Information can be put into dmi tables via some qemu-system hosts (x86_64 and aarch64). That information is exposed in Linux under /sys/class/dmi/id and can be read with dmidecode. The names are very annoyingly inconsistent. The point of this doc is to map them.
Example qemu cmdline:
qemu-system-x86_64 -smbios type=<type>,field=value[,...]
qemu-system-x86_64 -smbios type=0,vendor=superco,version=1.2.3