dpdk: cleanup MTU handling

Type: improvement
Change-Id: I4b929693f3671be8ee63a58afcbac75a27d99d57
Signed-off-by: Damjan Marion <damarion@cisco.com>

3 files changed, 31 insertions, 99 deletions

diff --git a/src/plugins/dpdk/device/common.c b/src/plugins/dpdk/device/common.c
index f77e377e14c..c32382a55c6 100644
--- a/src/plugins/dpdk/device/common.c
+++ b/src/plugins/dpdk/device/common.c
@@ -48,6 +48,7 @@ dpdk_device_setup (dpdk_device_t * xd)
   vnet_hw_interface_t *hi = vnet_get_hw_interface (vnm, xd->hw_if_index);
   struct rte_eth_dev_info dev_info;
   u64 bitmap;
+  u16 mtu;
   int rv;
   int j;
 
@@ -89,6 +90,12 @@ dpdk_device_setup (dpdk_device_t * xd)
       xd->port_conf.rxmode.offloads ^= bitmap;
     }
 
+  if (xd->port_conf.rxmode.offloads & DEV_RX_OFFLOAD_JUMBO_FRAME)
+    xd->port_conf.rxmode.max_rx_pkt_len =
+      clib_min (ETHERNET_MAX_PACKET_BYTES, dev_info.max_rx_pktlen);
+  else
+    xd->port_conf.rxmode.max_rx_pkt_len = 0;
+
   rv = rte_eth_dev_configure (xd->port_id, xd->conf.n_rx_queues,
 			      xd->conf.n_tx_queues, &xd->port_conf);
 
@@ -98,6 +105,21 @@ dpdk_device_setup (dpdk_device_t * xd)
       goto error;
     }
 
+  rte_eth_dev_get_mtu (xd->port_id, &mtu);
+  dpdk_log_debug ("[%u] device default mtu %u", xd->port_id, mtu);
+
+  hi->max_supported_packet_bytes = mtu;
+  if (hi->max_packet_bytes > mtu)
+    {
+      vnet_hw_interface_set_mtu (vnm, xd->hw_if_index, mtu);
+    }
+  else
+    {
+      rte_eth_dev_set_mtu (xd->port_id, hi->max_packet_bytes);
+      dpdk_log_debug ("[%u] port mtu set to %u", xd->port_id,
+		      hi->max_packet_bytes);
+    }
+
   vec_validate_aligned (xd->tx_queues, xd->conf.n_tx_queues - 1,
 			CLIB_CACHE_LINE_BYTES);
   for (j = 0; j < xd->conf.n_tx_queues; j++)
@@ -144,7 +166,6 @@ dpdk_device_setup (dpdk_device_t * xd)
   if (vec_len (xd->errors))
     goto error;
 
-  rte_eth_dev_set_mtu (xd->port_id, hi->max_packet_bytes);
   xd->buffer_flags =
     (VLIB_BUFFER_TOTAL_LENGTH_VALID | VLIB_BUFFER_EXT_HDR_VALID);
 
diff --git a/src/plugins/dpdk/device/dpdk.h b/src/plugins/dpdk/device/dpdk.h
index 3026734c39f..ff2bf6f9c50 100644
--- a/src/plugins/dpdk/device/dpdk.h
+++ b/src/plugins/dpdk/device/dpdk.h
@@ -420,6 +420,8 @@ typedef enum
   vlib_log(VLIB_LOG_LEVEL_NOTICE, dpdk_main.log_default, __VA_ARGS__)
 #define dpdk_log_info(...) \
   vlib_log(VLIB_LOG_LEVEL_INFO, dpdk_main.log_default, __VA_ARGS__)
+#define dpdk_log_debug(...)                                                   \
+  vlib_log (VLIB_LOG_LEVEL_DEBUG, dpdk_main.log_default, __VA_ARGS__)
 
 void dpdk_update_link_state (dpdk_device_t * xd, f64 now);
 
diff --git a/src/plugins/dpdk/device/init.c b/src/plugins/dpdk/device/init.c
index 1ee03323d61..fd1c9115954 100644
--- a/src/plugins/dpdk/device/init.c
+++ b/src/plugins/dpdk/device/init.c
@@ -97,8 +97,13 @@ dpdk_flag_change (vnet_main_t * vnm, vnet_hw_interface_t * hi, u32 flags)
       xd->flags |= DPDK_DEVICE_FLAG_PROMISC;
       break;
     case ETHERNET_INTERFACE_FLAG_MTU:
-      xd->port_conf.rxmode.max_rx_pkt_len = hi->max_packet_bytes;
-      dpdk_device_setup (xd);
+      if (xd->flags & DPDK_DEVICE_FLAG_ADMIN_UP)
+	rte_eth_dev_stop (xd->port_id);
+      rte_eth_dev_set_mtu (xd->port_id, hi->max_packet_bytes);
+      if (xd->flags & DPDK_DEVICE_FLAG_ADMIN_UP)
+	rte_eth_dev_start (xd->port_id);
+      dpdk_log_debug ("[%u] mtu changed to %u", xd->port_id,
+		      hi->max_packet_bytes);
       return 0;
     default:
       return ~0;
@@ -115,12 +120,6 @@ dpdk_flag_change (vnet_main_t * vnm, vnet_hw_interface_t * hi, u32 flags)
   return old;
 }
 
