26 files changed, 662 insertions, 56 deletions
diff --git a/tests/libqtest.c b/tests/libqtest.c
index 8ac0c02af4..546a875913 100644
--- a/tests/libqtest.c
+++ b/tests/libqtest.c
@@ -1038,6 +1038,25 @@ QDict *qmp(const char *fmt, ...)
     return response;
 }
 
+void qmp_assert_success(const char *fmt, ...)
+{
+    va_list ap;
+    QDict *response;
+
+    va_start(ap, fmt);
+    response = qtest_vqmp(global_qtest, fmt, ap);
+    va_end(ap);
+
+    g_assert(response);
+    if (!qdict_haskey(response, "return")) {
+        QString *s = qobject_to_json_pretty(QOBJECT(response));
+        g_test_message("%s", qstring_get_str(s));
+        qobject_unref(s);
+    }
+    g_assert(qdict_haskey(response, "return"));
+    qobject_unref(response);
+}
+
 char *hmp(const char *fmt, ...)
 {
     va_list ap;
diff --git a/tests/libqtest.h b/tests/libqtest.h
index a98ea15b7d..32d927755d 100644
--- a/tests/libqtest.h
+++ b/tests/libqtest.h
@@ -619,6 +619,17 @@ static inline void qtest_end(void)
 QDict *qmp(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
 
 /**
+ * qmp_assert_success:
+ * @fmt...: QMP message to send to qemu, formatted like
+ * qobject_from_jsonf_nofail().  See parse_escape() for what's
+ * supported after '%'.
+ *
+ * Sends a QMP message to QEMU and asserts that a 'return' key is present in
+ * the response.
+ */
+void qmp_assert_success(const char *fmt, ...) GCC_FMT_ATTR(1, 2);
+
+/*
  * qmp_eventwait:
  * @s: #event event to wait for.
  *
diff --git a/tests/perf/block/qcow2/convert-blockstatus b/tests/perf/block/qcow2/convert-blockstatus
new file mode 100755
index 0000000000..a1a3c1ef43
--- /dev/null
+++ b/tests/perf/block/qcow2/convert-blockstatus
@@ -0,0 +1,71 @@
+#!/bin/bash
+#
+# Test lseek influence on qcow2 block-status
+#
+# Block layer may recursively check block_status in file child of qcow2, if
+# qcow2 driver returned DATA. There are several test cases to check influence
+# of lseek on block_status performance. To see real difference run on tmpfs.
+#
+# Copyright (c) 2019 Virtuozzo International GmbH. All rights reserved.
+#
+# Tests originally written by Kevin Wolf
+#
+# 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/>.
+#
+
+if [ "$#" -lt 1 ]; then
+    echo "Usage: $0 SOURCE_FILE"
+    exit 1
+fi
+
+ROOT_DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )/../../../.." >/dev/null 2>&1 && pwd )"
+QEMU_IMG="$ROOT_DIR/qemu-img"
+QEMU_IO="$ROOT_DIR/qemu-io"
+
+size=1G
+src="$1"
+
+# test-case plain
+
+(
+$QEMU_IMG create -f qcow2 "$src" $size
+for i in $(seq 16384 -1 0); do
+    echo "write $((i * 65536)) 64k"
+done | $QEMU_IO "$src"
+) > /dev/null
+
+echo -n "plain: "
+/usr/bin/time -f %e $QEMU_IMG convert -n "$src" null-co://
+
+# test-case forward
+
+(
+$QEMU_IMG create -f qcow2 "$src" $size
+for i in $(seq 0 2 16384); do
+    echo "write $((i * 65536)) 64k"
+done | $QEMU_IO "$src"
+for i in $(seq 1 2 16384); do
+    echo "write $((i * 65536)) 64k"
+done | $QEMU_IO "$src"
+) > /dev/null
+
+echo -n "forward: "
+/usr/bin/time -f %e $QEMU_IMG convert -n "$src" null-co://
+
+# test-case prealloc
+
+$QEMU_IMG create -f qcow2 -o preallocation=metadata "$src" $size > /dev/null
+
+echo -n "prealloc: "
+/usr/bin/time -f %e $QEMU_IMG convert -n "$src" null-co://
diff --git a/tests/qemu-iotests/051 b/tests/qemu-iotests/051
index a3deb1fcad..200660f977 100755
--- a/tests/qemu-iotests/051
+++ b/tests/qemu-iotests/051
@@ -192,6 +192,30 @@ case "$QEMU_DEFAULT_MACHINE" in
 esac
 
 echo
+echo === Attach to node in non-default iothread ===
+echo
+
+case "$QEMU_DEFAULT_MACHINE" in
+    pc)
+        iothread="-drive file=$TEST_IMG,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on"
+
+        # Can't add a device in the main thread while virtio-scsi0 uses the node
+        run_qemu $iothread -device ide-hd,drive=disk,share-rw=on
+        run_qemu $iothread -device virtio-blk-pci,drive=disk,share-rw=on
+        run_qemu $iothread -device lsi53c895a,id=lsi0 -device scsi-hd,bus=lsi0.0,drive=disk,share-rw=on
+        run_qemu $iothread -device virtio-scsi,id=virtio-scsi1 -device scsi-hd,bus=virtio-scsi1.0,drive=disk,share-rw=on
+
+        # virtio-blk enables the iothread only when the driver initialises the
+        # device, so a second virtio-blk device can't be added even with the
+        # same iothread. virtio-scsi allows this.
+        run_qemu $iothread -device virtio-blk-pci,drive=disk,iohtread=iothread0,share-rw=on
+        run_qemu $iothread -device virtio-scsi,id=virtio-scsi1,iothread=thread0 -device scsi-hd,bus=virtio-scsi1.0,drive=disk,share-rw=on
+        ;;
+     *)
+        ;;
+esac
+
+echo
 echo === Read-only ===
 echo
 
diff --git a/tests/qemu-iotests/051.out b/tests/qemu-iotests/051.out
index 9f1cf22608..8993835b94 100644
--- a/tests/qemu-iotests/051.out
+++ b/tests/qemu-iotests/051.out
@@ -137,6 +137,9 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) QEMU_PROG: -drive if=virtio: Device needs media, but drive is empty
 
 
+=== Attach to node in non-default iothread ===
+
+
 === Read-only ===
 
 Testing: -drive file=TEST_DIR/t.qcow2,if=virtio,readonly=on
diff --git a/tests/qemu-iotests/051.pc.out b/tests/qemu-iotests/051.pc.out
index c4743cc31c..2d811c166c 100644
--- a/tests/qemu-iotests/051.pc.out
+++ b/tests/qemu-iotests/051.pc.out
@@ -173,6 +173,33 @@ QEMU X.Y.Z monitor - type 'help' for more information
 (qemu) QEMU_PROG: -device scsi-hd,drive=disk: Device needs media, but drive is empty
 
