You can check the version of KVM (qemu-kvm) installed on a Linux system by using the following command:
kvm --version
or
qemu-kvm --version
This will print the version number of the installed KVM (qemu-kvm) package. The output should look something like this:
QEMU emulator version 4.2.0 (Debian 1:4.2-2ubuntu2)
Copyright (c) 2003-2021 Fabrice Bellard and the QEMU Project developers
Note that the exact output may vary depending on your Linux distribution and the version of KVM (qemu-kvm) installed.