Description of problem:
After created the VM, added a network interface and have changed its type, the VM cannot be started.


Version-Release number of selected component (if applicable):
oVirt Engine Version: 3.4


How reproducible:
100%


Steps to Reproduce:
1. Create a PPC64 cluster
2. Add a PPC64 host
3. Create a VM using the PPC64 host
4. Add a Network Interface to the VM using the sPAPR VLAN type
5. Run the VM.
6. Shutdown the VM.
7. Edit the Network inteface type, created on step 4, to any other.
8. Run the VM.

Actual results:
VM failed to run and the message is displayed: "VM PPC_VM is down. Exit message: internal error: process exited while connecting to monitor: Warning: Disabling some instructions which are not emulated by TCG (0x0, 0x6) qemu-system-ppc64: -device e1000,netdev=hostnet0,id=net0,mac=00:1a:4a:74:d0:00,reg=0x1000: Property '.reg' not found ."


Expected results:
VM run without errors.


Additional info:
If a new NIC is created, the problem does not appear. Seems there are info related with the last NIC being stored.