webvirtcloud/vrtManager/instance.py

import time
import os.path
try:
    from libvirt import libvirtError, VIR_DOMAIN_XML_SECURE, VIR_DOMAIN_RUNNING, VIR_DOMAIN_AFFECT_LIVE, \
        VIR_DOMAIN_AFFECT_CONFIG, VIR_DOMAIN_UNDEFINE_NVRAM, VIR_DOMAIN_UNDEFINE_KEEP_NVRAM, VIR_DOMAIN_START_PAUSED
    from libvirt import VIR_MIGRATE_LIVE, \
        VIR_MIGRATE_UNSAFE, \
        VIR_MIGRATE_PERSIST_DEST, \
        VIR_MIGRATE_UNDEFINE_SOURCE, \
        VIR_MIGRATE_OFFLINE,\
        VIR_MIGRATE_COMPRESSED, \
        VIR_MIGRATE_AUTO_CONVERGE, \
        VIR_MIGRATE_POSTCOPY
    from libvirt import VIR_DOMAIN_INTERFACE_ADDRESSES_SRC_AGENT
except:
    from libvirt import libvirtError, VIR_DOMAIN_XML_SECURE, VIR_MIGRATE_LIVE

from vrtManager import util
from xml.etree import ElementTree
from lxml import etree
from datetime import datetime
from collections import OrderedDict
from vrtManager.connection import wvmConnect
from vrtManager.storage import wvmStorage, wvmStorages
from webvirtcloud.settings import QEMU_CONSOLE_TYPES
from webvirtcloud.settings import INSTANCE_VOLUME_DEFAULT_OWNER as OWNER


class wvmInstances(wvmConnect):
    def get_instance_status(self, name):
        inst = self.get_instance(name)
        return inst.info()[0]

    def get_instance_memory(self, name):
        inst = self.get_instance(name)
        mem = util.get_xml_path(inst.XMLDesc(0), "/domain/currentMemory")
        return int(mem) / 1024

    def get_instance_vcpu(self, name):
        inst = self.get_instance(name)
        cur_vcpu = util.get_xml_path(inst.XMLDesc(0), "/domain/vcpu/@current")
        if cur_vcpu:
            vcpu = cur_vcpu
        else:
            vcpu = util.get_xml_path(inst.XMLDesc(0), "/domain/vcpu")
        return vcpu

    def get_instance_managed_save_image(self, name):
        inst = self.get_instance(name)
        return inst.hasManagedSaveImage(0)

    def get_uuid(self, name):
        inst = self.get_instance(name)
        return inst.UUIDString()

    def start(self, name):
        dom = self.get_instance(name)
        dom.create()

    def shutdown(self, name):
        dom = self.get_instance(name)
        dom.shutdown()

    def force_shutdown(self, name):
        dom = self.get_instance(name)
        dom.destroy()

    def managedsave(self, name):
        dom = self.get_instance(name)
        dom.managedSave(0)

    def managed_save_remove(self, name):
        dom = self.get_instance(name)
        dom.managedSaveRemove(0)

    def suspend(self, name):
        dom = self.get_instance(name)
        dom.suspend()

    def resume(self, name):
        dom = self.get_instance(name)
        dom.resume()

    def moveto(self, conn, name, live, unsafe, undefine, offline, autoconverge=False, compress=False, postcopy=False):
        flags = VIR_MIGRATE_PERSIST_DEST
        if live and conn.get_status() != 5:
            flags |= VIR_MIGRATE_LIVE
        if unsafe and conn.get_status() == 1:
            flags |= VIR_MIGRATE_UNSAFE
        if offline and conn.get_status() == 5:
            flags |= VIR_MIGRATE_OFFLINE
        if not offline and autoconverge:
            flags |= VIR_MIGRATE_AUTO_CONVERGE
        if not offline and compress and conn.get_status() == 1:
            flags |= VIR_MIGRATE_COMPRESSED
        if not offline and postcopy and conn.get_status() == 1:
            flags |= VIR_MIGRATE_POSTCOPY
        if undefine:
            flags |= VIR_MIGRATE_UNDEFINE_SOURCE

        dom = conn.get_instance(name)

        dom_arch = conn.get_arch()
        dom_emulator = conn.get_dom_emulator()

        if dom_emulator != self.get_emulator(dom_arch):
            raise libvirtError('Destination host emulator is different. Cannot be migrated')

        dom.migrate(self.wvm, flags, None, None, 0)

    def graphics_type(self, name):
        inst = self.get_instance(name)
        console_type = util.get_xml_path(inst.XMLDesc(0), "/domain/devices/graphics/@type")
        if console_type is None:
            return "None"
        return console_type

    def graphics_listen(self, name):
        inst = self.get_instance(name)
        listen_addr = util.get_xml_path(inst.XMLDesc(0), "/domain/devices/graphics/@listen")
        if listen_addr is None:
            listen_addr = util.get_xml_path(inst.XMLDesc(0), "/domain/devices/graphics/listen/@address")
            if listen_addr is None:
                return "None"
        return listen_addr

    def graphics_port(self, name):
        inst = self.get_instance(name)
        console_port = util.get_xml_path(inst.XMLDesc(0), "/domain/devices/graphics/@port")
        if console_port is None:
            return "None"
        return console_port

    def domain_name(self, name):
        inst = self.get_instance(name)
        domname = util.get_xml_path(inst.XMLDesc(0), "/domain/name")
        if domname is None:
            return "NoName"
        return domname

    def graphics_passwd(self, name):
        inst = self.get_instance(name)
        password = util.get_xml_path(inst.XMLDesc(VIR_DOMAIN_XML_SECURE), "/domain/devices/graphics/@passwd")
        if password is None:
            return "None"
        return password


class wvmInstance(wvmConnect):
    def __init__(self, host, login, passwd, conn, vname):
        wvmConnect.__init__(self, host, login, passwd, conn)
        self._ip_cache = None
        self.instance = self.get_instance(vname)

    def start(self):
        self.instance.create()

    def shutdown(self):
        self.instance.shutdown()

    def force_shutdown(self):
        self.instance.destroy()

    def managedsave(self):
        self.instance.managedSave(0)

    def managed_save_remove(self):
        self.instance.managedSaveRemove(0)

    def suspend(self):
        self.instance.suspend()

    def resume(self):
        self.instance.resume()

    def delete(self, flags=0):
        self.instance.undefineFlags(flags)

    def _XMLDesc(self, flag):
        return self.instance.XMLDesc(flag)

    def _defineXML(self, xml):
        return self.wvm.defineXML(xml)

