Merge remote-tracking branch 'remotes/maxreitz/tags/pull-block-2020-05-05' into staging

Block patches:
- Asynchronous copying for block-copy (i.e., the backup job)
- Allow resizing of qcow2 images when they have internal snapshots
- iotests: Logging improvements for Python tests
- iotest 153 fix, and block comment cleanups

# gpg: Signature made Tue 05 May 2020 13:56:58 BST
# gpg:                using RSA key 91BEB60A30DB3E8857D11829F407DB0061D5CF40
# gpg:                issuer "mreitz@redhat.com"
# gpg: Good signature from "Max Reitz <mreitz@redhat.com>" [full]
# Primary key fingerprint: 91BE B60A 30DB 3E88 57D1  1829 F407 DB00 61D5 CF40

* remotes/maxreitz/tags/pull-block-2020-05-05: (24 commits)
  block/block-copy: use aio-task-pool API
  block/block-copy: refactor task creation
  block/block-copy: add state pointer to BlockCopyTask
  block/block-copy: alloc task on each iteration
  block/block-copy: rename in-flight requests to tasks
  Fix iotest 153
  block: Comment cleanups
  qcow2: Tweak comment about bitmaps vs. resize
  qcow2: Allow resize of images with internal snapshots
  block: Add blk_new_with_bs() helper
  iotests: use python logging for iotests.log()
  iotests: Mark verify functions as private
  iotest 258: use script_main
  iotests: add script_initialize
  iotests: add hmp helper with logging
  iotests: limit line length to 79 chars
  iotests: touch up log function signature
  iotests: drop pre-Python 3.4 compatibility code
  iotests: alphabetize standard imports
  iotests: add pylintrc file
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

52 files changed, 412 insertions, 227 deletions

diff --git a/tests/qemu-iotests/001 b/tests/qemu-iotests/001
index d87a535c33..696726e45f 100755
--- a/tests/qemu-iotests/001
+++ b/tests/qemu-iotests/001
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 #
-# Test simple read/write using plain bdrv_read/bdrv_write
+# Test simple read/write using plain bdrv_pread/bdrv_pwrite
 #
 # Copyright (C) 2009 Red Hat, Inc.
 #
diff --git a/tests/qemu-iotests/030 b/tests/qemu-iotests/030
index aa911d266a..104e3cee1b 100755
--- a/tests/qemu-iotests/030
+++ b/tests/qemu-iotests/030
@@ -411,8 +411,8 @@ class TestParallelOps(iotests.QMPTestCase):
         result = self.vm.qmp('block-job-set-speed', device='drive0', speed=0)
         self.assert_qmp(result, 'return', {})
 
-        self.vm.run_job(job='drive0', auto_dismiss=True, use_log=False)
-        self.vm.run_job(job='node4', auto_dismiss=True, use_log=False)
+        self.vm.run_job(job='drive0', auto_dismiss=True)
+        self.vm.run_job(job='node4', auto_dismiss=True)
         self.assert_no_active_block_jobs()
 
     # Test a block-stream and a block-commit job in parallel
diff --git a/tests/qemu-iotests/052 b/tests/qemu-iotests/052
index 45a140910d..8d5c10601f 100755
--- a/tests/qemu-iotests/052
+++ b/tests/qemu-iotests/052
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 #
-# Test bdrv_read/bdrv_write using BDRV_O_SNAPSHOT
+# Test bdrv_pread/bdrv_pwrite using BDRV_O_SNAPSHOT
 #
 # Copyright (C) 2013 Red Hat, Inc.
 #
diff --git a/tests/qemu-iotests/055 b/tests/qemu-iotests/055
index 82b9f5f47d..4175fff5e4 100755
--- a/tests/qemu-iotests/055
+++ b/tests/qemu-iotests/055
@@ -469,7 +469,8 @@ class TestDriveCompression(iotests.QMPTestCase):
         qemu_img('create', '-f', fmt, blockdev_target_img,
                  str(TestDriveCompression.image_len), *args)
         if attach_target:
-            self.vm.add_drive(blockdev_target_img, format=fmt, interface="none")
+            self.vm.add_drive(blockdev_target_img,
+                              img_format=fmt, interface="none")
 
         self.vm.launch()
 
diff --git a/tests/qemu-iotests/061 b/tests/qemu-iotests/061
index ce285d3084..10eb243164 100755
--- a/tests/qemu-iotests/061
+++ b/tests/qemu-iotests/061
@@ -112,6 +112,41 @@ $QEMU_IO -c "read -P 0x2a 42M 64k" "$TEST_IMG" | _filter_qemu_io
 _check_test_img
 
 echo
+echo "=== Testing resize with snapshots ==="
+echo
+_make_test_img -o "compat=0.10" 32M
+$QEMU_IO -c "write -P 0x2a 24M 64k" "$TEST_IMG" | _filter_qemu_io
+$QEMU_IMG snapshot -c foo "$TEST_IMG"
+$QEMU_IMG resize "$TEST_IMG" 64M &&
+    echo "unexpected pass"
+$PYTHON qcow2.py "$TEST_IMG" dump-header | grep '^\(version\|size\|nb_snap\)'
+
+$QEMU_IMG amend -o "compat=1.1,size=128M" "$TEST_IMG" ||
+    echo "unexpected fail"
+$PYTHON qcow2.py "$TEST_IMG" dump-header | grep '^\(version\|size\|nb_snap\)'
+
+$QEMU_IMG snapshot -c bar "$TEST_IMG"
+$QEMU_IMG resize --shrink "$TEST_IMG" 64M ||
+    echo "unexpected fail"
+$PYTHON qcow2.py "$TEST_IMG" dump-header | grep '^\(version\|size\|nb_snap\)'
+
+$QEMU_IMG amend -o "compat=0.10,size=32M" "$TEST_IMG" &&
+    echo "unexpected pass"
+$PYTHON qcow2.py "$TEST_IMG" dump-header | grep '^\(version\|size\|nb_snap\)'
+
+$QEMU_IMG snapshot -a bar "$TEST_IMG" ||
+    echo "unexpected fail"
+$PYTHON qcow2.py "$TEST_IMG" dump-header | grep '^\(version\|size\|nb_snap\)'
+
+$QEMU_IMG snapshot -d bar "$TEST_IMG"
+$QEMU_IMG amend -o "compat=0.10,size=32M" "$TEST_IMG" ||
+    echo "unexpected fail"
+$PYTHON qcow2.py "$TEST_IMG" dump-header | grep '^\(version\|size\|nb_snap\)'
+
+_check_test_img
+
+
+echo
 echo "=== Testing dirty lazy_refcounts=off ==="
 echo
 _make_test_img -o "compat=1.1,lazy_refcounts=on" 64M
diff --git a/tests/qemu-iotests/061.out b/tests/qemu-iotests/061.out
index 413cc4e0f4..5a8d36d005 100644
--- a/tests/qemu-iotests/061.out
+++ b/tests/qemu-iotests/061.out
@@ -271,6 +271,34 @@ read 65536/65536 bytes at offset 44040192
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 No errors were found on the image.
 
+=== Testing resize with snapshots ===
+
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=33554432
+wrote 65536/65536 bytes at offset 25165824
+64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+qemu-img: Can't resize a v2 image which has snapshots
+version                   2
+size                      33554432
+nb_snapshots              1
+version                   3
+size                      134217728
+nb_snapshots              1
+Image resized.
+version                   3
+size                      67108864
+nb_snapshots              2
+qemu-img: Internal snapshots prevent downgrade of image
+version                   3
+size                      33554432
+nb_snapshots              2
+version                   3
+size                      134217728
+nb_snapshots              2
+version                   2
+size                      33554432
+nb_snapshots              1
+No errors were found on the image.
+
 === Testing dirty lazy_refcounts=off ===
 
 Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864
diff --git a/tests/qemu-iotests/134 b/tests/qemu-iotests/134
index 5f0fb86211..5162d21662 100755
--- a/tests/qemu-iotests/134
+++ b/tests/qemu-iotests/134
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 #
-# Test encrypted read/write using plain bdrv_read/bdrv_write
+# Test encrypted read/write using plain bdrv_pread/bdrv_pwrite
 #
 # Copyright (C) 2015 Red Hat, Inc.
 #
diff --git a/tests/qemu-iotests/149 b/tests/qemu-iotests/149
index b4a21bf7b7..852768f80a 100755
--- a/tests/qemu-iotests/149
+++ b/tests/qemu-iotests/149
@@ -382,8 +382,7 @@ def test_once(config, qemu_img=False):
 
 
 # Obviously we only work with the luks image format
-iotests.verify_image_format(supported_fmts=['luks'])
-iotests.verify_platform()
+iotests.script_initialize(supported_fmts=['luks'])
 
