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Installing Virtio Drivers In Windows On KVM

3rd July 2018

Virtio drivers are paravirtualized device drivers for KVM virtual machines.

Paravirtualized drivers enhance the performance of machines, decreasing I/O latency and increasing throughput to near bare-metal levels.

It is recommended to use the paravirtualized drivers for fully virtualized machines.

Most Linux distributions include the virtio drivers as standard. This guide explains how to install them in Windows.

This guide was written for Zetastack users but applies to any Windows guest VM running on a KVM host.

This includes Nutanix, Red Hat Virtualization (RHEV), Proxmox VE, oVirt and OpenStack.

If your device manager looks like this, then this guide will help you.

Download ISO

We recommend the stable release, the same as what is shipped with Red Hat Enterprise Linux.

This is the link to download:

Download and add the ISO to your virtualization platform.

In Zetastack this is done in Settings Import.

Machine Configuration

Edit the machine configuration and set these:

• Disk bus: Virtio SCSI pass-through controller
• NIC model: Virtio Ethernet
• Video model: QXL
• Video RAM: 32MB

Attach ISO

This bit depends on whether you are installing a new Windows VM or you already have an existing Windows VM.

If you are installing a new Windows VM, set the ISO to be the 2nd CD-ROM drive leaving the Windows install ISO as the 1st CD-ROM drive.

Begin Install

If you are not installing a new Windows VM, you can skip this section.

Storage Driver

At the disk detection stage, the Windows installer cannot detect any disks for installation.

This is expected behaviour, since the virtio drivers have not been loaded yet and are not included by Microsoft in the installation media.

Click «Load driver» and select «CD Drive (E:) virtio-win-0.1.1»

The driver required is the «VirtIO SCSI pass-through controller» located at:

For other editions of Windows, the driver will be located in the relevant directory on the ISO.

Select the driver and click «Next».

The driver is loaded and the and the disk is now detected.

Select the disk for installation and click «Next».

Post Install

Once the installation is complete and the VM has booted, the next steps are to install the guest agent and resolve any missing drivers.

Guest Agent

It is essential the guest agent is installed.

The guest agent is used by the hypervisor to communicate directly with the VM.

The guest agent is required for clean VM shutdown and to enable live snapshots of the VM images.

On the task bar click «File Explorer».

Select «This PC» then double click «CD Drive (E:) virtio-win-0.1.1».

Open the «guest-agent» folder.

Right click the «qemu-ga-x64» file and select «Install».

The QEMU guest agent will now install.

Once installed the VM must be completely shutdown before the agent can run.

When the VM is started again, the guest agent service will automatically start.

Device Manager

In Device Manager we can see the following unconfigured devices.

This table lists the devices and the drivers required.

Device	Driver
Storage controller	Virtio SCSI pass-through controller (already installed)
Ethernet controller	Virtio Ethernet adapter
PCI device	Virtio balloon driver
PCI input device	Virtio input driver
PCI simple communications controller	Virtio serial driver
Display adapter	QXL video driver
HID button over interrupt driver	Generic bus

The procedure is simple but repetitive.

Generic Bus

This is a Microsoft bug which is easily resolved.

Right click on «HID Button over Interrupt Driver» and select «Update Driver Software. «

Select «Browse my computer for driver software».

Select «Let me pick from a list of device drivers on my computer».

Select the model «Generic Bus».

This resolves the bug, and removes the driver warning.

Virtio Ethernet Adapter

This is a high speed driver capable of 10GbE and better.

Right click on «Ethernet Controller» and select «Update Driver Software. «.

Select «Browse my computer for driver software».

Select «CD Drive (E:) virtio-win-0.1.1» and click OK.

Device Manager will automatically find the correct driver. The path to the driver does not need to be specified.

At the prompt click «Install».

The driver is installed.

The device description has now changed in Device Manager.

Virtio Balloon Driver

The balloon driver allows the memory in the VM to be changed dynamically.

Right click on «PCI Device» and select «Update Driver Software. «.

Follow the same steps for the Ethernet adapter above to complete the driver installation.

Virtio Input Driver

This provides accurate mouse tracking within the console.

Right click on «PCI Input Device» and select «Update Driver Software. «.

Follow the same steps for the Ethernet adapter above to complete the driver installation.

Virtio Serial Driver

This is a virtual serial port for communication between the hypervisor and the VM.

Right click on «PCI Simple Communications Controller» and select «Update Driver Software. «.

