init_event_facility() creates the SCLP events bus with two SCLP event
devices (sclpquiesce and sclp-cpu-hotplug). It leaves the devices
unrealized. A comment explains they will be realized "via the bus".
The bus's realize method sclp_events_bus_realize() indeed realizes all
unrealized devices on this bus. It carries a TODO comment claiming
this "has to be done in common code". No other bus realize method
realizes its devices.
The common code in question is bus_set_realized(), which has a TODO
comment asking for recursive realization. It's been asking for years.
The only devices sclp_events_bus_realize() will ever realize are the
two init_event_facility() puts there.
Simplify as follows:
* Make the devices members of the event facility instance struct, just
like the bus. object_initialize_child() is simpler than
object_property_add_child() and object_unref().
* Realize them in the event facility realize method.
This is in line with how such things are done elsewhere.
Cc: Cornelia Huck <cohuck@redhat.com>
Cc: Halil Pasic <pasic@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Richard Henderson <rth@twiddle.net>
Cc: David Hildenbrand <david@redhat.com>
Cc: qemu-s390x@nongnu.org
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Acked-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-54-armbru@redhat.com>
Suggested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-53-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-52-armbru@redhat.com>
This is still the same transformation as in the previous commits, but
here the sysbus_init_child_obj() and its matching realize in are in
separate files. Fortunately, there's just one realize left to
convert.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-51-armbru@redhat.com>
These are init/realize pairs produced by the previous commit's
Coccinelle script where the argument test doesn't quite match. They
need even more careful review.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-50-armbru@redhat.com>
This is the same transformation as in the previous commit, except
sysbus_init_child_obj() and realize are too separated for the commit's
Coccinelle script to handle, typically because sysbus_init_child_obj()
is in a device's instance_init() method, and the matching realize is
in its realize() method.
Perhaps a Coccinelle wizard could make it transform that pattern, but
I'm just a bungler, and the best I can do is transforming the two
separate parts separately:
@@
expression errp;
expression child;
symbol true;
@@
- object_property_set_bool(OBJECT(child), true, "realized", errp);
+ sysbus_realize(SYS_BUS_DEVICE(child), errp);
// only correct with a matching sysbus_init_child_obj() transformation!
@@
expression errp;
expression child;
symbol true;
@@
- object_property_set_bool(child, true, "realized", errp);
+ sysbus_realize(SYS_BUS_DEVICE(child), errp);
// only correct with a matching sysbus_init_child_obj() transformation!
@@
expression child;
@@
- qdev_init_nofail(DEVICE(child));
+ sysbus_realize(SYS_BUS_DEVICE(child), &error_fatal);
// only correct with a matching sysbus_init_child_obj() transformation!
@@
expression child;
expression dev;
@@
dev = DEVICE(child);
...
- qdev_init_nofail(dev);
+ sysbus_realize(SYS_BUS_DEVICE(dev), &error_fatal);
// only correct with a matching sysbus_init_child_obj() transformation!
@@
expression child;
identifier dev;
@@
DeviceState *dev = DEVICE(child);
...
- qdev_init_nofail(dev);
+ sysbus_realize(SYS_BUS_DEVICE(dev), &error_fatal);
// only correct with a matching sysbus_init_child_obj() transformation!
@@
expression parent, name, size, type;
expression child;
symbol true;
@@
- sysbus_init_child_obj(parent, name, child, size, type);
+ sysbus_init_child_XXX(parent, name, child, size, type);
@@
expression parent, propname, type;
expression child;
@@
- sysbus_init_child_XXX(parent, propname, child, sizeof(*child), type)
+ object_initialize_child(parent, propname, child, type)
@@
expression parent, propname, type;
expression child;
@@
- sysbus_init_child_XXX(parent, propname, &child, sizeof(child), type)
+ object_initialize_child(parent, propname, &child, type)
This script is *unsound*: we need to manually verify init and realize
conversions are properly paired.
This commit has only the pairs where object_initialize_child()'s
@child and sysbus_realize()'s @dev argument text match exactly within
the same source file.
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>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-49-armbru@redhat.com>
The "null @bus means main system bus" convenience feature is no longer
used. Drop it.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-47-armbru@redhat.com>
Sysbus devices almost always plug into the main system bus.
qdev_create() even has a convenience feature to make that easy: a null
bus argument gets replaced by the main system bus. qdev_realize() and
qdev_realize_and_unref() do the same.
We can do better. Provide convenience wrappers around qdev_realize()
and qdev_realize_and_unref() that don't take a @bus argument. They
always pass the main system bus.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-45-armbru@redhat.com>
The callers of sysbus_init_child_obj() commonly pass either &child,
sizeof(child), or pchild, sizeof(*pchild). Tidy up the few that use
something else instead, mostly to keep future commits simpler.
Coccinelle script:
@@
expression parent, propname, type;
expression child;
type T;
T proxy;
@@
(
sysbus_init_child_obj(parent, propname, &child, sizeof(child), type)
|
sysbus_init_child_obj(parent, propname, child, sizeof(*child), type)
|
- sysbus_init_child_obj(parent, propname, child, sizeof(proxy), type)
+ sysbus_init_child_obj(parent, propname, child, sizeof(*child), type)
)
This script is *unsound*: for each change we need to verify the
@childsize argument stays the same. I did.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-44-armbru@redhat.com>
armsse_init() initializes s->armv7m[i] for all i. It passes the size
of the entire array instead of the array element to
sysbus_init_child_obj(). Harmless, but fix it anyway.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-43-armbru@redhat.com>
The callers of sysbus_init_child_obj() commonly pass either &child,
sizeof(child), or pchild, sizeof(*pchild). Tidy up two that don't,
mostly to keep future commits simpler.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-41-armbru@redhat.com>
OBJECT(child) expands to ((Object *)(child)). sysbus_init_child_obj()
parameter @child is void *. Pass child instead of OBJECT(child).
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-40-armbru@redhat.com>
macio_init_child_obj() has become a trivial wrapper around
object_initialize_child_with_props(). Eliminate it, since the general
convenience wrapper object_initialize_child() is just as convenient
already.
Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-39-armbru@redhat.com>
Convert qdev_set_parent_bus()/realize to qdev_realize(); recent commit
"qdev: New qdev_new(), qdev_realize(), etc." explains why.
Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-38-armbru@redhat.com>
The callers of object_initialize_child() commonly pass either
&child, sizeof(child), or pchild, sizeof(*pchild). Tidy up the few
that don't, mostly to keep the next commit simpler.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-36-armbru@redhat.com>
aux_create_slave() has become a trivial wrapper around qdev_new().
There's just one user. Eliminate.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-35-armbru@redhat.com>
aux_bus_init() encapsulates the creation of an aux-bus and its
aux-to-i2c-bridge device.
Create aux_bus_realize() to similarly encapsulate their realization.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-33-armbru@redhat.com>
Suggested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-32-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-31-armbru@redhat.com>
usb_try_create_simple() is qdev_try_new() and qdev_realize_and_unref()
with more verbose error messages. Of its two users, one ignores
errors, and the other asserts they are impossible.
Make them use qdev_try_new() and qdev_realize_and_unref() directly,
and eliminate usb_try_create_simple
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-30-armbru@redhat.com>
I'm converting from qdev_create()/qdev_init_nofail() to
qdev_new()/qdev_realize_and_unref(); recent commit "qdev: New
qdev_new(), qdev_realize(), etc." explains why.
USB devices use qdev_create() through usb_create().
Provide usb_new() and usb_realize_and_unref() for converting USB
devices.
Cc: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-27-armbru@redhat.com>
Cc: Alistair Francis <alistair@alistair23.me>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-26-armbru@redhat.com>
Same transformation as in the previous commit. Manual, because
convincing Coccinelle to transform this case is not worthwhile.
Cc: Alistair Francis <alistair@alistair23.me>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-25-armbru@redhat.com>
ssi_auto_connect_slaves(parent, cs_line, bus) iterates over @parent's
QOM children @dev of type TYPE_SSI_SLAVE. It puts these on @bus, and
sets cs_line[] to qdev_get_gpio_in_named(dev, SSI_GPIO_CS, 0).
