CSIT-1386 KernelVM - Part I

- Refactor QemuUtils

Full refactor of QemuUtils to prepare for thinner VMs.

Change-Id: I171ba11a9e6e9faec582bd58df6819598b0ed0b5
Signed-off-by: Peter Mikus <pmikus@cisco.com>

1 files changed, 330 insertions, 435 deletions

diff --git a/resources/libraries/python/QemuUtils.py b/resources/libraries/python/QemuUtils.py
index 6fad6ed8b7..74965ec580 100644
--- a/resources/libraries/python/QemuUtils.py
+++ b/resources/libraries/python/QemuUtils.py
@@ -15,157 +15,221 @@
 
 from time import time, sleep
 import json
-import re
+from re import match
 # 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.ssh import exec_cmd, exec_cmd_no_error
 from resources.libraries.python.Constants import Constants
 from resources.libraries.python.DUTSetup import DUTSetup
 from resources.libraries.python.topology import NodeType, Topology
 
+__all__ = ["QemuOptions", "QemuUtils"]
 
-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')]
+class QemuOptions(object):
+    """QEMU option class.
 
-    def qemu_set_path(self, path):
-        """Set binary path for QEMU.
+    The class can handle input parameters or parameters that acts as QEMU
+    command line parameters. The only variable is a list of dictionaries
+    where dictionaries can be added multiple times. This emulates the QEMU
+    behavior where one command line parameter can be used multiple times (1..N).
+    Example can be device or object (so it is not an issue to have one memory
+    block of 2G and and second memory block of 512M but from other numa).
 
-        :param path: Absolute path in filesystem.
-        :type path: str
-        """
-        self._qemu_opt['qemu_path'] = path
+    Class does support get value or string representation that will return
+    space separated, dash prefixed string of key value pairs used for command
+    line.
+    """
 
-    def qemu_set_queue_count(self, count):
-        """Set number of virtio queues.
+    # Use one instance of class per tests.
+    ROBOT_LIBRARY_SCOPE = 'TEST CASE'
 
-        :param count: Number of virtio queues.
-        :type count: int
-        """
-        self._qemu_opt['queue_count'] = int(count)
+    def __init__(self):
+        self.variables = list()
 
-    def qemu_set_queue_size(self, size):
-        """Set RX/TX size of virtio queues.
+    def add(self, variable, value):
+        """Add parameter to the list.
 
-        :param size: Size of virtio queues.
-        :type size: int
+        :param variable: QEMU parameter.
+        :param value: Parameter value.
+        :type variable: str
+        :type value: str or int
         """
-        self._qemu_opt['queue_size'] = int(size)
+        self.variables.append({str(variable): value})
 
-    def qemu_set_smp(self, smp, cores, threads, sockets):
-        """Set SMP option for QEMU.
+    def get(self, variable):
+        """Get parameter of variable(s) from list that matches input value.
 
-        :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
+        :param variable: QEMU parameter to get.
+        :type variable: str
+        :returns: List of values or value that matches input parameter.
+        :rtype: list or str
         """
-        self._qemu_opt['smp'] = \
-            ('-smp {smp},cores={cores},threads={threads},sockets={sockets}'.
-             format(smp=smp, cores=cores, threads=threads, sockets=sockets))
+        selected = [d[variable] for d in self.variables if variable in d]
+        return selected if len(selected) > 1 else selected[0]
 
-    def qemu_set_ssh_fwd_port(self, fwd_port):
-        """Set host port for guest SSH forwarding.
+    def get_values(self):
+        """Get all values from dict items in list.
 
-        :param fwd_port: Port number on host for guest SSH forwarding.
-        :type fwd_port: int
+        :returns: List of all dictionary values.
+        :rtype: list
         """
-        self._qemu_opt['ssh_fwd_port'] = fwd_port
-        self._vm_info['port'] = fwd_port
+        return [d.values()[0] for d in self.variables]
 
-    def qemu_set_serial_port(self, port):
-        """Set serial console port.
+    def __str__(self):
+        """Return space separated string of key value pairs.
 
-        :param port: Serial console port.
-        :type port: int
+        :returns: Space separated string of key value pairs.
+        :rtype: str
         """
-        self._qemu_opt['serial_port'] = port
+        return " ".join(["-{k} {v}".format(k=d.keys()[0], v=d.values()[0])
+                         for d in self.variables])
 
-    def qemu_set_mem_size(self, mem_size):
-        """Set virtual RAM size.
+class QemuUtils(object):
+    """QEMU utilities."""
 
