xref: /openbmc/qemu/tests/qemu-iotests/245 (revision 90bb6d67)
1#!/usr/bin/env python3
2# group: rw
3#
4# Test cases for the QMP 'blockdev-reopen' command
5#
6# Copyright (C) 2018-2019 Igalia, S.L.
7# Author: Alberto Garcia <berto@igalia.com>
8#
9# This program is free software; you can redistribute it and/or modify
10# it under the terms of the GNU General Public License as published by
11# the Free Software Foundation; either version 2 of the License, or
12# (at your option) any later version.
13#
14# This program is distributed in the hope that it will be useful,
15# but WITHOUT ANY WARRANTY; without even the implied warranty of
16# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17# GNU General Public License for more details.
18#
19# You should have received a copy of the GNU General Public License
20# along with this program.  If not, see <http://www.gnu.org/licenses/>.
21#
22
23import copy
24import json
25import os
26import re
27from subprocess import CalledProcessError
28
29import iotests
30from iotests import qemu_img, qemu_io
31
32hd_path = [
33    os.path.join(iotests.test_dir, 'hd0.img'),
34    os.path.join(iotests.test_dir, 'hd1.img'),
35    os.path.join(iotests.test_dir, 'hd2.img')
36]
37
38def hd_opts(idx):
39    return {'driver': iotests.imgfmt,
40            'node-name': 'hd%d' % idx,
41            'file': {'driver': 'file',
42                     'node-name': 'hd%d-file' % idx,
43                     'filename':  hd_path[idx] } }
44
45class TestBlockdevReopen(iotests.QMPTestCase):
46    total_io_cmds = 0
47
48    def setUp(self):
49        qemu_img('create', '-f', iotests.imgfmt, hd_path[0], '3M')
50        qemu_img('create', '-f', iotests.imgfmt, '-b', hd_path[0],
51                 '-F', iotests.imgfmt, hd_path[1])
52        qemu_img('create', '-f', iotests.imgfmt, hd_path[2], '3M')
53        qemu_io('-f', iotests.imgfmt, '-c', 'write -P 0xa0  0 1M', hd_path[0])
54        qemu_io('-f', iotests.imgfmt, '-c', 'write -P 0xa1 1M 1M', hd_path[1])
55        qemu_io('-f', iotests.imgfmt, '-c', 'write -P 0xa2 2M 1M', hd_path[2])
56        self.vm = iotests.VM()
57        self.vm.launch()
58
59    def tearDown(self):
60        self.vm.shutdown()
61        self.check_qemu_io_errors()
62        os.remove(hd_path[0])
63        os.remove(hd_path[1])
64        os.remove(hd_path[2])
65
66    # The output of qemu-io is not returned by vm.hmp_qemu_io() but
67    # it's stored in the log and can only be read when the VM has been
68    # shut down. This function runs qemu-io and keeps track of the
69    # number of times it's been called.
70    def run_qemu_io(self, img, cmd):
71        result = self.vm.hmp_qemu_io(img, cmd)
72        self.assert_qmp(result, 'return', '')
73        self.total_io_cmds += 1
74
75    # Once the VM is shut down we can parse the log and see if qemu-io
76    # ran without errors.
77    def check_qemu_io_errors(self):
78        self.assertFalse(self.vm.is_running())
79        found = 0
80        log = self.vm.get_log()
81        for line in log.split("\n"):
82            if line.startswith("Pattern verification failed"):
83                raise Exception("%s (command #%d)" % (line, found))
84            if re.match("(read|wrote) .*/.* bytes at offset", line):
85                found += 1
86        self.assertEqual(found, self.total_io_cmds,
87                         "Expected output of %d qemu-io commands, found %d" %
88                         (found, self.total_io_cmds))
89
90    # Run blockdev-reopen on a list of block devices
91    def reopenMultiple(self, opts, errmsg = None):
92        result = self.vm.qmp('blockdev-reopen', conv_keys=False, options=opts)
93        if errmsg:
94            self.assert_qmp(result, 'error/class', 'GenericError')
95            self.assert_qmp(result, 'error/desc', errmsg)
96        else:
97            self.assert_qmp(result, 'return', {})
98
99    # Run blockdev-reopen on a single block device (specified by
100    # 'opts') but applying 'newopts' on top of it. The original 'opts'
101    # dict is unmodified
102    def reopen(self, opts, newopts = {}, errmsg = None):
103        opts = copy.deepcopy(opts)
104
105        # Apply the changes from 'newopts' on top of 'opts'
106        for key in newopts:
107            value = newopts[key]
108            # If key has the form "foo.bar" then we need to do
109            # opts["foo"]["bar"] = value, not opts["foo.bar"] = value
110            subdict = opts
111            while key.find('.') != -1:
112                [prefix, key] = key.split('.', 1)
113                subdict = opts[prefix]
114            subdict[key] = value
115
116        self.reopenMultiple([ opts ], errmsg)
117
118
119    # Run query-named-block-nodes and return the specified entry
120    def get_node(self, node_name):
121        result = self.vm.qmp('query-named-block-nodes')
122        for node in result['return']:
123            if node['node-name'] == node_name:
124                return node
125        return None
126
127    # Run 'query-named-block-nodes' and compare its output with the
128    # value passed by the user in 'graph'
129    def check_node_graph(self, graph):
130        result = self.vm.qmp('query-named-block-nodes')
131        self.assertEqual(json.dumps(graph,  sort_keys=True),
132                         json.dumps(result, sort_keys=True))
133
134    # This test opens one single disk image (without backing files)
135    # and tries to reopen it with illegal / incorrect parameters.
