iotests: add dirty bitmap postcopy test

Test
- start two vms (vm_a, vm_b)

- in a
    - do writes from set A
    - do writes from set B
    - fix bitmap sha256
    - clear bitmap
    - do writes from set A
    - start migration
- than, in b
    - wait vm start (postcopy should start)
    - do writes from set B
    - check bitmap sha256

The test should verify postcopy migration and then merging with delta
(changes in target, during postcopy process).

Reduce supported cache modes to only 'none', because with cache on time
from source.STOP to target.RESUME is unpredictable and we can fail with
timout while waiting for target.RESUME.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-id: 20180313180320.339796-14-vsementsov@virtuozzo.com

tests/qemu-iotests/199

@@ -0,0 +1,118 @@
+#!/usr/bin/env python
+#
+# Tests for dirty bitmaps postcopy migration.
+#
+# Copyright (c) 2016-2017 Virtuozzo International GmbH. All rights reserved.
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+#
+
+import os
+import iotests
+import time
+from iotests import qemu_img
+
+disk_a = os.path.join(iotests.test_dir, 'disk_a')
+disk_b = os.path.join(iotests.test_dir, 'disk_b')
+size = '256G'
+fifo = os.path.join(iotests.test_dir, 'mig_fifo')
+
+class TestDirtyBitmapPostcopyMigration(iotests.QMPTestCase):
+
+    def tearDown(self):
+        self.vm_a.shutdown()
+        self.vm_b.shutdown()
+        os.remove(disk_a)
+        os.remove(disk_b)
+        os.remove(fifo)
+
+    def setUp(self):
+        os.mkfifo(fifo)
+        qemu_img('create', '-f', iotests.imgfmt, disk_a, size)
+        qemu_img('create', '-f', iotests.imgfmt, disk_b, size)
+        self.vm_a = iotests.VM(path_suffix='a').add_drive(disk_a)
+        self.vm_b = iotests.VM(path_suffix='b').add_drive(disk_b)
+        self.vm_b.add_incoming("exec: cat '" + fifo + "'")
+        self.vm_a.launch()
+        self.vm_b.launch()
+
+    def test_postcopy(self):
+        write_size = 0x40000000
+        granularity = 512
+        chunk = 4096
+
+        result = self.vm_a.qmp('block-dirty-bitmap-add', node='drive0',
+                               name='bitmap', granularity=granularity)
+        self.assert_qmp(result, 'return', {});
+
+        s = 0
+        while s < write_size:
+            self.vm_a.hmp_qemu_io('drive0', 'write %d %d' % (s, chunk))
+            s += 0x10000
+        s = 0x8000
+        while s < write_size:
+            self.vm_a.hmp_qemu_io('drive0', 'write %d %d' % (s, chunk))
+            s += 0x10000
+
+        result = self.vm_a.qmp('x-debug-block-dirty-bitmap-sha256',
+                               node='drive0', name='bitmap')
+        sha256 = result['return']['sha256']
+
+        result = self.vm_a.qmp('block-dirty-bitmap-clear', node='drive0',
+                               name='bitmap')
+        self.assert_qmp(result, 'return', {});
+        s = 0
+        while s < write_size:
+            self.vm_a.hmp_qemu_io('drive0', 'write %d %d' % (s, chunk))
+            s += 0x10000
+
+        bitmaps_cap = {'capability': 'dirty-bitmaps', 'state': True}
+        events_cap = {'capability': 'events', 'state': True}
+
+        result = self.vm_a.qmp('migrate-set-capabilities',
+                               capabilities=[bitmaps_cap, events_cap])
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm_b.qmp('migrate-set-capabilities',
+                               capabilities=[bitmaps_cap])
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm_a.qmp('migrate', uri='exec:cat>' + fifo)
+        self.assert_qmp(result, 'return', {})
+
+        result = self.vm_a.qmp('migrate-start-postcopy')
+        self.assert_qmp(result, 'return', {})
+
+        while True:
+            event = self.vm_a.event_wait('MIGRATION')
+            if event['data']['status'] == 'completed':
+                break
+
+        s = 0x8000
+        while s < write_size:
+            self.vm_b.hmp_qemu_io('drive0', 'write %d %d' % (s, chunk))
+            s += 0x10000
+
+        result = self.vm_b.qmp('query-block');
+        while len(result['return'][0]['dirty-bitmaps']) > 1:
+            time.sleep(2)
+            result = self.vm_b.qmp('query-block');
+
+        result = self.vm_b.qmp('x-debug-block-dirty-bitmap-sha256',
+                               node='drive0', name='bitmap')
+
+        self.assert_qmp(result, 'return/sha256', sha256);
+
+if __name__ == '__main__':
+    iotests.main(supported_fmts=['qcow2'], supported_cache_modes=['none'])