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

 /*
  * 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 <vnet/devices/devices.h>
 #include <vnet/feature/feature.h>
 #include <vnet/ip/ip.h>
 #include <vnet/ethernet/ethernet.h>

 vnet_device_main_t vnet_device_main;

 static uword
 device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 		 vlib_frame_t * frame)
 {
   return 0;
 }

 /* *INDENT-OFF* */
 VLIB_REGISTER_NODE (device_input_node) = {
   .function = device_input_fn,
   .name = "device-input",
   .runtime_data_bytes = sizeof (vnet_device_input_runtime_t),
   .type = VLIB_NODE_TYPE_INPUT,
   .state = VLIB_NODE_STATE_DISABLED,
   .n_next_nodes = VNET_DEVICE_INPUT_N_NEXT_NODES,
   .next_nodes = VNET_DEVICE_INPUT_NEXT_NODES,
 };

 /* Table defines how much we need to advance current data pointer
    in the buffer if we shortcut to l3 nodes */

 const u32 __attribute__((aligned (CLIB_CACHE_LINE_BYTES)))
 device_input_next_node_advance[((VNET_DEVICE_INPUT_N_NEXT_NODES /
 				CLIB_CACHE_LINE_BYTES) +1) * CLIB_CACHE_LINE_BYTES] =
 {
       [VNET_DEVICE_INPUT_NEXT_IP4_INPUT] = sizeof (ethernet_header_t),
       [VNET_DEVICE_INPUT_NEXT_IP4_NCS_INPUT] = sizeof (ethernet_header_t),
       [VNET_DEVICE_INPUT_NEXT_IP6_INPUT] = sizeof (ethernet_header_t),
       [VNET_DEVICE_INPUT_NEXT_MPLS_INPUT] = sizeof (ethernet_header_t),
 };

 const u32 __attribute__((aligned (CLIB_CACHE_LINE_BYTES)))
 device_input_next_node_flags[((VNET_DEVICE_INPUT_N_NEXT_NODES /
 				CLIB_CACHE_LINE_BYTES) +1) * CLIB_CACHE_LINE_BYTES] =
 {
       [VNET_DEVICE_INPUT_NEXT_IP4_INPUT] = VNET_BUFFER_F_L3_HDR_OFFSET_VALID,
       [VNET_DEVICE_INPUT_NEXT_IP4_NCS_INPUT] = VNET_BUFFER_F_L3_HDR_OFFSET_VALID,
       [VNET_DEVICE_INPUT_NEXT_IP6_INPUT] = VNET_BUFFER_F_L3_HDR_OFFSET_VALID,
       [VNET_DEVICE_INPUT_NEXT_MPLS_INPUT] = VNET_BUFFER_F_L3_HDR_OFFSET_VALID,
 };

 VNET_FEATURE_ARC_INIT (device_input, static) =
 {
   .arc_name  = "device-input",
   .start_nodes = VNET_FEATURES ("device-input"),
   .last_in_arc = "ethernet-input",
   .arc_index_ptr = &feature_main.device_input_feature_arc_index,
 };

 VNET_FEATURE_INIT (l2_patch, static) = {
   .arc_name = "device-input",
   .node_name = "l2-patch",
   .runs_before = VNET_FEATURES ("ethernet-input"),
 };

 VNET_FEATURE_INIT (worker_handoff, static) = {
   .arc_name = "device-input",
   .node_name = "worker-handoff",
   .runs_before = VNET_FEATURES ("ethernet-input"),
 };

 VNET_FEATURE_INIT (span_input, static) = {
   .arc_name = "device-input",
   .node_name = "span-input",
   .runs_before = VNET_FEATURES ("ethernet-input"),
 };

 VNET_FEATURE_INIT (p2p_ethernet_node, static) = {
   .arc_name = "device-input",
   .node_name = "p2p-ethernet-input",
   .runs_before = VNET_FEATURES ("ethernet-input"),
 };

