Description of problem:
  Migration will never end after hot-unplug virtual nic.
  The following testing results base on local migration (on the same client)

Version-Release number of selected component (if applicable):
kernel version-
2.6.32-133.el6.x86_64
qemu-kvm version -
qemu-kvm-0.12.1.2-2.158.el6.x86_64
host:AMD
How reproducible:
90%

Steps to Reproduce:
1.boot guest (A) with this command line -

 /usr/libexec/qemu-kvm -M rhel6.1.0 -enable-kvm -m 1024 -smp 2,sockets=2,cores=1,threads=1 -name test -uuid ac0c4b71-6c1a-c864-b844-774ff5663b94 -rtc base=localtime -boot c -drive file=/home/A.qcow2,if=none,id=drive-virtio-disk0,format=qcow2,cache=none -device virtio-blk-pci,bus=pci.0,addr=0x7,drive=drive-virtio-disk0,id=virtio-disk0 -netdev tap,id=hostnet0,vhost=on -device virtio-net-pci,netdev=hostnet0,id=net0,mac=52:54:00:a7:95:ab,bus=pci.0,addr=0x3 -netdev tap,id=hostnet1,vhost=on -device virtio-net-pci,netdev=hostnet1,id=net1,mac=52:54:00:a6:53:ea,bus=pci.0,addr=0x4 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -usb -device usb-tablet,id=input0 -spice port=5910,disable-ticketing -vga qxl -device intel-hda,id=sound0,bus=pci.0,addr=0x5 -device hda-duplex,id=sound0-codec0,bus=sound0.0,cad=0 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x6 -monitor stdio

2.from monitor 
(qemu) netdev_del hostnet0
(qemu) device_del net0

3.boot destination (B) with the following command line -

  /usr/libexec/qemu-kvm -M rhel6.1.0 -enable-kvm -m 1024 -smp 2,sockets=2,cores=1,threads=1 -name test -uuid ac0c4b71-6c1a-c864-b844-774ff5663b94 -rtc base=localtime -boot c -drive file=/home/A.qcow2,if=none,id=drive-virtio-disk0,format=qcow2,cache=none -device virtio-blk-pci,bus=pci.0,addr=0x7,drive=drive-virtio-disk0,id=virtio-disk0 -netdev tap,id=hostnet1,vhost=on -device virtio-net-pci,netdev=hostnet1,id=net1,mac=52:54:00:a6:53:ea,bus=pci.0,addr=0x4 -chardev pty,id=charserial0 -device isa-serial,chardev=charserial0,id=serial0 -usb -device usb-tablet,id=input0 -spice port=5911,disable-ticketing -vga qxl -device intel-hda,id=sound0,bus=pci.0,addr=0x5 -device hda-duplex,id=sound0-codec0,bus=sound0.0,cad=0 -device virtio-balloon-pci,id=balloon0,bus=pci.0,addr=0x6 -monitor stdio -incoming tcp:0:5888

4.In A's monitor -
  (qemu) migrate -d tcp:0:5888

Actual results:
  Please pay attention to the value of 'remaining ram',the value will reduce to 88k/72K/64k.But the migration never end.
  (qemu) info migrate 
Migration status: active
transferred ram: 1198948 kbytes
remaining ram: 15900 kbytes
total ram: 1180040 kbytes
(qemu) info migrate 
Migration status: active
transferred ram: 1253196 kbytes
remaining ram: 11616 kbytes
total ram: 1180040 kbytes
(qemu) info migrate 
Migration status: active
transferred ram: 1266776 kbytes
remaining ram: 64 kbytes
total ram: 1180040 kbytes
(qemu) info migrate 
Migration status: active
transferred ram: 1276808 kbytes
remaining ram: 88 kbytes
total ram: 1180040 kbytes
(qemu) info migrate 
Migration status: active
transferred ram: 1281676 kbytes
remaining ram: 88 kbytes
total ram: 1180040 kbytes
(qemu) info migrate 
Migration status: active
transferred ram: 1284816 kbytes
remaining ram: 88 kbytes
total ram: 1180040 kbytes
(qemu) info migrate 
Migration status: active
transferred ram: 1292208 kbytes
remaining ram: 64 kbytes
total ram: 1180040 kbytes
(qemu) info migrate 
Migration status: active
transferred ram: 1294180 kbytes
remaining ram: 72 kbytes
total ram: 1180040 kbytes
(qemu) info migrate 
Migration status: active
transferred ram: 1296168 kbytes
remaining ram: 72 kbytes
total ram: 1180040 kbytes
(qemu) info migrate 
Migration status: active
transferred ram: 1300608 kbytes
remaining ram: 88 kbytes
total ram: 1180040 kbytes

  


Expected results:
Migration can finished successfully.


Additional info: