QEMU object model is scarse in documentation. Some calls are
recursive, and it might be hard to figure out even trivial issues.
We can avoid developers to waste time in a debugging session by
displaying a simple error message.
This commit is also similar to e02bdf1cec ("Display more helpful
message when an object type is missing").
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Message-Id: <20200121110349.25842-7-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
When adding new devices implementing QOM interfaces, we might
forgot to add the Kconfig dependency that pulls the required
objects in when building.
Since QOM dependencies are resolved at runtime, we don't get any
link-time failures, and QEMU aborts while starting:
$ qemu ...
Segmentation fault (core dumped)
(gdb) bt
#0 0x00007ff6e96b1e35 in raise () from /lib64/libc.so.6
#1 0x00007ff6e969c895 in abort () from /lib64/libc.so.6
#2 0x00005572bc5051cf in type_initialize (ti=0x5572be6f1200) at qom/object.c:323
#3 0x00005572bc505074 in type_initialize (ti=0x5572be6f1800) at qom/object.c:301
#4 0x00005572bc505074 in type_initialize (ti=0x5572be6e48e0) at qom/object.c:301
#5 0x00005572bc506939 in object_class_by_name (typename=0x5572bc56109a) at qom/object.c:959
#6 0x00005572bc503dd5 in cpu_class_by_name (typename=0x5572bc56109a, cpu_model=0x5572be6d9930) at hw/core/cpu.c:286
Since the caller has access to the qdev parent/interface names,
we can simply display them to avoid starting a debugger:
$ qemu ...
qemu: missing interface 'fancy-if' for object 'fancy-dev'
Aborted (core dumped)
This commit is similar to e02bdf1cec ("Display more helpful message
when an object type is missing").
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20200118162348.17823-1-philmd@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
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>
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>
The error message in object_class_property_add() was copied from
object_property_add() in commit 16bf7f522a. Clarify that it is
about a class, not an object.
While here, have the format string in both functions to fit in a
single line for better grep-ability, despite the checkpatch warning.
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Laurent Vivier <laurent@vivier.eu>
Message-Id: <157287383591.234942.311840593519058490.stgit@bahia.tlslab.ibm.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
docs/devel/tracing.txt explains "since many source files include
trace.h, [the generated trace.h use] a minimum of types and other
header files included to keep the namespace clean and compile times
and dependencies down."
Commit 4815185902 "trace: Add per-vCPU tracing states for events with
the 'vcpu' property" made them all include qom/cpu.h via
control-internal.h. qom/cpu.h in turn includes about thirty headers.
Ouch.
Per-vCPU tracing is currently not supported in sub-directories'
trace-events. In other words, qom/cpu.h can only be used in
trace-root.h, not in any trace.h.
Split trace/control-vcpu.h off trace/control.h and
trace/control-internal.h. Have the generated trace.h include
trace/control.h (which no longer includes qom/cpu.h), and trace-root.h
include trace/control-vcpu.h (which includes it).
The resulting improvement is a bit disappointing: in my "build
everything" tree, some 1100 out of 6600 objects (not counting tests
and objects that don't depend on qemu/osdep.h) depend on a trace.h,
and about 600 of them no longer depend on qom/cpu.h. But more than
1300 others depend on trace-root.h. More work is clearly needed.
Left for another day.
Cc: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190812052359.30071-8-armbru@redhat.com>
When writing a new board, adding device which uses other devices
(container) or simply refactoring, one can discover the hard way
his machine misses some devices. In the case of containers, the
error is not obvious:
$ qemu-system-microblaze -M xlnx-zynqmp-pmu
**
ERROR:/source/qemu/qom/object.c:454:object_initialize_with_type: assertion failed: (type != NULL)
Aborted (core dumped)
And we have to look at the coredump to figure the error:
(gdb) bt
#1 0x00007f84773cf895 in abort () at /lib64/libc.so.6
#2 0x00007f847961fb53 in () at /lib64/libglib-2.0.so.0
#3 0x00007f847967a4de in g_assertion_message_expr () at /lib64/libglib-2.0.so.0
#4 0x000055c4bcac6c11 in object_initialize_with_type (data=data@entry=0x55c4bdf239e0, size=size@entry=2464, type=<optimized out>) at /source/qemu/qom/object.c:454
#5 0x000055c4bcac6e6d in object_initialize (data=data@entry=0x55c4bdf239e0, size=size@entry=2464, typename=typename@entry=0x55c4bcc7c643 "xlnx.zynqmp_ipi") at /source/qemu/qom/object.c:474
#6 0x000055c4bc9ea474 in xlnx_zynqmp_pmu_init (machine=0x55c4bdd46000) at /source/qemu/hw/microblaze/xlnx-zynqmp-pmu.c:176
#7 0x000055c4bca3b6cb in machine_run_board_init (machine=0x55c4bdd46000) at /source/qemu/hw/core/machine.c:1030
#8 0x000055c4bc95f6d2 in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at /source/qemu/vl.c:4479
Since the caller knows the type name requested, we can simply display it
to ease development.