 # We need sudo in order to run cryptsetup to create
 # dm-crypt devices. This is safe to use on any
diff --git a/tests/qemu-iotests/153 b/tests/qemu-iotests/153
index 2b13111768..cf961d3609 100755
--- a/tests/qemu-iotests/153
+++ b/tests/qemu-iotests/153
@@ -122,7 +122,7 @@ for opts1 in "" "read-only=on" "read-only=on,force-share=on"; do
         _run_cmd $QEMU_IMG check       $L "${TEST_IMG}"
         _run_cmd $QEMU_IMG compare     $L "${TEST_IMG}" "${TEST_IMG}"
         _run_cmd $QEMU_IMG map         $L "${TEST_IMG}"
-        _run_cmd $QEMU_IMG amend -o "" $L "${TEST_IMG}"
+        _run_cmd $QEMU_IMG amend -o "size=$size" $L "${TEST_IMG}"
         _run_cmd $QEMU_IMG commit      $L "${TEST_IMG}"
         _run_cmd $QEMU_IMG resize      $L "${TEST_IMG}" $size
         _run_cmd $QEMU_IMG rebase      $L "${TEST_IMG}" -b "${TEST_IMG}.base"
diff --git a/tests/qemu-iotests/153.out b/tests/qemu-iotests/153.out
index f7464dd8d3..b2a90caa6b 100644
--- a/tests/qemu-iotests/153.out
+++ b/tests/qemu-iotests/153.out
@@ -56,7 +56,7 @@ _qemu_img_wrapper map TEST_DIR/t.qcow2
 qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get shared "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
-_qemu_img_wrapper amend -o  TEST_DIR/t.qcow2
+_qemu_img_wrapper amend -o size=32M TEST_DIR/t.qcow2
 qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
@@ -118,7 +118,7 @@ _qemu_img_wrapper compare -U TEST_DIR/t.qcow2 TEST_DIR/t.qcow2
 
 _qemu_img_wrapper map -U TEST_DIR/t.qcow2
 
-_qemu_img_wrapper amend -o  -U TEST_DIR/t.qcow2
+_qemu_img_wrapper amend -o size=32M -U TEST_DIR/t.qcow2
 qemu-img: unrecognized option '-U'
 Try 'qemu-img --help' for more information
 
@@ -187,7 +187,7 @@ _qemu_img_wrapper compare TEST_DIR/t.qcow2 TEST_DIR/t.qcow2
 
 _qemu_img_wrapper map TEST_DIR/t.qcow2
 
-_qemu_img_wrapper amend -o  TEST_DIR/t.qcow2
+_qemu_img_wrapper amend -o size=32M TEST_DIR/t.qcow2
 qemu-img: Could not open 'TEST_DIR/t.qcow2': Failed to get "write" lock
 Is another process using the image [TEST_DIR/t.qcow2]?
 
@@ -241,7 +241,7 @@ _qemu_img_wrapper compare -U TEST_DIR/t.qcow2 TEST_DIR/t.qcow2
 
 _qemu_img_wrapper map -U TEST_DIR/t.qcow2
 
-_qemu_img_wrapper amend -o  -U TEST_DIR/t.qcow2
+_qemu_img_wrapper amend -o size=32M -U TEST_DIR/t.qcow2
 qemu-img: unrecognized option '-U'
 Try 'qemu-img --help' for more information
 
@@ -303,7 +303,7 @@ _qemu_img_wrapper compare TEST_DIR/t.qcow2 TEST_DIR/t.qcow2
 
 _qemu_img_wrapper map TEST_DIR/t.qcow2
 
-_qemu_img_wrapper amend -o  TEST_DIR/t.qcow2
+_qemu_img_wrapper amend -o size=32M TEST_DIR/t.qcow2
 
 _qemu_img_wrapper commit TEST_DIR/t.qcow2
 
@@ -345,7 +345,7 @@ _qemu_img_wrapper compare -U TEST_DIR/t.qcow2 TEST_DIR/t.qcow2
 
 _qemu_img_wrapper map -U TEST_DIR/t.qcow2
 
-_qemu_img_wrapper amend -o  -U TEST_DIR/t.qcow2
+_qemu_img_wrapper amend -o size=32M -U TEST_DIR/t.qcow2
 qemu-img: unrecognized option '-U'
 Try 'qemu-img --help' for more information
 
diff --git a/tests/qemu-iotests/155 b/tests/qemu-iotests/155
index 571bce9de4..cb371d4649 100755
--- a/tests/qemu-iotests/155
+++ b/tests/qemu-iotests/155
@@ -188,7 +188,7 @@ class MirrorBaseClass(BaseClass):
 
         self.assert_qmp(result, 'return', {})
 
-        self.vm.run_job('mirror-job', use_log=False, auto_finalize=False,
+        self.vm.run_job('mirror-job', auto_finalize=False,
                         pre_finalize=self.openBacking, auto_dismiss=True)
 
     def testFull(self):
diff --git a/tests/qemu-iotests/188 b/tests/qemu-iotests/188
index afca44df54..09b9b6083a 100755
--- a/tests/qemu-iotests/188
+++ b/tests/qemu-iotests/188
@@ -1,6 +1,6 @@
 #!/usr/bin/env bash
 #
-# Test encrypted read/write using plain bdrv_read/bdrv_write
+# Test encrypted read/write using plain bdrv_pread/bdrv_pwrite
 #
 # Copyright (C) 2017 Red Hat, Inc.
 #
diff --git a/tests/qemu-iotests/194 b/tests/qemu-iotests/194
index 9dc1bd3510..8b1f720af4 100755
--- a/tests/qemu-iotests/194
+++ b/tests/qemu-iotests/194
@@ -21,8 +21,8 @@
 
 import iotests
 
-iotests.verify_image_format(supported_fmts=['qcow2', 'qed', 'raw'])
-iotests.verify_platform(['linux'])
+iotests.script_initialize(supported_fmts=['qcow2', 'qed', 'raw'],
+                          supported_platforms=['linux'])
 
 with iotests.FilePath('source.img') as source_img_path, \
      iotests.FilePath('dest.img') as dest_img_path, \
diff --git a/tests/qemu-iotests/202 b/tests/qemu-iotests/202
index 920a8683ef..e3900a44d1 100755
--- a/tests/qemu-iotests/202
+++ b/tests/qemu-iotests/202
@@ -24,8 +24,8 @@
 
 import iotests
 
-iotests.verify_image_format(supported_fmts=['qcow2'])
-iotests.verify_platform(['linux'])
+iotests.script_initialize(supported_fmts=['qcow2'],
+                          supported_platforms=['linux'])
 
 with iotests.FilePath('disk0.img') as disk0_img_path, \
      iotests.FilePath('disk1.img') as disk1_img_path, \
diff --git a/tests/qemu-iotests/203 b/tests/qemu-iotests/203
index 49eff5d405..4b4bd3307d 100755
--- a/tests/qemu-iotests/203
+++ b/tests/qemu-iotests/203
@@ -24,8 +24,8 @@
 
 import iotests
 
-iotests.verify_image_format(supported_fmts=['qcow2'])
-iotests.verify_platform(['linux'])
+iotests.script_initialize(supported_fmts=['qcow2'],
+                          supported_platforms=['linux'])
 
 with iotests.FilePath('disk0.img') as disk0_img_path, \
      iotests.FilePath('disk1.img') as disk1_img_path, \
diff --git a/tests/qemu-iotests/206 b/tests/qemu-iotests/206
index e2b50ae24d..f42432a838 100755
--- a/tests/qemu-iotests/206
+++ b/tests/qemu-iotests/206
@@ -23,7 +23,7 @@
 import iotests
 from iotests import imgfmt
 
-iotests.verify_image_format(supported_fmts=['qcow2'])
+iotests.script_initialize(supported_fmts=['qcow2'])
 
 with iotests.FilePath('t.qcow2') as disk_path, \
      iotests.FilePath('t.qcow2.base') as backing_path, \
diff --git a/tests/qemu-iotests/207 b/tests/qemu-iotests/207
index 3d9c1208ca..a6621410da 100755
--- a/tests/qemu-iotests/207
+++ b/tests/qemu-iotests/207
@@ -24,8 +24,10 @@ import iotests
 import subprocess
 import re
 
-iotests.verify_image_format(supported_fmts=['raw'])
-iotests.verify_protocol(supported=['ssh'])
+iotests.script_initialize(
+    supported_fmts=['raw'],
+    supported_protocols=['ssh'],
+)
 
 def filter_hash(qmsg):
     def _filter(key, value):
diff --git a/tests/qemu-iotests/208 b/tests/qemu-iotests/208
index 1c3fc8c7fd..6cb642f821 100755
--- a/tests/qemu-iotests/208
+++ b/tests/qemu-iotests/208
@@ -22,7 +22,7 @@
 
 import iotests
 
-iotests.verify_image_format(supported_fmts=['generic'])
+iotests.script_initialize(supported_fmts=['generic'])
 
 with iotests.FilePath('disk.img') as disk_img_path, \
      iotests.FilePath('disk-snapshot.img') as disk_snapshot_img_path, \
diff --git a/tests/qemu-iotests/209 b/tests/qemu-iotests/209
index 65c1a1e70a..8c804f4a30 100755
--- a/tests/qemu-iotests/209
+++ b/tests/qemu-iotests/209
@@ -22,7 +22,7 @@ import iotests
 from iotests import qemu_img_create, qemu_io, qemu_img_verbose, qemu_nbd, \
                     file_path
 
