Comment # 3 on bug 1094898 from Lin Ma

(In reply to Vladimir Vcelak from comment #2)
> When I changed the configuration to older version 42.3 that is
> 
> 1. rename and modify  usr/lib/systemd/system/qemu-ga.service
> 
> rm /usr/lib/systemd/system/qemu-ga@.service
> cat /usr/lib/systemd/system/qemu-ga.service
> [Unit]
> Description=QEMU Guest Agent
> Documentation=http://wiki.qemu.org/Features/GuestAgent
> BindsTo=dev-virtio\x2dports-org.qemu.guest_agent.0.device
> After=dev-virtio\x2dports-org.qemu.guest_agent.0.device
> 
> [Service]
> Type=simple
> ExecStart=-/usr/bin/qemu-ga
> Restart=always
> RestartSec=0
> 
> 2. modify /usr/lib/udev/rules.d/80-qemu-ga.rules
> 
> cat /usr/lib/udev/rules.d/80-qemu-ga.rules
> SUBSYSTEM=="virtio-ports", ATTR{name}=="org.qemu.guest_agent.0",
> TAG+="systemd", ENV{SYSTEMD_WANTS}+="qemu-ga.service"
> 
> so it's okay.

It can't be fixed that way, Please refer to bsc#1089067