Comment # 3 on bug 926539 from Dr. Werner Fink

(In reply to Bernhard Wiedemann from comment #2)

> unfortunately that would not work on SLE-11-SP3
> and we dont want to maintain two versions of our script.

This is not a problem of systemd, but you may do
something like

  if type -p systemctl > /dev/null 2>&1 ; then
     systemctl enable libvirtd.service
  else
     chkconfig -a libvirtd
  fi

also a check like

  /usr/bin/mountpoint -q /sys/fs/cgroup/systemd

does tell you if systemd is active.  Nevertheless SysVinit boot scripts for
SUSE packages are deprecated!