Likely, you’ve already grappled with the issue of Hyper-V serial port passthrough in Windows 10.
This problem may seem tricky to tackle as even the official Microsoft’s Deployment guide on Hyper-V can’t offer you any workable solution.
Sure thing, on your guest machine, you can connect its COM ports to a named pipe but that method won’t work for the host’s COM ports unless you manage to use some ancient projects from third-party developers.
Keep on reading to find out more about said solutions and another, much easier and more reliable way to set up Hyper-V COM port redirection from the host to a guest PC.
With FlexiHub, you can make your host’s COM port accessible via the TCP/IP protocol so that any VM running on Hyper-V can be connected to that COM port in a couple of clicks.
The software works by using the network to establish a virtual connection to map serial ports to Hyper-V guest virtual machines. There are no complicated configuration procedures involved: you can implement Hyper-V COM port redirection with just a few simple steps.
To connect the guest COM ports to “named pipes”, the serial interface must be set up from within the Hyper-V session.
Note: This method won’t work for the host’s physical COM port passthrough to a guest system. It’s intended for program debugging only.
Using Hyper-V Manager to connect COM ports
With PipeDream running on your host computer, you can connect a Hyper-V host serial port to a virtual machine. PipeDream acts as a bridge that communicates serial data between a physical COM port and a virtual one on the VM.
You won’t need to install any client-side components or device drivers on your virtual machine, so this method can be used if you still rely on a dated OS (e.g. Windows XP) or some legacy apps.
PipeDream uses Hyper-V's named pipe support for communication, so the network connection is not required. Once you set the pipe name in Hyper-V, a COM port will be instantly accessible from the guest VM through PipeDream.
Another handy project for Microsoft Hyper-V serial port passthrough was created by Albert-Jan Nijburg. Put simply, it can get data from the Hyper-V serial port named pipe and pass it through to some other COM port you choose for that purpose.
It has not been much tested and the project has not been updated for several years, but here you can find a tutorial by Mat Smith that will guide you through PipeToCom:
This detailed guide should have provided you with the knowledge required to add Hyper-V serial port connectivity to your virtual sessions. Once these connections have been established, your virtual machine will enjoy the same functionality as if it had a direct connection to the peripheral serial device.