 VNET_FEATURE_INIT (ethernet_input, static) = {
   .arc_name = "device-input",
   .node_name = "ethernet-input",
   .runs_before = 0, /* not before any other features */
 };
 /* *INDENT-ON* */

 static int
 vnet_device_queue_sort (void *a1, void *a2)
 {
   vnet_device_and_queue_t *dq1 = a1;
   vnet_device_and_queue_t *dq2 = a2;

   if (dq1->dev_instance > dq2->dev_instance)
     return 1;
   else if (dq1->dev_instance < dq2->dev_instance)
     return -1;
   else if (dq1->queue_id > dq2->queue_id)
     return 1;
   else if (dq1->queue_id < dq2->queue_id)
     return -1;
   else
     return 0;
 }

 static void
 vnet_device_queue_update (vnet_main_t * vnm, vnet_device_input_runtime_t * rt)
 {
   vnet_device_and_queue_t *dq;
   vnet_hw_interface_t *hw;

   vec_sort_with_function (rt->devices_and_queues, vnet_device_queue_sort);

   vec_foreach (dq, rt->devices_and_queues)
   {
     hw = vnet_get_hw_interface (vnm, dq->hw_if_index);
     vec_validate (hw->dq_runtime_index_by_queue, dq->queue_id);
     hw->dq_runtime_index_by_queue[dq->queue_id] = dq - rt->devices_and_queues;
   }
 }

 void
 vnet_hw_interface_assign_rx_thread (vnet_main_t * vnm, u32 hw_if_index,
 				    u16 queue_id, uword thread_index)
 {
   vnet_device_main_t *vdm = &vnet_device_main;
   vlib_main_t *vm, *vm0;
   vnet_device_input_runtime_t *rt;
   vnet_device_and_queue_t *dq;
   vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);

   ASSERT (hw->input_node_index > 0);

   if (vdm->first_worker_thread_index == 0)
     thread_index = 0;

   if (thread_index != 0 &&
       (thread_index < vdm->first_worker_thread_index ||
        thread_index > vdm->last_worker_thread_index))
     {
       thread_index = vdm->next_worker_thread_index++;
       if (vdm->next_worker_thread_index > vdm->last_worker_thread_index)
 	vdm->next_worker_thread_index = vdm->first_worker_thread_index;
     }

   vm = vlib_mains[thread_index];
   vm0 = vlib_get_main ();

   vlib_worker_thread_barrier_sync (vm0);

   rt = vlib_node_get_runtime_data (vm, hw->input_node_index);

   vec_add2 (rt->devices_and_queues, dq, 1);
   dq->hw_if_index = hw_if_index;
   dq->dev_instance = hw->dev_instance;
   dq->queue_id = queue_id;
   dq->mode = VNET_HW_IF_RX_MODE_POLLING;
   rt->enabled_node_state = VLIB_NODE_STATE_POLLING;

   vnet_device_queue_update (vnm, rt);
   vec_validate (hw->input_node_thread_index_by_queue, queue_id);
   vec_validate (hw->rx_mode_by_queue, queue_id);
   hw->input_node_thread_index_by_queue[queue_id] = thread_index;
   hw->rx_mode_by_queue[queue_id] = VNET_HW_IF_RX_MODE_POLLING;

   vlib_worker_thread_barrier_release (vm0);

   vlib_node_set_state (vm, hw->input_node_index, rt->enabled_node_state);
 }

 int
 vnet_hw_interface_unassign_rx_thread (vnet_main_t * vnm, u32 hw_if_index,
 				      u16 queue_id)
 {
   vlib_main_t *vm, *vm0;
   vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
   vnet_device_input_runtime_t *rt;
   vnet_device_and_queue_t *dq;
   uword old_thread_index;
   vnet_hw_if_rx_mode mode;

   if (hw->input_node_thread_index_by_queue == 0)
     return VNET_API_ERROR_INVALID_INTERFACE;

   if (vec_len (hw->input_node_thread_index_by_queue) < queue_id + 1)
     return VNET_API_ERROR_INVALID_INTERFACE;

   old_thread_index = hw->input_node_thread_index_by_queue[queue_id];

   vm = vlib_mains[old_thread_index];

   rt = vlib_node_get_runtime_data (vm, hw->input_node_index);

