[RFC 0/2] introduce QEMUMachind.cmd()

[RFC 0/2] introduce QEMUMachind.cmd()

[Vladimir Sementsov-Ogievskiy]

Hi all!

I always dreamed about getting rid of pattern

    result = self.vm.qmp(...)
    self.assert_qmp(result, 'return', {})

Here is a suggestion to switch to

    self.vm.cmd(...)

pattern instead.

I'm not sure we really want to update so many tests. May be just commit
patch 01, and use new interface for new code. On the other hand, old
code always used as an example to write the new one.

The series is based on John's python branch.

Vladimir Sementsov-Ogievskiy (2):
  python/machine.py: upgrade vm.command() method
  iotests: use vm.cmd() instead of vm.qmp() where appropriate

 python/qemu/machine/machine.py                |  16 +-
 tests/qemu-iotests/030                        | 168 +++----
 tests/qemu-iotests/040                        | 167 +++---
 tests/qemu-iotests/041                        | 474 ++++++++----------
 tests/qemu-iotests/045                        |  15 +-
 tests/qemu-iotests/055                        |  61 +--
 tests/qemu-iotests/056                        |  23 +-
 tests/qemu-iotests/093                        |  41 +-
 tests/qemu-iotests/118                        | 221 ++++----
 tests/qemu-iotests/124                        |  69 ++-
 tests/qemu-iotests/129                        |  13 +-
 tests/qemu-iotests/132                        |   5 +-
 tests/qemu-iotests/139                        |  43 +-
 tests/qemu-iotests/147                        |  30 +-
 tests/qemu-iotests/151                        |  40 +-
 tests/qemu-iotests/155                        |  53 +-
 tests/qemu-iotests/165                        |   7 +-
 tests/qemu-iotests/196                        |   3 +-
 tests/qemu-iotests/205                        |   6 +-
 tests/qemu-iotests/245                        | 245 ++++-----
 tests/qemu-iotests/256                        |  34 +-
 tests/qemu-iotests/257                        |  36 +-
 tests/qemu-iotests/264                        |  31 +-
 tests/qemu-iotests/281                        |  21 +-
 tests/qemu-iotests/295                        |  27 +-
 tests/qemu-iotests/296                        |  14 +-
 tests/qemu-iotests/298                        |  13 +-
 tests/qemu-iotests/300                        |  50 +-
 tests/qemu-iotests/iotests.py                 |   6 +-
 .../tests/migrate-bitmaps-postcopy-test       |  31 +-
 tests/qemu-iotests/tests/migrate-bitmaps-test |  37 +-
 .../qemu-iotests/tests/migrate-during-backup  |  40 +-
 .../qemu-iotests/tests/migration-permissions  |   9 +-
 tests/qemu-iotests/tests/mirror-top-perms     |  15 +-
 34 files changed, 821 insertions(+), 1243 deletions(-)

-- 
2.35.1

[PATCH 1/2] python/machine.py: upgrade vm.command() method

[Vladimir Sementsov-Ogievskiy]

The method is not popular, we prefer use vm.qmp() and then check
success by hand.. But that's not optimal. To simplify movement to
vm.command() support same interface improvements like in vm.qmp() and
rename to shorter vm.cmd().

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org>
---
 python/qemu/machine/machine.py | 16 ++++++++++++---
 tests/qemu-iotests/256         | 34 ++++++++++++++++----------------
 tests/qemu-iotests/257         | 36 +++++++++++++++++-----------------
 3 files changed, 48 insertions(+), 38 deletions(-)

diff --git a/python/qemu/machine/machine.py b/python/qemu/machine/machine.py
index 07ac5a710b..a3fb840b93 100644
--- a/python/qemu/machine/machine.py
+++ b/python/qemu/machine/machine.py
@@ -648,14 +648,24 @@ def qmp(self, cmd: str,
             self._quit_issued = True
         return ret
 
-    def command(self, cmd: str,
-                conv_keys: bool = True,
-                **args: Any) -> QMPReturnValue:
+    def cmd(self, cmd: str,
+            args_dict: Optional[Dict[str, object]] = None,
+            conv_keys: Optional[bool] = None,
+            **args: Any) -> QMPReturnValue:
         """
         Invoke a QMP command.
         On success return the response dict.
         On failure raise an exception.
         """
+        if args_dict is not None:
+            assert not args
+            assert conv_keys is None
+            args = args_dict
+            conv_keys = False
+
+        if conv_keys is None:
+            conv_keys = True
+
         qmp_args = self._qmp_args(conv_keys, args)
         ret = self._qmp.command(cmd, **qmp_args)
         if cmd == 'quit':
diff --git a/tests/qemu-iotests/256 b/tests/qemu-iotests/256
index 13666813bd..fffc8ef055 100755
--- a/tests/qemu-iotests/256
+++ b/tests/qemu-iotests/256
@@ -40,25 +40,25 @@ with iotests.FilePath('img0') as img0_path, \
     def create_target(filepath, name, size):
         basename = os.path.basename(filepath)
         nodename = "file_{}".format(basename)
-        log(vm.command('blockdev-create', job_id='job1',
-                       options={
-                           'driver': 'file',
-                           'filename': filepath,
-                           'size': 0,
-                       }))
+        log(vm.cmd('blockdev-create', job_id='job1',
+                   options={
+                       'driver': 'file',
+                       'filename': filepath,
+                       'size': 0,
+                   }))
         vm.run_job('job1')
-        log(vm.command('blockdev-add', driver='file',
-                       node_name=nodename, filename=filepath))
-        log(vm.command('blockdev-create', job_id='job2',
-                       options={
-                           'driver': iotests.imgfmt,
-                           'file': nodename,
-                           'size': size,
-                       }))
+        log(vm.cmd('blockdev-add', driver='file',
+                   node_name=nodename, filename=filepath))
+        log(vm.cmd('blockdev-create', job_id='job2',
+                   options={
+                       'driver': iotests.imgfmt,
+                       'file': nodename,
+                       'size': size,
+                   }))
         vm.run_job('job2')
-        log(vm.command('blockdev-add', driver=iotests.imgfmt,
-                       node_name=name,
-                       file=nodename))
+        log(vm.cmd('blockdev-add', driver=iotests.imgfmt,
+                   node_name=name,
+                   file=nodename))
 
     log('--- Preparing images & VM ---\n')
     vm.add_object('iothread,id=iothread0')
diff --git a/tests/qemu-iotests/257 b/tests/qemu-iotests/257
index e7e7a2317e..7d3720b8e5 100755
--- a/tests/qemu-iotests/257
+++ b/tests/qemu-iotests/257
@@ -160,26 +160,26 @@ class Drive:
         file_node_name = "file_{}".format(basename)
         vm = self.vm
 
-        log(vm.command('blockdev-create', job_id='bdc-file-job',
-                       options={
-                           'driver': 'file',
-                           'filename': self.path,
-                           'size': 0,
-                       }))
+        log(vm.cmd('blockdev-create', job_id='bdc-file-job',
+                   options={
+                       'driver': 'file',
+                       'filename': self.path,
+                       'size': 0,
+                   }))
         vm.run_job('bdc-file-job')
-        log(vm.command('blockdev-add', driver='file',
-                       node_name=file_node_name, filename=self.path))
-
-        log(vm.command('blockdev-create', job_id='bdc-fmt-job',
-                       options={
-                           'driver': fmt,
-                           'file': file_node_name,
-                           'size': size,
-                       }))
+        log(vm.cmd('blockdev-add', driver='file',
+                   node_name=file_node_name, filename=self.path))
+
+        log(vm.cmd('blockdev-create', job_id='bdc-fmt-job',
+                   options={
+                       'driver': fmt,
+                       'file': file_node_name,
+                       'size': size,
+                   }))
         vm.run_job('bdc-fmt-job')
-        log(vm.command('blockdev-add', driver=fmt,
-                       node_name=name,
-                       file=file_node_name))
+        log(vm.cmd('blockdev-add', driver=fmt,
+                   node_name=name,
+                   file=file_node_name))
         self.fmt = fmt
         self.size = size
         self.node = name
-- 
2.35.1

Re: [PATCH 1/2] python/machine.py: upgrade vm.command() method

[Daniel P. Berrangé]

On Fri, Apr 08, 2022 at 08:02:13PM +0300, Vladimir Sementsov-Ogievskiy wrote:
> The method is not popular, we prefer use vm.qmp() and then check
> success by hand.. But that's not optimal. To simplify movement to
> vm.command() support same interface improvements like in vm.qmp() and
> rename to shorter vm.cmd().
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org>
> ---
>  python/qemu/machine/machine.py | 16 ++++++++++++---
>  tests/qemu-iotests/256         | 34 ++++++++++++++++----------------
>  tests/qemu-iotests/257         | 36 +++++++++++++++++-----------------
>  3 files changed, 48 insertions(+), 38 deletions(-)
> 
> diff --git a/python/qemu/machine/machine.py b/python/qemu/machine/machine.py
> index 07ac5a710b..a3fb840b93 100644
> --- a/python/qemu/machine/machine.py
> +++ b/python/qemu/machine/machine.py
> @@ -648,14 +648,24 @@ def qmp(self, cmd: str,
>              self._quit_issued = True
>          return ret
>  
> -    def command(self, cmd: str,
> -                conv_keys: bool = True,
> -                **args: Any) -> QMPReturnValue:
> +    def cmd(self, cmd: str,

FYI, the original 'command' name matches semantics of 'command'
in the QEMUMonitorProtocol class.  The QEMUMonitorProtocol
class has a 'cmd' method that matches semantics of 'qmp' in
QEMUMachine.

I think it is desirable to have consistency between naming in
the two classes.

The current use of both 'cmd' and 'command' in QEMUMonitorProtocol
is horrible naming though. How is anyone supposed to remember which
name raises the exception and which doesn't ? Urgh.

I agree with your desire to simplify things, but if anything I would
suggest we change both QEMUMonitorProtocol and QEMUMachine to have a
convention more like python's subprocess module:

 - 'cmd' runs without error checking, just returning the
   reply data as is

 - 'check_cmd' calls 'cmd' but raises an exception on error.


With regards,
Daniel
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Re: [PATCH 1/2] python/machine.py: upgrade vm.command() method

[John Snow]

[-- Attachment #1: Type: text/plain, Size: 3662 bytes --]

On Tue, Apr 19, 2022, 12:42 PM Daniel P. Berrangé <berrange@redhat.com>
wrote:

> On Fri, Apr 08, 2022 at 08:02:13PM +0300, Vladimir Sementsov-Ogievskiy
> wrote:
> > The method is not popular, we prefer use vm.qmp() and then check
> > success by hand.. But that's not optimal. To simplify movement to
> > vm.command() support same interface improvements like in vm.qmp() and
> > rename to shorter vm.cmd().
> >
> > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org>
> > ---
> >  python/qemu/machine/machine.py | 16 ++++++++++++---
> >  tests/qemu-iotests/256         | 34 ++++++++++++++++----------------
> >  tests/qemu-iotests/257         | 36 +++++++++++++++++-----------------
> >  3 files changed, 48 insertions(+), 38 deletions(-)
> >
> > diff --git a/python/qemu/machine/machine.py
> b/python/qemu/machine/machine.py
> > index 07ac5a710b..a3fb840b93 100644
> > --- a/python/qemu/machine/machine.py
> > +++ b/python/qemu/machine/machine.py
> > @@ -648,14 +648,24 @@ def qmp(self, cmd: str,
> >              self._quit_issued = True
> >          return ret
> >
> > -    def command(self, cmd: str,
> > -                conv_keys: bool = True,
> > -                **args: Any) -> QMPReturnValue:
> > +    def cmd(self, cmd: str,
>
> FYI, the original 'command' name matches semantics of 'command'
> in the QEMUMonitorProtocol class.  The QEMUMonitorProtocol
> class has a 'cmd' method that matches semantics of 'qmp' in
> QEMUMachine.
>
> I think it is desirable to have consistency between naming in
> the two classes.
>

Broadly agree.


> The current use of both 'cmd' and 'command' in QEMUMonitorProtocol
> is horrible naming though. How is anyone supposed to remember which
> name raises the exception and which doesn't ? Urgh.
>

Also agree.


> I agree with your desire to simplify things, but if anything I would
> suggest we change both QEMUMonitorProtocol and QEMUMachine to have a
> convention more like python's subprocess module:
>
>  - 'cmd' runs without error checking, just returning the
>    reply data as is
>
>  - 'check_cmd' calls 'cmd' but raises an exception on error.
>

Not sure I'm on board here, though.

For what it's worth, in async qmp I added a single method "execute()",
mimicking the name of the field used over the wire. It uses semantics like
command() here, in that it raises an exception on error and returns only
the response data and not the entire QMP response.

I'm in favor of, broadly, an approach wherein the default behavior raises
an exception and the caller must opt-in to squelch it; either via
try-except or a check=False argument. It should be a conscious decision.

(I realize this is not what the majority of iotests already does, but I
consider that a problem to fix and not a feature. See also my recent
efforts to make qemu_img() and qemu_io() raise a CalledProcessError by
default to improve failed test diagnostics and remove logical errors from
several iotests.)

Over time, I want to migrate machine.py off of the legacy.py interface and
onto the native async qmp. I believe using asyncio subprocess and asyncio
qmp will give better failure characteristics and better error readouts.

I've prototyped this a little, but it's a big project and there are still
pre-requisites to hit before I worry about it too much. Maybe this summer
I'll tackle it. Anyway, that's nobody else's problem right now, but I have
a predisposition to not want to steer far away from what the async api
provides. Just some roadmap info in case we need to collaborate better on
the future of this module.

--js

>

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Re: [PATCH 1/2] python/machine.py: upgrade vm.command() method

[Daniel P. Berrangé]

On Tue, Apr 19, 2022 at 01:08:06PM -0400, John Snow wrote:
> On Tue, Apr 19, 2022, 12:42 PM Daniel P. Berrangé <berrange@redhat.com>
> wrote:
> 
> > On Fri, Apr 08, 2022 at 08:02:13PM +0300, Vladimir Sementsov-Ogievskiy
> > wrote:
> > > The method is not popular, we prefer use vm.qmp() and then check
> > > success by hand.. But that's not optimal. To simplify movement to
> > > vm.command() support same interface improvements like in vm.qmp() and
> > > rename to shorter vm.cmd().
> > >
> > > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org>
> > > ---
> > >  python/qemu/machine/machine.py | 16 ++++++++++++---
> > >  tests/qemu-iotests/256         | 34 ++++++++++++++++----------------
> > >  tests/qemu-iotests/257         | 36 +++++++++++++++++-----------------
> > >  3 files changed, 48 insertions(+), 38 deletions(-)
> > >
> > > diff --git a/python/qemu/machine/machine.py
> > b/python/qemu/machine/machine.py
> > > index 07ac5a710b..a3fb840b93 100644
> > > --- a/python/qemu/machine/machine.py
> > > +++ b/python/qemu/machine/machine.py
> > > @@ -648,14 +648,24 @@ def qmp(self, cmd: str,
> > >              self._quit_issued = True
> > >          return ret
> > >
> > > -    def command(self, cmd: str,
> > > -                conv_keys: bool = True,
> > > -                **args: Any) -> QMPReturnValue:
> > > +    def cmd(self, cmd: str,
> >
> > FYI, the original 'command' name matches semantics of 'command'
> > in the QEMUMonitorProtocol class.  The QEMUMonitorProtocol
> > class has a 'cmd' method that matches semantics of 'qmp' in
> > QEMUMachine.
> >
> > I think it is desirable to have consistency between naming in
> > the two classes.
> >
> 
> Broadly agree.
> 
> 
> > The current use of both 'cmd' and 'command' in QEMUMonitorProtocol
> > is horrible naming though. How is anyone supposed to remember which
> > name raises the exception and which doesn't ? Urgh.
> >
> 
> Also agree.
> 
> 
> > I agree with your desire to simplify things, but if anything I would
> > suggest we change both QEMUMonitorProtocol and QEMUMachine to have a
> > convention more like python's subprocess module:
> >
> >  - 'cmd' runs without error checking, just returning the
> >    reply data as is
> >
> >  - 'check_cmd' calls 'cmd' but raises an exception on error.
> >
> 
> Not sure I'm on board here, though.
> 
> For what it's worth, in async qmp I added a single method "execute()",
> mimicking the name of the field used over the wire. It uses semantics like
> command() here, in that it raises an exception on error and returns only
> the response data and not the entire QMP response.
> 
> I'm in favor of, broadly, an approach wherein the default behavior raises
> an exception and the caller must opt-in to squelch it; either via
> try-except or a check=False argument. It should be a conscious decision.

I'd be happy with a single 'cmd' method with 'check=False' to turn
off exceptions on demand.

With regards,
Daniel
-- 
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Re: [PATCH 1/2] python/machine.py: upgrade vm.command() method

[Vladimir Sementsov-Ogievskiy]

On 4/8/22 20:02, Vladimir Sementsov-Ogievskiy wrote:
> The method is not popular, we prefer use vm.qmp() and then check

Suddenly I found, that I missed a lot of existing users: in scripts, in avocado tests.

Do you prefer to rename the method to "cmd()", and change all the occurrences, or keep longer "command()" name and update the second patch?


$ git grep '\.command('
docs/devel/testing.rst:          res = self.vm.command('human-monitor-command',
docs/devel/testing.rst:          first_res = first_machine.command(
docs/devel/testing.rst:          second_res = second_machine.command(
docs/devel/testing.rst:          third_res = self.get_vm(name='third_machine').command(
python/qemu/machine/machine.py:        ret = self._qmp.command(cmd, **qmp_args)
python/qemu/utils/qemu_ga_client.py:            return self.command('guest-' + name.replace('_', '-'), **kwds)
python/qemu/utils/qom.py:        rsp = self.qmp.command(
python/qemu/utils/qom.py:        rsp = self.qmp.command(
python/qemu/utils/qom.py:                rsp = self.qmp.command('qom-get', path=path,
python/qemu/utils/qom_common.py:        rsp = self.qmp.command('qom-list', path=path)
python/qemu/utils/qom_fuse.py:            data = str(self.qmp.command('qom-get', path=path, property=prop))
python/qemu/utils/qom_fuse.py:        return prefix + str(self.qmp.command('qom-get', path=path,
scripts/device-crash-test:    types = vm.command('qom-list-types', **kwargs)
scripts/device-crash-test:    devhelp = vm.command('human-monitor-command', **args)
scripts/device-crash-test:            self.machines = list(m['name'] for m in vm.command('query-machines'))
scripts/device-crash-test:            self.kvm_available = vm.command('query-kvm')['enabled']
scripts/render_block_graph.py:    bds_nodes = qmp.command('query-named-block-nodes')
scripts/render_block_graph.py:    job_nodes = qmp.command('query-block-jobs')
scripts/render_block_graph.py:    block_graph = qmp.command('x-debug-query-block-graph')
tests/avocado/avocado_qemu/__init__.py:        res = self.vm.command('human-monitor-command',
tests/avocado/cpu_queries.py:        cpus = self.vm.command('query-cpu-definitions')
tests/avocado/cpu_queries.py:            e = self.vm.command('query-cpu-model-expansion', model=model, type='full')
tests/avocado/hotplug_cpu.py:        self.vm.command('device_add',
tests/avocado/info_usernet.py:        res = self.vm.command('human-monitor-command',
tests/avocado/machine_arm_integratorcp.py:        self.vm.command('human-monitor-command', command_line='stop')
tests/avocado/machine_arm_integratorcp.py:        self.vm.command('human-monitor-command',
tests/avocado/machine_m68k_nextcube.py:        self.vm.command('human-monitor-command',
tests/avocado/machine_mips_malta.py:        self.vm.command('human-monitor-command', command_line='stop')
tests/avocado/machine_mips_malta.py:        self.vm.command('human-monitor-command',
tests/avocado/machine_s390_ccw_virtio.py:        self.vm.command('device_del', id='rn1')
tests/avocado/machine_s390_ccw_virtio.py:        self.vm.command('device_del', id='rn2')
tests/avocado/machine_s390_ccw_virtio.py:        self.vm.command('device_add', driver='virtio-net-ccw',
tests/avocado/machine_s390_ccw_virtio.py:        self.vm.command('device_del', id='net_4711')
tests/avocado/machine_s390_ccw_virtio.py:        self.vm.command('human-monitor-command', command_line='balloon 96')
tests/avocado/machine_s390_ccw_virtio.py:        self.vm.command('human-monitor-command', command_line='balloon 128')
tests/avocado/machine_s390_ccw_virtio.py:            self.vm.command('screendump', filename=ppmfile.name)
tests/avocado/machine_s390_ccw_virtio.py:        self.vm.command('object-add', qom_type='cryptodev-backend-builtin',
tests/avocado/machine_s390_ccw_virtio.py:        self.vm.command('device_add', driver='virtio-crypto-ccw', id='crypdev0',
tests/avocado/machine_s390_ccw_virtio.py:        self.vm.command('device_del', id='crypdev0')
tests/avocado/machine_s390_ccw_virtio.py:        self.vm.command('object-del', id='cbe0')
tests/avocado/migration.py:        return vm.command('query-migrate')['status'] in ('completed', 'failed')
tests/avocado/migration.py:        self.assertEqual(src_vm.command('query-migrate')['status'], 'completed')
tests/avocado/migration.py:        self.assertEqual(dst_vm.command('query-migrate')['status'], 'completed')
tests/avocado/migration.py:        self.assertEqual(dst_vm.command('query-status')['status'], 'running')
tests/avocado/migration.py:        self.assertEqual(src_vm.command('query-status')['status'],'postmigrate')
tests/avocado/pc_cpu_hotplug_props.py:        self.assertEquals(len(self.vm.command('query-cpus-fast')), 2)
tests/avocado/version.py:        res = self.vm.command('human-monitor-command',
tests/avocado/virtio_check_params.py:        output = vm.command('human-monitor-command',
tests/avocado/virtio_check_params.py:            machines = [m['name'] for m in vm.command('query-machines')]
tests/avocado/virtio_version.py:    return devtype in [d['name'] for d in vm.command('qom-list-types', implements=implements)]
tests/avocado/virtio_version.py:            pcibuses = vm.command('query-pci')
tests/avocado/x86_cpu_model_versions.py:        cpus = dict((m['name'], m) for m in self.vm.command('query-cpu-definitions'))
tests/avocado/x86_cpu_model_versions.py:        cpus = dict((m['name'], m) for m in self.vm.command('query-cpu-definitions'))
tests/avocado/x86_cpu_model_versions.py:        cpus = dict((m['name'], m) for m in self.vm.command('query-cpu-definitions'))
tests/avocado/x86_cpu_model_versions.py:        cpu_path = self.vm.command('query-cpus-fast')[0].get('qom-path')
tests/avocado/x86_cpu_model_versions.py:        return self.vm.command('qom-get', path=cpu_path, property=prop)
tests/docker/docker.py:        dkr.command(cmd="pull", quiet=args.quiet,
tests/docker/docker.py:        dkr.command(cmd="tag", quiet=args.quiet,
tests/docker/docker.py:        return Docker().command("images", argv, args.quiet)
tests/migration/guestperf/engine.py:        info = vm.command("query-migrate")
tests/migration/guestperf/engine.py:        vcpus = src.command("query-cpus-fast")
tests/migration/guestperf/engine.py:            resp = src.command("migrate-set-capabilities",
tests/migration/guestperf/engine.py:            resp = src.command("migrate-set-parameters",
tests/migration/guestperf/engine.py:            resp = src.command("migrate-set-capabilities",
tests/migration/guestperf/engine.py:            resp = dst.command("migrate-set-capabilities",
tests/migration/guestperf/engine.py:        resp = src.command("migrate-set-parameters",
tests/migration/guestperf/engine.py:        resp = src.command("migrate-set-parameters",
tests/migration/guestperf/engine.py:            resp = src.command("migrate-set-capabilities",
tests/migration/guestperf/engine.py:            resp = src.command("migrate-set-parameters",
tests/migration/guestperf/engine.py:            resp = dst.command("migrate-set-capabilities",
tests/migration/guestperf/engine.py:            resp = dst.command("migrate-set-parameters",
tests/migration/guestperf/engine.py:            resp = src.command("migrate-set-capabilities",
tests/migration/guestperf/engine.py:            resp = dst.command("migrate-set-capabilities",
tests/migration/guestperf/engine.py:            resp = src.command("migrate-set-parameters",
tests/migration/guestperf/engine.py:            resp = src.command("migrate-set-capabilities",
tests/migration/guestperf/engine.py:            resp = src.command("migrate-set-parameters",
tests/migration/guestperf/engine.py:            resp = dst.command("migrate-set-capabilities",
tests/migration/guestperf/engine.py:            resp = dst.command("migrate-set-parameters",
tests/migration/guestperf/engine.py:        resp = src.command("migrate", uri=connect_uri)
tests/migration/guestperf/engine.py:                    dst.command("cont")
tests/migration/guestperf/engine.py:                src.command("migrate_cancel")
tests/migration/guestperf/engine.py:                src.command("migrate_cancel")
tests/migration/guestperf/engine.py:                resp = src.command("migrate-start-postcopy")
tests/migration/guestperf/engine.py:                resp = src.command("stop")




> success by hand.. But that's not optimal. To simplify movement to
> vm.command() support same interface improvements like in vm.qmp() and
> rename to shorter vm.cmd().
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org>
> ---
>   python/qemu/machine/machine.py | 16 ++++++++++++---
>   tests/qemu-iotests/256         | 34 ++++++++++++++++----------------
>   tests/qemu-iotests/257         | 36 +++++++++++++++++-----------------
>   3 files changed, 48 insertions(+), 38 deletions(-)
> 
> diff --git a/python/qemu/machine/machine.py b/python/qemu/machine/machine.py
> index 07ac5a710b..a3fb840b93 100644
> --- a/python/qemu/machine/machine.py
> +++ b/python/qemu/machine/machine.py
> @@ -648,14 +648,24 @@ def qmp(self, cmd: str,
>               self._quit_issued = True
>           return ret
>   
> -    def command(self, cmd: str,
> -                conv_keys: bool = True,
> -                **args: Any) -> QMPReturnValue:
> +    def cmd(self, cmd: str,
> +            args_dict: Optional[Dict[str, object]] = None,
> +            conv_keys: Optional[bool] = None,
> +            **args: Any) -> QMPReturnValue:
>           """
>           Invoke a QMP command.
>           On success return the response dict.
>           On failure raise an exception.
>           """
> +        if args_dict is not None:
> +            assert not args
> +            assert conv_keys is None
> +            args = args_dict
> +            conv_keys = False
> +
> +        if conv_keys is None:
> +            conv_keys = True
> +
>           qmp_args = self._qmp_args(conv_keys, args)
>           ret = self._qmp.command(cmd, **qmp_args)
>           if cmd == 'quit':
> diff --git a/tests/qemu-iotests/256 b/tests/qemu-iotests/256
> index 13666813bd..fffc8ef055 100755
> --- a/tests/qemu-iotests/256
> +++ b/tests/qemu-iotests/256
> @@ -40,25 +40,25 @@ with iotests.FilePath('img0') as img0_path, \
>       def create_target(filepath, name, size):
>           basename = os.path.basename(filepath)
>           nodename = "file_{}".format(basename)
> -        log(vm.command('blockdev-create', job_id='job1',
> -                       options={
> -                           'driver': 'file',
> -                           'filename': filepath,
> -                           'size': 0,
> -                       }))
> +        log(vm.cmd('blockdev-create', job_id='job1',
> +                   options={
> +                       'driver': 'file',
> +                       'filename': filepath,
> +                       'size': 0,
> +                   }))
>           vm.run_job('job1')
> -        log(vm.command('blockdev-add', driver='file',
> -                       node_name=nodename, filename=filepath))
> -        log(vm.command('blockdev-create', job_id='job2',
> -                       options={
> -                           'driver': iotests.imgfmt,
> -                           'file': nodename,
> -                           'size': size,
> -                       }))
> +        log(vm.cmd('blockdev-add', driver='file',
> +                   node_name=nodename, filename=filepath))
> +        log(vm.cmd('blockdev-create', job_id='job2',
> +                   options={
> +                       'driver': iotests.imgfmt,
> +                       'file': nodename,
> +                       'size': size,
> +                   }))
>           vm.run_job('job2')
> -        log(vm.command('blockdev-add', driver=iotests.imgfmt,
> -                       node_name=name,
> -                       file=nodename))
> +        log(vm.cmd('blockdev-add', driver=iotests.imgfmt,
> +                   node_name=name,
> +                   file=nodename))
>   
>       log('--- Preparing images & VM ---\n')
>       vm.add_object('iothread,id=iothread0')
> diff --git a/tests/qemu-iotests/257 b/tests/qemu-iotests/257
> index e7e7a2317e..7d3720b8e5 100755
> --- a/tests/qemu-iotests/257
> +++ b/tests/qemu-iotests/257
> @@ -160,26 +160,26 @@ class Drive:
>           file_node_name = "file_{}".format(basename)
>           vm = self.vm
>   
> -        log(vm.command('blockdev-create', job_id='bdc-file-job',
> -                       options={
> -                           'driver': 'file',
> -                           'filename': self.path,
> -                           'size': 0,
> -                       }))
> +        log(vm.cmd('blockdev-create', job_id='bdc-file-job',
> +                   options={
> +                       'driver': 'file',
> +                       'filename': self.path,
> +                       'size': 0,
> +                   }))
>           vm.run_job('bdc-file-job')
> -        log(vm.command('blockdev-add', driver='file',
> -                       node_name=file_node_name, filename=self.path))
> -
> -        log(vm.command('blockdev-create', job_id='bdc-fmt-job',
> -                       options={
> -                           'driver': fmt,
> -                           'file': file_node_name,
> -                           'size': size,
> -                       }))
> +        log(vm.cmd('blockdev-add', driver='file',
> +                   node_name=file_node_name, filename=self.path))
> +
> +        log(vm.cmd('blockdev-create', job_id='bdc-fmt-job',
> +                   options={
> +                       'driver': fmt,
> +                       'file': file_node_name,
> +                       'size': size,
> +                   }))
>           vm.run_job('bdc-fmt-job')
> -        log(vm.command('blockdev-add', driver=fmt,
> -                       node_name=name,
> -                       file=file_node_name))
> +        log(vm.cmd('blockdev-add', driver=fmt,
> +                   node_name=name,
> +                   file=file_node_name))
>           self.fmt = fmt
>           self.size = size
>           self.node = name


-- 
Best regards,
Vladimir

Re: [PATCH 1/2] python/machine.py: upgrade vm.command() method

[John Snow]

[-- Attachment #1: Type: text/plain, Size: 15787 bytes --]

On Thu, May 26, 2022, 10:31 AM Vladimir Sementsov-Ogievskiy <
vsementsov@yandex-team.ru> wrote:

> On 4/8/22 20:02, Vladimir Sementsov-Ogievskiy wrote:
> > The method is not popular, we prefer use vm.qmp() and then check
>
> Suddenly I found, that I missed a lot of existing users: in scripts, in
> avocado tests.
>
> Do you prefer to rename the method to "cmd()", and change all the
> occurrences, or keep longer "command()" name and update the second patch?
>

I don't have a strong preference, I think.

