My kvm / vfio / libvirt / qemu config for a Void Linux host, Windows 11 guest.

Hook scripts are useful as a whole for other Linux guests if dedicating the entire second display to them. Bits might be used in other circumstances.

The objective: make starting and stopping Windows feel like starting any X app and restore my multi-monitor dwm desktops afterwards.

Most modern hardware these days supports the necessary CPU and IOMMU features; there are plenty of tutorials out there on how to configure a system. For the record I'm running desktop workstation on:

* Host OS: Void Linux
* Board: Gigabyte X570 AORUS MASTER, BIOS F35b 09/06/2021
* Intel (for host) and Realtek (passed through) NICs
* CPU: AMD Ryzen 7 3800X 8-Core Processor
* Mem: 62GB (32GB allocated dynamically to VM as transparent hugepages)
* Host GPU: Radeon RX 5600 OEM/5600 XT / 5700/5700 XT
* Guest GPU: GeForce GTX 1660 SUPER
* Host SSD: Sabrent Rocket 1TB (Phison Electronics Corporation E16 PCIe4 NVMe)
* Guest SSD: (for Windows only) Sabrent Rocket 1TB (Phison Electronics
  Corporation E16 PCIe4 NVMe)

Barrier barriers runs as a server (started and stopped in the hook scripts); allows for transparent mouse and clipboard use between the host and guest; you can even add a non-VM client like a laptop or other desktops if you like. My dotfiles repo shows an example config.

Leave a virtual console attached to your new Windows VM so you can set up the Barrier client.

Via pipewire - see the top and bottom of the VM definition in windows.xml for the relevant incantation; in your qemu.conf set user=.

I've generalized my setup with a few variables in kvm.conf; you may find dropping these in may work for you with just a little tweaking.

There's also https://github.com/PassthroughPOST/VFIO-Tools/blob/master/libvirt_hooks/hooks/switch_displays.sh linked appropriately to have ddcutil switch the display inputs between host->guest and back to host when the VM shuts down. That in combination with xrandr sets my dwm displays back to normal, achieving "starting Windows like an X app" convenience.

Some assembly will be required:

# clone this repo, somewhere
cd ~
git clone https://github.com/solutionroute/libvirt-win.git

# link to the hooks directory in the appropriate libvirt
# path for your system
cd /etc/libvirt
sudo ln -s ~/libvirt-win/etc/libvirt/hooks .

It's important that commands within your hook scripts don't fail with an error; this will cause startup to halt and the release scripts to be called.

Testing tip: you can run your hook scripts one by one from the command line in this manner:

/etc/libvirt/hooks/qemu windows start begin