!307 Add device_target check for DP Train

Merge pull request !307 from jxlang910/master

mindarmour/privacy/diff_privacy/train/model.py

@@ -159,6 +159,13 @@ class DPModel(Model):
             self._clip_mech = clip_mech
         super(DPModel, self).__init__(**kwargs)
 
+        # judge device_target, only GPU or Ascend is supported until now
+        device = context.get_context("device_target")
+        if device not in ["GPU", "Ascend"]:
+            msg = "'device_target' or DP training should be 'GPU' or 'Ascend', but got {}.".format(device)
+            LOGGER.error(TAG, msg)
+            raise ValueError(msg)
+
     def _amp_build_train_network(self, network, optimizer, loss_fn=None,
                                  level='O0', **kwargs):
         """