Virt-Manager / KVM

This guide covers setting up a Windows 11 VM using virt-manager with KVM/QEMU, VirtIO drivers, and SPICE GL acceleration via the AMD iGPU. It’s a solid open-source option for everyday office work.

Windows 11 Enterprise ISO

Option 1: Evaluation (90-day trial)

Download evaluation ISO (~6.6 GB) from Microsoft:

microsoft.com/en-us/evalcenter/download-windows-11-enterprise

90 days free, no bloatware, no mandatory Microsoft account.

Option 2: Media Creation Tool + Activation Script

Use the official Windows 11 Media Creation Tool with an activation method:

1. Download Windows 11 Media Creation Tool
2. Create installation media on a USB drive or ISO file
3. Use MAS (Microsoft Activation Scripts) for activation:
   • Open PowerShell as Administrator in Windows
   • Run: irm https://get.activated.win | iex
   • Select the appropriate activation method for your setup
   • No 90-day limit, full Windows 11 experience

Option 3: AtlasOS (Optimized for Performance)

AtlasOS creates a minified Windows 11 ISO with bloatware removed and unnecessary services disabled, resulting in significantly better performance in a VM.

Creating an AtlasOS ISO:

• From a Windows machine: Download the AtlasOS Playbook and run it on a Windows installation to create an optimized ISO
• From inside the VM (OOBE): You can run the AtlasOS Playbook directly during Windows 11’s initial setup phase

Important: ISOs created with AtlasOS are for personal use only. Do not distribute or share these ISOs as they contain Microsoft software. Each user must create their own optimized copy using the official tools and AtlasOS Playbook.

Installation

1. Install packages:

sudo pacman -S virt-manager qemu-full swtpm edk2-ovmf dnsmasq

Note: The virtio-win package is available from the AUR (yay -S virtio-win) or you can download the ISO directly in a later step.

2. Add user to libvirt group:

sudo usermod --append --groups libvirt $(whoami)

Log out and log back in (or reboot) before opening virt-manager.

3. Start and enable libvirtd:

sudo systemctl enable --now libvirtd

4. Configure default network:

sudo virsh net-start default
sudo virsh net-autostart default

Note: If you see “network is already active”, it is already running.

sudo ufw allow in on virbr0 to any port 53 proto udp comment 'VM DNS'
sudo ufw allow in on virbr0 to any port 67 proto udp comment 'VM DHCP'
sudo ufw route allow in on virbr0
sudo ufw route allow out on virbr0

5. Download VirtIO drivers ISO:

# Download the official stable VirtIO drivers ISO (~753 MB)
sudo curl -L -o /var/lib/libvirt/images/virtio-win.iso \
  https://fedorapeople.org/groups/virt/virtio-win/direct-downloads/stable-virtio/virtio-win.iso

# Verify the download (should be ~753 MB)
ls -lh /var/lib/libvirt/images/virtio-win.iso

Let the download finish; it is large.

6. Verify your setup:

# Check if you're in the libvirt group (after logging back in)
groups

# You should see "libvirt" in the output
# If not, log out and back in again

# Test if libvirt works
sudo virsh list --all

7. Prepare Windows ISO:

Download or copy your Windows 11 Enterprise ISO to /var/lib/libvirt/images/:

# If you already downloaded the ISO:
sudo cp ~/Downloads/Enterprise-25H2.iso /var/lib/libvirt/images/

# Or download directly to the correct location:
sudo curl -L -o /var/lib/libvirt/images/Enterprise-25H2.iso [ISO_URL]

Virt-manager can now directly select both ISOs from this directory.

8. (Optional) Create a separate storage pool for VM disks:

By default, virt-manager stores everything in /var/lib/libvirt/images/. If you want VM disks on a separate drive or partition:

1. Create the mount point and mount your drive (e.g. /mnt/vmstore)
2. In virt-manager: Edit → Connection Details → Storage
3. Click + to add a new pool
4. Name: vmstore, Type: dir, Target Path: /mnt/vmstore

This keeps large VM disk images off your root filesystem.

9. Create VM in virt-manager:

• File → New Virtual Machine → Local install media
• Select Windows 11 Enterprise ISO
• Memory: 8192 MB (8 GB), CPUs: 8, Storage: 200 GB (qcow2)
• Check “Customize configuration before install”

10. Configure hardware:

11. Add VirtIO ISO:

• Add Hardware → Storage → CDROM
• Select /var/lib/libvirt/images/virtio-win.iso
• Bus: SATA

Click Begin Installation.

Windows Installation

1. Load VirtIO storage driver:

At “Where do you want to install Windows?”:

• Load driver → Browse → viostor\w11\amd64\ → Next

2. Complete installation

3. Local account:

If “I don’t have internet” is not available:

• Shift+F10 → start ms-cxh:localonly → Enter

4. Install VirtIO guest tools (during OOBE):

Before finishing the OOBE setup, install the VirtIO guest drivers for better performance:

• Press Shift+F10 to open a command prompt
• The VirtIO ISO is mounted as a CD-ROM drive (e.g. D: or E:)
• Run the installer: D:\virtio-win-guest-tools.exe
• After installation finishes, close the command prompt and continue the OOBE

This installs all VirtIO drivers (network, display, balloon, etc.) so Windows runs with optimal performance from the start.

5. SPICE Guest Tools:

Download and install for clipboard/file sharing:

spice-guest-tools-latest.exe (from spice-space.org)

Windows should now run with good performance.

Post-install VM optimization

After Windows is installed and the guest tools are in place, you can fine-tune the VM configuration for better performance. Below is the optimized XML configuration and an explanation of the key settings.

