def _linux_gpu_data():
    '''
    num_gpus: int
    gpus:
      - vendor: nvidia|amd|ati|...
        model: string
    '''
    if __opts__.get('enable_lspci', True) is False:
        return {}

    if __opts__.get('enable_gpu_grains', True) is False:
        return {}

    lspci = salt.utils.path.which('lspci')
    if not lspci:
        log.debug(
            'The `lspci` binary is not available on the system. GPU grains '
            'will not be available.'
        )
        return {}

    # dominant gpu vendors to search for (MUST be lowercase for matching below)
    known_vendors = ['nvidia', 'amd', 'ati', 'intel', 'cirrus logic', 'vmware', 'matrox', 'aspeed']
    gpu_classes = ('vga compatible controller', '3d controller')

    devs = []
    try:
        lspci_out = __salt__['cmd.run']('{0} -vmm'.format(lspci))

        cur_dev = {}
        error = False
        # Add a blank element to the lspci_out.splitlines() list,
        # otherwise the last device is not evaluated as a cur_dev and ignored.
        lspci_list = lspci_out.splitlines()
        lspci_list.append('')
        for line in lspci_list:
            # check for record-separating empty lines
            if line == '':
                if cur_dev.get('Class', '').lower() in gpu_classes:
                    devs.append(cur_dev)
                cur_dev = {}
                continue
            if re.match(r'^\w+:\s+.*', line):
                key, val = line.split(':', 1)
                cur_dev[key.strip()] = val.strip()
            else:
                error = True
                log.debug('Unexpected lspci output: \'%s\'', line)

        if error:
            log.warning(
                'Error loading grains, unexpected linux_gpu_data output, '
                'check that you have a valid shell configured and '
                'permissions to run lspci command'
            )
    except OSError:
        pass

    gpus = []
    for gpu in devs:
        vendor_strings = re.split('[^A-Za-z0-9]', gpu['Vendor'].lower())
        # default vendor to 'unknown', overwrite if we match a known one
        vendor = 'unknown'
        for name in known_vendors:
            # search for an 'expected' vendor name in the list of strings
            if name in vendor_strings:
                vendor = name
                break
        gpus.append({'vendor': vendor, 'model': gpu['Device']})

    grains = {}
    grains['num_gpus'] = len(gpus)
    grains['gpus'] = gpus
    return grains