-        :param mem_size: RAM size in Mega Bytes.
-        :type mem_size: int
-        """
-        self._qemu_opt['mem_size'] = int(mem_size)
+    # Use one instance of class per tests.
+    ROBOT_LIBRARY_SCOPE = 'TEST CASE'
 
-    def qemu_set_huge_mnt(self, huge_mnt):
-        """Set hugefile mount point.
+    def __init__(self, node=None, qemu_id=1, smp=1, mem=512, vnf=None,
+                 img='/var/lib/vm/vhost-nested.img', bin_path='/usr/bin'):
+        """Initialize QemuUtil class.
 
-        :param huge_mnt: System hugefile mount point.
-        :type huge_mnt: int
+        :param node: Node to run QEMU on.
+        :param qemu_id: QEMU identifier.
+        :param smp: Number of virtual SMP units (cores).
+        :param mem: Amount of memory.
+        :param vnf: Network function workload.
+        :param img: QEMU disk image or kernel image path.
+        :param bin_path: QEMU binary path.
+        :type node: dict
+        :type qemu_id: int
+        :type smp: int
+        :type mem: int
+        :type vnf: str
+        :type img: str
+        :type bin_path: str
         """
-        self._qemu_opt['huge_mnt'] = huge_mnt
+        self._vhost_id = 0
+        self._vm_info = {
+            'type': NodeType.VM,
+            'port': 10021 + qemu_id,
+            'serial': 4555 + qemu_id,
+            'username': 'cisco',
+            'password': 'cisco',
+            'interfaces': {},
+        }
+        if node:
+            self.qemu_set_node(node)
+        # Input Options.
+        self._opt = QemuOptions()
+        self._opt.add('qemu_id', qemu_id)
+        self._opt.add('bin_path', bin_path)
+        self._opt.add('mem', int(mem))
+        self._opt.add('smp', int(smp))
+        self._opt.add('img', img)
+        self._opt.add('vnf', vnf)
+        # Temporary files.
+        self._temp = QemuOptions()
+        self._temp.add('pid', '/var/run/qemu_{id}.pid'.format(id=qemu_id))
+        # Computed parameters for QEMU command line.
+        if '/var/lib/vm/' in img:
+            self._opt.add('vm_type', 'nestedvm')
+            self._temp.add('qmp', '/var/run/qmp_{id}.sock'.format(id=qemu_id))
+            self._temp.add('qga', '/var/run/qga_{id}.sock'.format(id=qemu_id))
+        else:
+            raise RuntimeError('QEMU: Unknown VM image option!')
+        self._params = QemuOptions()
+        self.add_params()
+
+    def add_params(self):
+        """Set QEMU command line parameters."""
+        self.add_default_params()
+        if self._opt.get('vm_type') == 'nestedvm':
+            self.add_nestedvm_params()
+        else:
+            raise RuntimeError('QEMU: Unsupported VM type!')
+
+    def add_default_params(self):
+        """Set default QEMU command line parameters."""
+        self._params.add('daemonize', '')
+        self._params.add('nodefaults', '')
+        self._params.add('name', 'vnf{qemu},debug-threads=on'.
+                         format(qemu=self._opt.get('qemu_id')))
+        self._params.add('no-user-config', '')
+        self._params.add('monitor', 'none')
+        self._params.add('display', 'none')
+        self._params.add('vga', 'none')
+        self._params.add('enable-kvm', '')
+        self._params.add('pidfile', '{pid}'.
+                         format(pid=self._temp.get('pid')))
+        self._params.add('cpu', 'host')
+        self._params.add('machine', 'pc,accel=kvm,usb=off,mem-merge=off')
+        self._params.add('smp', '{smp},sockets=1,cores={smp},threads=1'.
+                         format(smp=self._opt.get('smp')))
+        self._params.add('object',
+                         'memory-backend-file,id=mem,size={mem}M,'
+                         'mem-path=/mnt/huge,share=on'.
+                         format(mem=self._opt.get('mem')))
+        self._params.add('m', '{mem}M'.
+                         format(mem=self._opt.get('mem')))
+        self._params.add('numa', 'node,memdev=mem')
+        self._params.add('balloon', 'none')
+
+    def add_nestedvm_params(self):
+        """Set NestedVM QEMU parameters."""
+        self._params.add('net', 'nic,macaddr=52:54:00:00:{qemu:02x}:ff'.
+                         format(qemu=self._opt.get('qemu_id')))
+        self._params.add('net', 'user,hostfwd=tcp::{info[port]}-:22'.
+                         format(info=self._vm_info))
+        # TODO: Remove try except after fully migrated to Bionic or
+        # qemu_set_node is removed.
+        try:
+            locking = ',file.locking=off'\
+                if self.qemu_version(version='2.10') else ''
+        except AttributeError:
+            locking = ''
+        self._params.add('drive',
+                         'file={img},format=raw,cache=none,if=virtio{locking}'.
+                         format(img=self._opt.get('img'), locking=locking))
+        self._params.add('qmp', 'unix:{qmp},server,nowait'.
+                         format(qmp=self._temp.get('qmp')))
+        self._params.add('chardev', 'socket,host=127.0.0.1,port={info[serial]},'
+                         'id=gnc0,server,nowait'.format(info=self._vm_info))
+        self._params.add('device', 'isa-serial,chardev=gnc0')
+        self._params.add('chardev',
+                         'socket,path={qga},server,nowait,id=qga0'.
+                         format(qga=self._temp.get('qga')))
+        self._params.add('device', 'isa-serial,chardev=qga0')
+
+    def qemu_set_node(self, node):
+        """Set node to run QEMU on.
 