Follow the same steps for the Ethernet adapter above to complete the driver installation.

QXL Video Driver

This is a video driver that improves performance and allows for higher resolutions.

It also provides a seamless cursor when using the console to manage the VM.

Right click on «Microsoft Basic Display Adapter» and select «Update Driver Software. «.

Follow the same steps for the Ethernet adapter above to complete the driver installation.

Cursor Tweak

When using the QXL driver, the mouse cursor needs to be tweaked.

This will provide a seamless cursor in web based VM consoles.

On the start menu click «Settings».

Click «Mouse & touchpad».

Click «Additional mouse options».

In the Pointers tab, enable «Enable pointer shadow» and click OK to update.

This allows the use of black and extra large cursors.

Windows 10 guest best practices

Contents

Introduction

This is a set of best practices to follow when installing a Windows 10 guest on a Proxmox VE server 6.x. Right now it’s a work in progress.

Install

Prepare

To obtain a good level of performance, we will install the Windows VirtIO Drivers during the Windows installation.

• Create a new VM, select «Microsoft Windows 10/2016/2019» as Guest OS and enable the «Qemu Agent» in the System tab. Continue and mount your Windows 10 ISO in the CDROM drive
• For your virtual hard disk select «SCSI» as bus with «VirtIO SCSI» as controller. Set «Write back» as cache option for best performance (the «No cache» default is safer, but slower) and tick «Discard» to optimally use disk space (TRIM).
• Configure your memory settings as needed, continue and set «VirtIO (paravirtualized)» as network device, finish your VM creation.
• For the VirtIO drivers, upload the driver ISO (use the stable VirtIO ISO, download it from here) to your storage, create a new CDROM drive (use «Add -> CD/DVD drive» in the hardware tab) with Bus «IDE» and number 3. Load the Virtio Drivers ISO in the new virtual CDROM drive.
• Now your ready to start the VM, just follow the Windows installer.

Launch Windows install

• After starting your VM launch the noVNC console
• Follow the installer steps until you reach the installation type selection where you need to select «Custom (advanced)»
• Now click «Load driver» to install the VirtIO drivers for hard disk and the network.
  • Hard disk: Browse to the CD drive where you mounted the VirtIO driver and select folder «vioscsi\w10\amd64» and confirm. Select the «Red Hat VirtIO SCSI pass-through controller» and click next to install it. Now you should see your drive.
  • Network: Repeat the steps from above (click again «Load driver», etc.) and select the folder «NetKVM\w10\amd64», confirm it and select «Redhat VirtIO Ethernet Adapter» and click next.
  • Memory Ballooning: Again, repeat the steps but this time select the «Balloon\w10\amd64» folder, then the «VirtIO Balloon Driver» and install it by clicking next. With these three drivers you should be good covered to run a fast virtualized Windows 10 system.
• Choose the drive and continue the Windows installer steps.

HINT: There is a video showing the process for a Windows Server 2016 installation which is the same as for Windows 10.

Install Guest Agent and Services

Guest Agent

If you enabled the Qemu Agent option for the VM the mouse pointer will probably be off after the first boot.

To remedy this install the «Qemu Guest Agent». The installer is located on the driver CD under guest-agent\qemu-ga-x86_64.msi.

Drivers and Services

The easiest way to install missing drivers and services is to use the provided MSI installer. It is available on the driver CD since version «virtio-win-0.1.173-2».

Run the «virtio-win-gt-x64.msi» file located directly on the CD. If you do not plan to use SPICE you can deselect the «Qxl» and «Spice» features. Restart the VM after the installer is done.

After all this the RAM usage and IP configuration should be shown correctly in the summary page of the VM.

For more information and configuration about ballooning, see Dynamic Memory Management

Check for missing drivers

Go to the Device Manager to see if there are any drivers missing. For any unknown device:

• Right click an select «Update driver».
• Select «Browse my computer for driver software».
• Select the Driver CD. Make sure that «Include subfolders» is checked.
• Once a driver has been found you might be prompted with a security warning asking if you «Would like to install this device software». Click «Install».

Further information

Disk-Image Format: raw vs qcow2

Raw file format provides slightly better performance while qcow2 offers advanced features such as copy on write and Live_Snapshots. Since V2.3, qcow2 is the default format.

VirtIO drivers

Make it really easy: Build your ISO with drivers already included: Windows guests — build ISOs including VirtIO drivers