cleanup ascend config (#5296)

1. refresh additional config doc
2. move kv config logic to platform.
3. improve `dump_config` init logic and rename it to `dump_config_path`
this change is user impacted. dump_config is changed from dict to
string.
4. correct `enable_async_exponential` type
5. remove useless `chunked_prefill_for_mla`

- vLLM version: release/v0.13.0
- vLLM main:
ad32e3e19c

Signed-off-by: wangxiyuan <wangxiyuan1007@gmail.com>

vllm_ascend/utils.py

@@ -1084,3 +1084,34 @@ def dispose_layer(layer: Any):
 def replace_layer(original_layer: Any, new_layer: Any):
     original_layer.__class__ = new_layer.__class__
     original_layer.__dict__ = new_layer.__dict__
+
+
+def check_kv_extra_config(vllm_config):
+
+    def _check(name: str, config: dict):
+        tp_key = "tp_size"
+        dp_key = "dp_size"
+        if tp_key in config:
+            config_tp = config[tp_key]
+            vllm_tp = vllm_config.parallel_config.tensor_parallel_size
+            if config_tp != vllm_tp:
+                raise ValueError(
+                    f"KV transfer '{name}' config has a conflicting tensor parallel size. "
+                    f"Expected {vllm_tp}, but got {config_tp}.")
+        if dp_key in config:
+            config_dp = config[dp_key]
+            vllm_dp = vllm_config.parallel_config.data_parallel_size
+            if config_dp != vllm_dp:
+                raise ValueError(
+                    f"KV transfer '{name}' config has a conflicting data parallel size. "
+                    f"Expected {vllm_dp}, but got {config_dp}.")
+
+    if vllm_config.kv_transfer_config.is_kv_producer:
+        _check(
+            "prefill",
+            vllm_config.kv_transfer_config.get_from_extra_config(
+                "prefill", {}))
+    if vllm_config.kv_transfer_config.is_kv_consumer:
+        _check(
+            "decode",
+            vllm_config.kv_transfer_config.get_from_extra_config("decode", {}))