[platforms] enable platform plugins

.buildkite/test-pipeline.yaml

@@ -106,14 +106,12 @@ steps:
   source_file_dependencies:
   - vllm/
   commands:
-  - pip install -e ./plugins/vllm_add_dummy_model
   - pytest -v -s entrypoints/llm --ignore=entrypoints/llm/test_lazy_outlines.py --ignore=entrypoints/llm/test_generate.py --ignore=entrypoints/llm/test_generate_multiple_loras.py --ignore=entrypoints/llm/test_guided_generate.py
   - pytest -v -s entrypoints/llm/test_lazy_outlines.py # it needs a clean process
   - pytest -v -s entrypoints/llm/test_generate.py # it needs a clean process
   - pytest -v -s entrypoints/llm/test_generate_multiple_loras.py # it needs a clean process
   - pytest -v -s entrypoints/llm/test_guided_generate.py # it needs a clean process
   - pytest -v -s entrypoints/openai --ignore=entrypoints/openai/test_oot_registration.py
-  - pytest -v -s entrypoints/openai/test_oot_registration.py # it needs a clean process
   - pytest -v -s entrypoints/test_chat_utils.py
   - pytest -v -s entrypoints/offline_mode # Needs to avoid interference with other tests
 
@@ -333,8 +331,6 @@ steps:
   - vllm/
   - tests/models
   commands:
-    - pip install -e ./plugins/vllm_add_dummy_model
-    - pytest -v -s models/test_oot_registration.py # it needs a clean process
     - pytest -v -s models/test_registry.py
     - pytest -v -s models/test_initialization.py
 
@@ -469,11 +465,28 @@ steps:
   - pytest models/encoder_decoder/vision_language/test_broadcast.py -v -s -m 'distributed(num_gpus=2)'
   - pytest models/decoder_only/vision_language/test_models.py -v -s -m 'distributed(num_gpus=2)'
   - pytest -v -s spec_decode/e2e/test_integration_dist_tp2.py
-  - pip install -e ./plugins/vllm_add_dummy_model
-  - pytest -v -s distributed/test_distributed_oot.py
   - CUDA_VISIBLE_DEVICES=0,1 pytest -v -s test_sharded_state_loader.py
   - CUDA_VISIBLE_DEVICES=0,1 pytest -v -s kv_transfer/disagg_test.py
 
+- label: Plugin Tests (2 GPUs) # 40min
+  working_dir: "/vllm-workspace/tests"
+  num_gpus: 2
+  fast_check: true
+  source_file_dependencies:
+  - vllm/plugins/
+  - tests/plugins/
+  commands:
+  # begin platform plugin tests, all the code in-between runs on dummy platform
+  - pip install -e ./plugins/vllm_add_dummy_platform
+  - pytest -v -s plugins_tests/test_platform_plugins.py
+  - pip uninstall vllm_add_dummy_platform -y
+  # end platform plugin tests
+  # other tests continue here:
+  - pip install -e ./plugins/vllm_add_dummy_model
+  - pytest -v -s distributed/test_distributed_oot.py
+  - pytest -v -s entrypoints/openai/test_oot_registration.py # it needs a clean process
+  - pytest -v -s models/test_oot_registration.py # it needs a clean process
+
 - label: Multi-step Tests (4 GPUs) # 36min
   working_dir: "/vllm-workspace/tests"
   num_gpus: 4

docs/source/design/plugin_system.md

@@ -41,9 +41,11 @@ Every plugin has three parts:
 2. **Plugin name**: The name of the plugin. This is the value in the dictionary of the `entry_points` dictionary. In the example above, the plugin name is `register_dummy_model`. Plugins can be filtered by their names using the `VLLM_PLUGINS` environment variable. To load only a specific plugin, set `VLLM_PLUGINS` to the plugin name.
 3. **Plugin value**: The fully qualified name of the function to register in the plugin system. In the example above, the plugin value is `vllm_add_dummy_model:register`, which refers to a function named `register` in the `vllm_add_dummy_model` module.
 
-## What Can Plugins Do?
+## Types of supported plugins
 
-Currently, the primary use case for plugins is to register custom, out-of-the-tree models into vLLM. This is done by calling `ModelRegistry.register_model` to register the model. In the future, the plugin system may be extended to support more features, such as swapping in custom implementations for certain classes in vLLM.
+- **General plugins** (with group name `vllm.general_plugins`): The primary use case for these plugins is to register custom, out-of-the-tree models into vLLM. This is done by calling `ModelRegistry.register_model` to register the model inside the plugin function.
+
+- **Platform plugins** (with group name `vllm.platform_plugins`): The primary use case for these plugins is to register custom, out-of-the-tree platforms into vLLM. The plugin function should return `None` when the platform is not supported in the current environment, or the platform class's fully qualified name when the platform is supported.
 
