Commit Graph

123 Commits

Author SHA1 Message Date
Daniel P. Berrangé efba15959c qom: simplify object_find_property / object_class_find_property
When debugging QEMU it is often useful to put a breakpoint on the
error_setg_internal method impl.

Unfortunately the object_property_add / object_class_property_add
methods call object_property_find / object_class_property_find methods
to check if a property exists already before adding the new property.

As a result there are a huge number of calls to error_setg_internal
on startup of most QEMU commands, making it very painful to set a
breakpoint on this method.

Most callers of object_find_property and object_class_find_property,
however, pass in a NULL for the Error parameter. This simplifies the
methods to remove the Error parameter entirely, and then adds some
new wrapper methods that are able to raise an Error when needed.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200914135617.1493072-1-berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-22 16:45:16 -04:00
Eduardo Habkost 30b5707c26 qom: Remove module_obj_name parameter from OBJECT_DECLARE* macros
One of the goals of having less boilerplate on QOM declarations
is to avoid human error.  Requiring an extra argument that is
never used is an opportunity for mistakes.

Remove the unused argument from OBJECT_DECLARE_TYPE and
OBJECT_DECLARE_SIMPLE_TYPE.

Coccinelle patch used to convert all users of the macros:

  @@
  declarer name OBJECT_DECLARE_TYPE;
  identifier InstanceType, ClassType, lowercase, UPPERCASE;
  @@
   OBJECT_DECLARE_TYPE(InstanceType, ClassType,
  -                    lowercase,
                       UPPERCASE);

  @@
  declarer name OBJECT_DECLARE_SIMPLE_TYPE;
  identifier InstanceType, lowercase, UPPERCASE;
  @@
   OBJECT_DECLARE_SIMPLE_TYPE(InstanceType,
  -                    lowercase,
                       UPPERCASE);

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Igor Mammedov <imammedo@redhat.com>
Acked-by: Paul Durrant <paul@xen.org>
Acked-by: Thomas Huth <thuth@redhat.com>
Message-Id: <20200916182519.415636-4-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-18 14:12:32 -04:00
Eduardo Habkost c734cd40a1 qom: Remove ParentClassType argument from OBJECT_DECLARE_SIMPLE_TYPE
The requirement to specify the parent class type makes the macro
harder to use and easy to misuse (silent bugs can be introduced
if the wrong struct type is specified).

Simplify the macro by just not declaring any class struct,
allowing us to remove the class_size field from the TypeInfo
variables for those types.

Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200916182519.415636-3-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-18 14:12:32 -04:00
Richard Henderson 4c880f363e qom: Allow objects to be allocated with increased alignment
It turns out that some hosts have a default malloc alignment less
than that required for vectors.

We assume that, with compiler annotation on CPUArchState, that we
can properly align the vector portion of the guest state.  Fix the
alignment of the allocation by using qemu_memalloc when required.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20200916004638.2444147-3-richard.henderson@linaro.org>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-18 13:59:51 -04:00
Markus Armbruster a21e660777 qom: Correct error values in two contracts
object_property_get_bool()'s contract claims it returns NULL on error.
Pasto; it returns false.

object_property_get_int()'s contract claims it returns "negative".  It
actually returns -1.  All the other object_property_get_FOO()
contracts specify the exact error value, so do the same here.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200917125540.597786-3-armbru@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-18 13:49:48 -04:00
Markus Armbruster d20f616e8f qom: Clean up object_property_get_enum()'s error value
object_property_get_enum() is the only object_property_FOO() that is
documented to return an undefined value on error.  It does no such
thing, actually: it returns 0 on some errors, and -1 on others.

Needlessly complicated.  Always return -1 on error, and adjust the
contract.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200917125540.597786-2-armbru@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-18 13:49:48 -04:00
Eduardo Habkost 04dcf4b5db qom: Correct object_class_dynamic_cast_assert() documentation
object_class_dynamic_cast_assert() is not used by
INTERFACE_CHECK, remove misleading mention of that function in
the documentation.

Message-Id: <20200916193101.511600-2-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-18 13:49:48 -04:00
Eduardo Habkost db1015e92e Move QOM typedefs and add missing includes
Some typedefs and macros are defined after the type check macros.
This makes it difficult to automatically replace their
definitions with OBJECT_DECLARE_TYPE.

