path: root/resources/libraries/python/QemuUtils.py

# Copyright (c) 2018 Cisco and/or its affiliates.
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at:
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

"""QEMU utilities library."""

from time import time, sleep
import json
import re
# Disable due to pylint bug
# pylint: disable=no-name-in-module,import-error
from distutils.version import StrictVersion

from robot.api import logger

from resources.libraries.python.ssh import SSH, SSHTimeout
from resources.libraries.python.constants import Constants
from resources.libraries.python.DUTSetup import DUTSetup
from resources.libraries.python.topology import NodeType, Topology


class QemuUtils(object):
    """QEMU utilities."""

    def __init__(self, qemu_id=1):
        self._qemu_id = qemu_id
        self._vhost_id = 0
        self._ssh = None
        self._node = None
        # Qemu Options
        self._qemu_opt = {}
        # Path to QEMU binary. Use x86_64 by default
        self._qemu_opt['qemu_path'] = '/usr/bin/'
        self._qemu_opt['qemu_bin'] = 'qemu-system-x86_64'
        # QEMU Machine Protocol socket
        self._qemu_opt['qmp_sock'] = '/tmp/qmp{0}.sock'.format(self._qemu_id)
        # QEMU Guest Agent socket
        self._qemu_opt['qga_sock'] = '/tmp/qga{0}.sock'.format(self._qemu_id)
        # QEMU PID file
        self._qemu_opt['pid_file'] = '/tmp/qemu{0}.pid'.format(self._qemu_id)
        # Default 1 CPU.
        self._qemu_opt['smp'] = '-smp 1,sockets=1,cores=1,threads=1'
        # Daemonize the QEMU process after initialization. Default one
        # management interface.
        self._qemu_opt['options'] = '-cpu host -daemonize -enable-kvm ' \
            '-machine pc,accel=kvm,usb=off,mem-merge=off ' \
            '-net nic,macaddr=52:54:00:00:{0:02x}:ff -balloon none'\
            .format(self._qemu_id)
        self._qemu_opt['ssh_fwd_port'] = 10021 + qemu_id
        # Default serial console port
        self._qemu_opt['serial_port'] = 4555 + qemu_id
        # Default 512MB virtual RAM
        self._qemu_opt['mem_size'] = 512
        # Default huge page mount point, required for Vhost-user interfaces.
        self._qemu_opt['huge_mnt'] = '/mnt/huge'
        # Default do not allocate huge pages.
        self._qemu_opt['huge_allocate'] = False
        # Default image for CSIT virl setup
        self._qemu_opt['disk_image'] = '/var/lib/vm/vhost-nested.img'
        # Virtio queue count
        self._qemu_opt['queue_count'] = 1
        # Virtio queue size
        self._qemu_opt['queue_size'] = None
        # VM node info dict
        self._vm_info = {
            'type': NodeType.VM,
            'port': self._qemu_opt['ssh_fwd_port'],
            'username': 'cisco',
            'password': 'cisco',
            'interfaces': {},
        }
        # Qemu Sockets
        self._socks = [self._qemu_opt.get('qmp_sock'),
                       self._qemu_opt.get('qga_sock')]

    def qemu_set_path(self, path):
        """Set binary path for QEMU.

        :param path: Absolute path in filesystem.
        :type path: str
        """
        self._qemu_opt['qemu_path'] = path

    def qemu_set_queue_count(self, count):
        """Set number of virtio queues.

        :param count: Number of virtio queues.
        :type count: int
        """
        self._qemu_opt['queue_count'] = int(count)

    def qemu_set_queue_size(self, size):
        """Set RX/TX size of virtio queues.

        :param size: Size of virtio queues.
        :type size: int
        """
        self._qemu_opt['queue_size'] = int(size)

    def qemu_set_smp(self, smp, cores, threads, sockets):
        """Set SMP option for QEMU.

        :param smp: Number of CPUs.
        :param cores: Number of CPU cores on one socket.
        :param threads: Number of threads on one CPU core.
        :param sockets: Number of discrete sockets in the system.
        :type smp: int
        :type cores: int
        :type threads: int
        :type sockets: int
        """
        self._qemu_opt['smp'] = \
            ('-smp {smp},cores={cores},threads={threads},sockets={sockets}'.
             format(smp=smp, cores=cores, threads=threads, sockets=sockets))

    def qemu_set_ssh_fwd_port(self, fwd_port):
        """Set host port for guest SSH forwarding.

