3.2. Installing the para-virtualized drivers

This section details the process for installing the para-virtualized drivers on newly created Microsoft Windows guests using virsh or virt-manager.

You can access the Microsoft Windows para-virtualized drivers installer from your guest using either:

hosting the files on a network accessible to the guest, or
by creating a virtualized CD-ROM device on the guest of the installation disk .iso file.

This guide describes installation from the para-virtualized installer disk as a virtualized CD-ROM device.

Download the para-virtualized drivers package with yum. The package names in the list below are to assist you with choosing the right package for your guest.

Para-virtualized drivers package names

xenpv-win: The standard driver package.
xenpv-win-debug: The package for debugging the drivers.

The debug packages are used for debugging the para-virtualized driver inside of the windows guests. These drivers provide users with more verbose reporting, checking for erroneous conditions and debug information for use within a Windows kernel debugger. Using the debug packages outside the debugging environment might lead to an unstable guest.

To install the .iso file containing the drivers, use yum on a host with the Virtualization channel in RHN enabled:

# yum install xenpv-win

This extracts the packaged files to the /usr/share/xenpv-win directory. The Bash output below shows the contents of a /usr/share/xenpv-win directory with both normal and debugging packages installed. Note the symbolic links(denoted by the -> symbol) linking to the newest version of the para-virtualized drivers.

$ ls -al /usr/share/xenpv-win
total 13472
drwxr-xr-x   2 root root    4096 Jul 14 17:29 .
drwxr-xr-x 214 root root    4096 Jul 14 17:29 ..
-rw-r--r--   1 root root 4325952 Jul 11 14:58 xenpv-win-1.1.0.iso
-rw-r--r--   1 root root 4422208 Jul 11 14:58 xenpv-win-debug-1.1.0.iso
lrwxrwxrwx   1 root root      32 Jul 14 17:29 xenpv-win-debug.iso -> xenpv-win-debug-1.1.0.iso
lrwxrwxrwx   1 root root      26 Jul 14 17:29 xenpv-win.iso -> xenpv-win-1.1.0.iso

The .iso files in the /usr/share/xenpv-win directory should be mounted as virtual CD-ROM devices for the Windows guests in order to install the drivers. To create the virtualized CD-ROM device you must choose to use either virt-manager(graphical) or virsh(command line).

Mounting the image with virt-manager

Follow Procedure 3.1, “Using virt-manager to mount a CD-ROM image for a Windows guest” to add a CD-ROM image with virt-manager.

Procedure 3.1. Using `virt-manager` to mount a CD-ROM image for a Windows guest

Open virt-manager, select your virtualized guest from the list of virtual machines and press the Details button.
Click the Add button in the Details panel.
This opens a wizard for adding the new device. Select Storage device from the drop down menu, then click Forward.
Choose the Simple File option and set the file location of the para-virtualized drivers .iso file. The location of the .iso files is /usr/share/xenpv-win if you used yum to install the para-virtualized driver packages.
If the drivers are stored physical CD, use the Normal Disk Partition option.
Set the Device type to IDE cdrom and click Forward to proceed.
The disk has been assigned and is available for the guest once the guest is started. Click Finish to close the wizard or back if you made a mistake.

Mounting the image with virsh

To mount .iso images with virsh guests must be either active(on) or inactive(off) state. For inactive guests refer to Appendix A, Using virsh to mount a CD-ROM image on an inactive domain. For mounting the CD-ROM image on an active guest with virsh, follow Procedure 3.2, “Mounting the driver installation CD-ROM image with virsh on an active guest”.

Procedure 3.2. Mounting the driver installation CD-ROM image with `virsh` on an active guest

Determine the required parameters, including:
1. An active domain. In the example the domain is called w2k3_32.
2. An unallocated block device label. The example in the next step uses hdc, if hdc is already allocated choose the next unallocated letter for example hdd. You can verify which drive labels are in use by reading the configuration file generated with the virsh dumpxml. For example, if your guest's name is w2k3_32, the command virsh dumpxml w2k3_32 > w2k3_32guest.xml will generate a configuration file called w2k3_32guest.xml in the current directory.
3. The correct driver package. Assuming debugging symbols are not necessary, the xenpv-win.iso from the xenpv-win package is needed.

Use the virsh command with the parameters modified for your guest.

# virsh attach-disk w2k3_32 /usr/share/xenpv-win/xenpv-win.iso hdc --driver file --type cdrom --mode readonly

Warning

The above procedure only works on active domains. Refer to Appendix A, Using virsh to mount a CD-ROM image on an inactive domain for inactive domains.

Para-virtualized drivers executable file names

Executable file name	Description
`xenpv-win.exe`	The para-virtualized driver package for 32-bit and 64-bit Microsoft Windows installations. This covers most installations.
`xenpv-win-debug.exe`	The para-virtualized driver debugging package for 32-bit and 64-bit Microsoft Windows installations.

Procedure 3.3. Installing the para-virtualized drivers on the Windows® guest

The installer may start automatically if you added the virtualized CD-ROM to an active guest. If this occurs skip this step and continue from step 2. Otherwise, double clicking the CD drive (D: in the example below) will start the installer.
If Autorun is disabled, start the installer by double clicking the .exe file on the CD.
Once the file is open, the Welcome screen appears. Select Next to proceed.
You are now prompted to select the parts of the driver package that you want to install.
The default installation includes the network driver, disk driver, source code and documentation (in HTML and PDF formats).
The Start drivers on reboot option, if unchecked, will install the driver binaries without starting them. Instructions for starting the drivers later can be found in Section 4.4, “Disabling the drivers”.
Once you have made your selection, click Next to continue.
In the next step, you can optionally point the installation program to the desired folder for the source code, documentation and auxiliary files for the drivers.

Then press Install to complete the installation.
Note
It is strongly suggested to install the para-virtualized drivers on a non-paravirtualized drive, typically the C: drive. While this is not necessary for proper operation of the drivers, other choices may cause problems if you later wish to uninstall or temporarily disable the drivers.
The unsigned driver warning (The software you are installing has not passed Windows Logo Testing) dialog box pops up. Select Continue Anyway to install drivers. This dialog box will appear three times, and may appear again after rebooting the machine.

Note
Future releases of Red Hat Para-virtualized Driver for Microsoft Windows will be digitally signed by Windows Hardware Quality Labs(WHQL). Once certified the warning will not appear.
Click Finish to complete the installation.
Complete all "Install new hardware wizard" windows which appear.
Disconnected para-virtualized network adapters
After this step, para-virtualized network adapters will be installed in the system. However, Windows will show the adapters as "Disconnected" until the next reboot. This is expected, since the para-virtualized adapters would conflict with the emulated adapters.
Reboot the guest.