    def get_status(self):
        """
            VIR_DOMAIN_NOSTATE = 0
            VIR_DOMAIN_RUNNING = 1
            VIR_DOMAIN_PAUSED = 3
            VIR_DOMAIN_SHUTOFF = 5
        """
        return self.instance.info()[0]

    def get_autostart(self):
        return self.instance.autostart()

    def set_autostart(self, flag):
        return self.instance.setAutostart(flag)

    def get_uuid(self):
        return self.instance.UUIDString()

    def get_vcpu(self):
        vcpu = util.get_xml_path(self._XMLDesc(0), "/domain/vcpu")
        return int(vcpu)

    def get_cur_vcpu(self):
        cur_vcpu = util.get_xml_path(self._XMLDesc(0), "/domain/vcpu/@current")
        if cur_vcpu:
            return int(cur_vcpu)

    def get_arch(self):
        return util.get_xml_path(self._XMLDesc(0), "/domain/os/type/@arch")

    def get_machine_type(self):
        return util.get_xml_path(self._XMLDesc(0), "/domain/os/type/@machine")

    def get_dom_emulator(self):
        return util.get_xml_path(self._XMLDesc(0), "/domain/devices/emulator")

    def get_nvram(self):
        return util.get_xml_path(self._XMLDesc(0), "/domain/os/nvram")

    def get_loader(self):
        xml = self._XMLDesc(0)
        loader = util.get_xml_path(xml, "/domain/os/loader")
        type = util.get_xml_path(xml, "/domain/os/loader/@type")
        readonly = util.get_xml_path(xml, "/domain/os/loader/@readonly")
        return {"loader": loader, "type": type, "readonly": readonly}

    def get_vcpus(self):
        vcpus = OrderedDict()
        tree = etree.fromstring(self._XMLDesc(0))
        for vcpu in tree.xpath("/domain/vcpus/vcpu"):
            id = vcpu.get("id")
            enabled = vcpu.get("enabled")
            hotplug = vcpu.get("hotpluggable")
            order = vcpu.get("order")
            vcpus[id] = {"enabled": enabled, "hotpluggable": hotplug, "order": order}

        return vcpus

    def get_memory(self):
        mem = util.get_xml_path(self._XMLDesc(0), "/domain/memory")
        return int(mem) / 1024

    def get_cur_memory(self):
        mem = util.get_xml_path(self._XMLDesc(0), "/domain/currentMemory")
        return int(mem) / 1024

    def get_title(self):
        title = util.get_xml_path(self._XMLDesc(0), "/domain/title")
        return title if title else ''

    def get_filterrefs(self):

        def filterrefs(ctx):
            result = []
            for net in ctx.xpath('/domain/devices/interface'):
                filterref = net.xpath('filterref/@filter')
                if filterref:
                    result.append(filterref[0])
            return result

        return util.get_xml_path(self._XMLDesc(0), func=filterrefs)

    def get_description(self):
        description = util.get_xml_path(self._XMLDesc(0), "/domain/description")
        return description if description else ''

    def get_max_memory(self):
        return self.wvm.getInfo()[1] * 1048576

    def get_max_cpus(self):
        """Get number of physical CPUs."""
        hostinfo = self.wvm.getInfo()
        pcpus = hostinfo[4] * hostinfo[5] * hostinfo[6] * hostinfo[7]
        range_pcpus = xrange(1, int(pcpus + 1))
        return range_pcpus

    def get_interface_addresses(self, iface_mac):
        if self._ip_cache is None:
            self.refresh_interface_addresses()

        qemuga = self._ip_cache["qemuga"]
        arp = self._ip_cache["arp"]
        leases = []

        def extract_dom(info):
            ipv4 = None
            ipv6 = None
            for addrs in info.values():
                if addrs["hwaddr"] != iface_mac:
                    continue
                if not addrs["addrs"]:
                    continue
                for addr in addrs["addrs"]:
                    if addr["type"] == 0:
                        ipv4 = addr["addr"]
                    elif (addr["type"] == 1 and
                          not str(addr["addr"]).startswith("fe80")):
                        ipv6 = addr["addr"] + "/" + str(addr["prefix"])
            return ipv4, ipv6

        def extract_lease(info):
            ipv4 = None
            ipv6 = None
            if info["mac"] == iface_mac:
                if info["type"] == 0:
                    ipv4 = info["ipaddr"]
                elif info["type"] == 1:
                    ipv6 = info["ipaddr"]
            return ipv4, ipv6

        for ips in ([qemuga] + leases + [arp]):
            if "expirytime" in ips:
                ipv4, ipv6 = extract_lease(ips)
            else:
                ipv4, ipv6 = extract_dom(ips)
            if ipv4 or ipv6:
                return ipv4, ipv6
        return None, None

    def _get_interface_addresses(self, source):
        #("Calling interfaceAddresses source=%s", source)
        try:
            return self.instance.interfaceAddresses(source)
        except Exception as e:
            #log.debug("interfaceAddresses failed: %s", str(e))
            pass
        return {}

    def refresh_interface_addresses(self):
        self._ip_cache = {"qemuga": {}, "arp": {}}

        if not self.get_status() == 1:
            return

        if self.is_agent_ready():
            self._ip_cache["qemuga"] = self._get_interface_addresses(
                VIR_DOMAIN_INTERFACE_ADDRESSES_SRC_AGENT)

        arp_flag = 3 # libvirt."VIR_DOMAIN_INTERFACE_ADDRESSES_SRC_ARP"
        self._ip_cache["arp"] = self._get_interface_addresses(arp_flag)

    def get_net_devices(self):

        def networks(ctx):
            result = []
            inbound = outbound = []
            for net in ctx.xpath('/domain/devices/interface'):
                mac_inst = net.xpath('mac/@address')[0]
                nic_inst = net.xpath('source/@network|source/@bridge|source/@dev')[0]
                target_inst = '' if not net.xpath('target/@dev') else net.xpath('target/@dev')[0]
                link_state = 'up' if not net.xpath('link') else net.xpath('link/@state')[0]
                filterref_inst = '' if not net.xpath('filterref/@filter') else net.xpath('filterref/@filter')[0]
                if net.xpath('bandwidth/inbound'):
                    in_attr = net.xpath('bandwidth/inbound')[0]
                    in_av = in_attr.get('average')
                    in_peak = in_attr.get('peak')
                    in_burst = in_attr.get('burst')
                    inbound = {'average': in_av, 'peak': in_peak, 'burst': in_burst}
                if net.xpath('bandwidth/outbound'):
                    out_attr = net.xpath('bandwidth/outbound')[0]
                    out_av = out_attr.get('average')
                    out_peak = out_attr.get('peak')
                    out_burst = out_attr.get('burst')
                    outbound = {'average': out_av, 'peak': out_peak, 'burst': out_burst}