136    def test_incorrect_parameters_single_file(self):
137        # Open 'hd0' only (no backing files)
138        opts = hd_opts(0)
139        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
140        original_graph = self.vm.qmp('query-named-block-nodes')
141
142        # We can reopen the image passing the same options
143        self.reopen(opts)
144
145        # We can also reopen passing a child reference in 'file'
146        self.reopen(opts, {'file': 'hd0-file'})
147
148        # We cannot change any of these
149        self.reopen(opts, {'node-name': 'not-found'}, "Failed to find node with node-name='not-found'")
150        self.reopen(opts, {'node-name': ''}, "Failed to find node with node-name=''")
151        self.reopen(opts, {'node-name': None}, "Invalid parameter type for 'options[0].node-name', expected: string")
152        self.reopen(opts, {'driver': 'raw'}, "Cannot change the option 'driver'")
153        self.reopen(opts, {'driver': ''}, "Parameter 'driver' does not accept value ''")
154        self.reopen(opts, {'driver': None}, "Invalid parameter type for 'options[0].driver', expected: string")
155        self.reopen(opts, {'file': 'not-found'}, "Cannot find device='' nor node-name='not-found'")
156        self.reopen(opts, {'file': ''}, "Cannot find device='' nor node-name=''")
157        self.reopen(opts, {'file': None}, "Invalid parameter type for 'file', expected: BlockdevRef")
158        self.reopen(opts, {'file.node-name': 'newname'}, "Cannot change the option 'node-name'")
159        self.reopen(opts, {'file.driver': 'host_device'}, "Cannot change the option 'driver'")
160        self.reopen(opts, {'file.filename': hd_path[1]}, "Cannot change the option 'filename'")
161        self.reopen(opts, {'file.aio': 'native'}, "Cannot change the option 'aio'")
162        self.reopen(opts, {'file.locking': 'off'}, "Cannot change the option 'locking'")
163        self.reopen(opts, {'file.filename': None}, "Invalid parameter type for 'options[0].file.filename', expected: string")
164
165        # node-name is optional in BlockdevOptions, but blockdev-reopen needs it
166        del opts['node-name']
167        self.reopen(opts, {}, "node-name not specified")
168
169        # Check that nothing has changed
170        self.check_node_graph(original_graph)
171
172        # Remove the node
173        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd0')
174
175    # This test opens an image with a backing file and tries to reopen
176    # it with illegal / incorrect parameters.
177    def test_incorrect_parameters_backing_file(self):
178        # Open hd1 omitting the backing options (hd0 will be opened
179        # with the default options)
180        opts = hd_opts(1)
181        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
182        original_graph = self.vm.qmp('query-named-block-nodes')
183
184        # We can't reopen the image passing the same options, 'backing' is mandatory
185        self.reopen(opts, {}, "backing is missing for 'hd1'")
186
187        # Everything works if we pass 'backing' using the existing node name
188        for node in original_graph['return']:
189            if node['drv'] == iotests.imgfmt and node['file'] == hd_path[0]:
190                backing_node_name = node['node-name']
191        self.reopen(opts, {'backing': backing_node_name})
192
193        # We can't use a non-existing or empty (non-NULL) node as the backing image
194        self.reopen(opts, {'backing': 'not-found'}, "Cannot find device=\'\' nor node-name=\'not-found\'")
195        self.reopen(opts, {'backing': ''}, "Cannot find device=\'\' nor node-name=\'\'")
196
197        # We can reopen the image just fine if we specify the backing options
198        opts['backing'] = {'driver': iotests.imgfmt,
199                           'file': {'driver': 'file',
200                                    'filename': hd_path[0]}}
201        self.reopen(opts)
202
203        # We cannot change any of these options
204        self.reopen(opts, {'backing.node-name': 'newname'}, "Cannot change the option 'node-name'")
205        self.reopen(opts, {'backing.driver': 'raw'}, "Cannot change the option 'driver'")
206        self.reopen(opts, {'backing.file.node-name': 'newname'}, "Cannot change the option 'node-name'")
207        self.reopen(opts, {'backing.file.driver': 'host_device'}, "Cannot change the option 'driver'")
208
209        # Check that nothing has changed since the beginning
210        self.check_node_graph(original_graph)
211
212        # Remove the node
213        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd1')
214
215    # Reopen an image several times changing some of its options
216    def test_reopen(self):
217        try:
218            qemu_io('-f', 'raw', '-t', 'none', '-c', 'quit', hd_path[0])
219            supports_direct = True
220        except CalledProcessError as exc:
221            if 'O_DIRECT' in exc.stdout:
222                supports_direct = False
223            else:
224                raise
225
226        # Open the hd1 image passing all backing options
227        opts = hd_opts(1)
228        opts['backing'] = hd_opts(0)
229        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
230        original_graph = self.vm.qmp('query-named-block-nodes')
231
232        # We can reopen the image passing the same options
233        self.reopen(opts)
234
235        # Reopen in read-only mode
236        self.assert_qmp(self.get_node('hd1'), 'ro', False)
237
238        self.reopen(opts, {'read-only': True})
239        self.assert_qmp(self.get_node('hd1'), 'ro', True)
240        self.reopen(opts)
241        self.assert_qmp(self.get_node('hd1'), 'ro', False)
242
243        # Change the cache options
244        self.assert_qmp(self.get_node('hd1'), 'cache/writeback', True)
245        self.assert_qmp(self.get_node('hd1'), 'cache/direct', False)
246        self.assert_qmp(self.get_node('hd1'), 'cache/no-flush', False)
247        self.reopen(opts, {'cache': { 'direct': supports_direct, 'no-flush': True }})
248        self.assert_qmp(self.get_node('hd1'), 'cache/writeback', True)
249        self.assert_qmp(self.get_node('hd1'), 'cache/direct', supports_direct)
250        self.assert_qmp(self.get_node('hd1'), 'cache/no-flush', True)
251
252        # Reopen again with the original options
253        self.reopen(opts)
254        self.assert_qmp(self.get_node('hd1'), 'cache/writeback', True)
255        self.assert_qmp(self.get_node('hd1'), 'cache/direct', False)
256        self.assert_qmp(self.get_node('hd1'), 'cache/no-flush', False)
257
258        # Change 'detect-zeroes' and 'discard'
259        self.assert_qmp(self.get_node('hd1'), 'detect_zeroes', 'off')
