How to install virtiofs drivers on Windows

This document describes how to manually install the virtiofs drivers on Windows.

This document assumes you have a guest with a virtiofs device. Documentation for configuring virtiofs devices in libvirt is here.

Prerequisites

A guest running Microsoft Windows
WinFsp - Windows File System Proxy
virtiofs PCI device driver
virtiofs service

Installing WinFsp

Download and run the latest stable version of the WinFsp installer:

In the installer the default selected options are sufficient unless you plan to develop your own user-mode file system (or contibute to virtiofs for Windows).

You should not need to reboot unless WinFsp was already running on your system.

Installing the virtiofs PCI device driver

Start Computer Managenment and locate the virtiofs PCI device in the "Device Manager" tool. It should appear as a "Mass Storage Controller" under "Other devices".

Right-click on the device and select "Update driver" from the pop-up menu. From the "Update Drivers" dialog choose "Browse my computer for drivers" and fill in the appropriate directory where the drivers files are located. If your operating system does not include a virtio-win driver ISO you can download it here.

Installing the virtiofs service

Run a Command Prompt (not a PowerShell that will think 'sc' means 'Set-Content') as administrator and execute the following command in order to register virtiofs as a service which starts automatically when Windows loads.

C:\> sc.exe create VirtioFsSvc binpath="(your binary location)\virtiofs.exe" start=auto depend="WinFsp.Launcher/VirtioFsDrv" DisplayName="Virtio FS Service"

A manual service start is done with the following command:

C:\> sc start VirtioFsSvc

virtiofs will use the first available drive letter starting with Z: and downward. Use the "-m" command line parameter to explicitly select a drive letter.