Retire io threads and main-thread-io mode

Change-Id: I64f5ec5e32f200834c63ec3b304f9f20cef332a7
Signed-off-by: Damjan Marion <damarion@cisco.com>

10 files changed, 19 insertions, 1001 deletions

diff --git a/vlib/vlib/threads.c b/vlib/vlib/threads.c
index 3b815be42e1..1808f36fe50 100644
--- a/vlib/vlib/threads.c
+++ b/vlib/vlib/threads.c
@@ -983,9 +983,7 @@ cpu_config (vlib_main_t * vm, unformat_input_t * input)
 
   while (unformat_check_input(input) != UNFORMAT_END_OF_INPUT)
     {
-      if (unformat (input, "main-thread-io"))
-        tm->main_thread_is_io_node = 1;
-      else if (unformat (input, "use-pthreads"))
+      if (unformat (input, "use-pthreads"))
         tm->use_pthreads = 1;
       else if (unformat (input, "thread-prefix %v", &tm->thread_prefix))
           ;
diff --git a/vlib/vlib/threads.h b/vlib/vlib/threads.h
index f13d3768e42..f81be798626 100644
--- a/vlib/vlib/threads.h
+++ b/vlib/vlib/threads.h
@@ -264,9 +264,6 @@ typedef struct {
 
   vlib_worker_thread_t * worker_threads;
 
-  /* thread / cpu / io thread parameters */
-  u32 main_thread_is_io_node;
-
   /* 
    * Launch all threads as pthreads, 
    * not eal_rte_launch (strict affinity) threads 
diff --git a/vnet/vnet/devices/dpdk/device.c b/vnet/vnet/devices/dpdk/device.c
index bad149f03c6..f4d4fe779e1 100644
--- a/vnet/vnet/devices/dpdk/device.c
+++ b/vnet/vnet/devices/dpdk/device.c
@@ -1309,16 +1309,6 @@ u32 dpdk_num_mbufs (void)
 }
 
 /*
- * Return the io_thread_release
- */
-int dpdk_io_thread_release (void)
-{
-  dpdk_main_t * dm = &dpdk_main;
-
-  return dm->io_thread_release;
-}
-
-/*
  * Return the pmd type for a given hardware interface
  */
 dpdk_pmd_t dpdk_get_pmd_type (vnet_hw_interface_t *hi)
diff --git a/vnet/vnet/devices/dpdk/dpdk.h b/vnet/vnet/devices/dpdk/dpdk.h
index 1e7d36846cd..ded9d2db709 100644
--- a/vnet/vnet/devices/dpdk/dpdk.h
+++ b/vnet/vnet/devices/dpdk/dpdk.h
@@ -67,7 +67,6 @@
 
 extern vnet_device_class_t dpdk_device_class;
 extern vlib_node_registration_t dpdk_input_node;
-extern vlib_node_registration_t dpdk_io_input_node;
 extern vlib_node_registration_t handoff_dispatch_node;
 
 typedef enum {
@@ -391,7 +390,7 @@ typedef struct {
   u32 ethernet_input_node_index;
 
   /* dpdk i/o thread initialization barrier */
-  volatile u32 io_thread_release;
+  volatile u32 worker_thread_release;
 
   /* pcap tracing [only works if (CLIB_DEBUG > 0)] */
   int tx_pcap_enable;
@@ -417,7 +416,6 @@ typedef struct {
    */
   u8 admin_up_down_in_progress;
 
-  u8 have_io_threads;
   u8 use_rss;
 
   /* which cpus are running dpdk-input */
@@ -479,13 +477,6 @@ clib_error_t * dpdk_set_mac_address (vnet_hw_interface_t * hi, char * address);
 clib_error_t * dpdk_set_mc_filter (vnet_hw_interface_t * hi,
                                    struct ether_addr mc_addr_vec[], int naddr);
 
-typedef void (*dpdk_io_thread_callback_t) (vlib_main_t *vm);
-
-void dpdk_io_thread (vlib_worker_thread_t * w,
-                     u32 instances,
-                     u32 instance_id,
-                     char *worker_name,
-                     dpdk_io_thread_callback_t callback);
 void dpdk_thread_input (dpdk_main_t * dm, dpdk_device_t * xd);
 
 clib_error_t * dpdk_port_setup (dpdk_main_t * dm, dpdk_device_t * xd);
@@ -607,8 +598,6 @@ u32 dpdk_get_admin_up_down_in_progress (void);
 
 u32 dpdk_num_mbufs (void);
 
-int dpdk_io_thread_release (void);
-
 dpdk_pmd_t dpdk_get_pmd_type (vnet_hw_interface_t *hi);
 
 i8 dpdk_get_cpu_socket (vnet_hw_interface_t *hi);
diff --git a/vnet/vnet/devices/dpdk/init.c b/vnet/vnet/devices/dpdk/init.c
index 6b6f63a7ea8..398bd19e193 100644
--- a/vnet/vnet/devices/dpdk/init.c
+++ b/vnet/vnet/devices/dpdk/init.c
@@ -252,20 +252,9 @@ dpdk_lib_init (dpdk_main_t * dm)
   rt->function = dpdk_input_multiarch_select();
 
   /* find out which cpus will be used for input */
-  p = hash_get_mem (tm->thread_registrations_by_name, "io");
+  p = hash_get_mem (tm->thread_registrations_by_name, "workers");
   tr = p ? (vlib_thread_registration_t *) p[0] : 0;
 
-  if (!tr || tr->count == 0)
-    {
-      /* no io threads, workers doing input */
-      p = hash_get_mem (tm->thread_registrations_by_name, "workers");
-      tr = p ? (vlib_thread_registration_t *) p[0] : 0;
-    }
-  else
-    {
-      dm->have_io_threads = 1;
-    }
-
   if (tr && tr->count > 0)
     {
       dm->input_cpu_first_index = tr->first_index;
@@ -1521,10 +1510,7 @@ dpdk_process (vlib_main_t * vm,
         if (tm->n_vlib_mains == 1)
           vlib_node_set_state (vm, dpdk_input_node.index,
                                VLIB_NODE_STATE_POLLING);
-        else if (tm->main_thread_is_io_node)
-          vlib_node_set_state (vm, dpdk_io_input_node.index,
-                               VLIB_NODE_STATE_POLLING);
-        else if (!dm->have_io_threads)
+        else
           for (i=0; i < tm->n_vlib_mains; i++)
             if (vec_len(dm->devices_by_cpu[i]) > 0)
               vlib_node_set_state (vlib_mains[i], dpdk_input_node.index,
@@ -1536,7 +1522,7 @@ dpdk_process (vlib_main_t * vm,
 
   dpdk_vhost_user_process_init(&vu_state);
 