In (async) qmp I use .execute() as the form that raises exception, and
._raw() as the form that doesn't. I use execute_msg() as an
exception-raising form that takes a Mapping[str, obj].

Notably, I tried to hide any interface that didn't raise exception, and the
interfaces that remain always return the inner return field and not the
entire wire object.

command() IIRC has historically been the exception-raising version and
cmd() has been the C-like version. (cmd_obj works like my execute_msg,
except it doesn't raise, and returns the entire reply.)

command() is longer, but there's precedent and continuity for it working
this way. But shorter names are nicer for line length, so...

...Go with what you feel is subjectively nicest? (That's not helpful,
sorry.)

oh, also: IIRC, command() also does not return the entire response object.
This is how execute() works, but it might be a lot of churn to convert
users of cmd() over to this form. It's something I want to do eventually
anyway, but it's a lot for me to dump on your plate, so don't worry about
that aspect.

--js


>
> $ git grep '\.command('
> docs/devel/testing.rst:          res =
> self.vm.command('human-monitor-command',
> docs/devel/testing.rst:          first_res = first_machine.command(
> docs/devel/testing.rst:          second_res = second_machine.command(
> docs/devel/testing.rst:          third_res =
> self.get_vm(name='third_machine').command(
> python/qemu/machine/machine.py:        ret = self._qmp.command(cmd,
> **qmp_args)
> python/qemu/utils/qemu_ga_client.py:            return
> self.command('guest-' + name.replace('_', '-'), **kwds)
> python/qemu/utils/qom.py:        rsp = self.qmp.command(
> python/qemu/utils/qom.py:        rsp = self.qmp.command(
> python/qemu/utils/qom.py:                rsp = self.qmp.command('qom-get',
> path=path,
> python/qemu/utils/qom_common.py:        rsp = self.qmp.command('qom-list',
> path=path)
> python/qemu/utils/qom_fuse.py:            data =
> str(self.qmp.command('qom-get', path=path, property=prop))
> python/qemu/utils/qom_fuse.py:        return prefix +
> str(self.qmp.command('qom-get', path=path,
> scripts/device-crash-test:    types = vm.command('qom-list-types',
> **kwargs)
> scripts/device-crash-test:    devhelp =
> vm.command('human-monitor-command', **args)
> scripts/device-crash-test:            self.machines = list(m['name'] for m
> in vm.command('query-machines'))
> scripts/device-crash-test:            self.kvm_available =
> vm.command('query-kvm')['enabled']
> scripts/render_block_graph.py:    bds_nodes =
> qmp.command('query-named-block-nodes')
> scripts/render_block_graph.py:    job_nodes =
> qmp.command('query-block-jobs')
> scripts/render_block_graph.py:    block_graph =
> qmp.command('x-debug-query-block-graph')
> tests/avocado/avocado_qemu/__init__.py:        res =
> self.vm.command('human-monitor-command',
> tests/avocado/cpu_queries.py:        cpus =
> self.vm.command('query-cpu-definitions')
> tests/avocado/cpu_queries.py:            e =
> self.vm.command('query-cpu-model-expansion', model=model, type='full')
> tests/avocado/hotplug_cpu.py:        self.vm.command('device_add',
> tests/avocado/info_usernet.py:        res =
> self.vm.command('human-monitor-command',
> tests/avocado/machine_arm_integratorcp.py:
> self.vm.command('human-monitor-command', command_line='stop')
> tests/avocado/machine_arm_integratorcp.py:
> self.vm.command('human-monitor-command',
> tests/avocado/machine_m68k_nextcube.py:
> self.vm.command('human-monitor-command',
> tests/avocado/machine_mips_malta.py:
> self.vm.command('human-monitor-command', command_line='stop')
> tests/avocado/machine_mips_malta.py:
> self.vm.command('human-monitor-command',
> tests/avocado/machine_s390_ccw_virtio.py:
> self.vm.command('device_del', id='rn1')
> tests/avocado/machine_s390_ccw_virtio.py:
> self.vm.command('device_del', id='rn2')
> tests/avocado/machine_s390_ccw_virtio.py:
> self.vm.command('device_add', driver='virtio-net-ccw',
> tests/avocado/machine_s390_ccw_virtio.py:
> self.vm.command('device_del', id='net_4711')
> tests/avocado/machine_s390_ccw_virtio.py:
> self.vm.command('human-monitor-command', command_line='balloon 96')
> tests/avocado/machine_s390_ccw_virtio.py:
> self.vm.command('human-monitor-command', command_line='balloon 128')
> tests/avocado/machine_s390_ccw_virtio.py:
> self.vm.command('screendump', filename=ppmfile.name)
> tests/avocado/machine_s390_ccw_virtio.py:
> self.vm.command('object-add', qom_type='cryptodev-backend-builtin',
> tests/avocado/machine_s390_ccw_virtio.py:
> self.vm.command('device_add', driver='virtio-crypto-ccw', id='crypdev0',
> tests/avocado/machine_s390_ccw_virtio.py:
> self.vm.command('device_del', id='crypdev0')
> tests/avocado/machine_s390_ccw_virtio.py:
> self.vm.command('object-del', id='cbe0')
> tests/avocado/migration.py:        return
> vm.command('query-migrate')['status'] in ('completed', 'failed')
> tests/avocado/migration.py:
> self.assertEqual(src_vm.command('query-migrate')['status'], 'completed')
> tests/avocado/migration.py:
> self.assertEqual(dst_vm.command('query-migrate')['status'], 'completed')
> tests/avocado/migration.py:
> self.assertEqual(dst_vm.command('query-status')['status'], 'running')
> tests/avocado/migration.py:
> self.assertEqual(src_vm.command('query-status')['status'],'postmigrate')
> tests/avocado/pc_cpu_hotplug_props.py:
> self.assertEquals(len(self.vm.command('query-cpus-fast')), 2)
> tests/avocado/version.py:        res =
> self.vm.command('human-monitor-command',
> tests/avocado/virtio_check_params.py:        output =
> vm.command('human-monitor-command',
> tests/avocado/virtio_check_params.py:            machines = [m['name'] for
> m in vm.command('query-machines')]
> tests/avocado/virtio_version.py:    return devtype in [d['name'] for d in
> vm.command('qom-list-types', implements=implements)]
> tests/avocado/virtio_version.py:            pcibuses =
> vm.command('query-pci')
> tests/avocado/x86_cpu_model_versions.py:        cpus = dict((m['name'], m)
> for m in self.vm.command('query-cpu-definitions'))
> tests/avocado/x86_cpu_model_versions.py:        cpus = dict((m['name'], m)
> for m in self.vm.command('query-cpu-definitions'))
> tests/avocado/x86_cpu_model_versions.py:        cpus = dict((m['name'], m)
> for m in self.vm.command('query-cpu-definitions'))
> tests/avocado/x86_cpu_model_versions.py:        cpu_path =
> self.vm.command('query-cpus-fast')[0].get('qom-path')
> tests/avocado/x86_cpu_model_versions.py:        return
> self.vm.command('qom-get', path=cpu_path, property=prop)
> tests/docker/docker.py:        dkr.command(cmd="pull", quiet=args.quiet,
> tests/docker/docker.py:        dkr.command(cmd="tag", quiet=args.quiet,
> tests/docker/docker.py:        return Docker().command("images", argv,
> args.quiet)
> tests/migration/guestperf/engine.py:        info =
> vm.command("query-migrate")
> tests/migration/guestperf/engine.py:        vcpus =
> src.command("query-cpus-fast")
> tests/migration/guestperf/engine.py:            resp =
> src.command("migrate-set-capabilities",
> tests/migration/guestperf/engine.py:            resp =
> src.command("migrate-set-parameters",
> tests/migration/guestperf/engine.py:            resp =
> src.command("migrate-set-capabilities",
> tests/migration/guestperf/engine.py:            resp =
> dst.command("migrate-set-capabilities",
> tests/migration/guestperf/engine.py:        resp =
> src.command("migrate-set-parameters",
> tests/migration/guestperf/engine.py:        resp =
> src.command("migrate-set-parameters",
> tests/migration/guestperf/engine.py:            resp =
> src.command("migrate-set-capabilities",
> tests/migration/guestperf/engine.py:            resp =
> src.command("migrate-set-parameters",
> tests/migration/guestperf/engine.py:            resp =
> dst.command("migrate-set-capabilities",
> tests/migration/guestperf/engine.py:            resp =
> dst.command("migrate-set-parameters",
> tests/migration/guestperf/engine.py:            resp =
> src.command("migrate-set-capabilities",
> tests/migration/guestperf/engine.py:            resp =
> dst.command("migrate-set-capabilities",
> tests/migration/guestperf/engine.py:            resp =
> src.command("migrate-set-parameters",
> tests/migration/guestperf/engine.py:            resp =
> src.command("migrate-set-capabilities",
> tests/migration/guestperf/engine.py:            resp =
> src.command("migrate-set-parameters",
> tests/migration/guestperf/engine.py:            resp =
> dst.command("migrate-set-capabilities",
> tests/migration/guestperf/engine.py:            resp =
> dst.command("migrate-set-parameters",
> tests/migration/guestperf/engine.py:        resp = src.command("migrate",
> uri=connect_uri)
> tests/migration/guestperf/engine.py:                    dst.command("cont")
> tests/migration/guestperf/engine.py:
> src.command("migrate_cancel")
> tests/migration/guestperf/engine.py:
> src.command("migrate_cancel")
> tests/migration/guestperf/engine.py:                resp =
> src.command("migrate-start-postcopy")
> tests/migration/guestperf/engine.py:                resp =
> src.command("stop")
>
>
>
>
> > success by hand.. But that's not optimal. To simplify movement to
> > vm.command() support same interface improvements like in vm.qmp() and
> > rename to shorter vm.cmd().
> >
> > Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org>
> > ---
> >   python/qemu/machine/machine.py | 16 ++++++++++++---
> >   tests/qemu-iotests/256         | 34 ++++++++++++++++----------------
> >   tests/qemu-iotests/257         | 36 +++++++++++++++++-----------------
> >   3 files changed, 48 insertions(+), 38 deletions(-)
> >
> > diff --git a/python/qemu/machine/machine.py
> b/python/qemu/machine/machine.py
> > index 07ac5a710b..a3fb840b93 100644
> > --- a/python/qemu/machine/machine.py
> > +++ b/python/qemu/machine/machine.py
> > @@ -648,14 +648,24 @@ def qmp(self, cmd: str,
> >               self._quit_issued = True
> >           return ret
> >
> > -    def command(self, cmd: str,
> > -                conv_keys: bool = True,
> > -                **args: Any) -> QMPReturnValue:
> > +    def cmd(self, cmd: str,
> > +            args_dict: Optional[Dict[str, object]] = None,
> > +            conv_keys: Optional[bool] = None,
> > +            **args: Any) -> QMPReturnValue:
> >           """
> >           Invoke a QMP command.
> >           On success return the response dict.
> >           On failure raise an exception.
> >           """
> > +        if args_dict is not None:
> > +            assert not args
> > +            assert conv_keys is None
> > +            args = args_dict
> > +            conv_keys = False
> > +
> > +        if conv_keys is None:
> > +            conv_keys = True
> > +
> >           qmp_args = self._qmp_args(conv_keys, args)
> >           ret = self._qmp.command(cmd, **qmp_args)
> >           if cmd == 'quit':
> > diff --git a/tests/qemu-iotests/256 b/tests/qemu-iotests/256
> > index 13666813bd..fffc8ef055 100755
> > --- a/tests/qemu-iotests/256
> > +++ b/tests/qemu-iotests/256
> > @@ -40,25 +40,25 @@ with iotests.FilePath('img0') as img0_path, \
> >       def create_target(filepath, name, size):
> >           basename = os.path.basename(filepath)
> >           nodename = "file_{}".format(basename)
> > -        log(vm.command('blockdev-create', job_id='job1',
> > -                       options={
> > -                           'driver': 'file',
> > -                           'filename': filepath,
> > -                           'size': 0,
> > -                       }))
> > +        log(vm.cmd('blockdev-create', job_id='job1',
> > +                   options={
> > +                       'driver': 'file',
> > +                       'filename': filepath,
> > +                       'size': 0,
> > +                   }))
> >           vm.run_job('job1')
> > -        log(vm.command('blockdev-add', driver='file',
> > -                       node_name=nodename, filename=filepath))
> > -        log(vm.command('blockdev-create', job_id='job2',
> > -                       options={
> > -                           'driver': iotests.imgfmt,
> > -                           'file': nodename,
> > -                           'size': size,
> > -                       }))
> > +        log(vm.cmd('blockdev-add', driver='file',
> > +                   node_name=nodename, filename=filepath))
> > +        log(vm.cmd('blockdev-create', job_id='job2',
> > +                   options={
> > +                       'driver': iotests.imgfmt,
> > +                       'file': nodename,
> > +                       'size': size,
> > +                   }))
> >           vm.run_job('job2')
> > -        log(vm.command('blockdev-add', driver=iotests.imgfmt,
> > -                       node_name=name,
> > -                       file=nodename))
> > +        log(vm.cmd('blockdev-add', driver=iotests.imgfmt,
> > +                   node_name=name,
> > +                   file=nodename))
> >
> >       log('--- Preparing images & VM ---\n')
> >       vm.add_object('iothread,id=iothread0')
> > diff --git a/tests/qemu-iotests/257 b/tests/qemu-iotests/257
> > index e7e7a2317e..7d3720b8e5 100755
> > --- a/tests/qemu-iotests/257
> > +++ b/tests/qemu-iotests/257
> > @@ -160,26 +160,26 @@ class Drive:
> >           file_node_name = "file_{}".format(basename)
> >           vm = self.vm
> >
> > -        log(vm.command('blockdev-create', job_id='bdc-file-job',
> > -                       options={
> > -                           'driver': 'file',
> > -                           'filename': self.path,
> > -                           'size': 0,
> > -                       }))
> > +        log(vm.cmd('blockdev-create', job_id='bdc-file-job',
> > +                   options={
> > +                       'driver': 'file',
> > +                       'filename': self.path,
> > +                       'size': 0,
> > +                   }))
> >           vm.run_job('bdc-file-job')
> > -        log(vm.command('blockdev-add', driver='file',
> > -                       node_name=file_node_name, filename=self.path))
> > -
> > -        log(vm.command('blockdev-create', job_id='bdc-fmt-job',
> > -                       options={
> > -                           'driver': fmt,
> > -                           'file': file_node_name,
> > -                           'size': size,
> > -                       }))
> > +        log(vm.cmd('blockdev-add', driver='file',
> > +                   node_name=file_node_name, filename=self.path))
> > +
> > +        log(vm.cmd('blockdev-create', job_id='bdc-fmt-job',
> > +                   options={
> > +                       'driver': fmt,
> > +                       'file': file_node_name,
> > +                       'size': size,
> > +                   }))
> >           vm.run_job('bdc-fmt-job')
> > -        log(vm.command('blockdev-add', driver=fmt,
> > -                       node_name=name,
> > -                       file=file_node_name))
> > +        log(vm.cmd('blockdev-add', driver=fmt,
> > +                   node_name=name,
> > +                   file=file_node_name))
> >           self.fmt = fmt
> >           self.size = size
> >           self.node = name
>
>
> --
> Best regards,
> Vladimir
>

[-- Attachment #2: Type: text/html, Size: 21122 bytes --]

[PATCH 2/2] iotests: use vm.cmd() instead of vm.qmp() where appropriate

[Vladimir Sementsov-Ogievskiy]

Checking success by hand every time is tedious. Let's use cmd() method
instead which does this check for us.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org>
---
 tests/qemu-iotests/030                        | 168 +++----
 tests/qemu-iotests/040                        | 167 +++---
 tests/qemu-iotests/041                        | 474 ++++++++----------
 tests/qemu-iotests/045                        |  15 +-
 tests/qemu-iotests/055                        |  61 +--
 tests/qemu-iotests/056                        |  23 +-
 tests/qemu-iotests/093                        |  41 +-
 tests/qemu-iotests/118                        | 221 ++++----
 tests/qemu-iotests/124                        |  69 ++-
 tests/qemu-iotests/129                        |  13 +-
 tests/qemu-iotests/132                        |   5 +-
 tests/qemu-iotests/139                        |  43 +-
 tests/qemu-iotests/147                        |  30 +-
 tests/qemu-iotests/151                        |  40 +-
 tests/qemu-iotests/155                        |  53 +-
 tests/qemu-iotests/165                        |   7 +-
 tests/qemu-iotests/196                        |   3 +-
 tests/qemu-iotests/205                        |   6 +-
 tests/qemu-iotests/245                        | 245 ++++-----
 tests/qemu-iotests/264                        |  31 +-
 tests/qemu-iotests/281                        |  21 +-
 tests/qemu-iotests/295                        |  27 +-
 tests/qemu-iotests/296                        |  14 +-
 tests/qemu-iotests/298                        |  13 +-
 tests/qemu-iotests/300                        |  50 +-
 tests/qemu-iotests/iotests.py                 |   6 +-
 .../tests/migrate-bitmaps-postcopy-test       |  31 +-
 tests/qemu-iotests/tests/migrate-bitmaps-test |  37 +-
 .../qemu-iotests/tests/migrate-during-backup  |  40 +-
 .../qemu-iotests/tests/migration-permissions  |   9 +-
 tests/qemu-iotests/tests/mirror-top-perms     |  15 +-
 31 files changed, 773 insertions(+), 1205 deletions(-)

diff --git a/tests/qemu-iotests/030 b/tests/qemu-iotests/030
index 18eddcc734..7c79fe041d 100755
--- a/tests/qemu-iotests/030
+++ b/tests/qemu-iotests/030
@@ -56,8 +56,7 @@ class TestSingleDrive(iotests.QMPTestCase):
     def test_stream(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('block-stream', device='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='drive0')
 
         self.wait_until_completed()
 
@@ -75,8 +74,7 @@ class TestSingleDrive(iotests.QMPTestCase):
                             qemu_io('-f', iotests.imgfmt, '-rU', '-c', 'map', mid_img),
                             'image file map matches backing file before streaming')
 
-        result = self.vm.qmp('block-stream', device='mid', job_id='stream-mid')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='mid', job_id='stream-mid')
 
         self.wait_until_completed(drive='stream-mid')
 
@@ -91,8 +89,7 @@ class TestSingleDrive(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
 
         self.vm.pause_drive('drive0')
-        result = self.vm.qmp('block-stream', device='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='drive0')
 
         self.pause_job('drive0', wait=False)
         self.vm.resume_drive('drive0')
@@ -105,8 +102,7 @@ class TestSingleDrive(iotests.QMPTestCase):
         result = self.vm.qmp('query-block-jobs')
         self.assert_qmp(result, 'return[0]/offset', offset)
 
-        result = self.vm.qmp('block-job-resume', device='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-resume', device='drive0')
 
         self.wait_until_completed()
 
@@ -124,8 +120,7 @@ class TestSingleDrive(iotests.QMPTestCase):
         empty_map = qemu_io('-f', iotests.imgfmt, '-rU', '-c', 'map', test_img)
 
         # This is a no-op: no data should ever be copied from the base image
-        result = self.vm.qmp('block-stream', device='drive0', base=mid_img)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='drive0', base=mid_img)
 
         self.wait_until_completed()
 
@@ -138,8 +133,7 @@ class TestSingleDrive(iotests.QMPTestCase):
     def test_stream_partial(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('block-stream', device='drive0', base=backing_img)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='drive0', base=backing_img)
 
         self.wait_until_completed()
 
@@ -165,24 +159,22 @@ class TestSingleDrive(iotests.QMPTestCase):
             qemu_img('create', '-f', iotests.imgfmt, ro_top_path,
                      str(self.image_len))
 
-            result = self.vm.qmp('blockdev-add',
-                                 node_name='ro-top',
-                                 driver=iotests.imgfmt,
-                                 read_only=True,
-                                 file={
-                                     'driver': 'file',
-                                     'filename': ro_top_path,
-                                     'read-only': True
-                                 },
-                                 backing='mid')
-            self.assert_qmp(result, 'return', {})
+            self.vm.cmd('blockdev-add',
+                        node_name='ro-top',
+                        driver=iotests.imgfmt,
+                        read_only=True,
+                        file={
+                            'driver': 'file',
+                            'filename': ro_top_path,
+                            'read-only': True
+                        },
+                        backing='mid')
 
             result = self.vm.qmp('block-stream', job_id='stream',
                                  device='ro-top', base_node='base')
             self.assert_qmp(result, 'error/desc', 'Block node is read-only')
 
-            result = self.vm.qmp('blockdev-del', node_name='ro-top')
-            self.assert_qmp(result, 'return', {})
+            self.vm.cmd('blockdev-del', node_name='ro-top')
 
 
 class TestParallelOps(iotests.QMPTestCase):
@@ -246,10 +238,9 @@ class TestParallelOps(iotests.QMPTestCase):
             node_name = 'node%d' % i
             job_id = 'stream-%s' % node_name
             pending_jobs.append(job_id)
-            result = self.vm.qmp('block-stream', device=node_name,
-                                 job_id=job_id, bottom=f'node{i-1}',
-                                 speed=1024)
-            self.assert_qmp(result, 'return', {})
+            self.vm.cmd('block-stream', device=node_name,
+                        job_id=job_id, bottom=f'node{i-1}',
+                        speed=1024)
 
         # Do this in reverse: After unthrottling them, some jobs may finish
         # before we have unthrottled all of them.  This will drain their
@@ -261,8 +252,7 @@ class TestParallelOps(iotests.QMPTestCase):
         # Starting from the top (i.e. in reverse) does not have this problem:
         # When a job finishes, the ones below it are not advanced.
         for job in reversed(pending_jobs):
-            result = self.vm.qmp('block-job-set-speed', device=job, speed=0)
-            self.assert_qmp(result, 'return', {})
+            self.vm.cmd('block-job-set-speed', device=job, speed=0)
 
         # Wait for all jobs to be finished.
         while len(pending_jobs) > 0:
@@ -288,10 +278,9 @@ class TestParallelOps(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
 
         # Set a speed limit to make sure that this job blocks the rest
-        result = self.vm.qmp('block-stream', device='node4',
-                             job_id='stream-node4', base=self.imgs[1],
-                             filter_node_name='stream-filter', speed=1024*1024)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='node4',
+                    job_id='stream-node4', base=self.imgs[1],
+                    filter_node_name='stream-filter', speed=1024*1024)
 
         result = self.vm.qmp('block-stream', device='node5', job_id='stream-node5', base=self.imgs[2])
         self.assert_qmp(result, 'error/desc',
@@ -319,8 +308,7 @@ class TestParallelOps(iotests.QMPTestCase):
         self.assert_qmp(result, 'error/desc',
             "Node 'node2' is busy: block device is in use by block job: stream")
 
-        result = self.vm.qmp('block-job-set-speed', device='stream-node4', speed=0)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-set-speed', device='stream-node4', speed=0)
 
         self.wait_until_completed(drive='stream-node4')
         self.assert_no_active_block_jobs()
@@ -332,8 +320,7 @@ class TestParallelOps(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
 
         # Set a speed limit to make sure that this job blocks the rest
-        result = self.vm.qmp('block-commit', device='drive0', top=self.imgs[5], base=self.imgs[3], job_id='commit-node3', speed=1024*1024)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit', device='drive0', top=self.imgs[5], base=self.imgs[3], job_id='commit-node3', speed=1024*1024)
 
         result = self.vm.qmp('block-stream', device='node3', job_id='stream-node3')
         self.assert_qmp(result, 'error/desc',
@@ -356,8 +343,7 @@ class TestParallelOps(iotests.QMPTestCase):
         self.assert_qmp(result, 'error/desc',
             "Node 'drive0' is busy: block device is in use by block job: commit")
 