260        self.reopen(opts, {'detect-zeroes': 'on'})
261        self.assert_qmp(self.get_node('hd1'), 'detect_zeroes', 'on')
262        self.reopen(opts, {'detect-zeroes': 'unmap'},
263                    "setting detect-zeroes to unmap is not allowed " +
264                    "without setting discard operation to unmap")
265        self.assert_qmp(self.get_node('hd1'), 'detect_zeroes', 'on')
266        self.reopen(opts, {'detect-zeroes': 'unmap', 'discard': 'unmap'})
267        self.assert_qmp(self.get_node('hd1'), 'detect_zeroes', 'unmap')
268        self.reopen(opts)
269        self.assert_qmp(self.get_node('hd1'), 'detect_zeroes', 'off')
270
271        # Changing 'force-share' is currently not supported
272        self.reopen(opts, {'force-share': True}, "Cannot change the option 'force-share'")
273
274        # Change some qcow2-specific options
275        # No way to test for success other than checking the return message
276        if iotests.imgfmt == 'qcow2':
277            self.reopen(opts, {'l2-cache-entry-size': 128 * 1024},
278                        "L2 cache entry size must be a power of two "+
279                        "between 512 and the cluster size (65536)")
280            self.reopen(opts, {'l2-cache-size': 1024 * 1024,
281                               'cache-size':     512 * 1024},
282                        "l2-cache-size may not exceed cache-size")
283            self.reopen(opts, {'l2-cache-size':        4 * 1024 * 1024,
284                               'refcount-cache-size':  4 * 1024 * 1024,
285                               'l2-cache-entry-size': 32 * 1024})
286            self.reopen(opts, {'pass-discard-request': True})
287
288        # Check that nothing has changed since the beginning
289        # (from the parameters that we can check)
290        self.check_node_graph(original_graph)
291
292        # Check that the node names (other than the top-level one) are optional
293        del opts['file']['node-name']
294        del opts['backing']['node-name']
295        del opts['backing']['file']['node-name']
296        self.reopen(opts)
297        self.check_node_graph(original_graph)
298
299        # Reopen setting backing = null, this removes the backing image from the chain
300        self.reopen(opts, {'backing': None})
301        self.assert_qmp_absent(self.get_node('hd1'), 'image/backing-image')
302
303        # Open the 'hd0' image
304        self.vm.cmd('blockdev-add', conv_keys = False, **hd_opts(0))
305
306        # Reopen the hd1 image setting 'hd0' as its backing image
307        self.reopen(opts, {'backing': 'hd0'})
308        self.assert_qmp(self.get_node('hd1'), 'image/backing-image/filename', hd_path[0])
309
310        # Check that nothing has changed since the beginning
311        self.reopen(hd_opts(0), {'read-only': True})
312        self.check_node_graph(original_graph)
313
314        # The backing file (hd0) is now a reference, we cannot change backing.* anymore
315        self.reopen(opts, {}, "Cannot change the option 'backing.driver'")
316
317        # We can't remove 'hd0' while it's a backing image of 'hd1'
318        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'hd0')
319        self.assert_qmp(result, 'error/class', 'GenericError')
320        self.assert_qmp(result, 'error/desc', "Node 'hd0' is busy: node is used as backing hd of 'hd1'")
321
322        # But we can remove both nodes if done in the proper order
323        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd1')
324        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd0')
325
326    # Reopen a raw image and see the effect of changing the 'offset' option
327    def test_reopen_raw(self):
328        opts = {'driver': 'raw', 'node-name': 'hd0',
329                'file': { 'driver': 'file',
330                          'filename': hd_path[0],
331                          'node-name': 'hd0-file' } }
332
333        # First we create a 2MB raw file, and fill each half with a
334        # different value
335        qemu_img('create', '-f', 'raw', hd_path[0], '2M')
336        qemu_io('-f', 'raw', '-c', 'write -P 0xa0  0 1M', hd_path[0])
337        qemu_io('-f', 'raw', '-c', 'write -P 0xa1 1M 1M', hd_path[0])
338
339        # Open the raw file with QEMU
340        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
341
342        # Read 1MB from offset 0
343        self.run_qemu_io("hd0", "read -P 0xa0  0 1M")
344
345        # Reopen the image with a 1MB offset.
346        # Now the results are different
347        self.reopen(opts, {'offset': 1024*1024})
348        self.run_qemu_io("hd0", "read -P 0xa1  0 1M")
349
350        # Reopen again with the original options.
351        # We get the original results again
352        self.reopen(opts)
353        self.run_qemu_io("hd0", "read -P 0xa0  0 1M")
354
355        # Remove the block device
356        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd0')
357
358    # Omitting an option should reset it to the default value, but if
359    # an option cannot be changed it shouldn't be possible to reset it
360    # to its default value either
361    def test_reset_default_values(self):
362        opts = {'driver': 'qcow2', 'node-name': 'hd0',
363                'file': { 'driver': 'file',
364                          'filename': hd_path[0],
365                          'x-check-cache-dropped': True, # This one can be changed
366                          'locking': 'off',              # This one can NOT be changed
367                          'node-name': 'hd0-file' } }
368
369        # Open the file with QEMU
370        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
371
372        # file.x-check-cache-dropped can be changed...
373        self.reopen(opts, { 'file.x-check-cache-dropped': False })
374        # ...and dropped completely (resetting to the default value)
375        del opts['file']['x-check-cache-dropped']
376        self.reopen(opts)
377
378        # file.locking cannot be changed nor reset to the default value
379        self.reopen(opts, { 'file.locking': 'on' }, "Cannot change the option 'locking'")
380        del opts['file']['locking']
381        self.reopen(opts, {}, "Option 'locking' cannot be reset to its default value")
382        # But we can reopen it if we maintain its previous value
383        self.reopen(opts, { 'file.locking': 'off' })
384
385        # Remove the block device
386        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd0')
387
388    # This test modifies the node graph a few times by changing the
389    # 'backing' option on reopen and verifies that the guest data that
390    # is read afterwards is consistent with the graph changes.