Patch generated using:

 $ ./scripts/codeconverter/converter.py -i \
   --pattern=QOMStructTypedefSplit $(git grep -l '' -- '*.[ch]')

which will split "typdef struct { ... } TypedefName"
declarations.

Followed by:

 $ ./scripts/codeconverter/converter.py -i --pattern=MoveSymbols \
    $(git grep -l '' -- '*.[ch]')

which will:
- move the typedefs and #defines above the type check macros
- add missing #include "qom/object.h" lines if necessary

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20200831210740.126168-9-ehabkost@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Message-Id: <20200831210740.126168-10-ehabkost@redhat.com>
Message-Id: <20200831210740.126168-11-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-09 09:26:43 -04:00
Eduardo Habkost ad09bed1cf qom: Make type checker functions accept const pointers
The existing type check macros all unconditionally drop const
qualifiers from their arguments.  Keep this behavior in the
macros generated by DECLARE_*CHECKER* by now.

Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20200831210740.126168-6-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-08 17:29:19 -04:00
Eduardo Habkost 7808a28f22 qom: DECLARE_*_CHECKERS macros
Sometimes the typedefs are buried inside another header, but
we want to benefit from the automatic definition of type cast
functions.  Introduce macros that will let type checkers be
defined when typedefs are already available.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20200831210740.126168-5-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-08 17:29:18 -04:00
Eduardo Habkost 4a5f0545d2 qom: Allow class type name to be specified in OBJECT_DECLARE*
Many QOM types don't follow the Type/TypeClass pattern
on the instance/struct names.  Let the class struct name
be specified in the OBJECT_DECLARE* macros.

Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20200831210740.126168-4-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-08 17:29:18 -04:00
Daniel P. Berrangé f84203a8c2 qom: provide convenient macros for declaring and defining types
When creating new QOM types, there is a lot of boilerplate code that
must be repeated using a standard pattern. This is tedious to write
and liable to suffer from subtle inconsistencies. Thus it would
benefit from some simple automation.

QOM was loosely inspired by GLib's GObject, and indeed GObject suffers
from the same burden of boilerplate code, but has long provided a set of
macros to eliminate this burden in the source implementation. More
recently it has also provided a set of macros to eliminate this burden
in the header declaration.

In GLib there are the G_DECLARE_* and G_DEFINE_* family of macros
for the header declaration and source implementation respectively:

  https://developer.gnome.org/gobject/stable/chapter-gobject.html
  https://developer.gnome.org/gobject/stable/howto-gobject.html

This patch takes inspiration from GObject to provide the equivalent
functionality for QOM.

In the header file, instead of:

    typedef struct MyDevice MyDevice;
    typedef struct MyDeviceClass MyDeviceClass;

    G_DEFINE_AUTOPTR_CLEANUP_FUNC(MyDeviceClass, object_unref)

    #define MY_DEVICE_GET_CLASS(void *obj) \
            OBJECT_GET_CLASS(MyDeviceClass, obj, TYPE_MY_DEVICE)
    #define MY_DEVICE_CLASS(void *klass) \
            OBJECT_CLASS_CHECK(MyDeviceClass, klass, TYPE_MY_DEVICE)
    #define MY_DEVICE(void *obj)
            OBJECT_CHECK(MyDevice, obj, TYPE_MY_DEVICE)

    struct MyDeviceClass {
        DeviceClass parent_class;
    };

We now have

    OBJECT_DECLARE_SIMPLE_TYPE(MyDevice, my_device, MY_DEVICE, DEVICE)

In cases where the class needs some virtual methods, it can be left
to be implemented manually using

    OBJECT_DECLARE_TYPE(MyDevice, my_device, MY_DEVICE)

Note that these macros are including support for g_autoptr() for the
object types, which is something previously only supported for variables
declared as the base Object * type.