Suspicious: there is no protection against overrunning cs_line[].
Turns out it's safe because ssi_auto_connect_slaves() never finds any
such children. Its called by realize methods of some (but not all)
devices providing an SSI bus, and gets passed the device.
SSI slave devices are always created with ssi_create_slave_no_init(),
optionally via ssi_create_slave(). This adds them to their SSI bus.
It doesn't set their QOM parent.
ssi_create_slave_no_init() is always immediately followed by
qdev_init_nofail(), with no QOM parent assigned, so
device_set_realized() puts the device into the /machine/unattached/
orphanage. None become QOM children of a device providing an SSI bus.
ssi_auto_connect_slaves() was added in commit b4ae3cfa57 "ssi: Add
slave autoconnect helper". I can't see which slaves it was supposed
to connect back then.
Cc: Alistair Francis <alistair@alistair23.me>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-23-armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-22-armbru@redhat.com>
Same transformation as in the previous commit. Manual, because
convincing Coccinelle to transform these cases is not worthwhile.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-21-armbru@redhat.com>
I'm converting from qdev_create()/qdev_init_nofail() to
qdev_new()/qdev_realize_and_unref(); recent commit "qdev: New
qdev_new(), qdev_realize(), etc." explains why.
ISA devices use qdev_create() through isa_create() and
isa_try_create().
Provide isa_new(), isa_try_new(), and isa_realize_and_unref() for
converting ISA devices.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-19-armbru@redhat.com>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-18-armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Same transformation as in the previous commit. Manual, because
convincing Coccinelle to transform these cases is not worthwhile.
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-17-armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-15-armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
I'm converting from qdev_create()/qdev_init_nofail() to
qdev_new()/qdev_realize_and_unref(); recent commit "qdev: New
qdev_new(), qdev_realize(), etc." explains why.
PCI devices use qdev_create() through pci_create() and
pci_create_multifunction().
Provide pci_new(), pci_new_multifunction(), and
pci_realize_and_unref() for converting PCI devices.
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-14-armbru@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Same transformation as in the previous commit. Manual, because
convincing Coccinelle to transform these cases is somewhere between
not worthwhile and infeasible (at least for me).
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-13-armbru@redhat.com>
In addition to the qdev_create() patterns converted so far, we have a
qdev_set_parent_bus() pattern. Mostly when we embed a device in a
parent device rather than allocating it on the heap.
This pattern also puts devices in the dangerous "no QOM parent, but
plugged into bus" state I explained in recent commit "qdev: New
qdev_new(), qdev_realize(), etc."
Apply same solution: convert to qdev_realize(). Coccinelle script:
@@
expression dev, bus, errp;
symbol true;
@@
- qdev_set_parent_bus(DEVICE(dev), bus);
...
- object_property_set_bool(OBJECT(dev), true, "realized", errp);
+ qdev_realize(DEVICE(dev), bus, errp);
@ depends on !(file in "qdev-monitor.c") && !(file in "hw/core/qdev.c")@
expression dev, bus, errp;
symbol true;
@@
- qdev_set_parent_bus(dev, bus);
...
- object_property_set_bool(OBJECT(dev), true, "realized", errp);
+ qdev_realize(dev, bus, errp);
@@
expression dev, bus;
symbol true;
@@
- qdev_set_parent_bus(DEVICE(dev), bus);
...
- qdev_init_nofail(DEVICE(dev));
+ qdev_realize(DEVICE(dev), bus, &error_fatal);
Unconverted uses of qdev_set_parent_bus() remain. They'll be
converted later in this series.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-12-armbru@redhat.com>
[Also convert new hw/virtio/vhost-user-vsock-pci.c]
Same transformation as in the previous commit. Manual, because
convincing Coccinelle to transform these cases is somewhere between
not worthwhile and infeasible (at least for me).
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-11-armbru@redhat.com>
This is the transformation explained in the commit before previous.
Takes care of just one pattern that needs conversion. More to come in
this series.