        :param fwd_port: Port number on host for guest SSH forwarding.
        :type fwd_port: int
        """
        self._qemu_opt['ssh_fwd_port'] = fwd_port
        self._vm_info['port'] = fwd_port

    def qemu_set_serial_port(self, port):
        """Set serial console port.

        :param port: Serial console port.
        :type port: int
        """
        self._qemu_opt['serial_port'] = port

    def qemu_set_mem_size(self, mem_size):
        """Set virtual RAM size.

        :param mem_size: RAM size in Mega Bytes.
        :type mem_size: int
        """
        self._qemu_opt['mem_size'] = int(mem_size)

    def qemu_set_huge_mnt(self, huge_mnt):
        """Set hugefile mount point.

        :param huge_mnt: System hugefile mount point.
        :type huge_mnt: int
        """
        self._qemu_opt['huge_mnt'] = huge_mnt

    def qemu_set_huge_allocate(self):
        """Set flag to allocate more huge pages if needed."""
        self._qemu_opt['huge_allocate'] = True

    def qemu_set_disk_image(self, disk_image):
        """Set disk image.

        :param disk_image: Path of the disk image.
        :type disk_image: str
        """
        self._qemu_opt['disk_image'] = disk_image

    def qemu_set_affinity(self, *host_cpus):
        """Set qemu affinity by getting thread PIDs via QMP and taskset to list
        of CPU cores.

        :param host_cpus: List of CPU cores.
        :type host_cpus: list
        """
        qemu_cpus = self._qemu_qmp_exec('query-cpus')['return']

        if len(qemu_cpus) != len(host_cpus):
            raise ValueError('Host CPU count must match Qemu Thread count')

        for qemu_cpu, host_cpu in zip(qemu_cpus, host_cpus):
            ret_code, _, _ = self._ssh.exec_command_sudo(
                'taskset -pc {host_cpu} {thread_id}'.
                format(host_cpu=host_cpu, thread_id=qemu_cpu['thread_id']))
            if int(ret_code) != 0:
                raise RuntimeError('Set affinity failed on {host}'.
                                   format(host=self._node['host']))

    def qemu_set_scheduler_policy(self):
        """Set scheduler policy to SCHED_RR with priority 1 for all Qemu CPU
        processes.

        :raises RuntimeError: Set scheduler policy failed.
        """
        qemu_cpus = self._qemu_qmp_exec('query-cpus')['return']

        for qemu_cpu in qemu_cpus:
            ret_code, _, _ = self._ssh.exec_command_sudo(
                'chrt -r -p 1 {thread_id}'.
                format(thread_id=qemu_cpu['thread_id']))
            if int(ret_code) != 0:
                raise RuntimeError('Set SCHED_RR failed on {host}'.
                                   format(host=self._node['host']))

    def qemu_set_node(self, node):
        """Set node to run QEMU on.

        :param node: Node to run QEMU on.
        :type node: dict
        """
        self._node = node
        self._ssh = SSH()
        self._ssh.connect(node)
        self._vm_info['host'] = node['host']

        arch = Topology.get_node_arch(node)
        self._qemu_opt['qemu_bin'] = 'qemu-system-{arch}'.format(arch=arch)

    def qemu_add_vhost_user_if(self, socket, server=True, mac=None,
                               jumbo_frames=False):
        """Add Vhost-user interface.