-        result = self.vm.qmp('block-job-set-speed', device='commit-node3', speed=0)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-set-speed', device='commit-node3', speed=0)
 
         self.wait_until_completed(drive='commit-node3')
 
@@ -368,23 +354,20 @@ class TestParallelOps(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
 
         # Set a speed limit to make sure that this job blocks the rest
-        result = self.vm.qmp('block-commit', device='drive0', base=self.imgs[3], job_id='commit-drive0', speed=1024*1024)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit', device='drive0', base=self.imgs[3], job_id='commit-drive0', speed=1024*1024)
 
         result = self.vm.qmp('block-stream', device='node5', base=self.imgs[3], job_id='stream-node6')
         self.assert_qmp(result, 'error/desc',
             "Node 'node5' is busy: block device is in use by block job: commit")
 
-        result = self.vm.qmp('block-job-set-speed', device='commit-drive0', speed=0)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-set-speed', device='commit-drive0', speed=0)
 
         event = self.vm.event_wait(name='BLOCK_JOB_READY')
         self.assert_qmp(event, 'data/device', 'commit-drive0')
         self.assert_qmp(event, 'data/type', 'commit')
         self.assert_qmp_absent(event, 'data/error')
 
-        result = self.vm.qmp('block-job-complete', device='commit-drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-complete', device='commit-drive0')
 
         self.wait_until_completed(drive='commit-drive0')
 
@@ -395,18 +378,16 @@ class TestParallelOps(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
 
         # Commit from node2 into node0
-        result = self.vm.qmp('block-commit', device='drive0',
-                             top=self.imgs[2], base=self.imgs[0],
-                             filter_node_name='commit-filter', speed=1024*1024)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit', device='drive0',
+                    top=self.imgs[2], base=self.imgs[0],
+                    filter_node_name='commit-filter', speed=1024*1024)
 
         # Stream from node2 into node4
         result = self.vm.qmp('block-stream', device='node4', base_node='node2', job_id='node4')
         self.assert_qmp(result, 'error/desc',
             "Cannot freeze 'backing' link to 'commit-filter'")
 
-        result = self.vm.qmp('block-job-set-speed', device='drive0', speed=0)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-set-speed', device='drive0', speed=0)
 
         self.wait_until_completed()
         self.assert_no_active_block_jobs()
@@ -419,18 +400,15 @@ class TestParallelOps(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
 
         # Commit from node2 into node0
-        result = self.vm.qmp('block-commit', device='drive0',
-                             top_node='node2', base_node='node0',
-                             filter_node_name='commit-filter', speed=1024*1024)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit', device='drive0',
+                    top_node='node2', base_node='node0',
+                    filter_node_name='commit-filter', speed=1024*1024)
 
         # Stream from node2 into node4
-        result = self.vm.qmp('block-stream', device='node4',
-                             base_node='commit-filter', job_id='node4')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='node4',
+                    base_node='commit-filter', job_id='node4')
 
-        result = self.vm.qmp('block-job-set-speed', device='drive0', speed=0)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-set-speed', device='drive0', speed=0)
 
         self.vm.run_job(job='drive0', auto_dismiss=True)
         self.vm.run_job(job='node4', auto_dismiss=True)
@@ -449,12 +427,10 @@ class TestParallelOps(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
 
         # Stream from node0 into node2
-        result = self.vm.qmp('block-stream', device='node2', base_node='node0', job_id='node2')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='node2', base_node='node0', job_id='node2')
 
         # Commit from the active layer into node3
-        result = self.vm.qmp('block-commit', device='drive0', base=self.imgs[3])
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit', device='drive0', base=self.imgs[3])
 
         # Wait for all jobs to be finished.
         pending_jobs = ['node2', 'drive0']
@@ -481,16 +457,13 @@ class TestParallelOps(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
 
         # Stream from node0 into node4
-        result = self.vm.qmp('block-stream', device='node4', base_node='node0', job_id='node4', speed=1024*1024)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='node4', base_node='node0', job_id='node4', speed=1024*1024)
 
         # Commit from the active layer into node5
-        result = self.vm.qmp('block-commit', device='drive0', base=self.imgs[5], speed=1024*1024)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit', device='drive0', base=self.imgs[5], speed=1024*1024)
 
         for job in ['drive0', 'node4']:
-            result = self.vm.qmp('block-job-set-speed', device=job, speed=0)
-            self.assert_qmp(result, 'return', {})
+            self.vm.cmd('block-job-set-speed', device=job, speed=0)
 
         # Wait for all jobs to be finished.
         pending_jobs = ['node4', 'drive0']
@@ -539,8 +512,7 @@ class TestParallelOps(iotests.QMPTestCase):
             "'base' and 'base-node' cannot be specified at the same time")
 
         # Success: the base node is a backing file of the top node
-        result = self.vm.qmp('block-stream', device='node4', base_node='node2', job_id='stream')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='node4', base_node='node2', job_id='stream')
 
         self.wait_until_completed(drive='stream')
 
@@ -594,8 +566,7 @@ class TestQuorum(iotests.QMPTestCase):
 
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('block-stream', device='node0', job_id='stream-node0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='node0', job_id='stream-node0')
 
         self.wait_until_completed(drive='stream-node0')
 
@@ -623,8 +594,7 @@ class TestSmallerBackingFile(iotests.QMPTestCase):
     def test_stream(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('block-stream', device='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='drive0')
 
         self.wait_until_completed()
 
@@ -681,8 +651,7 @@ class TestEIO(TestErrors):
     def test_report(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('block-stream', device='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='drive0')
 
         completed = False
         error = False
@@ -709,8 +678,7 @@ class TestEIO(TestErrors):
     def test_ignore(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('block-stream', device='drive0', on_error='ignore')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='drive0', on_error='ignore')
 
         error = False
         completed = False
@@ -743,8 +711,7 @@ class TestEIO(TestErrors):
     def test_stop(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('block-stream', device='drive0', on_error='stop')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='drive0', on_error='stop')
 
         error = False
         completed = False
@@ -766,8 +733,7 @@ class TestEIO(TestErrors):
                     self.assert_qmp(result, 'return[0]/offset', self.STREAM_BUFFER_SIZE)
                     self.assert_qmp(result, 'return[0]/io-status', 'failed')
 
-                    result = self.vm.qmp('block-job-resume', device='drive0')
-                    self.assert_qmp(result, 'return', {})
+                    self.vm.cmd('block-job-resume', device='drive0')
 
                     result = self.vm.qmp('query-block-jobs')
                     if result == {'return': []}:
@@ -793,8 +759,7 @@ class TestEIO(TestErrors):
     def test_enospc(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('block-stream', device='drive0', on_error='enospc')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='drive0', on_error='enospc')
 
         completed = False
         error = False
@@ -839,8 +804,7 @@ class TestENOSPC(TestErrors):
     def test_enospc(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('block-stream', device='drive0', on_error='enospc')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='drive0', on_error='enospc')
 
         error = False
         completed = False
@@ -862,8 +826,7 @@ class TestENOSPC(TestErrors):
                     self.assert_qmp(result, 'return[0]/offset', self.STREAM_BUFFER_SIZE)
                     self.assert_qmp(result, 'return[0]/io-status', 'nospace')
 
-                    result = self.vm.qmp('block-job-resume', device='drive0')
-                    self.assert_qmp(result, 'return', {})
+                    self.vm.cmd('block-job-resume', device='drive0')
 
                     result = self.vm.qmp('query-block-jobs')
                     if result == {'return': []}:
@@ -908,8 +871,7 @@ class TestStreamStop(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
 
         self.vm.pause_drive('drive0')
-        result = self.vm.qmp('block-stream', device='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='drive0')
 
         time.sleep(0.1)
         events = self.vm.get_qmp_events(wait=False)
@@ -942,11 +904,9 @@ class TestSetSpeed(iotests.QMPTestCase):
     def perf_test_throughput(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('block-stream', device='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='drive0')
 
-        result = self.vm.qmp('block-job-set-speed', device='drive0', speed=8 * 1024 * 1024)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-set-speed', device='drive0', speed=8 * 1024 * 1024)
 
         self.wait_until_completed()
 
@@ -956,16 +916,14 @@ class TestSetSpeed(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
 
         self.vm.pause_drive('drive0')
-        result = self.vm.qmp('block-stream', device='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='drive0')
 
         # Default speed is 0
         result = self.vm.qmp('query-block-jobs')
         self.assert_qmp(result, 'return[0]/device', 'drive0')
         self.assert_qmp(result, 'return[0]/speed', 0)
 
-        result = self.vm.qmp('block-job-set-speed', device='drive0', speed=8 * 1024 * 1024)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-set-speed', device='drive0', speed=8 * 1024 * 1024)
 
         # Ensure the speed we set was accepted
         result = self.vm.qmp('query-block-jobs')
@@ -976,8 +934,7 @@ class TestSetSpeed(iotests.QMPTestCase):
         self.vm.pause_drive('drive0')
 
         # Check setting speed in block-stream works
-        result = self.vm.qmp('block-stream', device='drive0', speed=4 * 1024 * 1024)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='drive0', speed=4 * 1024 * 1024)
 
         result = self.vm.qmp('query-block-jobs')
         self.assert_qmp(result, 'return[0]/device', 'drive0')
@@ -994,8 +951,7 @@ class TestSetSpeed(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
 
         self.vm.pause_drive('drive0')
-        result = self.vm.qmp('block-stream', device='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', device='drive0')
 
         result = self.vm.qmp('block-job-set-speed', device='drive0', speed=-1)
         self.assert_qmp(result, 'error/desc', "Parameter 'speed' expects a non-negative value")
diff --git a/tests/qemu-iotests/040 b/tests/qemu-iotests/040
index 0e1cfd7e49..d43f3c3130 100755
--- a/tests/qemu-iotests/040
+++ b/tests/qemu-iotests/040
@@ -61,16 +61,14 @@ class ImageCommitTestCase(iotests.QMPTestCase):
     def run_commit_test(self, top, base, need_ready=False, node_names=False):
         self.assert_no_active_block_jobs()
         if node_names:
-            result = self.vm.qmp('block-commit', device='drive0', top_node=top, base_node=base)
+            self.vm.cmd('block-commit', device='drive0', top_node=top, base_node=base)
         else:
-            result = self.vm.qmp('block-commit', device='drive0', top=top, base=base)
-        self.assert_qmp(result, 'return', {})
+            self.vm.cmd('block-commit', device='drive0', top=top, base=base)
         self.wait_for_complete(need_ready)
 
     def run_default_commit_test(self):
         self.assert_no_active_block_jobs()
-        result = self.vm.qmp('block-commit', device='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit', device='drive0')
         self.wait_for_complete()
 
 class TestSingleDrive(ImageCommitTestCase):
@@ -111,38 +109,30 @@ class TestSingleDrive(ImageCommitTestCase):
 
     @iotests.skip_if_unsupported(['throttle'])
     def test_commit_with_filter_and_quit(self):
-        result = self.vm.qmp('object-add', qom_type='throttle-group', id='tg')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('object-add', qom_type='throttle-group', id='tg')
 
         # Add a filter outside of the backing chain
-        result = self.vm.qmp('blockdev-add', driver='throttle', node_name='filter', throttle_group='tg', file='mid')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', driver='throttle', node_name='filter', throttle_group='tg', file='mid')
 
-        result = self.vm.qmp('block-commit', device='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit', device='drive0')
 
         # Quit immediately, thus forcing a simultaneous cancel of the
         # block job and a bdrv_drain_all()
-        result = self.vm.qmp('quit')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('quit')
 
     # Same as above, but this time we add the filter after starting the job
     @iotests.skip_if_unsupported(['throttle'])
     def test_commit_plus_filter_and_quit(self):
-        result = self.vm.qmp('object-add', qom_type='throttle-group', id='tg')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('object-add', qom_type='throttle-group', id='tg')
 
-        result = self.vm.qmp('block-commit', device='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit', device='drive0')
 
         # Add a filter outside of the backing chain
-        result = self.vm.qmp('blockdev-add', driver='throttle', node_name='filter', throttle_group='tg', file='mid')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', driver='throttle', node_name='filter', throttle_group='tg', file='mid')
 
         # Quit immediately, thus forcing a simultaneous cancel of the
         # block job and a bdrv_drain_all()
-        result = self.vm.qmp('quit')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('quit')
 
     def test_device_not_found(self):
         result = self.vm.qmp('block-commit', device='nonexistent', top='%s' % mid_img)
@@ -215,8 +205,7 @@ class TestSingleDrive(ImageCommitTestCase):
     def test_top_node_in_wrong_chain(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('blockdev-add', driver='null-co', node_name='null')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', driver='null-co', node_name='null')
 
         result = self.vm.qmp('block-commit', device='drive0', top_node='null', base_node='base')
         self.assert_qmp(result, 'error/class', 'GenericError')
@@ -229,11 +218,9 @@ class TestSingleDrive(ImageCommitTestCase):
             return
 
         self.assert_no_active_block_jobs()
-        result = self.vm.qmp('block-commit', device='drive0', top=mid_img,
-                             base=backing_img, speed=(self.image_len // 4))
-        self.assert_qmp(result, 'return', {})
-        result = self.vm.qmp('device_del', id='scsi0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit', device='drive0', top=mid_img,
+                    base=backing_img, speed=(self.image_len // 4))
+        self.vm.cmd('device_del', id='scsi0')
 
         cancelled = False
         deleted = False
@@ -259,9 +246,8 @@ class TestSingleDrive(ImageCommitTestCase):
             return
 
         self.assert_no_active_block_jobs()
-        result = self.vm.qmp('block-commit', device='drive0', top=mid_img,
-                             base=backing_img, speed=(self.image_len // 4))
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit', device='drive0', top=mid_img,
+                    base=backing_img, speed=(self.image_len // 4))
 
         result = self.vm.qmp('query-block')
         self.assert_qmp(result, 'return[0]/inserted/file', test_img)
@@ -396,8 +382,7 @@ class TestSetSpeed(ImageCommitTestCase):
         self.assert_no_active_block_jobs()
 
         self.vm.pause_drive('drive0')
-        result = self.vm.qmp('block-commit', device='drive0', top=mid_img, speed=1024 * 1024)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit', device='drive0', top=mid_img, speed=1024 * 1024)
 
         # Ensure the speed we set was accepted
         result = self.vm.qmp('query-block-jobs')
@@ -470,8 +455,7 @@ class TestErrorHandling(iotests.QMPTestCase):
         os.remove(backing_img)
 
     def blockdev_add(self, **kwargs):
-        result = self.vm.qmp('blockdev-add', **kwargs)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', **kwargs)
 
     def add_block_nodes(self, base_debug=None, mid_debug=None, top_debug=None):
         self.blockdev_add(node_name='base-file', driver='file',
@@ -517,11 +501,9 @@ class TestErrorHandling(iotests.QMPTestCase):
                 completed = True
             elif ev['event'] == 'BLOCK_JOB_ERROR':
                 if error_pauses_job:
-                    result = self.vm.qmp('block-job-resume', device='job0')
-                    self.assert_qmp(result, 'return', {})
+                    self.vm.cmd('block-job-resume', device='job0')
             elif ev['event'] == 'BLOCK_JOB_READY':
-                result = self.vm.qmp('block-job-complete', device='job0')
-                self.assert_qmp(result, 'return', {})
+                self.vm.cmd('block-job-complete', device='job0')
             else:
                 self.fail("Unexpected event: %s" % ev)
             log.append(iotests.filter_qmp_event(ev))
@@ -584,11 +566,10 @@ class TestErrorHandling(iotests.QMPTestCase):
         self.add_block_nodes(top_debug=top_debug, mid_debug=mid_debug,
                              base_debug=base_debug)
 
-        result = self.vm.qmp('block-commit', job_id='job0', device='top-fmt',
-                             top_node='top-fmt' if active else 'mid-fmt',
-                             base_node='mid-fmt' if active else 'base-fmt',
-                             on_error=on_error)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit', job_id='job0', device='top-fmt',
+                    top_node='top-fmt' if active else 'mid-fmt',
+                    base_node='mid-fmt' if active else 'base-fmt',
+                    on_error=on_error)
 
     def testActiveReadErrorReport(self):
         self.prepare_and_start_job('report', top_event='read_aio')
@@ -761,10 +742,9 @@ class TestCommitWithFilters(iotests.QMPTestCase):
         self.vm = iotests.VM().add_device('virtio-scsi,id=vio-scsi')
         self.vm.launch()
 
-        result = self.vm.qmp('object-add', qom_type='throttle-group', id='tg')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('object-add', qom_type='throttle-group', id='tg')
 
-        result = self.vm.qmp('blockdev-add', **{
+        self.vm.cmd('blockdev-add', {
                 'node-name': 'top-filter',
                 'driver': 'throttle',
                 'throttle-group': 'tg',
@@ -806,7 +786,6 @@ class TestCommitWithFilters(iotests.QMPTestCase):
                     }
                 }
             })
-        self.assert_qmp(result, 'return', {})
 
     def tearDown(self):
         self.vm.shutdown()
@@ -823,12 +802,11 @@ class TestCommitWithFilters(iotests.QMPTestCase):
         return self.vm.node_info(node)['image']['filename']
 
     def test_filterless_commit(self):
-        result = self.vm.qmp('block-commit',
-                             job_id='commit',
-                             device='top-filter',
-                             top_node='cow-2',
-                             base_node='cow-1')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit',
+                    job_id='commit',
+                    device='top-filter',
+                    top_node='cow-2',
+                    base_node='cow-1')
         self.wait_until_completed(drive='commit')
 
         self.assertIsNotNone(self.vm.node_info('cow-3'))
@@ -839,12 +817,11 @@ class TestCommitWithFilters(iotests.QMPTestCase):
         self.pattern_files[2] = self.img1
 
     def test_commit_through_filter(self):
-        result = self.vm.qmp('block-commit',
-                             job_id='commit',
-                             device='top-filter',
-                             top_node='cow-1',
-                             base_node='cow-0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit',
+                    job_id='commit',
+                    device='top-filter',
+                    top_node='cow-1',
+                    base_node='cow-0')
         self.wait_until_completed(drive='commit')
 
         self.assertIsNotNone(self.vm.node_info('cow-2'))
@@ -859,9 +836,8 @@ class TestCommitWithFilters(iotests.QMPTestCase):
         # Add a device, so the commit job finds a parent it can change
         # to point to the base node (so we can test that top-filter is
         # dropped from the graph)
-        result = self.vm.qmp('device_add', id='drv0', driver='scsi-hd',
-                             bus='vio-scsi.0', drive='top-filter')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('device_add', id='drv0', driver='scsi-hd',
+                    bus='vio-scsi.0', drive='top-filter')
 
         # Try to release our reference to top-filter; that should not
         # work because drv0 uses it
@@ -869,16 +845,14 @@ class TestCommitWithFilters(iotests.QMPTestCase):
         self.assert_qmp(result, 'error/class', 'GenericError')
         self.assert_qmp(result, 'error/desc', 'Node top-filter is in use')
 
-        result = self.vm.qmp('block-commit',
-                             job_id='commit',
-                             device='top-filter',
-                             base_node='cow-2')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit',
+                    job_id='commit',
+                    device='top-filter',
+                    base_node='cow-2')
         self.complete_and_wait(drive='commit')
 
         # Try to release our reference to top-filter again
-        result = self.vm.qmp('blockdev-del', node_name='top-filter')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', node_name='top-filter')
 
         self.assertIsNone(self.vm.node_info('top-filter'))
         self.assertIsNone(self.vm.node_info('cow-3'))
@@ -893,12 +867,11 @@ class TestCommitWithFilters(iotests.QMPTestCase):
         self.pattern_files[3] = self.img2
 
     def test_filtered_active_commit_without_filter(self):
-        result = self.vm.qmp('block-commit',
-                             job_id='commit',
-                             device='top-filter',
-                             top_node='cow-3',
-                             base_node='cow-2')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit',
+                    job_id='commit',
+                    device='top-filter',
+                    top_node='cow-3',
+                    base_node='cow-2')
         self.complete_and_wait(drive='commit')
 
         self.assertIsNotNone(self.vm.node_info('top-filter'))
@@ -923,23 +896,22 @@ class TestCommitWithOverriddenBacking(iotests.QMPTestCase):
         self.vm.launch()
 
         # Use base_b instead of base_a as the backing of top
-        result = self.vm.qmp('blockdev-add', **{
-                                'node-name': 'top',
-                                'driver': iotests.imgfmt,
-                                'file': {
-                                    'driver': 'file',
-                                    'filename': self.img_top
-                                },
-                                'backing': {
-                                    'node-name': 'base',
-                                    'driver': iotests.imgfmt,
-                                    'file': {
-                                        'driver': 'file',
-                                        'filename': self.img_base_b
-                                    }
-                                }
-                            })
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', {
+            'node-name': 'top',
+            'driver': iotests.imgfmt,
+            'file': {
+                'driver': 'file',
+                'filename': self.img_top
+            },
+            'backing': {
+                'node-name': 'base',
+                'driver': iotests.imgfmt,
+                'file': {
+                    'driver': 'file',
+                    'filename': self.img_base_b
+                }
+            }
+        })
 
     def tearDown(self):
         self.vm.shutdown()
@@ -959,11 +931,10 @@ class TestCommitWithOverriddenBacking(iotests.QMPTestCase):
     def test_commit_to_b(self):
         # Try committing to base_b (which should work, since that is
         # actually top's backing image)
-        result = self.vm.qmp('block-commit',
-                             job_id='commit',
-                             device='top',
-                             base=self.img_base_b)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit',
+                    job_id='commit',
+                    device='top',
+                    base=self.img_base_b)
 
         self.vm.event_wait('BLOCK_JOB_READY')
         self.vm.qmp('block-job-complete', device='commit')
diff --git a/tests/qemu-iotests/041 b/tests/qemu-iotests/041
index 8429958bf0..4d2a699613 100755
--- a/tests/qemu-iotests/041
+++ b/tests/qemu-iotests/041
@@ -65,9 +65,8 @@ class TestSingleDrive(iotests.QMPTestCase):
     def test_complete(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp(self.qmp_cmd, device='drive0', sync='full',
-                             target=self.qmp_target)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(self.qmp_cmd, device='drive0', sync='full',
+                    target=self.qmp_target)
 
         self.complete_and_wait()
         result = self.vm.qmp('query-block')
@@ -79,9 +78,8 @@ class TestSingleDrive(iotests.QMPTestCase):
     def test_cancel(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp(self.qmp_cmd, device='drive0', sync='full',
-                             target=self.qmp_target)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(self.qmp_cmd, device='drive0', sync='full',
+                    target=self.qmp_target)
 
         self.cancel_and_wait(force=True)
         result = self.vm.qmp('query-block')
@@ -90,9 +88,8 @@ class TestSingleDrive(iotests.QMPTestCase):
     def test_cancel_after_ready(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp(self.qmp_cmd, device='drive0', sync='full',
-                             target=self.qmp_target)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(self.qmp_cmd, device='drive0', sync='full',
+                    target=self.qmp_target)
 
         self.wait_ready_and_cancel()
         result = self.vm.qmp('query-block')
@@ -104,9 +101,8 @@ class TestSingleDrive(iotests.QMPTestCase):
     def test_pause(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp(self.qmp_cmd, device='drive0', sync='full',
-                             target=self.qmp_target)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(self.qmp_cmd, device='drive0', sync='full',
+                    target=self.qmp_target)
 
         self.pause_job('drive0')
 
@@ -117,8 +113,7 @@ class TestSingleDrive(iotests.QMPTestCase):
         result = self.vm.qmp('query-block-jobs')
         self.assert_qmp(result, 'return[0]/offset', offset)
 
-        result = self.vm.qmp('block-job-resume', device='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-resume', device='drive0')
 
         self.complete_and_wait()
         self.vm.shutdown()
@@ -129,9 +124,8 @@ class TestSingleDrive(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
 
         # A small buffer is rounded up automatically
-        result = self.vm.qmp(self.qmp_cmd, device='drive0', sync='full',
-                             buf_size=4096, target=self.qmp_target)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(self.qmp_cmd, device='drive0', sync='full',
+                    buf_size=4096, target=self.qmp_target)
 
         self.complete_and_wait()
         result = self.vm.qmp('query-block')
@@ -145,9 +139,8 @@ class TestSingleDrive(iotests.QMPTestCase):
 
         qemu_img('create', '-f', iotests.imgfmt, '-o', 'cluster_size=%d,size=%d'
                         % (self.image_len, self.image_len), target_img)
-        result = self.vm.qmp(self.qmp_cmd, device='drive0', sync='full',
-                             buf_size=65536, mode='existing', target=self.qmp_target)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(self.qmp_cmd, device='drive0', sync='full',
+                    buf_size=65536, mode='existing', target=self.qmp_target)
 
         self.complete_and_wait()
         result = self.vm.qmp('query-block')
@@ -162,9 +155,8 @@ class TestSingleDrive(iotests.QMPTestCase):
         qemu_img('create', '-f', iotests.imgfmt, '-o', 'cluster_size=%d,backing_file=%s'
                         % (self.image_len, backing_img),
                  '-F', 'raw', target_img)
-        result = self.vm.qmp(self.qmp_cmd, device='drive0', sync='full',
-                             mode='existing', target=self.qmp_target)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(self.qmp_cmd, device='drive0', sync='full',
+                    mode='existing', target=self.qmp_target)
 
         self.complete_and_wait()
         result = self.vm.qmp('query-block')
@@ -178,9 +170,8 @@ class TestSingleDrive(iotests.QMPTestCase):
     def test_implicit_node(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp(self.qmp_cmd, device='drive0', sync='full',
-                             target=self.qmp_target)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(self.qmp_cmd, device='drive0', sync='full',
+                    target=self.qmp_target)
 
         result = self.vm.qmp('query-block')
         self.assert_qmp(result, 'return[0]/inserted/file', test_img)
@@ -236,8 +227,7 @@ class TestSingleBlockdev(TestSingleDrive):
         args = {'driver': iotests.imgfmt,
                 'node-name': self.qmp_target,
                 'file': { 'filename': target_img, 'driver': 'file' } }
-        result = self.vm.qmp("blockdev-add", **args)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd("blockdev-add", **args)
 
     def test_mirror_to_self(self):
         result = self.vm.qmp(self.qmp_cmd, job_id='job0',
@@ -254,10 +244,9 @@ class TestSingleBlockdev(TestSingleDrive):
             result = self.vm.qmp('block_resize', node_name=node, size=65536)
             self.assert_qmp(result, 'error/class', 'GenericError')
 
-        result = self.vm.qmp(self.qmp_cmd, job_id='job0', device='drive0',
-                             sync='full', target=self.qmp_target,
-                             auto_finalize=False, auto_dismiss=False)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(self.qmp_cmd, job_id='job0', device='drive0',
+                    sync='full', target=self.qmp_target,
+                    auto_finalize=False, auto_dismiss=False)
 
         result = self.vm.run_job('job0', auto_finalize=False,
                                  pre_finalize=pre_finalize)
@@ -270,14 +259,11 @@ class TestSingleBlockdev(TestSingleDrive):
         self.do_test_resize(None, self.qmp_target)
 
     def do_test_target_size(self, size):
-        result = self.vm.qmp('block_resize', node_name=self.qmp_target,
-                             size=size)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block_resize', node_name=self.qmp_target, size=size)
 
