[platforms] enable platform plugins (#11602)

Signed-off-by: youkaichao <youkaichao@gmail.com>

vllm/model_executor/guided_decoding/__init__.py

@@ -6,7 +6,7 @@ from vllm.logger import init_logger
 from vllm.model_executor.guided_decoding.utils import (
     convert_lark_to_gbnf, grammar_is_likely_lark,
     has_lmf_unsupported_json_features, has_xgrammar_unsupported_json_features)
-from vllm.platforms import CpuArchEnum, current_platform
+from vllm.platforms import CpuArchEnum
 
 if TYPE_CHECKING:
     from transformers import PreTrainedTokenizer
@@ -39,6 +39,7 @@ def maybe_backend_fallback(
 
     if guided_params.backend == "xgrammar":
         # xgrammar only has x86 wheels for linux, fallback to outlines
+        from vllm.platforms import current_platform
         if current_platform.get_cpu_architecture() is not CpuArchEnum.X86:
             logger.warning("xgrammar is only supported on x86 CPUs. "
                            "Falling back to use outlines instead.")

vllm/model_executor/models/registry.py

@@ -18,7 +18,6 @@ import cloudpickle
 import torch.nn as nn
 
 from vllm.logger import init_logger
-from vllm.platforms import current_platform
 
 from .interfaces import (has_inner_state, is_attention_free, is_hybrid,
                          supports_cross_encoding, supports_multimodal,
@@ -273,6 +272,7 @@ def _try_load_model_cls(
     model_arch: str,
     model: _BaseRegisteredModel,
 ) -> Optional[Type[nn.Module]]:
+    from vllm.platforms import current_platform
     current_platform.verify_model_arch(model_arch)
     try:
         return model.load_model_cls()

vllm/model_executor/utils.py

@@ -3,10 +3,9 @@ from typing import Any, Dict, Optional
 
 import torch
 
-from vllm.platforms import current_platform
-
 
 def set_random_seed(seed: int) -> None:
+    from vllm.platforms import current_platform
     current_platform.seed_everything(seed)
 
 
@@ -38,6 +37,7 @@ def set_weight_attrs(
         # This sometimes causes OOM errors during model loading. To avoid this,
         # we sync the param tensor after its weight loader is called.
         # TODO(woosuk): Remove this hack once we have a better solution.
+        from vllm.platforms import current_platform
         if current_platform.is_tpu() and key == "weight_loader":
             value = _make_synced_weight_loader(value)
         setattr(weight, key, value)