[V1] Refactor model executable interface for multimodal models (#10570)

Signed-off-by: Roger Wang <ywang@roblox.com>

vllm/model_executor/models/llava.py

@@ -478,7 +478,7 @@ class LlavaForConditionalGeneration(nn.Module, SupportsMultiModal, SupportsPP):
         image_features = self._process_image_pixels(image_input)
         return self.multi_modal_projector(image_features)
 
-    def process_mm_inputs(self, **kwargs):
+    def get_multimodal_embeddings(self, **kwargs) -> Optional[NestedTensors]:
         image_input = self._parse_and_validate_image_input(**kwargs)
         if image_input is None:
             return None
@@ -488,12 +488,12 @@ class LlavaForConditionalGeneration(nn.Module, SupportsMultiModal, SupportsPP):
     def get_input_embeddings(
         self,
         input_ids: torch.Tensor,
-        vision_embeddings: Optional[NestedTensors] = None,
+        multimodal_embeddings: Optional[NestedTensors] = None,
     ) -> torch.Tensor:
         inputs_embeds = self.language_model.get_input_embeddings(input_ids)
-        if vision_embeddings is not None:
+        if multimodal_embeddings is not None:
             inputs_embeds = merge_multimodal_embeddings(
-                input_ids, inputs_embeds, vision_embeddings,
+                input_ids, inputs_embeds, multimodal_embeddings,
                 self.config.image_token_index)
         return inputs_embeds
 
@@ -544,10 +544,11 @@ class LlavaForConditionalGeneration(nn.Module, SupportsMultiModal, SupportsPP):
         """
         if intermediate_tensors is not None:
             inputs_embeds = None
+
+        # NOTE: In v1, inputs_embeds is always generated at model runner, this
+        # condition is for v0 compatibility.
         elif inputs_embeds is None:
-            vision_embeddings = self.process_mm_inputs(**kwargs)
-            # always pass the input via `inputs_embeds`
-            # to make sure the computation graph is consistent
+            vision_embeddings = self.get_multimodal_embeddings(**kwargs)
             inputs_embeds = self.get_input_embeddings(input_ids,
                                                       vision_embeddings)
             input_ids = None