-static int
-dpdk_port_crc_strip_enabled (dpdk_device_t * xd)
-{
-  return !(xd->port_conf.rxmode.offloads & DEV_RX_OFFLOAD_KEEP_CRC);
-}
-
 /* The function check_l3cache helps check if Level 3 cache exists or not on current CPUs
   return value 1: exist.
   return value 0: not exist.
@@ -176,7 +175,6 @@ dpdk_lib_init (dpdk_main_t * dm)
 {
   vnet_main_t *vnm = vnet_get_main ();
   u32 nports;
-  u32 mtu, max_rx_frame;
   u16 port_id;
   clib_error_t *error;
   vlib_main_t *vm = vlib_get_main ();
@@ -652,80 +650,6 @@ dpdk_lib_init (dpdk_main_t * dm)
       if (error)
 	return error;
 
-      /*
-       * Ensure default mtu is not > the mtu read from the hardware.
-       * Otherwise rte_eth_dev_configure() will fail and the port will
-       * not be available.
-       * Calculate max_frame_size and mtu supported by NIC
-       */
-      if (ETHERNET_MAX_PACKET_BYTES > di.max_rx_pktlen)
-	{
-	  /*
-	   * This device does not support the platforms's max frame
-	   * size. Use it's advertised mru instead.
-	   */
-	  max_rx_frame = di.max_rx_pktlen;
-	  mtu = di.max_rx_pktlen - sizeof (ethernet_header_t);
-	}
-      else
-	{
-	  /* VPP treats MTU and max_rx_pktlen both equal to
-	   * ETHERNET_MAX_PACKET_BYTES, if dev_info.max_rx_pktlen >=
-	   * ETHERNET_MAX_PACKET_BYTES + sizeof(ethernet_header_t)
-	   */
-	  if (di.max_rx_pktlen >=
-	      (ETHERNET_MAX_PACKET_BYTES + sizeof (ethernet_header_t)))
-	    {
-	      mtu = ETHERNET_MAX_PACKET_BYTES;
-	      max_rx_frame = ETHERNET_MAX_PACKET_BYTES;
-
-	      /*
-	       * Some platforms do not account for Ethernet FCS (4 bytes) in
-	       * MTU calculations. To interop with them increase mru but only
-	       * if the device's settings can support it.
-	       */
-	      if (dpdk_port_crc_strip_enabled (xd) &&
-		  (di.max_rx_pktlen >= (ETHERNET_MAX_PACKET_BYTES +
-					sizeof (ethernet_header_t) + 4)))
-		{
-		  max_rx_frame += 4;
-		}
-	    }
-	  else
-	    {
-	      max_rx_frame = ETHERNET_MAX_PACKET_BYTES;
-	      mtu = ETHERNET_MAX_PACKET_BYTES - sizeof (ethernet_header_t);
-
-	      if (dpdk_port_crc_strip_enabled (xd) &&
-		  (di.max_rx_pktlen >= (ETHERNET_MAX_PACKET_BYTES + 4)))
-		{
-		  max_rx_frame += 4;
-		}
-	    }
-	}
-
-      if (xd->pmd == VNET_DPDK_PMD_FAILSAFE)
-	{
-	  /* failsafe device numerables are reported with active device only,
-	   * need to query the mtu for current device setup to overwrite
-	   * reported value.
-	   */
-	  uint16_t dev_mtu;
-	  if (!rte_eth_dev_get_mtu (port_id, &dev_mtu))
-	    {
-	      mtu = dev_mtu;
-	      max_rx_frame = mtu + sizeof (ethernet_header_t);
-
-	      if (dpdk_port_crc_strip_enabled (xd))
-		{
-		  max_rx_frame += 4;
-		}
-	    }
-	}
-
-      /*Set port rxmode config */
-      xd->port_conf.rxmode.max_rx_pkt_len = max_rx_frame;
-
       sw = vnet_get_hw_sw_interface (vnm, xd->hw_if_index);
       xd->sw_if_index = sw->sw_if_index;
       vnet_hw_if_set_input_node (vnm, xd->hw_if_index, dpdk_input_node.index);
@@ -754,12 +678,8 @@ dpdk_lib_init (dpdk_main_t * dm)
       /*Get vnet hardware interface */
       hi = vnet_get_hw_interface (vnm, xd->hw_if_index);
 
-      /*Override default max_packet_bytes and max_supported_bytes set in
-       * ethernet_register_interface() above*/
       if (hi)
 	{
-	  hi->max_packet_bytes = mtu;
-	  hi->max_supported_packet_bytes = max_rx_frame;
 	  hi->numa_node = xd->cpu_socket;
 
 	  /* Indicate ability to support L3 DMAC filtering and
@@ -819,17 +739,6 @@ dpdk_lib_init (dpdk_main_t * dm)
 	dpdk_log_err ("setup failed for device %U. Errors:\n  %U",
 		      format_dpdk_device_name, port_id,
 		      format_dpdk_device_errors, xd);
-
-      if (hi)
-	hi->max_packet_bytes =
-	  xd->port_conf.rxmode.max_rx_pkt_len - sizeof (ethernet_header_t);
-      else
-	dpdk_log_warn ("hi NULL");
-
-      if (xd->conf.no_multi_seg)
-	mtu = mtu > ETHER_MAX_LEN ? ETHER_MAX_LEN : mtu;
-
-      rte_eth_dev_set_mtu (xd->port_id, mtu);
     }
 
   return 0;