                try:
                    ipv4, ipv6 = self.get_interface_addresses(mac_inst)
                except:
                    ipv4, ipv6 = None, None
                result.append({'mac': mac_inst,
                               'nic': nic_inst,
                               'target': target_inst,
                               'state': link_state,
                               'ipv4': ipv4,
                               'ipv6': ipv6,
                               'filterref': filterref_inst,
                               'inbound': inbound,
                               'outbound': outbound,
                               })
            return result

        return util.get_xml_path(self._XMLDesc(0), func=networks)

    def get_disk_devices(self):
        def disks(doc):
            result = []
            dev = volume = storage = src_file = bus = None
            disk_format = used_size = disk_size = disk_cache = None
            
            for disk in doc.xpath('/domain/devices/disk'):
                device = disk.xpath('@device')[0]
                if device == 'disk':
                    try:
                        dev = disk.xpath('target/@dev')[0]
                        bus = disk.xpath('target/@bus')[0]
                        src_file = disk.xpath('source/@file|source/@dev|source/@name|source/@volume')[0]
                        try:
                            disk_format = disk.xpath('driver/@type')[0]
                        except:
                            pass
                        try:
                            disk_cache = disk.xpath('driver/@cache')[0]
                        except:
                            pass
                        try:
                            vol = self.get_volume_by_path(src_file)
                            volume = vol.name()

                            disk_size = vol.info()[1]
                            used_size = vol.info()[2]
                            stg = vol.storagePoolLookupByVolume()
                            storage = stg.name()
                        except libvirtError:
                            volume = src_file
                    except:
                        pass
                    finally:
                        result.append(
                            {'dev': dev, 'bus': bus, 'image': volume, 'storage': storage, 'path': src_file,
                             'format': disk_format, 'size': disk_size, 'used': used_size, 'cache': disk_cache})
            return result

        return util.get_xml_path(self._XMLDesc(0), func=disks)

    def get_media_devices(self):
        def disks(doc):
            result = []
            dev = volume = storage = bus = None
            src_file = None
            for media in doc.xpath('/domain/devices/disk'):
                device = media.xpath('@device')[0]
                if device == 'cdrom':
                    try:
                        dev = media.xpath('target/@dev')[0]
                        bus = media.xpath('target/@bus')[0]
                        try:
                            src_file = media.xpath('source/@file')[0]
                            vol = self.get_volume_by_path(src_file)
                            volume = vol.name()
                            stg = vol.storagePoolLookupByVolume()
                            storage = stg.name()
                        except:
                            src_file = None
                            volume = src_file
                    except:
                        pass
                    finally:
                        result.append({'dev': dev, 'image': volume, 'storage': storage, 'path': src_file, 'bus': bus})
            return result

        return util.get_xml_path(self._XMLDesc(0), func=disks)

    def get_bootmenu(self):
        menu = util.get_xml_path(self._XMLDesc(0), "/domain/os/bootmenu/@enable")
        return True if menu == 'yes' else False

    def set_bootmenu(self, flag):
        tree = ElementTree.fromstring(self._XMLDesc(0))
        os = tree.find('os')
        menu = os.find("bootmenu")

        if menu is None:
            bootmenu = ElementTree.fromstring("<bootmenu enable='yes'/>")
            os.append(bootmenu)
            menu = os.find("bootmenu")

        if flag == 0:  # Disable
            menu.attrib['enable'] = 'no'
        elif flag == 1:  # Enable
            menu.attrib['enable'] = 'yes'
        elif flag == -1:  # Remove
            os.remove(menu)
        else:
            raise Exception('Unknown boot menu option, please choose one of 0:disable, 1:enable, -1:remove')

        xmldom = ElementTree.tostring(tree)
        self._defineXML(xmldom)

    def get_bootorder(self):
        boot_order = {}
        type = target = None
        tree = ElementTree.fromstring(self._XMLDesc(0))
        os = tree.find('os')
        boot = os.findall('boot')

        for idx, b in enumerate(boot):
            dev = b.get('dev')
            if dev == 'hd':
                target = "disk"
                type = "file"
            elif dev == 'fd':
                target = "floppy"
                type = "file"
            elif dev == 'cdrom':
                target = "cdrom"
                type = "file"
            elif dev == 'network':
                target = "network"
                type = "network"
            boot_order[idx] = {"type": type, "dev": dev, "target": target}

        devices = tree.find('devices')
        for dev in devices:
            dev_target = None
            boot_dev = dev.find('boot')
            if boot_dev is not None:
                idx = boot_dev.get('order')
                dev_type = dev.get('type')
                dev_device = dev.get('device')

                if dev_type == 'file':
                    dev_target = dev.find('target').get('dev')

                elif dev_type == 'network':
                    dev_mac = dev.find('mac').get('address')
                    dev_device = "network"
                    dev_target = "nic-{}".format(dev_mac[9:])
                elif dev_type == 'usb':
                    pass

                boot_order[int(idx)-1] = {"type": dev_type, "dev": dev_device, "target": dev_target}

        return boot_order

    def set_bootorder(self, devorder):
        if not devorder:
            return

        def remove_bootorder():
            tree = ElementTree.fromstring(self._XMLDesc(0))
            os = tree.find('os')
            boot = os.findall('boot')
            # Remove old style boot order
            for b in boot:
                os.remove(b)
            # Remove rest of them
            for dev in tree.find('devices'):
                boot_dev = dev.find('boot')
                if boot_dev is not None:
                    dev.remove(boot_dev)
            return tree

        tree = remove_bootorder()

        for idx, dev in devorder.items():
            order = ElementTree.fromstring("<boot order='{}'/>".format(idx + 1))
            if dev['type'] == 'disk':
                devices = tree.findall("./devices/disk[@device='disk']")
                for d in devices:
                    device = d.find("./target[@dev='{}']".format(dev['dev']))
                    if device is not None:
                        d.append(order)
            elif dev['type'] == 'cdrom':
                devices = tree.findall("./devices/disk[@device='cdrom']")
                for d in devices:
                    device = d.find("./target[@dev='{}']".format(dev['dev']))
                    if device is not None:
                        d.append(order)
            elif dev['type'] == 'network':
                devices = tree.findall("./devices/interface[@type='network']")
                for d in devices:
                    device = d.find("mac[@address='{}']".format(dev['dev']))
                    if device is not None:
                        d.append(order)
            else:
                raise Exception('Invalid Device Type for boot order')
        self._defineXML(ElementTree.tostring(tree))

