def METHOD_NAME(hv_flag):
    """
    Boot the guest, with param cpu_model_flags set to hv_flag
    param hv_flag: the hv flags to set to cpu
    return: the booted vm
    """
    params["cpu_model_flags"] = hv_flag
    params["start_vm"] = "yes"
    vm_name = params["main_vm"]
    env_process.preprocess(test, params, env)
    return env.get_vm(vm_name)