gns3-server/gns3server/compute/qemu/qemu_vm.py

# -*- coding: utf-8 -*-
#
# Copyright (C) 2014 GNS3 Technologies Inc.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

"""
QEMU VM management (creates command line, processes, files etc.) in
order to run a QEMU VM.
"""

import sys
import os
import re
import math
import shutil
import asyncio
import socket
import gns3server
import subprocess
import time
import json

from gns3server.utils import parse_version, shlex_quote
from gns3server.utils.asyncio import subprocess_check_output, cancellable_wait_run_in_executor
from .qemu_error import QemuError
from .utils.qcow2 import Qcow2, Qcow2Error
from ..adapters.ethernet_adapter import EthernetAdapter
from ..nios.nio_udp import NIOUDP
from ..nios.nio_tap import NIOTAP
from ..base_node import BaseNode
from ...schemas.qemu import QEMU_OBJECT_SCHEMA, QEMU_PLATFORMS
from ...utils.asyncio import monitor_process
from ...utils.images import md5sum
from ...utils import macaddress_to_int, int_to_macaddress


import logging
log = logging.getLogger(__name__)


class QemuVM(BaseNode):
    module_name = 'qemu'

    """
    QEMU VM implementation.

    :param name: Qemu VM name
    :param node_id: Node identifier
    :param project: Project instance
    :param manager: Manager instance
    :param console: TCP console port
    :param console_type: Console type
    :param qemu_path: path to the QEMU binary
    :param platform: Platform to emulate
    """

    def __init__(self, name, node_id, project, manager, linked_clone=True, qemu_path=None, console=None, console_type="telnet", platform=None):

        super().__init__(name, node_id, project, manager, console=console, console_type=console_type, linked_clone=linked_clone, wrap_console=True)
        server_config = manager.config.get_section_config("Server")
        self._host = server_config.get("host", "127.0.0.1")
        self._monitor_host = server_config.get("monitor_host", "127.0.0.1")
        self._process = None
        self._cpulimit_process = None
        self._monitor = None
        self._stdout_file = ""
        self._qemu_img_stdout_file = ""
        self._execute_lock = asyncio.Lock()
        self._local_udp_tunnels = {}
        self._guest_cid = None

        # QEMU VM settings
        if qemu_path:
            try:
                self.qemu_path = qemu_path
            except QemuError as e:
                # If the binary is not found for topologies 1.4 and later
                # search via the platform otherwise use the binary name
                if platform:
                    self.platform = platform
                else:
                    self.qemu_path = os.path.basename(qemu_path)
        else:
            self.platform = platform

        self._hda_disk_image = ""
        self._hdb_disk_image = ""
        self._hdc_disk_image = ""
        self._hdd_disk_image = ""
        self._hda_disk_interface = "ide"
        self._hdb_disk_interface = "ide"
        self._hdc_disk_interface = "ide"
        self._hdd_disk_interface = "ide"
        self._cdrom_image = ""
        self._bios_image = ""
        self._boot_priority = "c"
        self._mac_address = ""
        self._options = ""
        self._ram = 256
        self._cpus = 1
        self._ethernet_adapters = []
        self._adapter_type = "e1000"
        self._initrd = ""
        self._kernel_image = ""
        self._kernel_command_line = ""
        self._legacy_networking = False
        self._on_close = "power_off"
        self._cpu_throttling = 0  # means no CPU throttling
        self._process_priority = "low"

        self.mac_address = ""  # this will generate a MAC address
        self.adapters = 1  # creates 1 adapter by default
        log.info('QEMU VM "{name}" [{id}] has been created'.format(name=self._name, id=self._id))

    @property
    def guest_cid(self):
        """
        Returns the CID (console ID) which is an unique identifier between 3 and 65535

        :returns: integer between 3 and 65535
        """

        return self._guest_cid

    @guest_cid.setter
    def guest_cid(self, guest_cid):
        """
        Set the CID (console ID) which is an unique identifier between 3 and 65535

        :returns: integer between 3 and 65535
        """

        self._guest_cid = guest_cid

    @property
    def monitor(self):
        """
        Returns the TCP monitor port.

        :returns: monitor port (integer)
        """

        return self._monitor

    @property
    def qemu_path(self):
        """
        Returns the QEMU binary path for this QEMU VM.

        :returns: QEMU path
        """

        return self._qemu_path

    @qemu_path.setter
    def qemu_path(self, qemu_path):
        """
        Sets the QEMU binary path this QEMU VM.

        :param qemu_path: QEMU path
        """

        if qemu_path and os.pathsep not in qemu_path:
            if sys.platform.startswith("win") and ".exe" not in qemu_path.lower():
                qemu_path += "w.exe"
            new_qemu_path = shutil.which(qemu_path, path=os.pathsep.join(self._manager.paths_list()))
            if new_qemu_path is None:
                raise QemuError("QEMU binary path {} is not found in the path".format(qemu_path))
            qemu_path = new_qemu_path

        self._check_qemu_path(qemu_path)
        self._qemu_path = qemu_path
        self._platform = os.path.basename(qemu_path)
        if self._platform == "qemu-kvm":
            self._platform = "x86_64"
        else:
            qemu_bin = os.path.basename(qemu_path)
            qemu_bin = re.sub(r'(w)?\.(exe|EXE)$', '', qemu_bin)
            # Old version of GNS3 provide a binary named qemu.exe
            if qemu_bin == "qemu":
                self._platform = "i386"
            else:
                self._platform = re.sub(r'^qemu-system-(.*)$', r'\1', qemu_bin, re.IGNORECASE)
        if self._platform.split(".")[0] not in QEMU_PLATFORMS:
            raise QemuError("Platform {} is unknown".format(self._platform))
        log.info('QEMU VM "{name}" [{id}] has set the QEMU path to {qemu_path}'.format(name=self._name,
                                                                                       id=self._id,
                                                                                       qemu_path=qemu_path))

    def _check_qemu_path(self, qemu_path):

        if qemu_path is None:
            raise QemuError("QEMU binary path is not set")
        if not os.path.exists(qemu_path):
            raise QemuError("QEMU binary '{}' is not accessible".format(qemu_path))
        if not os.access(qemu_path, os.X_OK):
            raise QemuError("QEMU binary '{}' is not executable".format(qemu_path))

    @property
    def platform(self):
        """
        Return the current platform
        """
        return self._platform

    @platform.setter
    def platform(self, platform):

        self._platform = platform
        if sys.platform.startswith("win"):
            self.qemu_path = "qemu-system-{}w.exe".format(platform)
        else:
            self.qemu_path = "qemu-system-{}".format(platform)

    def _disk_setter(self, variable, value):
        """
        Use by disk image setter for checking and apply modifications

        :param variable: Variable name in the class
        :param value: New disk value
        """

        value = self.manager.get_abs_image_path(value, self.project.path)
        if not self.linked_clone:
            for node in self.manager.nodes:
                if node != self and getattr(node, variable) == value:
                    raise QemuError("Sorry a node without the linked base setting enabled can only be used once on your server. {} is already used by {}".format(value, node.name))
        setattr(self, "_" + variable, value)
        log.info('QEMU VM "{name}" [{id}] has set the QEMU {variable} path to {disk_image}'.format(name=self._name,
                                                                                                   variable=variable,
                                                                                                   id=self._id,
                                                                                                   disk_image=value))

    @property
    def hda_disk_image(self):
        """
        Returns the hda disk image path for this QEMU VM.

        :returns: QEMU hda disk image path
        """

        return self._hda_disk_image

    @hda_disk_image.setter
    def hda_disk_image(self, hda_disk_image):
        """
        Sets the hda disk image for this QEMU VM.

        :param hda_disk_image: QEMU hda disk image path
        """

        self._disk_setter("hda_disk_image", hda_disk_image)

    @property
    def hdb_disk_image(self):
        """
        Returns the hdb disk image path for this QEMU VM.

        :returns: QEMU hdb disk image path
        """

        return self._hdb_disk_image

    @hdb_disk_image.setter
    def hdb_disk_image(self, hdb_disk_image):
        """
        Sets the hdb disk image for this QEMU VM.

        :param hdb_disk_image: QEMU hdb disk image path
        """

        self._disk_setter("hdb_disk_image", hdb_disk_image)

    @property
    def hdc_disk_image(self):
        """
        Returns the hdc disk image path for this QEMU VM.

        :returns: QEMU hdc disk image path
        """

        return self._hdc_disk_image

    @hdc_disk_image.setter
    def hdc_disk_image(self, hdc_disk_image):
        """
        Sets the hdc disk image for this QEMU VM.

        :param hdc_disk_image: QEMU hdc disk image path
        """

        self._disk_setter("hdc_disk_image", hdc_disk_image)

    @property
    def hdd_disk_image(self):
        """
        Returns the hdd disk image path for this QEMU VM.

