Description of problem:
<seclabel model='dac' relabel='no'/> does not work, the owner and the group of
the file are still changed to qemu:qemu.

Version-Release number of selected component (if applicable):
libvirt-daemon-1.1.1-2.fc19.x86_64.rpm

How reproducible:
Every time

Steps to Reproduce:
1. Create a virtual machine
2. Attach a CD image to it:
    # virsh dumpxml test
        ...
        <disk type='file' device='cdrom'>
          <driver name='qemu' type='raw'/>
          <source file='/mnt/extra/Software/Linux/Fedora/Fedora-Live-Desktop-x86_64-19/Fedora-Live-Desktop-x86_64-19-1.iso'>
            <seclabel model='selinux' relabel='no'/>
            <seclabel model='dac' relabel='no'/>
          </source>
          <target dev='hdc' bus='ide'/>
          <readonly/>
          <shareable/>
          <address type='drive' controller='0' bus='1' target='0' unit='0'/>
        </disk>

3. Start the machine:
    # ls -lZ Fedora-Live-Desktop-x86_64-19-1.iso 
    -r--r--r--. root root system_u:object_r:public_content_t:s0 Fedora-Live-Desktop-x86_64-19-1.iso

    # virsh start test
    Domain test started

Actual results:
# ls -lZ Fedora-Live-Desktop-x86_64-19-1.iso 
-r--r--r--. qemu qemu system_u:object_r:public_content_t:s0 Fedora-Live-Desktop-x86_64-19-1.iso

Expected results:
The owner & group shouldn't be changed.

Additional info:
https://www.redhat.com/archives/libvirt-users/2013-August/msg00100.html