Meanwhile in the source file, instead of:

    static void my_device_finalize(Object *obj);
    static void my_device_class_init(ObjectClass *oc, void *data);
    static void my_device_init(Object *obj);

    static const TypeInfo my_device_info = {
        .parent = TYPE_DEVICE,
        .name = TYPE_MY_DEVICE,
        .instance_size = sizeof(MyDevice),
        .instance_init = my_device_init,
        .instance_finalize = my_device_finalize,
        .class_size = sizeof(MyDeviceClass),
        .class_init = my_device_class_init,
    };

    static void
    my_device_register_types(void)
    {
        type_register_static(&my_device_info);
    }
    type_init(my_device_register_types);

We now have

    OBJECT_DEFINE_TYPE(MyDevice, my_device, MY_DEVICE, DEVICE)

Or, if a class needs to implement interfaces:

    OBJECT_DEFINE_TYPE_WITH_INTERFACES(MyDevice, my_device, MY_DEVICE, DEVICE,
                                       { TYPE_USER_CREATABLE }, { NULL })

Or, if a class needs to be abstract

    OBJECT_DEFINE_ABSTRACT_TYPE(MyDevice, my_device, MY_DEVICE, DEVICE)

IOW, in both cases the maintainer now only has to think about the
interesting part of the code which implements useful functionality
and avoids much of the boilerplate.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200723181410.3145233-3-berrange@redhat.com>
[ehabkost: Fix G_DEFINE_AUTOPTR_CLEANUP_FUNC usage]
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20200831210740.126168-3-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-08 17:29:18 -04:00
Daniel P. Berrangé c5a61e5a3c qom: make object_ref/unref use a void * instead of Object *.
The object_ref/unref methods are intended for use with any subclass of
the base Object. Using "Object *" in the signature is not adding any
meaningful level of type safety, since callers simply use "OBJECT(ptr)"
and this expands to an unchecked cast "(Object *)".

By using "void *" we enable the object_unref() method to be used to
provide support for g_autoptr() with any subclass.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20200723181410.3145233-2-berrange@redhat.com>
Message-Id: <20200831210740.126168-2-ehabkost@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-08 17:29:18 -04:00
Markus Armbruster 5bd929d2ff qom: Document object_get_canonical_path() returns malloced string
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200714160202.3121879-5-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-07-21 16:23:43 +02:00
Markus Armbruster 7a309cc95b qom: Change object_get_canonical_path_component() not to malloc
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>
2020-07-21 16:23:43 +02:00
Eric Auger db57fef1e2 qom: Introduce object_property_try_add_child()
object_property_add() does not allow object_property_try_add()
to gracefully fail as &error_abort is passed as an error handle.

However such failure can easily be triggered from the QMP shell when,
for instance, one attempts to create an object with an id that already
exists. This is achieved from the following call path:

qmp_object_add -> user_creatable_add_dict -> user_creatable_add_type ->
object_property_add_child -> object_property_add

For instance, from the qmp-shell, call twice:
object-add qom-type=memory-backend-ram id=mem1 props.size=1073741824
and QEMU aborts.

This behavior is undesired as a user/management application mistake
in reusing a property ID shouldn't result in loss of the VM and live
data within.

This patch introduces a new function, object_property_try_add_child()
which takes an error handle and turn object_property_try_add() into
a non-static one.

Now the call path becomes:

user_creatable_add_type -> object_property_try_add_child ->
object_property_try_add

and the error is returned gracefully to the QMP client.

(QEMU) object-add qom-type=memory-backend-ram id=mem2  props.size=4294967296
{"return": {}}
(QEMU) object-add qom-type=memory-backend-ram id=mem2  props.size=4294967296
{"error": {"class": "GenericError", "desc": "attempt to add duplicate property
'mem2' to object (type 'container')"}}

Signed-off-by: Eric Auger <eric.auger@redhat.com>
Fixes: d2623129a7 ("qom: Drop parameter @errp of object_property_add() & friends")
Reviewed-by: Markus Armbruster <armbru@redhat.com>

Reviewed-by: Greg Kurz <groug@kaod.org>
Tested-by: Greg Kurz <groug@kaod.org>
Message-Id: <20200629193424.30280-2-eric.auger@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-07-10 18:02:16 -04:00
Markus Armbruster b783f54d60 qom: Make functions taking Error ** return bool, not 0/-1
Just for consistency.  Also fix the example in object_set_props()'s
documentation.

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: <20200707160613.848843-31-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster 6fd5bef10b qom: Make functions taking Error ** return bool, not void
See recent commit "error: Document Error API usage rules" for
rationale.