        :returns: QEMU hdd disk image path
        """

        return self._hdd_disk_image

    @hdd_disk_image.setter
    def hdd_disk_image(self, hdd_disk_image):
        """
        Sets the hdd disk image for this QEMU VM.

        :param hdd_disk_image: QEMU hdd disk image path
        """

        self._disk_setter("hdd_disk_image", hdd_disk_image)

    @property
    def hda_disk_interface(self):
        """
        Returns the hda disk interface this QEMU VM.

        :returns: QEMU hda disk interface
        """

        return self._hda_disk_interface

    @hda_disk_interface.setter
    def hda_disk_interface(self, hda_disk_interface):
        """
        Sets the hda disk interface for this QEMU VM.

        :param hda_disk_interface: QEMU hda disk interface
        """

        self._hda_disk_interface = hda_disk_interface
        log.info('QEMU VM "{name}" [{id}] has set the QEMU hda disk interface to {interface}'.format(name=self._name,
                                                                                                     id=self._id,
                                                                                                     interface=self._hda_disk_interface))

    @property
    def hdb_disk_interface(self):
        """
        Returns the hdb disk interface this QEMU VM.

        :returns: QEMU hdb disk interface
        """

        return self._hdb_disk_interface

    @hdb_disk_interface.setter
    def hdb_disk_interface(self, hdb_disk_interface):
        """
        Sets the hda disk interface for this QEMU VM.

        :param hdb_disk_interface: QEMU hdb disk interface
        """

        self._hdb_disk_interface = hdb_disk_interface
        log.info('QEMU VM "{name}" [{id}] has set the QEMU hdb disk interface to {interface}'.format(name=self._name,
                                                                                                     id=self._id,
                                                                                                     interface=self._hdb_disk_interface))

    @property
    def hdc_disk_interface(self):
        """
        Returns the hdc disk interface this QEMU VM.

        :returns: QEMU hdc disk interface
        """

        return self._hdc_disk_interface

    @hdc_disk_interface.setter
    def hdc_disk_interface(self, hdc_disk_interface):
        """
        Sets the hdc disk interface for this QEMU VM.

        :param hdc_disk_interface: QEMU hdc disk interface
        """

        self._hdc_disk_interface = hdc_disk_interface
        log.info('QEMU VM "{name}" [{id}] has set the QEMU hdc disk interface to {interface}'.format(name=self._name,
                                                                                                     id=self._id,
                                                                                                     interface=self._hdc_disk_interface))

    @property
    def hdd_disk_interface(self):
        """
        Returns the hda disk interface this QEMU VM.

        :returns: QEMU hda disk interface
        """

        return self._hdd_disk_interface

    @hdd_disk_interface.setter
    def hdd_disk_interface(self, hdd_disk_interface):
        """
        Sets the hdd disk interface for this QEMU VM.

        :param hdd_disk_interface: QEMU hdd disk interface
        """

        self._hdd_disk_interface = hdd_disk_interface
        log.info('QEMU VM "{name}" [{id}] has set the QEMU hdd disk interface to {interface}'.format(name=self._name,
                                                                                                     id=self._id,
                                                                                                     interface=self._hdd_disk_interface))

    @property
    def cdrom_image(self):
        """
        Returns the cdrom image path for this QEMU VM.

        :returns: QEMU cdrom image path
        """

        return self._cdrom_image

    @cdrom_image.setter
    def cdrom_image(self, cdrom_image):
        """
        Sets the cdrom image for this QEMU VM.

        :param cdrom_image: QEMU cdrom image path
        """

        if cdrom_image:
            self._cdrom_image = self.manager.get_abs_image_path(cdrom_image, self.project.path)

            log.info('QEMU VM "{name}" [{id}] has set the QEMU cdrom image path to {cdrom_image}'.format(name=self._name,
                                                                                                         id=self._id,
                                                                                                         cdrom_image=self._cdrom_image))
        else:
            self._cdrom_image = ""

    async def update_cdrom_image(self):
        """
        Update the cdrom image path for the Qemu guest OS
        """

        if self.is_running():
            if self._cdrom_image:
                self._cdrom_option()  # this will check the cdrom image is accessible
                await self._control_vm("eject -f ide1-cd0")
                await self._control_vm("change ide1-cd0 {}".format(self._cdrom_image))
                log.info('QEMU VM "{name}" [{id}] has changed the cdrom image path to {cdrom_image}'.format(name=self._name,
                                                                                                            id=self._id,
                                                                                                            cdrom_image=self._cdrom_image))
            else:
                await self._control_vm("eject -f ide1-cd0")
                log.info('QEMU VM "{name}" [{id}] has ejected the cdrom image'.format(name=self._name, id=self._id))

    @property
    def bios_image(self):
        """
        Returns the bios image path for this QEMU VM.

        :returns: QEMU bios image path
        """

        return self._bios_image

    @bios_image.setter
    def bios_image(self, bios_image):
        """
        Sets the bios image for this QEMU VM.

        :param bios_image: QEMU bios image path
        """

        self._bios_image = self.manager.get_abs_image_path(bios_image, self.project.path)
        log.info('QEMU VM "{name}" [{id}] has set the QEMU bios image path to {bios_image}'.format(name=self._name,
                                                                                                   id=self._id,
                                                                                                   bios_image=self._bios_image))

    @property
    def boot_priority(self):
        """
        Returns the boot priority for this QEMU VM.

        :returns: QEMU boot priority
        """

        return self._boot_priority

    @boot_priority.setter
    def boot_priority(self, boot_priority):
        """
        Sets the boot priority for this QEMU VM.

        :param boot_priority: QEMU boot priority
        """

        self._boot_priority = boot_priority
        log.info('QEMU VM "{name}" [{id}] has set the boot priority to {boot_priority}'.format(name=self._name,
                                                                                               id=self._id,
                                                                                               boot_priority=self._boot_priority))

    @property
    def ethernet_adapters(self):
        """
        Return the list of ethernet adapters of the node
        """
        return self._ethernet_adapters

    @property
    def adapters(self):
        """
        Returns the number of Ethernet adapters for this QEMU VM.

        :returns: number of adapters
        """

        return len(self._ethernet_adapters)

    @adapters.setter
    def adapters(self, adapters):
        """
        Sets the number of Ethernet adapters for this QEMU VM.

        :param adapters: number of adapters
        """

        self._ethernet_adapters.clear()
        for adapter_number in range(0, adapters):
            self._ethernet_adapters.append(EthernetAdapter())

        log.info('QEMU VM "{name}" [{id}]: number of Ethernet adapters changed to {adapters}'.format(name=self._name,
                                                                                                     id=self._id,
                                                                                                     adapters=adapters))

    @property
    def adapter_type(self):
        """
        Returns the adapter type for this QEMU VM.

        :returns: adapter type (string)
        """

        return self._adapter_type

    @adapter_type.setter
    def adapter_type(self, adapter_type):
        """
        Sets the adapter type for this QEMU VM.

        :param adapter_type: adapter type (string)
        """

        self._adapter_type = adapter_type

        log.info('QEMU VM "{name}" [{id}]: adapter type changed to {adapter_type}'.format(name=self._name,
                                                                                          id=self._id,
                                                                                          adapter_type=adapter_type))

    @property
    def mac_address(self):
        """
        Returns the MAC address for this QEMU VM.

        :returns: adapter type (string)
        """

        return self._mac_address

    @mac_address.setter
    def mac_address(self, mac_address):
        """
        Sets the MAC address for this QEMU VM.

        :param mac_address: MAC address
        """

        if not mac_address:
            # use the node UUID to generate a random MAC address
            self._mac_address = "0c:%s:%s:%s:%s:00" % (self.project.id[-4:-2], self.project.id[-2:], self.id[-4:-2], self.id[-2:])
        else:
            self._mac_address = mac_address

        log.info('QEMU VM "{name}" [{id}]: MAC address changed to {mac_addr}'.format(name=self._name,
                                                                                     id=self._id,
                                                                                     mac_addr=self._mac_address))

    @property
    def legacy_networking(self):
        """
        Returns either QEMU legacy networking commands are used.

        :returns: boolean
        """

        return self._legacy_networking

    @legacy_networking.setter
    def legacy_networking(self, legacy_networking):
        """
        Sets either QEMU legacy networking commands are used.

        :param legacy_networking: boolean
        """

        if legacy_networking:
            log.info('QEMU VM "{name}" [{id}] has enabled legacy networking'.format(name=self._name, id=self._id))
        else:
            log.info('QEMU VM "{name}" [{id}] has disabled legacy networking'.format(name=self._name, id=self._id))
        self._legacy_networking = legacy_networking

    @property
    def on_close(self):
        """
        Returns the action to execute when the VM is stopped/closed

        :returns: string
        """

        return self._on_close

    @on_close.setter
    def on_close(self, on_close):
        """
        Sets the action to execute when the VM is stopped/closed

        :param on_close: string
        """

        log.info('QEMU VM "{name}" [{id}] set the close action to "{action}"'.format(name=self._name, id=self._id, action=on_close))
        self._on_close = on_close

    @property
    def cpu_throttling(self):
        """
        Returns the percentage of CPU allowed.