-iotests.verify_image_format(supported_fmts=['qcow2'])
+iotests.script_initialize(supported_fmts=['qcow2'])
 
 disk = file_path('disk')
 nbd_sock = file_path('nbd-sock', base_dir=iotests.sock_dir)
diff --git a/tests/qemu-iotests/210 b/tests/qemu-iotests/210
index e49896e23d..7bf591f313 100755
--- a/tests/qemu-iotests/210
+++ b/tests/qemu-iotests/210
@@ -23,8 +23,10 @@
 import iotests
 from iotests import imgfmt
 
-iotests.verify_image_format(supported_fmts=['luks'])
-iotests.verify_protocol(supported=['file'])
+iotests.script_initialize(
+    supported_fmts=['luks'],
+    supported_protocols=['file'],
+)
 
 with iotests.FilePath('t.luks') as disk_path, \
      iotests.VM() as vm:
diff --git a/tests/qemu-iotests/211 b/tests/qemu-iotests/211
index 163994d559..4969edb00c 100755
--- a/tests/qemu-iotests/211
+++ b/tests/qemu-iotests/211
@@ -23,8 +23,10 @@
 import iotests
 from iotests import imgfmt
 
-iotests.verify_image_format(supported_fmts=['vdi'])
-iotests.verify_protocol(supported=['file'])
+iotests.script_initialize(
+    supported_fmts=['vdi'],
+    supported_protocols=['file'],
+)
 
 def blockdev_create(vm, options):
     error = vm.blockdev_create(options)
diff --git a/tests/qemu-iotests/212 b/tests/qemu-iotests/212
index 800f92dd84..45d08842bb 100755
--- a/tests/qemu-iotests/212
+++ b/tests/qemu-iotests/212
@@ -23,8 +23,10 @@
 import iotests
 from iotests import imgfmt
 
-iotests.verify_image_format(supported_fmts=['parallels'])
-iotests.verify_protocol(supported=['file'])
+iotests.script_initialize(
+    supported_fmts=['parallels'],
+    supported_protocols=['file'],
+)
 
 with iotests.FilePath('t.parallels') as disk_path, \
      iotests.VM() as vm:
diff --git a/tests/qemu-iotests/213 b/tests/qemu-iotests/213
index 1eee45276a..cf638eb927 100755
--- a/tests/qemu-iotests/213
+++ b/tests/qemu-iotests/213
@@ -23,8 +23,10 @@
 import iotests
 from iotests import imgfmt
 
-iotests.verify_image_format(supported_fmts=['vhdx'])
-iotests.verify_protocol(supported=['file'])
+iotests.script_initialize(
+    supported_fmts=['vhdx'],
+    supported_protocols=['file'],
+)
 
 with iotests.FilePath('t.vhdx') as disk_path, \
      iotests.VM() as vm:
diff --git a/tests/qemu-iotests/216 b/tests/qemu-iotests/216
index 372f042d3e..de11d85b5d 100755
--- a/tests/qemu-iotests/216
+++ b/tests/qemu-iotests/216
@@ -23,8 +23,8 @@ import iotests
 from iotests import log, qemu_img, qemu_io_silent
 
 # Need backing file support
-iotests.verify_image_format(supported_fmts=['qcow2', 'qcow', 'qed', 'vmdk'])
-iotests.verify_platform(['linux'])
+iotests.script_initialize(supported_fmts=['qcow2', 'qcow', 'qed', 'vmdk'],
+                          supported_platforms=['linux'])
 
 log('')
 log('=== Copy-on-read across nodes ===')
diff --git a/tests/qemu-iotests/218 b/tests/qemu-iotests/218
index 1325ba9eaa..5586870456 100755
--- a/tests/qemu-iotests/218
+++ b/tests/qemu-iotests/218
@@ -29,7 +29,7 @@
 import iotests
 from iotests import log, qemu_img, qemu_io_silent
 
-iotests.verify_image_format(supported_fmts=['qcow2', 'raw'])
+iotests.script_initialize(supported_fmts=['qcow2', 'raw'])
 
 
 # Launches the VM, adds two null-co nodes (source and target), and
diff --git a/tests/qemu-iotests/219 b/tests/qemu-iotests/219
index b8774770c4..db272c5249 100755
--- a/tests/qemu-iotests/219
+++ b/tests/qemu-iotests/219
@@ -21,7 +21,7 @@
 
 import iotests
 
-iotests.verify_image_format(supported_fmts=['qcow2'])
+iotests.script_initialize(supported_fmts=['qcow2'])
 
 img_size = 4 * 1024 * 1024
 
diff --git a/tests/qemu-iotests/222 b/tests/qemu-iotests/222
index bf1718e179..6602f6b4ba 100755
--- a/tests/qemu-iotests/222
+++ b/tests/qemu-iotests/222
@@ -24,9 +24,10 @@
 import iotests
 from iotests import log, qemu_img, qemu_io, qemu_io_silent
 
-iotests.verify_platform(['linux'])
-iotests.verify_image_format(supported_fmts=['qcow2', 'qcow', 'qed', 'vmdk',
-                                            'vhdx', 'raw'])
+iotests.script_initialize(
+    supported_fmts=['qcow2', 'qcow', 'qed', 'vmdk', 'vhdx', 'raw'],
+    supported_platforms=['linux'],
+)
 
 patterns = [("0x5d", "0",         "64k"),
             ("0xd5", "1M",        "64k"),
diff --git a/tests/qemu-iotests/224 b/tests/qemu-iotests/224
index e91fb26fd8..81ca1e4898 100755
--- a/tests/qemu-iotests/224
+++ b/tests/qemu-iotests/224
@@ -26,8 +26,8 @@ from iotests import log, qemu_img, qemu_io_silent, filter_qmp_testfiles, \
 import json
 
 # Need backing file support (for arbitrary backing formats)
-iotests.verify_image_format(supported_fmts=['qcow2', 'qcow', 'qed'])
-iotests.verify_platform(['linux'])
+iotests.script_initialize(supported_fmts=['qcow2', 'qcow', 'qed'],
+                          supported_platforms=['linux'])
 
 
 # There are two variations of this test:
diff --git a/tests/qemu-iotests/228 b/tests/qemu-iotests/228
index 64bc82ee23..da0900fb82 100755
--- a/tests/qemu-iotests/228
+++ b/tests/qemu-iotests/228
@@ -25,8 +25,10 @@ from iotests import log, qemu_img, filter_testfiles, filter_imgfmt, \
         filter_qmp_testfiles, filter_qmp_imgfmt
 
 # Need backing file and change-backing-file support
-iotests.verify_image_format(supported_fmts=['qcow2', 'qed'])
-iotests.verify_platform(['linux'])
+iotests.script_initialize(
+    supported_fmts=['qcow2', 'qed'],
+    supported_platforms=['linux'],
+)
 
 
 def log_node_info(node):
diff --git a/tests/qemu-iotests/234 b/tests/qemu-iotests/234
index 324c1549fd..73c899ddae 100755
--- a/tests/qemu-iotests/234
+++ b/tests/qemu-iotests/234
@@ -23,8 +23,8 @@
 import iotests
 import os
 
-iotests.verify_image_format(supported_fmts=['qcow2'])
-iotests.verify_platform(['linux'])
+iotests.script_initialize(supported_fmts=['qcow2'],
+                          supported_platforms=['linux'])
 
 with iotests.FilePath('img') as img_path, \
      iotests.FilePath('backing') as backing_path, \
diff --git a/tests/qemu-iotests/235 b/tests/qemu-iotests/235
index 760826128e..d1b10ac36b 100755
--- a/tests/qemu-iotests/235
+++ b/tests/qemu-iotests/235
@@ -27,6 +27,8 @@ sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..', 'python'))
 
 from qemu.machine import QEMUMachine
 
+iotests.script_initialize(supported_fmts=['qcow2'])
+
 # Note:
 # This test was added to check that mirror dead-lock was fixed (see previous
 # commit before this test addition).
@@ -40,8 +42,6 @@ from qemu.machine import QEMUMachine
 
 size = 1 * 1024 * 1024 * 1024
 
-iotests.verify_image_format(supported_fmts=['qcow2'])
-
 disk = file_path('disk')
 
 # prepare source image
diff --git a/tests/qemu-iotests/236 b/tests/qemu-iotests/236
index 8ce927a16c..6f5cee2444 100755
--- a/tests/qemu-iotests/236
+++ b/tests/qemu-iotests/236
@@ -22,7 +22,7 @@
 import iotests
 from iotests import log
 
