interface: improve MTU handling

 - per hw-interface-class handlers
 - ethernet set_mtu callback
 - driver can now refuse MTU change

Type: improvement
Change-Id: I3d37c9129930ebec7bb70caf4263025413873048
Signed-off-by: Damjan Marion <damarion@cisco.com>

3 files changed, 51 insertions, 18 deletions

diff --git a/src/plugins/af_xdp/device.c b/src/plugins/af_xdp/device.c
index 4aa36d95dd5..a5e0b739300 100644
--- a/src/plugins/af_xdp/device.c
+++ b/src/plugins/af_xdp/device.c
@@ -67,6 +67,15 @@ af_xdp_mac_change (vnet_hw_interface_t * hw, const u8 * old, const u8 * new)
   return 0;
 }
 
+static clib_error_t *
+af_xdp_set_mtu (vnet_main_t *vnm, vnet_hw_interface_t *hw, u32 mtu)
+{
+  af_xdp_main_t *am = &af_xdp_main;
+  af_xdp_device_t *ad = vec_elt_at_index (am->devices, hw->dev_instance);
+  af_xdp_log (VLIB_LOG_LEVEL_ERR, ad, "set mtu not supported yet");
+  return vnet_error (VNET_ERR_UNSUPPORTED, 0);
+}
+
 static u32
 af_xdp_flag_change (vnet_main_t * vnm, vnet_hw_interface_t * hw, u32 flags)
 {
@@ -82,9 +91,6 @@ af_xdp_flag_change (vnet_main_t * vnm, vnet_hw_interface_t * hw, u32 flags)
       af_xdp_log (VLIB_LOG_LEVEL_ERR, ad,
 		  "set promiscuous not supported yet");
       return ~0;
-    case ETHERNET_INTERFACE_FLAG_MTU:
-      af_xdp_log (VLIB_LOG_LEVEL_ERR, ad, "set mtu not supported yet");
-      return ~0;
     }
 
   af_xdp_log (VLIB_LOG_LEVEL_ERR, ad, "unknown flag %x requested", flags);
@@ -651,6 +657,7 @@ af_xdp_create_if (vlib_main_t * vm, af_xdp_create_if_args_t * args)
   eir.dev_instance = ad->dev_instance;
   eir.address = ad->hwaddr;
   eir.cb.flag_change = af_xdp_flag_change;
+  eir.cb.set_mtu = af_xdp_set_mtu;
   ad->hw_if_index = vnet_eth_register_interface (vnm, &eir);
 
   sw = vnet_get_hw_sw_interface (vnm, ad->hw_if_index);
diff --git a/src/plugins/dpdk/device/init.c b/src/plugins/dpdk/device/init.c
index 5e06e48d37e..4faf6290dba 100644
--- a/src/plugins/dpdk/device/init.c
+++ b/src/plugins/dpdk/device/init.c
@@ -21,6 +21,7 @@
 #include <vlib/unix/unix.h>
 #include <vlib/log.h>
 
+#include <vnet/vnet.h>
 #include <vnet/ethernet/ethernet.h>
 #include <vnet/interface/rx_queue_funcs.h>
 #include <dpdk/buffer.h>
@@ -68,6 +69,41 @@ const struct
   { ETH_LINK_SPEED_1G, "GigabitEthernet" },
 };
 