-  dm->io_thread_release = 1;
+  dm->worker_thread_release = 1;
 
   f64 now = vlib_time_now (vm);
   vec_foreach (xd, dm->devices)
diff --git a/vnet/vnet/devices/dpdk/node.c b/vnet/vnet/devices/dpdk/node.c
index 27670f37d98..0d453085cf1 100644
--- a/vnet/vnet/devices/dpdk/node.c
+++ b/vnet/vnet/devices/dpdk/node.c
@@ -687,7 +687,6 @@ CLIB_MULTIARCH_SELECT_FN(dpdk_input_efd);
 void dpdk_set_next_node (dpdk_rx_next_t next, char *name)
 {
   vlib_node_registration_t *r = &dpdk_input_node;
-  vlib_node_registration_t *r_io = &dpdk_io_input_node;
   vlib_node_registration_t *r_handoff = &handoff_dispatch_node;
 
   switch (next)
@@ -697,7 +696,6 @@ void dpdk_set_next_node (dpdk_rx_next_t next, char *name)
     case DPDK_RX_NEXT_MPLS_INPUT:
     case DPDK_RX_NEXT_ETHERNET_INPUT:
       r->next_nodes[next] = name;
-      r_io->next_nodes[next] = name;
       r_handoff->next_nodes[next] = name;
       break;
 
@@ -708,899 +706,6 @@ void dpdk_set_next_node (dpdk_rx_next_t next, char *name)
 }
 
