scripts: refactor the VM class in iotests for reuse

The iotests module has a python class for controlling QEMU
processes. Pull the generic functionality out of this file
and create a scripts/qemu.py module containing a QEMUMachine
class. Put the QTest integration support into a subclass
QEMUQtestMachine.

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Message-Id: <1469020993-29426-4-git-send-email-berrange@redhat.com>
Signed-off-by: Amit Shah <amit.shah@redhat.com>

3 files changed, 240 insertions, 131 deletions

diff --git a/scripts/qemu.py b/scripts/qemu.py
new file mode 100644
index 0000000000..9cdad24949
--- /dev/null
+++ b/scripts/qemu.py
@@ -0,0 +1,202 @@
+# QEMU library
+#
+# Copyright (C) 2015-2016 Red Hat Inc.
+# Copyright (C) 2012 IBM Corp.
+#
+# Authors:
+#  Fam Zheng <famz@redhat.com>
+#
+# This work is licensed under the terms of the GNU GPL, version 2.  See
+# the COPYING file in the top-level directory.
+#
+# Based on qmp.py.
+#
+
+import errno
+import string
+import os
+import sys
+import subprocess
+import qmp.qmp
+
+
+class QEMUMachine(object):
+    '''A QEMU VM'''
+
+    def __init__(self, binary, args=[], wrapper=[], name=None, test_dir="/var/tmp",
+                 monitor_address=None, debug=False):
+        if name is None:
+            name = "qemu-%d" % os.getpid()
+        if monitor_address is None:
+            monitor_address = os.path.join(test_dir, name + "-monitor.sock")
+        self._monitor_address = monitor_address
+        self._qemu_log_path = os.path.join(test_dir, name + ".log")
+        self._popen = None
+        self._binary = binary
+        self._args = args
+        self._wrapper = wrapper
+        self._events = []
+        self._iolog = None
+        self._debug = debug
+
+    # This can be used to add an unused monitor instance.
+    def add_monitor_telnet(self, ip, port):
+        args = 'tcp:%s:%d,server,nowait,telnet' % (ip, port)
+        self._args.append('-monitor')
+        self._args.append(args)
+
+    def add_fd(self, fd, fdset, opaque, opts=''):
+        '''Pass a file descriptor to the VM'''
+        options = ['fd=%d' % fd,
+                   'set=%d' % fdset,
+                   'opaque=%s' % opaque]
+        if opts:
+            options.append(opts)
+
+        self._args.append('-add-fd')
+        self._args.append(','.join(options))
+        return self
+
+    def send_fd_scm(self, fd_file_path):
+        # In iotest.py, the qmp should always use unix socket.
+        assert self._qmp.is_scm_available()
+        bin = socket_scm_helper
+        if os.path.exists(bin) == False:
+            print "Scm help program does not present, path '%s'." % bin
+            return -1
+        fd_param = ["%s" % bin,
+                    "%d" % self._qmp.get_sock_fd(),
+                    "%s" % fd_file_path]
+        devnull = open('/dev/null', 'rb')
+        p = subprocess.Popen(fd_param, stdin=devnull, stdout=sys.stdout,
+                             stderr=sys.stderr)
+        return p.wait()
+
+    @staticmethod
+    def _remove_if_exists(path):
+        '''Remove file object at path if it exists'''
+        try:
+            os.remove(path)
+        except OSError as exception:
+            if exception.errno == errno.ENOENT:
+                return
+            raise
+
+    def get_pid(self):
+        if not self._popen:
+            return None
+        return self._popen.pid
+
+    def _load_io_log(self):
+        with open(self._qemu_log_path, "r") as fh:
+            self._iolog = fh.read()
+
+    def _base_args(self):
+        if isinstance(self._monitor_address, tuple):
+            moncdev = "socket,id=mon,host=%s,port=%s" % (
+                self._monitor_address[0],
+                self._monitor_address[1])
+        else:
+            moncdev = 'socket,id=mon,path=%s' % self._monitor_address
+        return ['-chardev', moncdev,
+                '-mon', 'chardev=mon,mode=control',
+                '-display', 'none', '-vga', 'none']
