Sets the list of cdrom devices that a VM will have.
Usually a VM will start with a single cdrom, named 'cd1'.
cdroms = cd1
But a VM can have other cdroms such as 'unattended' for unattended installs:
variants: - @Linux: unattended_install: cdroms += " unattended"
And 'winutils' for Microsoft Windows VMs:
variants: - @Windows: unattended_install.cdrom, whql.support_vm_install: cdroms += " winutils"
No other documentation currently references this configuration key.