During VM boot we see an error from piix4_smbus
and in dmesg something like:
piix4_smbus 0000:00:07.3: Host SMBus controller not enabled!
This error is caused by VM having no smbus but Ubuntu always trying to load the module. It doesn’t affect anything but is a bit annoying. Originally this error was reported on VirtualBox and Ubuntu 10.10, but I still see it in Ubuntu 13.10. It also exist on VMware Fusion.