 /*
- * This function is used when dedicated IO threads feed the worker threads.
- *
- * Devices are allocated to this thread based on instances and instance_id.
- * If instances==0 then the function automatically determines the number
- * of instances of this thread, and allocates devices between them. 
- * If instances != 0, then instance_id must be in the range 0..instances-1.
- * The function allocates devices among the specified number of instances,
- * with this thread having the given instance id. This option is used for 
- * splitting devices among differently named "io"-type threads.
- */
-void dpdk_io_thread (vlib_worker_thread_t * w,
-                     u32 instances,
-                     u32 instance_id,
-                     char *worker_name,
-                     dpdk_io_thread_callback_t callback)
-{
-  vlib_main_t * vm = vlib_get_main();
-  vlib_thread_main_t * tm = vlib_get_thread_main();
-  vlib_thread_registration_t * tr;
-  dpdk_main_t * dm = &dpdk_main;
-  char *io_name = w->registration->name;
-  dpdk_device_t * xd;
-  dpdk_device_t ** my_devices = 0;
-  vlib_frame_queue_elt_t ** handoff_queue_elt_by_worker_index = 0;
-  vlib_frame_queue_t ** congested_handoff_queue_by_worker_index = 0;
-  vlib_frame_queue_elt_t * hf = 0;
-  int i;
-  u32 n_left_to_next_worker = 0, * to_next_worker = 0;
-  u32 next_worker_index = 0;
-  u32 current_worker_index = ~0;
-  u32 cpu_index = os_get_cpu_number();
-  u32 num_workers = 0;
-  u32 num_devices = 0;
-  uword * p;
-  u16 queue_id = 0;
-  vlib_node_runtime_t * node_trace = 0;
-  u32 first_worker_index = 0;
-  u32 buffer_flags_template;
-  
-  /* Wait until the dpdk init sequence is complete */
-  while (dm->io_thread_release == 0)
-    vlib_worker_thread_barrier_check();
-
-  clib_time_init (&vm->clib_time);
-
-  p = hash_get_mem (tm->thread_registrations_by_name, worker_name);
-  ASSERT (p);
-  tr = (vlib_thread_registration_t *) p[0];
-  if (tr) 
-    {
-      num_workers = tr->count;
-      first_worker_index = tr->first_index;
-    }
-
-  /* Allocate devices to this thread */
-  if (instances == 0) 
-    {
-      /* auto-assign */
-      instance_id = w->instance_id;
-
-      p = hash_get_mem (tm->thread_registrations_by_name, io_name);
-      tr = (vlib_thread_registration_t *) p[0];
-      /* Otherwise, how did we get here */
-      ASSERT (tr && tr->count);
-      instances = tr->count;
-    }
-  else
-    {
-      /* manually assign */
-      ASSERT (instance_id < instances);
-    }
-
-  vec_validate (handoff_queue_elt_by_worker_index,
-                first_worker_index + num_workers - 1);
-
-  vec_validate_init_empty (congested_handoff_queue_by_worker_index,
-                           first_worker_index + num_workers - 1,
-                           (vlib_frame_queue_t *)(~0));
-
-  buffer_flags_template = dm->buffer_flags_template;
-
-  /* And handle them... */
-  while (1)
-    {
-      u32 n_buffers;
-      u32 mb_index;
-      uword n_rx_bytes = 0;
-      u32 n_trace, trace_cnt __attribute__((unused));
-      vlib_buffer_free_list_t * fl;
-      u32 hash;
-      u64 hash_key;
-      u8 efd_discard_burst;
-
-      vlib_worker_thread_barrier_check ();
-
-      /* Invoke callback if supplied */
-      if (PREDICT_FALSE(callback != NULL))
-          callback(vm);
-
-      if (PREDICT_FALSE(vec_len(dm->devices) != num_devices))
-      {
-        vec_reset_length(my_devices);
-        vec_foreach (xd, dm->devices)
-          {
-            if (((xd - dm->devices) % tr->count) == instance_id)
-              {
-                fprintf(stderr, "i/o thread %d (cpu %d) takes port %d\n",
-                        instance_id, (int) os_get_cpu_number(), (int) (xd - dm->devices));
-                vec_add1 (my_devices, xd);
-              }
-          }
-        num_devices = vec_len(dm->devices);
-      }
-
-      for (i = 0; i < vec_len (my_devices); i++)
-      {
-          xd = my_devices[i];
-
-	  if (!xd->admin_up)
-	    continue;
-
-          n_buffers = dpdk_rx_burst(dm, xd, 0 /* queue_id */);
-
-          if (n_buffers == 0)
-            {
-              /* check if EFD (dpdk) is enabled */
-              if (PREDICT_FALSE(dm->efd.enabled))
-                {
-                  /* reset a few stats */
-                  xd->efd_agent.last_poll_time = 0;
-                  xd->efd_agent.last_burst_sz = 0;
-                }
-              continue;
-            }
-
-          trace_cnt = n_trace = 0;
-          if (PREDICT_FALSE(vm->trace_main.trace_active_hint))
-            {
-              /*
-               * packet tracing is triggered on the dpdk-input node for
-               * ease-of-use. Re-fetch the node_runtime for dpdk-input
-               * in case it has changed.
-               */
-              node_trace = vlib_node_get_runtime (vm, dpdk_input_node.index);
-
-              vec_reset_length (xd->d_trace_buffers);
-              trace_cnt = n_trace = vlib_get_trace_count (vm, node_trace);
-            }
-        
-          /*
-           * DAW-FIXME: VMXNET3 device stop/start doesn't work, 
-           * therefore fake the stop in the dpdk driver by
-           * silently dropping all of the incoming pkts instead of 
-           * stopping the driver / hardware.
-           */
-          if (PREDICT_FALSE(xd->admin_up != 1))
-            {
-              for (mb_index = 0; mb_index < n_buffers; mb_index++)
-                rte_pktmbuf_free (xd->rx_vectors[queue_id][mb_index]);
-              continue;
-            }
-
-          /* reset EFD action for the burst */
-          efd_discard_burst = 0;
-          
-          /* Check for congestion if EFD (Early-Fast-Discard) is enabled
-           * in any mode (e.g. dpdk, monitor, or drop_all)
-           */
-          if (PREDICT_FALSE(dm->efd.enabled))
-            {
-              /* update EFD counters */
-              dpdk_efd_update_counters(xd, n_buffers, dm->efd.enabled);
-
-              if (PREDICT_FALSE(dm->efd.enabled & DPDK_EFD_DROPALL_ENABLED))
-                {
-                  /* drop all received packets */
-                  for (mb_index = 0; mb_index < n_buffers; mb_index++)
-                    rte_pktmbuf_free(xd->rx_vectors[queue_id][mb_index]);
-
-                  xd->efd_agent.discard_cnt += n_buffers;
-                  increment_efd_drop_counter(vm, 
-                                             DPDK_ERROR_VLAN_EFD_DROP_PKTS,
-                                             n_buffers);
-
-                  continue;
-                }
-
-              if (PREDICT_FALSE(xd->efd_agent.consec_full_frames_cnt >=
-                                dm->efd.consec_full_frames_hi_thresh))
-                {
-                  u32 device_queue_sz = rte_eth_rx_queue_count(xd->device_index,
-                                                               queue_id);
-                  if (device_queue_sz >= dm->efd.queue_hi_thresh)
-                    {
-                      /* dpdk device queue has reached the critical threshold */
-                      xd->efd_agent.congestion_cnt++;
-
-                      /* apply EFD to packets from the burst */
-                      efd_discard_burst = 1;
-                    }
-                }
-            }
-
-          fl = vlib_buffer_get_free_list 
-            (vm, VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
-        
-          mb_index = 0;
-
-          while (n_buffers > 0)
-            {
-              u32 bi0;
-              u8 next0, error0;
-              u32 l3_offset0;
-              vlib_buffer_t * b0, * b_seg, * b_chain = 0;
-              ethernet_header_t * h0;