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: <20200707160613.848843-28-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Markus Armbruster 5325cc34a2 qom: Put name parameter before value / visitor parameter
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 2336172d9b "audio: set default
value for pcspk.iobase property" resolved]
2020-07-10 15:18:08 +02:00
Markus Armbruster fdb0df8798 qom: Use error_reportf_err() instead of g_printerr() in examples
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: <20200707160613.848843-22-armbru@redhat.com>
2020-07-10 15:18:08 +02:00
Gerd Hoffmann 0f8198f1b2 object: qom module support
Little helper function to load modules on demand.  In most cases adding
module loading support for devices and other objects is just
s/object_class_by_name/module_object_class_by_name/ in the right spot.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-id: 20200624131045.14512-3-kraxel@redhat.com
2020-07-07 14:54:29 +02:00
Markus Armbruster 9fc7fc4d39 qom: Less verbose object_initialize_child()
All users of object_initialize_child() pass the obvious child size
argument.  Almost all pass &error_abort and no properties.  Tiresome.

Rename object_initialize_child() to
object_initialize_child_with_props() to free the name.  New
convenience wrapper object_initialize_child() automates the size
argument, and passes &error_abort and no properties.

Rename object_initialize_childv() to
object_initialize_child_with_propsv() for consistency.

Convert callers with this Coccinelle script:

    @@
    expression parent, propname, type;
    expression child, size;
    symbol error_abort;
    @@
    -    object_initialize_child(parent, propname, OBJECT(child), size, type, &error_abort, NULL)
    +    object_initialize_child(parent, propname, child, size, type, &error_abort, NULL)

    @@
    expression parent, propname, type;
    expression child;
    symbol error_abort;
    @@
    -    object_initialize_child(parent, propname, child, sizeof(*child), type, &error_abort, NULL)
    +    object_initialize_child(parent, propname, child, type)

    @@
    expression parent, propname, type;
    expression child;
    symbol error_abort;
    @@
    -    object_initialize_child(parent, propname, &child, sizeof(child), type, &error_abort, NULL)
    +    object_initialize_child(parent, propname, &child, type)

    @@
    expression parent, propname, type;
    expression child, size, err;
    expression list props;
    @@
    -    object_initialize_child(parent, propname, child, size, type, err, props)
    +    object_initialize_child_with_props(parent, propname, child, size, type, err, props)

Note that Coccinelle chokes on ARMSSE typedef vs. macro in
hw/arm/armsse.c.  Worked around by temporarily renaming the macro for
the spatch run.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
[Rebased: machine opentitan is new (commit fe0fe4735e)]
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-37-armbru@redhat.com>
2020-06-15 22:05:28 +02:00
Markus Armbruster e8512dfa4d qom: Constify object_get_canonical_path{,_component}()'s parameter
Suggested-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200527084754.7531-2-armbru@redhat.com>
Reviewed-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-06-15 21:34:25 +02:00
Philippe Mathieu-Daudé ca27b5eb7c qom/object: Move Object typedef to 'qemu/typedefs.h'
We use the Object type all over the place.
Forward declare it in "qemu/typedefs.h".

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Message-Id: <20200504115656.6045-2-f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-06-10 12:09:36 -04:00
Markus Armbruster df4fe0b291 qom: Drop @errp parameter of object_property_del()
Same story as for object_property_add(): the only way
object_property_del() can fail is when the property with this name
does not exist.  Since our property names are all hardcoded, failure
is a programming error, and the appropriate way to handle it is
passing &error_abort.  Most callers do that, the commit before
previous fixed one that didn't (and got the error handling wrong), and
the two remaining exceptions ignore errors.

Drop the @errp parameter.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-19-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
2020-05-15 07:08:14 +02:00
Markus Armbruster d2623129a7 qom: Drop parameter @errp of object_property_add() & friends
The only way object_property_add() can fail is when a property with
the same name already exists.  Since our property names are all
hardcoded, failure is a programming error, and the appropriate way to
handle it is passing &error_abort.

Same for its variants, except for object_property_add_child(), which
additionally fails when the child already has a parent.  Parentage is
also under program control, so this is a programming error, too.

We have a bit over 500 callers.  Almost half of them pass
&error_abort, slightly fewer ignore errors, one test case handles
errors, and the remaining few callers pass them to their own callers.

The previous few commits demonstrated once again that ignoring
programming errors is a bad idea.

Of the few ones that pass on errors, several violate the Error API.
The Error ** argument must be NULL, &error_abort, &error_fatal, or a
pointer to a variable containing NULL.  Passing an argument of the
latter kind twice without clearing it in between is wrong: if the
first call sets an error, it no longer points to NULL for the second
call.  ich9_pm_add_properties(), sparc32_ledma_realize(),
sparc32_dma_realize(), xilinx_axidma_realize(), xilinx_enet_realize()
are wrong that way.

