[5/N] Initialize MM components in context managers (Q-Z) (#32695)

Signed-off-by: DarkLight1337 <tlleungac@connect.ust.hk>

vllm/model_executor/models/qwen3_vl.py

@@ -1321,7 +1321,13 @@ class Qwen3VLForConditionalGeneration(
         num_layers = len(self.language_model.model.layers)
         return (2, num_layers // 2, num_layers - 3)
 
-    def _get_deepstack_input_embeds(self, num_tokens: int) -> IntermediateTensors:
+    def _get_deepstack_input_embeds(
+        self,
+        num_tokens: int,
+    ) -> IntermediateTensors | None:
+        if not getattr(self, "deepstack_input_embeds", None):
+            return None  # If vision tower is skipped
+
         # get deepstack_input_embeds from buffer, and clear the buffer
         return IntermediateTensors(
             {
@@ -1333,6 +1339,9 @@ class Qwen3VLForConditionalGeneration(
         )
 
     def _set_deepstack_input_embeds(self, deepstack_input_embeds: torch.Tensor) -> None:
+        if not getattr(self, "deepstack_input_embeds", None):
+            return
+
         # set deepstack_input_embeds to buffer
         num_tokens = deepstack_input_embeds.size(1)
         if num_tokens > self.deepstack_input_embeds[0].size(0):
@@ -1351,6 +1360,9 @@ class Qwen3VLForConditionalGeneration(
             )
 
     def _clear_deepstack_input_embeds(self, num_tokens: int) -> None:
+        if not getattr(self, "deepstack_input_embeds", None):
+            return
+
         # clear deepstack_input_embeds in buffer
         if num_tokens > 0:
             for idx in range(self.deepstack_num_level):
@@ -2037,11 +2049,7 @@ class Qwen3VLForConditionalGeneration(
         if intermediate_tensors is not None:
             inputs_embeds = None
 
-        if (
-            self.use_deepstack
-            and inputs_embeds is not None
-            and get_pp_group().is_first_rank
-        ):
+        if inputs_embeds is not None and get_pp_group().is_first_rank:
             deepstack_input_embeds = self._get_deepstack_input_embeds(
                 inputs_embeds.size(0)
             )