devices: af-packet v3 support

Type: feature

CPU usage ~20% less than v2.
Performance improvement 20% more than v2.
High vector rate.

Change-Id: I24bc594200f42664b59d07b44d44578e61068bbc
Signed-off-by: Mohsin Kazmi <sykazmi@cisco.com>

1 files changed, 190 insertions, 157 deletions

diff --git a/src/vnet/devices/af_packet/node.c b/src/vnet/devices/af_packet/node.c
index efe701642bb..229e0501af7 100644
--- a/src/vnet/devices/af_packet/node.c
+++ b/src/vnet/devices/af_packet/node.c
@@ -51,7 +51,10 @@ typedef struct
   u32 next_index;
   u32 hw_if_index;
   int block;
-  struct tpacket2_hdr tph;
+  u32 num_pkts;
+  void *block_start;
+  block_desc_t bd;
+  tpacket3_hdr_t tph;
 } af_packet_input_trace_t;
 
 static u8 *
@@ -65,26 +68,27 @@ format_af_packet_input_trace (u8 * s, va_list * args)
   s = format (s, "af_packet: hw_if_index %d next-index %d",
 	      t->hw_if_index, t->next_index);
 
+  s = format (s,
+	      "\n%Ublock %u:\n%Uaddress %p version %u seq_num %lu"
+	      " num_pkts %u",
+	      format_white_space, indent + 2, t->block, format_white_space,
+	      indent + 4, t->block_start, t->bd.version, t->bd.hdr.bh1.seq_num,
+	      t->num_pkts);
   s =
     format (s,
-	    "\n%Utpacket2_hdr:\n%Ustatus 0x%x len %u snaplen %u mac %u net %u"
+	    "\n%Utpacket3_hdr:\n%Ustatus 0x%x len %u snaplen %u mac %u net %u"
 	    "\n%Usec 0x%x nsec 0x%x vlan %U"
 #ifdef TP_STATUS_VLAN_TPID_VALID
 	    " vlan_tpid %u"
 #endif
 	    ,
-	    format_white_space, indent + 2,
-	    format_white_space, indent + 4,
-	    t->tph.tp_status,
-	    t->tph.tp_len,
-	    t->tph.tp_snaplen,
-	    t->tph.tp_mac,
-	    t->tph.tp_net,
-	    format_white_space, indent + 4,
-	    t->tph.tp_sec,
-	    t->tph.tp_nsec, format_ethernet_vlan_tci, t->tph.tp_vlan_tci
+	    format_white_space, indent + 2, format_white_space, indent + 4,
+	    t->tph.tp_status, t->tph.tp_len, t->tph.tp_snaplen, t->tph.tp_mac,
+	    t->tph.tp_net, format_white_space, indent + 4, t->tph.tp_sec,
+	    t->tph.tp_nsec, format_ethernet_vlan_tci, t->tph.hv1.tp_vlan_tci
 #ifdef TP_STATUS_VLAN_TPID_VALID
-	    , t->tph.tp_vlan_tpid
+	    ,
+	    t->tph.hv1.tp_vlan_tpid
 #endif
     );
   return s;
@@ -193,23 +197,23 @@ af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
 			   vlib_frame_t * frame, af_packet_if_t * apif)
 {
   af_packet_main_t *apm = &af_packet_main;
-  struct tpacket2_hdr *tph;
+  tpacket3_hdr_t *tph;
   u32 next_index;
-  u32 block = 0;
-  u32 rx_frame;
   u32 n_free_bufs;
   u32 n_rx_packets = 0;
   u32 n_rx_bytes = 0;
   u32 *to_next = 0;
-  u32 block_size = apif->rx_req->tp_block_size;
-  u32 frame_size = apif->rx_req->tp_frame_size;
-  u32 frame_num = apif->rx_req->tp_frame_nr;
-  u8 *block_start = apif->rx_ring + block * block_size;
+  u32 block = apif->next_rx_block;
+  u32 block_nr = apif->rx_req->tp_block_nr;
+  u8 *block_start = 0;
   uword n_trace = vlib_get_trace_count (vm, node);
   u32 thread_index = vm->thread_index;
   u32 n_buffer_bytes = vlib_buffer_get_default_data_size (vm);
   u32 min_bufs = apif->rx_req->tp_frame_size / n_buffer_bytes;
   u32 eth_header_size = 0;
+  u32 num_pkts = 0;
+  u32 rx_frame_offset = 0;
+  block_desc_t *bd = 0;
   vlib_buffer_t bt;
 