-    def qemu_set_huge_allocate(self):
-        """Set flag to allocate more huge pages if needed."""
-        self._qemu_opt['huge_allocate'] = True
+        :param node: Node to run QEMU on.
+        :type node: dict
+        """
+        self._node = node
+        self._vm_info['host'] = node['host']
+        if node['port'] != 22:
+            self._vm_info['host_port'] = node['port']
+            self._vm_info['host_username'] = node['username']
+            self._vm_info['host_password'] = node['password']
 
-    def qemu_set_disk_image(self, disk_image):
-        """Set disk image.
+    def get_qemu_pids(self):
+        """Get QEMU CPU pids.
 
-        :param disk_image: Path of the disk image.
-        :type disk_image: str
+        :returns: List of QEMU CPU pids.
+        :rtype: list of str
         """
-        self._qemu_opt['disk_image'] = disk_image
+        command = ("grep -rwl 'CPU' /proc/$(sudo cat {pid})/task/*/comm ".
+                   format(pid=self._temp.get('pid')))
+        command += (r"| xargs dirname | sed -e 's/\/.*\///g'")
+
+        stdout, _ = exec_cmd_no_error(self._node, command)
+        return stdout.splitlines()
 
     def qemu_set_affinity(self, *host_cpus):
         """Set qemu affinity by getting thread PIDs via QMP and taskset to list
@@ -174,18 +238,22 @@ class QemuUtils(object):
         :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']))
+        try:
+            qemu_cpus = self.get_qemu_pids()
+
+            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):
+                command = ('taskset -pc {host_cpu} {thread}'.
+                           format(host_cpu=host_cpu, thread=qemu_cpu))
+                message = ('QEMU: Set affinity failed on {host}!'.
+                           format(host=self._node['host']))
+                exec_cmd_no_error(self._node, command, sudo=True,
+                                  message=message)
+        except (RuntimeError, ValueError):
+            self.qemu_kill_all()
+            raise
 
     def qemu_set_scheduler_policy(self):
         """Set scheduler policy to SCHED_RR with priority 1 for all Qemu CPU
@@ -193,88 +261,65 @@ class QemuUtils(object):
 
         :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']
-        if node['port'] != 22:
-            self._vm_info['host_port'] = node['port']
-            self._vm_info['host_username'] = node['username']
-            self._vm_info['host_password'] = node['password']
-        arch = Topology.get_node_arch(node)
-        self._qemu_opt['qemu_bin'] = 'qemu-system-{arch}'.format(arch=arch)
+        try:
+            qemu_cpus = self.get_qemu_pids()
+
+            for qemu_cpu in qemu_cpus:
+                command = ('chrt -r -p 1 {thread}'.
+                           format(thread=qemu_cpu))
+                message = ('QEMU: Set SCHED_RR failed on {host}'.
+                           format(host=self._node['host']))
+                exec_cmd_no_error(self._node, command, sudo=True,
+                                  message=message)
+        except (RuntimeError, ValueError):
+            self.qemu_kill_all()
+            raise
 