 
+=== Attach to node in non-default iothread ===
+
+Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on -device ide-hd,drive=disk,share-rw=on
+QEMU X.Y.Z monitor - type 'help' for more information
+(qemu) QEMU_PROG: -device ide-hd,drive=disk,share-rw=on: Cannot change iothread of active block backend
+
+Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on -device virtio-blk-pci,drive=disk,share-rw=on
+QEMU X.Y.Z monitor - type 'help' for more information
+(qemu) QEMU_PROG: -device virtio-blk-pci,drive=disk,share-rw=on: Cannot change iothread of active block backend
+
+Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on -device lsi53c895a,id=lsi0 -device scsi-hd,bus=lsi0.0,drive=disk,share-rw=on
+QEMU X.Y.Z monitor - type 'help' for more information
+(qemu) QEMU_PROG: -device scsi-hd,bus=lsi0.0,drive=disk,share-rw=on: HBA does not support iothreads
+
+Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on -device virtio-scsi,id=virtio-scsi1 -device scsi-hd,bus=virtio-scsi1.0,drive=disk,share-rw=on
+QEMU X.Y.Z monitor - type 'help' for more information
+(qemu) QEMU_PROG: -device scsi-hd,bus=virtio-scsi1.0,drive=disk,share-rw=on: Cannot change iothread of active block backend
+
+Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on -device virtio-blk-pci,drive=disk,iohtread=iothread0,share-rw=on
+QEMU X.Y.Z monitor - type 'help' for more information
+(qemu) QEMU_PROG: -device virtio-blk-pci,drive=disk,iohtread=iothread0,share-rw=on: Cannot change iothread of active block backend
+
+Testing: -drive file=TEST_DIR/t.qcow2,if=none,node-name=disk -object iothread,id=thread0 -device virtio-scsi,iothread=thread0,id=virtio-scsi0 -device scsi-hd,bus=virtio-scsi0.0,drive=disk,share-rw=on -device virtio-scsi,id=virtio-scsi1,iothread=thread0 -device scsi-hd,bus=virtio-scsi1.0,drive=disk,share-rw=on
+QEMU X.Y.Z monitor - type 'help' for more information
+(qemu) quit
+
+
 === Read-only ===
 
 Testing: -drive file=TEST_DIR/t.qcow2,if=floppy,readonly=on
diff --git a/tests/qemu-iotests/102 b/tests/qemu-iotests/102
index 749ff66b8a..b898df436f 100755
--- a/tests/qemu-iotests/102
+++ b/tests/qemu-iotests/102
@@ -55,7 +55,7 @@ $QEMU_IO -c 'write 0 64k' "$TEST_IMG" | _filter_qemu_io
 $QEMU_IMG resize -f raw --shrink "$TEST_IMG" $((5 * 64 * 1024))
 
 $QEMU_IO -c map "$TEST_IMG"
-$QEMU_IMG map "$TEST_IMG"
+$QEMU_IMG map "$TEST_IMG" | _filter_qemu_img_map
 
 echo
 echo '=== Testing map on an image file truncated outside of qemu ==='
diff --git a/tests/qemu-iotests/102.out b/tests/qemu-iotests/102.out
index 4401b08fee..cd2fdc7f96 100644
--- a/tests/qemu-iotests/102.out
+++ b/tests/qemu-iotests/102.out
@@ -7,7 +7,8 @@ wrote 65536/65536 bytes at offset 0
 64 KiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
 Image resized.
 64 KiB (0x10000) bytes     allocated at offset 0 bytes (0x0)
-Offset          Length          Mapped to       File
+Offset          Length          File
+0               0x10000         TEST_DIR/t.IMGFMT
 
 === Testing map on an image file truncated outside of qemu ===
 
diff --git a/tests/qemu-iotests/141.out b/tests/qemu-iotests/141.out
index 41c7291258..4d71d9dcae 100644
--- a/tests/qemu-iotests/141.out
+++ b/tests/qemu-iotests/141.out
@@ -42,9 +42,9 @@ Formatting 'TEST_DIR/o.IMGFMT', fmt=IMGFMT size=1048576 backing_file=TEST_DIR/t.
 {"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "created", "id": "job0"}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "running", "id": "job0"}}
+{"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "ready", "id": "job0"}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_READY", "data": {"device": "job0", "len": 0, "offset": 0, "speed": 0, "type": "commit"}}
-{"return": {}}
 {"error": {"class": "GenericError", "desc": "Node 'drv0' is busy: block device is in use by block job: commit"}}
 {"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "waiting", "id": "job0"}}
diff --git a/tests/qemu-iotests/144.out b/tests/qemu-iotests/144.out
index 55299201e4..a9a8216bea 100644
--- a/tests/qemu-iotests/144.out
+++ b/tests/qemu-iotests/144.out
@@ -14,10 +14,10 @@ Formatting 'TEST_DIR/tmp.qcow2', fmt=qcow2 size=536870912 backing_file=TEST_DIR/
 
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "created", "id": "virtio0"}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "running", "id": "virtio0"}}
+{"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "ready", "id": "virtio0"}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_READY", "data": {"device": "virtio0", "len": 0, "offset": 0, "speed": 0, "type": "commit"}}
 {"return": {}}
-{"return": {}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "waiting", "id": "virtio0"}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "JOB_STATUS_CHANGE", "data": {"status": "pending", "id": "virtio0"}}
 {"timestamp": {"seconds":  TIMESTAMP, "microseconds":  TIMESTAMP}, "event": "BLOCK_JOB_COMPLETED", "data": {"device": "virtio0", "len": 0, "offset": 0, "speed": 0, "type": "commit"}}
diff --git a/tests/qemu-iotests/240 b/tests/qemu-iotests/240
index b4cf95096d..5be6b9c0f7 100755
--- a/tests/qemu-iotests/240
+++ b/tests/qemu-iotests/240
@@ -27,6 +27,12 @@ echo "QA output created by $seq"
 
 status=1	# failure is the default!
 