    def mount_iso(self, dev, image):
        def attach_iso(dev, disk, vol):
            if disk.get('device') == 'cdrom':
                for elm in disk:
                    if elm.tag == 'target':
                        if elm.get('dev') == dev:
                            src_media = ElementTree.Element('source')
                            src_media.set('file', vol.path())
                            disk.insert(2, src_media)
                            return True

        vol = None
        storages = self.get_storages(only_actives=True)
        for storage in storages:
            stg = self.get_storage(storage)
            if stg.info()[0] != 0:
                for img in stg.listVolumes():
                    if image == img:
                        vol = stg.storageVolLookupByName(image)
        tree = ElementTree.fromstring(self._XMLDesc(0))
        for disk in tree.findall('devices/disk'):
            if attach_iso(dev, disk, vol):
                break
        if self.get_status() == 1:
            xml = ElementTree.tostring(disk)
            self.instance.attachDevice(xml)
            xmldom = self._XMLDesc(VIR_DOMAIN_XML_SECURE)
        if self.get_status() == 5:
            xmldom = ElementTree.tostring(tree)
        self._defineXML(xmldom)

    def umount_iso(self, dev, image):
        tree = ElementTree.fromstring(self._XMLDesc(0))
        for disk in tree.findall('devices/disk'):
            if disk.get('device') == 'cdrom':
                for elm in disk:
                    if elm.tag == 'source':
                        if elm.get('file') == image:
                            src_media = elm
                    if elm.tag == 'target':
                        if elm.get('dev') == dev:
                            disk.remove(src_media)
        if self.get_status() == 1:
            xml_disk = ElementTree.tostring(disk)
            self.instance.attachDevice(xml_disk)
            xmldom = self._XMLDesc(VIR_DOMAIN_XML_SECURE)
        if self.get_status() == 5:
            xmldom = ElementTree.tostring(tree)
        self._defineXML(xmldom)

    def attach_disk(self, source, target, sourcetype='file', device='disk', driver='qemu', subdriver='raw', cache='none', targetbus='ide'):
        xml_disk = "<disk type='%s' device='%s'>" % (sourcetype, device)
        if device == 'cdrom':
            xml_disk += "<driver name='%s' type='%s'/>" % (driver, subdriver)
        elif device == 'disk':
            xml_disk += "<driver name='%s' type='%s' cache='%s'/>" % (driver, subdriver, cache)
        xml_disk += """<source file='%s'/>
          <target dev='%s' bus='%s'/>
        </disk>
        """ % (source, target, targetbus)
        if self.get_status() == 1:
            self.instance.attachDeviceFlags(xml_disk, VIR_DOMAIN_AFFECT_LIVE)
            self.instance.attachDeviceFlags(xml_disk, VIR_DOMAIN_AFFECT_CONFIG)
        if self.get_status() == 5:
            self.instance.attachDeviceFlags(xml_disk, VIR_DOMAIN_AFFECT_CONFIG)

    def detach_disk(self, dev):
        tree = ElementTree.fromstring(self._XMLDesc(0))

        for disk in tree.findall("./devices/disk"):
            target = disk.find("target")
            if target.get("dev") == dev:
                devices = tree.find('devices')
                devices.remove(disk)

                if self.get_status() == 1:
                    xml_disk = ElementTree.tostring(disk)
                    ret = self.instance.detachDevice(xml_disk)
                    xmldom = self._XMLDesc(VIR_DOMAIN_XML_SECURE)
                if self.get_status() == 5:
                    xmldom = ElementTree.tostring(tree)
                break
        self._defineXML(xmldom)

    def cpu_usage(self):
        cpu_usage = {}
        if self.get_status() == 1:
            nbcore = self.wvm.getInfo()[2]
            cpu_use_ago = self.instance.info()[4]
            time.sleep(1)
            cpu_use_now = self.instance.info()[4]
            diff_usage = cpu_use_now - cpu_use_ago
            cpu_usage['cpu'] = 100 * diff_usage / (1 * nbcore * 10 ** 9L)
        else:
            cpu_usage['cpu'] = 0
        return cpu_usage

    def set_vcpu(self, cpu_id, enabled):
        self.instance.setVcpu(str(cpu_id), enabled)

    def set_vcpu_hotplug(self, status, vcpus_hotplug=0):
        """ vcpus_hotplug = 0 make all vpus hotpluggable """
        vcpus_hotplug = int(self.get_vcpu()) if vcpus_hotplug == 0 else vcpus_hotplug
        if self.get_status() == 5: # shutoff
            if status:
                xml = """ <vcpus>"""
                xml += """<vcpu id='0' enabled='yes' hotpluggable='no' order='1'/>"""
                for i in range(1, vcpus_hotplug):
                    xml += """<vcpu id='{}' enabled='yes' hotpluggable='yes' order='{}'/>""".format(i, i+1)
                xml += """</vcpus>"""

                tree = etree.fromstring(self._XMLDesc(0))
                vcpus = tree.xpath("/domain/vcpus")
                if not vcpus:
                    tree.append(etree.fromstring(xml))
                    self._defineXML(etree.tostring(tree))
            else:
                tree = etree.fromstring(self._XMLDesc(0))
                vcpus = tree.xpath("/domain/vcpus")
                for vcpu in vcpus:
                    parent = vcpu.getparent()
                    parent.remove(vcpu)
                    self._defineXML(etree.tostring(tree))
        else:
            raise libvirtError("Please shutdown the instance then try to enable vCPU hotplug")

    def mem_usage(self):
        mem_usage = {}
        if self.get_status() == 1:
            mem_stats = self.instance.memoryStats()
            rss = mem_stats['rss'] if 'rss' in mem_stats else 0
            total = mem_stats['actual'] if 'actual' in mem_stats else 0
            available = total - rss
            if available < 0: available = 0

            mem_usage['used'] = rss
            mem_usage['total'] = total
        else:
            mem_usage['used'] = 0
            mem_usage['total'] = 0
        return mem_usage

    def disk_usage(self):
        devices = []
        dev_usage = []
        tree = ElementTree.fromstring(self._XMLDesc(0))
        for disk in tree.findall('devices/disk'):
            if disk.get('device') == 'disk':
                dev_file = None
                dev_bus = None
                network_disk = True
                for elm in disk:
                    if elm.tag == 'source':
                        if elm.get('protocol'):
                            dev_file = elm.get('protocol')
                            network_disk = True
                        if elm.get('file'):
                            dev_file = elm.get('file')
                        if elm.get('dev'):
                            dev_file = elm.get('dev')
                    if elm.tag == 'target':
                        dev_bus = elm.get('dev')
                if (dev_file and dev_bus) is not None:
                    if network_disk:
                        dev_file = dev_bus
                    devices.append([dev_file, dev_bus])
        for dev in devices:
            if self.get_status() == 1:
                rd_use_ago = self.instance.blockStats(dev[0])[1]
                wr_use_ago = self.instance.blockStats(dev[0])[3]
                time.sleep(1)
                rd_use_now = self.instance.blockStats(dev[0])[1]
                wr_use_now = self.instance.blockStats(dev[0])[3]
                rd_diff_usage = rd_use_now - rd_use_ago
                wr_diff_usage = wr_use_now - wr_use_ago
            else:
                rd_diff_usage = 0
                wr_diff_usage = 0
            dev_usage.append({'dev': dev[1], 'rd': rd_diff_usage, 'wr': wr_diff_usage})
        return dev_usage