        :returns: integer
        """

        return self._cpu_throttling

    @cpu_throttling.setter
    def cpu_throttling(self, cpu_throttling):
        """
        Sets the percentage of CPU allowed.

        :param cpu_throttling: integer
        """

        log.info('QEMU VM "{name}" [{id}] has set the percentage of CPU allowed to {cpu}'.format(name=self._name,
                                                                                                 id=self._id,
                                                                                                 cpu=cpu_throttling))
        self._cpu_throttling = cpu_throttling
        self._stop_cpulimit()
        if cpu_throttling:
            self._set_cpu_throttling()

    @property
    def process_priority(self):
        """
        Returns the process priority.

        :returns: string
        """

        return self._process_priority

    @process_priority.setter
    def process_priority(self, process_priority):
        """
        Sets the process priority.

        :param process_priority: string
        """

        log.info('QEMU VM "{name}" [{id}] has set the process priority to {priority}'.format(name=self._name,
                                                                                             id=self._id,
                                                                                             priority=process_priority))
        self._process_priority = process_priority

    @property
    def ram(self):
        """
        Returns the RAM amount for this QEMU VM.

        :returns: RAM amount in MB
        """

        return self._ram

    @ram.setter
    def ram(self, ram):
        """
        Sets the amount of RAM for this QEMU VM.

        :param ram: RAM amount in MB
        """

        log.info('QEMU VM "{name}" [{id}] has set the RAM to {ram}'.format(name=self._name, id=self._id, ram=ram))
        self._ram = ram

    @property
    def cpus(self):
        """
        Returns the number of vCPUs this QEMU VM.

        :returns: number of vCPUs.
        """

        return self._cpus

    @cpus.setter
    def cpus(self, cpus):
        """
        Sets the number of vCPUs this QEMU VM.

        :param cpus: number of vCPUs.
        """

        log.info('QEMU VM "{name}" [{id}] has set the number of vCPUs to {cpus}'.format(name=self._name, id=self._id, cpus=cpus))
        self._cpus = cpus

    @property
    def options(self):
        """
        Returns the options for this QEMU VM.

        :returns: QEMU options
        """

        return self._options

    @options.setter
    def options(self, options):
        """
        Sets the options for this QEMU VM.

        :param options: QEMU options
        """

        log.info('QEMU VM "{name}" [{id}] has set the QEMU options to {options}'.format(name=self._name,
                                                                                        id=self._id,
                                                                                        options=options))

        if not sys.platform.startswith("linux"):
            if "-no-kvm" in options:
                options = options.replace("-no-kvm", "")
            if "-enable-kvm" in options:
                options = options.replace("-enable-kvm", "")
        else:
            if "-no-hax" in options:
                options = options.replace("-no-hax", "")
            if "-enable-hax" in options:
                options = options.replace("-enable-hax", "")
            if "-icount" in options and ("-no-kvm" not in options):
                # automatically add the -no-kvm option if -icount is detected
                # to help with the migration of ASA VMs created before version 1.4
                options = "-no-kvm " + options
        self._options = options.strip()

    @property
    def initrd(self):
        """
        Returns the initrd path for this QEMU VM.

        :returns: QEMU initrd path
        """

        return self._initrd

    @initrd.setter
    def initrd(self, initrd):
        """
        Sets the initrd path for this QEMU VM.

        :param initrd: QEMU initrd path
        """

        initrd = self.manager.get_abs_image_path(initrd, self.project.path)

        log.info('QEMU VM "{name}" [{id}] has set the QEMU initrd path to {initrd}'.format(name=self._name,
                                                                                           id=self._id,
                                                                                           initrd=initrd))
        if "asa" in initrd and self._initrd != initrd:
            self.project.emit("log.warning", {"message": "Warning ASA 8 is not supported by GNS3 and Cisco, please use ASAv instead. Depending of your hardware and OS this could not work or you could be limited to one instance. If ASA 8 is not booting their is no GNS3 solution, you must to upgrade to ASAv."})
        self._initrd = initrd

    @property
    def kernel_image(self):
        """
        Returns the kernel image path for this QEMU VM.

        :returns: QEMU kernel image path
        """

        return self._kernel_image

    @kernel_image.setter
    def kernel_image(self, kernel_image):
        """
        Sets the kernel image path for this QEMU VM.

        :param kernel_image: QEMU kernel image path
        """

        kernel_image = self.manager.get_abs_image_path(kernel_image, self.project.path)
        log.info('QEMU VM "{name}" [{id}] has set the QEMU kernel image path to {kernel_image}'.format(name=self._name,
                                                                                                       id=self._id,
                                                                                                       kernel_image=kernel_image))
        self._kernel_image = kernel_image

    @property
    def kernel_command_line(self):
        """
        Returns the kernel command line for this QEMU VM.

        :returns: QEMU kernel command line
        """

        return self._kernel_command_line

    @kernel_command_line.setter
    def kernel_command_line(self, kernel_command_line):
        """
        Sets the kernel command line for this QEMU VM.

        :param kernel_command_line: QEMU kernel command line
        """

        log.info('QEMU VM "{name}" [{id}] has set the QEMU kernel command line to {kernel_command_line}'.format(name=self._name,
                                                                                                                id=self._id,
                                                                                                                kernel_command_line=kernel_command_line))
        self._kernel_command_line = kernel_command_line

    async def _set_process_priority(self):
        """
        Changes the process priority
        """

        if self._process_priority == "normal":
            return

        if sys.platform.startswith("win"):
            try:
                import win32api
                import win32con
                import win32process
            except ImportError:
                log.error("pywin32 must be installed to change the priority class for QEMU VM {}".format(self._name))
            else:
                log.info("Setting QEMU VM {} priority class to {}".format(self._name, self._process_priority))
                handle = win32api.OpenProcess(win32con.PROCESS_ALL_ACCESS, 0, self._process.pid)
                if self._process_priority == "realtime":
                    priority = win32process.REALTIME_PRIORITY_CLASS
                elif self._process_priority == "very high":
                    priority = win32process.HIGH_PRIORITY_CLASS
                elif self._process_priority == "high":
                    priority = win32process.ABOVE_NORMAL_PRIORITY_CLASS
                elif self._process_priority == "low":
                    priority = win32process.BELOW_NORMAL_PRIORITY_CLASS
                elif self._process_priority == "very low":
                    priority = win32process.IDLE_PRIORITY_CLASS
                else:
                    priority = win32process.NORMAL_PRIORITY_CLASS
                try:
                    win32process.SetPriorityClass(handle, priority)
                except win32process.error as e:
                    log.error('Could not change process priority for QEMU VM "{}": {}'.format(self._name, e))
        else:
            if self._process_priority == "realtime":
                priority = -20
            elif self._process_priority == "very high":
                priority = -15
            elif self._process_priority == "high":
                priority = -5
            elif self._process_priority == "low":
                priority = 5
            elif self._process_priority == "very low":
                priority = 19
            else:
                priority = 0
            try:
                process = await asyncio.create_subprocess_exec('renice', '-n', str(priority), '-p', str(self._process.pid))
                await process.wait()
            except (OSError, subprocess.SubprocessError) as e:
                log.error('Could not change process priority for QEMU VM "{}": {}'.format(self._name, e))

    def _stop_cpulimit(self):
        """
        Stops the cpulimit process.
        """

        if self._cpulimit_process and self._cpulimit_process.returncode is None:
            self._cpulimit_process.kill()
            try:
                self._process.wait(3)
            except subprocess.TimeoutExpired:
                log.error("Could not kill cpulimit process {}".format(self._cpulimit_process.pid))

    def _set_cpu_throttling(self):
        """
        Limits the CPU usage for current QEMU process.
        """

        if not self.is_running():
            return

        try:
            if sys.platform.startswith("win") and hasattr(sys, "frozen"):
                cpulimit_exec = os.path.join(os.path.dirname(os.path.abspath(sys.executable)), "cpulimit", "cpulimit.exe")
            else:
                cpulimit_exec = "cpulimit"
            subprocess.Popen([cpulimit_exec, "--lazy", "--pid={}".format(self._process.pid), "--limit={}".format(self._cpu_throttling)], cwd=self.working_dir)
            log.info("CPU throttled to {}%".format(self._cpu_throttling))
        except FileNotFoundError:
            raise QemuError("cpulimit could not be found, please install it or deactivate CPU throttling")
        except (OSError, subprocess.SubprocessError) as e:
            raise QemuError("Could not throttle CPU: {}".format(e))

    async def create(self):
        """
        Creates QEMU VM and sets proper MD5 hashes
        """