+_cleanup()
+{
+    rm -f "$TEST_DIR/nbd"
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
 # get standard environment, filters and checks
 . ./common.rc
 . ./common.filter
@@ -122,6 +128,21 @@ run_qemu <<EOF
 { "execute": "quit"}
 EOF
 
+echo
+echo === Attach a SCSI disks using the same block device as a NBD server ===
+echo
+
+run_qemu <<EOF
+{ "execute": "qmp_capabilities" }
+{ "execute": "blockdev-add", "arguments": {"driver": "null-co", "node-name": "hd0", "read-only": true}}
+{ "execute": "nbd-server-start", "arguments": {"addr":{"type":"unix","data":{"path":"$TEST_DIR/nbd"}}}}
+{ "execute": "nbd-server-add", "arguments": {"device":"hd0"}}
+{ "execute": "object-add", "arguments": {"qom-type": "iothread", "id": "iothread0"}}
+{ "execute": "device_add", "arguments": {"id": "scsi0", "driver": "${virtio_scsi}", "iothread": "iothread0"}}
+{ "execute": "device_add", "arguments": {"id": "scsi-hd0", "driver": "scsi-hd", "drive": "hd0", "bus": "scsi0.0"}}
+{ "execute": "quit"}
+EOF
+
 # success, all done
 echo "*** done"
 rm -f $seq.full
diff --git a/tests/qemu-iotests/240.out b/tests/qemu-iotests/240.out
index d76392966c..d00df50297 100644
--- a/tests/qemu-iotests/240.out
+++ b/tests/qemu-iotests/240.out
@@ -43,7 +43,20 @@ QMP_VERSION
 {"return": {}}
 {"return": {}}
 {"return": {}}
-{"error": {"class": "GenericError", "desc": "Cannot attach a blockdev that is using a different iothread"}}
+{"error": {"class": "GenericError", "desc": "Cannot change iothread of active block backend"}}
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"return": {}}
+{"return": {}}
+
+=== Attach a SCSI disks using the same block device as a NBD server ===
+
+Testing:
+QMP_VERSION
+{"return": {}}
 {"return": {}}
 {"return": {}}
 {"return": {}}
diff --git a/tests/qemu-iotests/250 b/tests/qemu-iotests/250
new file mode 100755
index 0000000000..c9c0a84a5a
--- /dev/null
+++ b/tests/qemu-iotests/250
@@ -0,0 +1,78 @@
+#!/usr/bin/env bash
+#
+# Test big discard in qcow2 shrink
+#
+# Copyright (c) 2019 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/>.
+#
+
+# creator
+owner=vsementsov@virtuozzo.com
+
+seq=`basename $0`
+echo "QA output created by $seq"
+
+status=1	# failure is the default!
+
+_cleanup()
+{
+    _cleanup_test_img
+}
+trap "_cleanup; exit \$status" 0 1 2 3 15
+
+# get standard environment, filters and checks
+. ./common.rc
+. ./common.filter
+
+_supported_fmt qcow2
+_supported_proto file
+_supported_os Linux
+
+# This test checks that qcow2_process_discards does not truncate a discard
+# request > 2G.
+# To reproduce bug we need to overflow int by one sequential discard, so we
+# need size > 2G, bigger cluster size (as with default 64k we may have maximum
+# of 512M sequential data, corresponding to one L1 entry), and we need some
+# data of the beginning of the disk mapped to the end of file to prevent
+# bdrv_co_truncate(bs->file) call in qcow2_co_truncate(), which might succeed
+# anyway.
+
+disk_usage()
+{
+    du --block-size=1 $1 | awk '{print $1}'
+}
+
+size=2100M
+IMGOPTS="cluster_size=1M,preallocation=metadata"
+
+_make_test_img $size
+$QEMU_IO -c 'discard 0 10M' -c 'discard 2090M 10M' \
+         -c 'write 2090M 10M' -c 'write 0 10M' "$TEST_IMG" | _filter_qemu_io
+
+# Check that our trick with swapping first and last 10M chunks succeeded.
+# Otherwise test may pass even if bdrv_pdiscard() fails in
+# qcow2_process_discards()
+$QEMU_IMG map "$TEST_IMG" | _filter_testdir
+
+before=$(disk_usage "$TEST_IMG")
+$QEMU_IMG resize --shrink "$TEST_IMG" 5M
+after=$(disk_usage "$TEST_IMG")
+
+echo "Disk usage delta: $((before - after))"
+
+# success, all done
+echo "*** done"
+rm -f $seq.full
+status=0
diff --git a/tests/qemu-iotests/250.out b/tests/qemu-iotests/250.out
new file mode 100644
index 0000000000..f480fd273b
--- /dev/null
+++ b/tests/qemu-iotests/250.out
@@ -0,0 +1,16 @@
+QA output created by 250
+Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=2202009600 preallocation=metadata
+discard 10485760/10485760 bytes at offset 0
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+discard 10485760/10485760 bytes at offset 2191523840
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 10485760/10485760 bytes at offset 2191523840
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+wrote 10485760/10485760 bytes at offset 0
+10 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+Offset          Length          Mapped to       File
+0               0xa00000        0x82f00000      TEST_DIR/t.qcow2
+0x82a00000      0xa00000        0x500000        TEST_DIR/t.qcow2
+Image resized.
+Disk usage delta: 15728640
+*** done
diff --git a/tests/qemu-iotests/255 b/tests/qemu-iotests/255
new file mode 100755
index 0000000000..49433ec122
--- /dev/null
+++ b/tests/qemu-iotests/255
@@ -0,0 +1,135 @@
+#!/usr/bin/env python
+#
+# Test commit job graph modifications while requests are active
+#
+# Copyright (C) 2019 Red Hat, Inc.
+#
+# Creator/Owner: Kevin Wolf <kwolf@redhat.com>
+#
+# 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 iotests
+from iotests import imgfmt
+
+iotests.verify_image_format(supported_fmts=['qcow2'])
+
+def blockdev_create(vm, options):
+    result = vm.qmp_log('blockdev-create',
+                        filters=[iotests.filter_qmp_testfiles],
+                        job_id='job0', options=options)
+
+    if 'return' in result:
+        assert result['return'] == {}
+        vm.run_job('job0')
+    iotests.log("")
+
+iotests.log('Finishing a commit job with background reads')
+iotests.log('============================================')
+iotests.log('')
+
+with iotests.FilePath('t.qcow2') as disk_path, \
+     iotests.FilePath('t.qcow2.mid') as mid_path, \
+     iotests.FilePath('t.qcow2.base') as base_path, \
+     iotests.VM() as vm:
+
+    iotests.log("=== Create backing chain and start VM ===")
+    iotests.log("")
+
+    size = 128 * 1024 * 1024
+    size_str = str(size)
+
+    iotests.create_image(base_path, size)
+    iotests.qemu_img_log('create', '-f', iotests.imgfmt, mid_path, size_str)
+    iotests.qemu_img_log('create', '-f', iotests.imgfmt, disk_path, size_str)
