[Platforms] Refactor xpu code (#10468)

Signed-off-by: MengqingCao <cmq0113@163.com>

vllm/platforms/xpu.py

@@ -1,9 +1,16 @@
+from typing import TYPE_CHECKING
+
 import torch
 
 from vllm.logger import init_logger
 
 from .interface import DeviceCapability, Platform, PlatformEnum, _Backend
 
+if TYPE_CHECKING:
+    from vllm.config import VllmConfig
+else:
+    VllmConfig = None
+
 logger = init_logger(__name__)
 
 
@@ -34,3 +41,17 @@ class XPUPlatform(Platform):
     @staticmethod
     def inference_mode():
         return torch.no_grad()
+
+    @classmethod
+    def check_and_update_config(cls, vllm_config: VllmConfig) -> None:
+        # check and update model config
+        model_config = vllm_config.model_config
+        if model_config.dtype == torch.bfloat16:
+            logger.warning(
+                "bfloat16 is not fully supported on XPU, casting to float16.")
+            model_config.dtype = torch.float16
+        if not model_config.enforce_eager:
+            logger.warning(
+                "CUDA graph is not supported on XPU, fallback to the eager "
+                "mode.")
+            model_config.enforce_eager = True