[XPU] remove common path warning log (#33769)

Signed-off-by: Kunshang Ji <kunshang.ji@intel.com>

vllm/platforms/__init__.py

@@ -140,11 +140,6 @@ def xpu_platform_plugin() -> str | None:
 
             XPUPlatform.dist_backend = dist_backend
             logger.debug("Confirmed %s backend is available.", XPUPlatform.dist_backend)
-        else:
-            logger.warning(
-                "xccl is not enabled in this torch build, "
-                "communication is not available."
-            )
 
         if hasattr(torch, "xpu") and torch.xpu.is_available():
             is_xpu = True

vllm/platforms/xpu.py

@@ -34,7 +34,7 @@ class XPUPlatform(Platform):
     # Intel XPU's device key is "GPU" for Ray.
     # see https://github.com/ray-project/ray/blob/6a5eb5865eeb9ccf058a79b44f107e327e360673/python/ray/_private/accelerators/intel_gpu.py#L20 # noqa: E501
     ray_device_key: str = "GPU"
-    dist_backend: str = "ccl"  # ccl | xccl
+    dist_backend: str = "xccl"  # xccl only
     device_control_env_var: str = "ZE_AFFINITY_MASK"
 
     @classmethod
@@ -223,6 +223,13 @@ class XPUPlatform(Platform):
 
     @classmethod
     def get_device_communicator_cls(cls) -> str:
+        from vllm.utils.torch_utils import supports_xccl
+
+        if not supports_xccl():
+            logger.warning(
+                "xccl is not enabled in this torch build, communication"
+                " is not available."
+            )
         return "vllm.distributed.device_communicators.xpu_communicator.XpuCommunicator"  # noqa
 
     @classmethod