19.2.

*modprobe kvm hpage=1 nested=1*
*dmesg |tail -1*

# *modprobe kvm hpage=1 nested=1*
modprobe: ERROR: could not insert 'kvm': Invalid argument
# *dmesg |tail -1*
[90226.508366] kvm-s390: A KVM host that supports nesting cannot back its KVM guests with huge pages