CA-88840:User Friendly error message when cross/intrapool migration fails

Signed-off-by: Akshay Ramani <[email protected]>

Author: akshayramani

ocaml/idl/api_errors.ml

@@ -462,3 +462,4 @@ let vm_has_checkpoint = "VM_HAS_CHECKPOINT"
 
 let mirror_failed = "MIRROR_FAILED"
 let too_many_storage_migrates = "TOO_MANY_STORAGE_MIGRATES"
+let unimplemented_in_sm_backend = "UNIMPLEMENTED_IN_SM_BACKEND"

ocaml/idl/datamodel.ml

@@ -410,7 +410,8 @@ let _ =
     ~doc:"You attempted an operation that was explicitly blocked (see the blocked_operations field of the given object)." ();
   error Api_errors.not_implemented ["function"] 
     ~doc:"The function is not implemented" ();
-
+  error Api_errors.unimplemented_in_sm_backend ["message"]
+		~doc:"You have attempted a function which is not implemented" ();
   (* DB errors *)
   error Api_errors.handle_invalid ["class"; "handle"]
     ~doc:"You gave an invalid object reference.  The object may have recently been deleted.  The class parameter gives the type of reference given, and the handle parameter echoes the bad value given." ();

ocaml/xapi/storage_migrate.ml

@@ -651,7 +651,8 @@ let wrap ~dbg f =
 			| Backend_error(code, params)
 			| Api_errors.Server_error(code, params) ->
 				raise (Backend_error(code, params))
-			| e ->
+			| Unimplemented msg -> raise (Unimplemented msg) 
+			| e -> 
 				raise (Internal_error(Printexc.to_string e))) in
 	let _ = Thread.create 
 		(Debug.with_thread_associated dbg (fun () ->

ocaml/xapi/xapi_vm_migrate.ml

@@ -536,6 +536,7 @@ let migrate_send'  ~__context ~vm ~dest ~live ~vdi_map ~vif_map ~options =
 				TaskHelper.exn_if_cancelling ~__context;
 				begin match e with
 					| Storage_interface.Backend_error(code, params) -> raise (Api_errors.Server_error(code, params))
+					| Storage_interface.Unimplemented(code) -> raise (Api_errors.Server_error(Api_errors.unimplemented_in_sm_backend, [code]))
 					| _ -> raise e
 				end