    def net_usage(self):
        devices = []
        dev_usage = []
        if self.get_status() == 1:
            tree = ElementTree.fromstring(self._XMLDesc(0))
            for target in tree.findall("devices/interface/target"):
                devices.append(target.get("dev"))
            for i, dev in enumerate(devices):
                rx_use_ago = self.instance.interfaceStats(dev)[0]
                tx_use_ago = self.instance.interfaceStats(dev)[4]
                time.sleep(1)
                rx_use_now = self.instance.interfaceStats(dev)[0]
                tx_use_now = self.instance.interfaceStats(dev)[4]
                rx_diff_usage = (rx_use_now - rx_use_ago) * 8
                tx_diff_usage = (tx_use_now - tx_use_ago) * 8
                dev_usage.append({'dev': i, 'rx': rx_diff_usage, 'tx': tx_diff_usage})
        else:
            for i, dev in enumerate(self.get_net_devices()):
                dev_usage.append({'dev': i, 'rx': 0, 'tx': 0})
        return dev_usage

    def get_telnet_port(self):
        telnet_port = None
        service_port = None
        tree = ElementTree.fromstring(self._XMLDesc(0))
        for console in tree.findall('devices/console'):
            if console.get('type') == 'tcp':
                for elm in console:
                    if elm.tag == 'source':
                        if elm.get('service'):
                            service_port = elm.get('service')
                    if elm.tag == 'protocol':
                        if elm.get('type') == 'telnet':
                            if service_port is not None:
                                telnet_port = service_port
        return telnet_port

    def get_console_listen_addr(self):
        listen_addr = util.get_xml_path(self._XMLDesc(0), "/domain/devices/graphics/@listen")
        if listen_addr is None:
            listen_addr = util.get_xml_path(self._XMLDesc(0), "/domain/devices/graphics/listen/@address")
            if listen_addr is None:
                return "127.0.0.1"
        return listen_addr

    def set_console_listen_addr(self, listen_addr):
        xml = self._XMLDesc(VIR_DOMAIN_XML_SECURE)
        root = ElementTree.fromstring(xml)
        console_type = self.get_console_type()
        try:
            graphic = root.find("devices/graphics[@type='%s']" % console_type)
        except SyntaxError:
            # Little fix for old version ElementTree
            graphic = root.find("devices/graphics")
        if graphic is None:
            return False
        listen = graphic.find("listen[@type='address']")
        if listen is None:
            return False
        if listen_addr:
            graphic.set("listen", listen_addr)
            listen.set("address", listen_addr)
        else:
            try:
                graphic.attrib.pop("listen")
                listen.attrib.pop("address")
            except:
                pass
        newxml = ElementTree.tostring(root)
        return self._defineXML(newxml)
    
    def get_console_socket(self):
        socket = util.get_xml_path(self._XMLDesc(0), "/domain/devices/graphics/@socket")
        return socket

    def get_console_type(self):
        console_type = util.get_xml_path(self._XMLDesc(0), "/domain/devices/graphics/@type")
        return console_type

    def set_console_type(self, console_type):
        current_type = self.get_console_type()
        if current_type == console_type:
            return True
        if console_type == '' or console_type not in QEMU_CONSOLE_TYPES:
            return False
        xml = self._XMLDesc(VIR_DOMAIN_XML_SECURE)
        root = ElementTree.fromstring(xml)
        try:
            graphic = root.find("devices/graphics[@type='%s']" % current_type)
        except SyntaxError:
            # Little fix for old version ElementTree
            graphic = root.find("devices/graphics")
        graphic.set('type', console_type)
        newxml = ElementTree.tostring(root)
        self._defineXML(newxml)

    def get_console_port(self, console_type=None):
        if console_type is None:
            console_type = self.get_console_type()
        port = util.get_xml_path(self._XMLDesc(0), "/domain/devices/graphics[@type='%s']/@port" % console_type)
        return port

    def get_console_websocket_port(self):
        console_type = self.get_console_type()
        websocket_port = util.get_xml_path(self._XMLDesc(0),
                                           "/domain/devices/graphics[@type='%s']/@websocket" % console_type)
        return websocket_port

    def get_console_passwd(self):
        return util.get_xml_path(self._XMLDesc(VIR_DOMAIN_XML_SECURE), "/domain/devices/graphics/@passwd")

    def set_console_passwd(self, passwd):
        xml = self._XMLDesc(VIR_DOMAIN_XML_SECURE)
        root = ElementTree.fromstring(xml)
        console_type = self.get_console_type()
        try:
            graphic = root.find("devices/graphics[@type='%s']" % console_type)
        except SyntaxError:
            # Little fix for old version ElementTree
            graphic = root.find("devices/graphics")
        if graphic is None:
            return False
        if passwd:
            graphic.set('passwd', passwd)
        else:
            try:
                graphic.attrib.pop('passwd')
            except:
                pass
        newxml = ElementTree.tostring(root)
        return self._defineXML(newxml)

    def set_console_keymap(self, keymap):
        xml = self._XMLDesc(VIR_DOMAIN_XML_SECURE)
        root = ElementTree.fromstring(xml)
        console_type = self.get_console_type()
        try:
            graphic = root.find("devices/graphics[@type='%s']" % console_type)
        except SyntaxError:
            # Little fix for old version ElementTree
            graphic = root.find("devices/graphics")
        if keymap:
            graphic.set('keymap', keymap)
        else:
            try:
                graphic.attrib.pop('keymap')
            except:
                pass
        newxml = ElementTree.tostring(root)
        self._defineXML(newxml)

    def get_console_keymap(self):
        return util.get_xml_path(self._XMLDesc(VIR_DOMAIN_XML_SECURE), "/domain/devices/graphics/@keymap") or ''

    def get_video_model(self):
        """ :return only primary video card"""
        xml = self._XMLDesc(VIR_DOMAIN_XML_SECURE)
        tree = etree.fromstring(xml)
        video_models = tree.xpath("/domain/devices/video/model")
        for model in video_models:
            if model.get('primary') == 'yes' or len(video_models) == 1:
                return model.get('type')

