I have the same problem. In dmesg on virtualization host I see lines like next one:
[ 893.703227] type=1400 audit(1442496602.701:39): apparmor="DENIED" operation="signal" profile="/sbin/dhclient" pid=1510 comm="libvirtd" requested_mask="receive" denied_mask="receive" signal=term peer="/usr/sbin/libvirtd"
I have the same problem. In dmesg on virtualization host I see lines like next one:
[ 893.703227] type=1400 audit(144249660 2.701:39) : apparmor="DENIED" operation="signal" profile= "/sbin/ dhclient" pid=1510 comm="libvirtd" requested_ mask="receive" denied_ mask="receive" signal=term peer="/ usr/sbin/ libvirtd"