When you run your Debian or Ubuntu under Microsoft's Hyper-V, you may encounter the following error at startup.
piix4_smbus 0000:00:07.3: SMBus base address uninitialized - upgrade BIOS or use force_addr=0xaddr
Since error is beacuse of absense of smbus, you can fix the annoying error by using the following instructions.
First check if the module is loaded
lsmod | grep i2c_piix4
If it is loaded (if you have the error it must be loaded), open the file
/etc/modprobe.d/blacklist.conf file with your favorite text editor
Then append the following line to the file and save it.
After all, run this to update the initramfs
update-initramfs -u -k all
After rebooting you will not see the same error message or you can check it with
dmesg (to see boot messages)