qobject_to_json() and qobject_to_json_pretty() build a GString, then
covert it to QString.  Just one of the callers actually needs a
QString: qemu_rbd_parse_filename().  A few others need a string they
can modify: qmp_send_response(), qga's send_response(), to_json_str(),
and qmp_fd_vsend_fds().  The remainder just need a string.

Change qobject_to_json() and qobject_to_json_pretty() to return the
GString.

qemu_rbd_parse_filename() now has to convert to QString.  All others
save a QString temporary.  to_json_str() actually becomes a bit
simpler, because GString provides more convenient modification
functions.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201211171152.146877-6-armbru@redhat.com>

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20201211171152.146877-4-armbru@redhat.com>

Commit e8c9e658 "qom: Make "info qom-tree" show children sorted"
sorts children the simple, stupid, quadratic way.  I thought the
number of children would be small enough for this not to matter.  I
was wrong: there are outliers with several hundred children, e.g ARM
machines nuri and smdkc210 each have a node with 513 children.

While n^2 sorting isn't noticeable in normal, human usage even for
n=513, it can be quite noticeable in certain automated tests.  In
particular, the sort made device-introspect-test even slower.  Commit
3e7b80f8 "tests: improve performance of device-introspect-test" just
fixed that by cutting back its excessive use of "info qom-tree".
Sorting more efficiently makes sense regardless, so do it.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200714160202.3121879-6-armbru@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

object_get_canonical_path_component() returns a malloced copy of a
property name on success, null on failure.

19 of its 25 callers immediately free the returned copy.

Change object_get_canonical_path_component() to return the property
name directly.  Since modifying the name would be wrong, adjust the
return type to const char *.

Drop the free from the 19 callers become simpler, add the g_strdup()
to the other six.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200714160202.3121879-4-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>

Commit e8c9e658 "qom: Make "info qom-tree" show children sorted"
created a memory leak, because I didn't realize
object_get_canonical_path_component()'s value needs to be freed.

Reproducer:

    $ qemu-system-x86_64 -nodefaults -display none -S -monitor stdio
    QEMU 5.0.50 monitor - type 'help' for more information
    (qemu) info qom-tree

This leaks some 4500 path components, 12-13 characters on average,
i.e. roughly 100kBytes depending on the allocator.  A couple of
hundred "info qom-tree" here, a couple of hundred there, and soon
enough we're talking about real memory.

Plug the leak.

Fixes: e8c9e658
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reported-by: Reviewed-by: Li Qiang <liq3ea@gmail.com> [sent same patch]
Message-Id: <20200714160202.3121879-3-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>

The object_property_set_FOO() setters take property name and value in
an unusual order:

    void object_property_set_FOO(Object *obj, FOO_TYPE value,
                                 const char *name, Error **errp)

Having to pass value before name feels grating.  Swap them.

Same for object_property_set(), object_property_get(), and
object_property_parse().

Convert callers with this Coccinelle script:

    @@
    identifier fun = {
        object_property_get, object_property_parse, object_property_set_str,
        object_property_set_link, object_property_set_bool,
        object_property_set_int, object_property_set_uint, object_property_set,
        object_property_set_qobject
    };
    expression obj, v, name, errp;
    @@
    -    fun(obj, v, name, errp)
    +    fun(obj, name, v, errp)

Chokes on hw/arm/musicpal.c's lcd_refresh() with the unhelpful error
message "no position information".  Convert that one manually.

Fails to convert hw/arm/armsse.c, because Coccinelle gets confused by
ARMSSE being used both as typedef and function-like macro there.
Convert manually.