-        result = self.vm.qmp(self.qmp_cmd, job_id='job0',
-                             device='drive0', sync='full', auto_dismiss=False,
-                             target=self.qmp_target)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(self.qmp_cmd, job_id='job0',
+                    device='drive0', sync='full', auto_dismiss=False,
+                    target=self.qmp_target)
 
         result = self.vm.run_job('job0')
         self.assertEqual(result, 'Source and target image have different sizes')
@@ -337,9 +323,8 @@ class TestMirrorNoBacking(iotests.QMPTestCase):
 
         qemu_img('create', '-f', iotests.imgfmt,
                  '-o', 'backing_file=%s' % backing_img, '-F', 'raw', target_img)
-        result = self.vm.qmp('drive-mirror', device='drive0', sync='full',
-                             mode='existing', target=target_img)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', device='drive0', sync='full',
+                    mode='existing', target=target_img)
 
         self.complete_and_wait()
         result = self.vm.qmp('query-block')
@@ -353,9 +338,8 @@ class TestMirrorNoBacking(iotests.QMPTestCase):
 
         qemu_img('create', '-f', iotests.imgfmt,
                  '-o', 'backing_file=%s' % backing_img, '-F', 'raw', target_img)
-        result = self.vm.qmp('drive-mirror', device='drive0', sync='full',
-                             mode='existing', target=target_img)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', device='drive0', sync='full',
+                    mode='existing', target=target_img)
 
         self.wait_ready_and_cancel()
         result = self.vm.qmp('query-block')
@@ -374,9 +358,8 @@ class TestMirrorNoBacking(iotests.QMPTestCase):
                         % (TestMirrorNoBacking.image_len, target_backing_img),
                  '-F', iotests.imgfmt, target_img)
 
-        result = self.vm.qmp('drive-mirror', device='drive0', sync='full',
-                             mode='existing', target=target_img)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', device='drive0', sync='full',
+                    mode='existing', target=target_img)
 
         self.complete_and_wait()
         result = self.vm.qmp('query-block')
@@ -409,9 +392,8 @@ class TestMirrorResized(iotests.QMPTestCase):
     def test_complete_top(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('drive-mirror', device='drive0', sync='top',
-                             target=target_img)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', device='drive0', sync='top',
+                    target=target_img)
 
         self.complete_and_wait()
         result = self.vm.qmp('query-block')
@@ -423,9 +405,8 @@ class TestMirrorResized(iotests.QMPTestCase):
     def test_complete_full(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('drive-mirror', device='drive0', sync='full',
-                             target=target_img)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', device='drive0', sync='full',
+                    target=target_img)
 
         self.complete_and_wait()
         result = self.vm.qmp('query-block')
@@ -488,9 +469,8 @@ new_state = "1"
     def test_report_read(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('drive-mirror', device='drive0', sync='full',
-                             target=target_img)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', device='drive0', sync='full',
+                    target=target_img)
 
         completed = False
         error = False
@@ -516,9 +496,8 @@ new_state = "1"
     def test_ignore_read(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('drive-mirror', device='drive0', sync='full',
-                             target=target_img, on_source_error='ignore')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', device='drive0', sync='full',
+                    target=target_img, on_source_error='ignore')
 
         event = self.vm.get_qmp_event(wait=True)
         while event['event'] == 'JOB_STATUS_CHANGE':
@@ -541,10 +520,9 @@ new_state = "1"
         qemu_img('create', '-f', iotests.imgfmt,
                  '-ocluster_size=131072,backing_file=%s' %(backing_img),
                  '-F', 'raw', target_img)
-        result = self.vm.qmp('drive-mirror', device='drive0', sync='top',
-                             on_source_error='ignore',
-                             mode='existing', target=target_img)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', device='drive0', sync='top',
+                    on_source_error='ignore',
+                    mode='existing', target=target_img)
 
         event = self.vm.get_qmp_event(wait=True)
         while event['event'] == 'JOB_STATUS_CHANGE':
@@ -568,9 +546,8 @@ new_state = "1"
     def test_stop_read(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('drive-mirror', device='drive0', sync='full',
-                             target=target_img, on_source_error='stop')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', device='drive0', sync='full',
+                    target=target_img, on_source_error='stop')
 
         error = False
         ready = False
@@ -590,8 +567,7 @@ new_state = "1"
                     self.assert_qmp(result, 'return[0]/status', 'paused')
                     self.assert_qmp(result, 'return[0]/io-status', 'failed')
 
-                    result = self.vm.qmp('block-job-resume', device='drive0')
-                    self.assert_qmp(result, 'return', {})
+                    self.vm.cmd('block-job-resume', device='drive0')
                     error = True
                 elif event['event'] == 'BLOCK_JOB_READY':
                     self.assertTrue(error, 'job completed unexpectedly')
@@ -656,9 +632,8 @@ new_state = "1"
     def test_report_write(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('drive-mirror', device='drive0', sync='full',
-                             mode='existing', target=self.target_img)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', device='drive0', sync='full',
+                    mode='existing', target=self.target_img)
 
         completed = False
         error = False
@@ -682,10 +657,9 @@ new_state = "1"
     def test_ignore_write(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('drive-mirror', device='drive0', sync='full',
-                             mode='existing', target=self.target_img,
-                             on_target_error='ignore')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', device='drive0', sync='full',
+                    mode='existing', target=self.target_img,
+                    on_target_error='ignore')
 
         event = self.vm.event_wait(name='BLOCK_JOB_ERROR')
         self.assertEqual(event['event'], 'BLOCK_JOB_ERROR')
@@ -698,10 +672,9 @@ new_state = "1"
     def test_stop_write(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('drive-mirror', device='drive0', sync='full',
-                             mode='existing', target=self.target_img,
-                             on_target_error='stop')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', device='drive0', sync='full',
+                    mode='existing', target=self.target_img,
+                    on_target_error='stop')
 
         error = False
         ready = False
@@ -721,8 +694,7 @@ new_state = "1"
                     self.assert_qmp(result, 'return[0]/status', 'paused')
                     self.assert_qmp(result, 'return[0]/io-status', 'failed')
 
-                    result = self.vm.qmp('block-job-resume', device='drive0')
-                    self.assert_qmp(result, 'return', {})
+                    self.vm.cmd('block-job-resume', device='drive0')
 
                     result = self.vm.qmp('query-block-jobs')
                     self.assertIn(result['return'][0]['status'], ['running', 'ready'])
@@ -755,17 +727,15 @@ class TestSetSpeed(iotests.QMPTestCase):
     def test_set_speed(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('drive-mirror', device='drive0', sync='full',
-                             target=target_img)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', device='drive0', sync='full',
+                    target=target_img)
 
         # Default speed is 0
         result = self.vm.qmp('query-block-jobs')
         self.assert_qmp(result, 'return[0]/device', 'drive0')
         self.assert_qmp(result, 'return[0]/speed', 0)
 
-        result = self.vm.qmp('block-job-set-speed', device='drive0', speed=8 * 1024 * 1024)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-set-speed', device='drive0', speed=8 * 1024 * 1024)
 
         # Ensure the speed we set was accepted
         result = self.vm.qmp('query-block-jobs')
@@ -775,9 +745,8 @@ class TestSetSpeed(iotests.QMPTestCase):
         self.wait_ready_and_cancel()
 
         # Check setting speed in drive-mirror works
-        result = self.vm.qmp('drive-mirror', device='drive0', sync='full',
-                             target=target_img, speed=4*1024*1024)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', device='drive0', sync='full',
+                    target=target_img, speed=4*1024*1024)
 
         result = self.vm.qmp('query-block-jobs')
         self.assert_qmp(result, 'return[0]/device', 'drive0')
@@ -794,9 +763,8 @@ class TestSetSpeed(iotests.QMPTestCase):
 
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('drive-mirror', device='drive0', sync='full',
-                             target=target_img)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', device='drive0', sync='full',
+                    target=target_img)
 
         result = self.vm.qmp('block-job-set-speed', device='drive0', speed=-1)
         self.assert_qmp(result, 'error/class', 'GenericError')
@@ -811,13 +779,12 @@ class TestUnbackedSource(iotests.QMPTestCase):
                  str(TestUnbackedSource.image_len))
         self.vm = iotests.VM()
         self.vm.launch()
-        result = self.vm.qmp('blockdev-add', node_name='drive0',
-                             driver=iotests.imgfmt,
-                             file={
-                                 'driver': 'file',
-                                 'filename': test_img,
-                             })
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', node_name='drive0',
+                    driver=iotests.imgfmt,
+                    file={
+                        'driver': 'file',
+                        'filename': test_img,
+                    })
 
     def tearDown(self):
         self.vm.shutdown()
@@ -826,28 +793,25 @@ class TestUnbackedSource(iotests.QMPTestCase):
 
     def test_absolute_paths_full(self):
         self.assert_no_active_block_jobs()
-        result = self.vm.qmp('drive-mirror', job_id='drive0', device='drive0',
-                             sync='full', target=target_img,
-                             mode='absolute-paths')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', job_id='drive0', device='drive0',
+                    sync='full', target=target_img,
+                    mode='absolute-paths')
         self.complete_and_wait()
         self.assert_no_active_block_jobs()
 
     def test_absolute_paths_top(self):
         self.assert_no_active_block_jobs()
-        result = self.vm.qmp('drive-mirror', job_id='drive0', device='drive0',
-                             sync='top', target=target_img,
-                             mode='absolute-paths')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', job_id='drive0', device='drive0',
+                    sync='top', target=target_img,
+                    mode='absolute-paths')
         self.complete_and_wait()
         self.assert_no_active_block_jobs()
 
     def test_absolute_paths_none(self):
         self.assert_no_active_block_jobs()
-        result = self.vm.qmp('drive-mirror', job_id='drive0', device='drive0',
-                             sync='none', target=target_img,
-                             mode='absolute-paths')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', job_id='drive0', device='drive0',
+                    sync='none', target=target_img,
+                    mode='absolute-paths')
         self.complete_and_wait()
         self.assert_no_active_block_jobs()
 
@@ -857,14 +821,12 @@ class TestUnbackedSource(iotests.QMPTestCase):
         qemu_io('-c', 'write -P 42 0 64k', target_img)
 
         self.assert_no_active_block_jobs()
-        result = self.vm.qmp('drive-mirror', job_id='drive0', device='drive0',
-                             sync='full', target=target_img, mode='existing')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', job_id='drive0', device='drive0',
+                    sync='full', target=target_img, mode='existing')
         self.complete_and_wait()
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('blockdev-del', node_name='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', node_name='drive0')
 
         self.assertTrue(iotests.compare_images(test_img, target_img),
                         'target image does not match source after mirroring')
@@ -874,26 +836,22 @@ class TestUnbackedSource(iotests.QMPTestCase):
                  str(self.image_len))
         qemu_io('-c', 'write -P 42 0 64k', target_img)
 
-        result = self.vm.qmp('blockdev-add', node_name='target',
-                             driver=iotests.imgfmt,
-                             file={
-                                 'driver': 'file',
-                                 'filename': target_img,
-                             })
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', node_name='target',
+                    driver=iotests.imgfmt,
+                    file={
+                        'driver': 'file',
+                        'filename': target_img,
+                    })
 
         self.assert_no_active_block_jobs()
-        result = self.vm.qmp('blockdev-mirror', job_id='drive0', device='drive0',
-                             sync='full', target='target')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-mirror', job_id='drive0', device='drive0',
+                    sync='full', target='target')
         self.complete_and_wait()
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('blockdev-del', node_name='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', node_name='drive0')
 
-        result = self.vm.qmp('blockdev-del', node_name='target')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', node_name='target')
 
         self.assertTrue(iotests.compare_images(test_img, target_img),
                         'target image does not match source after mirroring')
@@ -918,10 +876,9 @@ class TestGranularity(iotests.QMPTestCase):
 
     def test_granularity(self):
         self.assert_no_active_block_jobs()
-        result = self.vm.qmp('drive-mirror', device='drive0',
-                             sync='full', target=target_img,
-                             mode='absolute-paths', granularity=8192)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', device='drive0',
+                    sync='full', target=target_img,
+                    mode='absolute-paths', granularity=8192)
 
         event = self.vm.get_qmp_event(wait=60.0)
         while event['event'] == 'JOB_STATUS_CHANGE':
@@ -963,8 +920,7 @@ class TestRepairQuorum(iotests.QMPTestCase):
         #assemble the quorum block device from the individual files
         args = { "driver": "quorum", "node-name": "quorum0",
                  "vote-threshold": 2, "children": [ "img0", "img1", "img2" ] }
-        result = self.vm.qmp("blockdev-add", **args)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd("blockdev-add", **args)
 
 
     def tearDown(self):
@@ -978,10 +934,9 @@ class TestRepairQuorum(iotests.QMPTestCase):
                 pass
 
     def test_complete(self):
-        result = self.vm.qmp('drive-mirror', job_id='job0', device='quorum0',
-                             sync='full', node_name="repair0", replaces="img1",
-                             target=quorum_repair_img, format=iotests.imgfmt)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', job_id='job0', device='quorum0',
+                    sync='full', node_name="repair0", replaces="img1",
+                    target=quorum_repair_img, format=iotests.imgfmt)
 
         self.complete_and_wait(drive="job0")
         self.assert_has_block_node("repair0", quorum_repair_img)
@@ -991,10 +946,9 @@ class TestRepairQuorum(iotests.QMPTestCase):
                         'target image does not match source after mirroring')
 
     def test_cancel(self):
-        result = self.vm.qmp('drive-mirror', job_id='job0', device='quorum0',
-                             sync='full', node_name="repair0", replaces="img1",
-                             target=quorum_repair_img, format=iotests.imgfmt)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', job_id='job0', device='quorum0',
+                    sync='full', node_name="repair0", replaces="img1",
+                    target=quorum_repair_img, format=iotests.imgfmt)
 
         self.cancel_and_wait(drive="job0", force=True)
         # here we check that the last registered quorum file has not been
@@ -1002,10 +956,9 @@ class TestRepairQuorum(iotests.QMPTestCase):
         self.assert_has_block_node(None, quorum_img3)
 
     def test_cancel_after_ready(self):
-        result = self.vm.qmp('drive-mirror', job_id='job0', device='quorum0',
-                             sync='full', node_name="repair0", replaces="img1",
-                             target=quorum_repair_img, format=iotests.imgfmt)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', job_id='job0', device='quorum0',
+                    sync='full', node_name="repair0", replaces="img1",
+                    target=quorum_repair_img, format=iotests.imgfmt)
 
         self.wait_ready_and_cancel(drive="job0")
         # here we check that the last registered quorum file has not been
@@ -1016,10 +969,9 @@ class TestRepairQuorum(iotests.QMPTestCase):
                         'target image does not match source after mirroring')
 
     def test_pause(self):
-        result = self.vm.qmp('drive-mirror', job_id='job0', device='quorum0',
-                             sync='full', node_name="repair0", replaces="img1",
-                             target=quorum_repair_img, format=iotests.imgfmt)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', job_id='job0', device='quorum0',
+                    sync='full', node_name="repair0", replaces="img1",
+                    target=quorum_repair_img, format=iotests.imgfmt)
 
         self.pause_job('job0')
 
@@ -1030,8 +982,7 @@ class TestRepairQuorum(iotests.QMPTestCase):
         result = self.vm.qmp('query-block-jobs')
         self.assert_qmp(result, 'return[0]/offset', offset)
 
-        result = self.vm.qmp('block-job-resume', device='job0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-resume', device='job0')
 
         self.complete_and_wait(drive="job0")
         self.vm.shutdown()
@@ -1093,10 +1044,9 @@ class TestRepairQuorum(iotests.QMPTestCase):
                              target=quorum_repair_img, format=iotests.imgfmt)
         self.assert_qmp(result, 'error/class', 'GenericError')
 
-        result = self.vm.qmp('drive-mirror', job_id='job0', device='quorum0',
-                             sync='full', node_name='repair0', replaces="snap1",
-                             target=quorum_repair_img, format=iotests.imgfmt)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', job_id='job0', device='quorum0',
+                    sync='full', node_name='repair0', replaces="snap1",
+                    target=quorum_repair_img, format=iotests.imgfmt)
 
         self.complete_and_wait('job0')
         self.assert_has_block_node("repair0", quorum_repair_img)
@@ -1107,15 +1057,13 @@ class TestRepairQuorum(iotests.QMPTestCase):
         Check that we cannot replace a Quorum child when it has other
         parents.
         """
-        result = self.vm.qmp('nbd-server-start',
-                             addr={
-                                 'type': 'unix',
-                                 'data': {'path': nbd_sock_path}
-                             })
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('nbd-server-start',
+                    addr={
+                        'type': 'unix',
+                        'data': {'path': nbd_sock_path}
+                    })
 
-        result = self.vm.qmp('nbd-server-add', device='img1')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('nbd-server-add', device='img1')
 
         result = self.vm.qmp('drive-mirror', job_id='mirror', device='quorum0',
                              sync='full', node_name='repair0', replaces='img1',
@@ -1130,20 +1078,17 @@ class TestRepairQuorum(iotests.QMPTestCase):
         The same as test_with_other_parent(), but add the NBD server
         only when the mirror job is already running.
         """
-        result = self.vm.qmp('nbd-server-start',
-                             addr={
-                                 'type': 'unix',
-                                 'data': {'path': nbd_sock_path}
-                             })
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('nbd-server-start',
+                    addr={
+                        'type': 'unix',
+                        'data': {'path': nbd_sock_path}
+                    })
 
-        result = self.vm.qmp('drive-mirror', job_id='mirror', device='quorum0',
-                             sync='full', node_name='repair0', replaces='img1',
-                             target=quorum_repair_img, format=iotests.imgfmt)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', job_id='mirror', device='quorum0',
+                    sync='full', node_name='repair0', replaces='img1',
+                    target=quorum_repair_img, format=iotests.imgfmt)
 
-        result = self.vm.qmp('nbd-server-add', device='img1')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('nbd-server-add', device='img1')
 
         # The full error message goes to stderr, we will check it later
         self.complete_and_wait('mirror',
@@ -1199,9 +1144,8 @@ class TestOrphanedSource(iotests.QMPTestCase):
     def test_success(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('blockdev-mirror', job_id='job', device='src',
-                             sync='full', target='dest')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-mirror', job_id='job', device='src',
+                    sync='full', target='dest')
 
         self.complete_and_wait('job')
 
@@ -1217,27 +1161,24 @@ class TestOrphanedSource(iotests.QMPTestCase):
 
         # Unshare consistent-read on the target
         # (The mirror job does not care)
-        result = self.vm.qmp('blockdev-add',
-                             driver='blkdebug',
-                             node_name='dest-perm',
-                             image='dest',
-                             unshare_child_perms=['consistent-read'])
-        self.assert_qmp(result, 'return', {})
-
-        result = self.vm.qmp('blockdev-mirror', job_id='job', device='src',
-                             sync='full', target='dest',
-                             filter_node_name='mirror-filter')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add',
+                    driver='blkdebug',
+                    node_name='dest-perm',
+                    image='dest',
+                    unshare_child_perms=['consistent-read'])
+
+        self.vm.cmd('blockdev-mirror', job_id='job', device='src',
+                    sync='full', target='dest',
+                    filter_node_name='mirror-filter')
 
         # Require consistent-read on the source
         # (We can only add this node once the job has started, or it
         # will complain that it does not want to run on non-root nodes)
-        result = self.vm.qmp('blockdev-add',
-                             driver='blkdebug',
-                             node_name='src-perm',
-                             image='src',
-                             take_child_perms=['consistent-read'])
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add',
+                    driver='blkdebug',
+                    node_name='src-perm',
+                    image='src',
+                    take_child_perms=['consistent-read'])
 
         # While completing, mirror will attempt to replace src by
         # dest, which must fail because src-perm requires
@@ -1277,26 +1218,22 @@ class TestReplaces(iotests.QMPTestCase):
         """
         Check that we can replace filter nodes.
         """
-        result = self.vm.qmp('blockdev-add', **{
-                                 'driver': 'copy-on-read',
-                                 'node-name': 'filter0',
-                                 'file': {
-                                     'driver': 'copy-on-read',
-                                     'node-name': 'filter1',
-                                     'file': {
-                                         'driver': 'null-co'
-                                     }
-                                 }
-                             })
-        self.assert_qmp(result, 'return', {})
-
-        result = self.vm.qmp('blockdev-add',
-                             node_name='target', driver='null-co')
-        self.assert_qmp(result, 'return', {})
-
-        result = self.vm.qmp('blockdev-mirror', job_id='mirror', device='filter0',
-                             target='target', sync='full', replaces='filter1')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', {
+            'driver': 'copy-on-read',
+            'node-name': 'filter0',
+            'file': {
+                'driver': 'copy-on-read',
+                'node-name': 'filter1',
+                'file': {
+                    'driver': 'null-co'
+                }
+            }
+        })
+
+        self.vm.cmd('blockdev-add', node_name='target', driver='null-co')
+
+        self.vm.cmd('blockdev-mirror', job_id='mirror', device='filter0',
+                    target='target', sync='full', replaces='filter1')
 
         self.complete_and_wait('mirror')
 
@@ -1318,16 +1255,15 @@ class TestFilters(iotests.QMPTestCase):
         self.vm = iotests.VM().add_device('virtio-scsi,id=vio-scsi')
         self.vm.launch()
 
-        result = self.vm.qmp('blockdev-add', **{
-                                'node-name': 'target',
-                                'driver': iotests.imgfmt,
-                                'file': {
-                                    'driver': 'file',
-                                    'filename': target_img
-                                },
-                                'backing': None
-                            })
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', {
+            'node-name': 'target',
+            'driver': iotests.imgfmt,
+            'file': {
+                'driver': 'file',
+                'filename': target_img
+            },
+            'backing': None
+        })
 
         self.filterless_chain = {
                 'node-name': 'source',
@@ -1354,19 +1290,17 @@ class TestFilters(iotests.QMPTestCase):
         os.remove(backing_img)
 
     def test_cor(self):
-        result = self.vm.qmp('blockdev-add', **{
-                                'node-name': 'filter',
-                                'driver': 'copy-on-read',
-                                'file': self.filterless_chain
-                            })
-        self.assert_qmp(result, 'return', {})
-
-        result = self.vm.qmp('blockdev-mirror',
-                             job_id='mirror',
-                             device='filter',
-                             target='target',
-                             sync='top')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', {
+            'node-name': 'filter',
+            'driver': 'copy-on-read',
+            'file': self.filterless_chain
+        })
+
+        self.vm.cmd('blockdev-mirror',
+                    job_id='mirror',
+                    device='filter',
+                    target='target',
+                    sync='top')
 
         self.complete_and_wait('mirror')
 
@@ -1383,23 +1317,20 @@ class TestFilters(iotests.QMPTestCase):
         assert target_map[1]['depth'] == 0
 
     def test_implicit_mirror_filter(self):
-        result = self.vm.qmp('blockdev-add', **self.filterless_chain)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', **self.filterless_chain)
 
         # We need this so we can query from above the mirror node
-        result = self.vm.qmp('device_add',
-                             driver='scsi-hd',
-                             id='virtio',
-                             bus='vio-scsi.0',
-                             drive='source')
-        self.assert_qmp(result, 'return', {})
-
-        result = self.vm.qmp('blockdev-mirror',
-                             job_id='mirror',
-                             device='source',
-                             target='target',
-                             sync='top')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('device_add',
+                    driver='scsi-hd',
+                    id='virtio',
+                    bus='vio-scsi.0',
+                    drive='source')
+
+        self.vm.cmd('blockdev-mirror',
+                    job_id='mirror',
+                    device='source',
+                    target='target',
+                    sync='top')
 
         # The mirror filter is now an implicit node, so it should be
         # invisible when querying the backing chain
@@ -1417,24 +1348,21 @@ class TestFilters(iotests.QMPTestCase):
     def test_explicit_mirror_filter(self):
         # Same test as above, but this time we give the mirror filter
         # a node-name so it will not be invisible
-        result = self.vm.qmp('blockdev-add', **self.filterless_chain)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', **self.filterless_chain)
 
         # We need this so we can query from above the mirror node
-        result = self.vm.qmp('device_add',
-                             driver='scsi-hd',
-                             id='virtio',
-                             bus='vio-scsi.0',
-                             drive='source')
-        self.assert_qmp(result, 'return', {})
-
-        result = self.vm.qmp('blockdev-mirror',
-                             job_id='mirror',
-                             device='source',
-                             target='target',
-                             sync='top',
-                             filter_node_name='mirror-filter')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('device_add',
+                    driver='scsi-hd',
+                    id='virtio',
+                    bus='vio-scsi.0',
+                    drive='source')
+
+        self.vm.cmd('blockdev-mirror',
+                    job_id='mirror',
+                    device='source',
+                    target='target',
+                    sync='top',
+                    filter_node_name='mirror-filter')
 
         # With a node-name given to it, the mirror filter should now
         # be visible
diff --git a/tests/qemu-iotests/045 b/tests/qemu-iotests/045
index 45eb239baa..a341f21cd7 100755
--- a/tests/qemu-iotests/045
+++ b/tests/qemu-iotests/045
@@ -77,8 +77,7 @@ class TestFdSets(iotests.QMPTestCase):
         self.vm.shutdown()
 
     def test_remove_fdset(self):
-        result = self.vm.qmp('remove-fd', fdset_id=2)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('remove-fd', fdset_id=2)
         result = self.vm.qmp('query-fdsets')
         self.assert_qmp(result, 'return[0]/fdset-id', 1)
         self.assert_qmp(result, 'return[1]/fdset-id', 0)
@@ -90,8 +89,7 @@ class TestFdSets(iotests.QMPTestCase):
     def test_remove_fd(self):
         result = self.vm.qmp('query-fdsets')
         fd_image3 = result['return'][0]['fds'][0]['fd']
-        result = self.vm.qmp('remove-fd', fdset_id=2, fd=fd_image3)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('remove-fd', fdset_id=2, fd=fd_image3)
         result = self.vm.qmp('query-fdsets')
         self.assert_qmp(result, 'return[0]/fdset-id', 2)
         self.assert_qmp(result, 'return[1]/fdset-id', 1)
@@ -151,8 +149,7 @@ class TestSCMFd(iotests.QMPTestCase):
 
     def test_getfd(self):
         self._send_fd_by_SCM()
-        result = self.vm.qmp('getfd', fdname='image0:r')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('getfd', fdname='image0:r')
 
     def test_getfd_invalid_fdname(self):
         self._send_fd_by_SCM()
@@ -163,10 +160,8 @@ class TestSCMFd(iotests.QMPTestCase):
 
     def test_closefd(self):
         self._send_fd_by_SCM()
-        result = self.vm.qmp('getfd', fdname='image0:r')
-        self.assert_qmp(result, 'return', {})
-        result = self.vm.qmp('closefd', fdname='image0:r')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('getfd', fdname='image0:r')
+        self.vm.cmd('closefd', fdname='image0:r')
 
     def test_closefd_fd_not_found(self):
         fdname = 'image0:r'
diff --git a/tests/qemu-iotests/055 b/tests/qemu-iotests/055
index 5d6b607051..378f2737fd 100755
--- a/tests/qemu-iotests/055
+++ b/tests/qemu-iotests/055
@@ -69,8 +69,7 @@ class TestSingleDrive(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
 
         self.vm.pause_drive('drive0')
-        result = self.vm.qmp(cmd, device='drive0', target=target, sync='full')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(cmd, device='drive0', target=target, sync='full')
 
         event = self.cancel_and_wait(resume=True)
         self.assert_qmp(event, 'data/type', 'backup')
@@ -85,9 +84,7 @@ class TestSingleDrive(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
 
         self.vm.pause_drive('drive0')
-        result = self.vm.qmp(cmd, device='drive0',
-                             target=target, sync='full')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(cmd, device='drive0', target=target, sync='full')
 
         self.pause_job('drive0', wait=False)
         self.vm.resume_drive('drive0')
@@ -100,8 +97,7 @@ class TestSingleDrive(iotests.QMPTestCase):
         result = self.vm.qmp('query-block-jobs')
         self.assert_qmp(result, 'return[0]/offset', offset)
 
