Description of problem:
As subject

Version-Release number of selected component (if applicable):
libvirt-3.2.0-5.el7.x86_64
qemu-kvm-rhev-2.9.0-6.el7.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Start a q35 VM:
# virsh start test --console

2. Attach a virtio disk to pcie-root-port of pcie-root-port model:
# virsh attach-disk test /exports/raw vdb --address pci:0000.09.00.0
Disk attached successfully

The pcie-root-port:
  <controller type='pci' index='9' model='pcie-root-port'>
      <model name='pcie-root-port'/>
      <target chassis='9' port='0x14'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x4'/>
    </controller>

3. Migrate the VM to another host:
# virsh migrate test qemu+ssh://xxxx/system --verbose --unsafe
Migration: [100 %]

4. In destination host, try to detach the disk by hmp command:
# virsh qemu-monitor-command test --hmp info block
drive-virtio-disk0 (#block157): /exports/test-1.qcow2 (qcow2)
    Cache mode:       writeback

drive-virtio-disk1 (#block303): /exports/raw (raw)
    Cache mode:       writeback

# virsh qemu-monitor-command test --hmp device_del virtio-disk1

# virsh qemu-monitor-command test --hmp info block             
drive-virtio-disk0 (#block157): /exports/test-1.qcow2 (qcow2)
    Cache mode:       writeback

drive-virtio-disk1 (#block303): /exports/raw (raw)
    Cache mode:       writeback

Detach failed but return success.

Actual results:
As step 4

Expected results:
Detach success.

Additional info:
The bug is not reproduced on pcie downstream port and ioh3420 model pcie-root-port.
Since default pcie-root-port works well in RHEL7.3, mark it as regression.