+static clib_error_t *
+dpdk_set_mtu (vnet_main_t *vnm, vnet_hw_interface_t *hi, u32 mtu)
+{
+  dpdk_main_t *dm = &dpdk_main;
+  dpdk_device_t *xd = vec_elt_at_index (dm->devices, hi->dev_instance);
+  int rv;
+
+  rv = rte_eth_dev_set_mtu (xd->port_id, mtu);
+
+  if (rv < 0)
+    {
+      dpdk_log_err ("[%u] rte_eth_dev_set_mtu failed (mtu %u, rv %d)",
+		    xd->port_id, mtu, rv);
+      switch (rv)
+	{
+	case -ENOTSUP:
+	  return vnet_error (VNET_ERR_UNSUPPORTED,
+			     "dpdk driver doesn't support MTU change");
+	case -EBUSY:
+	  return vnet_error (VNET_ERR_BUSY, "port is running");
+	case -EINVAL:
+	  return vnet_error (VNET_ERR_INVALID_VALUE, "invalid MTU");
+	default:
+	  return vnet_error (VNET_ERR_BUG,
+			     "unexpected return value %d returned from "
+			     "rte_eth_dev_set_mtu(...)",
+			     rv);
+	}
+    }
+  else
+    dpdk_log_debug ("[%u] mtu set to %u", xd->port_id, mtu);
+
+  return 0;
+}
+
 static u32
 dpdk_flag_change (vnet_main_t * vnm, vnet_hw_interface_t * hi, u32 flags)
 {
@@ -84,15 +120,6 @@ dpdk_flag_change (vnet_main_t * vnm, vnet_hw_interface_t * hi, u32 flags)
     case ETHERNET_INTERFACE_FLAG_ACCEPT_ALL:
       dpdk_device_flag_set (xd, DPDK_DEVICE_FLAG_PROMISC, 1);
       break;
-    case ETHERNET_INTERFACE_FLAG_MTU:
-      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;
     }
@@ -370,6 +397,7 @@ dpdk_lib_init (dpdk_main_t * dm)
       eir.dev_instance = xd->device_index;
       eir.address = addr;
       eir.cb.flag_change = dpdk_flag_change;
+      eir.cb.set_mtu = dpdk_set_mtu;
       xd->hw_if_index = vnet_eth_register_interface (vnm, &eir);
       hi = vnet_get_hw_interface (vnm, xd->hw_if_index);
       hi->numa_node = xd->cpu_socket = (i8) rte_eth_dev_socket_id (port_id);
diff --git a/src/plugins/rdma/device.c b/src/plugins/rdma/device.c
index cad5fdb541f..167a23213cc 100644
--- a/src/plugins/rdma/device.c
+++ b/src/plugins/rdma/device.c
@@ -183,11 +183,10 @@ rdma_mac_change (vnet_hw_interface_t * hw, const u8 * old, const u8 * new)
   return 0;
 }
 
-static u32
-rdma_dev_change_mtu (rdma_device_t * rd)
+static clib_error_t *
+rdma_set_mtu (vnet_main_t *vnm, vnet_hw_interface_t *hw, u32 mtu)
 {
-  rdma_log__ (VLIB_LOG_LEVEL_ERR, rd, "MTU change not supported");
-  return ~0;
+  return vnet_error (VNET_ERR_UNSUPPORTED, 0);
 }
 
 static u32
@@ -202,8 +201,6 @@ rdma_flag_change (vnet_main_t * vnm, vnet_hw_interface_t * hw, u32 flags)
       return rdma_dev_set_ucast (rd);
     case ETHERNET_INTERFACE_FLAG_ACCEPT_ALL:
       return rdma_dev_set_promisc (rd);
-    case ETHERNET_INTERFACE_FLAG_MTU:
-      return rdma_dev_change_mtu (rd);
     }
 
   rdma_log__ (VLIB_LOG_LEVEL_ERR, rd, "unknown flag %x requested", flags);
@@ -361,6 +358,7 @@ rdma_register_interface (vnet_main_t * vnm, rdma_device_t * rd)
   eir.dev_instance = rd->dev_instance;
   eir.address = rd->hwaddr.bytes;
   eir.cb.flag_change = rdma_flag_change;
+  eir.cb.set_mtu = rdma_set_mtu;
   rd->hw_if_index = vnet_eth_register_interface (vnm, &eir);
   /* Indicate ability to support L3 DMAC filtering and
    * initialize interface to L3 non-promisc mode */