Use 'Qemu Kill All' in perf test teardown
[csit.git] / resources / libraries / python / QemuUtils.py
index c723878..cbdfe85 100644 (file)
 
 """QEMU utilities library."""
 
+from time import time, sleep
+import json
+
 from robot.api import logger
-from ssh import SSH
-from constants import Constants
+
+from resources.libraries.python.ssh import SSH, SSHTimeout
+from resources.libraries.python.constants import Constants
+from resources.libraries.python.topology import NodeType
 
 
 class QemuUtils(object):
     """QEMU utilities."""
 
+    def __init__(self, qemu_id=1):
+        self._qemu_id = qemu_id
+        # Path to QEMU binary
+        self._qemu_bin = '/usr/bin/qemu-system-x86_64'
+        # QEMU Machine Protocol socket
+        self._qmp_sock = '/tmp/qmp{0}.sock'.format(self._qemu_id)
+        # QEMU Guest Agent socket
+        self._qga_sock = '/tmp/qga{0}.sock'.format(self._qemu_id)
+        # QEMU PID file
+        self._pid_file = '/tmp/qemu{0}.pid'.format(self._qemu_id)
+        self._qemu_opt = {}
+        # 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'
+        # VM node info dict
+        self._vm_info = {
+            'type': NodeType.VM,
+            'port': self._qemu_opt['ssh_fwd_port'],
+            'username': 'cisco',
+            'password': 'cisco',
+            'interfaces': {},
+        }
+        # Virtio queue count
+        self._qemu_opt['queues'] = 1
+        self._vhost_id = 0
+        self._ssh = None
+        self._node = None
+        self._socks = [self._qmp_sock, self._qga_sock]
+
+    def qemu_set_bin(self, path):
+        """Set binary path for QEMU.
+
+        :param path: Absolute path in filesystem.
+        :type path: str
+        """
+        self._qemu_bin = path
+
+    def qemu_set_smp(self, cpus, cores, threads, sockets):
+        """Set SMP option for QEMU.
+
+        :param cpus: 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 cpus: int
+        :type cores: int
+        :type threads: int
+        :type sockets: int
+        """
+        self._qemu_opt['smp'] = '-smp {},cores={},threads={},sockets={}'.format(
+            cpus, cores, threads, 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):
+            logger.debug('Host CPU count {0}, Qemu Thread count {1}'.format(
+                len(host_cpus), len(qemu_cpus)))
+            raise ValueError('Host CPU count must match Qemu Thread count')
+
+        for qemu_cpu, host_cpu in zip(qemu_cpus, host_cpus):
+            cmd = 'taskset -pc {0} {1}'.format(host_cpu, qemu_cpu['thread_id'])
+            (ret_code, _, stderr) = self._ssh.exec_command_sudo(cmd)
+            if int(ret_code) != 0:
+                logger.debug('Set affinity failed {0}'.format(stderr))
+                raise RuntimeError('Set affinity failed on {0}'.format(
+                    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:
+            cmd = 'chrt -r -p 1 {0}'.format(qemu_cpu['thread_id'])
+            (ret_code, _, stderr) = self._ssh.exec_command_sudo(cmd)
+            if int(ret_code) != 0:
+                logger.debug('Set SCHED_RR failed {0}'.format(stderr))
+                raise RuntimeError('Set SCHED_RR failed on {0}'.format(
+                    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']
+
+    def qemu_add_vhost_user_if(self, socket, server=True, mac=None):
+        """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).
+        :type socket: str
+        :type server: bool
+        :type mac: str
+        """
+        self._vhost_id += 1
+        # Create unix socket character device.
+        chardev = ' -chardev socket,id=char{0},path={1}'.format(self._vhost_id,
+                                                                socket)
+        if server is True:
+            chardev += ',server'
+        self._qemu_opt['options'] += chardev
+        # Create Vhost-user network backend.
+        netdev = (' -netdev vhost-user,id=vhost{0},chardev=char{0},queues={1}'
+                  .format(self._vhost_id, self._qemu_opt['queues']))
+        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
+        if mac is None:
+            mac = '52:54:00:00:{0:02x}:{1:02x}'.\
+                format(self._qemu_id, self._vhost_id)
+        extend_options = 'mq=on,csum=off,gso=off,guest_tso4=off,'\
+            'guest_tso6=off,guest_ecn=off,mrg_rxbuf=off'
+        # Create Virtio network device.
