Fix FP8 KV Cache Support in FA3 Backend (#7148)

python/sglang/srt/model_executor/model_runner.py

@@ -239,7 +239,7 @@ class ModelRunner:
                 "SGLANG_LOG_EXPERT_LOCATION_METADATA"
             ):
                 logger.info(
-                    f"Initial expert_location_metadata: {get_global_expert_location_metadata().debug_str()}"
+                    f"Initial expert_location_metadata: {get_global_expert_location_metadata()}"
                 )
 
             set_global_expert_distribution_recorder(
@@ -866,7 +866,9 @@ class ModelRunner:
             else:
                 self.kv_cache_dtype = torch.float8_e5m2
         elif self.server_args.kv_cache_dtype == "fp8_e4m3":
-            if is_cuda():
+            if _is_hip:  # Using natively supported format
+                self.kv_cache_dtype = torch.float8_e4m3fnuz
+            else:
                 self.kv_cache_dtype = torch.float8_e4m3fn
         else:
             raise ValueError(