From: Gonglei <arei.gong...@huawei.com> virtio-$device-{pci, s390, ccw} all duplicate the qdev properties of their virtio child. This approach does not work well with string or pointer properties since we must be careful about leaking or double-freeing them.
Use the QOM alias property to forward property accesses to the VirtIORNG child. This way no duplication is necessary. For their child, object_initialize() leaves the object with a refcount of 1. object_property_add_child() adds its own reference which is dropped again when the property is deleted. The upshot of this is that we always have a refcount >= 1. Upon hot unplug the virtio-$device child is not finalized! Drop our reference after the child property has been added to the parent. Attention please: As Michael's comments, the patches will introduce regresion about "-device FOO,help", which had been fixed by my other patch series: [PATCH v2 0/7] add description field in ObjectProperty and PropertyInfo struct http://lists.nongnu.org/archive/html/qemu-devel/2014-09/msg04908.html Acknowledgements: I copied Stefan's commit c5d49db message about virtio-blk which summarized reasons very well, I cannot agree more with him. Holp Stefan do not mind, thanks! Please review, Thanks a lot! -Gonglei Gonglei (9): virtio-net: use aliases instead of duplicate qdev properties virtio: fix virtio-net child refcount in transports virtio/vhost scsi: use aliases instead of duplicate qdev properties virtio/vhost-scsi: fix virtio-scsi/vhost-scsi child refcount in transports virtio-serial: use aliases instead of duplicate qdev properties virtio-serial: fix virtio-serial child refcount in transports virtio-rng: use aliases instead of duplicate qdev properties virtio-rng: fix virtio-rng child refcount in transports virtio-balloon: fix virtio-balloon child refcount in transports hw/s390x/s390-virtio-bus.c | 16 ++++++++++------ hw/s390x/virtio-ccw.c | 18 +++++++++++------- hw/virtio/virtio-pci.c | 18 +++++++++++------- 3 files changed, 32 insertions(+), 20 deletions(-) -- 1.7.12.4