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

["Michael S. Tsirkin" <mst@redhat.com>]

On Thu, Feb 19, 2015 at 12:36:37PM +0300, Denis V. Lunev wrote:
> 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.

But why doesn't it?
Seems like an obvious omission?

-- 
MST