        # In case user upload image manually we don't have md5 sums.
        # We need generate hashes at this point, otherwise they will be generated
        # at __json__ but not on separate thread.
        await cancellable_wait_run_in_executor(md5sum, self._hda_disk_image)
        await cancellable_wait_run_in_executor(md5sum, self._hdb_disk_image)
        await cancellable_wait_run_in_executor(md5sum, self._hdc_disk_image)
        await cancellable_wait_run_in_executor(md5sum, self._hdd_disk_image)

        super(QemuVM, self).create()

    async def start(self):
        """
        Starts this QEMU VM.
        """

        async with self._execute_lock:
            if self.is_running():
                # resume the VM if it is paused
                await self.resume()
                return

            if self._manager.config.get_section_config("Qemu").getboolean("monitor", True):
                try:
                    info = socket.getaddrinfo(self._monitor_host, 0, socket.AF_UNSPEC, socket.SOCK_STREAM, 0, socket.AI_PASSIVE)
                    if not info:
                        raise QemuError("getaddrinfo returns an empty list on {}".format(self._monitor_host))
                    for res in info:
                        af, socktype, proto, _, sa = res
                        # let the OS find an unused port for the Qemu monitor
                        with socket.socket(af, socktype, proto) as sock:
                            sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
                            sock.bind(sa)
                            self._monitor = sock.getsockname()[1]
                except OSError as e:
                    raise QemuError("Could not find free port for the Qemu monitor: {}".format(e))

            # check if there is enough RAM to run
            self.check_available_ram(self.ram)

            command = await self._build_command()
            command_string = " ".join(shlex_quote(s) for s in command)
            try:
                log.info("Starting QEMU with: {}".format(command_string))
                self._stdout_file = os.path.join(self.working_dir, "qemu.log")
                log.info("logging to {}".format(self._stdout_file))
                with open(self._stdout_file, "w", encoding="utf-8") as fd:
                    fd.write("Start QEMU with {}\n\nExecution log:\n".format(command_string))
                    self.command_line = ' '.join(command)
                    self._process = await asyncio.create_subprocess_exec(*command,
                                                                              stdout=fd,
                                                                              stderr=subprocess.STDOUT,
                                                                              cwd=self.working_dir)
                log.info('QEMU VM "{}" started PID={}'.format(self._name, self._process.pid))
                self.status = "started"
                monitor_process(self._process, self._termination_callback)
            except (OSError, subprocess.SubprocessError, UnicodeEncodeError) as e:
                stdout = self.read_stdout()
                log.error("Could not start QEMU {}: {}\n{}".format(self.qemu_path, e, stdout))
                raise QemuError("Could not start QEMU {}: {}\n{}".format(self.qemu_path, e, stdout))

            await self._set_process_priority()
            if self._cpu_throttling:
                self._set_cpu_throttling()

            if "-enable-kvm" in command_string or "-enable-hax" in command_string:
                self._hw_virtualization = True

            await self._start_ubridge()
            set_link_commands = []
            for adapter_number, adapter in enumerate(self._ethernet_adapters):
                nio = adapter.get_nio(0)
                if nio:
                    await self.add_ubridge_udp_connection("QEMU-{}-{}".format(self._id, adapter_number),
                                                               self._local_udp_tunnels[adapter_number][1],
                                                               nio)
                    if nio.suspend:
                        set_link_commands.append("set_link gns3-{} off".format(adapter_number))
                else:
                    set_link_commands.append("set_link gns3-{} off".format(adapter_number))

            if "-loadvm" not in command_string:
                # only set the link statuses if not restoring a previous VM state
                await self._control_vm_commands(set_link_commands)

        try:
            if self.is_running():
                await self.start_wrap_console()
        except OSError as e:
            raise QemuError("Could not start Telnet QEMU console {}\n".format(e))

    async def _termination_callback(self, returncode):
        """
        Called when the process has stopped.

        :param returncode: Process returncode
        """

        if self.started:
            log.info("QEMU process has stopped, return code: %d", returncode)
            await self.stop()
            # A return code of 1 seem fine on Windows
            if returncode != 0 and (not sys.platform.startswith("win") or returncode != 1):
                self.project.emit("log.error", {"message": "QEMU process has stopped, return code: {}\n{}".format(returncode, self.read_stdout())})

    async def stop(self):
        """
        Stops this QEMU VM.
        """

        await self._stop_ubridge()
        async with self._execute_lock:
            # stop the QEMU process
            self._hw_virtualization = False
            if self.is_running():
                log.info('Stopping QEMU VM "{}" PID={}'.format(self._name, self._process.pid))
                try:

                    if self.on_close == "save_vm_state":
                        await self._control_vm("stop")
                        await self._control_vm("savevm GNS3_SAVED_STATE")
                        wait_for_savevm = 120
                        while wait_for_savevm:
                            await asyncio.sleep(1)
                            status = await self._saved_state_option()
                            wait_for_savevm -= 1
                            if status != []:
                                break

                    if self.on_close == "shutdown_signal":
                        await self._control_vm("system_powerdown")
                        await gns3server.utils.asyncio.wait_for_process_termination(self._process, timeout=120)
                    else:
                        self._process.terminate()
                        await gns3server.utils.asyncio.wait_for_process_termination(self._process, timeout=3)
                except ProcessLookupError:
                    pass
                except asyncio.TimeoutError:
                    if self._process:
                        try:
                            self._process.kill()
                        except ProcessLookupError:
                            pass
                        if self._process.returncode is None:
                            log.warning('QEMU VM "{}" PID={} is still running'.format(self._name, self._process.pid))
            self._process = None
            self._stop_cpulimit()
            if self.on_close != "save_vm_state":
                await self._clear_save_vm_stated()
            await super().stop()

    async def _open_qemu_monitor_connection_vm(self, timeout=10):
        """
        Opens a connection to the QEMU monitor.

        :param timeout: timeout to connect to the monitor TCP server
        :returns: The reader returned is a StreamReader instance; the writer is a StreamWriter instance
        """

        begin = time.time()
        connection_success = False
        last_exception = None
        reader = writer = None
        while time.time() - begin < timeout:
            await asyncio.sleep(0.01)
            try:
                log.debug("Connecting to Qemu monitor on {}:{}".format(self._monitor_host, self._monitor))
                reader, writer = await asyncio.open_connection(self._monitor_host, self._monitor)
            except (asyncio.TimeoutError, OSError) as e:
                last_exception = e
                continue
            connection_success = True
            break

        if not connection_success:
            log.warning("Could not connect to QEMU monitor on {}:{}: {}".format(self._monitor_host, self._monitor,
                                                                                last_exception))
        else:
            log.info("Connected to QEMU monitor on {}:{} after {:.4f} seconds".format(self._monitor_host, self._monitor, time.time() - begin))
        return reader, writer

    async def _control_vm(self, command, expected=None):
        """
        Executes a command with QEMU monitor when this VM is running.

        :param command: QEMU monitor command (e.g. info status, stop etc.)
        :param expected: An array of expected strings

        :returns: result of the command (matched object or None)
        """

        result = None
        if self.is_running() and self._monitor:
            log.info("Execute QEMU monitor command: {}".format(command))
            reader, writer = await self._open_qemu_monitor_connection_vm()
            if reader is None and writer is None:
                return result

            try:
                cmd_byte = command.encode('ascii')
                writer.write(cmd_byte + b"\n")
                if not expected:
                    while True:
                        line = await asyncio.wait_for(reader.readline(), timeout=3)  # echo of the command
                        if not line or cmd_byte in line:
                            break
            except asyncio.TimeoutError:
                log.warning("Missing echo of command '{}'".format(command))
            except OSError as e:
                log.warning("Could not write to QEMU monitor: {}".format(e))
                writer.close()
                return result
            if expected:
                try:
                    while result is None:
                        line = await asyncio.wait_for(reader.readline(), timeout=3)
                        if not line:
                            break
                        for expect in expected:
                            if expect in line:
                                result = line.decode("utf-8").strip()
                                break
                except asyncio.TimeoutError:
                    log.warning("Timeout while waiting for result of command '{}'".format(command))
                except (ConnectionError, EOFError) as e:
                    log.warning("Could not read from QEMU monitor: {}".format(e))
            writer.close()
        return result

    async def _control_vm_commands(self, commands):
        """
        Executes commands with QEMU monitor when this VM is running.

