where is the libvirt.xml ?

[suyi wang <wangsuyi640@xxxxxxxxx>]

Hi all:
      My OS is now Fedora16 , and the spice server is installed on it by rpms. Then I run 'qemu-kvm -hda /root/vaddsoft.img -m 512 -vga qxl -spice port=5930,disable-ticketing' , I want to find out where is the  libvirt.xml for the command .  Well , I mean that the libvirt.xml is genrated automatically,  not by myself manually.
     Wish your help! Thanks a lot!

-- 
Yours.
suyi