-        result = self.vm.qmp('block-job-resume', device='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-resume', device='drive0')
 
         self.wait_until_completed()
 
@@ -123,10 +119,9 @@ class TestSingleDrive(iotests.QMPTestCase):
             result = self.vm.qmp('block_resize', node_name=node, size=65536)
             self.assert_qmp(result, 'error/class', 'GenericError')
 
-        result = self.vm.qmp('blockdev-backup', job_id='job0', device='drive0',
-                             target='drive1', sync='full', auto_finalize=False,
-                             auto_dismiss=False)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-backup', job_id='job0', device='drive0',
+                    target='drive1', sync='full', auto_finalize=False,
+                    auto_dismiss=False)
 
         self.vm.run_job('job0', auto_finalize=False, pre_finalize=pre_finalize)
 
@@ -137,8 +132,7 @@ class TestSingleDrive(iotests.QMPTestCase):
         self.do_test_resize_blockdev_backup('drive1', 'target')
 
     def do_test_target_size(self, size):
-        result = self.vm.qmp('block_resize', device='drive1', size=size)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block_resize', device='drive1', size=size)
 
         result = self.vm.qmp('blockdev-backup', job_id='job0', device='drive0',
                              target='drive1', sync='full')
@@ -219,16 +213,14 @@ class TestSetSpeed(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
 
         self.vm.pause_drive('drive0')
-        result = self.vm.qmp(cmd, device='drive0', target=target, sync='full')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(cmd, device='drive0', target=target, sync='full')
 
         # Default speed is 0
         result = self.vm.qmp('query-block-jobs')
         self.assert_qmp(result, 'return[0]/device', 'drive0')
         self.assert_qmp(result, 'return[0]/speed', 0)
 
-        result = self.vm.qmp('block-job-set-speed', device='drive0', speed=8 * 1024 * 1024)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-set-speed', device='drive0', speed=8 * 1024 * 1024)
 
         # Ensure the speed we set was accepted
         result = self.vm.qmp('query-block-jobs')
@@ -240,9 +232,8 @@ class TestSetSpeed(iotests.QMPTestCase):
 
         # Check setting speed option works
         self.vm.pause_drive('drive0')
-        result = self.vm.qmp(cmd, device='drive0',
-                             target=target, sync='full', speed=4*1024*1024)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(cmd, device='drive0',
+                    target=target, sync='full', speed=4*1024*1024)
 
         result = self.vm.qmp('query-block-jobs')
         self.assert_qmp(result, 'return[0]/device', 'drive0')
@@ -267,9 +258,8 @@ class TestSetSpeed(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
 
         self.vm.pause_drive('drive0')
-        result = self.vm.qmp(cmd, device='drive0',
-                             target=target, sync='full')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(cmd, device='drive0',
+                    target=target, sync='full')
 
         result = self.vm.qmp('block-job-set-speed', device='drive0', speed=-1)
         self.assert_qmp(result, 'error/class', 'GenericError')
@@ -306,7 +296,7 @@ class TestSingleTransaction(iotests.QMPTestCase):
     def do_test_cancel(self, cmd, target):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('transaction', actions=[{
+        self.vm.cmd('transaction', actions=[{
                 'type': cmd,
                 'data': { 'device': 'drive0',
                           'target': target,
@@ -315,8 +305,6 @@ class TestSingleTransaction(iotests.QMPTestCase):
             }
         ])
 
-        self.assert_qmp(result, 'return', {})
-
         event = self.cancel_and_wait()
         self.assert_qmp(event, 'data/type', 'backup')
 
@@ -329,7 +317,7 @@ class TestSingleTransaction(iotests.QMPTestCase):
     def do_test_pause(self, cmd, target, image):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('transaction', actions=[{
+        self.vm.cmd('transaction', actions=[{
                 'type': cmd,
                 'data': { 'device': 'drive0',
                           'target': target,
@@ -337,12 +325,10 @@ class TestSingleTransaction(iotests.QMPTestCase):
                           'speed': 64 * 1024 },
             }
         ])
-        self.assert_qmp(result, 'return', {})
 
         self.pause_job('drive0', wait=False)
 
-        result = self.vm.qmp('block-job-set-speed', device='drive0', speed=0)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-set-speed', device='drive0', speed=0)
 
         self.pause_wait('drive0')
 
@@ -353,8 +339,7 @@ class TestSingleTransaction(iotests.QMPTestCase):
         result = self.vm.qmp('query-block-jobs')
         self.assert_qmp(result, 'return[0]/offset', offset)
 
-        result = self.vm.qmp('block-job-resume', device='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-resume', device='drive0')
 
         self.wait_until_completed()
 
@@ -519,8 +504,7 @@ class TestCompressedToQcow2(iotests.QMPTestCase):
 
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp(cmd, device='drive0', sync='full', compress=True, **args)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(cmd, device='drive0', sync='full', compress=True, **args)
 
         self.wait_until_completed()
 
@@ -545,8 +529,7 @@ class TestCompressedToQcow2(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
 
         self.vm.pause_drive('drive0')
-        result = self.vm.qmp(cmd, device='drive0', sync='full', compress=True, **args)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(cmd, device='drive0', sync='full', compress=True, **args)
 
         event = self.cancel_and_wait(resume=True)
         self.assert_qmp(event, 'data/type', 'backup')
@@ -568,8 +551,7 @@ class TestCompressedToQcow2(iotests.QMPTestCase):
         self.assert_no_active_block_jobs()
 
         self.vm.pause_drive('drive0')
-        result = self.vm.qmp(cmd, device='drive0', sync='full', compress=True, **args)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(cmd, device='drive0', sync='full', compress=True, **args)
 
         self.pause_job('drive0', wait=False)
         self.vm.resume_drive('drive0')
@@ -582,8 +564,7 @@ class TestCompressedToQcow2(iotests.QMPTestCase):
         result = self.vm.qmp('query-block-jobs')
         self.assert_qmp(result, 'return[0]/offset', offset)
 
-        result = self.vm.qmp('block-job-resume', device='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-resume', device='drive0')
 
         self.wait_until_completed()
 
diff --git a/tests/qemu-iotests/056 b/tests/qemu-iotests/056
index b459a3f1e8..34f08b872d 100755
--- a/tests/qemu-iotests/056
+++ b/tests/qemu-iotests/056
@@ -75,9 +75,8 @@ class TestSyncModesNoneAndTop(iotests.QMPTestCase):
 
     def test_complete_top(self):
         self.assert_no_active_block_jobs()
-        result = self.vm.qmp('drive-backup', device='drive0', sync='top',
-                             format=iotests.imgfmt, target=target_img)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-backup', device='drive0', sync='top',
+                    format=iotests.imgfmt, target=target_img)
 
         self.wait_until_completed(check_offset=False)
 
@@ -89,9 +88,8 @@ class TestSyncModesNoneAndTop(iotests.QMPTestCase):
     def test_cancel_sync_none(self):
         self.assert_no_active_block_jobs()
 
-        result = self.vm.qmp('drive-backup', device='drive0',
-                             sync='none', target=target_img)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-backup', device='drive0',
+                    sync='none', target=target_img)
         time.sleep(1)
         self.vm.hmp_qemu_io('drive0', 'write -P0x5e 0 512')
         self.vm.hmp_qemu_io('drive0', 'aio_flush')
@@ -115,18 +113,15 @@ class TestBeforeWriteNotifier(iotests.QMPTestCase):
 
     def test_before_write_notifier(self):
         self.vm.pause_drive("drive0")
-        result = self.vm.qmp('drive-backup', device='drive0',
-                             sync='full', target=target_img,
-                             format="file", speed=1)
-        self.assert_qmp(result, 'return', {})
-        result = self.vm.qmp('block-job-pause', device="drive0")
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-backup', device='drive0',
+                    sync='full', target=target_img,
+                    format="file", speed=1)
+        self.vm.cmd('block-job-pause', device="drive0")
         # Speed is low enough that this must be an uncopied range, which will
         # trigger the before write notifier
         self.vm.hmp_qemu_io('drive0', 'aio_write -P 1 512512 512')
         self.vm.resume_drive("drive0")
-        result = self.vm.qmp('block-job-resume', device="drive0")
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-resume', device="drive0")
         event = self.cancel_and_wait()
         self.assert_qmp(event, 'data/type', 'backup')
 
diff --git a/tests/qemu-iotests/093 b/tests/qemu-iotests/093
index 93274dc8cb..bf7763c8f6 100755
--- a/tests/qemu-iotests/093
+++ b/tests/qemu-iotests/093
@@ -55,8 +55,7 @@ class ThrottleTestCase(iotests.QMPTestCase):
         # Set the I/O throttling parameters to all drives
         for i in range(0, ndrives):
             params['device'] = 'drive%d' % i
-            result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **params)
-            self.assert_qmp(result, 'return', {})
+            self.vm.cmd("block_set_io_throttle", conv_keys=False, **params)
 
     def do_test_throttle(self, ndrives, seconds, params, first_drive = 0):
         def check_limit(limit, num):
@@ -253,8 +252,7 @@ class ThrottleTestCase(iotests.QMPTestCase):
         # drive1 remains in the group with a throttled request.
         params['bps_rd'] = 0
         params['device'] = 'drive0'
-        result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **params)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd("block_set_io_throttle", conv_keys=False, **params)
 
         # Removing the I/O limits from drive0 drains its two pending requests.
         # The read request in drive1 is still throttled.
@@ -286,8 +284,7 @@ class ThrottleTestGroupNames(iotests.QMPTestCase):
 
     def set_io_throttle(self, device, params):
         params["device"] = device
-        result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **params)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd("block_set_io_throttle", conv_keys=False, **params)
 
     def verify_name(self, device, name):
         result = self.vm.qmp("query-block")
@@ -379,23 +376,18 @@ class ThrottleTestRemovableMedia(iotests.QMPTestCase):
 
     def test_removable_media(self):
         # Add a couple of dummy nodes named cd0 and cd1
-        result = self.vm.qmp("blockdev-add", driver="null-co",
-                             read_zeroes=True, node_name="cd0")
-        self.assert_qmp(result, 'return', {})
-        result = self.vm.qmp("blockdev-add", driver="null-co",
-                             read_zeroes=True, node_name="cd1")
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd("blockdev-add", driver="null-co",
+                    read_zeroes=True, node_name="cd0")
+        self.vm.cmd("blockdev-add", driver="null-co",
+                    read_zeroes=True, node_name="cd1")
 
         # Attach a CD drive with cd0 inserted
-        result = self.vm.qmp("device_add", driver="scsi-cd",
-                             id="dev0", drive="cd0")
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd("device_add", driver="scsi-cd", id="dev0", drive="cd0")
 
         # Set I/O limits
         args = { "id": "dev0", "iops": 100, "iops_rd": 0, "iops_wr": 0,
                                 "bps":  50,  "bps_rd": 0,  "bps_wr": 0 }
-        result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **args)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd("block_set_io_throttle", conv_keys=False, **args)
 
         # Check that the I/O limits have been set
         result = self.vm.qmp("query-block")
@@ -403,12 +395,9 @@ class ThrottleTestRemovableMedia(iotests.QMPTestCase):
         self.assert_qmp(result, 'return[0]/inserted/bps',   50)
 
         # Now eject cd0 and insert cd1
-        result = self.vm.qmp("blockdev-open-tray", id='dev0')
-        self.assert_qmp(result, 'return', {})
-        result = self.vm.qmp("blockdev-remove-medium", id='dev0')
-        self.assert_qmp(result, 'return', {})
-        result = self.vm.qmp("blockdev-insert-medium", id='dev0', node_name='cd1')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd("blockdev-open-tray", id='dev0')
+        self.vm.cmd("blockdev-remove-medium", id='dev0')
+        self.vm.cmd("blockdev-insert-medium", id='dev0', node_name='cd1')
 
         # Check that the I/O limits are still the same
         result = self.vm.qmp("query-block")
@@ -416,16 +405,14 @@ class ThrottleTestRemovableMedia(iotests.QMPTestCase):
         self.assert_qmp(result, 'return[0]/inserted/bps',   50)
 
         # Eject cd1
-        result = self.vm.qmp("blockdev-remove-medium", id='dev0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd("blockdev-remove-medium", id='dev0')
 
         # Check that we can't set limits if the device has no medium
         result = self.vm.qmp("block_set_io_throttle", conv_keys=False, **args)
         self.assert_qmp(result, 'error/class', 'GenericError')
 
         # Remove the CD drive
-        result = self.vm.qmp("device_del", id='dev0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd("device_del", id='dev0')
 
 
 if __name__ == '__main__':
diff --git a/tests/qemu-iotests/118 b/tests/qemu-iotests/118
index cae52ffa5e..3a232fcb27 100755
--- a/tests/qemu-iotests/118
+++ b/tests/qemu-iotests/118
@@ -74,11 +74,9 @@ class ChangeBaseClass(iotests.QMPTestCase):
 class GeneralChangeTestsBaseClass(ChangeBaseClass):
 
     def test_blockdev_change_medium(self):
-        result = self.vm.qmp('blockdev-change-medium',
-                             id=self.device_name, filename=new_img,
-                             format=iotests.imgfmt)
-
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-change-medium',
+                    id=self.device_name, filename=new_img,
+                    format=iotests.imgfmt)
 
         self.wait_for_open()
         self.wait_for_close()
@@ -89,8 +87,7 @@ class GeneralChangeTestsBaseClass(ChangeBaseClass):
         self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
 
     def test_eject(self):
-        result = self.vm.qmp('eject', id=self.device_name, force=True)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('eject', id=self.device_name, force=True)
 
         self.wait_for_open()
 
@@ -100,8 +97,7 @@ class GeneralChangeTestsBaseClass(ChangeBaseClass):
         self.assert_qmp_absent(result, 'return[0]/inserted')
 
     def test_tray_eject_change(self):
-        result = self.vm.qmp('eject', id=self.device_name, force=True)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('eject', id=self.device_name, force=True)
 
         self.wait_for_open()
 
@@ -110,9 +106,8 @@ class GeneralChangeTestsBaseClass(ChangeBaseClass):
             self.assert_qmp(result, 'return[0]/tray_open', True)
         self.assert_qmp_absent(result, 'return[0]/inserted')
 
-        result = self.vm.qmp('blockdev-change-medium', id=self.device_name,
-                             filename=new_img, format=iotests.imgfmt)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-change-medium', id=self.device_name,
+                    filename=new_img, format=iotests.imgfmt)
 
         self.wait_for_close()
 
@@ -122,9 +117,8 @@ class GeneralChangeTestsBaseClass(ChangeBaseClass):
         self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
 
     def test_tray_open_close(self):
-        result = self.vm.qmp('blockdev-open-tray',
-                             id=self.device_name, force=True)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-open-tray',
+                    id=self.device_name, force=True)
 
         self.wait_for_open()
 
@@ -136,8 +130,7 @@ class GeneralChangeTestsBaseClass(ChangeBaseClass):
         else:
             self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
 
-        result = self.vm.qmp('blockdev-close-tray', id=self.device_name)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-close-tray', id=self.device_name)
 
         if self.has_real_tray or not self.was_empty:
             self.wait_for_close()
@@ -151,8 +144,7 @@ class GeneralChangeTestsBaseClass(ChangeBaseClass):
             self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
 
     def test_tray_eject_close(self):
-        result = self.vm.qmp('eject', id=self.device_name, force=True)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('eject', id=self.device_name, force=True)
 
         self.wait_for_open()
 
@@ -161,8 +153,7 @@ class GeneralChangeTestsBaseClass(ChangeBaseClass):
             self.assert_qmp(result, 'return[0]/tray_open', True)
         self.assert_qmp_absent(result, 'return[0]/inserted')
 
-        result = self.vm.qmp('blockdev-close-tray', id=self.device_name)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-close-tray', id=self.device_name)
 
         self.wait_for_close()
 
@@ -172,9 +163,7 @@ class GeneralChangeTestsBaseClass(ChangeBaseClass):
         self.assert_qmp_absent(result, 'return[0]/inserted')
 
     def test_tray_open_change(self):
-        result = self.vm.qmp('blockdev-open-tray', id=self.device_name,
-                                                   force=True)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-open-tray', id=self.device_name, force=True)
 
         self.wait_for_open()
 
@@ -186,10 +175,8 @@ class GeneralChangeTestsBaseClass(ChangeBaseClass):
         else:
             self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
 
-        result = self.vm.qmp('blockdev-change-medium', id=self.device_name,
-                                                       filename=new_img,
-                                                       format=iotests.imgfmt)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-change-medium', id=self.device_name,
+                    filename=new_img, format=iotests.imgfmt)
 
         self.wait_for_close()
 
@@ -199,17 +186,14 @@ class GeneralChangeTestsBaseClass(ChangeBaseClass):
         self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
 
     def test_cycle(self, read_only_node=False):
-        result = self.vm.qmp('blockdev-add',
-                             node_name='new',
-                             driver=iotests.imgfmt,
-                             read_only=read_only_node,
-                             file={'filename': new_img,
-                                    'driver': 'file'})
-        self.assert_qmp(result, 'return', {})
-
-        result = self.vm.qmp('blockdev-open-tray',
-                             id=self.device_name, force=True)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add',
+                    node_name='new',
+                    driver=iotests.imgfmt,
+                    read_only=read_only_node,
+                    file={'filename': new_img,
+                          'driver': 'file'})
+
+        self.vm.cmd('blockdev-open-tray', id=self.device_name, force=True)
 
         self.wait_for_open()
 
@@ -221,26 +205,22 @@ class GeneralChangeTestsBaseClass(ChangeBaseClass):
         else:
             self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
 
-        result = self.vm.qmp('blockdev-remove-medium',
-                             id=self.device_name)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-remove-medium', id=self.device_name)
 
         result = self.vm.qmp('query-block')
         if self.has_real_tray:
             self.assert_qmp(result, 'return[0]/tray_open', True)
         self.assert_qmp_absent(result, 'return[0]/inserted')
 
-        result = self.vm.qmp('blockdev-insert-medium',
-                             id=self.device_name, node_name='new')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-insert-medium',
+                    id=self.device_name, node_name='new')
 
         result = self.vm.qmp('query-block')
         if self.has_real_tray:
             self.assert_qmp(result, 'return[0]/tray_open', True)
         self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
 
-        result = self.vm.qmp('blockdev-close-tray', id=self.device_name)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-close-tray', id=self.device_name)
 
         self.wait_for_close()
 
@@ -253,9 +233,8 @@ class GeneralChangeTestsBaseClass(ChangeBaseClass):
         self.test_cycle(True)
 
     def test_close_on_closed(self):
-        result = self.vm.qmp('blockdev-close-tray', id=self.device_name)
         # Should be a no-op
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-close-tray', id=self.device_name)
         self.assertEqual(self.vm.get_qmp_events(wait=False), [])
 
     def test_remove_on_closed(self):
@@ -269,12 +248,11 @@ class GeneralChangeTestsBaseClass(ChangeBaseClass):
         if not self.has_real_tray:
             return
 
-        result = self.vm.qmp('blockdev-add',
-                             node_name='new',
-                             driver=iotests.imgfmt,
-                             file={'filename': new_img,
-                                   'driver': 'file'})
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add',
+                    node_name='new',
+                    driver=iotests.imgfmt,
+                    file={'filename': new_img,
+                          'driver': 'file'})
 
         result = self.vm.qmp('blockdev-insert-medium', id=self.device_name,
                                                        node_name='new')
@@ -307,15 +285,13 @@ class TestInitiallyFilled(GeneralChangeTestsBaseClass):
         os.remove(new_img)
 
     def test_insert_on_filled(self):
-        result = self.vm.qmp('blockdev-add',
-                             node_name='new',
-                             driver=iotests.imgfmt,
-                             file={'filename': new_img,
-                                   'driver': 'file'})
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add',
+                    node_name='new',
+                    driver=iotests.imgfmt,
+                    file={'filename': new_img,
+                          'driver': 'file'})
 
-        result = self.vm.qmp('blockdev-open-tray', id=self.device_name)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-open-tray', id=self.device_name)
 
         self.wait_for_open()
 
@@ -344,14 +320,12 @@ class TestInitiallyEmpty(GeneralChangeTestsBaseClass):
         os.remove(new_img)
 
     def test_remove_on_empty(self):
-        result = self.vm.qmp('blockdev-open-tray', id=self.device_name)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-open-tray', id=self.device_name)
 
         self.wait_for_open()
 
-        result = self.vm.qmp('blockdev-remove-medium', id=self.device_name)
         # Should be a no-op
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-remove-medium', id=self.device_name)
 
 # Do this in a function to avoid leaking variables like case into the global
 # name space (otherwise tests would be run for the abstract base classes)
@@ -399,11 +373,10 @@ class TestChangeReadOnly(ChangeBaseClass):
         self.assert_qmp(result, 'return[0]/inserted/ro', True)
         self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
 
-        result = self.vm.qmp('blockdev-change-medium', id=self.device_name,
-                                                       filename=new_img,
-                                                       format=iotests.imgfmt,
-                                                       read_only_mode='retain')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-change-medium', id=self.device_name,
+                    filename=new_img,
+                    format=iotests.imgfmt,
+                    read_only_mode='retain')
 
         result = self.vm.qmp('query-block')
         self.assert_qmp(result, 'return[0]/inserted/ro', True)
@@ -419,11 +392,10 @@ class TestChangeReadOnly(ChangeBaseClass):
         self.assert_qmp(result, 'return[0]/inserted/ro', True)
         self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
 
-        result = self.vm.qmp('blockdev-change-medium', id=self.device_name,
-                                                       filename=new_img,
-                                                       format=iotests.imgfmt,
-                                                       read_only_mode='retain')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-change-medium', id=self.device_name,
+                    filename=new_img,
+                    format=iotests.imgfmt,
+                    read_only_mode='retain')
 
         result = self.vm.qmp('query-block')
         self.assert_qmp(result, 'return[0]/inserted/ro', True)
@@ -462,12 +434,11 @@ class TestChangeReadOnly(ChangeBaseClass):
         self.assert_qmp(result, 'return[0]/inserted/ro', True)
         self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
 
-        result = self.vm.qmp('blockdev-change-medium',
-                             id=self.device_name,
-                             filename=new_img,
-                             format=iotests.imgfmt,
-                             read_only_mode='read-write')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-change-medium',
+                    id=self.device_name,
+                    filename=new_img,
+                    format=iotests.imgfmt,
+                    read_only_mode='read-write')
 
         result = self.vm.qmp('query-block')
         self.assert_qmp(result, 'return[0]/inserted/ro', False)
@@ -483,12 +454,11 @@ class TestChangeReadOnly(ChangeBaseClass):
         self.assert_qmp(result, 'return[0]/inserted/ro', False)
         self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
 
-        result = self.vm.qmp('blockdev-change-medium',
-                             id=self.device_name,
-                             filename=new_img,
-                             format=iotests.imgfmt,
-                             read_only_mode='read-only')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-change-medium',
+                    id=self.device_name,
+                    filename=new_img,
+                    format=iotests.imgfmt,
+                    read_only_mode='read-only')
 
         result = self.vm.qmp('query-block')
         self.assert_qmp(result, 'return[0]/inserted/ro', True)
@@ -503,12 +473,11 @@ class TestChangeReadOnly(ChangeBaseClass):
         self.assert_qmp(result, 'return[0]/inserted/ro', False)
         self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
 
-        result = self.vm.qmp('blockdev-change-medium',
-                             id=self.device_name,
-                             filename=new_img,
-                             format=iotests.imgfmt,
-                             read_only_mode='read-only')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-change-medium',
+                    id=self.device_name,
+                    filename=new_img,
+                    format=iotests.imgfmt,
+                    read_only_mode='read-only')
 
         result = self.vm.qmp('query-block')
         self.assert_qmp(result, 'return[0]/inserted/ro', True)
@@ -546,11 +515,10 @@ class TestChangeReadOnly(ChangeBaseClass):
         self.assert_qmp(result, 'return[0]/inserted/ro', True)
         self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
 
-        result = self.vm.qmp('blockdev-change-medium', id=self.device_name,
-                                                       filename=new_img,
-                                                       format=iotests.imgfmt,
-                                                       read_only_mode='retain')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-change-medium', id=self.device_name,
+                    filename=new_img,
+                    format=iotests.imgfmt,
+                    read_only_mode='retain')
 
         result = self.vm.qmp('query-block')
         self.assert_qmp(result, 'return[0]/inserted/ro', True)
@@ -587,27 +555,24 @@ class TestChangeReadOnly(ChangeBaseClass):
         self.assert_qmp(result, 'return[0]/inserted/ro', False)
         self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
 
-        result = self.vm.qmp('blockdev-add',
-                             node_name='new',
-                             driver=iotests.imgfmt,
-                             read_only=True,
-                             file={'filename': new_img,
-                                    'driver': 'file'})
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add',
+                    node_name='new',
+                    driver=iotests.imgfmt,
+                    read_only=True,
+                    file={'filename': new_img,
+                          'driver': 'file'})
 
         result = self.vm.qmp('query-block')
         self.assert_qmp(result, 'return[0]/inserted/ro', False)
         self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
 
-        result = self.vm.qmp('blockdev-remove-medium', id=self.device_name)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-remove-medium', id=self.device_name)
 
         result = self.vm.qmp('query-block')
         self.assert_qmp_absent(result, 'return[0]/inserted')
 
-        result = self.vm.qmp('blockdev-insert-medium', id=self.device_name,
-                                                       node_name='new')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-insert-medium', id=self.device_name,
+                    node_name='new')
 
         result = self.vm.qmp('query-block')
         self.assert_qmp(result, 'return[0]/inserted/ro', True)
@@ -638,22 +603,19 @@ class TestBlockJobsAfterCycle(ChangeBaseClass):
 
         # For device-less BBs, calling blockdev-open-tray or blockdev-close-tray
         # is not necessary
-        result = self.vm.qmp('blockdev-remove-medium', id=self.device_name)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-remove-medium', id=self.device_name)
 
         result = self.vm.qmp('query-block')
         self.assert_qmp_absent(result, 'return[0]/inserted')
 
-        result = self.vm.qmp('blockdev-add',
-                             node_name='node0',
-                             driver=iotests.imgfmt,
-                             file={'filename': old_img,
-                                   'driver': 'file'})
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add',
+                    node_name='node0',
+                    driver=iotests.imgfmt,
+                    file={'filename': old_img,
+                          'driver': 'file'})
 
-        result = self.vm.qmp('blockdev-insert-medium', id=self.device_name,
-                                                       node_name='node0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-insert-medium', id=self.device_name,
+                    node_name='node0')
 
         result = self.vm.qmp('query-block')
         self.assert_qmp(result, 'return[0]/inserted/image/filename', old_img)
@@ -670,10 +632,9 @@ class TestBlockJobsAfterCycle(ChangeBaseClass):
     @iotests.skip_for_formats(('vpc', 'parallels', 'qcow', 'vdi', 'vmdk', 'raw',
                                'vhdx'))
     def test_snapshot_and_commit(self):
-        result = self.vm.qmp('blockdev-snapshot-sync', device='drive0',
-                                                       snapshot_file=new_img,
-                                                       format=iotests.imgfmt)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-snapshot-sync', device='drive0',
+                    snapshot_file=new_img,
+                    format=iotests.imgfmt)
 
         result = self.vm.qmp('query-block')
         self.assert_qmp(result, 'return[0]/inserted/image/filename', new_img)
@@ -681,16 +642,14 @@ class TestBlockJobsAfterCycle(ChangeBaseClass):
                         'return[0]/inserted/image/backing-image/filename',
                         old_img)
 