+
+    def _pre_launch(self):
+        self._qmp = qmp.qmp.QEMUMonitorProtocol(self._monitor_address, server=True,
+                                                debug=self._debug)
+
+    def _post_launch(self):
+        self._qmp.accept()
+
+    def _post_shutdown(self):
+        if not isinstance(self._monitor_address, tuple):
+            self._remove_if_exists(self._monitor_address)
+        self._remove_if_exists(self._qemu_log_path)
+
+    def launch(self):
+        '''Launch the VM and establish a QMP connection'''
+        devnull = open('/dev/null', 'rb')
+        qemulog = open(self._qemu_log_path, 'wb')
+        try:
+            self._pre_launch()
+            args = self._wrapper + [self._binary] + self._base_args() + self._args
+            self._popen = subprocess.Popen(args, stdin=devnull, stdout=qemulog,
+                                           stderr=subprocess.STDOUT, shell=False)
+            self._post_launch()
+        except:
+            if self._popen:
+                self._popen.kill()
+            self._load_io_log()
+            self._post_shutdown()
+            self._popen = None
+            raise
+
+    def shutdown(self):
+        '''Terminate the VM and clean up'''
+        if not self._popen is None:
+            try:
+                self._qmp.cmd('quit')
+                self._qmp.close()
+            except:
+                self._popen.kill()
+
+            exitcode = self._popen.wait()
+            if exitcode < 0:
+                sys.stderr.write('qemu received signal %i: %s\n' % (-exitcode, ' '.join(self._args)))
+            self._load_io_log()
+            self._post_shutdown()
+            self._popen = None
+
+    underscore_to_dash = string.maketrans('_', '-')
+    def qmp(self, cmd, conv_keys=True, **args):
+        '''Invoke a QMP command and return the result dict'''
+        qmp_args = dict()
+        for k in args.keys():
+            if conv_keys:
+                qmp_args[k.translate(self.underscore_to_dash)] = args[k]
+            else:
+                qmp_args[k] = args[k]
+
+        return self._qmp.cmd(cmd, args=qmp_args)
+
+    def command(self, cmd, conv_keys=True, **args):
+        reply = self.qmp(cmd, conv_keys, **args)
+        if reply is None:
+            raise Exception("Monitor is closed")
+        if "error" in reply:
+            raise Exception(reply["error"]["desc"])
+        return reply["return"]
+
+    def get_qmp_event(self, wait=False):
+        '''Poll for one queued QMP events and return it'''
+        if len(self._events) > 0:
+            return self._events.pop(0)
+        return self._qmp.pull_event(wait=wait)
+
+    def get_qmp_events(self, wait=False):
+        '''Poll for queued QMP events and return a list of dicts'''
+        events = self._qmp.get_events(wait=wait)
+        events.extend(self._events)
+        del self._events[:]
+        self._qmp.clear_events()
+        return events
+
+    def event_wait(self, name, timeout=60.0, match=None):
+        # Search cached events
+        for event in self._events:
+            if (event['event'] == name) and event_match(event, match):
+                self._events.remove(event)
+                return event
+
+        # Poll for new events
+        while True:
+            event = self._qmp.pull_event(wait=timeout)
+            if (event['event'] == name) and event_match(event, match):
+                return event
+            self._events.append(event)
+
+        return None
+
+    def get_log(self):
+        return self._iolog
diff --git a/scripts/qtest.py b/scripts/qtest.py
index a9714453a2..03bc7f6c9b 100644
--- a/scripts/qtest.py
+++ b/scripts/qtest.py
@@ -13,6 +13,11 @@
 
 import errno
 import socket
+import string
+import os
+import subprocess
+import qmp.qmp
+import qemu
 
 class QEMUQtestProtocol(object):
     def __init__(self, address, server=False):
@@ -69,3 +74,32 @@ class QEMUQtestProtocol(object):
 
