TW 20151218 with new xen-4.6 and new pvops kernel. Looks like some other
systemd unit file prevents startup of xenstored.

...
[    0.000000] Linux version 4.3.3-1-default (geeko@buildhost) (gcc version
5.2.1 20151008 [gcc-5-branch revision 228597] (SUSE Linux) ) #1 SMP PREEMPT Wed
Dec 16 08:03:35 UTC 2015 (db72752)
...
[   12.312605] systemd-journald[153]: Received SIGTERM from PID 1 (systemd).
[   15.332895] systemd[1]: sockets.target: Found dependency on
proc-xen.mount/start
[   15.344882] systemd[1]: sockets.target: Found dependency on
xen-dom0-modules.service/start
[   15.356892] systemd[1]: sockets.target: Found dependency on
basic.target/start
[   15.368884] systemd[1]: sockets.target: Found dependency on
sockets.target/start
[   15.380884] systemd[1]: sockets.target: Breaking ordering cycle by deleting
job xenstored.socket/start
[   15.392891] systemd[1]: xenstored.socket: Job xenstored.socket/start deleted
to break ordering cycle starting with sockets.target/start
[   15.404903] systemd[1]: sockets.target: Found ordering cycle on
sockets.target/start
[   15.416887] systemd[1]: sockets.target: Found dependency on
xenstored_ro.socket/start
[   15.428883] systemd[1]: sockets.target: Found dependency on
var-lib-xenstored.mount/start
[   15.440880] systemd[1]: sockets.target: Found dependency on
proc-xen.mount/start
[   15.452881] systemd[1]: sockets.target: Found dependency on
xen-dom0-modules.service/start
[   15.464882] systemd[1]: sockets.target: Found dependency on
basic.target/start
[   15.476882] systemd[1]: sockets.target: Found dependency on
sockets.target/start
[   15.488882] systemd[1]: sockets.target: Breaking ordering cycle by deleting
job xenstored_ro.socket/start
[   15.500883] systemd[1]: xenstored_ro.socket: Job xenstored_ro.socket/start
deleted to break ordering cycle starting with sockets.target/start
[   15.502645] systemd[1]: Stopped Switch Root.
[   15.503494] systemd[1]: Cannot find unit for notify message of PID 153.
...

As a result 'xl list' hangs after fresh startup.