391    def test_io_with_graph_changes(self):
392        opts = []
393
394        # Open hd0, hd1 and hd2 without any backing image
395        for i in range(3):
396            opts.append(hd_opts(i))
397            opts[i]['backing'] = None
398            self.vm.cmd('blockdev-add', conv_keys = False, **opts[i])
399
400        # hd0
401        self.run_qemu_io("hd0", "read -P 0xa0  0 1M")
402        self.run_qemu_io("hd0", "read -P 0    1M 1M")
403        self.run_qemu_io("hd0", "read -P 0    2M 1M")
404
405        # hd1 <- hd0
406        self.reopen(opts[0], {'backing': 'hd1'})
407
408        self.run_qemu_io("hd0", "read -P 0xa0  0 1M")
409        self.run_qemu_io("hd0", "read -P 0xa1 1M 1M")
410        self.run_qemu_io("hd0", "read -P 0    2M 1M")
411
412        # hd1 <- hd0 , hd1 <- hd2
413        self.reopen(opts[2], {'backing': 'hd1'})
414
415        self.run_qemu_io("hd2", "read -P 0     0 1M")
416        self.run_qemu_io("hd2", "read -P 0xa1 1M 1M")
417        self.run_qemu_io("hd2", "read -P 0xa2 2M 1M")
418
419        # hd1 <- hd2 <- hd0
420        self.reopen(opts[0], {'backing': 'hd2'})
421
422        self.run_qemu_io("hd0", "read -P 0xa0  0 1M")
423        self.run_qemu_io("hd0", "read -P 0xa1 1M 1M")
424        self.run_qemu_io("hd0", "read -P 0xa2 2M 1M")
425
426        # hd2 <- hd0
427        self.reopen(opts[2], {'backing': None})
428
429        self.run_qemu_io("hd0", "read -P 0xa0  0 1M")
430        self.run_qemu_io("hd0", "read -P 0    1M 1M")
431        self.run_qemu_io("hd0", "read -P 0xa2 2M 1M")
432
433        # hd2 <- hd1 <- hd0
434        self.reopen(opts[1], {'backing': 'hd2'})
435        self.reopen(opts[0], {'backing': 'hd1'})
436
437        self.run_qemu_io("hd0", "read -P 0xa0  0 1M")
438        self.run_qemu_io("hd0", "read -P 0xa1 1M 1M")
439        self.run_qemu_io("hd0", "read -P 0xa2 2M 1M")
440
441        # Illegal operation: hd2 is a child of hd1
442        self.reopen(opts[2], {'backing': 'hd1'},
443                    "Making 'hd1' a backing child of 'hd2' would create a cycle")
444
445        # hd2 <- hd0, hd2 <- hd1
446        self.reopen(opts[0], {'backing': 'hd2'})
447
448        self.run_qemu_io("hd1", "read -P 0     0 1M")
449        self.run_qemu_io("hd1", "read -P 0xa1 1M 1M")
450        self.run_qemu_io("hd1", "read -P 0xa2 2M 1M")
451
452        # More illegal operations
453        self.reopen(opts[2], {'backing': 'hd1'},
454                    "Making 'hd1' a backing child of 'hd2' would create a cycle")
455        self.reopen(opts[2], {'file': 'hd0-file'},
456                    "Permission conflict on node 'hd0-file': permissions 'write, resize' are both required by node 'hd0' (uses node 'hd0-file' as 'file' child) and unshared by node 'hd2' (uses node 'hd0-file' as 'file' child).")
457
458        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'hd2')
459        self.assert_qmp(result, 'error/class', 'GenericError')
460        self.assert_qmp(result, 'error/desc', "Node 'hd2' is busy: node is used as backing hd of 'hd0'")
461
462        # hd1 doesn't have a backing file now
463        self.reopen(opts[1], {'backing': None})
464
465        self.run_qemu_io("hd1", "read -P 0     0 1M")
466        self.run_qemu_io("hd1", "read -P 0xa1 1M 1M")
467        self.run_qemu_io("hd1", "read -P 0    2M 1M")
468
469        # We can't remove the 'backing' option if the image has a
470        # default backing file
471        del opts[1]['backing']
472        self.reopen(opts[1], {}, "backing is missing for 'hd1'")
473
474        self.run_qemu_io("hd1", "read -P 0     0 1M")
475        self.run_qemu_io("hd1", "read -P 0xa1 1M 1M")
476        self.run_qemu_io("hd1", "read -P 0    2M 1M")
477
478    # This test verifies that we can't change the children of a block
479    # device during a reopen operation in a way that would create
480    # cycles in the node graph
481    @iotests.skip_if_unsupported(['blkverify'])
482    def test_graph_cycles(self):
483        opts = []
484
485        # Open all three images without backing file
486        for i in range(3):
487            opts.append(hd_opts(i))
488            opts[i]['backing'] = None
489            self.vm.cmd('blockdev-add', conv_keys = False, **opts[i])
490
491        # hd1 <- hd0, hd1 <- hd2
492        self.reopen(opts[0], {'backing': 'hd1'})
493        self.reopen(opts[2], {'backing': 'hd1'})
494
495        # Illegal: hd2 is backed by hd1
496        self.reopen(opts[1], {'backing': 'hd2'},
497                    "Making 'hd2' a backing child of 'hd1' would create a cycle")
498
499        # hd1 <- hd0 <- hd2
500        self.reopen(opts[2], {'backing': 'hd0'})
501
502        # Illegal: hd2 is backed by hd0, which is backed by hd1
503        self.reopen(opts[1], {'backing': 'hd2'},
504                    "Making 'hd2' a backing child of 'hd1' would create a cycle")
505
506        # Illegal: hd1 cannot point to itself
507        self.reopen(opts[1], {'backing': 'hd1'},
508                    "Making 'hd1' a backing child of 'hd1' would create a cycle")
509
510        # Remove all backing files
511        self.reopen(opts[0])
512        self.reopen(opts[2])
513
514        ##########################################
515        # Add a blkverify node using hd0 and hd1 #
516        ##########################################
517        bvopts = {'driver': 'blkverify',
518                  'node-name': 'bv',
519                  'test': 'hd0',
520                  'raw': 'hd1'}
521        self.vm.cmd('blockdev-add', conv_keys = False, **bvopts)
522
523        # blkverify doesn't currently allow reopening. TODO: implement this
524        self.reopen(bvopts, {}, "Block format 'blkverify' used by node 'bv'" +
525                    " does not support reopening files")
526
527        # Illegal: hd0 is a child of the blkverify node
528        self.reopen(opts[0], {'backing': 'bv'},
529                    "Making 'bv' a backing child of 'hd0' would create a cycle")
530
531        # Delete the blkverify node
532        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'bv')
533
534    # Replace the protocol layer ('file' parameter) of a disk image
535    def test_replace_file(self):
536        # Create two small raw images and add them to a running VM
537        qemu_img('create', '-f', 'raw', hd_path[0], '10k')
538        qemu_img('create', '-f', 'raw', hd_path[1], '10k')
539
540        hd0_opts = {'driver': 'file', 'node-name': 'hd0-file', 'filename':  hd_path[0] }
541        hd1_opts = {'driver': 'file', 'node-name': 'hd1-file', 'filename':  hd_path[1] }
542
543        self.vm.cmd('blockdev-add', conv_keys = False, **hd0_opts)
544        self.vm.cmd('blockdev-add', conv_keys = False, **hd1_opts)
545
546        # Add a raw format layer that uses hd0-file as its protocol layer
547        opts = {'driver': 'raw', 'node-name': 'hd', 'file': 'hd0-file'}
548
549        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
550
551        # Fill the image with data
552        self.run_qemu_io("hd", "read  -P 0 0 10k")
553        self.run_qemu_io("hd", "write -P 0xa0 0 10k")
554
555        # Replace hd0-file with hd1-file and fill it with (different) data
556        self.reopen(opts, {'file': 'hd1-file'})
557        self.run_qemu_io("hd", "read  -P 0 0 10k")
558        self.run_qemu_io("hd", "write -P 0xa1 0 10k")
559
560        # Use hd0-file again and check that it contains the expected data
561        self.reopen(opts, {'file': 'hd0-file'})
562        self.run_qemu_io("hd", "read  -P 0xa0 0 10k")
563
564        # And finally do the same with hd1-file
565        self.reopen(opts, {'file': 'hd1-file'})
566        self.run_qemu_io("hd", "read  -P 0xa1 0 10k")
567
568    # Insert (and remove) a throttle filter
569    def test_insert_throttle_filter(self):
570        # Add an image to the VM
571        hd0_opts = hd_opts(0)
572        self.vm.cmd('blockdev-add', conv_keys = False, **hd0_opts)
573
574        # Create a throttle-group object
575        opts = { 'qom-type': 'throttle-group', 'id': 'group0',
576                 'limits': { 'iops-total': 1000 } }
577        self.vm.cmd('object-add', conv_keys = False, **opts)
578
579        # Add a throttle filter with the group that we just created.
