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path: root/src/vnet/handoff.c
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id='n554' href='#n554'>554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594
/*
 * Copyright (c) 2016 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/xxhash.h>
#include <vlib/threads.h>
#include <vnet/handoff.h>
#include <vnet/feature/feature.h>

typedef struct
{
  uword *workers_bitmap;
  u32 *workers;
} per_inteface_handoff_data_t;

typedef struct
{
  u32 cached_next_index;
  u32 num_workers;
  u32 first_worker_index;

  per_inteface_handoff_data_t *if_data;

  /* Worker handoff index */
  u32 frame_queue_index;

  /* convenience variables */
  vlib_main_t *vlib_main;
  vnet_main_t *vnet_main;

    u64 (*hash_fn) (ethernet_header_t *);
} handoff_main_t;

handoff_main_t handoff_main;
vlib_node_registration_t handoff_dispatch_node;

typedef struct
{
  u32 sw_if_index;
  u32 next_worker_index;
  u32 buffer_index;
} worker_handoff_trace_t;

/* packet trace format function */
static u8 *
format_worker_handoff_trace (u8 * s, va_list * args)
{
  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  worker_handoff_trace_t *t = va_arg (*args, worker_handoff_trace_t *);

  s =
    format (s, "worker-handoff: sw_if_index %d, next_worker %d, buffer 0x%x",
	    t->sw_if_index, t->next_worker_index, t->buffer_index);
  return s;
}

vlib_node_registration_t handoff_node;

static uword
worker_handoff_node_fn (vlib_main_t * vm,
			vlib_node_runtime_t * node, vlib_frame_t * frame)
{
  handoff_main_t *hm = &handoff_main;
  vlib_thread_main_t *tm = vlib_get_thread_main ();
  u32 n_left_from, *from;
  static __thread vlib_frame_queue_elt_t **handoff_queue_elt_by_worker_index;
  static __thread 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;

  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,
			       hm->first_worker_index + hm->num_workers - 1,
			       (vlib_frame_queue_t *) (~0));
    }

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;

  while (n_left_from > 0)
    {
      u32 bi0;
      vlib_buffer_t *b0;
      u32 sw_if_index0;
      u32 hash;
      u64 hash_key;
      per_inteface_handoff_data_t *ihd0;
      u32 index0;

      bi0 = from[0];
      from += 1;
      n_left_from -= 1;

      b0 = vlib_get_buffer (vm, bi0);
      sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
      ASSERT (hm->if_data);
      ihd0 = vec_elt_at_index (hm->if_data, sw_if_index0);

      next_worker_index = hm->first_worker_index;

      /*
       * Force unknown traffic onto worker 0,
       * and into ethernet-input. $$$$ add more hashes.
       */

      /* Compute ingress LB hash */
      hash_key = hm->hash_fn ((ethernet_header_t *) b0->data);
      hash = (u32) clib_xxhash (hash_key);

      /* if input node did not specify next index, then packet
         should go to eternet-input */
      if (PREDICT_FALSE ((b0->flags & BUFFER_HANDOFF_NEXT_VALID) == 0))
	vnet_buffer (b0)->handoff.next_index =
	  HANDOFF_DISPATCH_NEXT_ETHERNET_INPUT;
      else if (vnet_buffer (b0)->handoff.next_index ==
	       HANDOFF_DISPATCH_NEXT_IP4_INPUT
	       || vnet_buffer (b0)->handoff.next_index ==
	       HANDOFF_DISPATCH_NEXT_IP6_INPUT
	       || vnet_buffer (b0)->handoff.next_index ==
	       HANDOFF_DISPATCH_NEXT_MPLS_INPUT)
	vlib_buffer_advance (b0, (sizeof (ethernet_header_t)));

      if (PREDICT_TRUE (is_pow2 (vec_len (ihd0->workers))))
	index0 = hash & (vec_len (ihd0->workers) - 1);
      else
	index0 = hash % vec_len (ihd0->workers);

      next_worker_index += ihd0->workers[index0];

      if (next_worker_index != current_worker_index)
	{
	  if (hf)
	    hf->n_vectors = VLIB_FRAME_SIZE - n_left_to_next_worker;

	  hf = vlib_get_worker_handoff_queue_elt (hm->frame_queue_index,
						  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_frame_queue_elt (hf);
	  current_worker_index = ~0;
	  handoff_queue_elt_by_worker_index[next_worker_index] = 0;
	  hf = 0;
	}

      if (PREDICT_FALSE ((node->flags & VLIB_NODE_FLAG_TRACE)
			 && (b0->flags & VLIB_BUFFER_IS_TRACED)))
	{
	  worker_handoff_trace_t *t =
	    vlib_add_trace (vm, node, b0, sizeof (*t));
	  t->sw_if_index = sw_if_index0;
	  t->next_worker_index = next_worker_index - hm->first_worker_index;
	  t->buffer_index = bi0;
	}

