Description of problem:
virt-manager add macvtap device  , even choose "NO" in the GUI option

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

libvirt-0.10.0-0rc0.el6.x86_64
virt-manager-0.9.0-14.el6.x86_64


How reproducible:
100%

Steps to Reproduce:
1. start a domain
2.  run virt-manager  => Add Hardware => Network  => choose Host device eth0:macvtap => Finish
pop up warning message:
"Are you sure want to add this device"
"This device could not be attached to the running machine. Would you like to make the device available after the next guest shutdown?"
NO  or YES

3.  choose NO

4. check the host net device

5.# ip add
1: lo: <LOOPBACK,UP,LOWER_UP> mtu 16436 qdisc noqueue state UNKNOWN
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
    inet 127.0.0.1/8 scope host lo
    inet6 ::1/128 scope host
       valid_lft forever preferred_lft forever
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP qlen 1000
    link/ether 00:23:ae:8f:f2:b3 brd ff:ff:ff:ff:ff:ff
    inet 10.66.82.251/23 brd 10.66.83.255 scope global eth0
    inet6 fe80::223:aeff:fe8f:f2b3/64 scope link
       valid_lft forever preferred_lft forever
3: virbr0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc noqueue state UNKNOWN
    link/ether 52:54:00:ed:7d:b4 brd ff:ff:ff:ff:ff:ff
    inet 192.168.122.1/24 brd 192.168.122.255 scope global virbr0
4: virbr0-nic: <BROADCAST,MULTICAST> mtu 1500 qdisc noop state DOWN qlen 500
    link/ether 52:54:00:ed:7d:b4 brd ff:ff:ff:ff:ff:ff
133: macvtap0@eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 500
    link/ether 52:54:00:54:61:42 brd ff:ff:ff:ff:ff:ff
    inet6 fe80::5054:ff:fe54:6142/64 scope link
       valid_lft forever preferred_lft forever






Actual results:
macvtap device always add

Expected results:
choose NO do not add the device

Additional info:
1.I found  the macvtap device will create once you click "Finish"  , actually device has created  before you choose Yes or No.