arch_check.py

# SPDX-FileCopyrightText: Copyright (c) 2026 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
# SPDX-License-Identifier: LicenseRef-NVIDIA-SOFTWARE-LICENSE


from contextlib import contextmanager
from functools import cache

import pytest

from cuda.bindings import nvml


@cache
def hardware_supports_nvml():
    """
    Tries to call the simplest NVML API possible to see if just the basics
    works.  If not we are probably on one of the platforms where NVML is not
    supported at all (e.g. Jetson Orin).
    """
    nvml.init_v2()
    try:
        nvml.system_get_driver_branch()
    except (nvml.NotSupportedError, nvml.UnknownError):
        return False
    else:
        return True
    finally:
        nvml.shutdown()


@contextmanager
def unsupported_before(device: int, expected_device_arch: nvml.DeviceArch | str | None):
    device_arch = nvml.device_get_architecture(device)

    if isinstance(expected_device_arch, nvml.DeviceArch):
        expected_device_arch_int = int(expected_device_arch)
    elif expected_device_arch == "FERMI":
        expected_device_arch_int = 1
    else:
        expected_device_arch_int = 0

    if expected_device_arch is None or expected_device_arch == "HAS_INFOROM" or device_arch == nvml.DeviceArch.UNKNOWN:
        # In this case, we don't /know/ if it will fail, but we are ok if it
        # does or does not.

        # TODO: There are APIs that are documented as supported only if the
        # device has an InfoROM, but I couldn't find a way to detect that.  For
        # now, they are just handled as "possibly failing".

        try:
            yield
        except nvml.NotSupportedError:
            # The API call raised NotSupportedError, so we skip the test, but
            # don't fail it
            pytest.skip(
                f"Unsupported call for device architecture {nvml.DeviceArch(device_arch).name} "
                f"on device '{nvml.device_get_name(device)}'"
            )
        # If the API call worked, just continue
    elif int(device_arch) < expected_device_arch_int:
        # In this case, we /know/ if will fail, and we want to assert that it does.
        with pytest.raises(nvml.NotSupportedError):
            yield
        # The above call was unsupported, so the rest of the test is skipped
        pytest.skip(f"Unsupported before {expected_device_arch.name}, got {nvml.device_get_name(device)}")
    else:
        # In this case, we /know/ it should work, and if it fails, the test should fail.
        yield