Re: [Qemu-devel] [PATCH v5 15/15] test: add image streaming test cases

[Stefan Hajnoczi]

Hi Lucas,
The Python script below verifies the image streaming feature.  It's
built on the standard library "unittest" module, as well as QEMU's
qmp.py module.  It spawns a qemu process and creates necessary disk
image files.  The tests themselves issue QMP commands and check their
result or wait for QMP events to be raised.

I think this sort of test could be done with kvm-autotest but I don't
see much usage of cmd_qmp() in client/tests/kvm/tests/.  I'm curious
how you would approach this.  The high-level steps are:

1. Create a backing file.
2. Create a test QED image file using the backing file.
3. Issue "block_stream device=drive0" to the running VM.  This should
return no value.
4. Wait for the BLOCK_JOB_COMPLETED QMP event and check its fields -
they must contain expected values.
5. Ensure "query-block-job" does not show any active jobs anymore.
6. Use qemu-io's map command to verify that the image stays compact
and isn't bloated with actual zero bytes (this is kind of unrelated to
the rest of the test).

The other test cases share much of the same building blocks as
TestSingleDrive, so they are less interesting.

Would it be possible to look at TestSingleDrive below and give a
kvm-autotest equivalent?

Thanks,
Stefan

On Fri, Jan 13, 2012 at 1:14 PM, Stefan Hajnoczi
<address@hidden> wrote:
> python test-stream.py
>
> Signed-off-by: Stefan Hajnoczi <address@hidden>
> ---
>  test-stream.py |  208 
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
>  1 files changed, 208 insertions(+), 0 deletions(-)
>  create mode 100644 test-stream.py
>
> diff --git a/test-stream.py b/test-stream.py
> new file mode 100644
> index 0000000..16cbe5d
> --- /dev/null
> +++ b/test-stream.py
> @@ -0,0 +1,208 @@
> +#!/usr/bin/env python
> +import unittest
> +import subprocess
> +import re
> +import os
> +import sys; sys.path.append('QMP/')
> +import qmp
> +
> +def qemu_img(*args):
> +    devnull = open('/dev/null', 'r+')
> +    return subprocess.call(['./qemu-img'] + list(args), stdin=devnull, 
> stdout=devnull)
> +
> +def qemu_io(*args):
> +    args = ['./qemu-io'] + list(args)
> +    return subprocess.Popen(args, stdout=subprocess.PIPE).communicate()[0]
> +
> +class VM(object):
> +    def __init__(self):
> +        self._monitor_path = '/tmp/qemu-mon.%d' % os.getpid()
> +        self._qemu_log_path = '/tmp/qemu-log.%d' % os.getpid()
> +        self._args = ['x86_64-softmmu/qemu-system-x86_64',
> +                      '-chardev', 'socket,id=mon,path=' + self._monitor_path,
> +                      '-mon', 'chardev=mon,mode=control', '-nographic']
> +        self._num_drives = 0
> +
> +    def add_drive(self, path, opts=''):
> +        options = ['if=virtio',
> +                   'cache=none',
> +                   'file=%s' % path,
> +                   'id=drive%d' % self._num_drives]
> +        if opts:
> +            options.append(opts)
> +
> +        self._args.append('-drive')
> +        self._args.append(','.join(options))
> +        self._num_drives += 1
> +        return self
> +
> +    def launch(self):
> +        devnull = open('/dev/null', 'rb')
> +        qemulog = open(self._qemu_log_path, 'wb')
> +        self._qmp = qmp.QEMUMonitorProtocol(self._monitor_path, server=True)
> +        self._popen = subprocess.Popen(self._args, stdin=devnull, 
> stdout=qemulog,
> +                                       stderr=subprocess.STDOUT)
> +        self._qmp.accept()
> +
> +    def shutdown(self):
> +        self._qmp.cmd('quit')
> +        self._popen.wait()
> +        os.remove(self._monitor_path)
> +        os.remove(self._qemu_log_path)
> +
> +    def qmp(self, cmd, **args):
> +        return self._qmp.cmd(cmd, args=args)
> +
> +    def get_qmp_events(self, wait=False):
> +        events = self._qmp.get_events(wait=wait)
> +        self._qmp.clear_events()
> +        return events
> +
> +index_re = re.compile(r'([^\[]+)\[([^\]]+)\]')
> +
> +class QMPTestCase(unittest.TestCase):
> +    def dictpath(self, d, path):
> +        """Traverse a path in a nested dict"""
> +        for component in path.split('/'):
> +            m = index_re.match(component)
> +            if m:
> +                component, idx = m.groups()
> +                idx = int(idx)
> +
> +            if not isinstance(d, dict) or component not in d:
> +                self.fail('failed path traversal for "%s" in "%s"' % (path, 
> str(d)))
> +            d = d[component]
> +
> +            if m:
> +                if not isinstance(d, list):
> +                    self.fail('path component "%s" in "%s" is not a list in 
> "%s"' % (component, path, str(d)))
> +                try:
> +                    d = d[idx]
> +                except IndexError:
> +                    self.fail('invalid index "%s" in path "%s" in "%s"' % 
> (idx, path, str(d)))
> +        return d
> +