+
+    # Create a backing chain like this:
+    # base <- [throttled: bps-read=4096] <- mid <- overlay
+
+    vm.add_object('throttle-group,x-bps-read=4096,id=throttle0')
+    vm.add_blockdev('file,filename=%s,node-name=base' % (base_path))
+    vm.add_blockdev('throttle,throttle-group=throttle0,file=base,node-name=throttled')
+    vm.add_blockdev('file,filename=%s,node-name=mid-file' % (mid_path))
+    vm.add_blockdev('qcow2,file=mid-file,node-name=mid,backing=throttled')
+    vm.add_drive_raw('if=none,id=overlay,driver=qcow2,file=%s,backing=mid' % (disk_path))
+
+    vm.launch()
+
+    iotests.log("=== Start background read requests ===")
+    iotests.log("")
+
+    def start_requests():
+        vm.hmp_qemu_io('overlay', 'aio_read 0 4k')
+        vm.hmp_qemu_io('overlay', 'aio_read 0 4k')
+
+    start_requests()
+
+    iotests.log("=== Run a commit job ===")
+    iotests.log("")
+
+    result = vm.qmp_log('block-commit', job_id='job0', auto_finalize=False,
+                        device='overlay', top_node='mid')
+
+    vm.run_job('job0', auto_finalize=False, pre_finalize=start_requests,
+                auto_dismiss=True)
+
+    vm.shutdown()
+
+iotests.log('')
+iotests.log('Closing the VM while a job is being cancelled')
+iotests.log('=============================================')
+iotests.log('')
+
+with iotests.FilePath('src.qcow2') as src_path, \
+     iotests.FilePath('dst.qcow2') as dst_path, \
+     iotests.VM() as vm:
+
+    iotests.log('=== Create images and start VM ===')
+    iotests.log('')
+
+    size = 128 * 1024 * 1024
+    size_str = str(size)
+
+    iotests.qemu_img_log('create', '-f', iotests.imgfmt, src_path, size_str)
+    iotests.qemu_img_log('create', '-f', iotests.imgfmt, dst_path, size_str)
+
+    iotests.log(iotests.qemu_io('-f', iotests.imgfmt, '-c', 'write 0 1M',
+                                src_path),
+                filters=[iotests.filter_test_dir, iotests.filter_qemu_io])
+
+    vm.add_object('throttle-group,x-bps-read=4096,id=throttle0')
+
+    vm.add_blockdev('file,node-name=src-file,filename=%s' % (src_path))
+    vm.add_blockdev('%s,node-name=src,file=src-file' % (iotests.imgfmt))
+
+    vm.add_blockdev('file,node-name=dst-file,filename=%s' % (dst_path))
+    vm.add_blockdev('%s,node-name=dst,file=dst-file' % (iotests.imgfmt))
+
+    vm.add_blockdev('throttle,node-name=src-throttled,' +
+                    'throttle-group=throttle0,file=src')
+
+    vm.add_device('virtio-blk,drive=src-throttled')
+
+    vm.launch()
+
+    iotests.log('=== Start a mirror job ===')
+    iotests.log('')
+
+    vm.qmp_log('blockdev-mirror', job_id='job0', device='src-throttled',
+                                  target='dst', sync='full')
+
+    vm.qmp_log('block-job-cancel', device='job0')
+    vm.qmp_log('quit')
+
+    vm.shutdown()
diff --git a/tests/qemu-iotests/255.out b/tests/qemu-iotests/255.out
new file mode 100644
index 0000000000..348909fdef
--- /dev/null
+++ b/tests/qemu-iotests/255.out
@@ -0,0 +1,40 @@
+Finishing a commit job with background reads
+============================================
+
+=== Create backing chain and start VM ===
+
+Formatting 'TEST_DIR/PID-t.qcow2.mid', fmt=qcow2 size=134217728 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+
+Formatting 'TEST_DIR/PID-t.qcow2', fmt=qcow2 size=134217728 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+
+=== Start background read requests ===
+
+=== Run a commit job ===
+
+{"execute": "block-commit", "arguments": {"auto-finalize": false, "device": "overlay", "job-id": "job0", "top-node": "mid"}}
+{"return": {}}
+{"execute": "job-finalize", "arguments": {"id": "job0"}}
+{"return": {}}
+{"data": {"id": "job0", "type": "commit"}, "event": "BLOCK_JOB_PENDING", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
+{"data": {"device": "job0", "len": 134217728, "offset": 134217728, "speed": 0, "type": "commit"}, "event": "BLOCK_JOB_COMPLETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
+
+Closing the VM while a job is being cancelled
+=============================================
+
+=== Create images and start VM ===
+
+Formatting 'TEST_DIR/PID-src.qcow2', fmt=qcow2 size=134217728 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+
+Formatting 'TEST_DIR/PID-dst.qcow2', fmt=qcow2 size=134217728 cluster_size=65536 lazy_refcounts=off refcount_bits=16
+
+wrote 1048576/1048576 bytes at offset 0
+1 MiB, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)
+
+=== Start a mirror job ===
+
+{"execute": "blockdev-mirror", "arguments": {"device": "src-throttled", "job-id": "job0", "sync": "full", "target": "dst"}}
+{"return": {}}
+{"execute": "block-job-cancel", "arguments": {"device": "job0"}}
+{"return": {}}
+{"execute": "quit", "arguments": {}}
+{"return": {}}
diff --git a/tests/qemu-iotests/check b/tests/qemu-iotests/check
index 95162c6cf9..44ebf24080 100755
--- a/tests/qemu-iotests/check
+++ b/tests/qemu-iotests/check
@@ -876,7 +876,6 @@ do
                     fi
                 else
                     mv $tmp.out $seq.out.bad
-                    $diff -w "$reference" "$PWD"/$seq.out.bad
                     status="fail"
                     results="output mismatch (see $seq.out.bad)"
                     printdiff=true
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index 859c4b5e9f..f3b6d601b2 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -262,6 +262,8 @@
 247 rw quick
 248 rw quick
 249 rw auto quick
+250 rw auto quick
 252 rw auto backing quick
 253 rw auto quick
 254 rw auto backing quick
+255 rw auto quick
diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 7bde380d96..6bcddd8870 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -126,6 +126,11 @@ def qemu_img_pipe(*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):
+    result = qemu_img_pipe(*args)
+    log(result, filters=[filter_testfiles])
+    return result
+
 def img_info_log(filename, filter_path=None, imgopts=False, extra_args=[]):
     args = [ 'info' ]
     if imgopts:
@@ -533,7 +538,8 @@ class VM(qtest.QEMUQtestMachine):
         return result
 
