# SPDX-License-Identifier: Apache-2.0 # SPDX-FileCopyrightText: Copyright contributors to the vLLM project from typing import Optional import torch.nn as nn from vllm.config import get_cached_compilation_config from vllm.logger import init_logger from vllm.platforms import current_platform logger = init_logger(__name__) class CustomOp(nn.Module): """ Base class for custom ops. Dispatches the forward method to the appropriate backend. """ def __new__(cls, *args, **kwargs): try: op_name = cls.__name__ except AttributeError: raise TypeError( f"Cannot instantiate '{cls.__name__}': its 'name' attribute " f"was not set, possibly because it was not decorated with " f"@CustomOp.register, or it's the CustomOp base class itself." ) from None if op_name not in cls.op_registry_oot: op_cls_to_instantiate = cls else: op_cls_to_instantiate = cls.op_registry_oot[op_name] logger.debug("Instantiating custom op: %s using %s", op_name, str(op_cls_to_instantiate)) return super().__new__(op_cls_to_instantiate) def __init__(self): super().__init__() self._forward_method = self.dispatch_forward() def forward(self, *args, **kwargs): return self._forward_method(*args, **kwargs) def forward_native(self, *args, **kwargs): """PyTorch-native implementation of the forward method. This method is optional. If implemented, it can be used with compilers such as torch.compile or PyTorch XLA. Also, it can be used for testing purposes. """ raise NotImplementedError def forward_cuda(self, *args, **kwargs): raise NotImplementedError def forward_hip(self, *args, **kwargs): # By default, we assume that HIP ops are compatible with CUDA ops. return self.forward_cuda(*args, **kwargs) def forward_xpu(self, *args, **kwargs): # By default, we assume that XPU ops are compatible with the # PyTorch-native implementation. return self.forward_native(*args, **kwargs) def forward_cpu(self, *args, **kwargs): # By default, we assume that CPU ops are compatible with CUDA ops. return self.forward_cuda(*args, **kwargs) def forward_tpu(self, *args, **kwargs): # By default, we assume that TPU ops are compatible with the # PyTorch-native implementation. # NOTE(woosuk): This is a placeholder for future extensions. return self.forward_native(*args, **kwargs) def forward_neuron(self, *args, **kwargs): # By default, we assume that Neuron ops are compatible with the # PyTorch-native implementation. return self.forward_native(*args, **kwargs) def forward_oot(self, *args, **kwargs): # By default, we assume that OOT ops are compatible with the # PyTorch-native implementation. return self.forward_native(*args, **kwargs) def dispatch_forward(self): # NOTE(woosuk): Here we assume that vLLM was built for only one # specific backend. Currently, we do not support dynamic dispatching. compilation_config = get_cached_compilation_config() enabled = self.enabled() if enabled: compilation_config.enabled_custom_ops.update([self.__class__.name]) else: compilation_config.disabled_custom_ops.update( [self.__class__.name]) if not enabled: return self.forward_native if current_platform.is_rocm(): return self.forward_hip elif current_platform.is_cpu(): return self.forward_cpu elif current_platform.is_tpu(): return self.forward_tpu elif current_platform.is_xpu(): return self.forward_xpu elif current_platform.is_neuron(): return self.forward_neuron elif current_platform.is_out_of_tree(): return self.forward_oot else: return self.forward_cuda @classmethod def enabled(cls) -> bool: # if no name, then it was not registered compilation_config = get_cached_compilation_config() custom_ops = compilation_config.custom_ops if not hasattr(cls, "name"): logger.warning_once( "Custom op %s was not registered, which means it won't appear in the op registry. It will be enabled/disabled based on the global settings.", # noqa: E501 cls.__name__, ) return CustomOp.default_on() enabled = f"+{cls.name}" in custom_ops disabled = f"-{cls.name}" in custom_ops assert not (enabled and disabled), f"Cannot enable and disable {cls.name}" return (CustomOp.default_on() or enabled) and not disabled @staticmethod def default_on() -> bool: """ On by default if PyTorch Inductor is not used. Specifying 'all' or 'none' in custom_op takes precedence. """ from vllm.config import CompilationLevel compilation_config = get_cached_compilation_config() default_on = (compilation_config.level < CompilationLevel.PIECEWISE or not compilation_config.use_inductor) count_none = compilation_config.custom_ops.count("none") count_all = compilation_config.custom_ops.count("all") return default_on and not count_none > 0 or count_all > 0 # Dictionary of all custom ops (classes, indexed by registered name). # To check if an op with a name is enabled, call .enabled() on the class. # Examples: # - MyOp.enabled() # - op_registry["my_op"].enabled() op_registry: dict[str, type['CustomOp']] = {} op_registry_oot: dict[str, type['CustomOp']] = {} # Decorator to register custom ops. @classmethod def register(cls, name: str): def decorator(op_cls): assert name not in cls.op_registry, f"Duplicate op name: {name}" op_cls.name = name cls.op_registry[name] = op_cls return op_cls return decorator # Decorator to register out-of-tree(oot) custom ops. # For OOT custom ops: # if in-tree layer class is registered with an oot_custom_op layer, # the oot_custom_op layer will be used instead. # Example: # - @UnquantizedFusedMoEMethod.register_oot # class HPUUnquantizedFusedMoEMethod(UnquantizedFusedMoEMethod) # or # - @CustomOP.register_oot(name="UnquantizedFusedMoEMethod") @classmethod def register_oot(cls, _decorated_op_cls=None, name: Optional[str] = None): def decorator(op_cls): reg_name = name if name is not None else cls.__name__ assert reg_name not in cls.op_registry_oot, \ f"Duplicate op name: {reg_name}" op_cls.name = reg_name cls.op_registry_oot[reg_name] = op_cls return op_cls if _decorated_op_cls is None: # Called with parentheses: @CustomOP.register_oot() # or @CustomOP.register_oot(name="...") # So, _decorated_op_cls is None. # We return the actual decorator function. return decorator elif isinstance(_decorated_op_cls, type): # Check if it's a class # Called without parentheses: @CustomOP.register_oot # The first argument is the class itself. # We call the 'decorator' function immediately with the class. return decorator(_decorated_op_cls) else: # Handle other unexpected cases if necessary raise TypeError("Decorator can only be applied to classes.")