        :param commands: a list of QEMU monitor commands (e.g. info status, stop etc.)
        """

        if self.is_running() and self._monitor:

            reader, writer = await self._open_qemu_monitor_connection_vm()
            if reader is None and writer is None:
                return

            for command in commands:
                log.info("Execute QEMU monitor command: {}".format(command))
                try:
                    writer.write(command.encode('ascii') + b"\n")
                    await asyncio.wait_for(reader.readline(), timeout=3)  # echo of the command
                except asyncio.TimeoutError:
                    log.warning("Missing echo of command '{}'".format(command))
                except OSError as e:
                    log.warning("Could not write to QEMU monitor: {}".format(e))
            writer.close()

    async def close(self):
        """
        Closes this QEMU VM.
        """

        if not (await super().close()):
            return False

        #FIXME: Don't wait for ACPI shutdown when closing the project, should we?
        if self.on_close == "shutdown_signal":
            self.on_close = "power_off"
        await self.stop()

        for adapter in self._ethernet_adapters:
            if adapter is not None:
                for nio in adapter.ports.values():
                    if nio and isinstance(nio, NIOUDP):
                        self.manager.port_manager.release_udp_port(nio.lport, self._project)

        for udp_tunnel in self._local_udp_tunnels.values():
            self.manager.port_manager.release_udp_port(udp_tunnel[0].lport, self._project)
            self.manager.port_manager.release_udp_port(udp_tunnel[1].lport, self._project)
        self._local_udp_tunnels = {}

    async def _get_vm_status(self):
        """
        Returns this VM suspend status.

        Status are extracted from:
          https://github.com/qemu/qemu/blob/master/qapi-schema.json#L152

        :returns: status (string)
        """

        result = await self._control_vm("info status", [
            b"debug", b"inmigrate", b"internal-error", b"io-error",
            b"paused", b"postmigrate", b"prelaunch", b"finish-migrate",
            b"restore-vm", b"running", b"save-vm", b"shutdown", b"suspended",
            b"watchdog", b"guest-panicked"
        ])
        if result is None:
            return result
        status = result.rsplit(' ', 1)[1]
        if status == "running" or status == "prelaunch":
            self.status = "started"
        elif status == "suspended":
            self.status = "suspended"
        elif status == "shutdown":
            self.status = "stopped"
        return status

    async def suspend(self):
        """
        Suspends this QEMU VM.
        """

        if self.is_running():
            vm_status = await self._get_vm_status()
            if vm_status is None:
                raise QemuError("Suspending a QEMU VM is not supported")
            elif vm_status == "running" or vm_status == "prelaunch":
                await self._control_vm("stop")
                self.status = "suspended"
                log.debug("QEMU VM has been suspended")
            else:
                log.info("QEMU VM is not running to be suspended, current status is {}".format(vm_status))

    async def reload(self):
        """
        Reloads this QEMU VM.
        """

        await self._control_vm("system_reset")
        log.debug("QEMU VM has been reset")

    async def resume(self):
        """
        Resumes this QEMU VM.
        """

        vm_status = await self._get_vm_status()
        if vm_status is None:
            raise QemuError("Resuming a QEMU VM is not supported")
        elif vm_status == "paused":
            await self._control_vm("cont")
            log.debug("QEMU VM has been resumed")
        else:
            log.info("QEMU VM is not paused to be resumed, current status is {}".format(vm_status))

    async def adapter_add_nio_binding(self, adapter_number, nio):
        """
        Adds an adapter NIO binding.

        :param adapter_number: adapter number
        :param nio: NIO instance to add to the adapter
        """

        try:
            adapter = self._ethernet_adapters[adapter_number]
        except IndexError:
            raise QemuError('Adapter {adapter_number} does not exist on QEMU VM "{name}"'.format(name=self._name,
                                                                                                 adapter_number=adapter_number))

        if self.is_running():
            try:
                await self.add_ubridge_udp_connection("QEMU-{}-{}".format(self._id, adapter_number),
                                                           self._local_udp_tunnels[adapter_number][1],
                                                           nio)
                await self._control_vm("set_link gns3-{} on".format(adapter_number))
            except (IndexError, KeyError):
                raise QemuError('Adapter {adapter_number} does not exist on QEMU VM "{name}"'.format(name=self._name,
                                                                                                     adapter_number=adapter_number))

        adapter.add_nio(0, nio)
        log.info('QEMU VM "{name}" [{id}]: {nio} added to adapter {adapter_number}'.format(name=self._name,
                                                                                           id=self._id,
                                                                                           nio=nio,
                                                                                           adapter_number=adapter_number))

    async def adapter_update_nio_binding(self, adapter_number, nio):
        """
        Update an adapter NIO binding.

        :param adapter_number: adapter number
        :param nio: NIO instance to update the adapter
        """

        if self.is_running():
            try:
                await self.update_ubridge_udp_connection("QEMU-{}-{}".format(self._id, adapter_number),
                                                              self._local_udp_tunnels[adapter_number][1],
                                                              nio)
                if nio.suspend:
                    await self._control_vm("set_link gns3-{} off".format(adapter_number))
                else:
                    await self._control_vm("set_link gns3-{} on".format(adapter_number))
            except IndexError:
                raise QemuError('Adapter {adapter_number} does not exist on QEMU VM "{name}"'.format(name=self._name,
                                                                                                     adapter_number=adapter_number))

    async def adapter_remove_nio_binding(self, adapter_number):
        """
        Removes an adapter NIO binding.

        :param adapter_number: adapter number

        :returns: NIO instance
        """

        try:
            adapter = self._ethernet_adapters[adapter_number]
        except IndexError:
            raise QemuError('Adapter {adapter_number} does not exist on QEMU VM "{name}"'.format(name=self._name,
                                                                                                 adapter_number=adapter_number))

        await self.stop_capture(adapter_number)
        if self.is_running():
            await self._control_vm("set_link gns3-{} off".format(adapter_number))
            await self._ubridge_send("bridge delete {name}".format(name="QEMU-{}-{}".format(self._id, adapter_number)))

        nio = adapter.get_nio(0)
        if isinstance(nio, NIOUDP):
            self.manager.port_manager.release_udp_port(nio.lport, self._project)
        adapter.remove_nio(0)

        log.info('QEMU VM "{name}" [{id}]: {nio} removed from adapter {adapter_number}'.format(name=self._name,
                                                                                               id=self._id,
                                                                                               nio=nio,
                                                                                               adapter_number=adapter_number))
        return nio

    def get_nio(self, adapter_number):
        """
        Gets an adapter NIO binding.

        :param adapter_number: adapter number

        :returns: NIO instance
        """

        try:
            adapter = self._ethernet_adapters[adapter_number]
        except IndexError:
            raise QemuError('Adapter {adapter_number} does not exist on QEMU VM "{name}"'.format(name=self._name,
                                                                                                 adapter_number=adapter_number))

        nio = adapter.get_nio(0)

        if not nio:
            raise QemuError("Adapter {} is not connected".format(adapter_number))

        return nio

    async def start_capture(self, adapter_number, output_file):
        """
        Starts a packet capture.

        :param adapter_number: adapter number
        :param output_file: PCAP destination file for the capture
        """

        nio = self.get_nio(adapter_number)
        if nio.capturing:
            raise QemuError("Packet capture is already activated on adapter {adapter_number}".format(adapter_number=adapter_number))

        nio.start_packet_capture(output_file)
        if self.ubridge:
            await self._ubridge_send('bridge start_capture {name} "{output_file}"'.format(name="QEMU-{}-{}".format(self._id, adapter_number),
                                                                                               output_file=output_file))

        log.info("QEMU VM '{name}' [{id}]: starting packet capture on adapter {adapter_number}".format(name=self.name,
                                                                                                       id=self.id,
                                                                                                       adapter_number=adapter_number))

    async def stop_capture(self, adapter_number):
        """
        Stops a packet capture.

        :param adapter_number: adapter number
        """

        nio = self.get_nio(adapter_number)
        if not nio.capturing:
            return

        nio.stop_packet_capture()
        if self.ubridge:
            await self._ubridge_send('bridge stop_capture {name}'.format(name="QEMU-{}-{}".format(self._id, adapter_number)))

        log.info("QEMU VM '{name}' [{id}]: stopping packet capture on adapter {adapter_number}".format(name=self.name,
                                                                                                       id=self.id,
                                                                                                       adapter_number=adapter_number))

    @property
    def started(self):
        """
        Returns either this QEMU VM has been started or not.

        :returns: boolean
        """

        return self.status == "started"

    def read_stdout(self):
        """
        Reads the standard output of the QEMU process.
        Only use when the process has been stopped or has crashed.
        """

        output = ""
        if self._stdout_file:
            try:
                with open(self._stdout_file, "rb") as file:
                    output = file.read().decode("utf-8", errors="replace")
            except OSError as e:
                log.warning("Could not read {}: {}".format(self._stdout_file, e))
        return output

    def read_qemu_img_stdout(self):
        """
        Reads the standard output of the QEMU-IMG process.
        """

        output = ""
        if self._qemu_img_stdout_file:
            try:
                with open(self._qemu_img_stdout_file, "rb") as file:
                    output = file.read().decode("utf-8", errors="replace")
            except OSError as e:
                log.warning("Could not read {}: {}".format(self._qemu_img_stdout_file, e))
        return output

    def is_running(self):
        """
        Checks if the QEMU process is running

        :returns: True or False
        """

        if self._process:
            if self._process.returncode is None:
                return True
            else:
                self._process = None
        return False

    def command(self):
        """
        Returns the QEMU command line.