-iotests.verify_image_format(supported_fmts=['generic'])
+iotests.script_initialize(supported_fmts=['generic'])
 size = 64 * 1024 * 1024
 granularity = 64 * 1024
 
diff --git a/tests/qemu-iotests/237 b/tests/qemu-iotests/237
index 50ba364a3e..5b21ad3509 100755
--- a/tests/qemu-iotests/237
+++ b/tests/qemu-iotests/237
@@ -24,7 +24,7 @@ import math
 import iotests
 from iotests import imgfmt
 
-iotests.verify_image_format(supported_fmts=['vmdk'])
+iotests.script_initialize(supported_fmts=['vmdk'])
 
 with iotests.FilePath('t.vmdk') as disk_path, \
      iotests.FilePath('t.vmdk.1') as extent1_path, \
diff --git a/tests/qemu-iotests/238 b/tests/qemu-iotests/238
index d4e060228c..b8fcf15a1f 100755
--- a/tests/qemu-iotests/238
+++ b/tests/qemu-iotests/238
@@ -23,6 +23,8 @@ import os
 import iotests
 from iotests import log
 
+iotests.script_initialize()
+
 virtio_scsi_device = iotests.get_virtio_scsi_device()
 
 vm = iotests.VM()
diff --git a/tests/qemu-iotests/242 b/tests/qemu-iotests/242
index 97617876bc..64f1bd95e4 100755
--- a/tests/qemu-iotests/242
+++ b/tests/qemu-iotests/242
@@ -24,7 +24,7 @@ import struct
 from iotests import qemu_img_create, qemu_io, qemu_img_pipe, \
     file_path, img_info_log, log, filter_qemu_io
 
-iotests.verify_image_format(supported_fmts=['qcow2'])
+iotests.script_initialize(supported_fmts=['qcow2'])
 
 disk = file_path('disk')
 chunk = 256 * 1024
diff --git a/tests/qemu-iotests/245 b/tests/qemu-iotests/245
index 1001275a44..4f5f0bb901 100755
--- a/tests/qemu-iotests/245
+++ b/tests/qemu-iotests/245
@@ -1027,5 +1027,6 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         self.run_test_iothreads(None, 'iothread0')
 
 if __name__ == '__main__':
+    iotests.activate_logging()
     iotests.main(supported_fmts=["qcow2"],
                  supported_protocols=["file"])
diff --git a/tests/qemu-iotests/245.out b/tests/qemu-iotests/245.out
index 682b93394d..4b33dcaf5c 100644
--- a/tests/qemu-iotests/245.out
+++ b/tests/qemu-iotests/245.out
@@ -1,8 +1,3 @@
-.....................
-----------------------------------------------------------------------
-Ran 21 tests
-
-OK
 {"execute": "job-finalize", "arguments": {"id": "commit0"}}
 {"return": {}}
 {"data": {"id": "commit0", "type": "commit"}, "event": "BLOCK_JOB_PENDING", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
@@ -15,3 +10,8 @@ OK
 {"return": {}}
 {"data": {"id": "stream0", "type": "stream"}, "event": "BLOCK_JOB_PENDING", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
 {"data": {"device": "stream0", "len": 3145728, "offset": 3145728, "speed": 0, "type": "stream"}, "event": "BLOCK_JOB_COMPLETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
+.....................
+----------------------------------------------------------------------
+Ran 21 tests
+
+OK
diff --git a/tests/qemu-iotests/246 b/tests/qemu-iotests/246
index 59a216a839..58a479cc1f 100755
--- a/tests/qemu-iotests/246
+++ b/tests/qemu-iotests/246
@@ -22,7 +22,7 @@
 import iotests
 from iotests import log
 
-iotests.verify_image_format(supported_fmts=['qcow2'])
+iotests.script_initialize(supported_fmts=['qcow2'])
 size = 64 * 1024 * 1024 * 1024
 gran_small = 32 * 1024
 gran_large = 128 * 1024
diff --git a/tests/qemu-iotests/248 b/tests/qemu-iotests/248
index 68c374692e..18ba03467e 100755
--- a/tests/qemu-iotests/248
+++ b/tests/qemu-iotests/248
@@ -21,7 +21,7 @@
 import iotests
 from iotests import qemu_img_create, qemu_io, file_path, filter_qmp_testfiles
 
-iotests.verify_image_format(supported_fmts=['qcow2'])
+iotests.script_initialize(supported_fmts=['qcow2'])
 
 source, target = file_path('source', 'target')
 size = 5 * 1024 * 1024
diff --git a/tests/qemu-iotests/254 b/tests/qemu-iotests/254
index ee66c986db..150e58be8e 100755
--- a/tests/qemu-iotests/254
+++ b/tests/qemu-iotests/254
@@ -21,7 +21,7 @@
 import iotests
 from iotests import qemu_img_create, file_path, log
 
-iotests.verify_image_format(supported_fmts=['qcow2'])
+iotests.script_initialize(supported_fmts=['qcow2'])
 
 disk, top = file_path('disk', 'top')
 size = 1024 * 1024
diff --git a/tests/qemu-iotests/255 b/tests/qemu-iotests/255
index 4a4818bafb..8f08f741da 100755
--- a/tests/qemu-iotests/255
+++ b/tests/qemu-iotests/255
@@ -23,7 +23,7 @@
 import iotests
 from iotests import imgfmt
 
-iotests.verify_image_format(supported_fmts=['qcow2'])
+iotests.script_initialize(supported_fmts=['qcow2'])
 
 iotests.log('Finishing a commit job with background reads')
 iotests.log('============================================')
diff --git a/tests/qemu-iotests/256 b/tests/qemu-iotests/256
index e34074c83e..db8d6f31cf 100755
--- a/tests/qemu-iotests/256
+++ b/tests/qemu-iotests/256
@@ -23,7 +23,7 @@ import os
 import iotests
 from iotests import log
 
-iotests.verify_image_format(supported_fmts=['qcow2'])
+iotests.script_initialize(supported_fmts=['qcow2'])
 size = 64 * 1024 * 1024
 
 with iotests.FilePath('img0') as img0_path, \
diff --git a/tests/qemu-iotests/258 b/tests/qemu-iotests/258
index 091755a45c..e305a1502f 100755
--- a/tests/qemu-iotests/258
+++ b/tests/qemu-iotests/258
@@ -23,11 +23,6 @@ import iotests
 from iotests import log, qemu_img, qemu_io_silent, \
         filter_qmp_testfiles, filter_qmp_imgfmt
 
-# Need backing file and change-backing-file support
-iotests.verify_image_format(supported_fmts=['qcow2', 'qed'])
-iotests.verify_platform(['linux'])
-
-
 # Returns a node for blockdev-add
 def node(node_name, path, backing=None, fmt=None, throttle=None):
     if fmt is None:
@@ -160,4 +155,7 @@ def main():
     test_concurrent_finish(False)
 
 if __name__ == '__main__':
-    main()
+    # Need backing file and change-backing-file support
+    iotests.script_main(main,
+                        supported_fmts=['qcow2', 'qed'],
+                        supported_platforms=['linux'])
diff --git a/tests/qemu-iotests/260 b/tests/qemu-iotests/260
index 30c0de380d..804a7addb9 100755
--- a/tests/qemu-iotests/260
+++ b/tests/qemu-iotests/260
@@ -21,7 +21,9 @@
 import iotests
 from iotests import qemu_img_create, file_path, log, filter_qmp_event
 
-iotests.verify_image_format(supported_fmts=['qcow2'])
+iotests.script_initialize(
+    supported_fmts=['qcow2']
+)
 
 base, top = file_path('base', 'top')
 size = 64 * 1024 * 3
diff --git a/tests/qemu-iotests/262 b/tests/qemu-iotests/262
index 8835dce7be..03af061f94 100755
--- a/tests/qemu-iotests/262
+++ b/tests/qemu-iotests/262
@@ -23,8 +23,8 @@
 import iotests
 import os
 
-iotests.verify_image_format(supported_fmts=['qcow2'])
-iotests.verify_platform(['linux'])
+iotests.script_initialize(supported_fmts=['qcow2'],
+                          supported_platforms=['linux'])
 
 with iotests.FilePath('img') as img_path, \
      iotests.FilePath('mig_fifo') as fifo, \
diff --git a/tests/qemu-iotests/264 b/tests/qemu-iotests/264
index 879123a343..304a7443d7 100755
--- a/tests/qemu-iotests/264
+++ b/tests/qemu-iotests/264
@@ -24,7 +24,9 @@ import iotests
 from iotests import qemu_img_create, qemu_io_silent_check, file_path, \
         qemu_nbd_popen, log
 