+        device = ' -device virtio-net-pci,netdev=vhost{0},mac={1},{2}'.format(
+            self._vhost_id, mac, extend_options)
+        self._qemu_opt['options'] += device
+        # Add interface MAC and socket to the node dict
+        if_data = {'mac_address': mac, 'socket': socket}
+        if_name = 'vhost{}'.format(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
+        :return: 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.
+        qmp_cmd = 'echo "{ \\"execute\\": \\"qmp_capabilities\\" }' \
+                  '{ \\"execute\\": \\"' + cmd + \
+                  '\\" }" | sudo -S socat - UNIX-CONNECT:' + self._qmp_sock
+
+        (ret_code, stdout, stderr) = self._ssh.exec_command(qmp_cmd)
+        if int(ret_code) != 0:
+            logger.debug('QMP execute failed {0}'.format(stderr))
+            raise RuntimeError('QMP execute "{0}"'
+                               ' failed on {1}'.format(cmd, self._node['host']))
+        logger.trace(stdout)
+        # Skip capabilities negotiation messages.
+        out_list = stdout.splitlines()
+        if len(out_list) < 3:
+            raise RuntimeError('Invalid QMP output on {0}'.format(
+                self._node['host']))
+        return json.loads(out_list[2])
+
+    def _qemu_qga_flush(self):
+        """Flush the QGA parser state
+        """
+        qga_cmd = '(printf "\xFF"; sleep 1) | sudo -S socat - UNIX-CONNECT:' + \
+                  self._qga_sock
+        #TODO: probably need something else
+        (ret_code, stdout, stderr) = self._ssh.exec_command(qga_cmd)
+        if int(ret_code) != 0:
+            logger.debug('QGA execute failed {0}'.format(stderr))
+            raise RuntimeError('QGA execute "{0}" '
+                               'failed on {1}'.format(qga_cmd,
+                                                      self._node['host']))
+        logger.trace(stdout)
+        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
+        """
+        qga_cmd = '(echo "{ \\"execute\\": \\"' + \
+                  cmd + \
+                  '\\" }"; sleep 1) | sudo -S socat - UNIX-CONNECT:' + \
+                  self._qga_sock
+        (ret_code, stdout, stderr) = self._ssh.exec_command(qga_cmd)
+        if int(ret_code) != 0:
+            logger.debug('QGA execute failed {0}'.format(stderr))
+            raise RuntimeError('QGA execute "{0}"'
+                               ' failed on {1}'.format(cmd, self._node['host']))
+        logger.trace(stdout)
+        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.
+
+        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 {0} not booted on {1}'.format(
+                    self._qemu_opt['disk_image'], self._node['host']))
+            out = None
+            try:
+                self._qemu_qga_flush()
+                out = self._qemu_qga_exec('guest-ping')
+            except ValueError:
+                logger.trace('QGA guest-ping unexpected output {}'.format(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 {}'.format(out))
+
+        logger.trace('VM {0} booted on {1}'.format(self._qemu_opt['disk_image'],
+                                                   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 {0} interface list failed on {1}'.format(
+                self._qemu_opt['disk_image'], 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 {} not found'.format(mac))
+            else:
+                interface['name'] = if_name
+
+    def _huge_page_check(self, allocate=False):
+        """Huge page check."""
+        huge_mnt = self._qemu_opt.get('huge_mnt')
+        mem_size = self._qemu_opt.get('mem_size')
+
+        # Get huge pages information
+        huge_size = self._get_huge_page_size()
+        huge_free = self._get_huge_page_free(huge_size)
+        huge_total = self._get_huge_page_total(huge_size)
+
+        # Check if memory reqested by qemu is available on host
+        if (mem_size * 1024) > (huge_free * huge_size):
+            # If we want to allocate hugepage dynamically
+            if allocate:
+                mem_needed = abs((huge_free * huge_size) - (mem_size * 1024))
+                huge_to_allocate = ((mem_needed / huge_size) * 2) + huge_total
+                max_map_count = huge_to_allocate*4
+                # Increase maximum number of memory map areas a process may have
+                cmd = 'echo "{0}" | sudo tee /proc/sys/vm/max_map_count'.format(
+                    max_map_count)
+                (ret_code, _, stderr) = self._ssh.exec_command_sudo(cmd)
+                # Increase hugepage count
+                cmd = 'echo "{0}" | sudo tee /proc/sys/vm/nr_hugepages'.format(
+                    huge_to_allocate)
+                (ret_code, _, stderr) = self._ssh.exec_command_sudo(cmd)
+                if int(ret_code) != 0:
+                    logger.debug('Mount huge pages failed {0}'.format(stderr))
