Re: [Qemu-devel] [PATCH] qdev: Fix qdev_try_create() for bus-less devices

[Andreas Färber]

Am 05.02.2014 17:38, schrieb Paolo Bonzini:
> Il 05/02/2014 15:09, Andreas Färber ha scritto:
>> diff --git a/hw/core/qdev.c b/hw/core/qdev.c
>> index 82a9123..14c8765 100644
>> --- a/hw/core/qdev.c
>> +++ b/hw/core/qdev.c
>> @@ -131,21 +131,27 @@ DeviceState *qdev_create(BusState *bus, const
>> char *name)
>>  DeviceState *qdev_try_create(BusState *bus, const char *type)
>>  {
>>      DeviceState *dev;
>> +    ObjectClass *oc;
>> +    DeviceClass *dc;
>>
>> -    if (object_class_by_name(type) == NULL) {
>> +    oc = object_class_by_name(type);
>> +    if (oc == NULL) {
>>          return NULL;
>>      }
>> +    dc = DEVICE_CLASS(oc);
>>      dev = DEVICE(object_new(type));
>>      if (!dev) {
>>          return NULL;
>>      }
>>
>> -    if (!bus) {
>> +    if (!bus && dc->bus_type && strcmp(dc->bus_type, "System") == 0) {
> 
> Should you check instead if dev is-a TYPE_SYSBUS_DEVICE?

Hmm, that would catch TYPE_SYS_BUS_DEVICE-derived types as well, which
might in theory override bus_type.

The ugly thing here is the cyclic dependency betwen qdev and sysbus,
therefore no TYPE_SYSTEM_BUS.

> Does this also leave the nand device out of info qtree, or is it still
> dumped?

As I pointed out several times already, devices that are not on a bus
are generally *not* printed by info qtree. It depends on the old qbus
concept. Therefore info qtree is not of much use anymore and should be
dropped in favor of the qom-list and qom-get operations, which get us
all devices and all properties. I had once attached a qom-tree for that
and need to put that into a proper patch. Best before the next question
pops up. :)

Andreas

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