优化VLLM_DISABLE_DSA的设置，加入envs中，默认关，开启可强制关闭dsa

vllm/envs.py

@@ -323,6 +323,7 @@ if TYPE_CHECKING:
     USE_LIGHTOP_PER_TOKEN_GROUP_QUANT_FP8: bool = False
     USE_LIGHTOP_TOPK: bool = False
     USE_LIGHTOP_CONVERT_REQ_INDEX_TO_GLOBAL_INDEX: bool = False
+    VLLM_DISABLE_DSA: bool = False
 def get_default_cache_root():
     return os.getenv(
         "XDG_CACHE_HOME",
@@ -2002,7 +2003,10 @@ environment_variables: dict[str, Callable[[], Any]] = {
     "USE_LIGHTOP_CONVERT_REQ_INDEX_TO_GLOBAL_INDEX":
         lambda: (os.environ.get("USE_LIGHTOP_CONVERT_REQ_INDEX_TO_GLOBAL_INDEX", "False").lower() in
                     ("true", "1")),               
-
+    #If set to 1/True, disenable the DSA.
+    "VLLM_DISABLE_DSA":
+        lambda: (os.environ.get("VLLM_DISABLE_DSA", "False").lower() in
+                    ("true", "1")),  
 }
 
 # --8<-- [end:env-vars-definition]

vllm/model_executor/models/config.py

@@ -3,6 +3,7 @@
 from copy import deepcopy
 from math import lcm
 from typing import TYPE_CHECKING
+from vllm import envs
 
 from vllm.logger import init_logger
 from vllm.model_executor.models import ModelRegistry
@@ -554,7 +555,8 @@ class DeepseekV32ForCausalLM(VerifyAndUpdateConfig):
 
         # For DeepSeekV3.2, a custom fp8 format is used when fp8 kv-cache is enabled.
         cache_config = vllm_config.cache_config
-        if cache_config.cache_dtype.startswith("fp8"):
+        force_disable_dsa = envs.VLLM_DISABLE_DSA
+        if cache_config.cache_dtype.startswith("fp8") and not force_disable_dsa:
             cache_config.cache_dtype = "fp8_ds_mla"
             logger.info("Using custom fp8 kv-cache format for DeepSeekV3.2")
         if cache_config.cache_dtype == "bfloat16":

vllm/model_executor/models/deepseek_mtp.py

@@ -80,7 +80,7 @@ class DeepSeekMultiTokenPredictorLayer(nn.Module):
         self.device = current_platform.device_type
 
         #添加判断，默认开启DSA
-        force_disable_dsa = os.environ.get("VLLM_DISABLE_DSA", "0") == "1"
+        force_disable_dsa = envs.VLLM_DISABLE_DSA
         self.is_v32 = hasattr(config, "index_topk") and not force_disable_dsa
         if self.is_v32:
             topk_tokens = config.index_topk

vllm/model_executor/models/deepseek_v2.py

@@ -901,7 +901,7 @@ class DeepseekV2MLAAttention(nn.Module):
             mscale = yarn_get_mscale(scaling_factor, float(mscale_all_dim))
             self.scaling = self.scaling * mscale * mscale
         #添加判断，默认开启DSA
-        force_disable_dsa = os.environ.get("VLLM_DISABLE_DSA", "0") == "1"
+        force_disable_dsa = envs.VLLM_DISABLE_DSA
         self.is_v32 = hasattr(config, "index_topk") and not force_disable_dsa
 
         if self.is_v32:
@@ -1219,7 +1219,7 @@ class DeepseekV2Model(nn.Module):
 
         self.vocab_size = config.vocab_size
         #添加判断，默认开启DSA
-        force_disable_dsa = os.environ.get("VLLM_DISABLE_DSA", "0") == "1"
+        force_disable_dsa = envs.VLLM_DISABLE_DSA
         self.is_v32 = hasattr(config, "index_topk") and not force_disable_dsa        
 
         if self.is_v32: