gpu_discover.cpp

#include <level_zero/ze_api.h>
#include <cstdlib>
#include <iostream>

#define L0_SAFE_CALL(call)                                                     \
  {                                                                            \
    auto status = (call);                                                      \
    if (status) {                                                              \
      std::cerr << "L0 error: " << std::hex << (int)status << " ";             \
      std::cerr << std::dec << __FILE__ << ":" << __LINE__ << std::endl;       \
      exit(status);                                                            \
    }                                                                          \
  }

int main() {
  // Initialize the driver
  L0_SAFE_CALL(zeInit(0));

  // Discover all the driver instances
  uint32_t driverCount = 0;
  L0_SAFE_CALL(zeDriverGet(&driverCount, nullptr));
  ze_driver_handle_t *allDrivers = (ze_driver_handle_t *)malloc(driverCount * sizeof(ze_driver_handle_t));
  L0_SAFE_CALL(zeDriverGet(&driverCount, allDrivers));

  // Find a driver instance with a GPU device
  ze_driver_handle_t hDriver = nullptr;
  ze_device_handle_t hDevice = nullptr;
  for (uint32_t i = 0; i < driverCount; ++i) {
    uint32_t deviceCount = 0;
    L0_SAFE_CALL(zeDeviceGet(allDrivers[i], &deviceCount, nullptr));
    ze_device_handle_t *allDevices = (ze_device_handle_t *)malloc(deviceCount * sizeof(ze_device_handle_t));
    L0_SAFE_CALL(zeDeviceGet(allDrivers[i], &deviceCount, allDevices));

    for (uint32_t d = 0; d < deviceCount; ++d) {
      ze_device_properties_t device_properties;
      L0_SAFE_CALL(zeDeviceGetProperties(allDevices[d], &device_properties));

      if (ZE_DEVICE_TYPE_GPU == device_properties.type) {
        hDriver = allDrivers[i];
        hDevice = allDevices[d];
        break;
      }
    }

    free(allDevices);
    if (nullptr != hDriver) {
      break;
    }
  }

  free(allDrivers);
  if (nullptr == hDevice) {
    std::cerr << "No GPU devices found" << std::endl;
    return 0;
  }
  std::cout << "GPU found." << std::endl;
}