Secure Execution is a confidential computing technology on s390x (IBM Z
& LinuxONE). Enable the correspondent virtualization technology in QEMU
(where it is referred to as "Protected Virtualization").
- Introduce enableProtection and appendProtectionDevice functions for
QEMU s390x.
- Introduce CheckCmdline to check for "prot_virt=1" being present on the
kernel command line.
- Introduce CPUFacilities and avilableGuestProtection for hypervisor
s390x to check for CPU support.
Fixes: #1771
Signed-off-by: Jakob Naucke <jakob.naucke@ibm.com>