-iotests.verify_image_format(supported_fmts=['qcow2'])
+iotests.script_initialize(
+    supported_fmts=['qcow2'],
+)
 
 disk_a, disk_b, nbd_sock = file_path('disk_a', 'disk_b', 'nbd-sock')
 nbd_uri = 'nbd+unix:///?socket=' + nbd_sock
diff --git a/tests/qemu-iotests/274 b/tests/qemu-iotests/274
index e951f723b8..5d1bf34dff 100755
--- a/tests/qemu-iotests/274
+++ b/tests/qemu-iotests/274
@@ -21,8 +21,8 @@
 
 import iotests
 
-iotests.verify_image_format(supported_fmts=['qcow2'])
-iotests.verify_platform(['linux'])
+iotests.script_initialize(supported_fmts=['qcow2'],
+                          supported_platforms=['linux'])
 
 size_short = 1 * 1024 * 1024
 size_long = 2 * 1024 * 1024
diff --git a/tests/qemu-iotests/277 b/tests/qemu-iotests/277
index 04aa15a3d5..d34f87021f 100755
--- a/tests/qemu-iotests/277
+++ b/tests/qemu-iotests/277
@@ -23,6 +23,8 @@ import subprocess
 import iotests
 from iotests import file_path, log
 
+iotests.script_initialize()
+
 
 nbd_sock, conf_file = file_path('nbd-sock', 'nbd-fault-injector.conf')
 
diff --git a/tests/qemu-iotests/280 b/tests/qemu-iotests/280
index 69288fdd0e..f594bb9ed2 100755
--- a/tests/qemu-iotests/280
+++ b/tests/qemu-iotests/280
@@ -22,9 +22,11 @@
 import iotests
 import os
 
-iotests.verify_image_format(supported_fmts=['qcow2'])
-iotests.verify_protocol(supported=['file'])
-iotests.verify_platform(['linux'])
+iotests.script_initialize(
+    supported_fmts=['qcow2'],
+    supported_protocols=['file'],
+    supported_platforms=['linux'],
+)
 
 with iotests.FilePath('base') as base_path , \
      iotests.FilePath('top') as top_path, \
diff --git a/tests/qemu-iotests/283 b/tests/qemu-iotests/283
index 55b7cff953..e17b953333 100644
--- a/tests/qemu-iotests/283
+++ b/tests/qemu-iotests/283
@@ -21,7 +21,9 @@
 import iotests
 
 # The test is unrelated to formats, restrict it to qcow2 to avoid extra runs
-iotests.verify_image_format(supported_fmts=['qcow2'])
+iotests.script_initialize(
+    supported_fmts=['qcow2'],
+)
 
 size = 1024 * 1024
 
diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 5f8c263d59..6c0e781af7 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -16,26 +16,39 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 #
 
-import errno
+import atexit
+from collections import OrderedDict
+import faulthandler
+import io
+import json
+import logging
 import os
 import re
+import signal
+import struct
 import subprocess
-import string
-import unittest
 import sys
-import struct
-import json
-import signal
-import logging
-import atexit
-import io
-from collections import OrderedDict
-import faulthandler
+from typing import (Any, Callable, Dict, Iterable,
+                    List, Optional, Sequence, TypeVar)
+import unittest
 
+# pylint: disable=import-error, wrong-import-position
 sys.path.append(os.path.join(os.path.dirname(__file__), '..', '..', 'python'))
 from qemu import qtest
 
-assert sys.version_info >= (3,6)
+assert sys.version_info >= (3, 6)
+
+# Type Aliases
+QMPResponse = Dict[str, Any]
+
+
+# Use this logger for logging messages directly from the iotests module
+logger = logging.getLogger('qemu.iotests')
+logger.addHandler(logging.NullHandler())
+
+# Use this logger for messages that ought to be used for diff output.
+test_logger = logging.getLogger('qemu.iotests.diff_io')
+
 
 faulthandler.enable()
 
@@ -80,9 +93,11 @@ luks_default_key_secret_opt = 'key-secret=keysec0'
 def qemu_img(*args):
     '''Run qemu-img and return the exit code'''
     devnull = open('/dev/null', 'r+')
-    exitcode = subprocess.call(qemu_img_args + list(args), stdin=devnull, stdout=devnull)
+    exitcode = subprocess.call(qemu_img_args + list(args),
+                               stdin=devnull, stdout=devnull)
     if exitcode < 0:
-        sys.stderr.write('qemu-img received signal %i: %s\n' % (-exitcode, ' '.join(qemu_img_args + list(args))))
+        sys.stderr.write('qemu-img received signal %i: %s\n'
+                         % (-exitcode, ' '.join(qemu_img_args + list(args))))
     return exitcode
 
 def ordered_qmp(qmsg, conv_keys=True):
@@ -121,7 +136,8 @@ def qemu_img_verbose(*args):
     '''Run qemu-img without suppressing its output and return the exit code'''
     exitcode = subprocess.call(qemu_img_args + list(args))
     if exitcode < 0:
-        sys.stderr.write('qemu-img received signal %i: %s\n' % (-exitcode, ' '.join(qemu_img_args + list(args))))
+        sys.stderr.write('qemu-img received signal %i: %s\n'
+                         % (-exitcode, ' '.join(qemu_img_args + list(args))))
     return exitcode
 
 def qemu_img_pipe(*args):
@@ -132,7 +148,8 @@ def qemu_img_pipe(*args):
                             universal_newlines=True)
     exitcode = subp.wait()
     if exitcode < 0:
-        sys.stderr.write('qemu-img received signal %i: %s\n' % (-exitcode, ' '.join(qemu_img_args + list(args))))
+        sys.stderr.write('qemu-img received signal %i: %s\n'
+                         % (-exitcode, ' '.join(qemu_img_args + list(args))))
     return subp.communicate()[0]
 
 def qemu_img_log(*args):
@@ -140,12 +157,12 @@ def qemu_img_log(*args):
     log(result, filters=[filter_testfiles])
     return result
 
-def img_info_log(filename, filter_path=None, imgopts=False, extra_args=[]):
-    args = [ 'info' ]
+def img_info_log(filename, filter_path=None, imgopts=False, extra_args=()):
+    args = ['info']
     if imgopts:
         args.append('--image-opts')
     else:
-        args += [ '-f', imgfmt ]
+        args += ['-f', imgfmt]
     args += extra_args
     args.append(filename)
 
@@ -162,7 +179,8 @@ def qemu_io(*args):
                             universal_newlines=True)
     exitcode = subp.wait()
     if exitcode < 0:
-        sys.stderr.write('qemu-io received signal %i: %s\n' % (-exitcode, ' '.join(args)))
+        sys.stderr.write('qemu-io received signal %i: %s\n'
+                         % (-exitcode, ' '.join(args)))
     return subp.communicate()[0]
 
 def qemu_io_log(*args):
@@ -224,7 +242,7 @@ class QemuIoInteractive:
         # quit command is in close(), '\n' is added automatically
         assert '\n' not in cmd
         cmd = cmd.strip()
-        assert cmd != 'q' and cmd != 'quit'
+        assert cmd not in ('q', 'quit')
         self._p.stdin.write(cmd + '\n')
         self._p.stdin.flush()
         return self._read_output()
@@ -246,10 +264,8 @@ def qemu_nbd_early_pipe(*args):
         sys.stderr.write('qemu-nbd received signal %i: %s\n' %
                          (-exitcode,
                           ' '.join(qemu_nbd_args + ['--fork'] + list(args))))
-    if exitcode == 0:
-        return exitcode, ''
-    else:
-        return exitcode, subp.communicate()[0]
+
+    return exitcode, subp.communicate()[0] if exitcode else ''
 
 def qemu_nbd_popen(*args):
     '''Run qemu-nbd in daemon mode and return the parent's exit code'''
@@ -286,10 +302,13 @@ win32_re = re.compile(r"\r")
 def filter_win32(msg):
     return win32_re.sub("", msg)
 