-              u8 nb_seg = 1;
-              struct rte_mbuf *mb = xd->rx_vectors[queue_id][mb_index];
-              struct rte_mbuf *mb_seg = mb->next;
-                
-              if (PREDICT_TRUE(n_buffers > 1))
-                {
-                  struct rte_mbuf *pfmb = xd->rx_vectors[queue_id][mb_index+2];
-                  vlib_buffer_t *bp = vlib_buffer_from_rte_mbuf(pfmb);
-                  CLIB_PREFETCH (pfmb, CLIB_CACHE_LINE_BYTES, LOAD);
-                  CLIB_PREFETCH (bp, CLIB_CACHE_LINE_BYTES, STORE);
-                  CLIB_PREFETCH (bp->data, CLIB_CACHE_LINE_BYTES, LOAD);
-                }
-                
-              b0 = vlib_buffer_from_rte_mbuf(mb);
-
-              /* check whether EFD is looking for packets to discard */
-              if (PREDICT_FALSE(efd_discard_burst))
-                {
-                  u32 cntr_type;
-                  if (PREDICT_TRUE(cntr_type = is_efd_discardable(tm, b0, mb)))
-                    {
-                      rte_pktmbuf_free(mb);
-                      xd->efd_agent.discard_cnt++;
-                      increment_efd_drop_counter(vm, 
-                                                 cntr_type,
-                                                 1);
-
-                      n_buffers--;
-                      mb_index++;
-                      continue;
-                    }
-                }
-              
-              /* Prefetch one next segment if it exists */
-              if (PREDICT_FALSE(mb->nb_segs > 1))
-                {
-                  struct rte_mbuf *pfmb = mb->next;
-                  vlib_buffer_t *bp = vlib_buffer_from_rte_mbuf(pfmb);
-                  CLIB_PREFETCH (pfmb, CLIB_CACHE_LINE_BYTES, LOAD);
-                  CLIB_PREFETCH (bp, CLIB_CACHE_LINE_BYTES, STORE);
-                  b_chain = b0;
-                }
-
-              bi0 = vlib_get_buffer_index (vm, b0);
-              vlib_buffer_init_for_free_list (b0, fl);
-              b0->clone_count = 0;
-
-              dpdk_rx_next_and_error_from_mb_flags_x1 (xd, mb, b0,
-                                                       &next0, &error0);
-#ifdef RTE_LIBRTE_MBUF_EXT_RX_OLFLAGS
-              /*
-               * Clear overloaded TX offload flags when a DPDK driver
-               * is using them for RX flags (e.g. Cisco VIC Ethernet driver)
-               */
-              if (PREDICT_TRUE(trace_cnt == 0))
-                mb->ol_flags &= PKT_EXT_RX_CLR_TX_FLAGS_MASK;
-              else
-                trace_cnt--;
-#endif /* RTE_LIBRTE_MBUF_EXT_RX_OLFLAGS */
-
-              if (error0)
-                  clib_warning ("bi %d error %d", bi0, error0);
-
-              b0->error = 0;
-
-              l3_offset0 = ((next0 == DPDK_RX_NEXT_IP4_INPUT ||
-                             next0 == DPDK_RX_NEXT_IP6_INPUT || 
-                             next0 == DPDK_RX_NEXT_MPLS_INPUT) ? 
-                            sizeof (ethernet_header_t) : 0);
-
-              b0->current_data = l3_offset0;
-              /* Some drivers like fm10k receive frames with
-                 mb->data_off > RTE_PKTMBUF_HEADROOM */
-              b0->current_data += mb->data_off - RTE_PKTMBUF_HEADROOM;
-              b0->current_length = mb->data_len - l3_offset0;
-
-              b0->flags = buffer_flags_template;
-
-              if (VMWARE_LENGTH_BUG_WORKAROUND)
-                  b0->current_length -= 4;
-                
-              vnet_buffer(b0)->sw_if_index[VLIB_RX] = xd->vlib_sw_if_index;
-              vnet_buffer(b0)->sw_if_index[VLIB_TX] = (u32)~0;
-              vnet_buffer(b0)->handoff.next_index = next0;
-              n_rx_bytes += mb->pkt_len;
-
-              /* Process subsequent segments of multi-segment packets */
-              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);
-                  b_seg->clone_count = 0;
- 
-                  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;
-                  b0->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++;
-                }
-
-              /*
-               * 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);
- 
-              if (PREDICT_FALSE (n_trace > mb_index))
-                vec_add1 (xd->d_trace_buffers, bi0);
-
-              next_worker_index = first_worker_index;
-
-              /* 
-               * Force unknown traffic onto worker 0, 
-               * and into ethernet-input. $$$$ add more hashes.
-               */
-              h0 = (ethernet_header_t *) b0->data;
-
-              /* Compute ingress LB hash */
-              hash_key = eth_get_key(h0);
-              hash = (u32)clib_xxhash(hash_key);
-
-              if (PREDICT_TRUE (is_pow2(num_workers)))
-                next_worker_index += hash & (num_workers - 1);
-              else
-                next_worker_index += hash % num_workers;
-
-              /* if EFD is enabled and not already discarding from dpdk,
-               * check the worker ring/queue for congestion
-               */
-              if (PREDICT_FALSE(tm->efd.enabled && !efd_discard_burst))
-                {
-                  vlib_frame_queue_t *fq;
-
-                  /* fq will be valid if the ring is congested */
-                  fq = is_vlib_handoff_queue_congested(
-                      next_worker_index, tm->efd.queue_hi_thresh,
-                      congested_handoff_queue_by_worker_index);
-                  
-                  if (PREDICT_FALSE(fq != NULL))
-                    {
-                      u32 cntr_type;
-                      if (PREDICT_TRUE(cntr_type =
-                                       is_efd_discardable(tm, b0, mb)))
-                        {
-                          /* discard the packet */
-                          fq->enqueue_efd_discards++;
-                          increment_efd_drop_counter(vm, cntr_type, 1);
-                          rte_pktmbuf_free(mb);
-                          n_buffers--;
-                          mb_index++;
-                          continue;
-                        }
-                    }
-                }
-              
-              if (next_worker_index != current_worker_index)
-                {
-                  if (hf)
-                    hf->n_vectors = VLIB_FRAME_SIZE - n_left_to_next_worker;
-
-                  hf = dpdk_get_handoff_queue_elt(
-                           next_worker_index,
-                           handoff_queue_elt_by_worker_index);
-                      
-                  n_left_to_next_worker = VLIB_FRAME_SIZE - hf->n_vectors;
-                  to_next_worker = &hf->buffer_index[hf->n_vectors];
-                  current_worker_index = next_worker_index;
-                }
-              
-              /* enqueue to correct worker thread */
-              to_next_worker[0] = bi0;
-              to_next_worker++;
-              n_left_to_next_worker--;
-
-              if (n_left_to_next_worker == 0)
-                {
-                  hf->n_vectors = VLIB_FRAME_SIZE;
-                  vlib_put_handoff_queue_elt(hf);
-                  current_worker_index = ~0;
-                  handoff_queue_elt_by_worker_index[next_worker_index] = 0;
-                  hf = 0;
-                }
-                  
-              n_buffers--;
-              mb_index++;
-            }
-
-          if (PREDICT_FALSE (vec_len (xd->d_trace_buffers) > 0))
-            {
-              /* credit the trace to the trace node */
-              dpdk_rx_trace (dm, node_trace, xd, queue_id, xd->d_trace_buffers,
-                             vec_len (xd->d_trace_buffers));
