On 04/30/2014 05:01 PM, Oleg Bondarev wrote:
Hi,

Can anyone please help with the following: I have a running instance with interface

    <interface type='bridge'>
      <mac address='fa:16:3e:ba:a4:67'/>
      <source bridge='br100/>
      <target dev='vnet0'/>
      <model type='virtio'/>
      <filterref filter='nova-instance-instance-00000001-fa163ebaa467'/>
      <alias name='net0'/>
      <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/>
    </interface>

what I need is to clear network interface on the instance. I tried virsh update-device with following xml:

    <interface type='bridge'>
      <mac address='fa:16:3e:ba:a4:67'/>
      <source bridge='br100/>
      <model type='virtio'/>
    </interface>

but this results in the following error:
$ sudo virsh update-device 13 xml.xml --persistent --live --config
error: Failed to update device from xml.xml
error: End of file while reading data: Input/output error
error: Failed to reconnect to the hypervisor

and libvirt is restarted. Is it possible to clear nw filter at all?

Yes, changing the filterref of the interface of a running domain has been supported since v1.0.1, but you've found a genuine bug! I've reproduced it on my system with the last sources from git, produced a patch to fix it, and posted it to the upstream list:

http://www.redhat.com/archives/libvir-list/2014-May/msg00005.html

Once this is ACKed and pushed, I'll pull it into the maintenance branches back to 1.0.1.

Thanks for reporting this problem!