When the one appropriate choice of argument is &error_abort, letting
users pick the argument is a bad idea.

Drop parameter @errp and assert the preconditions instead.

There's one exception to "duplicate property name is a programming
error": the way object_property_add() implements the magic (and
undocumented) "automatic arrayification".  Don't drop @errp there.
Instead, rename object_property_add() to object_property_try_add(),
and add the obvious wrapper object_property_add().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-15-armbru@redhat.com>
[Two semantic rebase conflicts resolved]
2020-05-15 07:07:58 +02:00
Markus Armbruster 7eecec7d12 qom: Drop object_property_set_description() parameter @errp
object_property_set_description() and
object_class_property_set_description() fail only when property @name
is not found.

There are 85 calls of object_property_set_description() and
object_class_property_set_description().  None of them can fail:

* 84 immediately follow the creation of the property.

* The one in spapr_rng_instance_init() refers to a property created in
  spapr_rng_class_init(), from spapr_rng_properties[].

Every one of them still gets to decide what to pass for @errp.

51 calls pass &error_abort, 32 calls pass NULL, one receives the error
and propagates it to &error_abort, and one propagates it to
&error_fatal.  I'm actually surprised none of them violates the Error
API.

What are we gaining by letting callers handle the "property not found"
error?  Use when the property is not known to exist is simpler: you
don't have to guard the call with a check.  We haven't found such a
use in 5+ years.  Until we do, let's make life a bit simpler and drop
the @errp parameter.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-8-armbru@redhat.com>
[One semantic rebase conflict resolved]
2020-05-15 07:06:49 +02:00
Markus Armbruster 7025188772 qom: Make all the object_property_add_FOO() return the property
Some object_property_add_FOO() return the newly added property, some
don't.  Clean that up.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-7-armbru@redhat.com>
2020-05-15 06:26:02 +02:00
Markus Armbruster 44a17fe05a qom: Drop convenience method object_property_get_uint16List()
qom/object.c provides object_property_get_TYPE() and
object_property_set_TYPE() for a number of common types.  These are
all convenience wrappers around object_property_get_qobject() and
object_property_set_qobject().

Except for object_property_get_uint16List(), which is unusual in two ways:

* It bypasses object_property_get_qobject().  Fixable; the previous
  commit did it for object_property_get_enum())

* It stores the value through a parameter.  Its contract claims it
  returns the value, like the other functions do.  Also fixable.

Fixing is not worthwhile, though: object_property_get_uint16List() has
seen exactly one user in six years.

Convert the lone user to do its job with the generic
object_property_get_qobject(), and drop object_property_get_uint16List().

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20200505152926.18877-6-armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
[Commit message typo fixed]
2020-05-15 06:26:02 +02:00
Markus Armbruster ddfb0baaf2 qom: Clean up inconsistent use of gchar * vs. char *
Uses of gchar * in qom/object.h:

* ObjectProperty member @name

  Functions that take a property name argument all use char *.  Change
  the member to match.

* ObjectProperty member @type

  Functions that take a property type argument or return it all use
  char *.  Change the member to match.

* ObjectProperty member @description

  Functions that take a property description argument all use char *.
  Change the member to match.

* object_resolve_path_component() parameter @part

  Path components are property names.  Most callers pass char *
  arguments.  Change the parameter to match.  Adjust the few callers
  that pass gchar * to pass char *.

* Return value of object_get_canonical_path_component(),
  object_get_canonical_path()

  Most callers convert their return values right back to char *.
  Change the return value to match.  Adjust the few callers where that
  would add a conversion to gchar * to use char * instead.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200505152926.18877-3-armbru@redhat.com>
2020-05-15 06:26:02 +02:00
Felipe Franciosi 836e1b3813 qom/object: enable setter for uint types
Traditionally, the uint-specific property helpers only offer getters.
When adding object (or class) uint types, one must therefore use the
generic property helper if a setter is needed (and probably duplicate
some code writing their own getters/setters).