     # Returns None on success, and an error string on failure
-    def run_job(self, job, auto_finalize=True, auto_dismiss=False):
+    def run_job(self, job, auto_finalize=True, auto_dismiss=False,
+                pre_finalize=None):
         error = None
         while True:
             for ev in self.get_qmp_events_filtered(wait=True):
@@ -546,6 +552,8 @@ class VM(qtest.QEMUQtestMachine):
                                 error = j['error']
                                 log('Job failed: %s' % (j['error']))
                     elif status == 'pending' and not auto_finalize:
+                        if pre_finalize:
+                            pre_finalize()
                         self.qmp_log('job-finalize', id=job)
                     elif status == 'concluded' and not auto_dismiss:
                         self.qmp_log('job-dismiss', id=job)
diff --git a/tests/test-bdrv-drain.c b/tests/test-bdrv-drain.c
index 5534c2adf9..12e2ecf517 100644
--- a/tests/test-bdrv-drain.c
+++ b/tests/test-bdrv-drain.c
@@ -206,7 +206,7 @@ static void test_drv_cb_common(enum drain_type drain_type, bool recursive)
 
     QEMUIOVector qiov = QEMU_IOVEC_INIT_BUF(qiov, NULL, 0);
 
-    blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR,
                               &error_abort);
     s = bs->opaque;
@@ -290,7 +290,7 @@ static void test_quiesce_common(enum drain_type drain_type, bool recursive)
     BlockBackend *blk;
     BlockDriverState *bs, *backing;
 
-    blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR,
                               &error_abort);
     blk_insert_bs(blk, bs, &error_abort);
@@ -353,7 +353,7 @@ static void test_nested(void)
     BDRVTestState *s, *backing_s;
     enum drain_type outer, inner;
 
-    blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR,
                               &error_abort);
     s = bs->opaque;
@@ -402,13 +402,13 @@ static void test_multiparent(void)
     BlockDriverState *bs_a, *bs_b, *backing;
     BDRVTestState *a_s, *b_s, *backing_s;
 
-    blk_a = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk_a = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     bs_a = bdrv_new_open_driver(&bdrv_test, "test-node-a", BDRV_O_RDWR,
                                 &error_abort);
     a_s = bs_a->opaque;
     blk_insert_bs(blk_a, bs_a, &error_abort);
 
-    blk_b = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk_b = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     bs_b = bdrv_new_open_driver(&bdrv_test, "test-node-b", BDRV_O_RDWR,
                                 &error_abort);
     b_s = bs_b->opaque;
@@ -475,13 +475,13 @@ static void test_graph_change_drain_subtree(void)
     BlockDriverState *bs_a, *bs_b, *backing;
     BDRVTestState *a_s, *b_s, *backing_s;
 
-    blk_a = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk_a = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     bs_a = bdrv_new_open_driver(&bdrv_test, "test-node-a", BDRV_O_RDWR,
                                 &error_abort);
     a_s = bs_a->opaque;
     blk_insert_bs(blk_a, bs_a, &error_abort);
 
-    blk_b = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk_b = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     bs_b = bdrv_new_open_driver(&bdrv_test, "test-node-b", BDRV_O_RDWR,
                                 &error_abort);
     b_s = bs_b->opaque;
@@ -555,7 +555,7 @@ static void test_graph_change_drain_all(void)
     BDRVTestState *a_s, *b_s;
 
     /* Create node A with a BlockBackend */
-    blk_a = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk_a = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     bs_a = bdrv_new_open_driver(&bdrv_test, "test-node-a", BDRV_O_RDWR,
                                 &error_abort);
     a_s = bs_a->opaque;
@@ -571,7 +571,7 @@ static void test_graph_change_drain_all(void)
     g_assert_cmpint(a_s->drain_count, ==, 1);
 
     /* Create node B with a BlockBackend */
-    blk_b = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk_b = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     bs_b = bdrv_new_open_driver(&bdrv_test, "test-node-b", BDRV_O_RDWR,
                                 &error_abort);
     b_s = bs_b->opaque;
@@ -672,13 +672,13 @@ static void test_iothread_common(enum drain_type drain_type, int drain_thread)
         goto out;
     }
 
-    blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     bs = bdrv_new_open_driver(&bdrv_test, "test-node", BDRV_O_RDWR,
                               &error_abort);
     s = bs->opaque;
     blk_insert_bs(blk, bs, &error_abort);
 
-    blk_set_aio_context(blk, ctx_a);
+    blk_set_aio_context(blk, ctx_a, &error_abort);
     aio_context_acquire(ctx_a);
 
     s->bh_indirection_ctx = ctx_b;
@@ -742,7 +742,7 @@ static void test_iothread_common(enum drain_type drain_type, int drain_thread)
     }
 
     aio_context_acquire(ctx_a);
-    blk_set_aio_context(blk, qemu_get_aio_context());
+    blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort);
     aio_context_release(ctx_a);
 
     bdrv_unref(bs);
@@ -883,7 +883,7 @@ static void test_blockjob_common_drain_node(enum drain_type drain_type,
     bdrv_set_backing_hd(src, src_backing, &error_abort);
     bdrv_unref(src_backing);
 
-    blk_src = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk_src = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     blk_insert_bs(blk_src, src_overlay, &error_abort);
 
     switch (drain_node) {
@@ -903,15 +903,16 @@ static void test_blockjob_common_drain_node(enum drain_type drain_type,
     if (use_iothread) {
         iothread = iothread_new();
         ctx = iothread_get_aio_context(iothread);
-        blk_set_aio_context(blk_src, ctx);
+        blk_set_aio_context(blk_src, ctx, &error_abort);
     } else {
         ctx = qemu_get_aio_context();
     }
 
     target = bdrv_new_open_driver(&bdrv_test, "target", BDRV_O_RDWR,
                                   &error_abort);
-    blk_target = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk_target = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     blk_insert_bs(blk_target, target, &error_abort);
+    blk_set_allow_aio_context_change(blk_target, true);
 
     aio_context_acquire(ctx);
     tjob = block_job_create("job0", &test_job_driver, NULL, src,
@@ -972,7 +973,7 @@ static void test_blockjob_common_drain_node(enum drain_type drain_type,
     g_assert_false(job->job.paused);
     g_assert_true(job->job.busy); /* We're in qemu_co_sleep_ns() */
 
-    do_drain_begin(drain_type, target);
+    do_drain_begin_unlocked(drain_type, target);
 
     if (drain_type == BDRV_DRAIN_ALL) {
         /* bdrv_drain_all() drains both src and target */
@@ -983,7 +984,7 @@ static void test_blockjob_common_drain_node(enum drain_type drain_type,
     g_assert_true(job->job.paused);
     g_assert_false(job->job.busy); /* The job is paused */
 
-    do_drain_end(drain_type, target);
+    do_drain_end_unlocked(drain_type, target);
 
     if (use_iothread) {
         /* paused is reset in the I/O thread, wait for it */
@@ -1001,7 +1002,8 @@ static void test_blockjob_common_drain_node(enum drain_type drain_type,
     g_assert_cmpint(ret, ==, (result == TEST_JOB_SUCCESS ? 0 : -EIO));
 
     if (use_iothread) {
-        blk_set_aio_context(blk_src, qemu_get_aio_context());
+        blk_set_aio_context(blk_src, qemu_get_aio_context(), &error_abort);
+        assert(blk_get_aio_context(blk_target) == qemu_get_aio_context());
     }
     aio_context_release(ctx);
 
@@ -1205,7 +1207,7 @@ static void do_test_delete_by_drain(bool detach_instead_of_delete,
                         &error_abort);
     bdrv_attach_child(bs, null_bs, "null-child", &child_file, &error_abort);
 
-    blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     blk_insert_bs(blk, bs, &error_abort);
 
     /* Referenced by blk now */
@@ -1368,7 +1370,7 @@ static void test_detach_indirect(bool by_parent_cb)
     c = bdrv_new_open_driver(&bdrv_test, "c", BDRV_O_RDWR, &error_abort);
 