   vec_foreach (dq, rt->devices_and_queues)
     if (dq->hw_if_index == hw_if_index && dq->queue_id == queue_id)
     {
       mode = dq->mode;
       goto delete;
     }

   return VNET_API_ERROR_INVALID_INTERFACE;

 delete:

   vm0 = vlib_get_main ();
   vlib_worker_thread_barrier_sync (vm0);
   vec_del1 (rt->devices_and_queues, dq - rt->devices_and_queues);
   vnet_device_queue_update (vnm, rt);
   hw->rx_mode_by_queue[queue_id] = VNET_HW_IF_RX_MODE_UNKNOWN;
   vlib_worker_thread_barrier_release (vm0);

   if (vec_len (rt->devices_and_queues) == 0)
     vlib_node_set_state (vm, hw->input_node_index, VLIB_NODE_STATE_DISABLED);
   else if (mode == VNET_HW_IF_RX_MODE_POLLING)
     {
       /*
        * if the deleted interface is polling, we may need to set the node state
        * to interrupt if there is no more polling interface for this device's
        * corresponding thread. This is because mixed interfaces
        * (polling and interrupt), assigned to the same thread, set the
        * thread to polling prior to the deletion.
        */
       vec_foreach (dq, rt->devices_and_queues)
       {
 	if (dq->mode == VNET_HW_IF_RX_MODE_POLLING)
 	  return 0;
       }
       rt->enabled_node_state = VLIB_NODE_STATE_INTERRUPT;
       vlib_node_set_state (vm, hw->input_node_index, rt->enabled_node_state);
     }

   return 0;
 }


 int
 vnet_hw_interface_set_rx_mode (vnet_main_t * vnm, u32 hw_if_index,
 			       u16 queue_id, vnet_hw_if_rx_mode mode)
 {
   vlib_main_t *vm;
   uword thread_index;
   vnet_device_and_queue_t *dq;
   vlib_node_state_t enabled_node_state;
   ASSERT (mode < VNET_HW_IF_NUM_RX_MODES);
   vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
   vnet_device_input_runtime_t *rt;
   int is_polling = 0;

   if (mode == VNET_HW_IF_RX_MODE_DEFAULT)
     mode = hw->default_rx_mode;

   if (hw->input_node_thread_index_by_queue == 0 || hw->rx_mode_by_queue == 0)
     return VNET_API_ERROR_INVALID_INTERFACE;

   if (hw->rx_mode_by_queue[queue_id] == mode)
     return 0;

   if (mode != VNET_HW_IF_RX_MODE_POLLING &&
       (hw->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_INT_MODE) == 0)
     return VNET_API_ERROR_UNSUPPORTED;

   if ((vec_len (hw->input_node_thread_index_by_queue) < queue_id + 1) ||
       (vec_len (hw->rx_mode_by_queue) < queue_id + 1))
     return VNET_API_ERROR_INVALID_QUEUE;

   hw->rx_mode_by_queue[queue_id] = mode;
   thread_index = hw->input_node_thread_index_by_queue[queue_id];
   vm = vlib_mains[thread_index];

   rt = vlib_node_get_runtime_data (vm, hw->input_node_index);

   vec_foreach (dq, rt->devices_and_queues)
   {
     if (dq->hw_if_index == hw_if_index && dq->queue_id == queue_id)
       dq->mode = mode;
     if (dq->mode == VNET_HW_IF_RX_MODE_POLLING)
       is_polling = 1;
   }

   if (is_polling)
     enabled_node_state = VLIB_NODE_STATE_POLLING;
   else
     enabled_node_state = VLIB_NODE_STATE_INTERRUPT;

   if (rt->enabled_node_state != enabled_node_state)
     {
       rt->enabled_node_state = enabled_node_state;
       if (vlib_node_get_state (vm, hw->input_node_index) !=
 	  VLIB_NODE_STATE_DISABLED)
 	vlib_node_set_state (vm, hw->input_node_index, enabled_node_state);
     }

   return 0;
 }

 int
 vnet_hw_interface_get_rx_mode (vnet_main_t * vnm, u32 hw_if_index,
 			       u16 queue_id, vnet_hw_if_rx_mode * mode)
 {
   vlib_main_t *vm;
   uword thread_index;
   vnet_device_and_queue_t *dq;
   vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
   vnet_device_input_runtime_t *rt;