-        result = self.vm.qmp('block-commit', device='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit', device='drive0')
 
         self.vm.event_wait(name='BLOCK_JOB_READY')
 
         result = self.vm.qmp('query-block-jobs')
         self.assert_qmp(result, 'return[0]/device', 'drive0')
 
-        result = self.vm.qmp('block-job-complete', device='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-complete', device='drive0')
 
         self.vm.event_wait(name='BLOCK_JOB_COMPLETED')
 
diff --git a/tests/qemu-iotests/124 b/tests/qemu-iotests/124
index 845ab5303c..3f3febd1fc 100755
--- a/tests/qemu-iotests/124
+++ b/tests/qemu-iotests/124
@@ -201,9 +201,8 @@ class TestIncrementalBackupBase(iotests.QMPTestCase):
     def add_bitmap(self, name, drive, **kwargs):
         bitmap = Bitmap(name, drive)
         self.bitmaps.append(bitmap)
-        result = self.vm.qmp('block-dirty-bitmap-add', node=drive['id'],
-                             name=bitmap.name, **kwargs)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-dirty-bitmap-add', node=drive['id'],
+                    name=bitmap.name, **kwargs)
         return bitmap
 
 
@@ -388,13 +387,12 @@ class TestIncrementalBackup(TestIncrementalBackupBase):
                                           ('0x64', '32736k', '64k')))
         bitmap1 = self.add_bitmap('bitmap1', drive0)
 
-        result = self.vm.qmp('transaction', actions=[
+        self.vm.cmd('transaction', actions=[
             transaction_bitmap_clear(bitmap0.drive['id'], bitmap0.name),
             transaction_bitmap_clear(bitmap1.drive['id'], bitmap1.name),
             transaction_drive_backup(drive0['id'], drive0['backup'],
                                      sync='full', format=drive0['fmt'])
         ])
-        self.assert_qmp(result, 'return', {})
         self.wait_until_completed(drive0['id'])
         self.files.append(drive0['backup'])
 
@@ -417,7 +415,7 @@ class TestIncrementalBackup(TestIncrementalBackupBase):
                                            ('0xcd', '32M', '124k')))
 
         # Create a blkdebug interface to this img as 'drive1'
-        result = self.vm.qmp('blockdev-add',
+        self.vm.cmd('blockdev-add',
             node_name=drive1['id'],
             driver=drive1['fmt'],
             file={
@@ -440,7 +438,6 @@ class TestIncrementalBackup(TestIncrementalBackupBase):
                 }],
             }
         )
-        self.assert_qmp(result, 'return', {})
 
         # Create bitmaps and full backups for both drives
         drive0 = self.drives[0]
@@ -475,9 +472,8 @@ class TestIncrementalBackup(TestIncrementalBackupBase):
                                      format=drive1['fmt'], mode='existing',
                                      bitmap=dr1bm0.name)
         ]
-        result = self.vm.qmp('transaction', actions=transaction,
-                             properties={'completion-mode': 'grouped'} )
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('transaction', actions=transaction,
+                    properties={'completion-mode': 'grouped'} )
 
         # Observe that drive0's backup is cancelled and drive1 completes with
         # an error.
@@ -504,9 +500,8 @@ class TestIncrementalBackup(TestIncrementalBackupBase):
         target1 = self.prepare_backup(dr1bm0)
 
         # Re-run the exact same transaction.
-        result = self.vm.qmp('transaction', actions=transaction,
-                             properties={'completion-mode':'grouped'})
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('transaction', actions=transaction,
+                    properties={'completion-mode':'grouped'})
 
         # Both should complete successfully this time.
         self.assertTrue(self.wait_qmp_backup(drive0['id']))
@@ -617,7 +612,7 @@ class TestIncrementalBackupBlkdebug(TestIncrementalBackupBase):
         '''
 
         drive0 = self.drives[0]
-        result = self.vm.qmp('blockdev-add',
+        self.vm.cmd('blockdev-add',
             node_name=drive0['id'],
             driver=drive0['fmt'],
             file={
@@ -640,7 +635,6 @@ class TestIncrementalBackupBlkdebug(TestIncrementalBackupBase):
                 }],
             }
         )
-        self.assert_qmp(result, 'return', {})
 
         self.create_anchor_backup(drive0)
         self.add_bitmap('bitmap0', drive0)
@@ -668,29 +662,28 @@ class TestIncrementalBackupBlkdebug(TestIncrementalBackupBase):
         drive0 = self.drives[0]
         # NB: The blkdebug script here looks for a "flush, read" pattern.
         # The flush occurs in hmp_io_writes, and the read during the block job.
-        result = self.vm.qmp('blockdev-add',
-                             node_name=drive0['id'],
-                             driver=drive0['fmt'],
-                             file={
-                                 'driver': 'blkdebug',
-                                 'image': {
-                                     'driver': 'file',
-                                     'filename': drive0['file']
-                                 },
-                                 'set-state': [{
-                                     'event': 'flush_to_disk',
-                                     'state': 1,
-                                     'new_state': 2
-                                 }],
-                                 'inject-error': [{
-                                     'event': 'read_aio',
-                                     'errno': 5,
-                                     'state': 2,
-                                     'immediately': False,
-                                     'once': True
-                                 }],
-                             })
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add',
+                    node_name=drive0['id'],
+                    driver=drive0['fmt'],
+                    file={
+                        'driver': 'blkdebug',
+                        'image': {
+                            'driver': 'file',
+                            'filename': drive0['file']
+                        },
+                        'set-state': [{
+                            'event': 'flush_to_disk',
+                            'state': 1,
+                            'new_state': 2
+                        }],
+                        'inject-error': [{
+                            'event': 'read_aio',
+                            'errno': 5,
+                            'state': 2,
+                            'immediately': False,
+                            'once': True
+                        }],
+                    })
         self.create_anchor_backup(drive0)
         bitmap = self.add_bitmap('bitmap0', drive0)
 
diff --git a/tests/qemu-iotests/129 b/tests/qemu-iotests/129
index c75ec62ecf..cc39f2b6ed 100755
--- a/tests/qemu-iotests/129
+++ b/tests/qemu-iotests/129
@@ -55,11 +55,9 @@ class TestStopWithBlockJob(iotests.QMPTestCase):
     def do_test_stop(self, cmd, **args):
         """Test 'stop' while block job is running on a throttled drive.
         The 'stop' command shouldn't drain the job"""
-        result = self.vm.qmp(cmd, **args)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd(cmd, **args)
 
-        result = self.vm.qmp("stop")
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd("stop")
         result = self.vm.qmp("query-block-jobs")
 
         self.assert_qmp(result, 'return[0]/status', 'running')
@@ -87,7 +85,7 @@ class TestStopWithBlockJob(iotests.QMPTestCase):
         iotests.qemu_img('create', '-f', iotests.imgfmt, self.overlay_img,
                          '1G')
 
-        result = self.vm.qmp('blockdev-add', **{
+        self.vm.cmd('blockdev-add', {
             'node-name': 'overlay',
             'driver': iotests.imgfmt,
             'file': {
@@ -95,11 +93,8 @@ class TestStopWithBlockJob(iotests.QMPTestCase):
                 'filename': self.overlay_img
             }
         })
-        self.assert_qmp(result, 'return', {})
 
-        result = self.vm.qmp('blockdev-snapshot',
-                             node='source', overlay='overlay')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-snapshot', node='source', overlay='overlay')
 
         self.do_test_stop('block-commit', device='drive0', top_node='source')
 
diff --git a/tests/qemu-iotests/132 b/tests/qemu-iotests/132
index 367ea08036..12a64b3d95 100755
--- a/tests/qemu-iotests/132
+++ b/tests/qemu-iotests/132
@@ -47,9 +47,8 @@ class TestSingleDrive(iotests.QMPTestCase):
             pass
 
     def test_mirror_discard(self):
-        result = self.vm.qmp('drive-mirror', device='drive0', sync='full',
-                             target=target_img)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', device='drive0', sync='full',
+                    target=target_img)
         self.vm.hmp_qemu_io('drive0', 'discard 0 64k')
         self.complete_and_wait('drive0')
         self.vm.shutdown()
diff --git a/tests/qemu-iotests/139 b/tests/qemu-iotests/139
index 178b1ee230..9fea38adff 100755
--- a/tests/qemu-iotests/139
+++ b/tests/qemu-iotests/139
@@ -58,8 +58,7 @@ class TestBlockdevDel(iotests.QMPTestCase):
                 'file': {'driver': 'file',
                          'node-name': file_node,
                          'filename': base_img}}
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
         self.checkBlockDriverState(node)
         self.checkBlockDriverState(file_node)
 
@@ -73,8 +72,7 @@ class TestBlockdevDel(iotests.QMPTestCase):
                 'backing': None,
                 'file': {'driver': 'file',
                          'filename': new_img}}
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
         self.checkBlockDriverState(node)
 
     # Delete a BlockDriverState
@@ -89,17 +87,14 @@ class TestBlockdevDel(iotests.QMPTestCase):
 
     # Add a device model
     def addDeviceModel(self, device, backend, driver = 'virtio-blk'):
-        result = self.vm.qmp('device_add', id = device,
-                             driver = driver, drive = backend)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('device_add', id = device,
+                    driver = driver, drive = backend)
 
     # Delete a device model
     def delDeviceModel(self, device, is_virtio_blk = True):
-        result = self.vm.qmp('device_del', id = device)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('device_del', id = device)
 
-        result = self.vm.qmp('system_reset')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('system_reset')
 
         if is_virtio_blk:
             device_path = '/machine/peripheral/%s/virtio-backend' % device
@@ -126,9 +121,7 @@ class TestBlockdevDel(iotests.QMPTestCase):
     # Insert a BlockDriverState
     def insertDrive(self, device, node):
         self.checkBlockDriverState(node)
-        result = self.vm.qmp('blockdev-insert-medium',
-                             id = device, node_name = node)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-insert-medium', id = device, node_name = node)
         self.checkBlockDriverState(node)
 
     # Create a snapshot using 'blockdev-snapshot-sync'
@@ -139,8 +132,7 @@ class TestBlockdevDel(iotests.QMPTestCase):
                 'snapshot-file': new_img,
                 'snapshot-node-name': overlay,
                 'format': iotests.imgfmt}
-        result = self.vm.qmp('blockdev-snapshot-sync', conv_keys=False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-snapshot-sync', conv_keys=False, **opts)
         self.checkBlockDriverState(node)
         self.checkBlockDriverState(overlay)
 
@@ -148,9 +140,7 @@ class TestBlockdevDel(iotests.QMPTestCase):
     def createSnapshot(self, node, overlay):
         self.checkBlockDriverState(node)
         self.checkBlockDriverState(overlay)
-        result = self.vm.qmp('blockdev-snapshot',
-                             node = node, overlay = overlay)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-snapshot', node = node, overlay = overlay)
         self.checkBlockDriverState(node)
         self.checkBlockDriverState(overlay)
 
@@ -163,14 +153,12 @@ class TestBlockdevDel(iotests.QMPTestCase):
                 'node-name': new_node,
                 'sync': 'top',
                 'format': iotests.imgfmt}
-        result = self.vm.qmp('drive-mirror', conv_keys=False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('drive-mirror', conv_keys=False, **opts)
         self.checkBlockDriverState(new_node)
 
     # Complete an existing block job
     def completeBlockJob(self, id, node_before, node_after):
-        result = self.vm.qmp('block-job-complete', device=id)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-complete', device=id)
         self.wait_until_completed(id)
 
     # Add a BlkDebug node
@@ -186,8 +174,7 @@ class TestBlockdevDel(iotests.QMPTestCase):
         opts = {'driver': 'blkdebug',
                 'node-name': debug,
                 'image': image}
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
         self.checkBlockDriverState(node)
         self.checkBlockDriverState(debug)
 
@@ -211,8 +198,7 @@ class TestBlockdevDel(iotests.QMPTestCase):
                 'node-name': blkverify,
                 'test': node_0,
                 'raw': node_1}
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
         self.checkBlockDriverState(test)
         self.checkBlockDriverState(raw)
         self.checkBlockDriverState(blkverify)
@@ -235,8 +221,7 @@ class TestBlockdevDel(iotests.QMPTestCase):
                 'node-name': quorum,
                 'vote-threshold': 1,
                 'children': [ child_0, child_1 ]}
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
         self.checkBlockDriverState(child0)
         self.checkBlockDriverState(child1)
         self.checkBlockDriverState(quorum)
diff --git a/tests/qemu-iotests/147 b/tests/qemu-iotests/147
index 47dfa62e6b..8c5e08bf2b 100755
--- a/tests/qemu-iotests/147
+++ b/tests/qemu-iotests/147
@@ -58,8 +58,7 @@ class NBDBlockdevAddBase(iotests.QMPTestCase):
     def client_test(self, filename, address, export=None,
                     node_name='nbd-blockdev', delete=True):
         bao = self.blockdev_add_options(address, export, node_name)
-        result = self.vm.qmp('blockdev-add', **bao)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', **bao)
 
         found = False
         result = self.vm.qmp('query-named-block-nodes')
@@ -75,8 +74,7 @@ class NBDBlockdevAddBase(iotests.QMPTestCase):
         self.assertTrue(found)
 
         if delete:
-            result = self.vm.qmp('blockdev-del', node_name=node_name)
-            self.assert_qmp(result, 'return', {})
+            self.vm.cmd('blockdev-del', node_name=node_name)
 
 
 class QemuNBD(NBDBlockdevAddBase):
@@ -158,16 +156,14 @@ class BuiltinNBD(NBDBlockdevAddBase):
         self.assert_qmp(result, 'return', {})
 
         if export_name is None:
-            result = self.server.qmp('nbd-server-add', device='nbd-export')
+            self.server.cmd('nbd-server-add', device='nbd-export')
         else:
-            result = self.server.qmp('nbd-server-add', device='nbd-export',
-                                     name=export_name)
-        self.assert_qmp(result, 'return', {})
+            self.server.cmd('nbd-server-add', device='nbd-export',
+                            name=export_name)
 
         if export_name2 is not None:
-            result = self.server.qmp('nbd-server-add', device='nbd-export',
-                                     name=export_name2)
-            self.assert_qmp(result, 'return', {})
+            self.server.cmd('nbd-server-add', device='nbd-export',
+                            name=export_name2)
 
         return True
 
@@ -175,8 +171,7 @@ class BuiltinNBD(NBDBlockdevAddBase):
         self.assertTrue(self._try_server_up(address, export_name, export_name2))
 
     def _server_down(self):
-        result = self.server.qmp('nbd-server-stop')
-        self.assert_qmp(result, 'return', {})
+        self.server.cmd('nbd-server-stop')
 
     def do_test_inet(self, export_name=None):
         while True:
@@ -218,10 +213,8 @@ class BuiltinNBD(NBDBlockdevAddBase):
                          flatten_sock_addr(address), 'exp1', 'node1', False)
         self.client_test('nbd://localhost:%i/%s' % (nbd_port, 'exp2'),
                          flatten_sock_addr(address), 'exp2', 'node2', False)
-        result = self.vm.qmp('blockdev-del', node_name='node1')
-        self.assert_qmp(result, 'return', {})
-        result = self.vm.qmp('blockdev-del', node_name='node2')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', node_name='node1')
+        self.vm.cmd('blockdev-del', node_name='node2')
         self._server_down()
 
     def test_inet6(self):
@@ -272,8 +265,7 @@ class BuiltinNBD(NBDBlockdevAddBase):
         result = self.vm.send_fd_scm(fd=sockfd.fileno())
         self.assertEqual(result, 0, 'Failed to send socket FD')
 
-        result = self.vm.qmp('getfd', fdname='nbd-fifo')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('getfd', fdname='nbd-fifo')
 
         address = { 'type': 'fd',
                     'data': { 'str': 'nbd-fifo' } }
diff --git a/tests/qemu-iotests/151 b/tests/qemu-iotests/151
index 93d14193d0..26154d3d0c 100755
--- a/tests/qemu-iotests/151
+++ b/tests/qemu-iotests/151
@@ -75,14 +75,13 @@ class TestActiveMirror(iotests.QMPTestCase):
             self.vm.hmp_qemu_io('source', 'aio_write -z %i 1M' % offset)
 
         # Start the block job
-        result = self.vm.qmp('blockdev-mirror',
-                             job_id='mirror',
-                             filter_node_name='mirror-node',
-                             device='source-node',
-                             target='target-node',
-                             sync='full',
-                             copy_mode='write-blocking')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-mirror',
+                    job_id='mirror',
+                    filter_node_name='mirror-node',
+                    device='source-node',
+                    target='target-node',
+                    sync='full',
+                    copy_mode='write-blocking')
 
         # Start some more requests
         for offset in range(3 * self.image_len // 8, 5 * self.image_len // 8, 1024 * 1024):
@@ -121,23 +120,21 @@ class TestActiveMirror(iotests.QMPTestCase):
         result = self.vm.hmp_qemu_io('source', 'write -P 1 0 2M')
 
         # Start the block job (very slowly)
-        result = self.vm.qmp('blockdev-mirror',
-                             job_id='mirror',
-                             filter_node_name='mirror-node',
-                             device='source-node',
-                             target='target-node',
-                             sync='full',
-                             copy_mode='write-blocking',
-                             buf_size=(1048576 // 4),
-                             speed=1)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-mirror',
+                    job_id='mirror',
+                    filter_node_name='mirror-node',
+                    device='source-node',
+                    target='target-node',
+                    sync='full',
+                    copy_mode='write-blocking',
+                    buf_size=(1048576 // 4),
+                    speed=1)
 
         # Start an unaligned request to a dirty area
         result = self.vm.hmp_qemu_io('source', 'write -P 2 %i 1' % (1048576 + 42))
 
         # Let the job finish
-        result = self.vm.qmp('block-job-set-speed', device='mirror', speed=0)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-set-speed', device='mirror', speed=0)
         self.complete_and_wait(drive='mirror')
 
         self.potential_writes_in_flight = False
@@ -185,8 +182,7 @@ class TestActiveMirror(iotests.QMPTestCase):
         # After resuming 4, one of 2 and 3 goes first and set in_flight_bitmap,
         # so the other will wait for it.
 
-        result = self.vm.qmp('block-job-set-speed', device='mirror', speed=0)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-set-speed', device='mirror', speed=0)
         self.complete_and_wait(drive='mirror')
 
         self.potential_writes_in_flight = False
diff --git a/tests/qemu-iotests/155 b/tests/qemu-iotests/155
index eadda52615..6b1625b8f3 100755
--- a/tests/qemu-iotests/155
+++ b/tests/qemu-iotests/155
@@ -110,8 +110,7 @@ class BaseClass(iotests.QMPTestCase):
                 elif self.target_blockdev_backing:
                         options['backing'] = self.target_blockdev_backing
 
-                result = self.vm.qmp('blockdev-add', **options)
-                self.assert_qmp(result, 'return', {})
+                self.vm.cmd('blockdev-add', **options)
 
     def tearDown(self):
         self.vm.shutdown()
@@ -178,20 +177,18 @@ class MirrorBaseClass(BaseClass):
 
     def runMirror(self, sync):
         if self.cmd == 'blockdev-mirror':
-            result = self.vm.qmp(self.cmd, job_id='mirror-job', device='source',
-                                 sync=sync, target='target',
-                                 auto_finalize=False)
+            self.vm.cmd(self.cmd, job_id='mirror-job', device='source',
+                        sync=sync, target='target',
+                        auto_finalize=False)
         else:
             if self.existing:
                 mode = 'existing'
             else:
                 mode = 'absolute-paths'
-            result = self.vm.qmp(self.cmd, job_id='mirror-job', device='source',
-                                 sync=sync, target=target_img,
-                                 format=iotests.imgfmt, mode=mode,
-                                 node_name='target', auto_finalize=False)
-
-        self.assert_qmp(result, 'return', {})
+            self.vm.cmd(self.cmd, job_id='mirror-job', device='source',
+                        sync=sync, target=target_img,
+                        format=iotests.imgfmt, mode=mode,
+                        node_name='target', auto_finalize=False)
 
         self.vm.run_job('mirror-job', auto_finalize=False,
                         pre_finalize=self.openBacking, auto_dismiss=True)
@@ -258,16 +255,14 @@ class TestBlockdevMirrorReopen(MirrorBaseClass):
 
     def openBacking(self):
         if not self.target_open_with_backing:
-            result = self.vm.qmp('blockdev-add', node_name="backing",
-                                 driver="null-co")
-            self.assert_qmp(result, 'return', {})
-            result = self.vm.qmp('blockdev-reopen', options=[{
-                                     'node-name': "target",
-                                     'driver': iotests.imgfmt,
-                                     'file': "target-file",
-                                     'backing': "backing"
-                                 }])
-            self.assert_qmp(result, 'return', {})
+            self.vm.cmd('blockdev-add', node_name="backing",
+                        driver="null-co")
+            self.vm.cmd('blockdev-reopen', options=[{
+                'node-name': "target",
+                'driver': iotests.imgfmt,
+                'file': "target-file",
+                'backing': "backing"
+            }])
 
 class TestBlockdevMirrorReopenIothread(TestBlockdevMirrorReopen):
     use_iothread = True
@@ -281,12 +276,8 @@ class TestBlockdevMirrorSnapshot(MirrorBaseClass):
 
     def openBacking(self):
         if not self.target_open_with_backing:
-            result = self.vm.qmp('blockdev-add', node_name="backing",
-                                 driver="null-co")
-            self.assert_qmp(result, 'return', {})
-            result = self.vm.qmp('blockdev-snapshot', node="backing",
-                                 overlay="target")
-            self.assert_qmp(result, 'return', {})
+            self.vm.cmd('blockdev-add', node_name="backing", driver="null-co")
+            self.vm.cmd('blockdev-snapshot', node="backing", overlay="target")
 
 class TestBlockdevMirrorSnapshotIothread(TestBlockdevMirrorSnapshot):
     use_iothread = True
@@ -295,14 +286,12 @@ class TestCommit(BaseClass):
     existing = False
 
     def testCommit(self):
-        result = self.vm.qmp('block-commit', job_id='commit-job',
-                             device='source', base=back1_img)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit', job_id='commit-job',
+                    device='source', base=back1_img)
 
         self.vm.event_wait('BLOCK_JOB_READY')
 
-        result = self.vm.qmp('block-job-complete', device='commit-job')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-complete', device='commit-job')
 
         self.vm.event_wait('BLOCK_JOB_COMPLETED')
 
diff --git a/tests/qemu-iotests/165 b/tests/qemu-iotests/165
index e3ef28e2ee..028c6a15ca 100755
--- a/tests/qemu-iotests/165
+++ b/tests/qemu-iotests/165
@@ -116,9 +116,7 @@ class TestPersistentDirtyBitmap(iotests.QMPTestCase):
         sha256_2 = self.getSha256()
         assert sha256_1 != sha256_2 # Otherwise, it's not very interesting.
 