-              vlib_set_trace_count (vm, node_trace, n_trace - vec_len (xd->d_trace_buffers));
-            }
-
-          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);
-
-          dpdk_worker_t * dw = vec_elt_at_index(dm->workers, cpu_index);
-          dw->aggregate_rx_packets += mb_index;
-        }
-
-      if (hf)
-        hf->n_vectors = VLIB_FRAME_SIZE - n_left_to_next_worker;
-
-      /* Ship frames to the worker nodes */
-      for (i = 0; i < vec_len (handoff_queue_elt_by_worker_index); i++)
-        {
-          if (handoff_queue_elt_by_worker_index[i])
-            {
-              hf = handoff_queue_elt_by_worker_index[i];
-              /* 
-               * It works better to let the handoff node
-               * rate-adapt, always ship the handoff queue element.
-               */
-              if (1 || hf->n_vectors == hf->last_n_vectors)
-                {
-                  vlib_put_handoff_queue_elt(hf);
-                  handoff_queue_elt_by_worker_index[i] = 0;
-                }
-              else
-                hf->last_n_vectors = hf->n_vectors;
-            }
-          congested_handoff_queue_by_worker_index[i] = (vlib_frame_queue_t *)(~0);
-        }
-      hf = 0;
-      current_worker_index = ~0;
-
-      vlib_increment_main_loop_counter (vm);
-    }
-}
-
-/*
- * This function is used when the main thread performs IO and feeds the
- * worker threads.
- */
-static uword
-dpdk_io_input (vlib_main_t * vm,
-               vlib_node_runtime_t * node,
-               vlib_frame_t * f)
-{
-  dpdk_main_t * dm = &dpdk_main;
-  dpdk_device_t * xd;
-  vlib_thread_main_t * tm = vlib_get_thread_main();
-  uword n_rx_packets = 0;
-  static vlib_frame_queue_elt_t ** handoff_queue_elt_by_worker_index;
-  static vlib_frame_queue_t ** congested_handoff_queue_by_worker_index = 0;
-  vlib_frame_queue_elt_t * hf = 0;
-  int i;
-  u32 n_left_to_next_worker = 0, * to_next_worker = 0;
-  u32 next_worker_index = 0;
-  u32 current_worker_index = ~0;
-  u32 cpu_index = os_get_cpu_number();
-  static int num_workers_set;
-  static u32 num_workers;
-  u16 queue_id = 0;
-  vlib_node_runtime_t * node_trace;
-  static u32 first_worker_index;
-  u32 buffer_flags_template;
-
-  if (PREDICT_FALSE(num_workers_set == 0))
-    {
-      uword * p;
-      vlib_thread_registration_t * tr;
-      /* Only the standard vnet worker threads are supported */
-      p = hash_get_mem (tm->thread_registrations_by_name, "workers");
-      tr = (vlib_thread_registration_t *) p[0];
-      if (tr) 
-        {
-          num_workers = tr->count;
-          first_worker_index = tr->first_index;
-        }
-      num_workers_set = 1;
-    }
-
-  if (PREDICT_FALSE(handoff_queue_elt_by_worker_index == 0))
-    {
-      vec_validate (handoff_queue_elt_by_worker_index, tm->n_vlib_mains - 1);
-      
-      vec_validate_init_empty (congested_handoff_queue_by_worker_index,
-                               first_worker_index + num_workers - 1,
-                               (vlib_frame_queue_t *)(~0));
-    }
-
-  /* packet tracing is triggered on the dpdk-input node for ease-of-use */
-  node_trace = vlib_node_get_runtime (vm, dpdk_input_node.index);
-
-  buffer_flags_template = dm->buffer_flags_template;
-
-  vec_foreach (xd, dm->devices)
-    {
-      u32 n_buffers;
-      u32 mb_index;
-      uword n_rx_bytes = 0;
-      u32 n_trace, trace_cnt __attribute__((unused));
-      vlib_buffer_free_list_t * fl;
-      u32 hash;
-      u64 hash_key;
-      u8 efd_discard_burst = 0;
-
-      if (!xd->admin_up)
-	continue;
-
-      n_buffers = dpdk_rx_burst(dm, xd, queue_id );
-
-      if (n_buffers == 0)
-        {
-          /* check if EFD (dpdk) is enabled */
-          if (PREDICT_FALSE(dm->efd.enabled))
-            {
-              /* reset a few stats */
-              xd->efd_agent.last_poll_time = 0;
-              xd->efd_agent.last_burst_sz = 0;
-            }
-          continue;
-        }
-
-      vec_reset_length (xd->d_trace_buffers);
-      trace_cnt = n_trace = vlib_get_trace_count (vm, node_trace);
-        
-      /*
-       * DAW-FIXME: VMXNET3 device stop/start doesn't work, 
-       * therefore fake the stop in the dpdk driver by
-       * silently dropping all of the incoming pkts instead of 
-       * stopping the driver / hardware.
-       */
-      if (PREDICT_FALSE(xd->admin_up != 1))
-        {
-          for (mb_index = 0; mb_index < n_buffers; mb_index++)
-            rte_pktmbuf_free (xd->rx_vectors[queue_id][mb_index]);
-          continue;
-        }
-
-      /* Check for congestion if EFD (Early-Fast-Discard) is enabled
-       * in any mode (e.g. dpdk, monitor, or drop_all)
-       */
-      if (PREDICT_FALSE(dm->efd.enabled))
-        {
-          /* update EFD counters */
-          dpdk_efd_update_counters(xd, n_buffers, dm->efd.enabled);
-
-          if (PREDICT_FALSE(dm->efd.enabled & DPDK_EFD_DROPALL_ENABLED))
-            {
-              /* discard all received packets */
-              for (mb_index = 0; mb_index < n_buffers; mb_index++)
-                rte_pktmbuf_free(xd->rx_vectors[queue_id][mb_index]);
-
-              xd->efd_agent.discard_cnt += n_buffers;
-              increment_efd_drop_counter(vm, 
-                                         DPDK_ERROR_VLAN_EFD_DROP_PKTS,
-                                         n_buffers);
-            
-              continue;
-            }
-          
-          if (PREDICT_FALSE(xd->efd_agent.consec_full_frames_cnt >=
-                            dm->efd.consec_full_frames_hi_thresh))
-            {
-              u32 device_queue_sz = rte_eth_rx_queue_count(xd->device_index,
-                                                           queue_id);
-              if (device_queue_sz >= dm->efd.queue_hi_thresh)
-                {
-                  /* dpdk device queue has reached the critical threshold */
-                  xd->efd_agent.congestion_cnt++;
-
-                  /* apply EFD to packets from the burst */
-                  efd_discard_burst = 1;
-                }
-            }
-        }
-      
-      fl = vlib_buffer_get_free_list 
-        (vm, VLIB_BUFFER_DEFAULT_FREE_LIST_INDEX);
-          
-      mb_index = 0;
-
-      while (n_buffers > 0)
-        {
-          u32 bi0;
-          u8 next0, error0;
-          u32 l3_offset0;
-          vlib_buffer_t * b0, * b_seg, * b_chain = 0;
-          ethernet_header_t * h0;
-          u8 nb_seg = 1;
-          struct rte_mbuf *mb = xd->rx_vectors[queue_id][mb_index];
-          struct rte_mbuf *mb_seg = mb->next;
-
-          if (PREDICT_TRUE(n_buffers > 1))
-            {
-              struct rte_mbuf *pfmb = xd->rx_vectors[queue_id][mb_index+2];
-              vlib_buffer_t *bp = vlib_buffer_from_rte_mbuf(pfmb);
-              CLIB_PREFETCH (pfmb, CLIB_CACHE_LINE_BYTES, LOAD);
-              CLIB_PREFETCH (bp, CLIB_CACHE_LINE_BYTES, STORE);
-              CLIB_PREFETCH (bp->data, CLIB_CACHE_LINE_BYTES, LOAD);
-            }
-
-          b0 = vlib_buffer_from_rte_mbuf(mb);
-
-          /* check whether EFD is looking for packets to discard */
-          if (PREDICT_FALSE(efd_discard_burst))
-            {
-              u32 cntr_type;
-              if (PREDICT_TRUE(cntr_type = is_efd_discardable(tm, b0, mb)))
-                {
-                  rte_pktmbuf_free(mb);
-                  xd->efd_agent.discard_cnt++;
-                  increment_efd_drop_counter(vm, 
-                                             cntr_type,
-                                             1);
-
-                  n_buffers--;
-                  mb_index++;
-                  continue;
-                }
