[Feature] LMCache Connector Integration (#9741)

Signed-off-by: Oasis-Git <ayw.sirius19@gmail.com>
Signed-off-by: YuhanLiu11 <yliu738@wisc.edu>
Co-authored-by: Zhiqiang Xie <xiezhq@stanford.edu>

python/sglang/srt/server_args.py

@@ -303,6 +303,8 @@ class ServerArgs:
     hicache_storage_backend: Optional[str] = None
     hicache_storage_prefetch_policy: str = "best_effort"
     hicache_storage_backend_extra_config: Optional[str] = None
+    # LMCache
+    enable_lmcache: bool = False
 
     # Double Sparsity
     enable_double_sparsity: bool = False
@@ -1735,6 +1737,12 @@ class ServerArgs:
             default=ServerArgs.hicache_storage_backend_extra_config,
             help="A dictionary in JSON string format containing extra configuration for the storage backend.",
         )
+        # LMCache
+        parser.add_argument(
+            "--enable-lmcache",
+            action="store_true",
+            help="Using LMCache as an alternative hierarchical cache solution",
+        )
 
         # Double Sparsity
         parser.add_argument(