Re: [Qemu-devel] [PATCH] qdev: Fix device_add bus assumptions

["Andreas Färber" <afaerber@suse.de>]

Hi,

Am 22.04.2013 13:51, schrieb Libaiqing:
>   When I use the config below,an error occurs.Is there anything wrong?
> 
>   Qemu-kvm -enable-kvm -name win7 -M pc-0.15 -m 1024 -smp 2 -boot c  -device virtio-serial-pci,id=virtio-serial0,bus=pci.0,addr=0x4 -chardev spicevmc,id=charchannel0,name=vdagent -device virtserialport,bus=virtio-serial0.0,chardev=charchannel0,id=channel0,name=com.redhat.spice.0  -drive file=/home/img/win7.qed,if=virtio,index=0,format=qed  -monitor stdio   -vga qxl  -vnc :1
> 
> Error output:
>     -device virtserialport,bus=virtio-serial0.0,chardev=charchannel0,id=channel0,name=com.redhat.spice.0: Bus 'virtio-serial0.0' is full
>     -device virtserialport,bus=virtio-serial0.0,chardev=charchannel0,id=channel0,name=com.redhat.spice.0: Bus 'virtio-serial0.0' not found
> 
> Any feedback are appliciated.

This does not sound related to this patch at all...

Instead it sounds as if the virtio refactorings had some effect not only
on virtio-net but also on virtio-serial. Fred?

Andreas

> -----Original Message-----
> From: qemu-devel-bounces+libaiqing=huawei.com@nongnu.org [mailto:qemu-devel-bounces+libaiqing=huawei.com@nongnu.org] On Behalf Of Igor Mammedov
> Sent: Thursday, April 18, 2013 5:02 PM
> To: Igor Mammedov
> Cc: ehabkost@redhat.com; qemu-devel@nongnu.org; armbru@redhat.com; anthony@codemonkey.ws; pbonzini@redhat.com; lcapitulino@redhat.com; Andreas Färber
> Subject: Re: [Qemu-devel] [PATCH] qdev: Fix device_add bus assumptions
> 
> On Thu, 18 Apr 2013 10:41:56 +0200
> Igor Mammedov <imammedo@redhat.com> wrote:
> 
> [...]
>>> -    if (!bus) {
>>> -        bus = sysbus_get_default();
>>> -    }
>>> -
>> I've checked all direct childs of TYPE_DEVICE and they all set k->bus_type,
>> with only one exception of TYPE_CPU. So it should be safe to remove fallback
>> from qdev_device_add POV.
>> However  TYPE_CPU breaks assumption that device always has parent_bus set
>> to not NULL in qdev_unplug() and qdev_print()
> Err, qdev_print() is safe since it's called on bus children only, so it has
> parent_bus.
> 
>>
>> It would be better to add something like this:
>> // untested
>>
>> diff --git a/hw/core/qdev.c b/hw/core/qdev.c
>> index 4eb0134..45009ba 100644
>> --- a/hw/core/qdev.c
>> +++ b/hw/core/qdev.c
>> @@ -207,7 +207,7 @@ void qdev_unplug(DeviceState *dev, Error **errp)
>>  {
>>      DeviceClass *dc = DEVICE_GET_CLASS(dev);
>>  
>> -    if (!dev->parent_bus->allow_hotplug) {
>> +    if (dev->parent_bus && !dev->parent_bus->allow_hotplug) {
>>          error_set(errp, QERR_BUS_NO_HOTPLUG, dev->parent_bus->name);
>>          return;
>>      }
>> diff --git a/qdev-monitor.c b/qdev-monitor.c
>> index 9a78ccf..2476e4e 100644
>> --- a/qdev-monitor.c
>> +++ b/qdev-monitor.c
>> @@ -557,7 +557,9 @@ static void qdev_print(Monitor *mon, DeviceState *dev,
>> int indent) qdev_print_props(mon, dev, DEVICE_CLASS(class)->props, indent);
>>          class = object_class_get_parent(class);
>>      } while (class != object_class_by_name(TYPE_DEVICE));
>> -    bus_print_dev(dev->parent_bus, mon, dev, indent);
>> +    if (dev->parent_bus) {
>> +        bus_print_dev(dev->parent_bus, mon, dev, indent);
>> +    }
>>      QLIST_FOREACH(child, &dev->child_bus, sibling) {
>>          qbus_print(mon, child, indent);
>>      }
>>
>>>      /* create device, set properties */
>>>      qdev = DEVICE(object_new(driver));
>>> -    qdev_set_parent_bus(qdev, bus);
>>> +
>>> +    if (bus) {
>>> +        qdev_set_parent_bus(qdev, bus);
>>> +    }
>>>  
>>>      id = qemu_opts_id(opts);
>>>      if (id) {
>>
>>
> 
> 


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