VirtualMac2,1 is the model identifier used when virtualizing macOS via Apple's Virtualization.framework. This feature is only available on an Apple Silicon Mac host, for an Apple Silicon Mac guest. Intel macOS has never officially supported virtualization, even on an Intel Mac host.
A UniversalMac IPSW is required to restore a newly-created virtual machine with an operating system image. Firmware/Mac can be used to find such an IPSW.
The DeviceTree gives the virtual Mac device a board ID of VMA2MACOSAP, and product name of Apple Virtual Machine 1.[1] While a DeviceTree for VirtualMac1,1 exists in macOS, TSS does not appear to sign any firmware version for it, so it can't be used.
