s390x/virtio-hcall: Add range check for hypervisor call The handler for diag 500 did not check whether the requested function was in the supported range, so illegal values could crash QEMU in the worst case. Signed-off-by: Thomas Huth <thuth@linux.vnet.ibm.com> Reviewed-by: Cornelia Huck <cornelia.huck@de.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> CC: qemu-stable@nongnu.org