-qemu_io_re = re.compile(r"[0-9]* ops; [0-9\/:. sec]* \([0-9\/.inf]* [EPTGMKiBbytes]*\/sec and [0-9\/.inf]* ops\/sec\)")
+qemu_io_re = re.compile(r"[0-9]* ops; [0-9\/:. sec]* "
+                        r"\([0-9\/.inf]* [EPTGMKiBbytes]*\/sec "
+                        r"and [0-9\/.inf]* ops\/sec\)")
 def filter_qemu_io(msg):
     msg = filter_win32(msg)
-    return qemu_io_re.sub("X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)", msg)
+    return qemu_io_re.sub("X ops; XX:XX:XX.X "
+                          "(XXX YYY/sec and XXX ops/sec)", msg)
 
 chown_re = re.compile(r"chown [0-9]+:[0-9]+")
 def filter_chown(msg):
@@ -313,7 +332,7 @@ def filter_qmp(qmsg, filter_fn):
         items = qmsg.items()
 
     for k, v in items:
-        if isinstance(v, list) or isinstance(v, dict):
+        if isinstance(v, (dict, list)):
             qmsg[k] = filter_qmp(v, filter_fn)
         else:
             qmsg[k] = filter_fn(k, v)
@@ -324,7 +343,7 @@ def filter_testfiles(msg):
     return msg.replace(prefix, 'TEST_DIR/PID-')
 
 def filter_qmp_testfiles(qmsg):
-    def _filter(key, value):
+    def _filter(_key, value):
         if is_str(value):
             return filter_testfiles(value)
         return value
@@ -342,7 +361,9 @@ def filter_img_info(output, filename):
         line = filter_testfiles(line)
         line = line.replace(imgfmt, 'IMGFMT')
         line = re.sub('iters: [0-9]+', 'iters: XXX', line)
-        line = re.sub('uuid: [-a-f0-9]+', 'uuid: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX', line)
+        line = re.sub('uuid: [-a-f0-9]+',
+                      'uuid: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX',
+                      line)
         line = re.sub('cid: [0-9]+', 'cid: XXXXXXXXXX', line)
         lines.append(line)
     return '\n'.join(lines)
@@ -351,36 +372,40 @@ def filter_imgfmt(msg):
     return msg.replace(imgfmt, 'IMGFMT')
 
 def filter_qmp_imgfmt(qmsg):
-    def _filter(key, value):
+    def _filter(_key, value):
         if is_str(value):
             return filter_imgfmt(value)
         return value
     return filter_qmp(qmsg, _filter)
 
-def log(msg, filters=[], indent=None):
-    '''Logs either a string message or a JSON serializable message (like QMP).
-    If indent is provided, JSON serializable messages are pretty-printed.'''
+
+Msg = TypeVar('Msg', Dict[str, Any], List[Any], str)
+
+def log(msg: Msg,
+        filters: Iterable[Callable[[Msg], Msg]] = (),
+        indent: Optional[int] = None) -> None:
+    """
+    Logs either a string message or a JSON serializable message (like QMP).
+    If indent is provided, JSON serializable messages are pretty-printed.
+    """
     for flt in filters:
         msg = flt(msg)
-    if isinstance(msg, dict) or isinstance(msg, list):
-        # Python < 3.4 needs to know not to add whitespace when pretty-printing:
-        separators = (', ', ': ') if indent is None else (',', ': ')
+    if isinstance(msg, (dict, list)):
         # Don't sort if it's already sorted
         do_sort = not isinstance(msg, OrderedDict)
-        print(json.dumps(msg, sort_keys=do_sort,
-                         indent=indent, separators=separators))
+        test_logger.info(json.dumps(msg, sort_keys=do_sort, indent=indent))
     else:
-        print(msg)
+        test_logger.info(msg)
 
 class Timeout:
-    def __init__(self, seconds, errmsg = "Timeout"):
+    def __init__(self, seconds, errmsg="Timeout"):
         self.seconds = seconds
         self.errmsg = errmsg
     def __enter__(self):
         signal.signal(signal.SIGALRM, self.timeout)
         signal.setitimer(signal.ITIMER_REAL, self.seconds)
         return self
-    def __exit__(self, type, value, traceback):
+    def __exit__(self, exc_type, value, traceback):
         signal.setitimer(signal.ITIMER_REAL, 0)
         return False
     def timeout(self, signum, frame):
@@ -389,7 +414,7 @@ class Timeout:
 def file_pattern(name):
     return "{0}-{1}".format(os.getpid(), name)
 
-class FilePaths(object):
+class FilePaths:
     """
     FilePaths is an auto-generated filename that cleans itself up.
 
@@ -490,21 +515,21 @@ class VM(qtest.QEMUQtestMachine):
         self._args.append(opts)
         return self
 
-    def add_drive(self, path, opts='', interface='virtio', format=imgfmt):
+    def add_drive(self, path, opts='', interface='virtio', img_format=imgfmt):
         '''Add a virtio-blk drive to the VM'''
         options = ['if=%s' % interface,
                    'id=drive%d' % self._num_drives]
 
         if path is not None:
             options.append('file=%s' % path)
-            options.append('format=%s' % format)
+            options.append('format=%s' % img_format)
             options.append('cache=%s' % cachemode)
             options.append('aio=%s' % aiomode)
 
         if opts:
             options.append(opts)
 
-        if format == 'luks' and 'key-secret' not in opts:
+        if img_format == 'luks' and 'key-secret' not in opts:
             # default luks support
             if luks_default_secret_object not in self._args:
                 self.add_object(luks_default_secret_object)
@@ -529,30 +554,37 @@ class VM(qtest.QEMUQtestMachine):
         self._args.append(addr)
         return self
 
-    def pause_drive(self, drive, event=None):
-        '''Pause drive r/w operations'''
+    def hmp(self, command_line: str, use_log: bool = False) -> QMPResponse:
+        cmd = 'human-monitor-command'
+        kwargs = {'command-line': command_line}
+        if use_log:
+            return self.qmp_log(cmd, **kwargs)
+        else:
+            return self.qmp(cmd, **kwargs)
+
+    def pause_drive(self, drive: str, event: Optional[str] = None) -> None:
+        """Pause drive r/w operations"""
         if not event:
             self.pause_drive(drive, "read_aio")
             self.pause_drive(drive, "write_aio")
             return
-        self.qmp('human-monitor-command',
-                    command_line='qemu-io %s "break %s bp_%s"' % (drive, event, drive))
+        self.hmp(f'qemu-io {drive} "break {event} bp_{drive}"')
 
-    def resume_drive(self, drive):
-        self.qmp('human-monitor-command',
-                    command_line='qemu-io %s "remove_break bp_%s"' % (drive, drive))
+    def resume_drive(self, drive: str) -> None:
+        """Resume drive r/w operations"""
+        self.hmp(f'qemu-io {drive} "remove_break bp_{drive}"')
 
-    def hmp_qemu_io(self, drive, cmd):
-        '''Write to a given drive using an HMP command'''
-        return self.qmp('human-monitor-command',
-                        command_line='qemu-io %s "%s"' % (drive, cmd))
+    def hmp_qemu_io(self, drive: str, cmd: str,
+                    use_log: bool = False) -> QMPResponse:
+        """Write to a given drive using an HMP command"""
+        return self.hmp(f'qemu-io {drive} "{cmd}"', use_log=use_log)
 
     def flatten_qmp_object(self, obj, output=None, basestr=''):
         if output is None:
             output = dict()
         if isinstance(obj, list):
-            for i in range(len(obj)):
-                self.flatten_qmp_object(obj[i], output, basestr + str(i) + '.')
+            for i, item in enumerate(obj):
+                self.flatten_qmp_object(item, output, basestr + str(i) + '.')
         elif isinstance(obj, dict):
             for key in obj:
                 self.flatten_qmp_object(obj[key], output, basestr + key + '.')
@@ -573,7 +605,7 @@ class VM(qtest.QEMUQtestMachine):
             result.append(filter_qmp_event(ev))
         return result
 
-    def qmp_log(self, cmd, filters=[], indent=None, **kwargs):
+    def qmp_log(self, cmd, filters=(), indent=None, **kwargs):
         full_cmd = OrderedDict((
             ("execute", cmd),
             ("arguments", ordered_qmp(kwargs))
@@ -585,7 +617,7 @@ class VM(qtest.QEMUQtestMachine):
 
     # Returns None on success, and an error string on failure
     def run_job(self, job, auto_finalize=True, auto_dismiss=False,
-                pre_finalize=None, cancel=False, use_log=True, wait=60.0):
+                pre_finalize=None, cancel=False, wait=60.0):
         """
         run_job moves a job from creation through to dismissal.
 