        :param socket: Path of the unix socket.
        :param server: If True the socket shall be a listening socket.
        :param mac: Vhost-user interface MAC address (optional, otherwise is
            used auto-generated MAC 52:54:00:00:xx:yy).
        :param jumbo_frames: Set True if jumbo frames are used in the test.
        :type socket: str
        :type server: bool
        :type mac: str
        :type jumbo_frames: bool
        """
        self._vhost_id += 1
        # Create unix socket character device.
        chardev = (' -chardev socket,id=char{vhost_id},path={socket}{server}'.
                   format(vhost_id=self._vhost_id,
                          socket=socket,
                          server=',server' if server is True else ''))
        self._qemu_opt['options'] += chardev
        # Create Vhost-user network backend.
        netdev = (' -netdev vhost-user,id=vhost{vhost_id},'
                  'chardev=char{vhost_id},queues={queue_count}'.
                  format(vhost_id=self._vhost_id,
                         queue_count=self._qemu_opt.get('queue_count')))
        self._qemu_opt['options'] += netdev
        # If MAC is not specified use auto-generated MAC address based on
        # template 52:54:00:00:<qemu_id>:<vhost_id>, e.g. vhost1 MAC of QEMU
        #  with ID 1 is 52:54:00:00:01:01
        mac = ('52:54:00:00:{qemu_id:02x}:{vhost_id:02x}'.
               format(qemu_id=self._qemu_id, vhost_id=self._vhost_id))\
            if mac is None else mac

        queue_size = (',rx_queue_size={queue_size},tx_queue_size={queue_size}'.
                      format(queue_size=self._qemu_opt.get('queue_size')))\
            if self._qemu_opt.get('queue_size') else ''

        # Create Virtio network device.
        device = (' -device virtio-net-pci,netdev=vhost{vhost_id},mac={mac},'
                  'mq=on,csum=off,gso=off,guest_tso4=off,guest_tso6=off,'
                  'guest_ecn=off,mrg_rxbuf={mbuf}{queue_size}'.
                  format(vhost_id=self._vhost_id, mac=mac,
                         mbuf='on' if jumbo_frames else 'off',
                         queue_size=queue_size))
        self._qemu_opt['options'] += device
        # Add interface MAC and socket to the node dict
        if_data = {'mac_address': mac, 'socket': socket}
        if_name = 'vhost{vhost_id}'.format(vhost_id=self._vhost_id)
        self._vm_info['interfaces'][if_name] = if_data
        # Add socket to the socket list
        self._socks.append(socket)

    def _qemu_qmp_exec(self, cmd):
        """Execute QMP command.

        QMP is JSON based protocol which allows to control QEMU instance.

        :param cmd: QMP command to execute.
        :type cmd: str
        :returns: Command output in python representation of JSON format. The
            { "return": {} } response is QMP's success response. An error
            response will contain the "error" keyword instead of "return".
        """
        # To enter command mode, the qmp_capabilities command must be issued.
        ret_code, stdout, _ = self._ssh.exec_command(
            'echo "{{ \\"execute\\": \\"qmp_capabilities\\" }}'
            '{{ \\"execute\\": \\"{cmd}\\" }}" | '
            'sudo -S socat - UNIX-CONNECT:{qmp_sock}'.
            format(cmd=cmd, qmp_sock=self._qemu_opt.get('qmp_sock')))
        if int(ret_code) != 0:
            raise RuntimeError('QMP execute "{cmd}" failed on {host}'.
                               format(cmd=cmd, host=self._node['host']))
        # Skip capabilities negotiation messages.
        out_list = stdout.splitlines()
        if len(out_list) < 3:
            raise RuntimeError('Invalid QMP output on {host}'.
                               format(host=self._node['host']))
        return json.loads(out_list[2])

    def _qemu_qga_flush(self):
        """Flush the QGA parser state."""
        ret_code, stdout, _ = self._ssh.exec_command(
            '(printf "\xFF"; sleep 1) | '
            'sudo -S socat - UNIX-CONNECT:{qga_sock}'.
            format(qga_sock=self._qemu_opt.get('qga_sock')))
        if int(ret_code) != 0:
            raise RuntimeError('QGA flush failed on {host}'.
                               format(host=self._node['host']))
        if not stdout:
            return {}
        return json.loads(stdout.split('\n', 1)[0])

    def _qemu_qga_exec(self, cmd):
        """Execute QGA command.

        QGA provide access to a system-level agent via standard QMP commands.

        :param cmd: QGA command to execute.
        :type cmd: str
        """
        ret_code, stdout, _ = self._ssh.exec_command(
            '(echo "{{ \\"execute\\": \\"{cmd}\\" }}"; sleep 1) | '
            'sudo -S socat - UNIX-CONNECT:{qga_sock}'.
            format(cmd=cmd, qga_sock=self._qemu_opt.get('qga_sock')))
        if int(ret_code) != 0:
            raise RuntimeError('QGA execute "{cmd}" failed on {host}'.
                               format(cmd=cmd, host=self._node['host']))
        if not stdout:
            return {}
        return json.loads(stdout.split('\n', 1)[0])

    def _wait_until_vm_boot(self, timeout=60):
        """Wait until QEMU VM is booted.