Coccinelle script:
@ depends on !(file in "hw/arm/highbank.c")@
expression bus, type_name, dev, expr;
@@
- dev = qdev_create(bus, type_name);
+ dev = qdev_new(type_name);
... when != dev = expr
- qdev_init_nofail(dev);
+ qdev_realize_and_unref(dev, bus, &error_fatal);
@@
expression bus, type_name, dev, expr;
identifier DOWN;
@@
- dev = DOWN(qdev_create(bus, type_name));
+ dev = DOWN(qdev_new(type_name));
... when != dev = expr
- qdev_init_nofail(DEVICE(dev));
+ qdev_realize_and_unref(DEVICE(dev), bus, &error_fatal);
@@
expression bus, type_name, expr;
identifier dev;
@@
- DeviceState *dev = qdev_create(bus, type_name);
+ DeviceState *dev = qdev_new(type_name);
... when != dev = expr
- qdev_init_nofail(dev);
+ qdev_realize_and_unref(dev, bus, &error_fatal);
@@
expression bus, type_name, dev, expr, errp;
symbol true;
@@
- dev = qdev_create(bus, type_name);
+ dev = qdev_new(type_name);
... when != dev = expr
- object_property_set_bool(OBJECT(dev), true, "realized", errp);
+ qdev_realize_and_unref(dev, bus, errp);
@@
expression bus, type_name, expr, errp;
identifier dev;
symbol true;
@@
- DeviceState *dev = qdev_create(bus, type_name);
+ DeviceState *dev = qdev_new(type_name);
... when != dev = expr
- object_property_set_bool(OBJECT(dev), true, "realized", errp);
+ qdev_realize_and_unref(dev, bus, errp);
The first rule exempts hw/arm/highbank.c, because it matches along two
control flow paths there, with different @type_name. Covered by the
next commit's manual conversions.
Missing #include "qapi/error.h" added manually.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-10-armbru@redhat.com>
[Conflicts in hw/misc/empty_slot.c and hw/sparc/leon3.c resolved]
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-9-armbru@redhat.com>
I'm going to convert device realization to qdev_realize() with the
help of Coccinelle. Convert bus realization to qbus_realize() first,
to get it out of Coccinelle's way. Readability improves.
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-7-armbru@redhat.com>
Let's start simple and put qdev_new() to use. Coccinelle script:
@ depends on !(file in "hw/core/qdev.c")@
expression type_name;
@@
- DEVICE(object_new(type_name))
+ qdev_new(type_name)
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-6-armbru@redhat.com>
We commonly plug devices into their bus right when we create them,
like this:
dev = qdev_create(bus, type_name);
Note that @dev is a weak reference. The reference from @bus to @dev
is the only strong one.
We realize at some later time, either with
object_property_set_bool(OBJECT(dev), true, "realized", errp);
or its convenience wrapper
qdev_init_nofail(dev);
If @dev still has no QOM parent then, realizing makes the
/machine/unattached/ orphanage its QOM parent.
Note that the device returned by qdev_create() is plugged into a bus,
but doesn't have a QOM parent, yet. Until it acquires one,
unrealizing the bus will hang in bus_unparent():
while ((kid = QTAILQ_FIRST(&bus->children)) != NULL) {
DeviceState *dev = kid->child;
object_unparent(OBJECT(dev));
}
object_unparent() does nothing when its argument has no QOM parent,
and the loop spins forever.
Device state "no QOM parent, but plugged into bus" is dangerous.
Paolo suggested to delay plugging into the bus until realize. We need
to plug into the parent bus before we call the device's realize
method, in case it uses the parent bus. So the dangerous state still
exists, but only within realization, where we can manage it safely.
This commit creates infrastructure to do this:
dev = qdev_new(type_name);
...
qdev_realize_and_unref(dev, bus, errp)
Note that @dev becomes a strong reference here.
qdev_realize_and_unref() drops it. There is also plain
qdev_realize(), which doesn't drop it.
The remainder of this series will convert all users to this new
interface.
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Cc: Alistair Francis <alistair@alistair23.me>
Cc: Gerd Hoffmann <kraxel@redhat.com>
Cc: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
Cc: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Acked-by: Gerd Hoffmann <kraxel@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Message-Id: <20200610053247.1583243-5-armbru@redhat.com>