This enhances the uint-specific property helper APIs by adding a
bitwise-or'd 'flags' field and modifying all clients of that API to set
this paramater to OBJ_PROP_FLAG_READ. This maintains the current
behaviour whilst allowing others to also set OBJ_PROP_FLAG_WRITE (or use
the more convenient OBJ_PROP_FLAG_READWRITE) in the future (which will
automatically install a setter). Other flags may be added later.

Signed-off-by: Felipe Franciosi <felipe@nutanix.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-03-16 23:02:23 +01:00
Marc-André Lureau 4df8161673 qom: introduce object_property_help()
Let's factor out the code to format a help string for a property. We
are going to reuse it in qdev next, which will bring some consistency.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-25-marcandre.lureau@redhat.com>
[Adjust for removal of object_property_get_default, move default
 after description. - Paolo]
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-24 20:59:16 +01:00
Marc-André Lureau b77ade9bb3 object: return self in object_ref()
This allow for simpler assignment with ref: foo = object_ref(bar)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200110153039.1379601-19-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-24 20:59:14 +01:00
Marc-André Lureau 840ecdfbf9 object: add object_class_property_add_link()
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-17-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-24 20:59:14 +01:00
Marc-André Lureau 9941d37b4d object: add direct link flag
Allow the link property to hold the pointer to the target, instead of
indirectly through another variable.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-15-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-24 20:59:14 +01:00
Marc-André Lureau 36854207f0 object: rename link "child" to "target"
A child property is a different kind of property. Let's use "target"
for the link target.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-14-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-24 20:59:14 +01:00
Marc-André Lureau 0e76ed0a5d object: add object_property_set_default
Add a default value to ObjectProperty and an implementation of
ObjectPropertyInit that uses it.  This will make it easier to show the
default in help messages.

Also provide convenience functions object_property_set_default_{bool,
str, int, uint}().

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-11-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-24 20:59:13 +01:00
Marc-André Lureau a3a162113e object: make object_class_property_add* return property
This will help calling other ObjectProperty associated functions
easily after.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-9-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-24 20:59:13 +01:00
Marc-André Lureau 2a1be4b348 object: add class property initializer
This callback is used to set default value in following patch "object:
add object_property_set_defaut_{bool,str,int,uint}()".

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-Id: <20200110153039.1379601-7-marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2020-01-24 20:59:12 +01:00
Marc-André Lureau f60a1cdca5 object: add g_autoptr support
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
2020-01-02 13:54:57 +04:00
Peter Maydell 4800819827 * More uses of RCU_READ_LOCK_GUARD (Dave, myself)
* QOM doc improvments (Greg)
 * Cleanups from the Meson conversion (Marc-André)
 * Support for multiple -accel options (myself)
 * Many x86 machine cleanup (Philippe, myself)
 * tests/migration-test cleanup (Juan)
 * PC machine removal and next round of deprecation (Thomas)
 * kernel-doc integration (Peter, myself)
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Merge remote-tracking branch 'remotes/bonzini/tags/for-upstream' into staging

* More uses of RCU_READ_LOCK_GUARD (Dave, myself)
* QOM doc improvments (Greg)
* Cleanups from the Meson conversion (Marc-André)
* Support for multiple -accel options (myself)
* Many x86 machine cleanup (Philippe, myself)
* tests/migration-test cleanup (Juan)
* PC machine removal and next round of deprecation (Thomas)
* kernel-doc integration (Peter, myself)

# gpg: Signature made Wed 18 Dec 2019 01:35:02 GMT
# gpg:                using RSA key BFFBD25F78C7AE83
# gpg: Good signature from "Paolo Bonzini <bonzini@gnu.org>" [full]
# gpg:                 aka "Paolo Bonzini <pbonzini@redhat.com>" [full]
# Primary key fingerprint: 46F5 9FBD 57D6 12E7 BFD4  E2F7 7E15 100C CD36 69B1
#      Subkey fingerprint: F133 3857 4B66 2389 866C  7682 BFFB D25F 78C7 AE83