    def set_video_model(self, model):
        """ Changes only primary video card"""
        xml = self._XMLDesc(VIR_DOMAIN_XML_SECURE)
        tree = etree.fromstring(xml)
        video_models = tree.xpath("/domain/devices/video/model")
        video_xml = "<model type='{}'/>".format(model)
        for model in video_models:
            if model.get('primary') == 'yes' or len(video_models) == 1:
                parent = model.getparent()
                parent.remove(model)
                parent.append(etree.fromstring(video_xml))
                self._defineXML(etree.tostring(tree))

    def resize_cpu(self, cur_vcpu, vcpu):
        """
        Function change ram and cpu on instance.
        """
        is_vcpus_enabled = self.get_vcpus()
        if is_vcpus_enabled:
            self.set_vcpu_hotplug(False)

        xml = self._XMLDesc(VIR_DOMAIN_XML_SECURE)
        tree = etree.fromstring(xml)

        set_vcpu = tree.find('vcpu')
        set_vcpu.text = vcpu
        set_vcpu.set('current', cur_vcpu)

        new_xml = etree.tostring(tree)
        self._defineXML(new_xml)

        if is_vcpus_enabled:
            self.set_vcpu_hotplug(True, int(cur_vcpu))

    def resize_mem(self, cur_memory, memory):
        """
        Function change ram and cpu on vds.
        """
        memory = int(memory) * 1024
        cur_memory = int(cur_memory) * 1024
        # if dom is running change only ram
        if self.get_status() == VIR_DOMAIN_RUNNING:
            self.set_memory(cur_memory, VIR_DOMAIN_AFFECT_LIVE)
            self.set_memory(cur_memory, VIR_DOMAIN_AFFECT_CONFIG)
            return

        xml = self._XMLDesc(VIR_DOMAIN_XML_SECURE)
        tree = ElementTree.fromstring(xml)

        set_mem = tree.find('memory')
        set_mem.text = str(memory)
        set_cur_mem = tree.find('currentMemory')
        set_cur_mem.text = str(cur_memory)

        new_xml = ElementTree.tostring(tree)
        self._defineXML(new_xml)

    def resize_disk(self, disks):
        """
        Function change disks on vds.
        """
        xml = self._XMLDesc(VIR_DOMAIN_XML_SECURE)
        tree = ElementTree.fromstring(xml)

        for disk in disks:
            source_dev = disk['path']
            vol = self.get_volume_by_path(source_dev)
            vol.resize(disk['size_new'])

        new_xml = ElementTree.tostring(tree)
        self._defineXML(new_xml)

    def get_iso_media(self):
        iso = []
        storages = self.get_storages(only_actives=True)
        for storage in storages:
            stg = self.get_storage(storage)
            if stg.info()[0] != 0:
                try:
                    stg.refresh(0)
                except:
                    pass
                for img in stg.listVolumes():
                    if img.lower().endswith('.iso'):
                        iso.append(img)
        return iso

    def delete_all_disks(self):
        disks = self.get_disk_devices()
        for disk in disks:
            vol = self.get_volume_by_path(disk.get('path'))
            vol.delete(0)

    def _snapshotCreateXML(self, xml, flag):
        self.instance.snapshotCreateXML(xml, flag)

    def create_snapshot(self, name):
        xml = """<domainsnapshot>
                     <name>%s</name>
                     <state>shutoff</state>
                     <creationTime>%d</creationTime>""" % (name, time.time())
        xml += self._XMLDesc(VIR_DOMAIN_XML_SECURE)
        xml += """<active>0</active>
                  </domainsnapshot>"""
        self._snapshotCreateXML(xml, 0)

    def get_snapshot(self):
        snapshots = []
        snapshot_list = self.instance.snapshotListNames(0)
        for snapshot in snapshot_list:
            snap = self.instance.snapshotLookupByName(snapshot, 0)
            snap_time_create = util.get_xml_path(snap.getXMLDesc(0), "/domainsnapshot/creationTime")
            snapshots.append({'date': datetime.fromtimestamp(int(snap_time_create)), 'name': snapshot})
        return snapshots

    def snapshot_delete(self, snapshot):
        snap = self.instance.snapshotLookupByName(snapshot, 0)
        snap.delete(0)

    def snapshot_revert(self, snapshot):
        snap = self.instance.snapshotLookupByName(snapshot, 0)
        self.instance.revertToSnapshot(snap, 0)

    def get_managed_save_image(self):
        return self.instance.hasManagedSaveImage(0)

    def get_wvmStorage(self, pool):
        return wvmStorage(self.host, self.login, self.passwd, self.conn, pool)

    def get_wvmStorages(self):
        return wvmStorages(self.host, self.login, self.passwd, self.conn)

    def fix_mac(self, mac):
        if ":" in mac:
            return mac
        # if mac does not contain ":", try to split into tuples and join with ":"
        n = 2
        mac_tuples = [mac[i:i+n] for i in range(0, len(mac), n)]
        return ':'.join(mac_tuples)

    def clone_instance(self, clone_data):
        clone_dev_path = []

        xml = self._XMLDesc(VIR_DOMAIN_XML_SECURE)
        tree = etree.fromstring(xml)
        name = tree.find('name')
        name.text = clone_data['name']
        uuid = tree.find('uuid')
        tree.remove(uuid)

        src_nvram_path = self.get_nvram()
        if src_nvram_path:
            # Change XML for nvram
            nvram = tree.find('os/nvram')
            nvram.getparent().remove(nvram)

            # NVRAM CLONE: create pool if nvram is not in a pool. then clone it
            src_nvram_name = os.path.basename(src_nvram_path)
            nvram_dir = os.path.dirname(src_nvram_path)
            nvram_pool_name = os.path.basename(nvram_dir)
            try:
                self.get_volume_by_path(src_nvram_path)
            except libvirtError:
                stg_conn = self.get_wvmStorages()
                stg_conn.create_storage('dir', nvram_pool_name, None, nvram_dir)

            new_nvram_name = "%s_VARS" % clone_data['name']
            nvram_stg = self.get_wvmStorage(nvram_pool_name)
            nvram_stg.clone_volume(src_nvram_name, new_nvram_name, file_suffix='fd')

        for num, net in enumerate(tree.findall('devices/interface')):
            elm = net.find('mac')
            mac_address = self.fix_mac(clone_data['clone-net-mac-' + str(num)])
            elm.set('address', mac_address)