-    def qemu_add_vhost_user_if(self, socket, server=True, mac=None,
-                               jumbo_frames=False):
+    def qemu_add_vhost_user_if(self, socket, server=True, jumbo_frames=False,
+                               queue_size=None, queues=1):
         """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.
+        :param queue_size: Vring queue size.
+        :param queues: Number of queues.
         :type socket: str
         :type server: bool
-        :type mac: str
         :type jumbo_frames: bool
+        :type queue_size: int
+        :type queues: int
         """
         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
-
+        self._params.add('chardev',
+                         'socket,id=char{vhost},path={socket}{server}'.
+                         format(vhost=self._vhost_id, socket=socket,
+                                server=',server' if server is True else ''))
+        self._params.add('netdev',
+                         'vhost-user,id=vhost{vhost},'
+                         'chardev=char{vhost},queues={queues}'.
+                         format(vhost=self._vhost_id, queues=queues))
+        mac = ('52:54:00:00:{qemu:02x}:{vhost:02x}'.
+               format(qemu=self._opt.get('qemu_id'), vhost=self._vhost_id))
         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 ''
-        vector_size = ('vectors={vectors}'.
-                       format(vectors=2*self._qemu_opt.get('queue_count')+2))\
-            if self._qemu_opt.get('queue_count') else ''
-
-        # Create Virtio network device.
-        device = (' -device virtio-net-pci,netdev=vhost{vhost_id},mac={mac},'
-                  'mq=on,{vector_size},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,host_mtu=9200' if jumbo_frames else 'off',
-                         queue_size=queue_size, vector_size=vector_size))
-        self._qemu_opt['options'] += device
-        # Add interface MAC and socket to the node dict
+                      format(queue_size=queue_size)) if queue_size else ''
+        mbuf = 'on,host_mtu=9200'
+        self._params.add('device',
+                         'virtio-net-pci,netdev=vhost{vhost},'
+                         'mac={mac},mq=on,vectors={vectors},csum=off,gso=off,'
+                         'guest_tso4=off,guest_tso6=off,guest_ecn=off,'
+                         'mrg_rxbuf={mbuf},{queue_size}'.
+                         format(vhost=self._vhost_id, mac=mac,
+                                mbuf=mbuf if jumbo_frames else 'off',
+                                queue_size=queue_size,
+                                vectors=(2 * queues + 2)))
+
+        # 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)
+        if_name = 'vhost{vhost}'.format(vhost=self._vhost_id)
         self._vm_info['interfaces'][if_name] = if_data
-        # Add socket to the socket list
-        self._socks.append(socket)
+        # Add socket to temporary file list.
+        self._temp.add(if_name, socket)
 
     def _qemu_qmp_exec(self, cmd):
         """Execute QMP command.
@@ -288,14 +333,15 @@ class QemuUtils(object):
             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']))
+        command = ('echo "{{ \\"execute\\": \\"qmp_capabilities\\" }}'
+                   '{{ \\"execute\\": \\"{cmd}\\" }}" | '
+                   'sudo -S socat - UNIX-CONNECT:{qmp}'.
+                   format(cmd=cmd, qmp=self._temp.get('qmp')))
+        message = ('QMP execute "{cmd}" failed on {host}'.
+                   format(cmd=cmd, host=self._node['host']))
+        stdout, _ = exec_cmd_no_error(self._node, command, sudo=False,
+                                      message=message)
+
         # Skip capabilities negotiation messages.
         out_list = stdout.splitlines()
         if len(out_list) < 3:
@@ -305,16 +351,14 @@ class QemuUtils(object):
 
     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])
+        command = ('(printf "\xFF"; sleep 1) | '
+                   'sudo -S socat - UNIX-CONNECT:{qga}'.
+                   format(qga=self._temp.get('qga')))
+        message = ('QGA flush failed on {host}'.format(host=self._node['host']))
+        stdout, _ = exec_cmd_no_error(self._node, command, sudo=False,
+                                      message=message)
+
+        return json.loads(stdout.split('\n', 1)[0]) if stdout else dict()
 
     def _qemu_qga_exec(self, cmd):
         """Execute QGA command.
@@ -324,16 +368,15 @@ class QemuUtils(object):
         :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])
+        command = ('(echo "{{ \\"execute\\": \\"{cmd}\\" }}"; sleep 1) | '
+                   'sudo -S socat - UNIX-CONNECT:{qga}'.
+                   format(cmd=cmd, qga=self._temp.get('qga')))
+        message = ('QGA execute "{cmd}" failed on {host}'.
+                   format(cmd=cmd, host=self._node['host']))
+        stdout, _ = exec_cmd_no_error(self._node, command, sudo=False,
+                                      message=message)
+
+        return json.loads(stdout.split('\n', 1)[0]) if stdout else dict()
 