        :returns: QEMU command line (string)
        """

        return " ".join(self._build_command())

    @BaseNode.console_type.setter
    def console_type(self, new_console_type):
        """
        Sets the console type for this QEMU VM.

        :param new_console_type: console type (string)
        """

        if self.is_running() and self.console_type != new_console_type:
            raise QemuError('"{name}" must be stopped to change the console type to {new_console_type}'.format(name=self._name, new_console_type=new_console_type))

        super(QemuVM, QemuVM).console_type.__set__(self, new_console_type)

    def _serial_options(self):

        if self._console:
            return ["-serial", "telnet:127.0.0.1:{},server,nowait".format(self._internal_console_port)]
        else:
            return []

    def _vnc_options(self):

        if self._console:
            vnc_port = self._console - 5900  # subtract by 5900 to get the display number
            return ["-vnc", "{}:{}".format(self._manager.port_manager.console_host, vnc_port)]
        else:
            return []

    def _spice_options(self):

        if self._console:
            console_host = self._manager.port_manager.console_host
            if console_host == "0.0.0.0" and socket.has_ipv6:
                # to fix an issue with Qemu when IPv4 is not enabled
                # see https://github.com/GNS3/gns3-gui/issues/2352
                # FIXME: consider making this more global (not just for Qemu + SPICE)
                console_host = "::"
            return ["-spice",
                    "addr={},port={},disable-ticketing".format(console_host, self._console),
                    "-vga", "qxl"]
        else:
            return []

    def _spice_with_agent_options(self):

        spice_options = self._spice_options()
        if self._console:
            # agent options (mouse/screen)
            agent_options = ["-device", "virtio-serial",
                             "-chardev", "spicevmc,id=vdagent,debug=0,name=vdagent",
                             "-device", "virtserialport,chardev=vdagent,name=com.redhat.spice.0"]
            spice_options.extend(agent_options)
            # folder sharing options
            folder_sharing_options = ["-chardev", "spiceport,name=org.spice-space.webdav.0,id=charchannel0",
                                      "-device", "virtserialport,chardev=charchannel0,id=channel0,name=org.spice-space.webdav.0"]
            spice_options.extend(folder_sharing_options)
        return spice_options

    def _monitor_options(self):

        if self._monitor:
            return ["-monitor", "tcp:{}:{},server,nowait".format(self._monitor_host, self._monitor)]
        else:
            return []

    def _get_qemu_img(self):
        """
        Search the qemu-img binary in the same binary of the qemu binary
        for avoiding version incompatibility.

        :returns: qemu-img path or raise an error
        """
        qemu_img_path = ""
        qemu_path_dir = os.path.dirname(self.qemu_path)
        try:
            for f in os.listdir(qemu_path_dir):
                if f.startswith("qemu-img"):
                    qemu_img_path = os.path.join(qemu_path_dir, f)
        except OSError as e:
            raise QemuError("Error while looking for qemu-img in {}: {}".format(qemu_path_dir, e))

        if not qemu_img_path:
            raise QemuError("Could not find qemu-img in {}".format(qemu_path_dir))

        return qemu_img_path

    async def _qemu_img_exec(self, command):

        self._qemu_img_stdout_file = os.path.join(self.working_dir, "qemu-img.log")
        log.info("logging to {}".format(self._qemu_img_stdout_file))
        command_string = " ".join(shlex_quote(s) for s in command)
        log.info("Executing qemu-img with: {}".format(command_string))
        with open(self._qemu_img_stdout_file, "w", encoding="utf-8") as fd:
            process = await asyncio.create_subprocess_exec(*command, stdout=fd, stderr=subprocess.STDOUT, cwd=self.working_dir)
        retcode = await process.wait()
        log.info("{} returned with {}".format(self._get_qemu_img(), retcode))
        return retcode

    async def _disk_options(self):
        options = []
        qemu_img_path = self._get_qemu_img()

        drives = ["a", "b", "c", "d"]

        for disk_index, drive in enumerate(drives):
            disk_image = getattr(self, "_hd{}_disk_image".format(drive))
            interface = getattr(self, "hd{}_disk_interface".format(drive))

            if not disk_image:
                continue

            disk_name = "hd" + drive

            if not os.path.isfile(disk_image) or not os.path.exists(disk_image):
                if os.path.islink(disk_image):
                    raise QemuError("{} disk image '{}' linked to '{}' is not accessible".format(disk_name, disk_image, os.path.realpath(disk_image)))
                else:
                    raise QemuError("{} disk image '{}' is not accessible".format(disk_name, disk_image))
            else:
                try:
                    # check for corrupt disk image
                    retcode = await self._qemu_img_exec([qemu_img_path, "check", disk_image])
                    if retcode == 3:
                        # image has leaked clusters, but is not corrupted, let's try to fix it
                        log.warning("Qemu image {} has leaked clusters".format(disk_image))
                        if (await self._qemu_img_exec([qemu_img_path, "check", "-r", "leaks", "{}".format(disk_image)])) == 3:
                            self.project.emit("log.warning", {"message": "Qemu image '{}' has leaked clusters and could not be fixed".format(disk_image)})
                    elif retcode == 2:
                        # image is corrupted, let's try to fix it
                        log.warning("Qemu image {} is corrupted".format(disk_image))
                        if (await self._qemu_img_exec([qemu_img_path, "check", "-r", "all", "{}".format(disk_image)])) == 2:
                            self.project.emit("log.warning", {"message": "Qemu image '{}' is corrupted and could not be fixed".format(disk_image)})
                except (OSError, subprocess.SubprocessError) as e:
                    stdout = self.read_qemu_img_stdout()
                    raise QemuError("Could not check '{}' disk image: {}\n{}".format(disk_name, e, stdout))

            if self.linked_clone:
                disk = os.path.join(self.working_dir, "{}_disk.qcow2".format(disk_name))
                if not os.path.exists(disk):
                    # create the disk
                    try:
                        command = [qemu_img_path, "create", "-o", "backing_file={}".format(disk_image), "-f", "qcow2", disk]
                        retcode = await self._qemu_img_exec(command)
                        if retcode:
                            stdout = self.read_qemu_img_stdout()
                            raise QemuError("Could not create '{}' disk image: qemu-img returned with {}\n{}".format(disk_name,
                                                                                                                     retcode,
                                                                                                                     stdout))
                    except (OSError, subprocess.SubprocessError) as e:
                        stdout = self.read_qemu_img_stdout()
                        raise QemuError("Could not create '{}' disk image: {}\n{}".format(disk_name, e, stdout))
                else:
                    # The disk exists we check if the clone works
                    try:
                        qcow2 = Qcow2(disk)
                        await qcow2.rebase(qemu_img_path, disk_image)
                    except (Qcow2Error, OSError) as e:
                        raise QemuError("Could not use qcow2 disk image '{}' for {} {}".format(disk_image, disk_name, e))

            else:
                disk = disk_image

            if interface == "sata":
                # special case, sata controller doesn't exist in Qemu
                options.extend(["-device", 'ahci,id=ahci{}'.format(disk_index)])
                options.extend(["-drive", 'file={},if=none,id=drive{},index={},media=disk'.format(disk, disk_index, disk_index)])
                options.extend(["-device", 'ide-drive,drive=drive{},bus=ahci{}.0,id=drive{}'.format(disk_index, disk_index, disk_index)])

            else:
                options.extend(["-drive", 'file={},if={},index={},media=disk,id=drive{}'.format(disk, interface, disk_index, disk_index)])

        return options

    async def resize_disk(self, drive_name, extend):

        if self.is_running():
            raise QemuError("Cannot resize {} while the VM is running".format(drive_name))

        if self.linked_clone:
            disk_image_path = os.path.join(self.working_dir, "{}_disk.qcow2".format(drive_name))
        else:
            disk_image_path = getattr(self, "{}_disk_image".format(drive_name))

        if not os.path.exists(disk_image_path):
            raise QemuError("Disk path '{}' does not exist".format(disk_image_path))
        qemu_img_path = self._get_qemu_img()
        await self.manager.resize_disk(qemu_img_path, disk_image_path, extend)

    def _cdrom_option(self):

        options = []
        if self._cdrom_image:
            if not os.path.isfile(self._cdrom_image) or not os.path.exists(self._cdrom_image):
                if os.path.islink(self._cdrom_image):
                    raise QemuError("cdrom image '{}' linked to '{}' is not accessible".format(self._cdrom_image, os.path.realpath(self._cdrom_image)))
                else:
                    raise QemuError("cdrom image '{}' is not accessible".format(self._cdrom_image))
            if self._hdc_disk_image:
                raise QemuError("You cannot use a disk image on hdc disk and a CDROM image at the same time")
            options.extend(["-cdrom", self._cdrom_image])
        return options