   if (hw->input_node_thread_index_by_queue == 0)
     return VNET_API_ERROR_INVALID_INTERFACE;

   if ((vec_len (hw->input_node_thread_index_by_queue) < queue_id + 1) ||
       (vec_len (hw->rx_mode_by_queue) < queue_id + 1))
     return VNET_API_ERROR_INVALID_QUEUE;

   thread_index = hw->input_node_thread_index_by_queue[queue_id];
   vm = vlib_mains[thread_index];

   rt = vlib_node_get_runtime_data (vm, hw->input_node_index);

   vec_foreach (dq, rt->devices_and_queues)
     if (dq->hw_if_index == hw_if_index && dq->queue_id == queue_id)
     {
       *mode = dq->mode;
       return 0;
     }

   return VNET_API_ERROR_INVALID_INTERFACE;
 }

 static clib_error_t *
 vnet_device_init (vlib_main_t * vm)
 {
   vnet_device_main_t *vdm = &vnet_device_main;
   vlib_thread_main_t *tm = vlib_get_thread_main ();
   vlib_thread_registration_t *tr;
   uword *p;

   vec_validate_aligned (vdm->workers, tm->n_vlib_mains - 1,
 			CLIB_CACHE_LINE_BYTES);

   p = hash_get_mem (tm->thread_registrations_by_name, "workers");
   tr = p ? (vlib_thread_registration_t *) p[0] : 0;
   if (tr && tr->count > 0)
     {
       vdm->first_worker_thread_index = tr->first_index;
       vdm->next_worker_thread_index = tr->first_index;
       vdm->last_worker_thread_index = tr->first_index + tr->count - 1;
     }
   return 0;
 }

 VLIB_INIT_FUNCTION (vnet_device_init);

 /*
  * fd.io coding-style-patch-verification: ON
  *
  * Local Variables:
  * eval: (c-set-style "gnu")
  * End:
  */
	/*
	* 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 <vnet/devices/devices.h>
	#include <vnet/feature/feature.h>
	#include <vnet/ip/ip.h>
	#include <vnet/ethernet/ethernet.h>

	vnet_device_main_t vnet_device_main;

	static uword
	device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
	vlib_frame_t * frame)
	{
	return 0;
	}

	/* INDENT-OFF */
	VLIB_REGISTER_NODE (device_input_node) = {
	.function = device_input_fn,
	.name = "device-input",
	.runtime_data_bytes = sizeof (vnet_device_input_runtime_t),
	.type = VLIB_NODE_TYPE_INPUT,
	.state = VLIB_NODE_STATE_DISABLED,
	.n_next_nodes = VNET_DEVICE_INPUT_N_NEXT_NODES,
	.next_nodes = VNET_DEVICE_INPUT_NEXT_NODES,
	};

	/* Table defines how much we need to advance current data pointer
	in the buffer if we shortcut to l3 nodes */

	const u32 __attribute__((aligned (CLIB_CACHE_LINE_BYTES)))
	device_input_next_node_advance[((VNET_DEVICE_INPUT_N_NEXT_NODES /
	CLIB_CACHE_LINE_BYTES) +1) * CLIB_CACHE_LINE_BYTES] =
	{
	[VNET_DEVICE_INPUT_NEXT_IP4_INPUT] = sizeof (ethernet_header_t),
	[VNET_DEVICE_INPUT_NEXT_IP4_NCS_INPUT] = sizeof (ethernet_header_t),
	[VNET_DEVICE_INPUT_NEXT_IP6_INPUT] = sizeof (ethernet_header_t),
	[VNET_DEVICE_INPUT_NEXT_MPLS_INPUT] = sizeof (ethernet_header_t),
	};