+                    raise RuntimeError('Mount huge pages failed on {0}'.format(
+                        self._node['host']))
+            # If we do not want to allocate dynamicaly end with error
+            else:
+                raise RuntimeError(
+                    'Not enough free huge pages: {0}, '
+                    '{1} MB'.format(huge_free, huge_free * huge_size)
+                )
+        # Check if huge pages mount point exist
+        has_huge_mnt = False
+        (_, output, _) = self._ssh.exec_command('cat /proc/mounts')
+        for line in output.splitlines():
+            # Try to find something like:
+            # none /mnt/huge hugetlbfs rw,relatime,pagesize=2048k 0 0
+            mount = line.split()
+            if mount[2] == 'hugetlbfs' and mount[1] == huge_mnt:
+                has_huge_mnt = True
+                break
+        # If huge page mount point not exist create one
+        if not has_huge_mnt:
+            cmd = 'mkdir -p {0}'.format(huge_mnt)
+            (ret_code, _, stderr) = self._ssh.exec_command_sudo(cmd)
+            if int(ret_code) != 0:
+                logger.debug('Create mount dir failed: {0}'.format(stderr))
+                raise RuntimeError('Create mount dir failed on {0}'.format(
+                    self._node['host']))
+            cmd = 'mount -t hugetlbfs -o pagesize=2048k none {0}'.format(
+                huge_mnt)
+            (ret_code, _, stderr) = self._ssh.exec_command_sudo(cmd)
+            if int(ret_code) != 0:
+                logger.debug('Mount huge pages failed {0}'.format(stderr))
+                raise RuntimeError('Mount huge pages failed on {0}'.format(
+                    self._node['host']))
+
+    def _get_huge_page_size(self):
+        """Get default size of huge pages in system.
+
+        :returns: Default size of free huge pages in system.
+        :rtype: int
+        :raises: RuntimeError if reading failed for three times.
+        """
+        # TODO: remove to dedicated library
+        cmd_huge_size = "grep Hugepagesize /proc/meminfo | awk '{ print $2 }'"
+        for _ in range(3):
+            (ret, out, _) = self._ssh.exec_command_sudo(cmd_huge_size)
+            if ret == 0:
+                try:
+                    huge_size = int(out)
+                except ValueError:
+                    logger.trace('Reading huge page size information failed')
+                else:
+                    break
+        else:
+            raise RuntimeError('Getting huge page size information failed.')
+        return huge_size
+
+    def _get_huge_page_free(self, huge_size):
+        """Get total number of huge pages in system.
+
+        :param huge_size: Size of hugepages.
+        :type huge_size: int
+        :returns: Number of free huge pages in system.
+        :rtype: int
+        :raises: RuntimeError if reading failed for three times.
+        """
+        # TODO: add numa aware option
+        # TODO: remove to dedicated library
+        cmd_huge_free = 'cat /sys/kernel/mm/hugepages/hugepages-{0}kB/'\
+            'free_hugepages'.format(huge_size)
+        for _ in range(3):
+            (ret, out, _) = self._ssh.exec_command_sudo(cmd_huge_free)
+            if ret == 0:
+                try:
+                    huge_free = int(out)
+                except ValueError:
+                    logger.trace('Reading free huge pages information failed')
+                else:
+                    break
+        else:
+            raise RuntimeError('Getting free huge pages information failed.')
+        return huge_free
+
+    def _get_huge_page_total(self, huge_size):
+        """Get total number of huge pages in system.
+
+        :param huge_size: Size of hugepages.
+        :type huge_size: int
+        :returns: Total number of huge pages in system.
+        :rtype: int
+        :raises: RuntimeError if reading failed for three times.
+        """
+        # TODO: add numa aware option
+        # TODO: remove to dedicated library
+        cmd_huge_total = 'cat /sys/kernel/mm/hugepages/hugepages-{0}kB/'\
+            'nr_hugepages'.format(huge_size)
+        for _ in range(3):
+            (ret, out, _) = self._ssh.exec_command_sudo(cmd_huge_total)
+            if ret == 0:
+                try:
+                    huge_total = int(out)
+                except ValueError:
+                    logger.trace('Reading total huge pages information failed')
+                else:
+                    break
+        else:
+            raise RuntimeError('Getting total huge pages information failed.')
+        return huge_total
+
+    def qemu_start(self):
+        """Start QEMU and wait until VM boot.
+
+        :return: VM node info.
+        :rtype: dict
+        .. note:: First set at least node to run QEMU on.
+        .. warning:: Starts only one VM on the node.