   if (apif->mode == AF_PACKET_IF_MODE_IP)
@@ -227,170 +231,199 @@ af_packet_device_input_fn (vlib_main_t * vm, vlib_node_runtime_t * node,
       vnet_feature_start_device_input_x1 (apif->sw_if_index, &next_index, &bt);
     }
 
-  n_free_bufs = vec_len (apm->rx_buffers[thread_index]);
-  if (PREDICT_FALSE (n_free_bufs < VLIB_FRAME_SIZE))
+  while ((((block_desc_t *) (block_start = apif->rx_ring[block]))
+	    ->hdr.bh1.block_status &
+	  TP_STATUS_USER) != 0)
     {
-      vec_validate (apm->rx_buffers[thread_index],
-		    VLIB_FRAME_SIZE + n_free_bufs - 1);
-      n_free_bufs +=
-	vlib_buffer_alloc (vm, &apm->rx_buffers[thread_index][n_free_bufs],
-			   VLIB_FRAME_SIZE);
-      _vec_len (apm->rx_buffers[thread_index]) = n_free_bufs;
-    }
+      u32 n_required = 0;
 
-  rx_frame = apif->next_rx_frame;
-  tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
-  while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs))
-    {
-      vlib_buffer_t *b0 = 0, *first_b0 = 0;
-      u32 next0 = next_index;
+      if (PREDICT_FALSE (num_pkts == 0))
+	{
+	  bd = (block_desc_t *) block_start;
+	  num_pkts = bd->hdr.bh1.num_pkts;
+	  rx_frame_offset = sizeof (block_desc_t);
+	}
 
-      u32 n_left_to_next;
-      vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
-      while ((tph->tp_status & TP_STATUS_USER) && (n_free_bufs > min_bufs) &&
-	     n_left_to_next)
+      n_required = clib_max (num_pkts, VLIB_FRAME_SIZE);
+      n_free_bufs = vec_len (apm->rx_buffers[thread_index]);
+      if (PREDICT_FALSE (n_free_bufs < n_required))
 	{
-	  u32 data_len = tph->tp_snaplen;
-	  u32 offset = 0;
-	  u32 bi0 = 0, first_bi0 = 0, prev_bi0;
-	  u8 l4_hdr_sz = 0;
+	  vec_validate (apm->rx_buffers[thread_index],
+			n_required + n_free_bufs - 1);
+	  n_free_bufs += vlib_buffer_alloc (
+	    vm, &apm->rx_buffers[thread_index][n_free_bufs], n_required);
+	  _vec_len (apm->rx_buffers[thread_index]) = n_free_bufs;
+	}
 