580        # The filter is not used by anyone yet
581        opts = { 'driver': 'throttle', 'node-name': 'throttle0',
582                 'throttle-group': 'group0', 'file': 'hd0-file' }
583        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
584
585        # Insert the throttle filter between hd0 and hd0-file
586        self.reopen(hd0_opts, {'file': 'throttle0'})
587
588        # Remove the throttle filter from hd0
589        self.reopen(hd0_opts, {'file': 'hd0-file'})
590
591    # Insert (and remove) a compress filter
592    @iotests.skip_if_unsupported(['compress'])
593    def test_insert_compress_filter(self):
594        # Add an image to the VM: hd (raw) -> hd0 (qcow2) -> hd0-file (file)
595        opts = {'driver': 'raw', 'node-name': 'hd', 'file': hd_opts(0)}
596        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
597
598        # Add a 'compress' filter
599        filter_opts = {'driver': 'compress',
600                       'node-name': 'compress0',
601                       'file': 'hd0'}
602        self.vm.cmd('blockdev-add', conv_keys = False, **filter_opts)
603
604        # Unmap the beginning of the image (we cannot write compressed
605        # data to an allocated cluster)
606        self.run_qemu_io("hd", "write -z -u 0 128k")
607
608        # Write data to the first cluster
609        self.run_qemu_io("hd", "write -P 0xa0 0 64k")
610
611        # Insert the filter then write to the second cluster
612        # hd -> compress0 -> hd0 -> hd0-file
613        self.reopen(opts, {'file': 'compress0'})
614        self.run_qemu_io("hd", "write -P 0xa1 64k 64k")
615
616        # Remove the filter then write to the third cluster
617        # hd -> hd0 -> hd0-file
618        self.reopen(opts, {'file': 'hd0'})
619        self.run_qemu_io("hd", "write -P 0xa2 128k 64k")
620
621        # Verify the data that we just wrote
622        self.run_qemu_io("hd", "read -P 0xa0    0 64k")
623        self.run_qemu_io("hd", "read -P 0xa1  64k 64k")
624        self.run_qemu_io("hd", "read -P 0xa2 128k 64k")
625
626        self.vm.shutdown()
627
628        # Check the first byte of the first three L2 entries and verify that
629        # the second one is compressed (0x40) while the others are not (0x80)
630        iotests.qemu_io('-f', 'raw', '-c', 'read -P 0x80 0x40000 1',
631                                     '-c', 'read -P 0x40 0x40008 1',
632                                     '-c', 'read -P 0x80 0x40010 1', hd_path[0])
633
634    # Swap the disk images of two active block devices
635    def test_swap_files(self):
636        # Add hd0 and hd2 (none of them with backing files)
637        opts0 = hd_opts(0)
638        self.vm.cmd('blockdev-add', conv_keys = False, **opts0)
639
640        opts2 = hd_opts(2)
641        self.vm.cmd('blockdev-add', conv_keys = False, **opts2)
642
643        # Write different data to both block devices
644        self.run_qemu_io("hd0", "write -P 0xa0 0 1k")
645        self.run_qemu_io("hd2", "write -P 0xa2 0 1k")
646
647        # Check that the data reads correctly
648        self.run_qemu_io("hd0", "read  -P 0xa0 0 1k")
649        self.run_qemu_io("hd2", "read  -P 0xa2 0 1k")
650
651        # It's not possible to make a block device use an image that
652        # is already being used by the other device.
653        self.reopen(opts0, {'file': 'hd2-file'},
654                    "Permission conflict on node 'hd2-file': permissions "
655                    "'write, resize' are both required by node 'hd2' (uses "
656                    "node 'hd2-file' as 'file' child) and unshared by node "
657                    "'hd0' (uses node 'hd2-file' as 'file' child).")
658        self.reopen(opts2, {'file': 'hd0-file'},
659                    "Permission conflict on node 'hd0-file': permissions "
660                    "'write, resize' are both required by node 'hd0' (uses "
661                    "node 'hd0-file' as 'file' child) and unshared by node "
662                    "'hd2' (uses node 'hd0-file' as 'file' child).")
663
664        # But we can swap the images if we reopen both devices at the
665        # same time
666        opts0['file'] = 'hd2-file'
667        opts2['file'] = 'hd0-file'
668        self.reopenMultiple([opts0, opts2])
669        self.run_qemu_io("hd0", "read  -P 0xa2 0 1k")
670        self.run_qemu_io("hd2", "read  -P 0xa0 0 1k")
671
672        # And we can of course come back to the original state
673        opts0['file'] = 'hd0-file'
674        opts2['file'] = 'hd2-file'
675        self.reopenMultiple([opts0, opts2])
676        self.run_qemu_io("hd0", "read  -P 0xa0 0 1k")
677        self.run_qemu_io("hd2", "read  -P 0xa2 0 1k")
678
679    # Misc reopen tests with different block drivers
680    @iotests.skip_if_unsupported(['quorum', 'throttle'])
681    def test_misc_drivers(self):
682        ####################
683        ###### quorum ######
684        ####################
685        for i in range(3):
686            opts = hd_opts(i)
687            # Open all three images without backing file
688            opts['backing'] = None
689            self.vm.cmd('blockdev-add', conv_keys = False, **opts)
690
691        opts = {'driver': 'quorum',
692                'node-name': 'quorum0',
693                'children': ['hd0', 'hd1', 'hd2'],
694                'vote-threshold': 2}
695        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
696
697        # Quorum doesn't currently allow reopening. TODO: implement this
698        self.reopen(opts, {}, "Block format 'quorum' used by node 'quorum0'" +
699                    " does not support reopening files")
700
701        # You can't make quorum0 a backing file of hd0:
702        # hd0 is already a child of quorum0.