-        result = self.vm.qmp('block-dirty-bitmap-clear', node='drive0',
-                             name='bitmap0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-dirty-bitmap-clear', node='drive0', name='bitmap0')
 
         # Start with regions1
 
@@ -137,7 +135,7 @@ class TestPersistentDirtyBitmap(iotests.QMPTestCase):
         assert sha256_1 == self.getSha256()
 
         # Reopen to RW
-        result = self.vm.qmp('blockdev-reopen', options=[{
+        self.vm.cmd('blockdev-reopen', options=[{
             'node-name': 'node0',
             'driver': iotests.imgfmt,
             'file': {
@@ -146,7 +144,6 @@ class TestPersistentDirtyBitmap(iotests.QMPTestCase):
             },
             'read-only': False
         }])
-        self.assert_qmp(result, 'return', {})
 
         # Check that bitmap is reopened to RW and we can write to it.
         self.writeRegions(regions2)
diff --git a/tests/qemu-iotests/196 b/tests/qemu-iotests/196
index 76509a5ad1..e5105b1354 100755
--- a/tests/qemu-iotests/196
+++ b/tests/qemu-iotests/196
@@ -45,8 +45,7 @@ class TestInvalidateAutoclear(iotests.QMPTestCase):
         self.vm_b.add_incoming("exec: cat '" + migfile + "'")
 
     def test_migration(self):
-        result = self.vm_a.qmp('migrate', uri='exec:cat>' + migfile)
-        self.assert_qmp(result, 'return', {});
+        self.vm_a.cmd('migrate', uri='exec:cat>' + migfile)
         self.assertNotEqual(self.vm_a.event_wait("STOP"), None)
 
         with open(disk, 'r+b') as f:
diff --git a/tests/qemu-iotests/205 b/tests/qemu-iotests/205
index c0e107328f..5f5e595ee5 100755
--- a/tests/qemu-iotests/205
+++ b/tests/qemu-iotests/205
@@ -44,10 +44,8 @@ class TestNbdServerRemove(iotests.QMPTestCase):
             }
         }
 
-        result = self.vm.qmp('nbd-server-start', addr=address)
-        self.assert_qmp(result, 'return', {})
-        result = self.vm.qmp('nbd-server-add', device='drive0', name='exp')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('nbd-server-start', addr=address)
+        self.vm.cmd('nbd-server-add', device='drive0', name='exp')
 
     def tearDown(self):
         self.vm.shutdown()
diff --git a/tests/qemu-iotests/245 b/tests/qemu-iotests/245
index 8cbed7821b..6120cdd9ad 100755
--- a/tests/qemu-iotests/245
+++ b/tests/qemu-iotests/245
@@ -134,8 +134,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
     def test_incorrect_parameters_single_file(self):
         # Open 'hd0' only (no backing files)
         opts = hd_opts(0)
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
         original_graph = self.vm.qmp('query-named-block-nodes')
 
         # We can reopen the image passing the same options
@@ -169,8 +168,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         self.check_node_graph(original_graph)
 
         # Remove the node
-        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'hd0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd0')
 
     # This test opens an image with a backing file and tries to reopen
     # it with illegal / incorrect parameters.
@@ -178,8 +176,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         # Open hd1 omitting the backing options (hd0 will be opened
         # with the default options)
         opts = hd_opts(1)
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
         original_graph = self.vm.qmp('query-named-block-nodes')
 
         # We can't reopen the image passing the same options, 'backing' is mandatory
@@ -211,8 +208,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         self.check_node_graph(original_graph)
 
         # Remove the node
-        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'hd1')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd1')
 
     # Reopen an image several times changing some of its options
     def test_reopen(self):
@@ -225,8 +221,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         # Open the hd1 image passing all backing options
         opts = hd_opts(1)
         opts['backing'] = hd_opts(0)
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
         original_graph = self.vm.qmp('query-named-block-nodes')
 
         # We can reopen the image passing the same options
@@ -301,8 +296,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         self.assert_qmp_absent(self.get_node('hd1'), 'image/backing-image')
 
         # Open the 'hd0' image
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **hd_opts(0))
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **hd_opts(0))
 
         # Reopen the hd1 image setting 'hd0' as its backing image
         self.reopen(opts, {'backing': 'hd0'})
@@ -321,10 +315,8 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         self.assert_qmp(result, 'error/desc', "Node 'hd0' is busy: node is used as backing hd of 'hd1'")
 
         # But we can remove both nodes if done in the proper order
-        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'hd1')
-        self.assert_qmp(result, 'return', {})
-        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'hd0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd1')
+        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd0')
 
     # Reopen a raw image and see the effect of changing the 'offset' option
     def test_reopen_raw(self):
@@ -340,8 +332,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         qemu_io('-f', 'raw', '-c', 'write -P 0xa1 1M 1M', hd_path[0])
 
         # Open the raw file with QEMU
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         # Read 1MB from offset 0
         self.run_qemu_io("hd0", "read -P 0xa0  0 1M")
@@ -357,8 +348,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         self.run_qemu_io("hd0", "read -P 0xa0  0 1M")
 
         # Remove the block device
-        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'hd0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd0')
 
     # Omitting an option should reset it to the default value, but if
     # an option cannot be changed it shouldn't be possible to reset it
@@ -372,8 +362,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
                           'node-name': 'hd0-file' } }
 
         # Open the file with QEMU
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         # file.x-check-cache-dropped can be changed...
         self.reopen(opts, { 'file.x-check-cache-dropped': False })
@@ -389,8 +378,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         self.reopen(opts, { 'file.locking': 'off' })
 
         # Remove the block device
-        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'hd0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd0')
 
     # This test modifies the node graph a few times by changing the
     # 'backing' option on reopen and verifies that the guest data that
@@ -402,8 +390,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         for i in range(3):
             opts.append(hd_opts(i))
             opts[i]['backing'] = None
-            result = self.vm.qmp('blockdev-add', conv_keys = False, **opts[i])
-            self.assert_qmp(result, 'return', {})
+            self.vm.cmd('blockdev-add', conv_keys = False, **opts[i])
 
         # hd0
         self.run_qemu_io("hd0", "read -P 0xa0  0 1M")
@@ -494,8 +481,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         for i in range(3):
             opts.append(hd_opts(i))
             opts[i]['backing'] = None
-            result = self.vm.qmp('blockdev-add', conv_keys = False, **opts[i])
-            self.assert_qmp(result, 'return', {})
+            self.vm.cmd('blockdev-add', conv_keys = False, **opts[i])
 
         # hd1 <- hd0, hd1 <- hd2
         self.reopen(opts[0], {'backing': 'hd1'})
@@ -527,8 +513,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
                   'node-name': 'bv',
                   'test': 'hd0',
                   'raw': 'hd1'}
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **bvopts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **bvopts)
 
         # blkverify doesn't currently allow reopening. TODO: implement this
         self.reopen(bvopts, {}, "Block format 'blkverify' used by node 'bv'" +
@@ -539,8 +524,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
                     "Making 'bv' a backing child of 'hd0' would create a cycle")
 
         # Delete the blkverify node
-        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'bv')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'bv')
 
     # Replace the protocol layer ('file' parameter) of a disk image
     def test_replace_file(self):
@@ -551,16 +535,13 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         hd0_opts = {'driver': 'file', 'node-name': 'hd0-file', 'filename':  hd_path[0] }
         hd1_opts = {'driver': 'file', 'node-name': 'hd1-file', 'filename':  hd_path[1] }
 
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **hd0_opts)
-        self.assert_qmp(result, 'return', {})
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **hd1_opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **hd0_opts)
+        self.vm.cmd('blockdev-add', conv_keys = False, **hd1_opts)
 
         # Add a raw format layer that uses hd0-file as its protocol layer
         opts = {'driver': 'raw', 'node-name': 'hd', 'file': 'hd0-file'}
 
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         # Fill the image with data
         self.run_qemu_io("hd", "read  -P 0 0 10k")
@@ -583,21 +564,18 @@ class TestBlockdevReopen(iotests.QMPTestCase):
     def test_insert_throttle_filter(self):
         # Add an image to the VM
         hd0_opts = hd_opts(0)
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **hd0_opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **hd0_opts)
 
         # Create a throttle-group object
         opts = { 'qom-type': 'throttle-group', 'id': 'group0',
                  'limits': { 'iops-total': 1000 } }
-        result = self.vm.qmp('object-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('object-add', conv_keys = False, **opts)
 
         # Add a throttle filter with the group that we just created.
         # The filter is not used by anyone yet
         opts = { 'driver': 'throttle', 'node-name': 'throttle0',
                  'throttle-group': 'group0', 'file': 'hd0-file' }
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         # Insert the throttle filter between hd0 and hd0-file
         self.reopen(hd0_opts, {'file': 'throttle0'})
@@ -609,15 +587,13 @@ class TestBlockdevReopen(iotests.QMPTestCase):
     def test_insert_compress_filter(self):
         # Add an image to the VM: hd (raw) -> hd0 (qcow2) -> hd0-file (file)
         opts = {'driver': 'raw', 'node-name': 'hd', 'file': hd_opts(0)}
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         # Add a 'compress' filter
         filter_opts = {'driver': 'compress',
                        'node-name': 'compress0',
                        'file': 'hd0'}
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **filter_opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **filter_opts)
 
         # Unmap the beginning of the image (we cannot write compressed
         # data to an allocated cluster)
@@ -653,12 +629,10 @@ class TestBlockdevReopen(iotests.QMPTestCase):
     def test_swap_files(self):
         # Add hd0 and hd2 (none of them with backing files)
         opts0 = hd_opts(0)
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts0)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts0)
 
         opts2 = hd_opts(2)
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts2)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts2)
 
         # Write different data to both block devices
         self.run_qemu_io("hd0", "write -P 0xa0 0 1k")
@@ -706,15 +680,13 @@ class TestBlockdevReopen(iotests.QMPTestCase):
             opts = hd_opts(i)
             # Open all three images without backing file
             opts['backing'] = None
-            result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-            self.assert_qmp(result, 'return', {})
+            self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         opts = {'driver': 'quorum',
                 'node-name': 'quorum0',
                 'children': ['hd0', 'hd1', 'hd2'],
                 'vote-threshold': 2}
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         # Quorum doesn't currently allow reopening. TODO: implement this
         self.reopen(opts, {}, "Block format 'quorum' used by node 'quorum0'" +
@@ -726,14 +698,12 @@ class TestBlockdevReopen(iotests.QMPTestCase):
                     "Making 'quorum0' a backing child of 'hd0' would create a cycle")
 
         # Delete quorum0
-        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'quorum0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'quorum0')
 
         # Delete hd0, hd1 and hd2
         for i in range(3):
-            result = self.vm.qmp('blockdev-del', conv_keys = True,
-                                 node_name = 'hd%d' % i)
-            self.assert_qmp(result, 'return', {})
+            self.vm.cmd('blockdev-del', conv_keys = True,
+                        node_name = 'hd%d' % i)
 
         ######################
         ###### blkdebug ######
@@ -742,8 +712,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
                 'node-name': 'bd',
                 'config': '/dev/null',
                 'image': hd_opts(0)}
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         # blkdebug allows reopening if we keep the same options
         self.reopen(opts)
@@ -756,16 +725,14 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         self.reopen(opts, {}, "Option 'config' cannot be reset to its default value")
 
         # Delete the blkdebug node
-        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'bd')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'bd')
 
         ##################
         ###### null ######
         ##################
         opts = {'driver': 'null-co', 'node-name': 'root', 'size': 1024}
 
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         # 1 << 30 is the default value, but we cannot change it explicitly
         self.reopen(opts, {'size': (1 << 30)}, "Cannot change the option 'size'")
@@ -774,16 +741,14 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         del opts['size']
         self.reopen(opts, {}, "Option 'size' cannot be reset to its default value")
 
-        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'root')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'root')
 
         ##################
         ###### file ######
         ##################
         opts = hd_opts(0)
         opts['file']['locking'] = 'on'
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         # 'locking' cannot be changed
         del opts['file']['locking']
@@ -797,27 +762,23 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         self.reopen(opts, {'locking': 'off'}, "Cannot change the option 'locking'")
         self.reopen(opts, {}, "Option 'locking' cannot be reset to its default value")
 
-        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'hd0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd0')
 
         ######################
         ###### throttle ######
         ######################
         opts = { 'qom-type': 'throttle-group', 'id': 'group0',
                  'limits': { 'iops-total': 1000 } }
-        result = self.vm.qmp('object-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('object-add', conv_keys = False, **opts)
 
         opts = { 'qom-type': 'throttle-group', 'id': 'group1',
                  'limits': { 'iops-total': 2000 } }
-        result = self.vm.qmp('object-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('object-add', conv_keys = False, **opts)
 
         # Add a throttle filter with group = group0
         opts = { 'driver': 'throttle', 'node-name': 'throttle0',
                  'throttle-group': 'group0', 'file': hd_opts(0) }
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         # We can reopen it if we keep the same options
         self.reopen(opts)
@@ -845,16 +806,13 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         self.assert_qmp(result, 'error/desc', "object 'group0' is in use, can not be deleted")
 
         # But group1 is free this time, and it can be deleted
-        result = self.vm.qmp('object-del', id = 'group1')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('object-del', id = 'group1')
 
         # Let's delete the filter node
-        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'throttle0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'throttle0')
 
         # And we can finally get rid of group0
-        result = self.vm.qmp('object-del', id = 'group0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('object-del', id = 'group0')
 
     # If an image has a backing file then the 'backing' option must be
     # passed on reopen. We don't allow leaving the option out in this
@@ -862,13 +820,11 @@ class TestBlockdevReopen(iotests.QMPTestCase):
     def test_missing_backing_options_1(self):
         # hd2
         opts = hd_opts(2)
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         # hd0
         opts = hd_opts(0)
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         # hd0 has no backing file: we can omit the 'backing' option
         self.reopen(opts)
@@ -891,11 +847,9 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         self.reopen(opts)
 
         # Remove both hd0 and hd2
-        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'hd0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd0')
 
-        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'hd2')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd2')
 
     # If an image has default backing file (as part of its metadata)
     # then the 'backing' option must be passed on reopen. We don't
@@ -905,8 +859,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         # hd0 <- hd1
         # (hd0 is hd1's default backing file)
         opts = hd_opts(1)
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         # hd1 has a backing file: we can't omit the 'backing' option
         self.reopen(opts, {}, "backing is missing for 'hd1'")
@@ -917,8 +870,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         # No backing file attached to hd1 now, but we still can't omit the 'backing' option
         self.reopen(opts, {}, "backing is missing for 'hd1'")
 
-        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'hd1')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd1')
 
     # Test that making 'backing' a reference to an existing child
     # keeps its current options
@@ -931,8 +883,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         opts['detect-zeroes'] = 'on'
         opts['backing']['detect-zeroes'] = 'on'
         opts['backing']['backing']['detect-zeroes'] = 'on'
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         # Reopen the chain passing the minimum amount of required options.
         # By making 'backing' a reference to hd1 (instead of a sub-dict)
@@ -955,12 +906,10 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         opts = hd_opts(0)
         opts['backing'] = hd_opts(1)
         opts['backing']['backing'] = None
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         # Stream hd1 into hd0 and wait until it's done
-        result = self.vm.qmp('block-stream', conv_keys = True, job_id = 'stream0', device = 'hd0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', conv_keys = True, job_id = 'stream0', device = 'hd0')
         self.wait_until_completed(drive = 'stream0')
 
         # Now we have only hd0
@@ -976,8 +925,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         # We can also reopen hd0 if we set 'backing' to null
         self.reopen(opts, {'backing': None})
 
-        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'hd0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd0')
 
     # Another block_stream test
     def test_block_stream_2(self):
@@ -985,13 +933,11 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         opts = hd_opts(0)
         opts['backing'] = hd_opts(1)
         opts['backing']['backing'] = hd_opts(2)
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         # Stream hd1 into hd0 and wait until it's done
-        result = self.vm.qmp('block-stream', conv_keys = True, job_id = 'stream0',
-                             device = 'hd0', base_node = 'hd2')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', conv_keys = True, job_id = 'stream0',
+                    device = 'hd0', base_node = 'hd2')
         self.wait_until_completed(drive = 'stream0')
 
         # The chain is hd2 <- hd0 now. hd1 is missing
@@ -1013,8 +959,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         self.reopen(opts, {}, "backing is missing for 'hd0'")
 
         # Now we can delete hd0 (and hd2)
-        result = self.vm.qmp('blockdev-del', conv_keys = True, node_name = 'hd0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', conv_keys = True, node_name = 'hd0')
         self.assertEqual(self.get_node('hd2'), None)
 
     # Reopen the chain during a block-stream job (from hd1 to hd0)
@@ -1023,14 +968,12 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         opts = hd_opts(0)
         opts['backing'] = hd_opts(1)
         opts['backing']['backing'] = hd_opts(2)
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         # hd2 <- hd0
-        result = self.vm.qmp('block-stream', conv_keys = True, job_id = 'stream0',
-                             device = 'hd0', base_node = 'hd2',
-                             auto_finalize = False)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', conv_keys = True, job_id = 'stream0',
+                    device = 'hd0', base_node = 'hd2',
+                    auto_finalize = False)
 
         # We can remove hd2 while the stream job is ongoing
         opts['backing']['backing'] = None
@@ -1048,14 +991,12 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         opts = hd_opts(0)
         opts['backing'] = hd_opts(1)
         opts['backing']['backing'] = hd_opts(2)
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         # hd1 <- hd0
-        result = self.vm.qmp('block-stream', conv_keys = True, job_id = 'stream0',
-                             device = 'hd1', filter_node_name='cor',
-                             auto_finalize = False)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-stream', conv_keys = True, job_id = 'stream0',
+                    device = 'hd1', filter_node_name='cor',
+                    auto_finalize = False)
 
         # We can't reopen with the original options because there is a filter
         # inserted by stream job above hd1.
@@ -1084,12 +1025,10 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         opts = hd_opts(0)
         opts['backing'] = hd_opts(1)
         opts['backing']['backing'] = hd_opts(2)
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
-        result = self.vm.qmp('block-commit', conv_keys = True, job_id = 'commit0',
-                             device = 'hd0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit', conv_keys = True, job_id = 'commit0',
+                    device = 'hd0')
 
         # We can't remove hd2 while the commit job is ongoing
         opts['backing']['backing'] = None
@@ -1104,8 +1043,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         self.assert_qmp(event, 'data/type', 'commit')
         self.assert_qmp_absent(event, 'data/error')
 
-        result = self.vm.qmp('block-job-complete', device='commit0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-complete', device='commit0')
 
         self.wait_until_completed(drive = 'commit0')
 
@@ -1115,13 +1053,11 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         opts = hd_opts(0)
         opts['backing'] = hd_opts(1)
         opts['backing']['backing'] = hd_opts(2)
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
-        result = self.vm.qmp('block-commit', conv_keys = True, job_id = 'commit0',
-                             device = 'hd0', top_node = 'hd1',
-                             auto_finalize = False)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit', conv_keys = True, job_id = 'commit0',
+                    device = 'hd0', top_node = 'hd1',
+                    auto_finalize = False)
 
         # We can't remove hd2 while the commit job is ongoing
         opts['backing']['backing'] = None
@@ -1141,36 +1077,28 @@ class TestBlockdevReopen(iotests.QMPTestCase):
     def run_test_iothreads(self, iothread_a, iothread_b, errmsg = None,
                            opts_a = None, opts_b = None):
         opts = opts_a or hd_opts(0)
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts)
 
         opts2 = opts_b or hd_opts(2)
-        result = self.vm.qmp('blockdev-add', conv_keys = False, **opts2)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', conv_keys = False, **opts2)
 
-        result = self.vm.qmp('object-add', qom_type='iothread', id='iothread0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('object-add', qom_type='iothread', id='iothread0')
 
-        result = self.vm.qmp('object-add', qom_type='iothread', id='iothread1')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('object-add', qom_type='iothread', id='iothread1')
 
-        result = self.vm.qmp('device_add', driver='virtio-scsi', id='scsi0',
-                             iothread=iothread_a)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('device_add', driver='virtio-scsi', id='scsi0',
+                    iothread=iothread_a)
 
-        result = self.vm.qmp('device_add', driver='virtio-scsi', id='scsi1',
-                             iothread=iothread_b)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('device_add', driver='virtio-scsi', id='scsi1',
+                    iothread=iothread_b)
 
         if iothread_a:
-            result = self.vm.qmp('device_add', driver='scsi-hd', drive='hd0',
-                                 share_rw=True, bus="scsi0.0")
-            self.assert_qmp(result, 'return', {})
+            self.vm.cmd('device_add', driver='scsi-hd', drive='hd0',
+                        share_rw=True, bus="scsi0.0")
 
         if iothread_b:
-            result = self.vm.qmp('device_add', driver='scsi-hd', drive='hd2',
-                                 share_rw=True, bus="scsi1.0")
-            self.assert_qmp(result, 'return', {})
+            self.vm.cmd('device_add', driver='scsi-hd', drive='hd2',
+                        share_rw=True, bus="scsi1.0")
 
         # Attaching the backing file may or may not work
         self.reopen(opts, {'backing': 'hd2'}, errmsg)
@@ -1199,8 +1127,7 @@ class TestBlockdevReopen(iotests.QMPTestCase):
         # Create a throttle-group object
         opts = { 'qom-type': 'throttle-group', 'id': 'group0',
                  'limits': { 'iops-total': 1000 } }
-        result = self.vm.qmp('object-add', conv_keys = False, **opts)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('object-add', conv_keys = False, **opts)
 
         # Options with a throttle filter between format and protocol
         opts = [
diff --git a/tests/qemu-iotests/264 b/tests/qemu-iotests/264
index bc431d1a19..67364a05e6 100755
--- a/tests/qemu-iotests/264
+++ b/tests/qemu-iotests/264
@@ -48,18 +48,16 @@ class TestNbdReconnect(iotests.QMPTestCase):
         """Stat job with nbd target and kill the server"""
         assert job in ('blockdev-backup', 'blockdev-mirror')
         with qemu_nbd_popen('-k', nbd_sock, '-f', iotests.imgfmt, disk_b):
-            result = self.vm.qmp('blockdev-add',
-                                 **{'node_name': 'backup0',
-                                    'driver': 'raw',
-                                    'file': {'driver': 'nbd',
-                                             'server': {'type': 'unix',
-                                                        'path': nbd_sock},
-                                             'reconnect-delay': 10}})
-            self.assert_qmp(result, 'return', {})
-            result = self.vm.qmp(job, device='drive0',
-                                 sync='full', target='backup0',
-                                 speed=(1 * 1024 * 1024))
-            self.assert_qmp(result, 'return', {})
+            self.vm.cmd('blockdev-add',
+                        {'node-name': 'backup0',
+                         'driver': 'raw',
+                         'file': {'driver': 'nbd',
+                                  'server': {'type': 'unix',
+                                             'path': nbd_sock},
+                                  'reconnect-delay': 10}})
+            self.vm.cmd(job, device='drive0',
+                        sync='full', target='backup0',
+                        speed=(1 * 1024 * 1024))
 
             # Wait for some progress
             t = 0.0
@@ -77,8 +75,7 @@ class TestNbdReconnect(iotests.QMPTestCase):
         self.assertTrue(jobs)
         self.assertTrue(jobs[0]['offset'] < jobs[0]['len'])
 
-        result = self.vm.qmp('block-job-set-speed', device='drive0', speed=0)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-set-speed', device='drive0', speed=0)
 
         # Emulate server down time for 1 second
         time.sleep(1)
@@ -91,12 +88,10 @@ class TestNbdReconnect(iotests.QMPTestCase):
         with qemu_nbd_popen('-k', nbd_sock, '-f', iotests.imgfmt, disk_b):
             e = self.vm.event_wait('BLOCK_JOB_COMPLETED')
             self.assertEqual(e['data']['offset'], size)
-            result = self.vm.qmp('blockdev-del', node_name='backup0')
-            self.assert_qmp(result, 'return', {})
+            self.vm.cmd('blockdev-del', node_name='backup0')
 
     def cancel_job(self):
-        result = self.vm.qmp('block-job-cancel', device='drive0', force=True)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-cancel', device='drive0', force=True)
 
         start_t = time.time()
         self.vm.event_wait('BLOCK_JOB_CANCELLED')
diff --git a/tests/qemu-iotests/281 b/tests/qemu-iotests/281
index 5e1339bd75..f6746a12e8 100755
--- a/tests/qemu-iotests/281
+++ b/tests/qemu-iotests/281
@@ -56,15 +56,13 @@ class TestDirtyBitmapIOThread(iotests.QMPTestCase):
             os.remove(self.images[name])
 
     def test_add_dirty_bitmap(self):
-        result = self.vm.qmp(
+        self.vm.cmd(
             'block-dirty-bitmap-add',
             node='drive0',
             name='bitmap1',
             persistent=True,
         )
 
-        self.assert_qmp(result, 'return', {})
-
 
 # Test for RHBZ#1746217 & RHBZ#1773517
 class TestNBDMirrorIOThread(iotests.QMPTestCase):
@@ -105,23 +103,21 @@ class TestNBDMirrorIOThread(iotests.QMPTestCase):
             os.remove(self.images[name])
 
     def test_nbd_mirror(self):
-        result = self.vm_tgt.qmp(
+        self.vm_tgt.cmd(
             'nbd-server-start',
             addr={
                 'type': 'unix',
                 'data': { 'path': self.nbd_sock }
             }
         )
-        self.assert_qmp(result, 'return', {})
 
-        result = self.vm_tgt.qmp(
+        self.vm_tgt.cmd(
             'nbd-server-add',
             device='drive0',
             writable=True
         )
-        self.assert_qmp(result, 'return', {})
 
-        result = self.vm_src.qmp(
+        self.vm_src.cmd(
             'drive-mirror',
             device='drive0',
             target='nbd+unix:///drive0?socket=' + self.nbd_sock,
@@ -130,7 +126,6 @@ class TestNBDMirrorIOThread(iotests.QMPTestCase):
             speed=64*1024*1024,
             job_id='j1'
         )
-        self.assert_qmp(result, 'return', {})
 
         self.vm_src.event_wait(name="BLOCK_JOB_READY")
 
@@ -290,8 +285,7 @@ class TestYieldingAndTimers(iotests.QMPTestCase):
         # they will remain active, fire later, and then access freed data.
         # (Or, with "block/nbd: Assert there are no timers when closed"
         # applied, the assertions added in that patch will fail.)
-        result = self.vm.qmp('blockdev-del', node_name='nbd')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', node_name='nbd')
 
         # Give the timers some time to fire (both have a timeout of 1 s).
         # (Sleeping in an iotest may ring some alarm bells, but note that if
@@ -303,9 +297,8 @@ class TestYieldingAndTimers(iotests.QMPTestCase):
     def test_yield_in_iothread(self):
         # Move the NBD node to the I/O thread; the NBD block driver should
         # attach the connection's QIOChannel to that thread's AioContext, too
-        result = self.vm.qmp('x-blockdev-set-iothread',
-                             node_name='nbd', iothread='iothr')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('x-blockdev-set-iothread',
+                    node_name='nbd', iothread='iothr')
 
         # Do some I/O that will be throttled by the QSD, so that the network
         # connection hopefully will yield here.  When it is resumed, it must
diff --git a/tests/qemu-iotests/295 b/tests/qemu-iotests/295
index 270ad3999f..2d472c9447 100755
--- a/tests/qemu-iotests/295
+++ b/tests/qemu-iotests/295
@@ -57,8 +57,7 @@ class EncryptionSetupTestCase(iotests.QMPTestCase):
         # create the secrets and load 'em into the VM
         self.secrets = [ Secret(i) for i in range(0, 6) ]
         for secret in self.secrets:
-            result = self.vm.qmp("object-add", **secret.to_qmp_object())
-            self.assert_qmp(result, 'return', {})
+            self.vm.cmd("object-add", **secret.to_qmp_object())
 
         if iotests.imgfmt == "qcow2":
             self.pfx = "encrypt."
@@ -102,26 +101,22 @@ class EncryptionSetupTestCase(iotests.QMPTestCase):
                 }
             }
 
-        result = self.vm.qmp('blockdev-add', **
-            {
-                'driver': iotests.imgfmt,
-                'node-name': id,
-                'read-only': read_only,
+        self.vm.cmd('blockdev-add', {
+            'driver': iotests.imgfmt,
+            'node-name': id,
+            'read-only': read_only,
 
-                **encrypt_options,
+            **encrypt_options,
 
-                'file': {
-                    'driver': 'file',
-                    'filename': test_img,
-                }
+            'file': {
+                'driver': 'file',
+                'filename': test_img,
             }
-        )
-        self.assert_qmp(result, 'return', {})
+        })
 
     # close the encrypted block device
     def closeImageQmp(self, id):
-        result = self.vm.qmp('blockdev-del', **{ 'node-name': id })
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-del', **{ 'node-name': id })
 
     ###########################################################################
     # add a key to an encrypted block device
diff --git a/tests/qemu-iotests/296 b/tests/qemu-iotests/296
index 0d21b740a7..75a8695cfa 100755
--- a/tests/qemu-iotests/296
+++ b/tests/qemu-iotests/296
@@ -61,10 +61,8 @@ class EncryptionSetupTestCase(iotests.QMPTestCase):
         # create the secrets and load 'em into the VMs
         self.secrets = [ Secret(i) for i in range(0, 4) ]
         for secret in self.secrets:
-            result = self.vm1.qmp("object-add", **secret.to_qmp_object())
-            self.assert_qmp(result, 'return', {})
-            result = self.vm2.qmp("object-add", **secret.to_qmp_object())
-            self.assert_qmp(result, 'return', {})
+            self.vm1.cmd("object-add", **secret.to_qmp_object())
+            self.vm2.cmd("object-add", **secret.to_qmp_object())
 
     # test case shutdown
     def tearDown(self):
@@ -132,10 +130,9 @@ class EncryptionSetupTestCase(iotests.QMPTestCase):
             }
 
         if reOpen:
-            result = vm.qmp(command, options=[opts])
+            vm.cmd(command, options=[opts])
         else:
-            result = vm.qmp(command, **opts)
-        self.assert_qmp(result, 'return', {})
+            vm.cmd(command, **opts)
 
 
     ###########################################################################
@@ -154,8 +151,7 @@ class EncryptionSetupTestCase(iotests.QMPTestCase):
 
     # close the encrypted block device
     def closeImageQmp(self, vm, id):
-        result = vm.qmp('blockdev-del', **{ 'node-name': id })
-        self.assert_qmp(result, 'return', {})
+        vm.cmd('blockdev-del', **{ 'node-name': id })
 
     ###########################################################################
 
diff --git a/tests/qemu-iotests/298 b/tests/qemu-iotests/298
index fae72211b1..c43c6586d3 100755
--- a/tests/qemu-iotests/298
+++ b/tests/qemu-iotests/298
@@ -80,25 +80,23 @@ class TestPreallocateFilter(TestPreallocateBase):
     def test_external_snapshot(self):
         self.test_prealloc()
 
-        result = self.vm.qmp('blockdev-snapshot-sync', node_name='disk',
-                             snapshot_file=overlay,
-                             snapshot_node_name='overlay')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-snapshot-sync', node_name='disk',
+                    snapshot_file=overlay,
+                    snapshot_node_name='overlay')
 
         # on reopen to  r-o base preallocation should be dropped
         self.check_small()
 
         self.vm.hmp_qemu_io('drive0', 'write 1M 1M')
 
