[Core] Use individual MM items in P0/P1 cache and model runner (#22570)

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

vllm/v1/engine/core.py

@@ -409,12 +409,13 @@ class EngineCore:
         request initialization running in parallel with Model forward
         """
         if request.mm_hashes is not None:
-            assert request.mm_inputs is not None
+            assert request.mm_kwargs is not None
+
             # Note on thread safety: no race condition.
             # `mm_input_cache_server` is reset at the end of LLMEngine init,
             # and will only accessed in the input processing thread afterwards.
-            request.mm_inputs = self.mm_input_cache_server.get_and_update(
-                request.mm_inputs, request.mm_hashes)
+            request.mm_kwargs = self.mm_input_cache_server.get_and_update(
+                request.mm_kwargs, request.mm_hashes)
 
         req = Request.from_engine_core_request(request)
         if req.use_structured_output: