[Bugfix] qwen3-vl-235b-w8a8 load weight ERROR when start service (#4292)

### What this PR does / why we need it?
fix qwen3-vl-w8a8 load weight ERROR when start service
0.12.0rc1 can start qwen3-vl-235b-w8a8 by adding this PR

- vLLM version: v0.11.0
- vLLM main:
2918c1b49c

---------

Signed-off-by: Levi-JQ <yujinqi2@huawei.com>
Co-authored-by: Levi-JQ <yujinqi2@huawei.com>

vllm_ascend/quantization/quant_config.py

@@ -32,6 +32,7 @@ from vllm.model_executor.layers.quantization.base_config import (
 from vllm.model_executor.layers.quantization.kv_cache import BaseKVCacheMethod
 from vllm.model_executor.layers.vocab_parallel_embedding import (
     UnquantizedEmbeddingMethod, VocabParallelEmbedding)
+from vllm.model_executor.models.utils import WeightsMapper
 from vllm.model_executor.parameter import PerTensorScaleParameter
 from vllm.model_executor.utils import set_weight_attrs
 
@@ -103,6 +104,15 @@ class AscendQuantConfig(QuantizationConfig):
                 return ASCEND_QUANTIZATION_METHOD
         return None
 
+    def quant_prefix_mapper(self, model_type: str, prefix: str) -> str:
+        # TODO (Levi-JQ): will be removed when QuantizationConfig.apply_vllm_mapper is implemented
+        prefix_mapping = QUANT_MODEL_PREFIX_MAPPINGS.get(model_type)
+        if prefix_mapping:
+            hf_to_vllm_mapper = WeightsMapper(
+                orig_to_new_prefix=prefix_mapping)
+            return hf_to_vllm_mapper._map_name(prefix)
+        return prefix
+
     def get_quant_method(self, layer: torch.nn.Module,
                          prefix: str) -> Optional["QuantizeMethodBase"]:
         vllm_config = get_current_vllm_config()
@@ -110,6 +120,7 @@ class AscendQuantConfig(QuantizationConfig):
         if model_type in packed_modules_model_mapping:
             self.packed_modules_mapping = packed_modules_model_mapping[
                 model_type]
+        prefix = self.quant_prefix_mapper(model_type, prefix)
         from vllm.attention.layer import Attention
         if prefix.startswith("language_model"):
             prefix = prefix.split('.', 1)[-1]
@@ -174,6 +185,16 @@ class AscendQuantConfig(QuantizationConfig):
         return []
 
 
+# key: model_type
+# value: orig_to_new_prefix
+QUANT_MODEL_PREFIX_MAPPINGS = {
+    "qwen3_vl_moe": {
+        "visual.": "model.visual.",
+        "language_model.lm_head.": "lm_head.",
+        "language_model.model.": "model.language_model.",
+    },
+}
+
 packed_modules_model_mapping = {
     "qwen3_moe": {
         "qkv_proj": [
@@ -242,6 +263,19 @@ packed_modules_model_mapping = {
             "up_proj",
         ],
     },
+    "qwen3_vl_moe": {
+        "qkv_proj": [
+            "q_proj",
+            "k_proj",
+            "v_proj",
+        ],
+        "gate_up_proj": [
+            "gate_proj",
+            "up_proj",
+        ],
+        "experts":
+        ["experts.0.gate_proj", "experts.0.up_proj", "experts.0.down_proj"],
+    },
     "glm4_moe": {
         "qkv_proj": [
             "q_proj",