-	  while (data_len)
+      while (num_pkts && (n_free_bufs > min_bufs))
+	{
+	  vlib_buffer_t *b0 = 0, *first_b0 = 0;
+	  u32 next0 = next_index;
+	  u32 n_left_to_next;
+	  vlib_get_next_frame (vm, node, next_index, to_next, n_left_to_next);
+	  while (num_pkts && n_left_to_next && (n_free_bufs > min_bufs))
 	    {
-	      /* grab free buffer */
-	      u32 last_empty_buffer =
-		vec_len (apm->rx_buffers[thread_index]) - 1;
-	      prev_bi0 = bi0;
-	      bi0 = apm->rx_buffers[thread_index][last_empty_buffer];
-	      b0 = vlib_get_buffer (vm, bi0);
-	      _vec_len (apm->rx_buffers[thread_index]) = last_empty_buffer;
-	      n_free_bufs--;
-
-	      /* copy data */
-	      u32 bytes_to_copy =
-		data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
-	      u32 vlan_len = 0;
-	      u32 bytes_copied = 0;
-	      b0->current_data = 0;
-	      /* Kernel removes VLAN headers, so reconstruct VLAN */
-	      if (PREDICT_FALSE (tph->tp_status & TP_STATUS_VLAN_VALID))
+	      tph = (tpacket3_hdr_t *) (block_start + rx_frame_offset);
+
+	      if (num_pkts > 1)
+		CLIB_PREFETCH (block_start + rx_frame_offset +
+				 tph->tp_next_offset,
+			       2 * CLIB_CACHE_LINE_BYTES, LOAD);
+	      u32 data_len = tph->tp_snaplen;
+	      u32 offset = 0;
+	      u32 bi0 = 0, first_bi0 = 0, prev_bi0;
+	      u8 l4_hdr_sz = 0;
+
+	      while (data_len)
 		{
-		  if (PREDICT_TRUE (offset == 0))
+		  /* grab free buffer */
+		  u32 last_empty_buffer =
+		    vec_len (apm->rx_buffers[thread_index]) - 1;
+		  prev_bi0 = bi0;
+		  bi0 = apm->rx_buffers[thread_index][last_empty_buffer];
+		  b0 = vlib_get_buffer (vm, bi0);
+		  _vec_len (apm->rx_buffers[thread_index]) = last_empty_buffer;
+		  n_free_bufs--;
+
+		  /* copy data */
+		  u32 bytes_to_copy =
+		    data_len > n_buffer_bytes ? n_buffer_bytes : data_len;
+		  u32 vlan_len = 0;
+		  u32 bytes_copied = 0;
+		  b0->current_data = 0;
+		  /* Kernel removes VLAN headers, so reconstruct VLAN */
+		  if (PREDICT_FALSE (tph->tp_status & TP_STATUS_VLAN_VALID))
 		    {
-		      clib_memcpy_fast (vlib_buffer_get_current (b0),
-					(u8 *) tph + tph->tp_mac,
-					sizeof (ethernet_header_t));
-		      ethernet_header_t *eth = vlib_buffer_get_current (b0);
-		      ethernet_vlan_header_t *vlan =
-			(ethernet_vlan_header_t *) (eth + 1);
-		      vlan->priority_cfi_and_id =
-			clib_host_to_net_u16 (tph->tp_vlan_tci);
-		      vlan->type = eth->type;
-		      eth->type = clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
-		      vlan_len = sizeof (ethernet_vlan_header_t);
-		      bytes_copied = sizeof (ethernet_header_t);
+		      if (PREDICT_TRUE (offset == 0))
+			{
+			  clib_memcpy_fast (vlib_buffer_get_current (b0),
+					    (u8 *) tph + tph->tp_mac,
+					    sizeof (ethernet_header_t));
+			  ethernet_header_t *eth =
+			    vlib_buffer_get_current (b0);
+			  ethernet_vlan_header_t *vlan =
+			    (ethernet_vlan_header_t *) (eth + 1);
+			  vlan->priority_cfi_and_id =
+			    clib_host_to_net_u16 (tph->hv1.tp_vlan_tci);
+			  vlan->type = eth->type;
+			  eth->type =
+			    clib_host_to_net_u16 (ETHERNET_TYPE_VLAN);
+			  vlan_len = sizeof (ethernet_vlan_header_t);
+			  bytes_copied = sizeof (ethernet_header_t);
+			}
 		    }
-		}
-	      clib_memcpy_fast (((u8 *) vlib_buffer_get_current (b0)) +
-				bytes_copied + vlan_len,
-				(u8 *) tph + tph->tp_mac + offset +
-				bytes_copied, (bytes_to_copy - bytes_copied));
+		  clib_memcpy_fast (((u8 *) vlib_buffer_get_current (b0)) +
+				      bytes_copied + vlan_len,
+				    (u8 *) tph + tph->tp_mac + offset +
+				      bytes_copied,
+				    (bytes_to_copy - bytes_copied));
+
+		  /* fill buffer header */
+		  b0->current_length = bytes_to_copy + vlan_len;
 