    }

  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_frame_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 frame->n_vectors;
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (worker_handoff_node) = {
  .function = worker_handoff_node_fn,
  .name = "worker-handoff",
  .vector_size = sizeof (u32),
  .format_trace = format_worker_handoff_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,

  .n_next_nodes = 1,
  .next_nodes = {
    [0] = "error-drop",
  },
};

VLIB_NODE_FUNCTION_MULTIARCH (worker_handoff_node, worker_handoff_node_fn)
/* *INDENT-ON* */

int
interface_handoff_enable_disable (vlib_main_t * vm, u32 sw_if_index,
				  uword * bitmap, int enable_disable)
{
  handoff_main_t *hm = &handoff_main;
  vnet_sw_interface_t *sw;
  vnet_main_t *vnm = vnet_get_main ();
  per_inteface_handoff_data_t *d;
  int i, rv = 0;

  if (pool_is_free_index (vnm->interface_main.sw_interfaces, sw_if_index))
    return VNET_API_ERROR_INVALID_SW_IF_INDEX;

  sw = vnet_get_sw_interface (vnm, sw_if_index);
  if (sw->type != VNET_SW_INTERFACE_TYPE_HARDWARE)
    return VNET_API_ERROR_INVALID_SW_IF_INDEX;

  if (clib_bitmap_last_set (bitmap) >= hm->num_workers)
    return VNET_API_ERROR_INVALID_WORKER;

  if (hm->frame_queue_index == ~0)
    hm->frame_queue_index =
      vlib_frame_queue_main_init (handoff_dispatch_node.index, 0);

  vec_validate (hm->if_data, sw_if_index);
  d = vec_elt_at_index (hm->if_data, sw_if_index);

  vec_free (d->workers);
  vec_free (d->workers_bitmap);

  if (enable_disable)
    {
      d->workers_bitmap = bitmap;
      /* *INDENT-OFF* */
      clib_bitmap_foreach (i, bitmap,
	({
	  vec_add1(d->workers, i);
	}));
      /* *INDENT-ON* */
    }

  vnet_feature_enable_disable ("device-input", "worker-handoff",
			       sw_if_index, enable_disable, 0, 0);
  return rv;
}

static clib_error_t *
set_interface_handoff_command_fn (vlib_main_t * vm,
				  unformat_input_t * input,
				  vlib_cli_command_t * cmd)
{
  handoff_main_t *hm = &handoff_main;
  u32 sw_if_index = ~0;
  int enable_disable = 1;
  uword *bitmap = 0;
  u32 sym = ~0;

  int rv = 0;

  while (unformat_check_input (input) != UNFORMAT_END_OF_INPUT)
    {
      if (unformat (input, "disable"))
	enable_disable = 0;
      else if (unformat (input, "workers %U", unformat_bitmap_list, &bitmap))
	;
      else if (unformat (input, "%U", unformat_vnet_sw_interface,
			 vnet_get_main (), &sw_if_index))
	;
      else if (unformat (input, "symmetrical"))
	sym = 1;
      else if (unformat (input, "asymmetrical"))
	sym = 0;
      else
	break;
    }

  if (sw_if_index == ~0)
    return clib_error_return (0, "Please specify an interface...");

  if (bitmap == 0)
    return clib_error_return (0, "Please specify list of workers...");

  rv =
    interface_handoff_enable_disable (vm, sw_if_index, bitmap,
				      enable_disable);

  switch (rv)
    {
    case 0:
      break;

    case VNET_API_ERROR_INVALID_SW_IF_INDEX:
      return clib_error_return (0, "Invalid interface");
      break;

    case VNET_API_ERROR_INVALID_WORKER:
      return clib_error_return (0, "Invalid worker(s)");
      break;

