[libvirt] BUG: attaching - detaching network device only works 7 times

With the current tip: While extending a test case I found that attaching and detaching the following network device works only 7 times with the below script: <interface type='bridge'> <source bridge='static'/> <mac address='52:54:00:4d:a2:58'/> <target dev='attach0'/> </interface> let c=1; while test 1; do virsh attach-device acl attach.xml ; virsh detach-device acl attach.xml; echo ${c}; let c=c+1; done Then the following error occurs: error: Failed to attach device from attach.xml error: operation failed: parsing pci_add reply failed: Too Many NICs failed to add macaddr=52:54:00:4d:a2:58,vlan=1,name=net1 It looks like the detachment of the device is not done by qemu? Regards, Stefan