[libvirt] Network not Persistent

Hello All, I am currently working on patches for PCI-passthrough of SRIOV VF's and I am facing an issue with the network definition not being persistent. I am using a new forward mode = hostdev and the network xml is as follows: <network> <name>pci-passthrough-network</name> <uuid>81ff0d90-c91e-6742-64da-4a736edb9a8f</uuid> <forward mode="hostdev"> <pf dev="eth2"/> </forward> </network> Command line used is: # virsh net-define pci_passthrough_network.xml The network is defined successfully and I can use it at this point. But if I restart libvirt after defining the above network, I lose the network definition. After restart libvirt does not possess any knowledge of the above network. This does not happen when I use forward mode="bridge". I have cross referenced the function call path of networkDefine for both the forwarding modes and I can't seem to find the problem. Is there some function I am missing? May I ask for your help to solve this issue? Many Thanks, Regards, Shradha Shah