Created attachment 1198571 [details]
set boot from virtio disk, but in fact it boot from network

Description of problem:
Guest use OVMF, and set <boot order='1'/> for interface, it will boot from network. After change the <boot order='1'/> into virtio disk, do destroy-start, the guest will still boot from network.

Version-Release number of selected component (if applicable):
libvirt-2.0.0-6.el7.x86_64
ipxe-roms-qemu-20160127-5.git6366fa7a.el7.noarch.rpm
OVMF-20160608-3.git988715a.el7.noarch
qemu-kvm-rhev-2.6.0-22.el7.x86_64

How reproducible:
100%

Steps to Reproduce:
1. prepare a guest with virtio disk. set it boot from network. It will boot from network. see interfaceboot.log.
  <os>
    <type arch='x86_64' machine='pc-q35-rhel7.3.0'>hvm</type>
    <loader readonly='yes' type='pflash'>/usr/share/OVMF/OVMF_CODE.secboot.fd</loader>
    <nvram>/var/lib/libvirt/qemu/nvram/uefiq35notset_VARS.fd</nvram>
  </os>
...
    <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2'/>
      <source file='/var/lib/libvirt/images/uefiq35notset.qcow2'/>
      <target dev='vda' bus='virtio'/>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x04' function='0x0'/>
    </disk>
...
    <interface type='bridge'>
      <mac address='52:54:00:97:99:85'/>
      <source bridge='br0'/>
      <model type='rtl8139'/>
      <boot order='1'/>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x06' function='0x0'/>
    </interface>
...

2. destroy the guest, edit it the boot device to disk, it will still boot from network. see ovmf log virtiodiskboot.log.

 <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2'/>
      <source file='/var/lib/libvirt/images/uefiq35notset.qcow2'/>
      <target dev='vda' bus='virtio'/>
<boot order='1'/>
      <address type='pci' domain='0x0000' bus='0x02' slot='0x04' function='0x0'/>
    </disk>
...

3. change the disk to sata type, will boot from disk. see ovmf log satadiskboot.log.
  <disk type='file' device='disk'>
      <driver name='qemu' type='qcow2'/>
      <source file='/var/lib/libvirt/images/uefiq35notset.qcow2'/>
      <target dev='sda' bus='scsi'/>
      <boot order='1'/>
      <address type='drive' controller='0' bus='0' target='0' unit='0'/>
    </disk>
...
4. change the disk back to virtio type, it will boot from disk and works well. see ovmf log virtiodiskboot2.log.


Actual results:
After change first boot device from network to virtio disk, the guest still boot from network. 

Expected results:
The boot order should match what we set in the domain xml.

Additional info:
sata and scsi disk have no such issue.