Key configuration choices explained

Full VM XML reference

<domain type="kvm">
  <name>win11</name>
  <uuid>2a2aa4b0-5f6e-4d0e-a422-de3d63b8966f</uuid>
  <title>win11</title>
  <metadata>
    <libosinfo:libosinfo xmlns:libosinfo="http://libosinfo.org/xmlns/libvirt/domain/1.0">
      <libosinfo:os id="http://microsoft.com/win/11"/>
    </libosinfo:libosinfo>
  </metadata>
  <memory unit="KiB">8388608</memory>
  <currentMemory unit="KiB">8388608</currentMemory>
  <vcpu placement="static">8</vcpu>
  <os firmware="efi">
    <type arch="x86_64" machine="pc-q35-10.1">hvm</type>
    <firmware>
      <feature enabled="yes" name="enrolled-keys"/>
      <feature enabled="yes" name="secure-boot"/>
    </firmware>
    <loader readonly="yes" secure="yes" type="pflash" format="qcow2">/usr/share/edk2/ovmf/OVMF_CODE_4M.secboot.qcow2</loader>
    <nvram template="/usr/share/edk2/ovmf/OVMF_VARS_4M.secboot.qcow2" templateFormat="qcow2" format="qcow2">/var/lib/libvirt/qemu/nvram/win11_VARS.qcow2</nvram>
    <boot dev="hd"/>
  </os>
  <features>
    <acpi/>
    <apic/>
    <hyperv mode="custom">
      <relaxed state="on"/>
      <vapic state="on"/>
      <spinlocks state="on" retries="8191"/>
      <vpindex state="on"/>
      <runtime state="on"/>
      <synic state="on"/>
      <stimer state="on"/>
      <frequencies state="on"/>
      <tlbflush state="on"/>
      <ipi state="on"/>
      <avic state="on"/>
    </hyperv>
    <vmport state="off"/>
    <smm state="on"/>
  </features>
  <cpu mode="host-passthrough" check="none" migratable="on">
    <topology sockets="1" dies="1" clusters="1" cores="8" threads="1"/>
  </cpu>
  <clock offset="localtime">
    <timer name="rtc" tickpolicy="catchup"/>
    <timer name="pit" tickpolicy="delay"/>
    <timer name="hpet" present="no"/>
    <timer name="hypervclock" present="yes"/>
  </clock>
  <on_poweroff>destroy</on_poweroff>
  <on_reboot>restart</on_reboot>
  <on_crash>destroy</on_crash>
  <pm>
    <suspend-to-mem enabled="no"/>
    <suspend-to-disk enabled="no"/>
  </pm>
  <devices>
    <emulator>/usr/bin/qemu-system-x86_64</emulator>
    <disk type="file" device="disk">
      <driver name="qemu" type="qcow2" cache="writeback" io="threads" discard="unmap"/>
      <source file="/mnt/vmstore/win11.qcow2"/>
      <target dev="vda" bus="virtio"/>
    </disk>
    <controller type="usb" index="0" model="qemu-xhci" ports="15"/>
    <controller type="pci" index="0" model="pcie-root"/>
    <controller type="virtio-serial" index="0"/>
    <interface type="network">
      <source network="default"/>
      <model type="virtio"/>
    </interface>
    <serial type="pty">
      <target type="isa-serial" port="0">
        <model name="isa-serial"/>
      </target>
    </serial>
    <console type="pty">
      <target type="serial" port="0"/>
    </console>
    <channel type="spicevmc">
      <target type="virtio" name="com.redhat.spice.0"/>
    </channel>
    <channel type="unix">
      <target type="virtio" name="org.qemu.guest_agent.0"/>
    </channel>
    <input type="keyboard" bus="virtio"/>
    <input type="tablet" bus="virtio"/>
    <input type="mouse" bus="ps2"/>
    <input type="keyboard" bus="ps2"/>
    <tpm model="tpm-crb">
      <backend type="emulator" version="2.0"/>
    </tpm>
    <graphics type="spice">
      <listen type="none"/>
      <image compression="off"/>
      <streaming mode="filter"/>
      <gl enable="yes" rendernode="/dev/dri/by-path/pci-0000:66:00.0-render"/>
    </graphics>
    <sound model="ich9"/>
    <audio id="1" type="spice"/>
    <video>
      <model type="virtio" heads="1" primary="yes">
        <acceleration accel3d="yes"/>
      </model>
    </video>
    <redirdev bus="usb" type="spicevmc"/>
    <redirdev bus="usb" type="spicevmc"/>
    <watchdog model="itco" action="reset"/>
    <memballoon model="virtio"/>
  </devices>
</domain>

Guest tools installation (inside Windows)

For the best VM performance, two sets of guest tools must be installed inside the Windows guest:

VirtIO Guest Tools (from the VirtIO ISO):

• Installs paravirtualized drivers for disk, network, display, memory balloon, serial, and input
• Also installs the QEMU Guest Agent for host-guest communication
• Without these drivers, disk and network performance will be significantly worse

SPICE Guest Tools (from spice-space.org):

• Enables clipboard sharing between host and guest
• Enables drag-and-drop file transfer
• Enables dynamic display resolution (guest resolution follows the SPICE window size)
• Installs the SPICE WebDAV agent for folder sharing

Both are essential for a smooth VM experience.

Snapshots

# Create snapshot (VM must be off)
virsh shutdown win11
qemu-img snapshot -c snapshot-name /mnt/vmstore/win11.qcow2

# List
qemu-img snapshot -l /mnt/vmstore/win11.qcow2

# Revert
qemu-img snapshot -a snapshot-name /mnt/vmstore/win11.qcow2