-            }
-
-          /* Prefetch one next segment if it exists */
-          if (PREDICT_FALSE(mb->nb_segs > 1))
-            {
-              struct rte_mbuf *pfmb = mb->next;
-              vlib_buffer_t *bp = vlib_buffer_from_rte_mbuf(pfmb);
-              CLIB_PREFETCH (pfmb, CLIB_CACHE_LINE_BYTES, LOAD);
-              CLIB_PREFETCH (bp, CLIB_CACHE_LINE_BYTES, STORE);
-              b_chain = b0;
-            }
-
-          bi0 = vlib_get_buffer_index (vm, b0);
-          vlib_buffer_init_for_free_list (b0, fl);
-          b0->clone_count = 0;
-
-          dpdk_rx_next_and_error_from_mb_flags_x1 (xd, mb, b0,
-                                                   &next0, &error0);
-#ifdef RTE_LIBRTE_MBUF_EXT_RX_OLFLAGS
-          /*
-           * Clear overloaded TX offload flags when a DPDK driver
-           * is using them for RX flags (e.g. Cisco VIC Ethernet driver)
-           */
-          if (PREDICT_TRUE(trace_cnt == 0))
-            mb->ol_flags &= PKT_EXT_RX_CLR_TX_FLAGS_MASK;
-          else
-            trace_cnt--;
-#endif /* RTE_LIBRTE_MBUF_EXT_RX_OLFLAGS */
-
-          if (error0)
-            clib_warning ("bi %d error %d", bi0, error0);
-
-          b0->error = 0;
-
-          l3_offset0 = ((next0 == DPDK_RX_NEXT_IP4_INPUT ||
-                         next0 == DPDK_RX_NEXT_IP6_INPUT || 
-                         next0 == DPDK_RX_NEXT_MPLS_INPUT) ? 
-                        sizeof (ethernet_header_t) : 0);
-
-          b0->current_data = l3_offset0;
-          b0->current_length = mb->data_len - l3_offset0;
-
-          b0->flags = buffer_flags_template;
-                
-          if (VMWARE_LENGTH_BUG_WORKAROUND)
-              b0->current_length -= 4;
-
-          vnet_buffer(b0)->sw_if_index[VLIB_RX] = xd->vlib_sw_if_index;
-          vnet_buffer(b0)->sw_if_index[VLIB_TX] = (u32)~0;
-          vnet_buffer(b0)->handoff.next_index = next0;
-          n_rx_bytes += mb->pkt_len;
-
-          /* Process subsequent segments of multi-segment packets */
-          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);
-              b_seg->clone_count = 0;
- 
-              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;
-              b0->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++;
-            }
- 
-          /*
-           * 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);
- 
-          if (PREDICT_FALSE (n_trace > mb_index))
-            vec_add1 (xd->d_trace_buffers, bi0);
-
-          next_worker_index = first_worker_index;
-
-          /* 
-           * Force unknown traffic onto worker 0, 
-           * and into ethernet-input. $$$$ add more hashes.
-           */
-          h0 = (ethernet_header_t *) b0->data;
-
-          /* Compute ingress LB hash */
-          hash_key = eth_get_key(h0);
-          hash = (u32)clib_xxhash(hash_key);
-
-          if (PREDICT_TRUE (is_pow2(num_workers)))
-            next_worker_index += hash & (num_workers - 1);
-          else
-            next_worker_index += hash % num_workers;
-
-          /* if EFD is enabled and not already discarding from dpdk,
-           * check the worker ring/queue for congestion
-           */
-          if (PREDICT_FALSE(tm->efd.enabled && !efd_discard_burst))
-            {
-              vlib_frame_queue_t *fq;
-
-              /* fq will be valid if the ring is congested */
-              fq = is_vlib_handoff_queue_congested(
-                  next_worker_index, tm->efd.queue_hi_thresh,
-                  congested_handoff_queue_by_worker_index);
-              
-              if (PREDICT_FALSE(fq != NULL))
-                {
-                  u32 cntr_type;
-                  if (PREDICT_TRUE(cntr_type =
-                                   is_efd_discardable(tm, b0, mb)))
-                    {
-                      /* discard the packet */
-                      fq->enqueue_efd_discards++;
-                      increment_efd_drop_counter(vm, cntr_type, 1);
-                      rte_pktmbuf_free(mb);
-                      n_buffers--;
-                      mb_index++;
-                      continue;
-                    }
-                }
-            }
-          
-          if (next_worker_index != current_worker_index)
-            {
-              if (hf)
-                hf->n_vectors = VLIB_FRAME_SIZE - n_left_to_next_worker;
-
-              hf = dpdk_get_handoff_queue_elt(
-                     next_worker_index,
-                     handoff_queue_elt_by_worker_index);
-
-              n_left_to_next_worker = VLIB_FRAME_SIZE - hf->n_vectors;
-              to_next_worker = &hf->buffer_index[hf->n_vectors];
-              current_worker_index = next_worker_index;
-            }
-          
-          /* enqueue to correct worker thread */
-          to_next_worker[0] = bi0;
-          to_next_worker++;
-          n_left_to_next_worker--;
-
-          if (n_left_to_next_worker == 0)
-            {
-              hf->n_vectors = VLIB_FRAME_SIZE;
-              vlib_put_handoff_queue_elt(hf);
-              current_worker_index = ~0;
-              handoff_queue_elt_by_worker_index[next_worker_index] = 0;
-              hf = 0;
-            }
-          
-          n_buffers--;
-          mb_index++;
-        }
-
-      if (PREDICT_FALSE (vec_len (xd->d_trace_buffers) > 0))
-        {
-          /* credit the trace to the trace node */
-          dpdk_rx_trace (dm, node_trace, xd, queue_id, xd->d_trace_buffers,
-                         vec_len (xd->d_trace_buffers));
-          vlib_set_trace_count (vm, node_trace, n_trace - vec_len (xd->d_trace_buffers));
-        }
-
-      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);
-
-      dpdk_worker_t * dw = vec_elt_at_index(dm->workers, cpu_index);
-      dw->aggregate_rx_packets += mb_index;
-      n_rx_packets += mb_index;
-    }
-
-  if (hf)
-    hf->n_vectors = VLIB_FRAME_SIZE - n_left_to_next_worker;
-  
-  /* Ship frames to the worker nodes */
-  for (i = 0; i < vec_len (handoff_queue_elt_by_worker_index); i++)
-    {
-      if (handoff_queue_elt_by_worker_index[i])
-        {
-          hf = handoff_queue_elt_by_worker_index[i];
-          /* 
-           * It works better to let the handoff node
-           * rate-adapt, always ship the handoff queue element.
-           */
-          if (1 || hf->n_vectors == hf->last_n_vectors)
-            {
-              vlib_put_handoff_queue_elt(hf);
-              handoff_queue_elt_by_worker_index[i] = 0;
-            }
-          else
-            hf->last_n_vectors = hf->n_vectors;
-        }
-      congested_handoff_queue_by_worker_index[i] = (vlib_frame_queue_t *)(~0);
-    }
-  hf = 0;
-  current_worker_index = ~0;
-  return n_rx_packets;
-}
-
-VLIB_REGISTER_NODE (dpdk_io_input_node) = {
-  .function = dpdk_io_input,
-  .type = VLIB_NODE_TYPE_INPUT,
-  .name = "dpdk-io-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,
-
-  .n_next_nodes = DPDK_RX_N_NEXT,
-  .next_nodes = {
-    [DPDK_RX_NEXT_DROP] = "error-drop",
-    [DPDK_RX_NEXT_ETHERNET_INPUT] = "ethernet-input",
-    [DPDK_RX_NEXT_IP4_INPUT] = "ip4-input-no-checksum",
-    [DPDK_RX_NEXT_IP6_INPUT] = "ip6-input",
-    [DPDK_RX_NEXT_MPLS_INPUT] = "mpls-gre-input",
-  },
-};
-
-/*
  * set_efd_bitmap()
  * Based on the operation type, set lower/upper bits for the given index value
  */
diff --git a/vnet/vnet/devices/dpdk/threads.c b/vnet/vnet/devices/dpdk/threads.c
index c66db722394..48ee13d1eac 100644
--- a/vnet/vnet/devices/dpdk/threads.c
+++ b/vnet/vnet/devices/dpdk/threads.c
@@ -166,7 +166,7 @@ static inline int vlib_frame_queue_dequeue_internal (vlib_main_t *vm)
   return processed;
 }
 
