datapath-windows: Updating an External Adapter causes flow lookup fai…

…lure

This patch fixes an issue with updating the propeties of an external
adapter in Windows. The issue causes flow lookups to fail until the
kernel is reinstalled.

Reported-at: openvswitch/ovs-issues#102
Signed-off-by: Sairam Venugopal <vsairam@vmware.com>
Acked-by: Nithin Raju <nithin@vmware.com>
Signed-off-by: Ben Pfaff <blp@nicira.com>

datapath-windows/ovsext/Vport.c

@@ -322,19 +322,51 @@ HvCreateNic(POVS_SWITCH_CONTEXT switchContext,
         POVS_VPORT_ENTRY virtExtVport =
             (POVS_VPORT_ENTRY)switchContext->virtualExternalVport;
 
-        vport = (POVS_VPORT_ENTRY)OvsAllocateVport();
+        vport = OvsFindVportByPortIdAndNicIndex(switchContext,
+                                                nicParam->PortId,
+                                                nicParam->NicIndex);
         if (vport == NULL) {
-            status = NDIS_STATUS_RESOURCES;
-            goto add_nic_done;
+            /* Find by interface name */
+            WCHAR interfaceName[IF_MAX_STRING_SIZE] = { 0 };
+            NET_LUID interfaceLuid = { 0 };
+            size_t len = 0;
+            status = ConvertInterfaceGuidToLuid(&nicParam->NetCfgInstanceId,
+                                                &interfaceLuid);
+            if (status == STATUS_SUCCESS) {
+                status = ConvertInterfaceLuidToAlias(&interfaceLuid,
+                                                     interfaceName,
+                                                     IF_MAX_STRING_SIZE + 1);
+                if (status == STATUS_SUCCESS) {
+                    RtlStringCbLengthW(interfaceName,
+                                       IF_MAX_STRING_SIZE,
+                                       &len);
+                    vport = OvsFindVportByHvNameW(switchContext,
+                                                  interfaceName,
+                                                  len);
+                }
+            }
+
+            if (vport == NULL) {
+                /* XXX: Handle this event appropriately */
+                vport = (POVS_VPORT_ENTRY)OvsAllocateVport();
+                if (vport == NULL) {
+                    status = NDIS_STATUS_RESOURCES;
+                    goto add_nic_done;
+                }
+            }
         }
+
         OvsInitPhysNicVport(vport, virtExtVport, nicParam->NicIndex);
+        OvsInitVportWithNicParam(switchContext, vport, nicParam);
         status = InitHvVportCommon(switchContext, vport, TRUE);
+        vport->isAbsentOnHv = FALSE;
         if (status != NDIS_STATUS_SUCCESS) {
             OvsFreeMemoryWithTag(vport, OVS_VPORT_POOL_TAG);
             goto add_nic_done;
         }
+    } else {
+        OvsInitVportWithNicParam(switchContext, vport, nicParam);
     }
-    OvsInitVportWithNicParam(switchContext, vport, nicParam);
     portNo = vport->portNo;
     if (vport->ovsState == OVS_STATE_CONNECTED) {
         event = OVS_EVENT_CONNECT | OVS_EVENT_LINK_UP;