[DeepSeek V4] Default FP4 checkpoints to FlashInfer MXFP4 MoE (#35919)

python/sglang/srt/arg_groups/overrides.py

@@ -1164,16 +1164,27 @@ def _deepseek_v4_overrides(server_args: Any, hf_config: Any) -> dict:
         overrides["swa_full_tokens_ratio"] = 0.1
         logger.info(f"Setting swa_full_tokens_ratio to 0.1 for {model_arch}.")
 
-    # nvidia/DeepSeek-V4-Pro-NVFP4 uses flashinfer_trtllm_routed MoE runner backend.
-    if (
-        server_args.moe_runner_backend == "auto"
-        and server_args.get_model_config().nvfp4_moe_meta is not None
-    ):
-        overrides["moe_runner_backend"] = "flashinfer_trtllm_routed"
-        logger.info(
-            "Use flashinfer_trtllm_routed as MoE runner backend for "
-            f"{model_arch} hybrid FP8+NVFP4 checkpoint."
-        )
+    if server_args.moe_runner_backend == "auto":
+        model_config = server_args.get_model_config()
+        # nvidia/DeepSeek-V4-Pro-NVFP4 uses the routed TRT-LLM runner.
+        if model_config.nvfp4_moe_meta is not None:
+            overrides["moe_runner_backend"] = "flashinfer_trtllm_routed"
+            logger.info(
+                "Use flashinfer_trtllm_routed as MoE runner backend for "
+                f"{model_arch} hybrid FP8+NVFP4 checkpoint."
+            )
+        elif (
+            server_args.device == "cuda"
+            and not is_hip()
+            and server_args.moe_a2a_backend == "none"
+            and not envs.SGLANG_DSV4_FP4_DEQUANT.get()
+            and model_config.is_fp4_experts
+            and (is_sm90_supported() or is_sm100_supported() or is_sm120_supported())
+        ):
+            overrides["moe_runner_backend"] = "flashinfer_mxfp4"
+            logger.info(
+                "Use flashinfer_mxfp4 as MoE runner backend for " f"{model_arch}."
+            )
     return overrides
 
 
@@ -1921,20 +1932,6 @@ def _deepseek_v4_kv_cache_dtype(view: Any) -> dict:
     return {}
 
 
-@register_post_process
-def _deepseek_v4_sm120_moe(view: Any) -> dict:
-    """Default DeepSeek V4 MXFP4 experts to FlashInfer CUTLASS on SM120."""
-    hf_config = view.get_model_config().hf_config
-    if hf_config.architectures[0] != "DeepseekV4ForCausalLM":
-        return {}
-    if is_sm120_supported() and view.moe_runner_backend == "auto":
-        logger.info(
-            "Use flashinfer_mxfp4 as MoE runner backend on SM120 for DeepseekV4"
-        )
-        return {"moe_runner_backend": "flashinfer_mxfp4"}
-    return {}
-
-
 @_register_for("MuseGlimmerForConditionalGeneration", "MuseGlimmerForCausalLM")
 def _muse_glimmer_fp4_gemm_runner_overrides(server_args: Any, hf_config: Any) -> dict:
     if is_sm120_supported() and server_args.fp4_gemm_runner_backend == "auto":

python/sglang/srt/server_args.py

@@ -5540,15 +5540,6 @@ class ServerArgs:
             validate_deepseek_v4_cp(self)
             validate_deepseek_v4_mega_moe_token_budget(self)
 
-            # The SM120 marlin fallback moved to the resolution pipeline
-            # (arg_groups/overrides.py: _deepseek_v4_sm120_moe), invoked here
-            # at its legacy slot.
-            from sglang.srt.arg_groups.overrides import (
-                _deepseek_v4_sm120_moe,
-                run_post_process_pass,
-            )
-
-            run_post_process_pass(self, _deepseek_v4_sm120_moe)
             if is_sm120_supported():
                 # SM120 lacks tcgen05/TMEM: disable features that depend on
                 # DeepGEMM or require >99KB SMEM (topk_v2).