Description of problem:


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


How reproducible:


Steps to Reproduce:
1. Prepare a shutdown VM with default input device
# virsh domstate test2
shut off

# virsh dumpxml test2 |grep "<input"
    <input type='mouse' bus='ps2'/>
    <input type='keyboard' bus='ps2'/>

2. Prepare a virtio.xml describing related input device
# cat /proc/bus/input/devices |grep  "I: Bus=0003 Vendor=17ef Product=6050 Version=0111" -A11
I: Bus=0003 Vendor=17ef Product=6050 Version=0111
N: Name="Lenovo Precision USB Mouse"
P: Phys=usb-0000:00:1d.0-1.7/input0
S: Sysfs=/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.7/2-1.7:1.0/input/input3
U: Uniq=
H: Handlers=mouse0 event3 
B: PROP=0
B: EV=17
B: KEY=1f0000 0 0 0 0
B: REL=103
B: MSC=10

# cat virtio.xml 
    <input type='mouse' bus='virtio'>
      <source evdev='/dev/input/event3'/>  **illegal**
      <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>
    </input>

3. Cold-unplug virtio.xml to VM
# virsh attach-device test2 virtio.xml --config
Device attached successfully

# virsh dumpxml test2 |grep "<input" -A3
    <input type='mouse' bus='ps2'/>
    <input type='keyboard' bus='ps2'/>
    <input type='mouse' bus='virtio'>
      <source evdev='/dev/input/event3'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>
    </input>

4. Start VM
# virsh start test2
Domain test2 started

# virsh dumpxml test2 |grep "<input" -A4
    <input type='mouse' bus='ps2'>
      <alias name='input0'/>
    </input>
    <input type='keyboard' bus='ps2'>
      <alias name='input1'/>
    </input>
    <input type='mouse' bus='virtio'>
      <source evdev='/dev/input/event3'/>
      <alias name='input2'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x08' function='0x0'/>
    </input>

# ps -ef |grep "test2" |sed 's/-device/\n-device/g'
-device virtio-mouse-pci,id=input2,bus=pci.0,addr=0x8 (No 'source' related info)

Actual results:
As Step-3 and Step-4 show

Expected results:
Extra illegal 'source' element should be detected when saving dumpxml file and be deleted.

Additional info: