'Get host PCI devices information.
Obtains PCI devices information and returns it as a JSON string.
:returns: a JSON string containing a list of the assignable PCI
devices information.'

def _get_pci_passthrough_devices(self):

    pci_devices = self._hostutils.get_pci_passthrough_devices()
    for pci_dev in pci_devices:
        dev_label = ('label_%(vendor_id)s_%(product_id)s' % {'vendor_id': pci_dev['vendor_id'], 'product_id': pci_dev['product_id']})
        pci_dev.update(dev_type=obj_fields.PciDeviceType.STANDARD, label=dev_label, numa_node=None)
    return jsonutils.dumps(pci_devices)