        for disk in tree.findall('devices/disk'):
            if disk.get('device') == 'disk':
                elm = disk.find('target')
                device_name = elm.get('dev')
                if device_name:
                    target_file = clone_data['disk-' + device_name]
                    try:
                        meta_prealloc = clone_data['meta-' + device_name]
                    except:
                        meta_prealloc = False
                    elm.set('dev', device_name)

                elm = disk.find('source')
                source_file = elm.get('file')
                if source_file:
                    clone_dev_path.append(source_file)
                    clone_path = os.path.join(os.path.dirname(source_file), target_file)
                    elm.set('file', clone_path)

                    vol = self.get_volume_by_path(source_file)
                    vol_format = util.get_xml_path(vol.XMLDesc(0), "/volume/target/format/@type")

                    if vol_format == 'qcow2' and meta_prealloc:
                        meta_prealloc = True

                    vol_clone_xml = """
                                    <volume>
                                        <name>%s</name>
                                        <capacity>0</capacity>
                                        <allocation>0</allocation>
                                        <target>
                                            <format type='%s'/>
                                            <permissions>
                                                <owner>%s</owner>
                                                <group>%s</group>
                                                <mode>0644</mode>
                                                <label>virt_image_t</label>
                                            </permissions>
                                            <compat>1.1</compat>
                                            <features>
                                                <lazy_refcounts/>
                                            </features>
                                        </target>
                                    </volume>""" % (target_file, vol_format, OWNER['uid'], OWNER['guid'])

                    stg = vol.storagePoolLookupByVolume()
                    stg.createXMLFrom(vol_clone_xml, vol, meta_prealloc)
                
                source_protocol = elm.get('protocol')
                if source_protocol == 'rbd':
                    source_name = elm.get('name')
                    clone_name = "%s/%s" % (os.path.dirname(source_name), target_file)
                    elm.set('name', clone_name)

                    vol = self.get_volume_by_path(source_name)
                    vol_format = util.get_xml_path(vol.XMLDesc(0), "/volume/target/format/@type")

                    vol_clone_xml = """
                                    <volume type='network'>
                                        <name>%s</name>
                                        <capacity>0</capacity>
                                        <allocation>0</allocation>
                                        <target>
                                            <format type='%s'/>
                                        </target>
                                    </volume>""" % (target_file, vol_format)
                    stg = vol.storagePoolLookupByVolume()
                    stg.createXMLFrom(vol_clone_xml, vol, meta_prealloc)

                source_dev = elm.get('dev')
                if source_dev:
                    clone_path = os.path.join(os.path.dirname(source_dev), target_file)
                    elm.set('dev', clone_path)
                    
                    vol = self.get_volume_by_path(source_dev)
                    stg = vol.storagePoolLookupByVolume()
                    
                    vol_name = util.get_xml_path(vol.XMLDesc(0), "/volume/name")
                    pool_name = util.get_xml_path(stg.XMLDesc(0), "/pool/name")
                    
                    storage = self.get_wvmStorage(pool_name)
                    storage.clone_volume(vol_name, target_file)

        options = {
            'title': clone_data.get('clone-title', ''),
            'description': clone_data.get('clone-description', ''),
        }
        self._set_options(tree, options)
        self._defineXML(ElementTree.tostring(tree))

        return self.get_instance(clone_data['name']).UUIDString()

    def get_bridge_name(self, source, source_type='net'):
        if source_type == 'iface':
            iface = self.get_iface(source)
            bridge_name = iface.name()
        else:
            net = self.get_network(source)
            bridge_name = net.bridgeName()
        return bridge_name
        
    def add_network(self, mac_address, source, source_type='net', model='virtio', nwfilter=None):
        bridge_name = self.get_bridge_name(source, source_type)

        forward_mode = self.get_network_forward(source)
        if forward_mode in ['nat', 'isolated', 'routed']:
            interface_type = 'network'
        else:
            interface_type = 'bridge'

        xml_iface = """
          <interface type='%s'>
          <mac address='%s'/>""" % (interface_type, mac_address)
        if interface_type == 'network':
            xml_iface += """<source network='%s'/>""" % source
        else:
            xml_iface += """<source bridge='%s'/>""" % bridge_name
        xml_iface += """<model type='%s'/>""" % model
        if nwfilter:
            xml_iface += """
            <filterref filter='%s'/>
            """ % nwfilter
        xml_iface += """</interface>"""

        if self.get_status() == 1:
            self.instance.attachDeviceFlags(xml_iface, VIR_DOMAIN_AFFECT_LIVE)
            self.instance.attachDeviceFlags(xml_iface, VIR_DOMAIN_AFFECT_CONFIG)
        if self.get_status() == 5:
            self.instance.attachDeviceFlags(xml_iface, VIR_DOMAIN_AFFECT_CONFIG)

    def delete_network(self, mac_address):
        tree = ElementTree.fromstring(self._XMLDesc(0))
        for interface in tree.findall('devices/interface'):
            source = interface.find('mac')
            if source.get('address', '') == mac_address:
                new_xml = ElementTree.tostring(interface)

                if self.get_status() == 1:
                    self.instance.detachDeviceFlags(new_xml, VIR_DOMAIN_AFFECT_LIVE)
                    self.instance.detachDeviceFlags(new_xml, VIR_DOMAIN_AFFECT_CONFIG)
                if self.get_status() == 5:
                    self.instance.detachDeviceFlags(new_xml, VIR_DOMAIN_AFFECT_CONFIG)

    def change_network(self, network_data):
        xml = self._XMLDesc(VIR_DOMAIN_XML_SECURE)
        tree = ElementTree.fromstring(xml)
        for num, interface in enumerate(tree.findall('devices/interface')):
            net_mac = network_data.get('net-mac-' + str(num))
            if net_mac is None: continue
            net_source = network_data.get('net-source-' + str(num))
            net_source_type = network_data.get('net-source-' + str(num) + '-type')
            net_filter = network_data.get('net-nwfilter-' + str(num))
            bridge_name = self.get_bridge_name(net_source, net_source_type)
            if interface.get('type') == 'bridge':
                source = interface.find('mac')
                source.set('address', net_mac)
                source = interface.find('source')
                source.set('bridge', bridge_name)
                source = interface.find('filterref')

                if net_filter:
                    if source is not None: source.set('filter', net_filter)
                    else:
                        element = ElementTree.Element("filterref")
                        element.attrib['filter'] = net_filter
                        interface.append(element)
                else:
                    if source is not None: interface.remove(source)
            elif interface.get('type') == 'network':
                source = interface.find('mac')
                source.set('address', net_mac)
                source = interface.find('source')
                source.set('network', net_source)
                source = interface.find('filterref')