        First try to flush qga until there is output.
        Then ping QEMU guest agent each 5s until VM booted or timeout.

        :param timeout: Waiting timeout in seconds (optional, default 60s).
        :type timeout: int
        """
        start = time()
        while True:
            if time() - start > timeout:
                raise RuntimeError('timeout, VM {disk} not booted on {host}'.
                                   format(disk=self._qemu_opt['disk_image'],
                                          host=self._node['host']))
            out = None
            try:
                out = self._qemu_qga_flush()
            except ValueError:
                logger.trace('QGA qga flush unexpected output {out}'.
                             format(out=out))
            # Empty output - VM not booted yet
            if not out:
                sleep(5)
            else:
                break
        while True:
            if time() - start > timeout:
                raise RuntimeError('timeout, VM with {disk} not booted '
                                   'on {host}'.
                                   format(disk=self._qemu_opt['disk_image'],
                                          host=self._node['host']))
            out = None
            try:
                out = self._qemu_qga_exec('guest-ping')
            except ValueError:
                logger.trace('QGA guest-ping unexpected output {out}'.
                             format(out=out))
            # Empty output - VM not booted yet
            if not out:
                sleep(5)
            # Non-error return - VM booted
            elif out.get('return') is not None:
                break
            # Skip error and wait
            elif out.get('error') is not None:
                sleep(5)
            else:
                # If there is an unexpected output from QGA guest-info, try
                # again until timeout.
                logger.trace('QGA guest-ping unexpected output {out}'.
                             format(out=out))

        logger.trace('VM with {disk_image} booted on {host}'.
                     format(disk_image=self._qemu_opt['disk_image'],
                            host=self._node['host']))

    def _update_vm_interfaces(self):
        """Update interface names in VM node dict."""
        # Send guest-network-get-interfaces command via QGA, output example:
        # {"return": [{"name": "eth0", "hardware-address": "52:54:00:00:04:01"},
        # {"name": "eth1", "hardware-address": "52:54:00:00:04:02"}]}
        out = self._qemu_qga_exec('guest-network-get-interfaces')
        interfaces = out.get('return')
        mac_name = {}
        if not interfaces:
            raise RuntimeError('Get VM {disk_image} interface list failed '
                               'on {host}'.
                               format(disk_image=self._qemu_opt['disk_image'],
                                      host=self._node['host']))
        # Create MAC-name dict
        for interface in interfaces:
            if 'hardware-address' not in interface:
                continue
            mac_name[interface['hardware-address']] = interface['name']
        # Match interface by MAC and save interface name
        for interface in self._vm_info['interfaces'].values():
            mac = interface.get('mac_address')
            if_name = mac_name.get(mac)
            if if_name is None:
                logger.trace('Interface name for MAC {mac} not found'.
                             format(mac=mac))
            else:
                interface['name'] = if_name

    def qemu_start(self):
        """Start QEMU and wait until VM boot.

        .. note:: First set at least node to run QEMU on.

        :returns: VM node info.
        :rtype: dict
        """
        # Qemu binary path
        bin_path = ('{qemu_path}{qemu_bin}'.
                    format(qemu_path=self._qemu_opt.get('qemu_path'),
                           qemu_bin=self._qemu_opt.get('qemu_bin')))

        # Memory and huge pages
        mem = ('-object memory-backend-file,id=mem,size={mem_size}M,'
               'mem-path={path},share=on -m {mem_size} -numa node,memdev=mem'.
               format(mem_size=self._qemu_opt.get('mem_size'),
                      path=self._qemu_opt.get('huge_mnt')))

        # Drive option
        drive = ('-drive file={disk_image},format=raw,cache=none,if=virtio'
                 '{locking}'.
                 format(disk_image=self._qemu_opt.get('disk_image'),
                        locking=',file.locking=off'\
                            if self._qemu_version_is_greater('2.10') else ''))