@@ -598,7 +630,6 @@ class VM(qtest.QEMUQtestMachine):
                              invoked prior to issuing job-finalize, if any.
         :param cancel: Bool. When true, cancels the job after the pre_finalize
                        callback.
-        :param use_log: Bool. When false, does not log QMP messages.
         :param wait: Float. Timeout value specifying how long to wait for any
                      event, in seconds. Defaults to 60.0.
         """
@@ -616,8 +647,7 @@ class VM(qtest.QEMUQtestMachine):
         while True:
             ev = filter_qmp_event(self.events_wait(events, timeout=wait))
             if ev['event'] != 'JOB_STATUS_CHANGE':
-                if use_log:
-                    log(ev)
+                log(ev)
                 continue
             status = ev['data']['status']
             if status == 'aborting':
@@ -625,29 +655,18 @@ class VM(qtest.QEMUQtestMachine):
                 for j in result['return']:
                     if j['id'] == job:
                         error = j['error']
-                        if use_log:
-                            log('Job failed: %s' % (j['error']))
+                        log('Job failed: %s' % (j['error']))
             elif status == 'ready':
-                if use_log:
-                    self.qmp_log('job-complete', id=job)
-                else:
-                    self.qmp('job-complete', id=job)
+                self.qmp_log('job-complete', id=job)
             elif status == 'pending' and not auto_finalize:
                 if pre_finalize:
                     pre_finalize()
-                if cancel and use_log:
+                if cancel:
                     self.qmp_log('job-cancel', id=job)
-                elif cancel:
-                    self.qmp('job-cancel', id=job)
-                elif use_log:
-                    self.qmp_log('job-finalize', id=job)
                 else:
-                    self.qmp('job-finalize', id=job)
+                    self.qmp_log('job-finalize', id=job)
             elif status == 'concluded' and not auto_dismiss:
-                if use_log:
-                    self.qmp_log('job-dismiss', id=job)
-                else:
-                    self.qmp('job-dismiss', id=job)
+                self.qmp_log('job-dismiss', id=job)
             elif status == 'null':
                 return error
 
@@ -710,9 +729,7 @@ class VM(qtest.QEMUQtestMachine):
 
         for bitmap in bitmaps[node_name]:
             if bitmap.get('name', '') == bitmap_name:
-                if recording is None:
-                    return bitmap
-                elif bitmap.get('recording') == recording:
+                if recording is None or bitmap.get('recording') == recording:
                     return bitmap
         return None
 
@@ -763,12 +780,13 @@ class VM(qtest.QEMUQtestMachine):
             assert node is not None, 'Cannot follow path %s%s' % (root, path)
 
             try:
-                node_id = next(edge['child'] for edge in graph['edges'] \
-                                             if edge['parent'] == node['id'] and
-                                                edge['name'] == child_name)
+                node_id = next(edge['child'] for edge in graph['edges']
+                               if (edge['parent'] == node['id'] and
+                                   edge['name'] == child_name))
+
+                node = next(node for node in graph['nodes']
+                            if node['id'] == node_id)
 
-                node = next(node for node in graph['nodes'] \
-                                 if node['id'] == node_id)
             except StopIteration:
                 node = None
 
@@ -786,6 +804,12 @@ index_re = re.compile(r'([^\[]+)\[([^\]]+)\]')
 class QMPTestCase(unittest.TestCase):
     '''Abstract base class for QMP test cases'''
 
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        # Many users of this class set a VM property we rely on heavily
+        # in the methods below.
+        self.vm = None
+
     def dictpath(self, d, path):
         '''Traverse a path in a nested dict'''
         for component in path.split('/'):
@@ -795,16 +819,18 @@ class QMPTestCase(unittest.TestCase):
                 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)))
+                self.fail(f'failed path traversal for "{path}" in "{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)))
+                    self.fail(f'path component "{component}" in "{path}" '
+                              f'is not a list in "{d}"')
                 try:
                     d = d[idx]
                 except IndexError:
-                    self.fail('invalid index "%s" in path "%s" in "%s"' % (idx, path, str(d)))
+                    self.fail(f'invalid index "{idx}" in path "{path}" '
+                              f'in "{d}"')
         return d
 
     def assert_qmp_absent(self, d, path):
@@ -831,7 +857,7 @@ class QMPTestCase(unittest.TestCase):
         else:
             self.assertEqual(result, value,
                              '"%s" is "%s", expected "%s"'
-                                 % (path, str(result), str(value)))
+                             % (path, str(result), str(value)))
 
     def assert_no_active_block_jobs(self):
         result = self.vm.qmp('query-block-jobs')
@@ -841,24 +867,27 @@ class QMPTestCase(unittest.TestCase):
         """Issue a query-named-block-nodes and assert node_name and/or
         file_name is present in the result"""
         def check_equal_or_none(a, b):
-            return a == None or b == None or a == b
+            return a is None or b is None or a == b
         assert node_name or file_name
         result = self.vm.qmp('query-named-block-nodes')
         for x in result["return"]:
             if check_equal_or_none(x.get("node-name"), node_name) and \
                     check_equal_or_none(x.get("file"), file_name):
                 return
-        self.assertTrue(False, "Cannot find %s %s in result:\n%s" % \
-                (node_name, file_name, result))
+        self.fail("Cannot find %s %s in result:\n%s" %
+                  (node_name, file_name, result))
 
     def assert_json_filename_equal(self, json_filename, reference):
         '''Asserts that the given filename is a json: filename and that its
            content is equal to the given reference object'''
         self.assertEqual(json_filename[:5], 'json:')
-        self.assertEqual(self.vm.flatten_qmp_object(json.loads(json_filename[5:])),
-                         self.vm.flatten_qmp_object(reference))
+        self.assertEqual(
+            self.vm.flatten_qmp_object(json.loads(json_filename[5:])),
+            self.vm.flatten_qmp_object(reference)
+        )
 
-    def cancel_and_wait(self, drive='drive0', force=False, resume=False, wait=60.0):
+    def cancel_and_wait(self, drive='drive0', force=False,
+                        resume=False, wait=60.0):
         '''Cancel a block job and wait for it to finish, returning the event'''
         result = self.vm.qmp('block-job-cancel', device=drive, force=force)
         self.assert_qmp(result, 'return', {})
@@ -882,8 +911,8 @@ class QMPTestCase(unittest.TestCase):
         self.assert_no_active_block_jobs()
         return result
 
-    def wait_until_completed(self, drive='drive0', check_offset=True, wait=60.0,
-                             error=None):
+    def wait_until_completed(self, drive='drive0', check_offset=True,
+                             wait=60.0, error=None):
         '''Wait for a block job to finish, returning the event'''
         while True:
             for event in self.vm.get_qmp_events(wait=wait):
@@ -898,13 +927,13 @@ class QMPTestCase(unittest.TestCase):
                         self.assert_qmp(event, 'data/error', error)
                     self.assert_no_active_block_jobs()
                     return event
-                elif event['event'] == 'JOB_STATUS_CHANGE':
+                if event['event'] == 'JOB_STATUS_CHANGE':
                     self.assert_qmp(event, 'data/id', drive)
 
     def wait_ready(self, drive='drive0'):
-        '''Wait until a block job BLOCK_JOB_READY event'''
-        f = {'data': {'type': 'mirror', 'device': drive } }
-        event = self.vm.event_wait(name='BLOCK_JOB_READY', match=f)
+        """Wait until a BLOCK_JOB_READY event, and return the event."""
+        f = {'data': {'type': 'mirror', 'device': drive}}
+        return self.vm.event_wait(name='BLOCK_JOB_READY', match=f)
 
     def wait_ready_and_cancel(self, drive='drive0'):
         self.wait_ready(drive=drive)
@@ -933,7 +962,7 @@ class QMPTestCase(unittest.TestCase):
                 for job in result['return']:
                     if job['device'] == job_id:
                         found = True
-                        if job['paused'] == True and job['busy'] == False:
+                        if job['paused'] and not job['busy']:
                             return job
                         break
                 assert found
@@ -957,7 +986,7 @@ def notrun(reason):
     seq = os.path.basename(sys.argv[0])
 
     open('%s/%s.notrun' % (output_dir, seq), 'w').write(reason + '\n')
-    print('%s not run: %s' % (seq, reason))
+    logger.warning("%s not run: %s", seq, reason)
     sys.exit(0)
 
 def case_notrun(reason):
@@ -972,7 +1001,8 @@ def case_notrun(reason):
     open('%s/%s.casenotrun' % (output_dir, seq), 'a').write(
         '    [case not run] ' + reason + '\n')
 
-def verify_image_format(supported_fmts=[], unsupported_fmts=[]):
+def _verify_image_format(supported_fmts: Sequence[str] = (),
+                         unsupported_fmts: Sequence[str] = ()) -> None:
     assert not (supported_fmts and unsupported_fmts)
 
     if 'generic' in supported_fmts and \
@@ -986,7 +1016,8 @@ def verify_image_format(supported_fmts=[], unsupported_fmts=[]):
     if not_sup or (imgfmt in unsupported_fmts):
         notrun('not suitable for this image format: %s' % imgfmt)
 
-def verify_protocol(supported=[], unsupported=[]):
+def _verify_protocol(supported: Sequence[str] = (),
+                     unsupported: Sequence[str] = ()) -> None:
     assert not (supported and unsupported)
 
     if 'generic' in supported:
@@ -996,20 +1027,20 @@ def verify_protocol(supported=[], unsupported=[]):
     if not_sup or (imgproto in unsupported):
         notrun('not suitable for this protocol: %s' % imgproto)
 
-def verify_platform(supported=None, unsupported=None):
-    if unsupported is not None:
-        if any((sys.platform.startswith(x) for x in unsupported)):
-            notrun('not suitable for this OS: %s' % sys.platform)
+def _verify_platform(supported: Sequence[str] = (),
+                     unsupported: Sequence[str] = ()) -> None:
+    if any((sys.platform.startswith(x) for x in unsupported)):
+        notrun('not suitable for this OS: %s' % sys.platform)
 