	const u32 __attribute__((aligned (CLIB_CACHE_LINE_BYTES)))
	device_input_next_node_flags[((VNET_DEVICE_INPUT_N_NEXT_NODES /
	CLIB_CACHE_LINE_BYTES) +1) * CLIB_CACHE_LINE_BYTES] =
	{
	[VNET_DEVICE_INPUT_NEXT_IP4_INPUT] = VNET_BUFFER_F_L3_HDR_OFFSET_VALID,
	[VNET_DEVICE_INPUT_NEXT_IP4_NCS_INPUT] = VNET_BUFFER_F_L3_HDR_OFFSET_VALID,
	[VNET_DEVICE_INPUT_NEXT_IP6_INPUT] = VNET_BUFFER_F_L3_HDR_OFFSET_VALID,
	[VNET_DEVICE_INPUT_NEXT_MPLS_INPUT] = VNET_BUFFER_F_L3_HDR_OFFSET_VALID,
	};

	VNET_FEATURE_ARC_INIT (device_input, static) =
	{
	.arc_name = "device-input",
	.start_nodes = VNET_FEATURES ("device-input"),
	.last_in_arc = "ethernet-input",
	.arc_index_ptr = &feature_main.device_input_feature_arc_index,
	};

	VNET_FEATURE_INIT (l2_patch, static) = {
	.arc_name = "device-input",
	.node_name = "l2-patch",
	.runs_before = VNET_FEATURES ("ethernet-input"),
	};

	VNET_FEATURE_INIT (worker_handoff, static) = {
	.arc_name = "device-input",
	.node_name = "worker-handoff",
	.runs_before = VNET_FEATURES ("ethernet-input"),
	};

	VNET_FEATURE_INIT (span_input, static) = {
	.arc_name = "device-input",
	.node_name = "span-input",
	.runs_before = VNET_FEATURES ("ethernet-input"),
	};

	VNET_FEATURE_INIT (p2p_ethernet_node, static) = {
	.arc_name = "device-input",
	.node_name = "p2p-ethernet-input",
	.runs_before = VNET_FEATURES ("ethernet-input"),
	};

	VNET_FEATURE_INIT (ethernet_input, static) = {
	.arc_name = "device-input",
	.node_name = "ethernet-input",
	.runs_before = 0, /* not before any other features */
	};
	/* INDENT-ON */

	static int
	vnet_device_queue_sort (void a1, void a2)
	{
	vnet_device_and_queue_t *dq1 = a1;
	vnet_device_and_queue_t *dq2 = a2;

	if (dq1->dev_instance > dq2->dev_instance)
	return 1;
	else if (dq1->dev_instance < dq2->dev_instance)
	return -1;
	else if (dq1->queue_id > dq2->queue_id)
	return 1;
	else if (dq1->queue_id < dq2->queue_id)
	return -1;
	else
	return 0;
	}

	static void
	vnet_device_queue_update (vnet_main_t * vnm, vnet_device_input_runtime_t * rt)
	{
	vnet_device_and_queue_t *dq;
	vnet_hw_interface_t *hw;

	vec_sort_with_function (rt->devices_and_queues, vnet_device_queue_sort);

	vec_foreach (dq, rt->devices_and_queues)
	{
	hw = vnet_get_hw_interface (vnm, dq->hw_if_index);
	vec_validate (hw->dq_runtime_index_by_queue, dq->queue_id);
	hw->dq_runtime_index_by_queue[dq->queue_id] = dq - rt->devices_and_queues;
	}
	}

	void
	vnet_hw_interface_assign_rx_thread (vnet_main_t * vnm, u32 hw_if_index,
	u16 queue_id, uword thread_index)
	{
	vnet_device_main_t *vdm = &vnet_device_main;
	vlib_main_t vm, vm0;
	vnet_device_input_runtime_t *rt;
	vnet_device_and_queue_t *dq;
	vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);