    case VNET_API_ERROR_UNIMPLEMENTED:
      return clib_error_return (0,
				"Device driver doesn't support redirection");
      break;

    default:
      return clib_error_return (0, "unknown return value %d", rv);
    }

  if (sym == 1)
    hm->hash_fn = eth_get_sym_key;
  else if (sym == 0)
    hm->hash_fn = eth_get_key;

  return 0;
}

/* *INDENT-OFF* */
VLIB_CLI_COMMAND (set_interface_handoff_command, static) = {
  .path = "set interface handoff",
  .short_help =
  "set interface handoff <interface-name> workers <workers-list> [symmetrical|asymmetrical]",
  .function = set_interface_handoff_command_fn,
};
/* *INDENT-ON* */

typedef struct
{
  u32 buffer_index;
  u32 next_index;
  u32 sw_if_index;
} handoff_dispatch_trace_t;

/* packet trace format function */
static u8 *
format_handoff_dispatch_trace (u8 * s, va_list * args)
{
  CLIB_UNUSED (vlib_main_t * vm) = va_arg (*args, vlib_main_t *);
  CLIB_UNUSED (vlib_node_t * node) = va_arg (*args, vlib_node_t *);
  handoff_dispatch_trace_t *t = va_arg (*args, handoff_dispatch_trace_t *);

  s = format (s, "handoff-dispatch: sw_if_index %d next_index %d buffer 0x%x",
	      t->sw_if_index, t->next_index, t->buffer_index);
  return s;
}

#define foreach_handoff_dispatch_error \
_(EXAMPLE, "example packets")

typedef enum
{
#define _(sym,str) HANDOFF_DISPATCH_ERROR_##sym,
  foreach_handoff_dispatch_error
#undef _
    HANDOFF_DISPATCH_N_ERROR,
} handoff_dispatch_error_t;

static char *handoff_dispatch_error_strings[] = {
#define _(sym,string) string,
  foreach_handoff_dispatch_error
#undef _
};

static uword
handoff_dispatch_node_fn (vlib_main_t * vm,
			  vlib_node_runtime_t * node, vlib_frame_t * frame)
{
  u32 n_left_from, *from, *to_next;
  handoff_dispatch_next_t next_index;

  from = vlib_frame_vector_args (frame);
  n_left_from = frame->n_vectors;
  next_index = node->cached_next_index;

  while (n_left_from > 0)
    {
      u32 n_left_to_next;

      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);

      while (n_left_from >= 4 && n_left_to_next >= 2)
	{
	  u32 bi0, bi1;
	  vlib_buffer_t *b0, *b1;
	  u32 next0, next1;
	  u32 sw_if_index0, sw_if_index1;

	  /* Prefetch next iteration. */
	  {
	    vlib_buffer_t *p2, *p3;

	    p2 = vlib_get_buffer (vm, from[2]);
	    p3 = vlib_get_buffer (vm, from[3]);

	    vlib_prefetch_buffer_header (p2, LOAD);
	    vlib_prefetch_buffer_header (p3, LOAD);
	  }

	  /* speculatively enqueue b0 and b1 to the current next frame */
	  to_next[0] = bi0 = from[0];
	  to_next[1] = bi1 = from[1];
	  from += 2;
	  to_next += 2;
	  n_left_from -= 2;
	  n_left_to_next -= 2;

	  b0 = vlib_get_buffer (vm, bi0);
	  b1 = vlib_get_buffer (vm, bi1);

	  next0 = vnet_buffer (b0)->handoff.next_index;
	  next1 = vnet_buffer (b1)->handoff.next_index;

	  if (PREDICT_FALSE (vm->trace_main.trace_active_hint))
	    {
	      if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
		{
		  vlib_trace_buffer (vm, node, next0, b0,	/* follow_chain */
				     0);
		  handoff_dispatch_trace_t *t =
		    vlib_add_trace (vm, node, b0, sizeof (*t));
		  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
		  t->sw_if_index = sw_if_index0;
		  t->next_index = next0;
		  t->buffer_index = bi0;
		}
	      if (PREDICT_FALSE (b1->flags & VLIB_BUFFER_IS_TRACED))
		{
		  vlib_trace_buffer (vm, node, next1, b1,	/* follow_chain */
				     0);
		  handoff_dispatch_trace_t *t =
		    vlib_add_trace (vm, node, b1, sizeof (*t));
		  sw_if_index1 = vnet_buffer (b1)->sw_if_index[VLIB_RX];
		  t->sw_if_index = sw_if_index1;
		  t->next_index = next1;
		  t->buffer_index = bi1;
		}
	    }