-    if supported is not None:
+    if supported:
         if not any((sys.platform.startswith(x) for x in supported)):
             notrun('not suitable for this OS: %s' % sys.platform)
 
-def verify_cache_mode(supported_cache_modes=[]):
+def _verify_cache_mode(supported_cache_modes: Sequence[str] = ()) -> None:
     if supported_cache_modes and (cachemode not in supported_cache_modes):
         notrun('not suitable for this cache mode: %s' % cachemode)
 
-def verify_aio_mode(supported_aio_modes=[]):
+def _verify_aio_mode(supported_aio_modes: Sequence[str] = ()):
     if supported_aio_modes and (aiomode not in supported_aio_modes):
         notrun('not suitable for this aio mode: %s' % aiomode)
 
@@ -1022,16 +1053,19 @@ def verify_quorum():
         notrun('quorum support missing')
 
 def qemu_pipe(*args):
-    '''Run qemu with an option to print something and exit (e.g. a help option),
-    and return its output'''
+    """
+    Run qemu with an option to print something and exit (e.g. a help option).
+
+    :return: QEMU's stdout output.
+    """
     args = [qemu_prog] + qemu_opts + list(args)
     subp = subprocess.Popen(args, stdout=subprocess.PIPE,
                             stderr=subprocess.STDOUT,
                             universal_newlines=True)
     exitcode = subp.wait()
     if exitcode < 0:
-        sys.stderr.write('qemu received signal %i: %s\n' % (-exitcode,
-                         ' '.join(args)))
+        sys.stderr.write('qemu received signal %i: %s\n' %
+                         (-exitcode, ' '.join(args)))
     return subp.communicate()[0]
 
 def supported_formats(read_only=False):
@@ -1049,7 +1083,7 @@ def supported_formats(read_only=False):
 
     return supported_formats.formats[read_only]
 
-def skip_if_unsupported(required_formats=[], read_only=False):
+def skip_if_unsupported(required_formats=(), read_only=False):
     '''Skip Test Decorator
        Runs the test if all the required formats are whitelisted'''
     def skip_test_decorator(func):
@@ -1061,8 +1095,9 @@ def skip_if_unsupported(required_formats=[], read_only=False):
 
             usf_list = list(set(fmts) - set(supported_formats(read_only)))
             if usf_list:
-                test_case.case_skip('{}: formats {} are not whitelisted'.format(
-                    test_case, usf_list))
+                msg = f'{test_case}: formats {usf_list} are not whitelisted'
+                test_case.case_skip(msg)
+                return None
             else:
                 return func(test_case, *args, **kwargs)
         return func_wrapper
@@ -1074,11 +1109,23 @@ def skip_if_user_is_root(func):
     def func_wrapper(*args, **kwargs):
         if os.getuid() == 0:
             case_notrun('{}: cannot be run as root'.format(args[0]))
+            return None
         else:
             return func(*args, **kwargs)
     return func_wrapper
 
-def execute_unittest(output, verbosity, debug):
+def execute_unittest(debug=False):
+    """Executes unittests within the calling module."""
+
+    verbosity = 2 if debug else 1
+
+    if debug:
+        output = sys.stdout
+    else:
+        # We need to filter out the time taken from the output so that
+        # qemu-iotest can reliably diff the results against master output.
+        output = io.StringIO()
+
     runner = unittest.TextTestRunner(stream=output, descriptions=True,
                                      verbosity=verbosity)
     try:
@@ -1086,6 +1133,8 @@ def execute_unittest(output, verbosity, debug):
         # exception
         unittest.main(testRunner=runner)
     finally:
+        # We need to filter out the time taken from the output so that
+        # qemu-iotest can reliably diff the results against master output.
         if not debug:
             out = output.getvalue()
             out = re.sub(r'Ran (\d+) tests? in [\d.]+s', r'Ran \1 tests', out)
@@ -1097,13 +1146,19 @@ def execute_unittest(output, verbosity, debug):
 
             sys.stderr.write(out)
 
-def execute_test(test_function=None,
-                 supported_fmts=[],
-                 supported_platforms=None,
-                 supported_cache_modes=[], supported_aio_modes={},
-                 unsupported_fmts=[], supported_protocols=[],
-                 unsupported_protocols=[]):
-    """Run either unittest or script-style tests."""
+def execute_setup_common(supported_fmts: Sequence[str] = (),
+                         supported_platforms: Sequence[str] = (),
+                         supported_cache_modes: Sequence[str] = (),
+                         supported_aio_modes: Sequence[str] = (),
+                         unsupported_fmts: Sequence[str] = (),
+                         supported_protocols: Sequence[str] = (),
+                         unsupported_protocols: Sequence[str] = ()) -> bool:
+    """
+    Perform necessary setup for either script-style or unittest-style tests.
+
+    :return: Bool; Whether or not debug mode has been requested via the CLI.
+    """
+    # Note: Python 3.6 and pylint do not like 'Collection' so use 'Sequence'.
 
     # We are using TEST_DIR and QEMU_DEFAULT_MACHINE as proxies to
     # indicate that we're not being run via "check". There may be
@@ -1113,34 +1168,51 @@ def execute_test(test_function=None,
         sys.stderr.write('Please run this test via the "check" script\n')
         sys.exit(os.EX_USAGE)
 
-    debug = '-d' in sys.argv
-    verbosity = 1
-    verify_image_format(supported_fmts, unsupported_fmts)
-    verify_protocol(supported_protocols, unsupported_protocols)
-    verify_platform(supported=supported_platforms)
-    verify_cache_mode(supported_cache_modes)
-    verify_aio_mode(supported_aio_modes)
+    _verify_image_format(supported_fmts, unsupported_fmts)
+    _verify_protocol(supported_protocols, unsupported_protocols)
+    _verify_platform(supported=supported_platforms)
+    _verify_cache_mode(supported_cache_modes)
+    _verify_aio_mode(supported_aio_modes)
 
+    debug = '-d' in sys.argv
     if debug:
-        output = sys.stdout
-        verbosity = 2
         sys.argv.remove('-d')
-    else:
-        # We need to filter out the time taken from the output so that
-        # qemu-iotest can reliably diff the results against master output.
-        output = io.StringIO()
-
     logging.basicConfig(level=(logging.DEBUG if debug else logging.WARN))
+    logger.debug("iotests debugging messages active")
+
+    return debug
+
+def execute_test(*args, test_function=None, **kwargs):
+    """Run either unittest or script-style tests."""
 
+    debug = execute_setup_common(*args, **kwargs)
     if not test_function:
-        execute_unittest(output, verbosity, debug)
+        execute_unittest(debug)
     else:
         test_function()
 
+def activate_logging():
+    """Activate iotests.log() output to stdout for script-style tests."""
+    handler = logging.StreamHandler(stream=sys.stdout)
+    formatter = logging.Formatter('%(message)s')
+    handler.setFormatter(formatter)
+    test_logger.addHandler(handler)
+    test_logger.setLevel(logging.INFO)
+    test_logger.propagate = False
+
+# This is called from script-style iotests without a single point of entry
+def script_initialize(*args, **kwargs):
+    """Initialize script-style tests without running any tests."""
+    activate_logging()
+    execute_setup_common(*args, **kwargs)
+
+# This is called from script-style iotests with a single point of entry
 def script_main(test_function, *args, **kwargs):
     """Run script-style tests outside of the unittest framework"""
-    execute_test(test_function, *args, **kwargs)
+    activate_logging()
+    execute_test(*args, test_function=test_function, **kwargs)
 
+# This is called from unittest style iotests
 def main(*args, **kwargs):
     """Run tests using the unittest framework"""
-    execute_test(None, *args, **kwargs)
+    execute_test(*args, **kwargs)
diff --git a/tests/qemu-iotests/pylintrc b/tests/qemu-iotests/pylintrc
new file mode 100644
index 0000000000..5481afe528
--- /dev/null
+++ b/tests/qemu-iotests/pylintrc
@@ -0,0 +1,26 @@
+[MESSAGES CONTROL]
+
+# Disable the message, report, category or checker with the given id(s). You
+# can either give multiple identifiers separated by comma (,) or put this
+# option multiple times (only on the command line, not in the configuration
+# file where it should appear only once). You can also use "--disable=all" to
+# disable everything first and then reenable specific checks. For example, if
+# you want to run only the similarities checker, you can use "--disable=all
+# --enable=similarities". If you want to run only the classes checker, but have
+# no Warning level messages displayed, use "--disable=all --enable=classes
+# --disable=W".
+disable=invalid-name,
+        no-else-return,
+        too-few-public-methods,
+        too-many-arguments,
+        too-many-branches,
+        too-many-lines,
+        too-many-locals,
+        too-many-public-methods,
+        # These are temporary, and should be removed:
+        missing-docstring,
+
+[FORMAT]
+
+# Maximum number of characters on a single line.
+max-line-length=79