	ASSERT (hw->input_node_index > 0);

	if (vdm->first_worker_thread_index == 0)
	thread_index = 0;

	if (thread_index != 0 &&
	(thread_index < vdm->first_worker_thread_index \|\|
	thread_index > vdm->last_worker_thread_index))
	{
	thread_index = vdm->next_worker_thread_index++;
	if (vdm->next_worker_thread_index > vdm->last_worker_thread_index)
	vdm->next_worker_thread_index = vdm->first_worker_thread_index;
	}

	vm = vlib_mains[thread_index];
	vm0 = vlib_get_main ();

	vlib_worker_thread_barrier_sync (vm0);

	rt = vlib_node_get_runtime_data (vm, hw->input_node_index);

	vec_add2 (rt->devices_and_queues, dq, 1);
	dq->hw_if_index = hw_if_index;
	dq->dev_instance = hw->dev_instance;
	dq->queue_id = queue_id;
	dq->mode = VNET_HW_IF_RX_MODE_POLLING;
	rt->enabled_node_state = VLIB_NODE_STATE_POLLING;

	vnet_device_queue_update (vnm, rt);
	vec_validate (hw->input_node_thread_index_by_queue, queue_id);
	vec_validate (hw->rx_mode_by_queue, queue_id);
	hw->input_node_thread_index_by_queue[queue_id] = thread_index;
	hw->rx_mode_by_queue[queue_id] = VNET_HW_IF_RX_MODE_POLLING;

	vlib_worker_thread_barrier_release (vm0);

	vlib_node_set_state (vm, hw->input_node_index, rt->enabled_node_state);
	}

	int
	vnet_hw_interface_unassign_rx_thread (vnet_main_t * vnm, u32 hw_if_index,
	u16 queue_id)
	{
	vlib_main_t vm, vm0;
	vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
	vnet_device_input_runtime_t *rt;
	vnet_device_and_queue_t *dq;
	uword old_thread_index;
	vnet_hw_if_rx_mode mode;

	if (hw->input_node_thread_index_by_queue == 0)
	return VNET_API_ERROR_INVALID_INTERFACE;

	if (vec_len (hw->input_node_thread_index_by_queue) < queue_id + 1)
	return VNET_API_ERROR_INVALID_INTERFACE;

	old_thread_index = hw->input_node_thread_index_by_queue[queue_id];

	vm = vlib_mains[old_thread_index];

	rt = vlib_node_get_runtime_data (vm, hw->input_node_index);

	vec_foreach (dq, rt->devices_and_queues)
	if (dq->hw_if_index == hw_if_index && dq->queue_id == queue_id)
	{
	mode = dq->mode;
	goto delete;
	}

	return VNET_API_ERROR_INVALID_INTERFACE;

	delete:

	vm0 = vlib_get_main ();
	vlib_worker_thread_barrier_sync (vm0);
	vec_del1 (rt->devices_and_queues, dq - rt->devices_and_queues);
	vnet_device_queue_update (vnm, rt);
	hw->rx_mode_by_queue[queue_id] = VNET_HW_IF_RX_MODE_UNKNOWN;
	vlib_worker_thread_barrier_release (vm0);

	if (vec_len (rt->devices_and_queues) == 0)
	vlib_node_set_state (vm, hw->input_node_index, VLIB_NODE_STATE_DISABLED);
	else if (mode == VNET_HW_IF_RX_MODE_POLLING)
	{
	/*
	* if the deleted interface is polling, we may need to set the node state
	* to interrupt if there is no more polling interface for this device's
	* corresponding thread. This is because mixed interfaces
	* (polling and interrupt), assigned to the same thread, set the
	* thread to polling prior to the deletion.
	*/
	vec_foreach (dq, rt->devices_and_queues)
	{
	if (dq->mode == VNET_HW_IF_RX_MODE_POLLING)
	return 0;
	}
	rt->enabled_node_state = VLIB_NODE_STATE_INTERRUPT;
	vlib_node_set_state (vm, hw->input_node_index, rt->enabled_node_state);
	}

	return 0;
	}


	int
	vnet_hw_interface_set_rx_mode (vnet_main_t * vnm, u32 hw_if_index,
	u16 queue_id, vnet_hw_if_rx_mode mode)
	{
	vlib_main_t *vm;
	uword thread_index;
	vnet_device_and_queue_t *dq;
	vlib_node_state_t enabled_node_state;
	ASSERT (mode < VNET_HW_IF_NUM_RX_MODES);
	vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
	vnet_device_input_runtime_t *rt;
	int is_polling = 0;

