[Neuron] Add an option to build with neuron (#2065)

requirements-neuron.txt

+sentencepiece  # Required for LLaMA tokenizer.
+numpy
+transformers-neuronx >= 0.9.0
+torch-neuronx >= 2.1.0
+neuronx-cc
+fastapi
+uvicorn[standard]
+pydantic == 1.10.13  # Required for OpenAI server.
+aioprometheus[starlette]

setup.py

@@ -24,8 +24,17 @@ def _is_hip() -> bool:
     return torch.version.hip is not None
 
 
+def _is_neuron() -> bool:
+    torch_neuronx_installed = True
+    try:
+        subprocess.run(["neuron-ls"], capture_output=True, check=True)
+    except FileNotFoundError as e:
+        torch_neuronx_installed = False
+    return torch_neuronx_installed
+
+
 def _is_cuda() -> bool:
-    return torch.version.cuda is not None
+    return (torch.version.cuda is not None) and not _is_neuron()
 
 
 # Compiler flags.
@@ -87,6 +96,24 @@ def get_hipcc_rocm_version():
         return None
 
 
+def get_neuronxcc_version():
+    import sysconfig
+    site_dir = sysconfig.get_paths()["purelib"]
+    version_file = os.path.join(site_dir, "neuronxcc", "version", "__init__.py")
+
+    # Check if the command was executed successfully
+    with open(version_file, "rt") as fp:
+        content = fp.read()
+
+    # Extract the version using a regular expression
+    match = re.search(r"__version__ = '(\S+)'", content)
+    if match:
+        # Return the version string
+        return match.group(1)
+    else:
+        raise RuntimeError("Could not find HIP version in the output")
+
+
 def get_nvcc_cuda_version(cuda_dir: str) -> Version:
     """Get the CUDA version from nvcc.
 
@@ -210,6 +237,9 @@ elif _is_hip():
             f"Only the following arch is supported: {ROCM_SUPPORTED_ARCHS}"
             f"amdgpu_arch_found: {amd_arch}")
 
+elif _is_neuron():
+    neuronxcc_version = get_neuronxcc_version()
+
 ext_modules = []
 
 vllm_extension_sources = [
@@ -227,15 +257,16 @@ vllm_extension_sources = [
 if _is_cuda():
     vllm_extension_sources.append("csrc/quantization/awq/gemm_kernels.cu")
 
-vllm_extension = CUDAExtension(
-    name="vllm._C",
-    sources=vllm_extension_sources,
-    extra_compile_args={
-        "cxx": CXX_FLAGS,
-        "nvcc": NVCC_FLAGS,
-    },
-)
-ext_modules.append(vllm_extension)
+if not _is_neuron():
+    vllm_extension = CUDAExtension(
+        name="vllm._C",
+        sources=vllm_extension_sources,
+        extra_compile_args={
+            "cxx": CXX_FLAGS,
+            "nvcc": NVCC_FLAGS,
+        },
+    )
+    ext_modules.append(vllm_extension)
 
 
 def get_path(*filepath) -> str:
@@ -264,6 +295,12 @@ def get_vllm_version() -> str:
         if hipcc_version != MAIN_CUDA_VERSION:
             rocm_version_str = hipcc_version.replace(".", "")[:3]
             version += f"+rocm{rocm_version_str}"
+    elif _is_neuron():
+        # Get the Neuron version
+        neuron_version = str(neuronxcc_version)
+        if neuron_version != MAIN_CUDA_VERSION:
+            neuron_version_str = neuron_version.replace(".", "")[:3]
+            version += f"+neuron{neuron_version_str}"
     else:
         cuda_version = str(nvcc_cuda_version)
         if cuda_version != MAIN_CUDA_VERSION:
@@ -287,6 +324,9 @@ def get_requirements() -> List[str]:
     if _is_hip():
         with open(get_path("requirements-rocm.txt")) as f:
             requirements = f.read().strip().split("\n")
+    elif _is_neuron():
+        with open(get_path("requirements-neuron.txt")) as f:
+            requirements = f.read().strip().split("\n")
     else:
         with open(get_path("requirements.txt")) as f:
             requirements = f.read().strip().split("\n")
@@ -325,6 +365,6 @@ setuptools.setup(
     python_requires=">=3.8",
     install_requires=get_requirements(),
     ext_modules=ext_modules,
-    cmdclass={"build_ext": BuildExtension},
+    cmdclass={"build_ext": BuildExtension} if not _is_neuron() else {},
     package_data=package_data,
 )

vllm/utils.py

@@ -8,8 +8,6 @@ from typing import List
 import psutil
 import torch
 
-from vllm._C import cuda_utils
-
 
 class Device(enum.Enum):
     GPU = enum.auto()
@@ -36,6 +34,10 @@ def is_hip() -> bool:
 
 def get_max_shared_memory_bytes(gpu: int = 0) -> int:
     """Returns the maximum shared memory per thread block in bytes."""
+    # NOTE: This import statement should be executed lazily since
+    # the Neuron-X backend does not have the `cuda_utils` module.
+    from vllm._C import cuda_utils
+
     # https://docs.nvidia.com/cuda/cuda-runtime-api/group__CUDART__TYPES.html
     cudaDevAttrMaxSharedMemoryPerBlockOptin = 97 if not is_hip() else 74
     max_shared_mem = cuda_utils.get_device_attribute(