With this patch applied we get:
$ qemu-system-microblaze -M xlnx-zynqmp-pmu
qemu-system-microblaze: missing object type 'xlnx.zynqmp_ipi'
Aborted (core dumped)
Since the assert(type) check in object_initialize_with_type() is
now impossible, remove it.
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20190427135642.16464-1-philmd@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
This reverts commit d7741743f4.
Relying on setting properties on parents types which may not
be relevant to certain sub-classes had unexpected side-effects
causing bugs in device config defaults. It is preferrable to
be explicit about which devices get which properties, even if
this needs repetition.
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20190215103239.28640-3-berrange@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
When an object is in turn owned by another user object, it is not
desirable to expose this in the QOM object hierarchy. It is just an
internal implementation detail, we should be free to change without
exposure to apps managing QEMU.
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Making some global properties optional will let us simplify
compat code when a given property works on most (but not all)
subclasses of a given type.
Device types will be able to opt out from optional compat
properties by simply not registering those properties.
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
When handling errp==NULL at object_apply_global_props(), we are
leaving the old error value in `err` after printing a warning.
This makes QEMU crash if two global properties generate warnings:
$ echo device_add rtl8139 | qemu-system-x86_64 -monitor stdio -global rtl8139.xxx=yyy -global rtl8139.xxx=zzz
warning: can't apply global rtl8139.xxx=yyy: Property '.xxx' not found
qemu-system-x86_64: util/error.c:57: error_setv: Assertion `*errp == NULL' failed.
Aborted (core dumped)
Fix that by making `err` go out of scope immediately after the
warn_report_err() call.
Fixes: 50545b2cc0 "qdev-props: call object_apply_global_props()"
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
Message-Id: <20190110020259.8492-2-ehabkost@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
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>
object_class_property_iter_init() starts from the given class, so the
next class should continue with the parent class.
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
A lot of code is using the object_initialize() function followed by a call
to object_property_add_child() to add the newly initialized object as a child
of the current object. Both functions increase the reference counter of the
new object, but many spots that call these two functions then forget to drop
one of the superfluous references. So the newly created object is often not
cleaned up correctly when the parent is destroyed. In the worst case, this
can cause crashes, e.g. because device objects are not correctly removed from
their parent_bus.
Since this is a common pattern between many code spots, let's introduce a
new function that takes care of calling all three required initialization
functions, first object_initialize(), then object_property_add_child() and
finally object_unref(). And since the function does a similar job like
object_new_with_props(), also allow to set additional properties via
varargs, and use user_creatable_complete() to make sure that the functions
can be used similarly.
And while we're at object.h, also fix some copy-n-paste errors in the
comments there ("to store the area" --> "to store the error").
Signed-off-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Message-id: 1531745974-17187-2-git-send-email-thuth@redhat.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
A link property can be set during creation, with
object_property_add_link() and later with object_property_set_link().
add_link() doesn't add a reference to the target object, while
set_link() does.
Furthemore, OBJ_PROP_LINK_UNREF_ON_RELEASE flags, set during add_link,
says whether a reference must be released when the property is destroyed.
This can lead to leaks if the property was later set_link(), as the
added reference is never released.
Instead, rename OBJ_PROP_LINK_UNREF_ON_RELEASE to OBJ_PROP_LINK_STRONG
and use that has an indication on how the link handle reference
management in set_link().
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-id: 20180531195119.22021-3-marcandre.lureau@redhat.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Mostly a rewrite, in order to keep the loop simple.
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