     def _wait_until_vm_boot(self, timeout=60):
         """Wait until QEMU VM is booted.
@@ -347,9 +390,8 @@ class QemuUtils(object):
         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']))
+                raise RuntimeError('timeout, VM not booted on {host}'.
+                                   format(host=self._node['host']))
             out = None
             try:
                 out = self._qemu_qga_flush()
@@ -363,23 +405,21 @@ class QemuUtils(object):
                 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']))
+                raise RuntimeError('timeout, VM not booted on {host}'.
+                                   format(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
+            # Empty output - VM not booted yet.
             if not out:
                 sleep(5)
-            # Non-error return - VM booted
+            # Non-error return - VM booted.
             elif out.get('return') is not None:
                 break
-            # Skip error and wait
+            # Skip error and wait.
             elif out.get('error') is not None:
                 sleep(5)
             else:
@@ -388,29 +428,25 @@ class QemuUtils(object):
                 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']))
+        logger.trace('VM booted on {host}'.format(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"}]}
+        # {"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
+            raise RuntimeError('Get VM interface list failed on {host}'.
+                               format(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
+        # 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)
@@ -423,119 +459,38 @@ class QemuUtils(object):
     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))
+        DUTSetup.check_huge_page(self._node, '/mnt/huge', self._opt.get('mem'))
+
+        command = ('{bin_path}/qemu-system-{arch} {params}'.
+                   format(bin_path=self._opt.get('bin_path'),
+                          arch=Topology.get_node_arch(self._node),
+                          params=self._params))
+        message = ('QEMU: Start failed on {host}!'.
+                   format(host=self._node['host']))
+
         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
+            exec_cmd_no_error(self._node, command, timeout=300, sudo=True,
+                              message=message)
             self._wait_until_vm_boot()
-        except (RuntimeError, SSHTimeout):
+            # Update interface names in VM node dict.
+            self._update_vm_interfaces()
+        except RuntimeError:
             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')))
+        exec_cmd(self._node, 'chmod +r {pid}'.
+                 format(pid=self._temp.get('pid')), sudo=True)
+        exec_cmd(self._node, 'kill -SIGKILL $(cat {pid})'.
+                 format(pid=self._temp.get('pid')), sudo=True)
+
+        for value in self._temp.get_values():
+            exec_cmd(self._node, 'rm -f {value}'.format(value=value), sudo=True)
 
     def qemu_kill_all(self, node=None):
         """Kill all qemu processes on DUT node if specified.
@@ -545,86 +500,31 @@ class QemuUtils(object):
         """
         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)))
+        exec_cmd(self._node, 'pkill -SIGKILL qemu', sudo=True)
 
-    def qemu_version(self):
-        """Return Qemu version.
+        for value in self._temp.get_values():
+            exec_cmd(self._node, 'rm -f {value}'.format(value=value), sudo=True)
 
-        :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')))
+    def qemu_version(self, version=None):
+        """Return Qemu version or compare if version is higher than parameter.
 
+        :param version: Version to compare.
+        :type version: str
+        :returns: Qemu version or Boolean if version is higher than parameter.
+        :rtype: str or bool
+        """
+        command = ('{bin_path}/qemu-system-{arch} --version'.
+                   format(bin_path=self._opt.get('bin_path'),
+                          arch=Topology.get_node_arch(self._node)))
         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):
+            stdout, _ = exec_cmd_no_error(self._node, command, sudo=True)
+            ver = match(r'QEMU emulator version ([\d.]*)', stdout).group(1)
+            return StrictVersion(ver) > StrictVersion(version) \
+                if version else ver
+        except RuntimeError:
             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.
@@ -637,9 +537,6 @@ class QemuUtils(object):
         :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'))
@@ -647,18 +544,16 @@ class QemuUtils(object):
                    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']))
+                       format(arch=Topology.get_node_arch(node)))
+
+        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))
+        message = ('QEMU: Build failed on {host}!'.format(host=node['host']))
+        exec_cmd_no_error(node, command, sudo=False, message=message,
+                          timeout=1000)