    def _bios_option(self):

        options = []
        if self._bios_image:
            if not os.path.isfile(self._bios_image) or not os.path.exists(self._bios_image):
                if os.path.islink(self._bios_image):
                    raise QemuError("bios image '{}' linked to '{}' is not accessible".format(self._bios_image, os.path.realpath(self._bios_image)))
                else:
                    raise QemuError("bios image '{}' is not accessible".format(self._bios_image))
            options.extend(["-bios", self._bios_image])
        return options

    def _linux_boot_options(self):

        options = []
        if self._initrd:
            if not os.path.isfile(self._initrd) or not os.path.exists(self._initrd):
                if os.path.islink(self._initrd):
                    raise QemuError("initrd file '{}' linked to '{}' is not accessible".format(self._initrd, os.path.realpath(self._initrd)))
                else:
                    raise QemuError("initrd file '{}' is not accessible".format(self._initrd))
            options.extend(["-initrd", self._initrd])
        if self._kernel_image:
            if not os.path.isfile(self._kernel_image) or not os.path.exists(self._kernel_image):
                if os.path.islink(self._kernel_image):
                    raise QemuError("kernel image '{}' linked to '{}' is not accessible".format(self._kernel_image, os.path.realpath(self._kernel_image)))
                else:
                    raise QemuError("kernel image '{}' is not accessible".format(self._kernel_image))
            options.extend(["-kernel", self._kernel_image])
        if self._kernel_command_line:
            options.extend(["-append", self._kernel_command_line])

        return options

    async def _network_options(self):

        network_options = []
        network_options.extend(["-net", "none"])  # we do not want any user networking back-end if no adapter is connected.

        patched_qemu = False
        if self._legacy_networking:
            version = await self.manager.get_qemu_version(self.qemu_path)
            if version and parse_version(version) < parse_version("1.1.0"):
                # this is a patched Qemu if version is below 1.1.0
                patched_qemu = True

        # Each 32 PCI device we need to add a PCI bridge with max 9 bridges
        pci_devices = 4 + len(self._ethernet_adapters)  # 4 PCI devices are use by default by qemu
        bridge_id = 0
        for bridge_id in range(1, math.floor(pci_devices / 32) + 1):
            network_options.extend(["-device", "i82801b11-bridge,id=dmi_pci_bridge{bridge_id}".format(bridge_id=bridge_id)])
            network_options.extend(["-device", "pci-bridge,id=pci-bridge{bridge_id},bus=dmi_pci_bridge{bridge_id},chassis_nr=0x1,addr=0x{bridge_id},shpc=off".format(bridge_id=bridge_id)])

        if bridge_id > 1:
            qemu_version = await self.manager.get_qemu_version(self.qemu_path)
            if qemu_version and parse_version(qemu_version) < parse_version("2.4.0"):
                raise QemuError("Qemu version 2.4 or later is required to run this VM with a large number of network adapters")

        pci_device_id = 4 + bridge_id  # Bridge consume PCI ports

        for adapter_number, adapter in enumerate(self._ethernet_adapters):
            mac = int_to_macaddress(macaddress_to_int(self._mac_address) + adapter_number)

            # use a local UDP tunnel to connect to uBridge instead
            if adapter_number not in self._local_udp_tunnels:
                self._local_udp_tunnels[adapter_number] = self._create_local_udp_tunnel()
            nio = self._local_udp_tunnels[adapter_number][0]

            custom_adapter = self._get_custom_adapter_settings(adapter_number)
            adapter_type = custom_adapter.get("adapter_type", self._adapter_type)
            custom_mac_address = custom_adapter.get("mac_address")
            if custom_mac_address:
                mac = int_to_macaddress(macaddress_to_int(custom_mac_address))

            if self._legacy_networking:
                # legacy QEMU networking syntax (-net)
                if nio:
                    network_options.extend(["-net", "nic,vlan={},macaddr={},model={}".format(adapter_number, mac, adapter_type)])
                    if isinstance(nio, NIOUDP):
                        if patched_qemu:
                            # use patched Qemu syntax
                            network_options.extend(["-net", "udp,vlan={},name=gns3-{},sport={},dport={},daddr={}".format(adapter_number,
                                                                                                                         adapter_number,
                                                                                                                         nio.lport,
                                                                                                                         nio.rport,
                                                                                                                         nio.rhost)])
                        else:
                            # use UDP tunnel support added in Qemu 1.1.0
                            network_options.extend(["-net", "socket,vlan={},name=gns3-{},udp={}:{},localaddr={}:{}".format(adapter_number,
                                                                                                                           adapter_number,
                                                                                                                           nio.rhost,
                                                                                                                           nio.rport,
                                                                                                                           "127.0.0.1",
                                                                                                                           nio.lport)])
                    elif isinstance(nio, NIOTAP):
                        network_options.extend(["-net", "tap,name=gns3-{},ifname={}".format(adapter_number, nio.tap_device)])
                else:
                    network_options.extend(["-net", "nic,vlan={},macaddr={},model={}".format(adapter_number, mac, adapter_type)])

            else:
                # newer QEMU networking syntax
                device_string = "{},mac={}".format(adapter_type, mac)
                bridge_id = math.floor(pci_device_id / 32)
                if bridge_id > 0:
                    addr = pci_device_id % 32
                    device_string = "{},bus=pci-bridge{bridge_id},addr=0x{addr:02x}".format(device_string, bridge_id=bridge_id, addr=addr)
                pci_device_id += 1
                if nio:
                    network_options.extend(["-device", "{},netdev=gns3-{}".format(device_string, adapter_number)])
                    if isinstance(nio, NIOUDP):
                        network_options.extend(["-netdev", "socket,id=gns3-{},udp={}:{},localaddr={}:{}".format(adapter_number,
                                                                                                                nio.rhost,
                                                                                                                nio.rport,
                                                                                                                "127.0.0.1",
                                                                                                                nio.lport)])
                    elif isinstance(nio, NIOTAP):
                        network_options.extend(["-netdev", "tap,id=gns3-{},ifname={},script=no,downscript=no".format(adapter_number, nio.tap_device)])
                else:
                    network_options.extend(["-device", device_string])

        return network_options

    async def _disable_graphics(self):
        """
        Disable graphics depending of the QEMU version
        """

        if any(opt in self._options for opt in ["-display", "-nographic", "-curses", "-sdl" "-spice", "-vnc"]):
            return []
        version = await self.manager.get_qemu_version(self.qemu_path)
        if version and parse_version(version) >= parse_version("3.0"):
            return ["-display", "none"]
        else:
            return ["-nographic"]

    async def _run_with_hardware_acceleration(self, qemu_path, options):
        """
        Check if we can run Qemu with hardware acceleration

        :param qemu_path: Path to qemu
        :param options: String of qemu user options
        :returns: Boolean True if we need to enable hardware acceleration
        """

        enable_hardware_accel = self.manager.config.get_section_config("Qemu").getboolean("enable_hardware_acceleration", True)
        require_hardware_accel = self.manager.config.get_section_config("Qemu").getboolean("require_hardware_acceleration", True)
        if sys.platform.startswith("linux"):
            # compatibility: these options were used before version 2.0 and have priority
            enable_kvm = self.manager.config.get_section_config("Qemu").getboolean("enable_kvm")
            if enable_kvm is not None:
                enable_hardware_accel = enable_kvm
            require_kvm = self.manager.config.get_section_config("Qemu").getboolean("require_kvm")
            if require_kvm is not None:
                require_hardware_accel = require_kvm

        if enable_hardware_accel and "-no-kvm" not in options and "-no-hax" not in options:
            # Turn OFF hardware acceleration for non x86 architectures
            if sys.platform.startswith("win"):
                supported_binaries = ["qemu-system-x86_64.exe", "qemu-system-x86_64w.exe", "qemu-system-i386.exe", "qemu-system-i386w.exe"]
            else:
                supported_binaries = ["qemu-system-x86_64", "qemu-system-i386", "qemu-kvm"]
            if os.path.basename(qemu_path) not in supported_binaries:
                if require_hardware_accel:
                    raise QemuError("Hardware acceleration can only be used with the following Qemu executables: {}".format(", ".join(supported_binaries)))
                else:
                    return False

            if sys.platform.startswith("linux") and not os.path.exists("/dev/kvm"):
                if require_hardware_accel:
                    raise QemuError("KVM acceleration cannot be used (/dev/kvm doesn't exist). It is possible to turn off KVM support in the gns3_server.conf by adding enable_kvm = false to the [Qemu] section.")
                else:
                    return False
            elif sys.platform.startswith("win"):
                if require_hardware_accel:
                    # HAXM is only available starting with Qemu version 2.9.0
                    version = await self.manager.get_qemu_version(self.qemu_path)
                    if version and parse_version(version) < parse_version("2.9.0"):
                        raise QemuError("HAXM acceleration can only be enable for Qemu version 2.9.0 and above (current version: {})".format(version))