-	      /* fill buffer header */
-	      b0->current_length = bytes_to_copy + vlan_len;
+		  if (offset == 0)
+		    {
+		      b0->total_length_not_including_first_buffer = 0;
+		      b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
+		      vnet_buffer (b0)->sw_if_index[VLIB_RX] =
+			apif->sw_if_index;
+		      vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~0;
+		      first_bi0 = bi0;
+		      first_b0 = vlib_get_buffer (vm, first_bi0);
+		      if (tph->tp_status & TP_STATUS_CSUMNOTREADY)
+			mark_tcp_udp_cksum_calc (first_b0, &l4_hdr_sz);
+		      /* This is a trade-off for GSO. As kernel isn't passing
+		       * us the GSO state or size, we guess it by comparing it
+		       * to the host MTU of the interface */
+		      if (tph->tp_snaplen > (apif->host_mtu + eth_header_size))
+			fill_gso_buffer_flags (first_b0, apif->host_mtu,
+					       l4_hdr_sz);
+		    }
+		  else
+		    buffer_add_to_chain (vm, bi0, first_bi0, prev_bi0);
 
-	      if (offset == 0)
+		  offset += bytes_to_copy;
+		  data_len -= bytes_to_copy;
+		}
+	      n_rx_packets++;
+	      n_rx_bytes += tph->tp_snaplen;
+	      to_next[0] = first_bi0;
+	      to_next += 1;
+	      n_left_to_next--;
+
+	      /* drop partial packets */
+	      if (PREDICT_FALSE (tph->tp_len != tph->tp_snaplen))
 		{
-		  b0->total_length_not_including_first_buffer = 0;
-		  b0->flags = VLIB_BUFFER_TOTAL_LENGTH_VALID;
-		  vnet_buffer (b0)->sw_if_index[VLIB_RX] = apif->sw_if_index;
-		  vnet_buffer (b0)->sw_if_index[VLIB_TX] = (u32) ~ 0;
-		  first_bi0 = bi0;
-		  first_b0 = vlib_get_buffer (vm, first_bi0);
-		  if (tph->tp_status & TP_STATUS_CSUMNOTREADY)
-		    mark_tcp_udp_cksum_calc (first_b0, &l4_hdr_sz);
-		  /* This is a trade-off for GSO. As kernel isn't passing
-		   * us the GSO state or size, we guess it by comparing it
-		   * to the host MTU of the interface */
-		  if (tph->tp_snaplen > (apif->host_mtu + eth_header_size))
-		    fill_gso_buffer_flags (first_b0, apif->host_mtu,
-					   l4_hdr_sz);
+		  next0 = VNET_DEVICE_INPUT_NEXT_DROP;
+		  first_b0->error =
+		    node->errors[AF_PACKET_INPUT_ERROR_PARTIAL_PKT];
 		}
 	      else
-		buffer_add_to_chain (vm, bi0, first_bi0, prev_bi0);
-
-	      offset += bytes_to_copy;
-	      data_len -= bytes_to_copy;
-	    }
-	  n_rx_packets++;
-	  n_rx_bytes += tph->tp_snaplen;
-	  to_next[0] = first_bi0;
-	  to_next += 1;
-	  n_left_to_next--;
-
-	  /* drop partial packets */
-	  if (PREDICT_FALSE (tph->tp_len != tph->tp_snaplen))
-	    {
-	      next0 = VNET_DEVICE_INPUT_NEXT_DROP;
-	      first_b0->error =
-		node->errors[AF_PACKET_INPUT_ERROR_PARTIAL_PKT];
-	    }
-	  else
-	    {
-	      if (PREDICT_FALSE (apif->mode == AF_PACKET_IF_MODE_IP))
 		{
-		  switch (first_b0->data[0] & 0xf0)
+		  if (PREDICT_FALSE (apif->mode == AF_PACKET_IF_MODE_IP))
 		    {
-		    case 0x40:
-		      next0 = VNET_DEVICE_INPUT_NEXT_IP4_INPUT;
-		      break;
-		    case 0x60:
-		      next0 = VNET_DEVICE_INPUT_NEXT_IP6_INPUT;
-		      break;
-		    default:
-		      next0 = VNET_DEVICE_INPUT_NEXT_DROP;
-		      break;
+		      switch (first_b0->data[0] & 0xf0)
+			{
+			case 0x40:
+			  next0 = VNET_DEVICE_INPUT_NEXT_IP4_INPUT;
+			  break;
+			case 0x60:
+			  next0 = VNET_DEVICE_INPUT_NEXT_IP6_INPUT;
+			  break;
+			default:
+			  next0 = VNET_DEVICE_INPUT_NEXT_DROP;
+			  break;
+			}
+		      if (PREDICT_FALSE (apif->per_interface_next_index != ~0))
+			next0 = apif->per_interface_next_index;
+		    }
+		  else
+		    {
+		      /* copy feature arc data from template */
+		      first_b0->current_config_index = bt.current_config_index;
+		      vnet_buffer (first_b0)->feature_arc_index =
+			vnet_buffer (&bt)->feature_arc_index;
 		    }
-		  if (PREDICT_FALSE (apif->per_interface_next_index != ~0))
-		    next0 = apif->per_interface_next_index;
 		}
-	      else
+
+	      /* trace */
+	      if (PREDICT_FALSE (n_trace > 0 &&
+				 vlib_trace_buffer (vm, node, next0, first_b0,
+						    /* follow_chain */ 0)))
 		{
-		  /* copy feature arc data from template */
-		  first_b0->current_config_index = bt.current_config_index;
-		  vnet_buffer (first_b0)->feature_arc_index =
-		    vnet_buffer (&bt)->feature_arc_index;
+		  af_packet_input_trace_t *tr;
+		  vlib_set_trace_count (vm, node, --n_trace);
+		  tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
+		  tr->next_index = next0;
+		  tr->hw_if_index = apif->hw_if_index;
+		  tr->block = block;
+		  tr->block_start = bd;
+		  tr->num_pkts = num_pkts;
+		  clib_memcpy_fast (&tr->bd, bd, sizeof (block_desc_t));
+		  clib_memcpy_fast (&tr->tph, tph, sizeof (tpacket3_hdr_t));
 		}
-	    }
 