     /* blk is a BB for parent-a */
-    blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     blk_insert_bs(blk, parent_a, &error_abort);
     bdrv_unref(parent_a);
 
@@ -1460,7 +1462,7 @@ static void test_append_to_drained(void)
     BlockDriverState *base, *overlay;
     BDRVTestState *base_s, *overlay_s;
 
-    blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     base = bdrv_new_open_driver(&bdrv_test, "base", BDRV_O_RDWR, &error_abort);
     base_s = base->opaque;
     blk_insert_bs(blk, base, &error_abort);
@@ -1507,16 +1509,16 @@ static void test_set_aio_context(void)
                               &error_abort);
 
     bdrv_drained_begin(bs);
-    bdrv_set_aio_context(bs, ctx_a);
+    bdrv_try_set_aio_context(bs, ctx_a, &error_abort);
 
     aio_context_acquire(ctx_a);
     bdrv_drained_end(bs);
 
     bdrv_drained_begin(bs);
-    bdrv_set_aio_context(bs, ctx_b);
+    bdrv_try_set_aio_context(bs, ctx_b, &error_abort);
     aio_context_release(ctx_a);
     aio_context_acquire(ctx_b);
-    bdrv_set_aio_context(bs, qemu_get_aio_context());
+    bdrv_try_set_aio_context(bs, qemu_get_aio_context(), &error_abort);
     aio_context_release(ctx_b);
     bdrv_drained_end(bs);
 
diff --git a/tests/test-bdrv-graph-mod.c b/tests/test-bdrv-graph-mod.c
index 747c0bf8fc..cfeec36566 100644
--- a/tests/test-bdrv-graph-mod.c
+++ b/tests/test-bdrv-graph-mod.c
@@ -102,7 +102,8 @@ static void test_update_perm_tree(void)
 {
     Error *local_err = NULL;
 
-    BlockBackend *root = blk_new(BLK_PERM_WRITE | BLK_PERM_CONSISTENT_READ,
+    BlockBackend *root = blk_new(qemu_get_aio_context(),
+                                 BLK_PERM_WRITE | BLK_PERM_CONSISTENT_READ,
                                  BLK_PERM_ALL & ~BLK_PERM_WRITE);
     BlockDriverState *bs = no_perm_node("node");
     BlockDriverState *filter = pass_through_node("filter");
@@ -165,7 +166,7 @@ static void test_update_perm_tree(void)
  */
 static void test_should_update_child(void)
 {
-    BlockBackend *root = blk_new(0, BLK_PERM_ALL);
+    BlockBackend *root = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL);
     BlockDriverState *bs = no_perm_node("node");
     BlockDriverState *filter = no_perm_node("filter");
     BlockDriverState *target = no_perm_node("target");
diff --git a/tests/test-block-backend.c b/tests/test-block-backend.c
index fd59f02bd0..5b5d6845c0 100644
--- a/tests/test-block-backend.c
+++ b/tests/test-block-backend.c
@@ -37,7 +37,8 @@ static void test_drain_aio_error_flush_cb(void *opaque, int ret)
 
 static void test_drain_aio_error(void)
 {
-    BlockBackend *blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    BlockBackend *blk = blk_new(qemu_get_aio_context(),
+                                BLK_PERM_ALL, BLK_PERM_ALL);
     BlockAIOCB *acb;
     bool completed = false;
 
@@ -53,7 +54,8 @@ static void test_drain_aio_error(void)
 
 static void test_drain_all_aio_error(void)
 {
-    BlockBackend *blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    BlockBackend *blk = blk_new(qemu_get_aio_context(),
+                                BLK_PERM_ALL, BLK_PERM_ALL);
     BlockAIOCB *acb;
     bool completed = false;
 
diff --git a/tests/test-block-iothread.c b/tests/test-block-iothread.c
index 59f692892e..79d9cf8a57 100644
--- a/tests/test-block-iothread.c
+++ b/tests/test-block-iothread.c
@@ -336,20 +336,20 @@ static void test_sync_op(const void *opaque)
     BlockDriverState *bs;
     BdrvChild *c;
 
-    blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     bs = bdrv_new_open_driver(&bdrv_test, "base", BDRV_O_RDWR, &error_abort);
     bs->total_sectors = 65536 / BDRV_SECTOR_SIZE;
     blk_insert_bs(blk, bs, &error_abort);
     c = QLIST_FIRST(&bs->parents);
 
-    blk_set_aio_context(blk, ctx);
+    blk_set_aio_context(blk, ctx, &error_abort);
     aio_context_acquire(ctx);
     t->fn(c);
     if (t->blkfn) {
         t->blkfn(blk);
     }
     aio_context_release(ctx);
-    blk_set_aio_context(blk, qemu_get_aio_context());
+    blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort);
 
     bdrv_unref(bs);
     blk_unref(blk);
@@ -415,7 +415,7 @@ static void test_attach_blockjob(void)
     BlockDriverState *bs;
     TestBlockJob *tjob;
 
-    blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     bs = bdrv_new_open_driver(&bdrv_test, "base", BDRV_O_RDWR, &error_abort);
     blk_insert_bs(blk, bs, &error_abort);
 
@@ -428,7 +428,7 @@ static void test_attach_blockjob(void)
         aio_poll(qemu_get_aio_context(), false);
     }
 
-    blk_set_aio_context(blk, ctx);
+    blk_set_aio_context(blk, ctx, &error_abort);
 
     tjob->n = 0;
     while (tjob->n == 0) {
@@ -436,7 +436,7 @@ static void test_attach_blockjob(void)
     }
 
     aio_context_acquire(ctx);
-    blk_set_aio_context(blk, qemu_get_aio_context());
+    blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort);
     aio_context_release(ctx);
 
     tjob->n = 0;
@@ -444,7 +444,7 @@ static void test_attach_blockjob(void)
         aio_poll(qemu_get_aio_context(), false);
     }
 
-    blk_set_aio_context(blk, ctx);
+    blk_set_aio_context(blk, ctx, &error_abort);
 
     tjob->n = 0;
     while (tjob->n == 0) {
@@ -453,7 +453,7 @@ static void test_attach_blockjob(void)
 
     aio_context_acquire(ctx);
     job_complete_sync(&tjob->common.job, &error_abort);
-    blk_set_aio_context(blk, qemu_get_aio_context());
+    blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort);
     aio_context_release(ctx);
 
     bdrv_unref(bs);
@@ -481,7 +481,7 @@ static void test_propagate_basic(void)
     QDict *options;
 
     /* Create bs_a and its BlockBackend */
-    blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     bs_a = bdrv_new_open_driver(&bdrv_test, "bs_a", BDRV_O_RDWR, &error_abort);
     blk_insert_bs(blk, bs_a, &error_abort);
 