Fails to convert hw/rx/rx-gdbsim.c, because Coccinelle gets confused
by RXCPU being used both as typedef and function-like macro there.
Convert manually.  The other files using RXCPU that way don't need
conversion.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Message-Id: <20200707160613.848843-27-armbru@redhat.com>
[Straightforwad conflict with commit 2336172d "audio: set default
value for pcspk.iobase property" resolved]

Commit 7d2ef6dc ("hmp: Simplify qom-set") switched to the json
parser, making it possible to specify complex types. However, with this
change it is no longer possible to specify proper sizes (e.g., 2G, 128M),
turning the interface harder to use for properties that consume sizes.

Let's switch back to the previous handling and allow to specify passing
json via the "-j" parameter.

Cc: Philippe Mathieu-Daudé <philmd@redhat.com>
Cc: Markus Armbruster <armbru@redhat.com>
Cc: Dr. David Alan Gilbert <dgilbert@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Daniel P. Berrangé" <berrange@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200610075153.33892-1-david@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

'obj' forgot to free at the end of hmp_qom_get(). Fix that.

The leak stack:
Direct leak of 40 byte(s) in 1 object(s) allocated from:
    #0 0x7f4e3a779ae8 in __interceptor_malloc (/lib64/libasan.so.5+0xefae8)
    #1 0x7f4e398f91d5 in g_malloc (/lib64/libglib-2.0.so.0+0x531d5)
    #2 0x55c9fd9a3999 in qstring_from_substr /build/qemu/src/qobject/qstring.c:45
    #3 0x55c9fd894bd3 in qobject_output_type_str /build/qemu/src/qapi/qobject-output-visitor.c:175
    #4 0x55c9fd894bd3 in qobject_output_type_str /build/qemu/src/qapi/qobject-output-visitor.c:168
    #5 0x55c9fd88b34d in visit_type_str /build/qemu/src/qapi/qapi-visit-core.c:308
    #6 0x55c9fd59aa6b in property_get_str /build/qemu/src/qom/object.c:2064
    #7 0x55c9fd5adb8a in object_property_get_qobject /build/qemu/src/qom/qom-qobject.c:38
    #8 0x55c9fd4a029d in hmp_qom_get /build/qemu/src/qom/qom-hmp-cmds.c:66

Fixes: 89cf4fe3
Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com>
Message-Id: <20200603070338.7922-1-pannengyuan@huawei.com>
Reviewed-by: Li Qiang <liq3ea@gmail.com>
Tested-by: Li Qiang <liq3ea@gmail.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

"info qom-tree" prints children in unstable order.  This is a pain
when diffing output for different versions to find change.  Print it
sorted.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200527084754.7531-3-armbru@redhat.com>
Tested-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

Simplify qom_set by making it use qmp_qom_set and the JSON parser.

(qemu) qom-get /machine smm
"auto"
(qemu) qom-set /machine smm "auto"

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20200520151108.160598-3-dgilbert@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
  With 's'->'S' type change suggested by Paolo and Markus

This started off as Andreas Färber's implementation from
March 2015, but after feedback from Paolo and Markus it morphed into
using the json output which handles structs reasonably.

Use with qom-list to find the members of an object.

(qemu) qom-get /backend/console[0]/device/vga.rom[0] size
65536
(qemu) qom-get /machine smm
"auto"
(qemu) qom-get /machine rtc-time
{
    "tm_year": 120,
    "tm_sec": 51,
    "tm_hour": 9,
    "tm_min": 50,
    "tm_mon": 4,
    "tm_mday": 20
}
(qemu) qom-get /machine frob
Error: Property '.frob' not found

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Message-Id: <20200520151108.160598-2-dgilbert@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

We don't need Error **, as all callers pass local Error object, which
isn't used after the call. Use Error * instead.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20191205174635.18758-5-vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

Move the HMP command handlers related to QOM handlers from
monitor/hmp-cmds.c and qdev-monitor.c to new qom/qom-hmp-cmds.c, where
they are covered by MAINTAINERS section QOM.

Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: "Daniel P. Berrange" <berrange@redhat.com>
Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190619201050.19040-7-armbru@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
[Also move hmp_info_qom_tree(), tweak commit message accordingly]