     def settimeout(self, timeout):
         self._sock.settimeout(timeout)
+
+
+class QEMUQtestMachine(qemu.QEMUMachine):
+    '''A QEMU VM'''
+
+    def __init__(self, binary, args=[], name=None, test_dir="/var/tmp"):
+        super(self, QEMUQtestMachine).__init__(binary, args, name, test_dir)
+        self._qtest_path = os.path.join(test_dir, name + "-qtest.sock")
+
+    def _base_args(self):
+        args = super(self, QEMUQtestMachine)._base_args()
+        args.extend(['-qtest', 'unix:path=' + self._qtest_path])
+        return args
+
+    def _pre_launch(self):
+        super(self, QEMUQtestMachine)._pre_launch()
+        self._qtest = QEMUQtestProtocol(self._qtest_path, server=True)
+
+    def _post_launch(self):
+        super(self, QEMUQtestMachine)._post_launch()
+        self._qtest.accept()
+
+    def _post_shutdown(self):
+        super(self, QEMUQtestMachine)._post_shutdown()
+        self._remove_if_exists(self._qtest_path)
+
+    def qtest(self, cmd):
+        '''Send a qtest command to guest'''
+        return self._qtest.cmd(cmd)
diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 1687c33efd..14427f44f9 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -24,8 +24,6 @@ import string
 import unittest
 import sys
 sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..', 'scripts'))
-sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..', 'scripts', 'qmp'))
-import qmp
 import qtest
 import struct
 import json
@@ -41,9 +39,8 @@ qemu_io_args = [os.environ.get('QEMU_IO_PROG', 'qemu-io')]
 if os.environ.get('QEMU_IO_OPTIONS'):
     qemu_io_args += os.environ['QEMU_IO_OPTIONS'].strip().split(' ')
 
-qemu_args = [os.environ.get('QEMU_PROG', 'qemu')]
-if os.environ.get('QEMU_OPTIONS'):
-    qemu_args += os.environ['QEMU_OPTIONS'].strip().split(' ')
+qemu_prog = [os.environ.get('QEMU_PROG', 'qemu')]
+qemu_opts = os.environ.get('QEMU_OPTIONS', '').strip().split(' ')
 
 imgfmt = os.environ.get('IMGFMT', 'raw')
 imgproto = os.environ.get('IMGPROTO', 'file')
@@ -148,27 +145,12 @@ def event_match(event, match=None):
 
     return True
 
-class VM(object):
+class VM(qtest.QEMUMachine):
     '''A QEMU VM'''
 
     def __init__(self):
-        self._monitor_path = os.path.join(test_dir, 'qemu-mon.%d' % os.getpid())
-        self._qemu_log_path = os.path.join(test_dir, 'qemu-log.%d' % os.getpid())
-        self._qtest_path = os.path.join(test_dir, 'qemu-qtest.%d' % os.getpid())
-        self._args = qemu_args + ['-chardev',
-                     'socket,id=mon,path=' + self._monitor_path,
-                     '-mon', 'chardev=mon,mode=control',
-                     '-qtest', 'unix:path=' + self._qtest_path,
-                     '-machine', 'accel=qtest',
-                     '-display', 'none', '-vga', 'none']
+        super(self, VM).__init__(qemu_prog, qemu_opts, test_dir)
         self._num_drives = 0
-        self._events = []
-
-    # This can be used to add an unused monitor instance.
-    def add_monitor_telnet(self, ip, port):
-        args = 'tcp:%s:%d,server,nowait,telnet' % (ip, port)
-        self._args.append('-monitor')
-        self._args.append(args)
 
     def add_drive_raw(self, opts):
         self._args.append('-drive')
@@ -211,106 +193,6 @@ class VM(object):
         return self.qmp('human-monitor-command',
                         command_line='qemu-io %s "%s"' % (drive, cmd))
 