703        self.reopen(hd_opts(0), {'backing': 'quorum0'},
704                    "Making 'quorum0' a backing child of 'hd0' would create a cycle")
705
706        # Delete quorum0
707        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'quorum0')
708
709        # Delete hd0, hd1 and hd2
710        for i in range(3):
711            self.vm.cmd('blockdev-del', conv_keys = True,
712                        node_name = 'hd%d' % i)
713
714        ######################
715        ###### blkdebug ######
716        ######################
717        opts = {'driver': 'blkdebug',
718                'node-name': 'bd',
719                'config': '/dev/null',
720                'image': hd_opts(0)}
721        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
722
723        # blkdebug allows reopening if we keep the same options
724        self.reopen(opts)
725
726        # but it currently does not allow changes
727        self.reopen(opts, {'image': 'hd1'}, "Cannot change the option 'image'")
728        self.reopen(opts, {'align': 33554432}, "Cannot change the option 'align'")
729        self.reopen(opts, {'config': '/non/existent'}, "Cannot change the option 'config'")
730        del opts['config']
731        self.reopen(opts, {}, "Option 'config' cannot be reset to its default value")
732
733        # Delete the blkdebug node
734        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'bd')
735
736        ##################
737        ###### null ######
738        ##################
739        opts = {'driver': 'null-co', 'node-name': 'root', 'size': 1024}
740
741        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
742
743        # 1 << 30 is the default value, but we cannot change it explicitly
744        self.reopen(opts, {'size': (1 << 30)}, "Cannot change the option 'size'")
745
746        # We cannot change 'size' back to its default value either
747        del opts['size']
748        self.reopen(opts, {}, "Option 'size' cannot be reset to its default value")
749
750        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'root')
751
752        ##################
753        ###### file ######
754        ##################
755        opts = hd_opts(0)
756        opts['file']['locking'] = 'on'
757        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
758
759        # 'locking' cannot be changed
760        del opts['file']['locking']
761        self.reopen(opts, {'file.locking': 'on'})
762        self.reopen(opts, {'file.locking': 'off'}, "Cannot change the option 'locking'")
763        self.reopen(opts, {}, "Option 'locking' cannot be reset to its default value")
764
765        # Trying to reopen the 'file' node directly does not make a difference
766        opts = opts['file']
767        self.reopen(opts, {'locking': 'on'})
768        self.reopen(opts, {'locking': 'off'}, "Cannot change the option 'locking'")
769        self.reopen(opts, {}, "Option 'locking' cannot be reset to its default value")
770
771        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd0')
772
773        ######################
774        ###### throttle ######
775        ######################
776        opts = { 'qom-type': 'throttle-group', 'id': 'group0',
777                 'limits': { 'iops-total': 1000 } }
778        self.vm.cmd('object-add', conv_keys = False, **opts)
779
780        opts = { 'qom-type': 'throttle-group', 'id': 'group1',
781                 'limits': { 'iops-total': 2000 } }
782        self.vm.cmd('object-add', conv_keys = False, **opts)
783
784        # Add a throttle filter with group = group0
785        opts = { 'driver': 'throttle', 'node-name': 'throttle0',
786                 'throttle-group': 'group0', 'file': hd_opts(0) }
787        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
788
789        # We can reopen it if we keep the same options
790        self.reopen(opts)
791
792        # We can also reopen if 'file' is a reference to the child
793        self.reopen(opts, {'file': 'hd0'})
794
795        # This is illegal
796        self.reopen(opts, {'throttle-group': 'notfound'}, "Throttle group 'notfound' does not exist")
797
798        # But it's possible to change the group to group1
799        self.reopen(opts, {'throttle-group': 'group1'})
800
801        # Now group1 is in use, it cannot be deleted
802        result = self.vm.qmp('object-del', id = 'group1')
803        self.assert_qmp(result, 'error/class', 'GenericError')
804        self.assert_qmp(result, 'error/desc', "object 'group1' is in use, can not be deleted")
805
806        # Default options, this switches the group back to group0
807        self.reopen(opts)
808
809        # So now we cannot delete group0
810        result = self.vm.qmp('object-del', id = 'group0')
811        self.assert_qmp(result, 'error/class', 'GenericError')
812        self.assert_qmp(result, 'error/desc', "object 'group0' is in use, can not be deleted")
813
814        # But group1 is free this time, and it can be deleted
815        self.vm.cmd('object-del', id = 'group1')
816
817        # Let's delete the filter node
818        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'throttle0')
819
820        # And we can finally get rid of group0
821        self.vm.cmd('object-del', id = 'group0')
822
823    # If an image has a backing file then the 'backing' option must be
824    # passed on reopen. We don't allow leaving the option out in this
825    # case because it's unclear what the correct semantics would be.
826    def test_missing_backing_options_1(self):
827        # hd2
828        opts = hd_opts(2)
829        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
830
831        # hd0
832        opts = hd_opts(0)
833        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
834
835        # hd0 has no backing file: we can omit the 'backing' option
836        self.reopen(opts)
837
838        # hd2 <- hd0
839        self.reopen(opts, {'backing': 'hd2'})
840
841        # hd0 has a backing file: we must set the 'backing' option
842        self.reopen(opts, {}, "backing is missing for 'hd0'")
843
844        # hd2 can't be removed because it's the backing file of hd0
845        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'hd2')
846        self.assert_qmp(result, 'error/class', 'GenericError')
847        self.assert_qmp(result, 'error/desc', "Node 'hd2' is busy: node is used as backing hd of 'hd0'")
848
849        # Detach hd2 from hd0.