-	  /* trace */
-	  if (PREDICT_FALSE
-	      (n_trace > 0 && vlib_trace_buffer (vm, node, next0, first_b0,
-						 /* follow_chain */ 0)))
-	    {
-	      af_packet_input_trace_t *tr;
-	      vlib_set_trace_count (vm, node, --n_trace);
-	      tr = vlib_add_trace (vm, node, first_b0, sizeof (*tr));
-	      tr->next_index = next0;
-	      tr->hw_if_index = apif->hw_if_index;
-	      clib_memcpy_fast (&tr->tph, tph, sizeof (struct tpacket2_hdr));
-	    }
+	      /* enque and take next packet */
+	      vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
+					       n_left_to_next, first_bi0,
+					       next0);
 
-	  /* enque and take next packet */
-	  vlib_validate_buffer_enqueue_x1 (vm, node, next_index, to_next,
-					   n_left_to_next, first_bi0, next0);
+	      /* next packet */
+	      num_pkts--;
+	      rx_frame_offset += tph->tp_next_offset;
+	    }
 
-	  /* next packet */
-	  tph->tp_status = TP_STATUS_KERNEL;
-	  rx_frame = (rx_frame + 1) % frame_num;
-	  tph = (struct tpacket2_hdr *) (block_start + rx_frame * frame_size);
+	  vlib_put_next_frame (vm, node, next_index, n_left_to_next);
 	}
 
-      vlib_put_next_frame (vm, node, next_index, n_left_to_next);
+      if (PREDICT_TRUE (num_pkts == 0))
+	{
+	  bd->hdr.bh1.block_status = TP_STATUS_KERNEL;
+	  block = (block + 1) % block_nr;
+	}
     }
 
-  apif->next_rx_frame = rx_frame;
-
+  apif->next_rx_block = block;
   vlib_increment_combined_counter
     (vnet_get_main ()->interface_main.combined_sw_if_counters
      + VNET_INTERFACE_COUNTER_RX,