-int dpdk_frame_queue_dequeue (vlib_main_t *vm) 
+int dpdk_frame_queue_dequeue (vlib_main_t *vm)
 {
   return vlib_frame_queue_dequeue_internal (vm);
 }
@@ -176,17 +176,12 @@ int dpdk_frame_queue_dequeue (vlib_main_t *vm)
  *
  * w
  *     Information for the current thread
- * io_name
- *     The name of thread performing dpdk device IO (if any). If there are no
- *     instances of that thread, then the current thread will do dpdk device
- *     polling. Ports will be divided among instances of the current thread.
  * callback
  *     If not null, this function will be called once during each main loop.
  */
 static_always_inline void
 dpdk_worker_thread_internal (vlib_main_t *vm,
-                             dpdk_worker_thread_callback_t callback,
-                             int have_io_threads)
+                             dpdk_worker_thread_callback_t callback)
 {
   vlib_node_main_t * nm = &vm->node_main;
   u64 cpu_time_now = clib_cpu_time_now ();
@@ -201,17 +196,13 @@ dpdk_worker_thread_internal (vlib_main_t *vm,
       if (PREDICT_FALSE(callback != NULL))
           callback(vm);
 
-      if (!have_io_threads)
-        {
-          vlib_node_runtime_t * n;
-          vec_foreach (n, nm->nodes_by_type[VLIB_NODE_TYPE_INPUT])
-            {
-              cpu_time_now = dispatch_node (vm, n, VLIB_NODE_TYPE_INPUT,
-                                            VLIB_NODE_STATE_POLLING, /* frame */ 0,
-                                            cpu_time_now);
-            }
-
-        }
+      vlib_node_runtime_t * n;
+      vec_foreach (n, nm->nodes_by_type[VLIB_NODE_TYPE_INPUT])
+	{
+	  cpu_time_now = dispatch_node (vm, n, VLIB_NODE_TYPE_INPUT,
+					VLIB_NODE_STATE_POLLING, /* frame */ 0,
+					cpu_time_now);
+	}
 
