Re: [Qemu-devel] [RESEND PATCH 1/2] balloon: call qdev_alias_all_properties for proxy dev in balloon class init

["Denis V. Lunev" <den@openvz.org>]

On 19/02/15 12:25, Michael S. Tsirkin wrote:
> On Thu, Jan 29, 2015 at 05:24:41PM +0300, Denis V. Lunev wrote:
>> The idea is that all other virtio devices are calling this helper
>> to merge properties of the proxy device. This is the only difference
>> in between this helper and code in inside virtio_instance_init_common.
>> The patch should not cause any harm as property list in generic balloon
>> code is empty.
>>
>> This also allows to avoid some dummy errors like fixed by this
>>      commit 91ba21208839643603e7f7fa5864723c3f371ebe
>>      Author: Gonglei <arei.gonglei@huawei.com>
>>      Date:   Tue Sep 30 14:10:35 2014 +0800
>>      virtio-balloon: fix virtio-balloon child refcount in transports
>>
>> Signed-off-by: Denis V. Lunev <den@openvz.org>
>> Signed-off-by: Raushaniya Maksudova <rmaksudova@parallels.com>
>> Revieved-by: Cornelia Huck <cornelia.huck@de.ibm.com>
>> CC: Christian Borntraeger <borntraeger@de.ibm.com>
>> CC: Anthony Liguori <aliguori@amazon.com>
>> CC: Michael S. Tsirkin <mst@redhat.com>
>> ---
>>   hw/s390x/virtio-ccw.c  | 5 ++---
>>   hw/virtio/virtio-pci.c | 5 ++---
>>   2 files changed, 4 insertions(+), 6 deletions(-)
>>
>> diff --git a/hw/s390x/virtio-ccw.c b/hw/s390x/virtio-ccw.c
>> index ea236c9..82da894 100644
>> --- a/hw/s390x/virtio-ccw.c
>> +++ b/hw/s390x/virtio-ccw.c
>> @@ -899,9 +899,8 @@ static void balloon_ccw_stats_set_poll_interval(Object *obj, struct Visitor *v,
>>   static void virtio_ccw_balloon_instance_init(Object *obj)
>>   {
>>       VirtIOBalloonCcw *dev = VIRTIO_BALLOON_CCW(obj);
>> -    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_BALLOON);
>> -    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
>> -    object_unref(OBJECT(&dev->vdev));
>> +    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
>> +                                TYPE_VIRTIO_BALLOON);
>>       object_property_add(obj, "guest-stats", "guest statistics",
>>                           balloon_ccw_stats_get_all, NULL, NULL, dev, NULL);
>>   
>> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
>> index dde1d73..745324b 100644
>> --- a/hw/virtio/virtio-pci.c
>> +++ b/hw/virtio/virtio-pci.c
>> @@ -1316,9 +1316,8 @@ static void virtio_balloon_pci_class_init(ObjectClass *klass, void *data)
>>   static void virtio_balloon_pci_instance_init(Object *obj)
>>   {
>>       VirtIOBalloonPCI *dev = VIRTIO_BALLOON_PCI(obj);
>> -    object_initialize(&dev->vdev, sizeof(dev->vdev), TYPE_VIRTIO_BALLOON);
>> -    object_property_add_child(obj, "virtio-backend", OBJECT(&dev->vdev), NULL);
>> -    object_unref(OBJECT(&dev->vdev));
>> +    virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
>> +                                TYPE_VIRTIO_BALLOON);
>>       object_property_add(obj, "guest-stats", "guest statistics",
>>                           balloon_pci_stats_get_all, NULL, NULL, dev,
>>                           NULL);
> OK, but what about this guest-stats property?
> Should it get the same treatment?
>
>> -- 
>> 1.9.1
hmm, IMHO no. init_common is actually do the following

void virtio_instance_init_common(Object *proxy_obj, void *data,
                                  size_t vdev_size, const char *vdev_name)
{
     DeviceState *vdev = data;

     object_initialize(vdev, vdev_size, vdev_name);
     object_property_add_child(proxy_obj, "virtio-backend", 
OBJECT(vdev), NULL);
     object_unref(OBJECT(vdev));
     qdev_alias_all_properties(vdev, proxy_obj);
}

on the other hand there is the following code in s390

static void s390_virtio_net_instance_init(Object *obj)
{
     VirtIONetS390 *dev = VIRTIO_NET_S390(obj);

     virtio_instance_init_common(obj, &dev->vdev, sizeof(dev->vdev),
                                 TYPE_VIRTIO_NET);
     object_property_add_alias(obj, "bootindex", OBJECT(&dev->vdev),
                               "bootindex", &error_abort);
}

which does not contain guest-stats property.