@@ -497,7 +497,7 @@ static void test_propagate_basic(void)
     bs_verify = bdrv_open(NULL, NULL, options, BDRV_O_RDWR, &error_abort);
 
     /* Switch the AioContext */
-    blk_set_aio_context(blk, ctx);
+    blk_set_aio_context(blk, ctx, &error_abort);
     g_assert(blk_get_aio_context(blk) == ctx);
     g_assert(bdrv_get_aio_context(bs_a) == ctx);
     g_assert(bdrv_get_aio_context(bs_verify) == ctx);
@@ -505,7 +505,7 @@ static void test_propagate_basic(void)
 
     /* Switch the AioContext back */
     ctx = qemu_get_aio_context();
-    blk_set_aio_context(blk, ctx);
+    blk_set_aio_context(blk, ctx, &error_abort);
     g_assert(blk_get_aio_context(blk) == ctx);
     g_assert(bdrv_get_aio_context(bs_a) == ctx);
     g_assert(bdrv_get_aio_context(bs_verify) == ctx);
@@ -561,11 +561,11 @@ static void test_propagate_diamond(void)
     qdict_put_str(options, "raw", "bs_c");
 
     bs_verify = bdrv_open(NULL, NULL, options, BDRV_O_RDWR, &error_abort);
-    blk = blk_new(BLK_PERM_ALL, BLK_PERM_ALL);
+    blk = blk_new(qemu_get_aio_context(), BLK_PERM_ALL, BLK_PERM_ALL);
     blk_insert_bs(blk, bs_verify, &error_abort);
 
     /* Switch the AioContext */
-    blk_set_aio_context(blk, ctx);
+    blk_set_aio_context(blk, ctx, &error_abort);
     g_assert(blk_get_aio_context(blk) == ctx);
     g_assert(bdrv_get_aio_context(bs_verify) == ctx);
     g_assert(bdrv_get_aio_context(bs_a) == ctx);
@@ -574,7 +574,7 @@ static void test_propagate_diamond(void)
 
     /* Switch the AioContext back */
     ctx = qemu_get_aio_context();
-    blk_set_aio_context(blk, ctx);
+    blk_set_aio_context(blk, ctx, &error_abort);
     g_assert(blk_get_aio_context(blk) == ctx);
     g_assert(bdrv_get_aio_context(bs_verify) == ctx);
     g_assert(bdrv_get_aio_context(bs_a) == ctx);
@@ -593,7 +593,7 @@ static void test_propagate_mirror(void)
     IOThread *iothread = iothread_new();
     AioContext *ctx = iothread_get_aio_context(iothread);
     AioContext *main_ctx = qemu_get_aio_context();
-    BlockDriverState *src, *target;
+    BlockDriverState *src, *target, *filter;
     BlockBackend *blk;
     Job *job;
     Error *local_err = NULL;
@@ -610,11 +610,13 @@ static void test_propagate_mirror(void)
                  false, "filter_node", MIRROR_COPY_MODE_BACKGROUND,
                  &error_abort);
     job = job_get("job0");
+    filter = bdrv_find_node("filter_node");
 
     /* Change the AioContext of src */
     bdrv_try_set_aio_context(src, ctx, &error_abort);
     g_assert(bdrv_get_aio_context(src) == ctx);
     g_assert(bdrv_get_aio_context(target) == ctx);
+    g_assert(bdrv_get_aio_context(filter) == ctx);
     g_assert(job->aio_context == ctx);
 
     /* Change the AioContext of target */
@@ -623,9 +625,10 @@ static void test_propagate_mirror(void)
     aio_context_release(ctx);
     g_assert(bdrv_get_aio_context(src) == main_ctx);
     g_assert(bdrv_get_aio_context(target) == main_ctx);
+    g_assert(bdrv_get_aio_context(filter) == main_ctx);
 
     /* With a BlockBackend on src, changing target must fail */
-    blk = blk_new(0, BLK_PERM_ALL);
+    blk = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL);
     blk_insert_bs(blk, src, &error_abort);
 
     bdrv_try_set_aio_context(target, ctx, &local_err);
@@ -635,6 +638,7 @@ static void test_propagate_mirror(void)
     g_assert(blk_get_aio_context(blk) == main_ctx);
     g_assert(bdrv_get_aio_context(src) == main_ctx);
     g_assert(bdrv_get_aio_context(target) == main_ctx);
+    g_assert(bdrv_get_aio_context(filter) == main_ctx);
 
     /* ...unless we explicitly allow it */
     aio_context_acquire(ctx);
@@ -645,11 +649,12 @@ static void test_propagate_mirror(void)
     g_assert(blk_get_aio_context(blk) == ctx);
     g_assert(bdrv_get_aio_context(src) == ctx);
     g_assert(bdrv_get_aio_context(target) == ctx);
+    g_assert(bdrv_get_aio_context(filter) == ctx);
 
     job_cancel_sync_all();
 
     aio_context_acquire(ctx);
-    blk_set_aio_context(blk, main_ctx);
+    blk_set_aio_context(blk, main_ctx, &error_abort);
     bdrv_try_set_aio_context(target, main_ctx, &error_abort);
     aio_context_release(ctx);
 
@@ -658,6 +663,69 @@ static void test_propagate_mirror(void)
     bdrv_unref(target);
 }
 
+static void test_attach_second_node(void)
+{
+    IOThread *iothread = iothread_new();
+    AioContext *ctx = iothread_get_aio_context(iothread);
+    AioContext *main_ctx = qemu_get_aio_context();
+    BlockBackend *blk;
+    BlockDriverState *bs, *filter;
+    QDict *options;
+
+    blk = blk_new(ctx, BLK_PERM_ALL, BLK_PERM_ALL);
+    bs = bdrv_new_open_driver(&bdrv_test, "base", BDRV_O_RDWR, &error_abort);
+    blk_insert_bs(blk, bs, &error_abort);
+
+    options = qdict_new();
+    qdict_put_str(options, "driver", "raw");
+    qdict_put_str(options, "file", "base");
+
+    filter = bdrv_open(NULL, NULL, options, BDRV_O_RDWR, &error_abort);
+    g_assert(blk_get_aio_context(blk) == ctx);
+    g_assert(bdrv_get_aio_context(bs) == ctx);
+    g_assert(bdrv_get_aio_context(filter) == ctx);
+
+    blk_set_aio_context(blk, main_ctx, &error_abort);
+    g_assert(blk_get_aio_context(blk) == main_ctx);
+    g_assert(bdrv_get_aio_context(bs) == main_ctx);
+    g_assert(bdrv_get_aio_context(filter) == main_ctx);
+
+    bdrv_unref(filter);
+    bdrv_unref(bs);
+    blk_unref(blk);
+}
+
+static void test_attach_preserve_blk_ctx(void)
+{
+    IOThread *iothread = iothread_new();
+    AioContext *ctx = iothread_get_aio_context(iothread);
+    BlockBackend *blk;
+    BlockDriverState *bs;
+
+    blk = blk_new(ctx, BLK_PERM_ALL, BLK_PERM_ALL);
+    bs = bdrv_new_open_driver(&bdrv_test, "base", BDRV_O_RDWR, &error_abort);
+    bs->total_sectors = 65536 / BDRV_SECTOR_SIZE;
+
+    /* Add node to BlockBackend that has an iothread context assigned */
+    blk_insert_bs(blk, bs, &error_abort);
+    g_assert(blk_get_aio_context(blk) == ctx);
+    g_assert(bdrv_get_aio_context(bs) == ctx);
+
+    /* Remove the node again */
+    blk_remove_bs(blk);
+    g_assert(blk_get_aio_context(blk) == ctx);
+    g_assert(bdrv_get_aio_context(bs) == qemu_get_aio_context());
+
+    /* Re-attach the node */
+    blk_insert_bs(blk, bs, &error_abort);
+    g_assert(blk_get_aio_context(blk) == ctx);
+    g_assert(bdrv_get_aio_context(bs) == ctx);
+
+    blk_set_aio_context(blk, qemu_get_aio_context(), &error_abort);
+    bdrv_unref(bs);
+    blk_unref(blk);
+}
+
 int main(int argc, char **argv)
 {
     int i;
@@ -673,6 +741,8 @@ int main(int argc, char **argv)
     }
 