       if (_vec_len (nm->pending_frames))
         {
@@ -235,13 +226,9 @@ dpdk_worker_thread_internal (vlib_main_t *vm,
 }
 
 void dpdk_worker_thread (vlib_worker_thread_t * w,
-                         char *io_name,
                          dpdk_worker_thread_callback_t callback)
 {
   vlib_main_t *vm;
-  uword * p;
-  vlib_thread_main_t * tm = vlib_get_thread_main();
-  vlib_thread_registration_t * tr;
   dpdk_main_t * dm = &dpdk_main;
 
   vm = vlib_get_main();
@@ -252,24 +239,17 @@ void dpdk_worker_thread (vlib_worker_thread_t * w,
   clib_mem_set_heap (w->thread_mheap);
 
   /* Wait until the dpdk init sequence is complete */
-  while (dm->io_thread_release == 0)
+  while (dm->worker_thread_release == 0)
     vlib_worker_thread_barrier_check ();
 
-  /* any I/O threads? */
-  p = hash_get_mem (tm->thread_registrations_by_name, io_name);
-  tr = (vlib_thread_registration_t *)p[0];
-
-  if (tr && tr->count > 0)
-    dpdk_worker_thread_internal(vm, callback, /* have_io_threads */ 1);
-  else
-    dpdk_worker_thread_internal(vm, callback, /* have_io_threads */ 0);
+  dpdk_worker_thread_internal(vm, callback);
 }
 
 void dpdk_worker_thread_fn (void * arg)
 {
   vlib_worker_thread_t *w = (vlib_worker_thread_t *) arg;
   vlib_worker_thread_init (w);
-  dpdk_worker_thread (w, "io", 0);
+  dpdk_worker_thread (w, 0);
 }
 
 #if VIRL == 0
@@ -280,21 +260,6 @@ VLIB_REGISTER_THREAD (worker_thread_reg, static) = {
 };
 #endif
 
-void dpdk_io_thread_fn (void * arg)
-{
-  vlib_worker_thread_t *w = (vlib_worker_thread_t *) arg;
-  vlib_worker_thread_init (w);
-  dpdk_io_thread (w, 0, 0, "workers", 0);
-}
-
-#if VIRL == 0
-VLIB_REGISTER_THREAD (io_thread_reg, static) = {
-  .name = "io",
-  .short_name = "io",
-  .function = dpdk_io_thread_fn,
-};
-#endif
-
 static clib_error_t *
 dpdk_thread_init (vlib_main_t *vm)
 {
diff --git a/vnet/vnet/devices/dpdk/threads.h b/vnet/vnet/devices/dpdk/threads.h
index f2b0532b77c..c7d301bee21 100644
--- a/vnet/vnet/devices/dpdk/threads.h
+++ b/vnet/vnet/devices/dpdk/threads.h
@@ -20,7 +20,6 @@
 typedef void (*dpdk_worker_thread_callback_t) (vlib_main_t *vm);
 
 void dpdk_worker_thread (vlib_worker_thread_t * w,
-                         char *io_name,
                          dpdk_worker_thread_callback_t callback);
 
 int dpdk_frame_queue_dequeue (vlib_main_t *vm);
diff --git a/vnet/vnet/devices/dpdk/vhost_user.c b/vnet/vnet/devices/dpdk/vhost_user.c
index b1615b5aaf9..92b5d0e5e02 100644
--- a/vnet/vnet/devices/dpdk/vhost_user.c
+++ b/vnet/vnet/devices/dpdk/vhost_user.c
@@ -392,10 +392,7 @@ dpdk_create_vhost_user_if_internal (u32 * hw_if_index, u32 if_id, u8 *hwaddr)
       if (tm->n_vlib_mains == 1 && dpdk_input_node.state != VLIB_NODE_STATE_POLLING)
         vlib_node_set_state (vm, dpdk_input_node.index, VLIB_NODE_STATE_POLLING);
 
-      if (tm->n_vlib_mains > 1 && tm->main_thread_is_io_node)
-        vlib_node_set_state (vm, dpdk_io_input_node.index, VLIB_NODE_STATE_POLLING);
-
-      if (tm->n_vlib_mains > 1 && !tm->main_thread_is_io_node)
+      if (tm->n_vlib_mains > 1)
         vlib_node_set_state (vlib_mains[cpu], dpdk_input_node.index,
                              VLIB_NODE_STATE_POLLING);
       next_cpu++;
diff --git a/vnet/vnet/devices/virtio/vhost-user.c b/vnet/vnet/devices/virtio/vhost-user.c
index 4ed45e38853..afb2e0091cf 100644
--- a/vnet/vnet/devices/virtio/vhost-user.c
+++ b/vnet/vnet/devices/virtio/vhost-user.c
@@ -1648,7 +1648,7 @@ static void vhost_user_vui_register(vlib_main_t * vm, vhost_user_intf_t *vui)
   if (tm->n_vlib_mains == 1)
     vlib_node_set_state (vm, vhost_user_input_node.index,
                          VLIB_NODE_STATE_POLLING);
-  else if (!dm->have_io_threads)
+  else
     vlib_node_set_state (vlib_mains[cpu_index], vhost_user_input_node.index,
                          VLIB_NODE_STATE_POLLING);
 
@@ -1665,18 +1665,10 @@ int vhost_user_create_if(vnet_main_t * vnm, vlib_main_t * vm,
                          u8 *hwaddr)
 {
   vhost_user_intf_t * vui = NULL;
-  dpdk_main_t * dm = &dpdk_main;
-  vlib_thread_main_t * tm = vlib_get_thread_main();
   u32 sw_if_idx = ~0;
   int sockfd = -1;
   int rv = 0;
 
-  if (tm->n_vlib_mains > 1 && dm->have_io_threads)
-    {
-      clib_warning("vhost-user interfaces are not supported with multiple io threads");
-      return -1;
-    }
-
   if (is_server) {
       if ((rv = vhost_user_init_server_sock (sock_filename, &sockfd)) != 0) {
           return rv;