4.2.

hostnamectl | grep "Operating System"
yum module list --installed

# hostnamectl | grep "Operating System"
Operating System: Red Hat Enterprise Linux 8.5 (Ootpa)
# yum module list --installed
[...]
Advanced Virtualization for RHEL 8 IBM Z Systems (RPMs)
Name                Stream                  Profiles                  Summary
virt                av [e]                common [i]                Virtualization module

yum module info virt

# yum module info virt

Name             : virt
Stream           : rhel [d][e][a]
Version          : 8050020211203195115
[...]