Comment 9 for bug 1735420

Mainline Kernel 4.8 does not seem to have the patch included:

ubuntu@ubu-vm-01:~$ uname -a
Linux ubu-vm-01 4.8.0-040800-generic #201610022031 SMP Mon Oct 3 02:27:31 UTC 2016 s390x s390x s390x GNU/Linux
ubuntu@ubu-vm-01:~$ kvm-ok
INFO: /dev/kvm exists
KVM acceleration can be used
ubuntu@ubu-vm-01:~$ ls -la /dev/kvm
crw------- 1 root root 10, 232 Mar 20 05:16 /dev/kvm

Knowing that it is in 4.13, I tried mainline 4.10 as well and - yes - it must have the patch:

ubuntu@ubu-vm-01:~$ uname -a
Linux ubu-vm-01 4.10.0-041000-generic #201702191831 SMP Mon Feb 20 00:15:43 UTC 2017 s390x s390x s390x GNU/Linux
ubuntu@ubu-vm-01:~$ kvm-ok
INFO: /dev/kvm does not exist
HINT: sudo modprobe kvm
INFO: For more detailed results, you should run this as root
HINT: sudo /usr/sbin/kvm-ok
ubuntu@ubu-vm-01:~$ ls -la /dev/kvm
ls: cannot access '/dev/kvm': No such file or directory
ubuntu@ubu-vm-01:~$

So looks like the patch came in with either 4.9 or 4.10 (probably 4.10).