[ovirt-users] before_vdsm_start hook will be saved ?

Hey folks I have a ovirt-4.3 environment, where i have a before_vdsm_start hook to change default usb2 device to usb3(qemu-xhci). But i noticed that the vm still uses the usb3 device after i removed the before_vdsm_start hook. So i wonder if the xml updated by before_vdsm_start hook will be saved the disk/databse, if so how i can reset it to the original. Thanks