                    # check if HAXM is installed
                    version = self.manager.get_haxm_windows_version()
                    if version is None:
                        raise QemuError("HAXM acceleration support is not installed on this host")
                    log.info("HAXM support version {} detected".format(version))

                    # check if the HAXM service is running
                    from gns3server.utils.windows_service import check_windows_service_is_running
                    if not check_windows_service_is_running("intelhaxm"):
                        raise QemuError("Intel HAXM service is not running on this host")

                else:
                    return False
            elif sys.platform.startswith("darwin"):
                process = await asyncio.create_subprocess_shell("kextstat | grep com.intel.kext.intelhaxm")
                await process.wait()
                if process.returncode != 0:
                    if require_hardware_accel:
                        raise QemuError("HAXM acceleration support is not installed on this host (com.intel.kext.intelhaxm extension not loaded)")
                    else:
                        return False
            return True
        return False

    async def _clear_save_vm_stated(self, snapshot_name="GNS3_SAVED_STATE"):

        drives = ["a", "b", "c", "d"]
        qemu_img_path = self._get_qemu_img()
        for disk_index, drive in enumerate(drives):
            disk_image = getattr(self, "_hd{}_disk_image".format(drive))
            if not disk_image:
                continue
            try:
                if self.linked_clone:
                    disk = os.path.join(self.working_dir, "hd{}_disk.qcow2".format(drive))
                else:
                    disk = disk_image
                if not os.path.exists(disk):
                    continue
                output = await subprocess_check_output(qemu_img_path, "info", "--output=json", disk)
                if output:
                    try:
                        json_data = json.loads(output)
                    except ValueError as e:
                        raise QemuError("Invalid JSON data returned by qemu-img while looking for the Qemu VM saved state snapshot: {}".format(e))
                    if "snapshots" in json_data:
                        for snapshot in json_data["snapshots"]:
                            if snapshot["name"] == snapshot_name:
                                # delete the snapshot
                                command = [qemu_img_path, "snapshot", "-d", snapshot_name, disk]
                                retcode = await self._qemu_img_exec(command)
                                if retcode:
                                    stdout = self.read_qemu_img_stdout()
                                    log.warning("Could not delete saved VM state from disk {}: {}".format(disk, stdout))
                                else:
                                    log.info("Deleted saved VM state from disk {}".format(disk))
            except subprocess.SubprocessError as e:
                raise QemuError("Error while looking for the Qemu VM saved state snapshot: {}".format(e))

    async def _saved_state_option(self, snapshot_name="GNS3_SAVED_STATE"):

        drives = ["a", "b", "c", "d"]
        qemu_img_path = self._get_qemu_img()
        for disk_index, drive in enumerate(drives):
            disk_image = getattr(self, "_hd{}_disk_image".format(drive))
            if not disk_image:
                continue
            try:
                if self.linked_clone:
                    disk = os.path.join(self.working_dir, "hd{}_disk.qcow2".format(drive))
                else:
                    disk = disk_image
                if not os.path.exists(disk):
                    continue
                output = await subprocess_check_output(qemu_img_path, "info", "--output=json", disk)
                if output:
                    try:
                        json_data = json.loads(output)
                    except ValueError as e:
                        raise QemuError("Invalid JSON data returned by qemu-img while looking for the Qemu VM saved state snapshot: {}".format(e))
                    if "snapshots" in json_data:
                        for snapshot in json_data["snapshots"]:
                            if snapshot["name"] == snapshot_name:
                                log.info('QEMU VM "{name}" [{id}] VM saved state detected (snapshot name: {snapshot})'.format(name=self._name,
                                                                                                                              id=self.id,
                                                                                                                              snapshot=snapshot_name))
                                return ["-loadvm", snapshot_name]

            except subprocess.SubprocessError as e:
                raise QemuError("Error while looking for the Qemu VM saved state snapshot: {}".format(e))
        return []

    async def _build_command(self):
        """
        Command to start the QEMU process.
        (to be passed to subprocess.Popen())
        """

        additional_options = self._options.strip()
        additional_options = additional_options.replace("%vm-name%", '"' + self._name.replace('"', '\\"') + '"')
        additional_options = additional_options.replace("%vm-id%", self._id)
        additional_options = additional_options.replace("%project-id%", self.project.id)
        additional_options = additional_options.replace("%project-path%", '"' + self.project.path.replace('"', '\\"') + '"')
        additional_options = additional_options.replace("%guest-cid%", str(self._guest_cid))
        if self._console_type != "none" and self._console:
            additional_options = additional_options.replace("%console-port%", str(self._console))
        command = [self.qemu_path]
        command.extend(["-name", self._name])
        command.extend(["-m", "{}M".format(self._ram)])
        command.extend(["-smp", "cpus={}".format(self._cpus)])
        if (await self._run_with_hardware_acceleration(self.qemu_path, self._options)):
            if sys.platform.startswith("linux"):
                command.extend(["-enable-kvm"])
                version = await self.manager.get_qemu_version(self.qemu_path)
                # Issue on some combo Intel CPU + KVM + Qemu 2.4.0
                # https://github.com/GNS3/gns3-server/issues/685
                if version and parse_version(version) >= parse_version("2.4.0") and self.platform == "x86_64":
                    command.extend(["-machine", "smm=off"])
            elif sys.platform.startswith("win") or sys.platform.startswith("darwin"):
                command.extend(["-enable-hax"])
        command.extend(["-boot", "order={}".format(self._boot_priority)])
        command.extend(self._bios_option())
        command.extend(self._cdrom_option())
        command.extend((await self._disk_options()))
        command.extend(self._linux_boot_options())
        if "-uuid" not in additional_options:
            command.extend(["-uuid", self._id])
        if self._console_type == "telnet":
            command.extend(self._serial_options())
        elif self._console_type == "vnc":
            command.extend(self._vnc_options())
        elif self._console_type == "spice":
            command.extend(self._spice_options())
        elif self._console_type == "spice+agent":
            command.extend(self._spice_with_agent_options())
        elif self._console_type != "none":
            raise QemuError("Console type {} is unknown".format(self._console_type))
        command.extend(self._monitor_options())
        command.extend((await self._network_options()))
        if self.on_close != "save_vm_state":
            await self._clear_save_vm_stated()
        else:
            command.extend((await self._saved_state_option()))
        if self._console_type == "telnet":
            command.extend((await self._disable_graphics()))
        if additional_options:
            try:
                command.extend(shlex.split(additional_options))
            except ValueError as e:
                raise QemuError("Invalid additional options: {} error {}".format(additional_options, e))
        return command

    def __json__(self):
        answer = {
            "project_id": self.project.id,
            "node_id": self.id,
            "node_directory": self.working_path
        }
        # Qemu has a long list of options. The JSON schema is the single source of information
        for field in QEMU_OBJECT_SCHEMA["required"]:
            if field not in answer:
                try:
                    answer[field] = getattr(self, field)
                except AttributeError:
                    pass
        answer["hda_disk_image"] = self.manager.get_relative_image_path(self._hda_disk_image, self.project.path)
        answer["hda_disk_image_md5sum"] = md5sum(self._hda_disk_image)
        answer["hdb_disk_image"] = self.manager.get_relative_image_path(self._hdb_disk_image, self.project.path)
        answer["hdb_disk_image_md5sum"] = md5sum(self._hdb_disk_image)
        answer["hdc_disk_image"] = self.manager.get_relative_image_path(self._hdc_disk_image, self.project.path)
        answer["hdc_disk_image_md5sum"] = md5sum(self._hdc_disk_image)
        answer["hdd_disk_image"] = self.manager.get_relative_image_path(self._hdd_disk_image, self.project.path)
        answer["hdd_disk_image_md5sum"] = md5sum(self._hdd_disk_image)
        answer["cdrom_image"] = self.manager.get_relative_image_path(self._cdrom_image, self.project.path)
        answer["cdrom_image_md5sum"] = md5sum(self._cdrom_image)
        answer["bios_image"] = self.manager.get_relative_image_path(self._bios_image, self.project.path)
        answer["bios_image_md5sum"] = md5sum(self._bios_image)
        answer["initrd"] = self.manager.get_relative_image_path(self._initrd, self.project.path)
        answer["initrd_md5sum"] = md5sum(self._initrd)
        answer["kernel_image"] = self.manager.get_relative_image_path(self._kernel_image, self.project.path)
        answer["kernel_image_md5sum"] = md5sum(self._kernel_image)
        return answer