VirtualBox

The pbase-preconfig-virtualbox package install the dependencies and adds the KERN_DIR and KERN_VER environment variables required to run VirtualBox and build the guest extensions.

First, place your username in a text file in the /root directory with this echo command below.

echo "mydesktopusername" > /root/DEFAULT_DESKTOP_USERNAME.txt

yum -y install https://pbase-foundation.com/pbase-repo.rpm
yum -y install pbase-preconfig-virtualbox

Reboot after doing this to load in the new environment variables.

Setup VirtualBox Guest

After rebooting verify correct $KERN_DIR after install with these commands to check the $KERN_DIR in the .bashrc'

ls -l $KERN_DIR
echo $KERN_VER

1: Reboot your guest VM to activate the VirtualBox environment variables
2: Select the 'Insert the VirtualBox Guest Additions CD Image' menu item
3: Click the 'Run' dialog button when prompted to rebuild the guest kernel
4: Reboot your guest VM to see the Guest Additions running

Setup VirtualBox Host

yum -y install VirtualBox-7.0
/usr/lib/virtualbox/vboxdrv.sh setup
usermod -a -G vboxusers yourdesktopusername

Then, logged in as your regular desktop user launch virtualbox with:
VirtualBox

More about VirtualBox

Read more about the VirtualBox project at:
https://www.virtualbox.org/