850        self.reopen(opts, {'backing': None})
851
852        # Without a backing file, we can omit 'backing' again
853        self.reopen(opts)
854
855        # Remove both hd0 and hd2
856        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd0')
857
858        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd2')
859
860    # If an image has default backing file (as part of its metadata)
861    # then the 'backing' option must be passed on reopen. We don't
862    # allow leaving the option out in this case because it's unclear
863    # what the correct semantics would be.
864    def test_missing_backing_options_2(self):
865        # hd0 <- hd1
866        # (hd0 is hd1's default backing file)
867        opts = hd_opts(1)
868        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
869
870        # hd1 has a backing file: we can't omit the 'backing' option
871        self.reopen(opts, {}, "backing is missing for 'hd1'")
872
873        # Let's detach the backing file
874        self.reopen(opts, {'backing': None})
875
876        # No backing file attached to hd1 now, but we still can't omit the 'backing' option
877        self.reopen(opts, {}, "backing is missing for 'hd1'")
878
879        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd1')
880
881    # Test that making 'backing' a reference to an existing child
882    # keeps its current options
883    def test_backing_reference(self):
884        # hd2 <- hd1 <- hd0
885        opts = hd_opts(0)
886        opts['backing'] = hd_opts(1)
887        opts['backing']['backing'] = hd_opts(2)
888        # Enable 'detect-zeroes' on all three nodes
889        opts['detect-zeroes'] = 'on'
890        opts['backing']['detect-zeroes'] = 'on'
891        opts['backing']['backing']['detect-zeroes'] = 'on'
892        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
893
894        # Reopen the chain passing the minimum amount of required options.
895        # By making 'backing' a reference to hd1 (instead of a sub-dict)
896        # we tell QEMU to keep its current set of options.
897        opts = {'driver': iotests.imgfmt,
898                'node-name': 'hd0',
899                'file': 'hd0-file',
900                'backing': 'hd1' }
901        self.reopen(opts)
902
903        # This has reset 'detect-zeroes' on hd0, but not on hd1 and hd2.
904        self.assert_qmp(self.get_node('hd0'), 'detect_zeroes', 'off')
905        self.assert_qmp(self.get_node('hd1'), 'detect_zeroes', 'on')
906        self.assert_qmp(self.get_node('hd2'), 'detect_zeroes', 'on')
907
908    # Test what happens if the graph changes due to other operations
909    # such as block-stream
910    def test_block_stream_1(self):
911        # hd1 <- hd0
912        opts = hd_opts(0)
913        opts['backing'] = hd_opts(1)
914        opts['backing']['backing'] = None
915        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
916
917        # Stream hd1 into hd0 and wait until it's done
918        self.vm.cmd('block-stream', conv_keys = True, job_id = 'stream0', device = 'hd0')
919        self.wait_until_completed(drive = 'stream0')
920
921        # Now we have only hd0
922        self.assertEqual(self.get_node('hd1'), None)
923
924        # We have backing.* options but there's no backing file anymore
925        self.reopen(opts, {}, "Cannot change the option 'backing.driver'")
926
927        # If we remove the 'backing' option then we can reopen hd0 just fine
928        del opts['backing']
929        self.reopen(opts)
930
931        # We can also reopen hd0 if we set 'backing' to null
932        self.reopen(opts, {'backing': None})
933
934        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd0')
935
936    # Another block_stream test
937    def test_block_stream_2(self):
938        # hd2 <- hd1 <- hd0
939        opts = hd_opts(0)
940        opts['backing'] = hd_opts(1)
941        opts['backing']['backing'] = hd_opts(2)
942        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
943
944        # Stream hd1 into hd0 and wait until it's done
945        self.vm.cmd('block-stream', conv_keys = True, job_id = 'stream0',
946                    device = 'hd0', base_node = 'hd2')
947        self.wait_until_completed(drive = 'stream0')
948
949        # The chain is hd2 <- hd0 now. hd1 is missing
950        self.assertEqual(self.get_node('hd1'), None)
951
952        # The backing options in the dict were meant for hd1, but we cannot
953        # use them with hd2 because hd1 had a backing file while hd2 does not.
954        self.reopen(opts, {}, "Cannot change the option 'backing.driver'")
955
956        # If we remove hd1's options from the dict then things work fine
957        opts['backing'] = opts['backing']['backing']
958        self.reopen(opts)
959
960        # We can also reopen hd0 if we use a reference to the backing file
961        self.reopen(opts, {'backing': 'hd2'})
962
963        # But we cannot leave the option out
964        del opts['backing']
965        self.reopen(opts, {}, "backing is missing for 'hd0'")
966
967        # Now we can delete hd0 (and hd2)
968        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd0')
969        self.assertEqual(self.get_node('hd2'), None)
970
971    # Reopen the chain during a block-stream job (from hd1 to hd0)
972    def test_block_stream_3(self):
973        # hd2 <- hd1 <- hd0
974        opts = hd_opts(0)
975        opts['backing'] = hd_opts(1)
976        opts['backing']['backing'] = hd_opts(2)
977        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
978
979        # hd2 <- hd0
980        self.vm.cmd('block-stream', conv_keys = True, job_id = 'stream0',
981                    device = 'hd0', base_node = 'hd2',
982                    auto_finalize = False)
983
984        # We can remove hd2 while the stream job is ongoing
985        opts['backing']['backing'] = None
986        self.reopen(opts, {})
987
988        # We can't remove hd1 while the stream job is ongoing
989        opts['backing'] = None
990        self.reopen(opts, {}, "Cannot change frozen 'backing' link from 'hd0' to 'hd1'")
991
992        self.vm.run_job('stream0', auto_finalize = False, auto_dismiss = True)
993
994    # Reopen the chain during a block-stream job (from hd2 to hd1)
995    def test_block_stream_4(self):
996        # hd2 <- hd1 <- hd0
997        opts = hd_opts(0)
998        opts['backing'] = hd_opts(1)
999        opts['backing']['backing'] = hd_opts(2)
1000        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
1001
1002        # hd1 <- hd0
1003        self.vm.cmd('block-stream', conv_keys = True, job_id = 'stream0',
1004                    device = 'hd1', filter_node_name='cor',
1005                    auto_finalize = False)
1006
1007        # We can't reopen with the original options because there is a filter
1008        # inserted by stream job above hd1.