 ## Guidelines for Writing Plugins
 

tests/conftest.py

@@ -31,7 +31,6 @@
                          to_enc_dec_tuple_list, zip_enc_dec_prompts)
 from vllm.logger import init_logger
 from vllm.outputs import RequestOutput
-from vllm.platforms import current_platform
 from vllm.sampling_params import BeamSearchParams
 from vllm.utils import (STR_DTYPE_TO_TORCH_DTYPE, cuda_device_count_stateless,
                         identity)
@@ -242,6 +241,7 @@ def video_assets() -> _VideoAssets:
 class HfRunner:
 
     def wrap_device(self, x: _T, device: Optional[str] = None) -> _T:
+        from vllm.platforms import current_platform
         if x is None or isinstance(x, (bool, )):
             return x
 

tests/plugins/vllm_add_dummy_platform/setup.py

@@ -0,0 +1,11 @@
+from setuptools import setup
+
+setup(
+    name='vllm_add_dummy_platform',
+    version='0.1',
+    packages=['vllm_add_dummy_platform'],
+    entry_points={
+        'vllm.platform_plugins': [
+            "dummy_platform_plugin = vllm_add_dummy_platform:dummy_platform_plugin"  # noqa
+        ]
+    })

tests/plugins/vllm_add_dummy_platform/vllm_add_dummy_platform/__init__.py

@@ -0,0 +1,5 @@
+from typing import Optional
+
+
+def dummy_platform_plugin() -> Optional[str]:
+    return "vllm_add_dummy_platform.dummy_platform.DummyPlatform"

tests/plugins/vllm_add_dummy_platform/vllm_add_dummy_platform/dummy_platform.py

@@ -0,0 +1,5 @@
+from vllm.platforms.cuda import CudaPlatform
+
+
+class DummyPlatform(CudaPlatform):
+    device_name = "DummyDevice"

tests/plugins_tests/test_platform_plugins.py

@@ -0,0 +1,16 @@
+def test_platform_plugins():
+    # simulate workload by running an example
+    import runpy
+    current_file = __file__
+    import os
+    example_file = os.path.join(
+        os.path.dirname(os.path.dirname(os.path.dirname(current_file))),
+        "examples", "offline_inference.py")
+    runpy.run_path(example_file)
+
+    # check if the plugin is loaded correctly
+    from vllm.platforms import _init_trace, current_platform
+    assert current_platform.device_name == "DummyDevice", (
+        f"Expected DummyDevice, got {current_platform.device_name}, "
+        "possibly because current_platform is imported before the plugin"
+        f" is loaded. The first import:\n{_init_trace}")

vllm/config.py

@@ -22,7 +22,7 @@
 from vllm.model_executor.layers.quantization import (QUANTIZATION_METHODS,
                                                      get_quantization_config)
 from vllm.model_executor.models import ModelRegistry
-from vllm.platforms import current_platform, interface
+from vllm.platforms import CpuArchEnum
 from vllm.tracing import is_otel_available, otel_import_error_traceback
 from vllm.transformers_utils.config import (
     ConfigFormat, get_config, get_hf_image_processor_config,
@@ -343,6 +343,7 @@ def __init__(self,
         self.is_hybrid = self._init_is_hybrid()
         self.has_inner_state = self._init_has_inner_state()
 
+        from vllm.platforms import current_platform
         if current_platform.is_neuron():
             self.override_neuron_config = override_neuron_config
         else:
@@ -583,6 +584,7 @@ def _verify_quantization(self) -> None:
                 raise ValueError(
                     f"Unknown quantization method: {self.quantization}. Must "
                     f"be one of {supported_quantization}.")
+            from vllm.platforms import current_platform
             current_platform.verify_quantization(self.quantization)
             if self.quantization not in optimized_quantization_methods:
                 logger.warning(
@@ -638,6 +640,7 @@ def verify_async_output_proc(self, parallel_config, speculative_config,
 