+        """
+        # SSH forwarding
+        ssh_fwd = '-net user,hostfwd=tcp::{0}-:22'.format(
+            self._qemu_opt.get('ssh_fwd_port'))
+        # Memory and huge pages
+        mem = '-object memory-backend-file,id=mem,size={0}M,mem-path={1},' \
+            'share=on -m {0} -numa node,memdev=mem'.format(
+                self._qemu_opt.get('mem_size'), self._qemu_opt.get('huge_mnt'))
+
+        # By default check only if hugepages are available.
+        # If 'huge_allocate' is set to true try to allocate as well.
+        self._huge_page_check(allocate=self._qemu_opt.get('huge_allocate'))
+
+        # Disk option
+        drive = '-drive file={0},format=raw,cache=none,if=virtio'.format(
+            self._qemu_opt.get('disk_image'))
+        # Setup QMP via unix socket
+        qmp = '-qmp unix:{0},server,nowait'.format(self._qmp_sock)
+        # Setup serial console
+        serial = '-chardev socket,host=127.0.0.1,port={0},id=gnc0,server,' \
+            'nowait -device isa-serial,chardev=gnc0'.format(
+                self._qemu_opt.get('serial_port'))
+        # Setup QGA via chardev (unix socket) and isa-serial channel
+        qga = '-chardev socket,path={0},server,nowait,id=qga0 ' \
+            '-device isa-serial,chardev=qga0'.format(self._qga_sock)
+        # Graphic setup
+        graphic = '-monitor none -display none -vga none'
+        # PID file
+        pid = '-pidfile {}'.format(self._pid_file)
+
+        # Run QEMU
+        cmd = '{0} {1} {2} {3} {4} {5} {6} {7} {8} {9} {10}'.format(
+            self._qemu_bin, self._qemu_opt.get('smp'), mem, ssh_fwd,
+            self._qemu_opt.get('options'),
+            drive, qmp, serial, qga, graphic, pid)
+        (ret_code, _, stderr) = self._ssh.exec_command_sudo(cmd, timeout=300)
+        if int(ret_code) != 0:
+            logger.debug('QEMU start failed {0}'.format(stderr))
+            raise RuntimeError('QEMU start failed on {0}'.format(
+                self._node['host']))
+        logger.trace('QEMU running')
+        # Wait until VM boot
+        try:
+            self._wait_until_vm_boot()
+        except (RuntimeError, SSHTimeout):
+            self.qemu_kill_all()
+            self.qemu_clear_socks()
+            raise
+        # 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 {0}, error: {1}'.format(
+                self._node['host'], 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 {0}, '
+                'error: {1}'.format(self._node['host'], 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 {0}, '
+                'error: {1}'.format(self._node['host'], 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 {}'.format(self._pid_file))
+        self._ssh.exec_command_sudo('kill -SIGKILL $(cat {})'
+                                    .format(self._pid_file))
+        # Delete PID file
+        cmd = 'rm -f {}'.format(self._pid_file)
+        self._ssh.exec_command_sudo(cmd)
+
+    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
+        cmd = 'fuser -k {}/tcp'.format(self._qemu_opt.get('serial_port'))
+        self._ssh.exec_command_sudo(cmd)
+        # Delete all created sockets
+        for sock in self._socks:
+            cmd = 'rm -f {}'.format(sock)
+            self._ssh.exec_command_sudo(cmd)
+
+    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
+
+        :return: 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 {0}, '
+                'error: {1}'.format(self._node['host'], json.dumps(err)))
+
     @staticmethod
-    def build_qemu(node):
+    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={0}'.format(Constants.QEMU_INSTALL_DIR)
+        version = ' --version={0}'.format(Constants.QEMU_INSTALL_VERSION)
+        force = ' --force' if force_install else ''
+        patch = ' --patch' if apply_patch else ''
+
         (ret_code, stdout, stderr) = \
-            ssh.exec_command('sudo -Sn bash {0}/{1}/qemu_build.sh'.format(
-                Constants.REMOTE_FW_DIR, Constants.RESOURCES_LIB_SH), 1000)
-        logger.trace(stdout)
-        if 0 != int(ret_code):
-            logger.debug('QEMU build failed {0}'.format(stderr))
+            ssh.exec_command(
+                "sudo -E sh -c '{0}/{1}/qemu_build.sh{2}{3}{4}{5}'"\
+                .format(Constants.REMOTE_FW_DIR, Constants.RESOURCES_LIB_SH,
+                        version, directory, force, patch), 1000)
+
+        if int(ret_code) != 0:
+            logger.debug('QEMU build failed {0}'.format(stdout + stderr))
             raise RuntimeError('QEMU build failed on {0}'.format(node['host']))