                if net_filter:
                    if source is not None: source.set('filter', net_filter)
                    else:
                        element = ElementTree.Element("filterref")
                        element.attrib['filter'] = net_filter
                        interface.append(element)
                else:
                    if source is not None: interface.remove(source)

        new_xml = ElementTree.tostring(tree)
        self._defineXML(new_xml)

    def set_link_state(self, mac_address, state):
        tree = etree.fromstring(self._XMLDesc(0))
        for interface in tree.findall('devices/interface'):
            source = interface.find('mac')
            if source.get('address') == mac_address:
                link = interface.find('link')
                if link is not None:
                    interface.remove(link)
                link_el = etree.Element("link")
                link_el.attrib["state"] = state
                interface.append(link_el)
                new_xml = etree.tostring(interface)
                if self.get_status() == 1:
                    self.instance.updateDeviceFlags(new_xml, VIR_DOMAIN_AFFECT_LIVE)
                    self.instance.updateDeviceFlags(new_xml, VIR_DOMAIN_AFFECT_CONFIG)
                if self.get_status() == 5:
                    self.instance.updateDeviceFlags(new_xml, VIR_DOMAIN_AFFECT_CONFIG)

    def _set_options(self, tree, options):
        for o in ['title', 'description']:
            option = tree.find(o)
            option_value = options.get(o, '').strip()
            if not option_value:
                if option is not None:
                    tree.remove(option)
            else:
                if option is None:
                    option = ElementTree.SubElement(tree, o)
                option.text = option_value

    def set_options(self, options):
        """
        Function change description, title
        """
        xml = self._XMLDesc(VIR_DOMAIN_XML_SECURE)
        tree = ElementTree.fromstring(xml)

        self._set_options(tree, options)
        new_xml = ElementTree.tostring(tree)
        self._defineXML(new_xml)

    def set_memory(self, size, flags=0):
        self.instance.setMemoryFlags(size, flags)

    def get_all_qos(self):
        qos_values = dict()
        tree = etree.fromstring(self._XMLDesc(0))
        qos = tree.xpath("/domain/devices/interface")

        for q in qos:
            bound_list = list()
            mac = q.xpath('mac/@address')
            band = q.find('bandwidth')
            if band is not None:
                in_qos = band.find('inbound')
                if in_qos is not None:
                    in_av = in_qos.get('average')
                    in_peak = in_qos.get('peak')
                    in_burst = in_qos.get('burst')
                    in_floor = in_qos.get('floor')
                    bound_list.append({'direction': 'inbound', 'average': in_av, 'peak': in_peak, 'floor': in_floor, 'burst': in_burst})

                out_qos = band.find('outbound')
                if out_qos is not None:
                    out_av = out_qos.get('average')
                    out_peak = out_qos.get('peak')
                    out_burst = out_qos.get('burst')
                    bound_list.append({'direction': 'outbound', 'average': out_av, 'peak': out_peak, 'burst': out_burst})
                qos_values[mac[0]] = bound_list
        return qos_values

    def set_qos(self, mac, direction, average, peak, burst):
        if direction == "inbound":
            xml = "<inbound average='{}' peak='{}' burst='{}'/>".format(average, peak, burst)
        elif direction == "outbound":
            xml = "<outbound average='{}' peak='{}' burst='{}'/>".format(average, peak, burst)
        else:
            raise Exception('Direction must be inbound or outbound')

        tree = etree.fromstring(self._XMLDesc(0))

        macs = tree.xpath("/domain/devices/interface/mac")
        for cur_mac in macs:

            if cur_mac.get("address") == mac:
                interface = cur_mac.getparent()
                band = interface.find('bandwidth')
                if band is None:
                    xml = "<bandwidth>" + xml + "</bandwidth>"
                    interface.append(etree.fromstring(xml))
                else:
                    direct = band.find(direction)
                    if direct is not None:
                        parent = direct.getparent()
                        parent.remove(direct)
                        parent.append(etree.fromstring(xml))
                    else:
                        band.append(etree.fromstring(xml))
        new_xml = etree.tostring(tree)
        self.wvm.defineXML(new_xml)

    def unset_qos(self, mac, direction):
        tree = etree.fromstring(self._XMLDesc(0))
        for direct in tree.xpath("/domain/devices/interface/bandwidth/{}".format(direction)):
            band_el = direct.getparent()
            interface_el = band_el.getparent()  # parent bandwidth,its parent is interface
            parent_mac = interface_el.xpath('mac/@address')
            if parent_mac[0] == mac:
                band_el.remove(direct)

        self.wvm.defineXML(etree.tostring(tree))

    def add_guest_agent(self):
        channel_xml = """
                        <channel type='unix'>
                            <target type='virtio' name='org.qemu.guest_agent.0'/>
                        </channel>
                      """
        if self.get_status() == 1:
            self.instance.attachDeviceFlags(channel_xml, VIR_DOMAIN_AFFECT_LIVE)
            self.instance.attachDeviceFlags(channel_xml, VIR_DOMAIN_AFFECT_CONFIG)
        if self.get_status() == 5:
            self.instance.attachDeviceFlags(channel_xml, VIR_DOMAIN_AFFECT_CONFIG)

    def remove_guest_agent(self):
        tree = etree.fromstring(self._XMLDesc(0))
        for target in tree.xpath("/domain/devices/channel[@type='unix']/target[@name='org.qemu.guest_agent.0']"):
            parent = target.getparent()
            channel_xml = etree.tostring(parent)
            if self.get_status() == 1:
                self.instance.detachDeviceFlags(channel_xml, VIR_DOMAIN_AFFECT_LIVE)
                self.instance.detachDeviceFlags(channel_xml, VIR_DOMAIN_AFFECT_CONFIG)
            if self.get_status() == 5:
                self.instance.detachDeviceFlags(channel_xml, VIR_DOMAIN_AFFECT_CONFIG)

    def get_guest_agent(self):
        def _get_agent(doc):
            """
            Return agent channel object if it is defined.
            """
            for channel in doc.xpath('/domain/devices/channel'):
                ch_type = channel.get("type")
                target = channel.find("target")
                target_name = target.get("name")
                if ch_type == "unix" and target_name == "org.qemu.guest_agent.0":
                    return channel
            return None

        return util.get_xml_path(self._XMLDesc(0), func=_get_agent)

    def is_agent_ready(self):
        """
        Return connected state of an agent.
        """
        # we need to get a fresh agent channel object on each call so it
        # reflects the current state
        dev = self.get_guest_agent()
        if dev is not None:
            states = dev.xpath("target/@state")
            state = states[0] if len(states) > 0 else ''
            if state == "connected":
                return True
            return False