         # Reminder: Please update docs/source/usage/compatibility_matrix.md
         # If the feature combo become valid
+        from vllm.platforms import current_platform
         if not current_platform.is_async_output_supported(self.enforce_eager):
             logger.warning(
                 "Async output processing is not supported on the "
@@ -1006,6 +1009,7 @@ def _verify_args(self) -> None:
             raise ValueError(
                 "GPU memory utilization must be less than 1.0. Got "
                 f"{self.gpu_memory_utilization}.")
+        from vllm.platforms import current_platform
         if (current_platform.is_cuda() and self.block_size is not None
                 and self.block_size > 32):
             raise ValueError("CUDA Paged Attention kernel only supports "
@@ -1273,6 +1277,7 @@ def __post_init__(self) -> None:
                                  f"distributed executor backend "
                                  f"'{self.distributed_executor_backend}'.")
         ray_only_devices = ["tpu", "hpu"]
+        from vllm.platforms import current_platform
         if (current_platform.device_type in ray_only_devices
                 and self.world_size > 1):
             if self.distributed_executor_backend is None:
@@ -1321,7 +1326,7 @@ def use_ray(self) -> bool:
     def _verify_args(self) -> None:
         # Lazy import to avoid circular import
         from vllm.executor.executor_base import ExecutorBase
-
+        from vllm.platforms import current_platform
         if self.distributed_executor_backend not in (
                 "ray", "mp", None) and not (isinstance(
                     self.distributed_executor_backend, type) and issubclass(
@@ -1522,6 +1527,7 @@ def compute_hash(self) -> str:
     def __init__(self, device: str = "auto") -> None:
         if device == "auto":
             # Automated device type detection
+            from vllm.platforms import current_platform
             self.device_type = current_platform.device_type
             if not self.device_type:
                 raise RuntimeError("Failed to infer device type")
@@ -2235,9 +2241,10 @@ def _get_and_verify_dtype(
             else:
                 torch_dtype = config_dtype
 
+            from vllm.platforms import current_platform
             if (current_platform.is_cpu()
                     and current_platform.get_cpu_architecture()
-                    == interface.CpuArchEnum.POWERPC
+                    == CpuArchEnum.POWERPC
                     and (config_dtype == torch.float16
                          or config_dtype == torch.float32)):
                 logger.info(
@@ -3052,6 +3059,7 @@ def _get_quantization_config(
             model_config: ModelConfig,
             load_config: LoadConfig) -> Optional[QuantizationConfig]:
         """Get the quantization config."""
+        from vllm.platforms import current_platform
         if model_config.quantization is not None:
             from vllm.model_executor.model_loader.weight_utils import (
                 get_quant_config)
@@ -3114,6 +3122,7 @@ def __post_init__(self):
             self.quant_config = VllmConfig._get_quantization_config(
                 self.model_config, self.load_config)
 
+        from vllm.platforms import current_platform
         if self.scheduler_config is not None and \
             self.model_config is not None and \
             self.scheduler_config.chunked_prefill_enabled and \

vllm/distributed/parallel_state.py

@@ -39,7 +39,6 @@
 import vllm.envs as envs
 from vllm.distributed.utils import StatelessProcessGroup
 from vllm.logger import init_logger
-from vllm.platforms import current_platform
 from vllm.utils import direct_register_custom_op, supports_custom_op
 
 if TYPE_CHECKING:
@@ -194,6 +193,7 @@ def __init__(
         assert self.cpu_group is not None
         assert self.device_group is not None
 
+        from vllm.platforms import current_platform
         if current_platform.is_cuda_alike():
             self.device = torch.device(f"cuda:{local_rank}")
         else:
@@ -1188,6 +1188,7 @@ def cleanup_dist_env_and_memory(shutdown_ray: bool = False):
         import ray  # Lazy import Ray
         ray.shutdown()
     gc.collect()
+    from vllm.platforms import current_platform
     if not current_platform.is_cpu():
         torch.cuda.empty_cache()
 

vllm/engine/arg_utils.py

@@ -18,7 +18,6 @@
 from vllm.executor.executor_base import ExecutorBase
 from vllm.logger import init_logger
 from vllm.model_executor.layers.quantization import QUANTIZATION_METHODS
-from vllm.platforms import current_platform
 from vllm.transformers_utils.utils import check_gguf_file
 from vllm.usage.usage_lib import UsageContext
 from vllm.utils import FlexibleArgumentParser, StoreBoolean
@@ -1094,6 +1093,7 @@ def create_engine_config(self,
                 use_sliding_window = (model_config.get_sliding_window()
                                       is not None)
                 use_spec_decode = self.speculative_model is not None
+                from vllm.platforms import current_platform
                 if (is_gpu and not use_sliding_window and not use_spec_decode
                         and not self.enable_lora
                         and not self.enable_prompt_adapter

vllm/executor/ray_utils.py

@@ -8,7 +8,6 @@
 from vllm.config import ParallelConfig
 from vllm.executor.msgspec_utils import decode_hook, encode_hook
 from vllm.logger import init_logger
-from vllm.platforms import current_platform
 from vllm.sequence import ExecuteModelRequest, IntermediateTensors
 from vllm.utils import get_ip
 from vllm.worker.worker_base import WorkerWrapperBase
@@ -229,6 +228,7 @@ def initialize_ray_cluster(
             the default Ray cluster address.
     """
     assert_ray_available()
+    from vllm.platforms import current_platform
 
     # Connect to a ray cluster.
     if current_platform.is_rocm() or current_platform.is_xpu():

vllm/model_executor/guided_decoding/__init__.py

@@ -6,7 +6,7 @@
 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 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,
@@ -272,6 +271,7 @@ 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 @@
 
 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)