ubuntu@s1lp13:~$ apt-cache policy qemu
qemu:
  Installed: 1:4.2-3ubuntu6.20
  Candidate: 1:4.2-3ubuntu6.20
  Version table:
 *** 1:4.2-3ubuntu6.20 500
        500 http://us.ports.ubuntu.com/ubuntu-ports focal-proposed/main s390x Packages
        100 /var/lib/dpkg/status
     1:4.2-3ubuntu6.19 500
        500 http://ports.ubuntu.com/ubuntu-ports focal-updates/main s390x Packages
     1:4.2-3ubuntu6.17 500
        500 http://ports.ubuntu.com/ubuntu-ports focal-security/main s390x Packages
     1:4.2-3ubuntu6 500
        500 http://ports.ubuntu.com/ubuntu-ports focal/main s390x Packages
ubuntu@s1lp13:~$ qemu-system-s390x --version
QEMU emulator version 4.2.1 (Debian 1:4.2-3ubuntu6.20)
Copyright (c) 2003-2019 Fabrice Bellard and the QEMU Project developers
ubuntu@s1lp13:~$ virsh list --all
 Id   Name        State
----------------------------
 -    ubu-vm-01   shut off

ubuntu@s1lp13:~$ virsh start ubu-vm-01
Domain ubu-vm-01 started

ubuntu@s1lp13:~$ virsh list --all
 Id   Name        State
---------------------------
 2    ubu-vm-01   running

ubuntu@s1lp13:~$ sudo ls /sys/kernel/debug/s390dbf/
0.0.2600  cio_msg	ctc_setup  kvm-trace  mpc_trace      qdio_error		 qeth_setup
ap	  cio_trace	ctc_trace  kvm-uv     pci_error      qdio_setup		 vfio_ccw_msg
chsc_log  cpum_cf_diag	dasd	   lgr	      pci_msg	     qeth_card_0.0.c000  vfio_ccw_trace
chsc_msg  cpum_sf	eadm_log   mpc_error  pkey	     qeth_control	 zcrypt
cio_crw   ctc_error	kvm-1479   mpc_setup  qdio_0.0.c002  qeth_msg
ubuntu@s1lp13:~$ sudo grep cpnc /sys/kernel/debug/s390dbf/kvm-1479/sprintf 
00 01643802096:152945 3 - 02 000000013fa231c4  00[0000000180000000-000000003fe007d0]: setting cpnc to 0
00 01643802097:839787 3 - 08 000000013fa231c4  00[0000000180000000-000000003fe02660]: setting cpnc to 0
00 01643802097:853108 3 - 10 000000013fa231c4  00[0000000180000000-0000000000010000]: setting cpnc to 0
00 01643802097:936371 3 - 10 000000013fa231c4  00[0000200180000000-0000000031852d02]: setting cpnc to 4
00 01643802098:004216 3 - 12 000000013fa231c4  01[0000c00180000000-0000000031107b0c]: setting cpnc to 0
ubuntu@s1lp13:~$