     g_test_add_func("/attach/blockjob", test_attach_blockjob);
+    g_test_add_func("/attach/second_node", test_attach_second_node);
+    g_test_add_func("/attach/preserve_blk_ctx", test_attach_preserve_blk_ctx);
     g_test_add_func("/propagate/basic", test_propagate_basic);
     g_test_add_func("/propagate/diamond", test_propagate_diamond);
     g_test_add_func("/propagate/mirror", test_propagate_mirror);
diff --git a/tests/test-blockjob.c b/tests/test-blockjob.c
index 652d1e8359..8c91980c70 100644
--- a/tests/test-blockjob.c
+++ b/tests/test-blockjob.c
@@ -68,7 +68,7 @@ static BlockJob *do_test_id(BlockBackend *blk, const char *id,
 static BlockBackend *create_blk(const char *name)
 {
     /* No I/O is performed on this device */
-    BlockBackend *blk = blk_new(0, BLK_PERM_ALL);
+    BlockBackend *blk = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL);
     BlockDriverState *bs;
 
     bs = bdrv_open("null-co://", NULL, NULL, 0, &error_abort);
diff --git a/tests/test-throttle.c b/tests/test-throttle.c
index 948a42c991..5644cf95ca 100644
--- a/tests/test-throttle.c
+++ b/tests/test-throttle.c
@@ -675,9 +675,9 @@ static void test_groups(void)
     ThrottleGroupMember *tgm1, *tgm2, *tgm3;
 
     /* No actual I/O is performed on these devices */
-    blk1 = blk_new(0, BLK_PERM_ALL);
-    blk2 = blk_new(0, BLK_PERM_ALL);
-    blk3 = blk_new(0, BLK_PERM_ALL);
+    blk1 = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL);
+    blk2 = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL);
+    blk3 = blk_new(qemu_get_aio_context(), 0, BLK_PERM_ALL);
 
     blkp1 = blk_get_public(blk1);
     blkp2 = blk_get_public(blk2);
diff --git a/tests/virtio-scsi-test.c b/tests/virtio-scsi-test.c
index 162b31c88d..1e535cb178 100644
--- a/tests/virtio-scsi-test.c
+++ b/tests/virtio-scsi-test.c
@@ -188,6 +188,53 @@ static void test_unaligned_write_same(void *obj, void *data,
     qvirtio_scsi_pci_free(vs);
 }
 
+static void test_iothread_attach_node(void *obj, void *data,
+                                      QGuestAllocator *t_alloc)
+{
+    QVirtioSCSIPCI *scsi_pci = obj;
+    QVirtioSCSI *scsi = &scsi_pci->scsi;
+    QVirtioSCSIQueues *vs;
+    char tmp_path[] = "/tmp/qtest.XXXXXX";
+    int fd;
+    int ret;
+
+    uint8_t buf[512] = { 0 };
+    const uint8_t write_cdb[VIRTIO_SCSI_CDB_SIZE] = {
+        /* WRITE(10) to LBA 0, transfer length 1 */
+        0x2a, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00
+    };
+
+    alloc = t_alloc;
+    vs = qvirtio_scsi_init(scsi->vdev);
+
+    /* Create a temporary qcow2 overlay*/
+    fd = mkstemp(tmp_path);
+    g_assert(fd >= 0);
+    close(fd);
+
+    if (!have_qemu_img()) {
+        g_test_message("QTEST_QEMU_IMG not set or qemu-img missing; "
+                       "skipping snapshot test");
+        goto fail;
+    }
+
+    mkqcow2(tmp_path, 64);
+
+    /* Attach the overlay to the null0 node */
+    qmp_assert_success("{'execute': 'blockdev-add', 'arguments': {"
+                       "   'driver': 'qcow2', 'node-name': 'overlay',"
+                       "   'backing': 'null0', 'file': {"
+                       "     'driver': 'file', 'filename': %s}}}", tmp_path);
+
+    /* Send a request to see if the AioContext is still right */
+    ret = virtio_scsi_do_command(vs, write_cdb, NULL, 0, buf, 512, NULL);
+    g_assert_cmphex(ret, ==, 0);
+
+fail:
+    qvirtio_scsi_pci_free(vs);
+    unlink(tmp_path);
+}
+
 static void *virtio_scsi_hotplug_setup(GString *cmd_line, void *arg)
 {
     g_string_append(cmd_line,
@@ -204,6 +251,15 @@ static void *virtio_scsi_setup(GString *cmd_line, void *arg)
     return arg;
 }
 
+static void *virtio_scsi_setup_iothread(GString *cmd_line, void *arg)
+{
+    g_string_append(cmd_line,
+                    " -object iothread,id=thread0"
+                    " -blockdev driver=null-co,node-name=null0"
+                    " -device scsi-hd,drive=null0");
+    return arg;
+}
+
 static void register_virtio_scsi_test(void)
 {
     QOSGraphTestOptions opts = { };
@@ -214,6 +270,13 @@ static void register_virtio_scsi_test(void)
     opts.before = virtio_scsi_setup;
     qos_add_test("unaligned-write-same", "virtio-scsi",
                  test_unaligned_write_same, &opts);
+
+    opts.before = virtio_scsi_setup_iothread;
+    opts.edge = (QOSGraphEdgeOptions) {
+        .extra_device_opts = "iothread=thread0",
+    };
+    qos_add_test("iothread-attach-node", "virtio-scsi-pci",
+                 test_iothread_attach_node, &opts);
 }
 
 libqos_init(register_virtio_scsi_test);