Setting up "Serial ports" in VirtualBox for Fedora guest

1. Run VirtualBox and select the desired VM
2. Select "Serial ports" from the right panel
3. Choose "Port 1" tab
4. Set Port 1 as follows:

Port Number: COM1
Port Mode: Host Device
Port Path: COM1

With this setting you cannot use the serial port COM1 simulataneously from host (Windows) and guest (Fedora).