-        result = self.vm.qmp('block-commit', device='overlay')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-commit', device='overlay')
         self.complete_and_wait()
 
         # commit of new megabyte should trigger preallocation
         self.check_big()
 
     def test_reopen_opts(self):
-        result = self.vm.qmp('blockdev-reopen', options=[{
+        self.vm.cmd('blockdev-reopen', options=[{
             'node-name': 'disk',
             'driver': iotests.imgfmt,
             'file': {
@@ -113,7 +111,6 @@ class TestPreallocateFilter(TestPreallocateBase):
                 }
             }
         }])
-        self.assert_qmp(result, 'return', {})
 
         self.vm.hmp_qemu_io('drive0', 'write 0 1M')
         self.assertTrue(os.path.getsize(disk) == 25 * MiB)
diff --git a/tests/qemu-iotests/300 b/tests/qemu-iotests/300
index dbd28384ec..7b479ab01e 100755
--- a/tests/qemu-iotests/300
+++ b/tests/qemu-iotests/300
@@ -50,10 +50,9 @@ class TestDirtyBitmapMigration(iotests.QMPTestCase):
         self.vm_b.add_incoming(f'unix:{mig_sock}')
         self.vm_b.launch()
 
-        result = self.vm_a.qmp('block-dirty-bitmap-add',
-                               node=self.src_node_name,
-                               name=self.src_bmap_name)
-        self.assert_qmp(result, 'return', {})
+        self.vm_a.cmd('block-dirty-bitmap-add',
+                      node=self.src_node_name,
+                      name=self.src_bmap_name)
 
         # Dirty some random megabytes
         for _ in range(9):
@@ -69,8 +68,7 @@ class TestDirtyBitmapMigration(iotests.QMPTestCase):
                 for name in ('dirty-bitmaps', 'events')]
 
         for vm in (self.vm_a, self.vm_b):
-            result = vm.qmp('migrate-set-capabilities', capabilities=caps)
-            self.assert_qmp(result, 'return', {})
+            vm.cmd('migrate-set-capabilities', capabilities=caps)
 
     def tearDown(self) -> None:
         self.vm_a.shutdown()
@@ -93,8 +91,7 @@ class TestDirtyBitmapMigration(iotests.QMPTestCase):
 
     def migrate(self, bitmap_name_valid: bool = True,
                 migration_success: bool = True) -> None:
-        result = self.vm_a.qmp('migrate', uri=f'unix:{mig_sock}')
-        self.assert_qmp(result, 'return', {})
+        self.vm_a.cmd('migrate', uri=f'unix:{mig_sock}')
 
         with iotests.Timeout(5, 'Timeout waiting for migration to complete'):
             self.assertEqual(self.vm_a.wait_migration('postmigrate'),
@@ -442,10 +439,9 @@ class TestBlockBitmapMappingErrors(TestDirtyBitmapMigration):
     def test_bitmap_name_too_long(self) -> None:
         name = 'a' * 256
 
-        result = self.vm_a.qmp('block-dirty-bitmap-add',
-                               node=self.src_node_name,
-                               name=name)
-        self.assert_qmp(result, 'return', {})
+        self.vm_a.cmd('block-dirty-bitmap-add',
+                      node=self.src_node_name,
+                      name=name)
 
         self.migrate(False, False)
 
@@ -517,22 +513,16 @@ class TestCrossAliasMigration(TestDirtyBitmapMigration):
         TestDirtyBitmapMigration.setUp(self)
 
         # Now create another block device and let both have two bitmaps each
-        result = self.vm_a.qmp('blockdev-add',
-                               node_name='node-b', driver='null-co')
-        self.assert_qmp(result, 'return', {})
+        self.vm_a.cmd('blockdev-add', node_name='node-b', driver='null-co')
 
-        result = self.vm_b.qmp('blockdev-add',
-                               node_name='node-a', driver='null-co')
-        self.assert_qmp(result, 'return', {})
+        self.vm_b.cmd('blockdev-add', node_name='node-a', driver='null-co')
 
         bmaps_to_add = (('node-a', 'bmap-b'),
                         ('node-b', 'bmap-a'),
                         ('node-b', 'bmap-b'))
 
         for (node, bmap) in bmaps_to_add:
-            result = self.vm_a.qmp('block-dirty-bitmap-add',
-                                   node=node, name=bmap)
-            self.assert_qmp(result, 'return', {})
+            self.vm_a.cmd('block-dirty-bitmap-add', node=node, name=bmap)
 
     @staticmethod
     def cross_mapping() -> BlockBitmapMapping:
@@ -611,24 +601,20 @@ class TestAliasTransformMigration(TestDirtyBitmapMigration):
         TestDirtyBitmapMigration.setUp(self)
 
         # Now create another block device and let both have two bitmaps each
-        result = self.vm_a.qmp('blockdev-add',
-                               node_name='node-b', driver='null-co',
-                               read_zeroes=False)
-        self.assert_qmp(result, 'return', {})
+        self.vm_a.cmd('blockdev-add',
+                      node_name='node-b', driver='null-co',
+                      read_zeroes=False)
 
-        result = self.vm_b.qmp('blockdev-add',
-                               node_name='node-a', driver='null-co',
-                               read_zeroes=False)
-        self.assert_qmp(result, 'return', {})
+        self.vm_b.cmd('blockdev-add',
+                      node_name='node-a', driver='null-co',
+                      read_zeroes=False)
 
         bmaps_to_add = (('node-a', 'bmap-b'),
                         ('node-b', 'bmap-a'),
                         ('node-b', 'bmap-b'))
 
         for (node, bmap) in bmaps_to_add:
-            result = self.vm_a.qmp('block-dirty-bitmap-add',
-                                   node=node, name=bmap)
-            self.assert_qmp(result, 'return', {})
+            self.vm_a.cmd('block-dirty-bitmap-add', node=node, name=bmap)
 
     @staticmethod
     def transform_mapping() -> BlockBitmapMapping:
diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
index 87eb5f542f..e4777dcd9f 100644
--- a/tests/qemu-iotests/iotests.py
+++ b/tests/qemu-iotests/iotests.py
@@ -1232,8 +1232,7 @@ def assert_json_filename_equal(self, json_filename, reference):
     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', {})
+        self.vm.cmd('block-job-cancel', device=drive, force=force)
 
         if resume:
             self.vm.resume_drive(drive)
@@ -1295,8 +1294,7 @@ def complete_and_wait(self, drive='drive0', wait_ready=True,
         if wait_ready:
             self.wait_ready(drive=drive)
 
-        result = self.vm.qmp('block-job-complete', device=drive)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-complete', device=drive)
 
         event = self.wait_until_completed(drive=drive, error=completion_error)
         self.assertTrue(event['data']['type'] in ['mirror', 'commit'])
diff --git a/tests/qemu-iotests/tests/migrate-bitmaps-postcopy-test b/tests/qemu-iotests/tests/migrate-bitmaps-postcopy-test
index fc9c4b4ef4..2c33420151 100755
--- a/tests/qemu-iotests/tests/migrate-bitmaps-postcopy-test
+++ b/tests/qemu-iotests/tests/migrate-bitmaps-postcopy-test
@@ -118,11 +118,10 @@ class TestDirtyBitmapPostcopyMigration(iotests.QMPTestCase):
     def start_postcopy(self):
         """ Run migration until RESUME event on target. Return this event. """
         for i in range(nb_bitmaps):
-            result = self.vm_a.qmp('block-dirty-bitmap-add', node='drive0',
-                                   name='bitmap{}'.format(i),
-                                   granularity=granularity,
-                                   persistent=True)
-            self.assert_qmp(result, 'return', {})
+            self.vm_a.cmd('block-dirty-bitmap-add', node='drive0',
+                          name='bitmap{}'.format(i),
+                          granularity=granularity,
+                          persistent=True)
 
         result = self.vm_a.qmp('x-debug-block-dirty-bitmap-sha256',
                                node='drive0', name='bitmap0')
@@ -140,9 +139,8 @@ class TestDirtyBitmapPostcopyMigration(iotests.QMPTestCase):
         # We want to calculate resulting sha256. Do it in bitmap0, so, disable
         # other bitmaps
         for i in range(1, nb_bitmaps):
-            result = self.vm_a.qmp('block-dirty-bitmap-disable', node='drive0',
-                                   name='bitmap{}'.format(i))
-            self.assert_qmp(result, 'return', {})
+            self.vm_a.cmd('block-dirty-bitmap-disable', node='drive0',
+                          name='bitmap{}'.format(i))
 
         apply_discards(self.vm_a, discards2)
 
@@ -152,24 +150,19 @@ class TestDirtyBitmapPostcopyMigration(iotests.QMPTestCase):
 
         # Now, enable some bitmaps, to be updated during migration
         for i in range(2, nb_bitmaps, 2):
-            result = self.vm_a.qmp('block-dirty-bitmap-enable', node='drive0',
-                                   name='bitmap{}'.format(i))
-            self.assert_qmp(result, 'return', {})
+            self.vm_a.cmd('block-dirty-bitmap-enable', node='drive0',
+                          name='bitmap{}'.format(i))
 
         caps = [{'capability': 'dirty-bitmaps', 'state': True},
                 {'capability': 'events', 'state': True}]
 
-        result = self.vm_a.qmp('migrate-set-capabilities', capabilities=caps)
-        self.assert_qmp(result, 'return', {})
+        self.vm_a.cmd('migrate-set-capabilities', capabilities=caps)
 
-        result = self.vm_b.qmp('migrate-set-capabilities', capabilities=caps)
-        self.assert_qmp(result, 'return', {})
+        self.vm_b.cmd('migrate-set-capabilities', capabilities=caps)
 
-        result = self.vm_a.qmp('migrate', uri='exec:cat>' + fifo)
-        self.assert_qmp(result, 'return', {})
+        self.vm_a.cmd('migrate', uri='exec:cat>' + fifo)
 
-        result = self.vm_a.qmp('migrate-start-postcopy')
-        self.assert_qmp(result, 'return', {})
+        self.vm_a.cmd('migrate-start-postcopy')
 
         event_resume = self.vm_b.event_wait('RESUME')
         self.vm_b_events.append(event_resume)
diff --git a/tests/qemu-iotests/tests/migrate-bitmaps-test b/tests/qemu-iotests/tests/migrate-bitmaps-test
index 59f3357580..b5b03c0377 100755
--- a/tests/qemu-iotests/tests/migrate-bitmaps-test
+++ b/tests/qemu-iotests/tests/migrate-bitmaps-test
@@ -67,8 +67,7 @@ class TestDirtyBitmapMigration(iotests.QMPTestCase):
         if persistent:
             params['persistent'] = True
 
-        result = vm.qmp('block-dirty-bitmap-add', **params)
-        self.assert_qmp(result, 'return', {})
+        vm.cmd('block-dirty-bitmap-add', **params)
 
     def check_bitmap(self, vm, sha256):
         result = vm.qmp('x-debug-block-dirty-bitmap-sha256',
@@ -91,9 +90,7 @@ class TestDirtyBitmapMigration(iotests.QMPTestCase):
         if migrate_bitmaps:
             mig_caps.append({'capability': 'dirty-bitmaps', 'state': True})
 
-        result = self.vm_a.qmp('migrate-set-capabilities',
-                               capabilities=mig_caps)
-        self.assert_qmp(result, 'return', {})
+        self.vm_a.cmd('migrate-set-capabilities', capabilities=mig_caps)
 
         self.add_bitmap(self.vm_a, granularity, persistent)
         for r in regions:
@@ -114,8 +111,7 @@ class TestDirtyBitmapMigration(iotests.QMPTestCase):
         removed = (not migrate_bitmaps) and persistent
         self.check_bitmap(self.vm_a, False if removed else sha256)
 
-        result = self.vm_a.qmp('cont')
-        self.assert_qmp(result, 'return', {})
+        self.vm_a.cmd('cont')
 
         # test that bitmap is still here after invalidation
         self.check_bitmap(self.vm_a, sha256)
@@ -158,9 +154,7 @@ class TestDirtyBitmapMigration(iotests.QMPTestCase):
         if online:
             os.mkfifo(mig_file)
             self.vm_b.launch()
-            result = self.vm_b.qmp('migrate-set-capabilities',
-                                   capabilities=mig_caps)
-            self.assert_qmp(result, 'return', {})
+            self.vm_b.cmd('migrate-set-capabilities', capabilities=mig_caps)
 
         self.add_bitmap(self.vm_a, granularity, persistent)
         for r in regions:
@@ -171,9 +165,7 @@ class TestDirtyBitmapMigration(iotests.QMPTestCase):
             self.vm_a.shutdown()
             self.vm_a.launch()
 
-        result = self.vm_a.qmp('migrate-set-capabilities',
-                               capabilities=mig_caps)
-        self.assert_qmp(result, 'return', {})
+        self.vm_a.cmd('migrate-set-capabilities', capabilities=mig_caps)
 
         result = self.vm_a.qmp('migrate', uri=mig_cmd)
         while True:
@@ -184,11 +176,8 @@ class TestDirtyBitmapMigration(iotests.QMPTestCase):
         if not online:
             self.vm_a.shutdown()
             self.vm_b.launch()
-            result = self.vm_b.qmp('migrate-set-capabilities',
-                                   capabilities=mig_caps)
-            self.assert_qmp(result, 'return', {})
-            result = self.vm_b.qmp('migrate-incoming', uri=incoming_cmd)
-            self.assert_qmp(result, 'return', {})
+            self.vm_b.cmd('migrate-set-capabilities', capabilities=mig_caps)
+            self.vm_b.cmd('migrate-incoming', uri=incoming_cmd)
 
         while True:
             event = self.vm_b.event_wait('MIGRATION')
@@ -254,8 +243,7 @@ class TestDirtyBitmapBackingMigration(iotests.QMPTestCase):
         self.vm = iotests.VM()
         self.vm.launch()
 
-        result = self.vm.qmp('blockdev-add', **blockdev)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-add', **blockdev)
 
         # Check that the bitmaps are there
         nodes = self.vm.qmp('query-named-block-nodes', flat=True)['return']
@@ -264,8 +252,7 @@ class TestDirtyBitmapBackingMigration(iotests.QMPTestCase):
                 self.assert_qmp(node, 'dirty-bitmaps[0]/name', 'bmap0')
 
         caps = [{'capability': 'events', 'state': True}]
-        result = self.vm.qmp('migrate-set-capabilities', capabilities=caps)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('migrate-set-capabilities', capabilities=caps)
 
     def tearDown(self):
         self.vm.shutdown()
@@ -276,14 +263,12 @@ class TestDirtyBitmapBackingMigration(iotests.QMPTestCase):
         """
         Continue the source after migration.
         """
-        result = self.vm.qmp('migrate', uri='exec: cat > /dev/null')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('migrate', uri='exec: cat > /dev/null')
 
         with Timeout(10, 'Migration timeout'):
             self.vm.wait_migration('postmigrate')
 
-        result = self.vm.qmp('cont')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('cont')
 
 
 def main() -> None:
diff --git a/tests/qemu-iotests/tests/migrate-during-backup b/tests/qemu-iotests/tests/migrate-during-backup
index 34103229ee..0645b8a718 100755
--- a/tests/qemu-iotests/tests/migrate-during-backup
+++ b/tests/qemu-iotests/tests/migrate-during-backup
@@ -43,7 +43,7 @@ class TestMigrateDuringBackup(iotests.QMPTestCase):
 
         self.vm = iotests.VM().add_drive(disk_a)
         self.vm.launch()
-        result = self.vm.qmp('blockdev-add', {
+        self.vm.cmd('blockdev-add', {
             'node-name': 'target',
             'driver': iotests.imgfmt,
             'file': {
@@ -51,26 +51,21 @@ class TestMigrateDuringBackup(iotests.QMPTestCase):
                 'filename': disk_b
             }
         })
-        self.assert_qmp(result, 'return', {})
 
     def test_migrate(self):
-        result = self.vm.qmp('blockdev-backup', device='drive0',
-                             target='target', sync='full',
-                             speed=1, x_perf={
-                                 'max-workers': 1,
-                                 'max-chunk': 64 * 1024
-                             })
-        self.assert_qmp(result, 'return', {})
-
-        result = self.vm.qmp('job-pause', id='drive0')
-        self.assert_qmp(result, 'return', {})
-
-        result = self.vm.qmp('migrate-set-capabilities',
-                             capabilities=[{'capability': 'events',
-                                            'state': True}])
-        self.assert_qmp(result, 'return', {})
-        result = self.vm.qmp('migrate', uri=mig_cmd)
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-backup', device='drive0',
+                    target='target', sync='full',
+                    speed=1, x_perf={
+                        'max-workers': 1,
+                        'max-chunk': 64 * 1024
+                    })
+
+        self.vm.cmd('job-pause', id='drive0')
+
+        self.vm.cmd('migrate-set-capabilities',
+                    capabilities=[{'capability': 'events',
+                                   'state': True}])
+        self.vm.cmd('migrate', uri=mig_cmd)
 
         e = self.vm.events_wait((('MIGRATION',
                                   {'data': {'status': 'completed'}}),
@@ -80,11 +75,8 @@ class TestMigrateDuringBackup(iotests.QMPTestCase):
         # Don't assert that e is 'failed' now: this way we'll miss
         # possible crash when backup continues :)
 
-        result = self.vm.qmp('block-job-set-speed', device='drive0',
-                             speed=0)
-        self.assert_qmp(result, 'return', {})
-        result = self.vm.qmp('job-resume', id='drive0')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-set-speed', device='drive0', speed=0)
+        self.vm.cmd('job-resume', id='drive0')
 
         # For future: if something changes so that both migration
         # and backup pass, let's not miss that moment, as it may
diff --git a/tests/qemu-iotests/tests/migration-permissions b/tests/qemu-iotests/tests/migration-permissions
index 6be02581c7..04212e8cc8 100755
--- a/tests/qemu-iotests/tests/migration-permissions
+++ b/tests/qemu-iotests/tests/migration-permissions
@@ -45,11 +45,10 @@ class TestMigrationPermissions(iotests.QMPTestCase):
 
             vms[i].launch()
 
-            result = vms[i].qmp('migrate-set-capabilities',
-                                capabilities=[
-                                    {'capability': 'events', 'state': True}
-                                ])
-            self.assert_qmp(result, 'return', {})
+            vms[i].cmd('migrate-set-capabilities',
+                       capabilities=[
+                           {'capability': 'events', 'state': True}
+                       ])
 
         self.vm_s = vms[0]
         self.vm_d = vms[1]
diff --git a/tests/qemu-iotests/tests/mirror-top-perms b/tests/qemu-iotests/tests/mirror-top-perms
index 8bca592708..0e41504163 100755
--- a/tests/qemu-iotests/tests/mirror-top-perms
+++ b/tests/qemu-iotests/tests/mirror-top-perms
@@ -78,12 +78,11 @@ class TestMirrorTopPerms(iotests.QMPTestCase):
         difficult to let some other qemu process open the image.)
         """
 
-        result = self.vm.qmp('blockdev-mirror',
-                             job_id='mirror',
-                             device='drive0',
-                             target='null',
-                             sync='full')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('blockdev-mirror',
+                    job_id='mirror',
+                    device='drive0',
+                    target='null',
+                    sync='full')
 
         self.vm.event_wait('BLOCK_JOB_READY')
 
@@ -105,9 +104,7 @@ class TestMirrorTopPerms(iotests.QMPTestCase):
         except machine.VMLaunchFailure as exc:
             assert 'Is another process using the image' in exc.output
 
-        result = self.vm.qmp('block-job-cancel',
-                             device='mirror')
-        self.assert_qmp(result, 'return', {})
+        self.vm.cmd('block-job-cancel', device='mirror')
 
         self.vm.event_wait('BLOCK_JOB_COMPLETED')
 
-- 
2.35.1

Re: [PATCH 2/2] iotests: use vm.cmd() instead of vm.qmp() where appropriate

[Eric Blake]

On Fri, Apr 08, 2022 at 08:02:14PM +0300, Vladimir Sementsov-Ogievskiy wrote:
> Checking success by hand every time is tedious. Let's use cmd() method
> instead which does this check for us.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@openvz.org>
> ---
>  31 files changed, 773 insertions(+), 1205 deletions(-)

Big, but mechanical.

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

Re: [RFC 0/2] introduce QEMUMachind.cmd()

[John Snow]

On Fri, Apr 8, 2022 at 1:02 PM Vladimir Sementsov-Ogievskiy
<vladimir.sementsov-ogievskiy@openvz.org> wrote:
>
> Hi all!
>
> I always dreamed about getting rid of pattern
>
>     result = self.vm.qmp(...)
>     self.assert_qmp(result, 'return', {})
>
> Here is a suggestion to switch to
>
>     self.vm.cmd(...)
>
> pattern instead.

Yeah, I am absolutely on board for this!

>
> I'm not sure we really want to update so many tests. May be just commit
> patch 01, and use new interface for new code. On the other hand, old
> code always used as an example to write the new one.

I think it's worth updating all the old tests ... especially if you've
already done it here. We could even do something like what I did with
qemu_img() and qemu_io() and have the uncaught exception print a bunch
of information to the screen to help make it extremely obvious as to
what failed and why.

If you can rebase this, I'd love to review it more carefully - it
aligns with my own selfish goals and interests :) The Python branch
was merged recently and so we should be all set.

>
> The series is based on John's python branch.
>
> Vladimir Sementsov-Ogievskiy (2):
>   python/machine.py: upgrade vm.command() method
>   iotests: use vm.cmd() instead of vm.qmp() where appropriate
>
>  python/qemu/machine/machine.py                |  16 +-
>  tests/qemu-iotests/030                        | 168 +++----
>  tests/qemu-iotests/040                        | 167 +++---
>  tests/qemu-iotests/041                        | 474 ++++++++----------
>  tests/qemu-iotests/045                        |  15 +-
>  tests/qemu-iotests/055                        |  61 +--
>  tests/qemu-iotests/056                        |  23 +-
>  tests/qemu-iotests/093                        |  41 +-
>  tests/qemu-iotests/118                        | 221 ++++----
>  tests/qemu-iotests/124                        |  69 ++-
>  tests/qemu-iotests/129                        |  13 +-
>  tests/qemu-iotests/132                        |   5 +-
>  tests/qemu-iotests/139                        |  43 +-
>  tests/qemu-iotests/147                        |  30 +-
>  tests/qemu-iotests/151                        |  40 +-
>  tests/qemu-iotests/155                        |  53 +-
>  tests/qemu-iotests/165                        |   7 +-
>  tests/qemu-iotests/196                        |   3 +-
>  tests/qemu-iotests/205                        |   6 +-
>  tests/qemu-iotests/245                        | 245 ++++-----
>  tests/qemu-iotests/256                        |  34 +-
>  tests/qemu-iotests/257                        |  36 +-
>  tests/qemu-iotests/264                        |  31 +-
>  tests/qemu-iotests/281                        |  21 +-
>  tests/qemu-iotests/295                        |  27 +-
>  tests/qemu-iotests/296                        |  14 +-
>  tests/qemu-iotests/298                        |  13 +-
>  tests/qemu-iotests/300                        |  50 +-
>  tests/qemu-iotests/iotests.py                 |   6 +-
>  .../tests/migrate-bitmaps-postcopy-test       |  31 +-
>  tests/qemu-iotests/tests/migrate-bitmaps-test |  37 +-
>  .../qemu-iotests/tests/migrate-during-backup  |  40 +-
>  .../qemu-iotests/tests/migration-permissions  |   9 +-
>  tests/qemu-iotests/tests/mirror-top-perms     |  15 +-
>  34 files changed, 821 insertions(+), 1243 deletions(-)

Is there anything missing, to your knowledge?

--js

Re: [RFC 0/2] introduce QEMUMachind.cmd()

[Vladimir Sementsov-Ogievskiy]

27.04.2022 22:29, John Snow wrote:
> On Fri, Apr 8, 2022 at 1:02 PM Vladimir Sementsov-Ogievskiy
> <vladimir.sementsov-ogievskiy@openvz.org> wrote:
>>
>> Hi all!
>>
>> I always dreamed about getting rid of pattern
>>
>>      result = self.vm.qmp(...)
>>      self.assert_qmp(result, 'return', {})
>>
>> Here is a suggestion to switch to
>>
>>      self.vm.cmd(...)
>>
>> pattern instead.
> 
> Yeah, I am absolutely on board for this!
> 
>>
>> I'm not sure we really want to update so many tests. May be just commit
>> patch 01, and use new interface for new code. On the other hand, old
>> code always used as an example to write the new one.
> 
> I think it's worth updating all the old tests ... especially if you've
> already done it here. We could even do something like what I did with
> qemu_img() and qemu_io() and have the uncaught exception print a bunch
> of information to the screen to help make it extremely obvious as to
> what failed and why.
> 
> If you can rebase this, I'd love to review it more carefully - it
> aligns with my own selfish goals and interests :) The Python branch
> was merged recently and so we should be all set.
> 
>>
>> The series is based on John's python branch.
>>
>> Vladimir Sementsov-Ogievskiy (2):
>>    python/machine.py: upgrade vm.command() method
>>    iotests: use vm.cmd() instead of vm.qmp() where appropriate
>>
>>   python/qemu/machine/machine.py                |  16 +-
>>   tests/qemu-iotests/030                        | 168 +++----
>>   tests/qemu-iotests/040                        | 167 +++---
>>   tests/qemu-iotests/041                        | 474 ++++++++----------
>>   tests/qemu-iotests/045                        |  15 +-
>>   tests/qemu-iotests/055                        |  61 +--
>>   tests/qemu-iotests/056                        |  23 +-
>>   tests/qemu-iotests/093                        |  41 +-
>>   tests/qemu-iotests/118                        | 221 ++++----
>>   tests/qemu-iotests/124                        |  69 ++-
>>   tests/qemu-iotests/129                        |  13 +-
>>   tests/qemu-iotests/132                        |   5 +-
>>   tests/qemu-iotests/139                        |  43 +-
>>   tests/qemu-iotests/147                        |  30 +-
>>   tests/qemu-iotests/151                        |  40 +-
>>   tests/qemu-iotests/155                        |  53 +-
>>   tests/qemu-iotests/165                        |   7 +-
>>   tests/qemu-iotests/196                        |   3 +-
>>   tests/qemu-iotests/205                        |   6 +-
>>   tests/qemu-iotests/245                        | 245 ++++-----
>>   tests/qemu-iotests/256                        |  34 +-
>>   tests/qemu-iotests/257                        |  36 +-
>>   tests/qemu-iotests/264                        |  31 +-
>>   tests/qemu-iotests/281                        |  21 +-
>>   tests/qemu-iotests/295                        |  27 +-
>>   tests/qemu-iotests/296                        |  14 +-
>>   tests/qemu-iotests/298                        |  13 +-
>>   tests/qemu-iotests/300                        |  50 +-
>>   tests/qemu-iotests/iotests.py                 |   6 +-
>>   .../tests/migrate-bitmaps-postcopy-test       |  31 +-
>>   tests/qemu-iotests/tests/migrate-bitmaps-test |  37 +-
>>   .../qemu-iotests/tests/migrate-during-backup  |  40 +-
>>   .../qemu-iotests/tests/migration-permissions  |   9 +-
>>   tests/qemu-iotests/tests/mirror-top-perms     |  15 +-
>>   34 files changed, 821 insertions(+), 1243 deletions(-)
> 
> Is there anything missing, to your knowledge?
> 

Don't remember) I hope, I'd write in commit message, if there was something :) Will rebase soon.

-- 
Best regards,
Vladimir