        # SSH forwarding
        ssh = ('-net user,hostfwd=tcp::{ssh_fwd_port}-:22'.
               format(ssh_fwd_port=self._qemu_opt.get('ssh_fwd_port')))
        # Setup QMP via unix socket
        qmp = ('-qmp unix:{qmp_sock},server,nowait'.
               format(qmp_sock=self._qemu_opt.get('qmp_sock')))
        # Setup QGA via chardev (unix socket) and isa-serial channel
        qga = ('-chardev socket,path={qga_sock},server,nowait,id=qga0 '
               '-device isa-serial,chardev=qga0'.
               format(qga_sock=self._qemu_opt.get('qga_sock')))
        # Setup serial console
        serial = ('-chardev socket,host=127.0.0.1,port={serial_port},id=gnc0,'
                  'server,nowait -device isa-serial,chardev=gnc0'.
                  format(serial_port=self._qemu_opt.get('serial_port')))

        # Graphic setup
        graphic = '-monitor none -display none -vga none'

        # PID file
        pid = ('-pidfile {pid_file}'.
               format(pid_file=self._qemu_opt.get('pid_file')))

        # By default check only if hugepages are available.
        # If 'huge_allocate' is set to true try to allocate as well.
        DUTSetup.check_huge_page(self._node, self._qemu_opt.get('huge_mnt'),
                                 self._qemu_opt.get('mem_size'),
                                 allocate=self._qemu_opt.get('huge_allocate'))

        # Run QEMU
        cmd = ('{bin_path} {smp} {mem} {ssh} {options} {drive} {qmp} {serial} '
               '{qga} {graphic} {pid}'.
               format(bin_path=bin_path, smp=self._qemu_opt.get('smp'),
                      mem=mem, ssh=ssh, options=self._qemu_opt.get('options'),
                      drive=drive, qmp=qmp, serial=serial, qga=qga,
                      graphic=graphic, pid=pid))
        try:
            ret_code, _, _ = self._ssh.exec_command_sudo(cmd, timeout=300)
            if int(ret_code) != 0:
                raise RuntimeError('QEMU start failed on {host}'.
                                   format(host=self._node['host']))
            # Wait until VM boot
            self._wait_until_vm_boot()
        except (RuntimeError, SSHTimeout):
            self.qemu_kill_all()
            self.qemu_clear_socks()
            raise
        logger.trace('QEMU started successfully.')
        # Update interface names in VM node dict
        self._update_vm_interfaces()
        # Return VM node dict
        return self._vm_info

    def qemu_quit(self):
        """Quit the QEMU emulator."""
        out = self._qemu_qmp_exec('quit')
        err = out.get('error')
        if err is not None:
            raise RuntimeError('QEMU quit failed on {host}: {error}'.
                               format(host=self._node['host'],
                                      error=json.dumps(err)))

    def qemu_system_powerdown(self):
        """Power down the system (if supported)."""
        out = self._qemu_qmp_exec('system_powerdown')
        err = out.get('error')
        if err is not None:
            raise RuntimeError(
                'QEMU system powerdown failed on {host}: {error}'.
                format(host=self._node['host'], error=json.dumps(err)))

    def qemu_system_reset(self):
        """Reset the system."""
        out = self._qemu_qmp_exec('system_reset')
        err = out.get('error')
        if err is not None:
            raise RuntimeError(
                'QEMU system reset failed on {host}: {error}'.
                format(host=self._node['host'], error=json.dumps(err)))

    def qemu_kill(self):
        """Kill qemu process."""
        # Note: in QEMU start phase there are 3 QEMU processes because we
        # daemonize QEMU
        self._ssh.exec_command_sudo('chmod +r {pid}'.
                                    format(pid=self._qemu_opt.get('pid_file')))
        self._ssh.exec_command_sudo('kill -SIGKILL $(cat {pid})'.
                                    format(pid=self._qemu_opt.get('pid_file')))
        # Delete PID file
        self._ssh.exec_command_sudo('rm -f {pid}'.
                                    format(pid=self._qemu_opt.get('pid_file')))

    def qemu_kill_all(self, node=None):
        """Kill all qemu processes on DUT node if specified.