1009        self.reopen(opts, {},
1010                    "Cannot change the option 'backing.backing.file.node-name'")
1011
1012        # We can't reopen hd1 to read-only, as block-stream requires it to be
1013        # read-write
1014        self.reopen(opts['backing'], {'read-only': True},
1015                    "Read-only block node 'hd1' cannot support read-write users")
1016
1017        # We can't remove hd2 while the stream job is ongoing
1018        opts['backing']['backing'] = None
1019        self.reopen(opts['backing'], {'read-only': False},
1020                    "Cannot change frozen 'backing' link from 'hd1' to 'hd2'")
1021
1022        # We can detach hd1 from hd0 because it doesn't affect the stream job
1023        opts['backing'] = None
1024        self.reopen(opts)
1025
1026        self.vm.run_job('stream0', auto_finalize = False, auto_dismiss = True)
1027
1028    # Reopen the chain during a block-commit job (from hd0 to hd2)
1029    def test_block_commit_1(self):
1030        # hd2 <- hd1 <- hd0
1031        opts = hd_opts(0)
1032        opts['backing'] = hd_opts(1)
1033        opts['backing']['backing'] = hd_opts(2)
1034        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
1035
1036        self.vm.cmd('block-commit', conv_keys = True, job_id = 'commit0',
1037                    device = 'hd0')
1038
1039        # We can't remove hd2 while the commit job is ongoing
1040        opts['backing']['backing'] = None
1041        self.reopen(opts, {}, "Cannot change frozen 'backing' link from 'hd1' to 'hd2'")
1042
1043        # We can't remove hd1 while the commit job is ongoing
1044        opts['backing'] = None
1045        self.reopen(opts, {}, "Cannot change frozen 'backing' link from 'hd0' to 'hd1'")
1046
1047        event = self.vm.event_wait(name='BLOCK_JOB_READY')
1048        self.assert_qmp(event, 'data/device', 'commit0')
1049        self.assert_qmp(event, 'data/type', 'commit')
1050        self.assert_qmp_absent(event, 'data/error')
1051
1052        self.vm.cmd('block-job-complete', device='commit0')
1053
1054        self.wait_until_completed(drive = 'commit0')
1055
1056    # Reopen the chain during a block-commit job (from hd1 to hd2)
1057    def test_block_commit_2(self):
1058        # hd2 <- hd1 <- hd0
1059        opts = hd_opts(0)
1060        opts['backing'] = hd_opts(1)
1061        opts['backing']['backing'] = hd_opts(2)
1062        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
1063
1064        self.vm.cmd('block-commit', conv_keys = True, job_id = 'commit0',
1065                    device = 'hd0', top_node = 'hd1',
1066                    auto_finalize = False)
1067
1068        # We can't remove hd2 while the commit job is ongoing
1069        opts['backing']['backing'] = None
1070        self.reopen(opts, {}, "Cannot change the option 'backing.driver'")
1071
1072        # We can't remove hd1 while the commit job is ongoing
1073        opts['backing'] = None
1074        self.reopen(opts, {}, "Cannot replace implicit backing child of hd0")
1075
1076        # hd2 <- hd0
1077        self.vm.run_job('commit0', auto_finalize = False, auto_dismiss = True)
1078
1079        self.assert_qmp(self.get_node('hd0'), 'ro', False)
1080        self.assertEqual(self.get_node('hd1'), None)
1081        self.assert_qmp(self.get_node('hd2'), 'ro', True)
1082
1083    def run_test_iothreads(self, iothread_a, iothread_b, errmsg = None,
1084                           opts_a = None, opts_b = None):
1085        opts = opts_a or hd_opts(0)
1086        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
1087
1088        opts2 = opts_b or hd_opts(2)
1089        self.vm.cmd('blockdev-add', conv_keys = False, **opts2)
1090
1091        self.vm.cmd('object-add', qom_type='iothread', id='iothread0')
1092
1093        self.vm.cmd('object-add', qom_type='iothread', id='iothread1')
1094
1095        self.vm.cmd('device_add', driver='virtio-scsi', id='scsi0',
1096                    iothread=iothread_a)
1097
1098        self.vm.cmd('device_add', driver='virtio-scsi', id='scsi1',
1099                    iothread=iothread_b)
1100
1101        if iothread_a:
1102            self.vm.cmd('device_add', driver='scsi-hd', drive='hd0',
1103                        share_rw=True, bus="scsi0.0")
1104
1105        if iothread_b:
1106            self.vm.cmd('device_add', driver='scsi-hd', drive='hd2',
1107                        share_rw=True, bus="scsi1.0")
1108
1109        # Attaching the backing file may or may not work
1110        self.reopen(opts, {'backing': 'hd2'}, errmsg)
1111
1112        # But removing the backing file should always work
1113        self.reopen(opts, {'backing': None})
1114
1115        self.vm.shutdown()
1116
1117    # We don't allow setting a backing file that uses a different AioContext if
1118    # neither of them can switch to the other AioContext
1119    def test_iothreads_error(self):
1120        self.run_test_iothreads('iothread0', 'iothread1',
1121                                "Cannot change iothread of active block backend")
1122
1123    def test_iothreads_compatible_users(self):
1124        self.run_test_iothreads('iothread0', 'iothread0')
1125
1126    def test_iothreads_switch_backing(self):
1127        self.run_test_iothreads('iothread0', '')
1128
1129    def test_iothreads_switch_overlay(self):
1130        self.run_test_iothreads('', 'iothread0')
1131
1132    def test_iothreads_with_throttling(self):
1133        # Create a throttle-group object
1134        opts = { 'qom-type': 'throttle-group', 'id': 'group0',
1135                 'limits': { 'iops-total': 1000 } }
1136        self.vm.cmd('object-add', conv_keys = False, **opts)
1137
1138        # Options with a throttle filter between format and protocol
1139        opts = [
1140            {
1141                'driver': iotests.imgfmt,
1142                'node-name': f'hd{idx}',
1143                'file' : {
1144                    'node-name': f'hd{idx}-throttle',
1145                    'driver': 'throttle',
1146                    'throttle-group': 'group0',
1147                    'file': {
1148                        'driver': 'file',
1149                        'node-name': f'hd{idx}-file',
1150                        'filename': hd_path[idx],
1151                    },
1152                },
1153            }
1154            for idx in (0, 2)
1155        ]
1156
1157        self.run_test_iothreads('iothread0', 'iothread0', None,
1158                                opts[0], opts[1])
1159
1160if __name__ == '__main__':
1161    iotests.activate_logging()
1162    iotests.main(supported_fmts=["qcow2"],
1163                 supported_protocols=["file"])
1164