z/VM processor mode

[Quay, Jonathan (IHG)]

We moved a z/VM 5.3 703 system from a z/990 to a z/10.  IPLed
successfully.  When we attempted to IPL our TPF 4.1 guests, they would
go through rollcall and then take an "HCP1455E CPU XX is not started
because it is in check-stop state."  It turns out that the z/OS sysprog
who set up the LPAR had chosen "Z/VM" as the processor mode without
realizing exactly what that meant.