	if (mode == VNET_HW_IF_RX_MODE_DEFAULT)
	mode = hw->default_rx_mode;

	if (hw->input_node_thread_index_by_queue == 0 \|\| hw->rx_mode_by_queue == 0)
	return VNET_API_ERROR_INVALID_INTERFACE;

	if (hw->rx_mode_by_queue[queue_id] == mode)
	return 0;

	if (mode != VNET_HW_IF_RX_MODE_POLLING &&
	(hw->flags & VNET_HW_INTERFACE_FLAG_SUPPORTS_INT_MODE) == 0)
	return VNET_API_ERROR_UNSUPPORTED;

	if ((vec_len (hw->input_node_thread_index_by_queue) < queue_id + 1) \|\|
	(vec_len (hw->rx_mode_by_queue) < queue_id + 1))
	return VNET_API_ERROR_INVALID_QUEUE;

	hw->rx_mode_by_queue[queue_id] = mode;
	thread_index = hw->input_node_thread_index_by_queue[queue_id];
	vm = vlib_mains[thread_index];

	rt = vlib_node_get_runtime_data (vm, hw->input_node_index);

	vec_foreach (dq, rt->devices_and_queues)
	{
	if (dq->hw_if_index == hw_if_index && dq->queue_id == queue_id)
	dq->mode = mode;
	if (dq->mode == VNET_HW_IF_RX_MODE_POLLING)
	is_polling = 1;
	}

	if (is_polling)
	enabled_node_state = VLIB_NODE_STATE_POLLING;
	else
	enabled_node_state = VLIB_NODE_STATE_INTERRUPT;

	if (rt->enabled_node_state != enabled_node_state)
	{
	rt->enabled_node_state = enabled_node_state;
	if (vlib_node_get_state (vm, hw->input_node_index) !=
	VLIB_NODE_STATE_DISABLED)
	vlib_node_set_state (vm, hw->input_node_index, enabled_node_state);
	}

	return 0;
	}

	int
	vnet_hw_interface_get_rx_mode (vnet_main_t * vnm, u32 hw_if_index,
	u16 queue_id, vnet_hw_if_rx_mode * mode)
	{
	vlib_main_t *vm;
	uword thread_index;
	vnet_device_and_queue_t *dq;
	vnet_hw_interface_t *hw = vnet_get_hw_interface (vnm, hw_if_index);
	vnet_device_input_runtime_t *rt;

	if (hw->input_node_thread_index_by_queue == 0)
	return VNET_API_ERROR_INVALID_INTERFACE;

	if ((vec_len (hw->input_node_thread_index_by_queue) < queue_id + 1) \|\|
	(vec_len (hw->rx_mode_by_queue) < queue_id + 1))
	return VNET_API_ERROR_INVALID_QUEUE;

	thread_index = hw->input_node_thread_index_by_queue[queue_id];
	vm = vlib_mains[thread_index];

	rt = vlib_node_get_runtime_data (vm, hw->input_node_index);

	vec_foreach (dq, rt->devices_and_queues)
	if (dq->hw_if_index == hw_if_index && dq->queue_id == queue_id)
	{
	*mode = dq->mode;
	return 0;
	}

	return VNET_API_ERROR_INVALID_INTERFACE;
	}

	static clib_error_t *
	vnet_device_init (vlib_main_t * vm)
	{
	vnet_device_main_t *vdm = &vnet_device_main;
	vlib_thread_main_t *tm = vlib_get_thread_main ();
	vlib_thread_registration_t *tr;
	uword *p;

	vec_validate_aligned (vdm->workers, tm->n_vlib_mains - 1,
	CLIB_CACHE_LINE_BYTES);

	p = hash_get_mem (tm->thread_registrations_by_name, "workers");
	tr = p ? (vlib_thread_registration_t *) p[0] : 0;
	if (tr && tr->count > 0)
	{
	vdm->first_worker_thread_index = tr->first_index;
	vdm->next_worker_thread_index = tr->first_index;
	vdm->last_worker_thread_index = tr->first_index + tr->count - 1;
	}
	return 0;
	}

	VLIB_INIT_FUNCTION (vnet_device_init);

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