-    def add_fd(self, fd, fdset, opaque, opts=''):
-        '''Pass a file descriptor to the VM'''
-        options = ['fd=%d' % fd,
-                   'set=%d' % fdset,
-                   'opaque=%s' % opaque]
-        if opts:
-            options.append(opts)
-
-        self._args.append('-add-fd')
-        self._args.append(','.join(options))
-        return self
-
-    def send_fd_scm(self, fd_file_path):
-        # In iotest.py, the qmp should always use unix socket.
-        assert self._qmp.is_scm_available()
-        bin = socket_scm_helper
-        if os.path.exists(bin) == False:
-            print "Scm help program does not present, path '%s'." % bin
-            return -1
-        fd_param = ["%s" % bin,
-                    "%d" % self._qmp.get_sock_fd(),
-                    "%s" % fd_file_path]
-        devnull = open('/dev/null', 'rb')
-        p = subprocess.Popen(fd_param, stdin=devnull, stdout=sys.stdout,
-                             stderr=sys.stderr)
-        return p.wait()
-
-    def launch(self):
-        '''Launch the VM and establish a QMP connection'''
-        devnull = open('/dev/null', 'rb')
-        qemulog = open(self._qemu_log_path, 'wb')
-        try:
-            self._qmp = qmp.QEMUMonitorProtocol(self._monitor_path, server=True)
-            self._qtest = qtest.QEMUQtestProtocol(self._qtest_path, server=True)
-            self._popen = subprocess.Popen(self._args, stdin=devnull, stdout=qemulog,
-                                           stderr=subprocess.STDOUT)
-            self._qmp.accept()
-            self._qtest.accept()
-        except:
-            _remove_if_exists(self._monitor_path)
-            _remove_if_exists(self._qtest_path)
-            raise
-
-    def shutdown(self):
-        '''Terminate the VM and clean up'''
-        if not self._popen is None:
-            self._qmp.cmd('quit')
-            exitcode = self._popen.wait()
-            if exitcode < 0:
-                sys.stderr.write('qemu received signal %i: %s\n' % (-exitcode, ' '.join(self._args)))
-            os.remove(self._monitor_path)
-            os.remove(self._qtest_path)
-            os.remove(self._qemu_log_path)
-            self._popen = None
-
-    underscore_to_dash = string.maketrans('_', '-')
-    def qmp(self, cmd, conv_keys=True, **args):
-        '''Invoke a QMP command and return the result dict'''
-        qmp_args = dict()
-        for k in args.keys():
-            if conv_keys:
-                qmp_args[k.translate(self.underscore_to_dash)] = args[k]
-            else:
-                qmp_args[k] = args[k]
-
-        return self._qmp.cmd(cmd, args=qmp_args)
-
-    def qtest(self, cmd):
-        '''Send a qtest command to guest'''
-        return self._qtest.cmd(cmd)
-
-    def get_qmp_event(self, wait=False):
-        '''Poll for one queued QMP events and return it'''
-        if len(self._events) > 0:
-            return self._events.pop(0)
-        return self._qmp.pull_event(wait=wait)
-
-    def get_qmp_events(self, wait=False):
-        '''Poll for queued QMP events and return a list of dicts'''
-        events = self._qmp.get_events(wait=wait)
-        events.extend(self._events)
-        del self._events[:]
-        self._qmp.clear_events()
-        return events
-
-    def event_wait(self, name='BLOCK_JOB_COMPLETED', timeout=60.0, match=None):
-        # Search cached events
-        for event in self._events:
-            if (event['event'] == name) and event_match(event, match):
-                self._events.remove(event)
-                return event
-
-        # Poll for new events
-        while True:
-            event = self._qmp.pull_event(wait=timeout)
-            if (event['event'] == name) and event_match(event, match):
-                return event
-            self._events.append(event)
-
-        return None
 
 index_re = re.compile(r'([^\[]+)\[([^\]]+)\]')
 
@@ -427,15 +309,6 @@ class QMPTestCase(unittest.TestCase):
         event = self.wait_until_completed(drive=drive)
         self.assert_qmp(event, 'data/type', 'mirror')
 
-def _remove_if_exists(path):
-    '''Remove file object at path if it exists'''
-    try:
-        os.remove(path)
-    except OSError as exception:
-        if exception.errno == errno.ENOENT:
-           return
-        raise
-
 def notrun(reason):
     '''Skip this test suite'''
     # Each test in qemu-iotests has a number ("seq")