	  vnet_buffer (b0)->sw_if_index[VLIB_RX] = xd->vlib_sw_if_index;
+	  vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
+	  n_rx_bytes += mb0->pkt_len;
+
+	  /* Process subsequent segments of multi-segment packets */
+	  dpdk_process_subseq_segs (vm, b0, mb0, fl);
+
+	  /*
+	   * Turn this on if you run into
+	   * "bad monkey" contexts, and you want to know exactly
+	   * which nodes they've visited... See main.c...
+	   */
+	  VLIB_BUFFER_TRACE_TRAJECTORY_INIT (b0);
+
+	  /* Do we have any driver RX features configured on the interface? */
+	  vnet_feature_start_device_input_x1 (xd->vlib_sw_if_index, &next0,
+					      b0, l3_offset0);
+
+	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
+					   to_next, n_left_to_next,
+					   bi0, next0);
+	  n_buffers--;
+	  mb_index++;
+	}
+      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+    }
+
+  if (PREDICT_FALSE (vec_len (xd->d_trace_buffers[cpu_index]) > 0))
+    {
+      dpdk_rx_trace (dm, node, xd, queue_id, xd->d_trace_buffers[cpu_index],
+		     vec_len (xd->d_trace_buffers[cpu_index]));
+      vlib_set_trace_count (vm, node, n_trace -
+			    vec_len (xd->d_trace_buffers[cpu_index]));
+    }
+
+  vlib_increment_combined_counter
+    (vnet_get_main ()->interface_main.combined_sw_if_counters
+     + VNET_INTERFACE_COUNTER_RX,
+     cpu_index, xd->vlib_sw_if_index, mb_index, n_rx_bytes);
+
+  vnet_device_increment_rx_packets (cpu_index, mb_index);
+
+  return mb_index;
+}
+
+static inline void
+poll_rate_limit (dpdk_main_t * dm)
+{
+  /* Limit the poll rate by sleeping for N msec between polls */
+  if (PREDICT_FALSE (dm->poll_sleep != 0))
+    {
+      struct timespec ts, tsrem;
+
+      ts.tv_sec = 0;
+      ts.tv_nsec = 1000 * 1000 * dm->poll_sleep;	/* 1ms */
+
+      while (nanosleep (&ts, &tsrem) < 0)
+	{
+	  ts = tsrem;
+	}
+    }
+}
+
+/** \brief Main DPDK input node
+    @node dpdk-input
+
+    This is the main DPDK input node: across each assigned interface,
+    call rte_eth_rx_burst(...) or similar to obtain a vector of
+    packets to process. Handle early packet discard. Derive @c
+    vlib_buffer_t metadata from <code>struct rte_mbuf</code> metadata,
+    Depending on the resulting metadata: adjust <code>b->current_data,
+    b->current_length </code> and dispatch directly to
+    ip4-input-no-checksum, or ip6-input. Trace the packet if required.
+
+    @param vm   vlib_main_t corresponding to the current thread
+    @param node vlib_node_runtime_t
+    @param f    vlib_frame_t input-node, not used.
+
+    @par Graph mechanics: buffer metadata, next index usage
+
+    @em Uses:
+    - <code>struct rte_mbuf mb->ol_flags</code>
+        - PKT_RX_IP_CKSUM_BAD
+    - <code> RTE_ETH_IS_xxx_HDR(mb->packet_type) </code>
+        - packet classification result
+
+    @em Sets:
+    - <code>b->error</code> if the packet is to be dropped immediately
+    - <code>b->current_data, b->current_length</code>
+        - adjusted as needed to skip the L2 header in  direct-dispatch cases
+    - <code>vnet_buffer(b)->sw_if_index[VLIB_RX]</code>
+        - rx interface sw_if_index
+    - <code>vnet_buffer(b)->sw_if_index[VLIB_TX] = ~0</code>
+        - required by ipX-lookup
+    - <code>b->flags</code>
+        - to indicate multi-segment pkts (VLIB_BUFFER_NEXT_PRESENT), etc.
+
+    <em>Next Nodes:</em>
+    - Static arcs to: error-drop, ethernet-input,
+      ip4-input-no-checksum, ip6-input, mpls-input
+    - per-interface redirection, controlled by
+      <code>xd->per_interface_next_index</code>
+*/
+
+static uword
+dpdk_input (vlib_main_t * vm, vlib_node_runtime_t * node, vlib_frame_t * f)
+{
+  dpdk_main_t *dm = &dpdk_main;
+  dpdk_device_t *xd;
+  uword n_rx_packets = 0;
+  dpdk_device_and_queue_t *dq;
+  u32 cpu_index = os_get_cpu_number ();
+
+  /*
+   * Poll all devices on this cpu for input/interrupts.
+   */
+  /* *INDENT-OFF* */
+  vec_foreach (dq, dm->devices_by_cpu[cpu_index])
+    {
+      xd = vec_elt_at_index(dm->devices, dq->device);
+      n_rx_packets += dpdk_device_input (dm, xd, node, cpu_index, dq->queue_id);
+    }
+  /* *INDENT-ON* */
+
+  poll_rate_limit (dm);
+
+  return n_rx_packets;
+}
+
+/* *INDENT-OFF* */
+VLIB_REGISTER_NODE (dpdk_input_node) = {
+  .function = dpdk_input,
+  .type = VLIB_NODE_TYPE_INPUT,
+  .name = "dpdk-input",
+  .sibling_of = "device-input",
+
+  /* Will be enabled if/when hardware is detected. */
+  .state = VLIB_NODE_STATE_DISABLED,
+
+  .format_buffer = format_ethernet_header_with_length,
+  .format_trace = format_dpdk_rx_dma_trace,
+
+  .n_errors = DPDK_N_ERROR,
+  .error_strings = dpdk_error_strings,
+};
+
+VLIB_NODE_FUNCTION_MULTIARCH (dpdk_input_node, dpdk_input);
+/* *INDENT-ON* */
+
+/*
+ * fd.io coding-style-patch-verification: ON
+ *
+ * Local Variables:
+ * eval: (c-set-style "gnu")
+ * End:
+ */