[RHEL7/s390] systemd-modules-load fails at boot with error message "Failed to insert 'pkey': No such device"

Issue

• When booting a zVM system, systemd-modules-load service fails with error message shown below:

  systemd[1]: systemd-modules-load.service: main process exited, code=exited, status=1/FAILURE
  systemd[1]: Failed to start Load Kernel Modules.
  systemd[1]: Unit systemd-modules-load.service entered failed state.
  

• Examining the journal for the boot shows the error message shown below:

  # journalctl -b -p err | grep "systemd-modules-load"
  [...] systemd-modules-load[84]: Failed to insert 'pkey': No such device
  [...] systemd-modules-load[1092]: Failed to insert 'pkey': No such device