> +    def assert_qmp(self, d, path, value):
> +        result = self.dictpath(d, path)
> +        self.assertEqual(result, value, 'values not equal "%s" and "%s"' % 
> (str(result), str(value)))
> +
> +    def assert_no_active_streams(self):
> +        result = self.vm.qmp('query-block-jobs')
> +        self.assert_qmp(result, 'return', [])
> +
> +class TestSingleDrive(QMPTestCase):
> +    image_len = 1 * 1024 * 1024 # MB
> +
> +    def setUp(self):
> +        qemu_img('create', 'backing.img', str(TestSingleDrive.image_len))
> +        qemu_img('create', '-f', 'qed', '-o', 'backing_file=backing.img', 
> 'test.qed')
> +        self.vm = VM().add_drive('test.qed')
> +        self.vm.launch()
> +
> +    def tearDown(self):
> +        self.vm.shutdown()
> +        os.remove('test.qed')
> +        os.remove('backing.img')
> +
> +    def test_stream(self):
> +        self.assert_no_active_streams()
> +
> +        result = self.vm.qmp('block_stream', device='drive0')
> +        self.assert_qmp(result, 'return', {})
> +
> +        completed = False
> +        while not completed:
> +            for event in self.vm.get_qmp_events(wait=True):
> +                if event['event'] == 'BLOCK_JOB_COMPLETED':
> +                    self.assert_qmp(event, 'data/type', 'stream')
> +                    self.assert_qmp(event, 'data/device', 'drive0')
> +                    self.assert_qmp(event, 'data/offset', self.image_len)
> +                    self.assert_qmp(event, 'data/len', self.image_len)
> +                    completed = True
> +
> +        self.assert_no_active_streams()
> +
> +        self.assertFalse('sectors not allocated' in qemu_io('-c', 'map', 
> 'test.qed'),
> +                         'image file not fully populated after streaming')
> +
> +    def test_device_not_found(self):
> +        result = self.vm.qmp('block_stream', device='nonexistent')
> +        self.assert_qmp(result, 'error/class', 'DeviceNotFound')
> +
> +class TestStreamStop(QMPTestCase):
> +    image_len = 8 * 1024 * 1024 * 1024 # GB
> +
> +    def setUp(self):
> +        qemu_img('create', 'backing.img', str(TestStreamStop.image_len))
> +        qemu_img('create', '-f', 'qed', '-o', 'backing_file=backing.img', 
> 'test.qed')
> +        self.vm = VM().add_drive('test.qed')
> +        self.vm.launch()
> +
> +    def tearDown(self):
> +        self.vm.shutdown()
> +        os.remove('test.qed')
> +        os.remove('backing.img')
> +
> +    def test_stream_stop(self):
> +        import time
> +
> +        self.assert_no_active_streams()
> +
> +        result = self.vm.qmp('block_stream', device='drive0')
> +        self.assert_qmp(result, 'return', {})
> +
> +        time.sleep(1)
> +        events = self.vm.get_qmp_events(wait=False)
> +        self.assertEqual(events, [], 'unexpected QMP event: %s' % events)
> +
> +        self.vm.qmp('block_job_cancel', device='drive0')
> +        self.assert_qmp(result, 'return', {})
> +
> +        cancelled = False
> +        while not cancelled:
> +            for event in self.vm.get_qmp_events(wait=True):
> +                if event['event'] == 'BLOCK_JOB_CANCELLED':
> +                    self.assert_qmp(event, 'data/type', 'stream')
> +                    self.assert_qmp(event, 'data/device', 'drive0')
> +                    cancelled = True
> +
> +        self.assert_no_active_streams()
> +
> +class TestSetSpeed(QMPTestCase):
> +    image_len = 80 * 1024 * 1024 # MB
> +
> +    def setUp(self):
> +        qemu_img('create', 'backing.img', str(TestSetSpeed.image_len))
> +        qemu_img('create', '-f', 'qed', '-o', 'backing_file=backing.img', 
> 'test.qed')
> +        self.vm = VM().add_drive('test.qed')
> +        self.vm.launch()
> +
> +    def tearDown(self):
> +        self.vm.shutdown()
> +        os.remove('test.qed')
> +        os.remove('backing.img')
> +
> +    # This doesn't print or verify anything, only use it via "test-stream.py 
> TestSetSpeed"
> +    def test_stream_set_speed(self):
> +        self.assert_no_active_streams()
> +
> +        result = self.vm.qmp('block_stream', device='drive0')
> +        self.assert_qmp(result, 'return', {})
> +
> +        result = self.vm.qmp('block_job_set_speed', device='drive0', value=8 
> * 1024 * 1024)
> +        self.assert_qmp(result, 'return', {})
> +
> +        completed = False
> +        while not completed:
> +            for event in self.vm.get_qmp_events(wait=True):
> +                if event['event'] == 'BLOCK_JOB_COMPLETED':
> +                    self.assert_qmp(event, 'data/type', 'stream')
> +                    self.assert_qmp(event, 'data/device', 'drive0')
> +                    self.assert_qmp(event, 'data/offset', self.image_len)
> +                    self.assert_qmp(event, 'data/len', self.image_len)
> +                    completed = True
> +
> +        self.assert_no_active_streams()
> +
> +if __name__ == '__main__':
> +    unittest.main()
> --
> 1.7.7.3
>
>