vhost: migrate to use device infra for worker thread assignment, rx-mode.

and add adaptive mode support to receive queue

- Migrate vhost to use device infra which does the interface/queue to worker
thread assignment.

- Retire vhost thread CLI and corresponding code which assigns interface/queue
to worker thread. set interface placement should be used instead to customize
the interface/queue to worker thread assignment.

- Retire vhost interrupt/polling option when creating vhost-user interface.
Instead, set interface rx-mode should be used.

- Add code in vnet_device_input_unassign_thread to change the node state
to interrupt if the last polling interface has left the worker thread for the
device of the corresponding interface/queue.

- Add adaptive mode support. The node state is set to interrupt initially.
When the scheduler detects a burst of traffic, it switches the input node to
polling. Then we inform the device that we don't need interrupt notification.
When the traffic subsides, the scheduler switches the input node back to
interrupt. Then we immediately tell the driver that we want interrupt
notification again.

- Remove some duplicate code in vlib/main.c

Change-Id: Id19bb1b9e50e6521c6464f470f5825c26924d3a8
Signed-off-by: Steven <sluong@cisco.com>

1 files changed, 20 insertions, 0 deletions

diff --git a/src/vnet/devices/devices.c b/src/vnet/devices/devices.c
index e71be602237..58c72077f24 100644
--- a/src/vnet/devices/devices.c
+++ b/src/vnet/devices/devices.c
@@ -150,6 +150,7 @@ vnet_hw_interface_assign_rx_thread (vnet_main_t * vnm, u32 hw_if_index,
   dq->dev_instance = hw->dev_instance;
   dq->queue_id = queue_id;
   dq->mode = VNET_HW_INTERFACE_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);
@@ -168,6 +169,7 @@ vnet_hw_interface_unassign_rx_thread (vnet_main_t * vnm, u32 hw_if_index,
   vnet_device_input_runtime_t *rt;
   vnet_device_and_queue_t *dq;
   uword old_thread_index;
+  vnet_hw_interface_rx_mode mode;
 
   if (hw->input_node_thread_index_by_queue == 0)
     return VNET_API_ERROR_INVALID_INTERFACE;
@@ -184,6 +186,7 @@ vnet_hw_interface_unassign_rx_thread (vnet_main_t * vnm, u32 hw_if_index,
   vec_foreach (dq, rt->devices_and_queues)
     if (dq->hw_if_index == hw_if_index && dq->queue_id == queue_id)
     {
+      mode = dq->mode;
       vec_del1 (rt->devices_and_queues, dq - rt->devices_and_queues);
       goto deleted;
     }
@@ -197,6 +200,23 @@ deleted:
 
   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_INTERFACE_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_INTERFACE_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;
 }