	  /* verify speculative enqueues, maybe switch current next frame */
	  vlib_validate_buffer_enqueue_x2 (vm, node, next_index,
					   to_next, n_left_to_next,
					   bi0, bi1, next0, next1);
	}

      while (n_left_from > 0 && n_left_to_next > 0)
	{
	  u32 bi0;
	  vlib_buffer_t *b0;
	  u32 next0;
	  u32 sw_if_index0;

	  /* speculatively enqueue b0 to the current next frame */
	  bi0 = from[0];
	  to_next[0] = bi0;
	  from += 1;
	  to_next += 1;
	  n_left_from -= 1;
	  n_left_to_next -= 1;

	  b0 = vlib_get_buffer (vm, bi0);

	  next0 = vnet_buffer (b0)->handoff.next_index;

	  if (PREDICT_FALSE (vm->trace_main.trace_active_hint))
	    {
	      if (PREDICT_FALSE (b0->flags & VLIB_BUFFER_IS_TRACED))
		{
		  vlib_trace_buffer (vm, node, next0, b0,	/* follow_chain */
				     0);
		  handoff_dispatch_trace_t *t =
		    vlib_add_trace (vm, node, b0, sizeof (*t));
		  sw_if_index0 = vnet_buffer (b0)->sw_if_index[VLIB_RX];
		  t->sw_if_index = sw_if_index0;
		  t->next_index = next0;
		  t->buffer_index = bi0;
		}
	    }

	  /* verify speculative enqueue, maybe switch current next frame */
	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index,
					   to_next, n_left_to_next,
					   bi0, next0);
	}

      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
    }

  return frame->n_vectors;
}

/* *INDENT-OFF* */
VLIB_REGISTER_NODE (handoff_dispatch_node) = {
  .function = handoff_dispatch_node_fn,
  .name = "handoff-dispatch",
  .vector_size = sizeof (u32),
  .format_trace = format_handoff_dispatch_trace,
  .type = VLIB_NODE_TYPE_INTERNAL,
  .flags = VLIB_NODE_FLAG_IS_HANDOFF,

  .n_errors = ARRAY_LEN(handoff_dispatch_error_strings),
  .error_strings = handoff_dispatch_error_strings,

  .n_next_nodes = HANDOFF_DISPATCH_N_NEXT,

  .next_nodes = {
        [HANDOFF_DISPATCH_NEXT_DROP] = "error-drop",
        [HANDOFF_DISPATCH_NEXT_ETHERNET_INPUT] = "ethernet-input",
        [HANDOFF_DISPATCH_NEXT_IP4_INPUT] = "ip4-input-no-checksum",
        [HANDOFF_DISPATCH_NEXT_IP6_INPUT] = "ip6-input",
        [HANDOFF_DISPATCH_NEXT_MPLS_INPUT] = "mpls-input",
  },
};

VLIB_NODE_FUNCTION_MULTIARCH (handoff_dispatch_node, handoff_dispatch_node_fn)
/* *INDENT-ON* */

clib_error_t *
handoff_init (vlib_main_t * vm)
{
  handoff_main_t *hm = &handoff_main;
  vlib_thread_main_t *tm = vlib_get_thread_main ();
  clib_error_t *error;
  uword *p;

  if ((error = vlib_call_init_function (vm, threads_init)))
    return error;

  vlib_thread_registration_t *tr;
  /* Only the standard vnet worker threads are supported */
  p = hash_get_mem (tm->thread_registrations_by_name, "workers");
  if (p)
    {
      tr = (vlib_thread_registration_t *) p[0];
      if (tr)
	{
	  hm->num_workers = tr->count;
	  hm->first_worker_index = tr->first_index;
	}
    }

  hm->hash_fn = eth_get_key;

  hm->vlib_main = vm;
  hm->vnet_main = &vnet_main;

  hm->frame_queue_index = ~0;

  return 0;
}

VLIB_INIT_FUNCTION (handoff_init);

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