* remotes/bonzini/tags/for-upstream: (87 commits)
  vga: cleanup mapping of VRAM for non-PCI VGA
  hw/display: Remove "rombar" hack from vga-pci and vmware_vga
  hw/pci: Remove the "command_serr_enable" property
  hw/audio: Remove the "use_broken_id" hack from the AC97 device
  hw/i386: Remove the deprecated machines 0.12 up to 0.15
  hw/pci-host: Add Kconfig entry to select the IGD Passthrough Host Bridge
  hw/pci-host/i440fx: Extract the IGD passthrough host bridge device
  hw/pci-host/i440fx: Use definitions instead of magic values
  hw/pci-host/i440fx: Use size_t to iterate over ARRAY_SIZE()
  hw/pci-host/i440fx: Extract PCII440FXState to "hw/pci-host/i440fx.h"
  hw/pci-host/i440fx: Correct the header description
  Fix some comment spelling errors.
  target/i386: remove unused pci-assign codes
  WHPX: refactor load library
  migration: check length directly to make sure the range is aligned
  memory: include MemoryListener documentation and some missing function parameters
  docs: add memory API reference
  memory.h: Silence kernel-doc complaints
  docs: Create bitops.rst as example of kernel-docs
  bitops.h: Silence kernel-doc complaints
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
2019-12-20 11:20:25 +00:00
Vladimir Sementsov-Ogievskiy 1dc6ba2425 include/qom/object.h: rename Error ** parameter to more common errp
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20191205174635.18758-19-vsementsov@virtuozzo.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
2019-12-18 08:43:19 +01:00
Greg Kurz 55deffdb5c object: Improve documentation of interfaces
QOM interfaces allow a limited form of multiple inheritance, at the
condition of being stateless. That is, they cannot be instantiated
and a pointer to an interface shouldn't be dereferenceable in any way.
This is achieved by making the QOM instance type an incomplete type,
which is, as mentioned by Markus Armbruster, the closest you can get
to abstract class in C.

Incomplete types are widely used to hide implementation details, but
people usually expect to find at least one place where the type is
fully defined. The fact that it doesn't happen with QOM interfaces is
quite disturbing, especially since it isn't documented anywhere as
recently discussed in this thread:

https://lists.gnu.org/archive/html/qemu-devel/2019-12/msg01579.html

Amend the documentation in the object.h header file to provide more
details about why and how to implement QOM interfaces using incomplete
types.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-12-17 19:32:46 +01:00
Paolo Bonzini 3c75e12ea6 qom: add object_new_with_class
Similar to CPU and machine classes, "-accel" class names are mangled,
so we have to first get a class via accel_find and then instantiate it.
Provide a new function to instantiate a class without going through
object_class_get_name, and use it for CPUs and machines already.

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-12-17 19:32:26 +01:00
Paolo Bonzini 1fff3c206f qom: introduce object_register_sugar_prop
Similar to the existing "-rtc driftfix" option, we will convert some
legacy "-machine" command line options to global properties on accelerators.
Because accelerators are not devices, we cannot use qdev_prop_register_global.
Instead, provide a slot in the generic object_compat_props arrays for
command line syntactic sugar.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-12-17 19:32:26 +01:00
Markus Armbruster dc5e9ac716 Include qemu/queue.h slightly less
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-20-armbru@redhat.com>
2019-08-16 13:31:52 +02:00
Markus Armbruster 0b8fa32f55 Include qemu/module.h where needed, drop it from qemu-common.h
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20190523143508.25387-4-armbru@redhat.com>
[Rebased with conflicts resolved automatically, except for
hw/usb/dev-hub.c hw/misc/exynos4210_rng.c hw/misc/bcm2835_rng.c
hw/misc/aspeed_scu.c hw/display/virtio-vga.c hw/arm/stm32f205_soc.c;
ui/cocoa.m fixed up]
2019-06-12 13:18:33 +02:00
Markus Armbruster 617902af2c qom: Move compat_props machinery from qdev to QOM
See the previous commit for rationale.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190308131445.17502-3-armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
2019-03-11 22:53:44 +01:00
Marc-André Lureau ea9ce8934c hw: apply accel compat properties without touching globals
Instead of registering compat properties as globals, let's keep them
in their own array, to avoid mixing with user globals.

Introduce object_apply_global_props() function, to apply compatibility
properties from a GPtrArray.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Acked-by: Eduardo Habkost <ehabkost@redhat.com>
2019-01-07 16:18:41 +04:00
Marc-André Lureau 37fdb2c56c qom: remove unimplemented class_finalize
Instead of trying to implement something that isn't well specified,
remove it. (it would be tricky to implement, since a class struct is
memcpy on children types...)

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Igor Mammedov <imammedo@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20181204142023.15982-7-marcandre.lureau@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2018-12-11 15:45:23 -02:00