        :param node: Node to kill all QEMU processes on.
        :type node: dict
        """
        if node:
            self.qemu_set_node(node)
        self._ssh.exec_command_sudo('pkill -SIGKILL qemu')

    def qemu_clear_socks(self):
        """Remove all sockets created by QEMU."""
        # If serial console port still open kill process
        self._ssh.exec_command_sudo('fuser -k {serial_port}/tcp'.
                                    format(serial_port=\
                                           self._qemu_opt.get('serial_port')))
        # Delete all created sockets
        for socket in self._socks:
            self._ssh.exec_command_sudo('rm -f {socket}'.
                                        format(socket=socket))

    def qemu_system_status(self):
        """Return current VM status.

        VM should be in following status:

            - debug: QEMU running on a debugger
            - finish-migrate: paused to finish the migration process
            - inmigrate: waiting for an incoming migration
            - internal-error: internal error has occurred
            - io-error: the last IOP has failed
            - paused: paused
            - postmigrate: paused following a successful migrate
            - prelaunch: QEMU was started with -S and guest has not started
            - restore-vm: paused to restore VM state
            - running: actively running
            - save-vm: paused to save the VM state
            - shutdown: shut down (and -no-shutdown is in use)
            - suspended: suspended (ACPI S3)
            - watchdog: watchdog action has been triggered
            - guest-panicked: panicked as a result of guest OS panic

        :returns: VM status.
        :rtype: str
        """
        out = self._qemu_qmp_exec('query-status')
        ret = out.get('return')
        if ret is not None:
            return ret.get('status')
        else:
            err = out.get('error')
            raise RuntimeError('QEMU query-status failed on {host}: {error}'.
                               format(host=self._node['host'],
                                      error=json.dumps(err)))

    def qemu_version(self):
        """Return Qemu version.

        :returns: Qemu version.
        :rtype: str
        """
        # Qemu binary path
        bin_path = ('{qemu_path}{qemu_bin}'.
                    format(qemu_path=self._qemu_opt.get('qemu_path'),
                           qemu_bin=self._qemu_opt.get('qemu_bin')))

        try:
            ret_code, stdout, _ = self._ssh.exec_command_sudo(
                '{bin_path} --version'.
                format(bin_path=bin_path))
            if int(ret_code) != 0:
                raise RuntimeError('Failed to get QEMU version on {host}'.
                                   format(host=self._node['host']))

            return re.match(r'QEMU emulator version ([\d.]*)', stdout).group(1)
        except (RuntimeError, SSHTimeout):
            self.qemu_kill_all()
            self.qemu_clear_socks()
            raise

    def _qemu_version_is_greater(self, version):
        """Compare Qemu versions.

        :returns: True if installed Qemu version is greater.
        :rtype: bool
        """
        return StrictVersion(self.qemu_version()) > StrictVersion(version)

    @staticmethod
    def build_qemu(node, force_install=False, apply_patch=False):
        """Build QEMU from sources.

        :param node: Node to build QEMU on.
        :param force_install: If True, then remove previous build.
        :param apply_patch: If True, then apply patches from qemu_patches dir.
        :type node: dict
        :type force_install: bool
        :type apply_patch: bool
        :raises RuntimeError: If building QEMU failed.
        """
        ssh = SSH()
        ssh.connect(node)

        directory = (' --directory={install_dir}{patch}'.
                     format(install_dir=Constants.QEMU_INSTALL_DIR,
                            patch='-patch' if apply_patch else '-base'))
        version = (' --version={install_version}'.
                   format(install_version=Constants.QEMU_INSTALL_VERSION))
        force = ' --force' if force_install else ''
        patch = ' --patch' if apply_patch else ''
        arch = Topology.get_node_arch(node)
        target_list = (' --target-list={arch}-softmmu'.
                       format(arch=arch))

        ret_code, _, _ = ssh.exec_command(
            "sudo -E sh -c '{fw_dir}/{lib_sh}/qemu_build.sh{version}{directory}"
            "{force}{patch}{target_list}'".
            format(fw_dir=Constants.REMOTE_FW_DIR,
                   lib_sh=Constants.RESOURCES_LIB_SH,
                   version=version, directory=directory, force=force,
                   patch=patch, target_list=target_list), 1000)

        if int(ret_code) != 0:
            raise RuntimeError('QEMU build failed on {host}'.
                               format(host=node['host']))