Description of problem:
Devices hotplugged to pci-bridge doesn't show up

Version-Release number of selected component (if applicable):
Host: 3.10.0-589.el7.ppc64le
Guest: 3.10.0-603.el7.ppc64le
qemu-kvm-rhev-2.8.0-5.el7
SLOF-20160223-6.gitdbbfda4.el7.noarch

How reproducible:
3/3

Steps to Reproduce:
1.Boot a guest with a pci-bridge device
/usr/libexec/qemu-kvm 
...
-device pci-bridge,id=pbr,chassis_nr=1 \
...

2.Hotplug a virtio-blk-pci device to the pci-bridge device

{"execute":"__com.redhat_drive_add","arguments":{"file":"/home/test.img","format":"qcow2","id":"test"}}

{"execute":"device_add","arguments":{"driver":"virtio-blk-pci","drive":"test","bus":"pbr","addr":"0xa","id":"blk_dev1"}}

3.Check the new added device inside guest

Actual results:
The device hotplugged didn't show up in the guest or "info qtree" in hmp
[root@localhost ~]# lsblk 
lsblk
NAME                      MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda                         8:0    0  20G  0 disk 
├─sda1                      8:1    0   4M  0 part 
├─sda2                      8:2    0   1G  0 part /boot
└─sda3                      8:3    0  19G  0 part 
  ├─rhel_dhcp70--156-root 253:0    0  17G  0 lvm  /
  └─rhel_dhcp70--156-swap 253:1    0   2G  0 lvm  [SWAP]
[root@localhost ~]# ls /dev/vd* 
ls /dev/vd*
ls: cannot access /dev/vd*: No such file or directory

No new device

Expected results:
It show shows up in guest and "info qtree"

Additional info:
Works on x86 platform