[feature] Initial block diffusion language model support (#12588)

Co-authored-by: Tiwei Bie <tiwei.btw@antgroup.com>

python/sglang/srt/server_args.py

@@ -240,6 +240,10 @@ class ServerArgs:
     revision: Optional[str] = None
     model_impl: str = "auto"
 
+    # Diffusion LLM
+    dllm_algorithm: Optional[str] = None
+    dllm_block_size: Optional[int] = None
+
     # HTTP server
     host: str = "127.0.0.1"
     port: int = 30000
@@ -663,6 +667,9 @@ class ServerArgs:
         # Handle exporting request-level metrics.
         self._handle_request_metrics_exporters()
 
+        # Handle diffusion LLM inference.
+        self._handle_dllm_inference()
+
         # Handle any other necessary validations.
         self._handle_other_validations()
 
@@ -1974,6 +1981,30 @@ class ServerArgs:
                 "--export-metrics-to-file-dir is required when --export-metrics-to-file is enabled"
             )
 
+    def _handle_dllm_inference(self):
+        if self.dllm_algorithm is None:
+            return
+        if not self.disable_cuda_graph:
+            logger.warning(
+                "Cuda graph is disabled because of using diffusion LLM inference"
+            )
+            self.disable_cuda_graph = True
+        if not self.disable_overlap_schedule:
+            logger.warning(
+                "Overlap schedule is disabled because of using diffusion LLM inference"
+            )
+            self.disable_overlap_schedule = True
+        if not self.disable_radix_cache:
+            logger.warning(
+                "Radix cache is disabled because of using diffusion LLM inference"
+            )
+            self.disable_radix_cache = True
+        if not self.pp_size > 1:
+            logger.warning(
+                "Pipeline parallelism is disabled because of using diffusion LLM inference"
+            )
+            self.pp_size = 1
+
     def _handle_other_validations(self):
         # Handle model inference tensor dump.
         if self.debug_tensor_dump_output_folder is not None:
@@ -2093,6 +2124,20 @@ class ServerArgs:
             "implementation.\n",
         )
 
+        # Diffusion LLM
+        parser.add_argument(
+            "--dllm-algorithm",
+            type=str,
+            default=ServerArgs.dllm_algorithm,
+            help="The diffusion LLM algorithm.",
+        )
+        parser.add_argument(
+            "--dllm-block-size",
+            type=int,
+            default=ServerArgs.dllm_block_size,
+            help="The number of tokens processed in each iteration of the block diffusion LLM.",
+        )
+
         # HTTP server
         parser.add_argument(
             "--host",