Virtio drivers from Red Hat for their RHEV product

https://rhn.redhat.com/errata/RHEA-2009-1624.html

A new package, virtio-win, which adds signed, para-virtalized Windows
drivers for fully-virtualized 32-bit and 64-bit Windows guests is now
available.

Para-virtualized drivers are virtualization-aware drivers used by fully
virtualized guests running on Red Hat Enterprise Linux. Fully-virtualized
guests using the para-virtualized drivers gain significantly better I/O
performance than fully-virtualized guests running without the drivers.

This new package provides signed, para-virtualized network drivers for the
following guest operating systems:

Windows XP, 32-bit
Windows Server 2003, 32-bit
Windows Server 2003, 64-bit
Windows Server 2008, 32-bit
Windows Server 2008, 64-bit
Windows Server 2008 R2

This new package also provides signed, para-virtualized disk (block)
drivers for the following guest operating systems:

Windows Server 2003, 32-bit
Windows Server 2003, 64-bit
Windows Server 2008, 32-bit
Windows Server 2008, 64-bit
Windows Server 2008 R2

These drivers are provided as four Windows Installer (.msi) files on a
mountable .iso file installed to /usr/share/virtio-win/virtio-win-1.0.0.iso
on the host machine. (BZ#529617)

Note: when the disk drivers for the 32-bit version of Windows Server 2008
are installed using RHEV-Block.msi, the drivers for 32-bit Windows Server
2003 may, incorrectly, be installed. The recommended way to install the
32-bit Windows Server 2008 disk drivers is to attach the included virtual
floppy disk file, /usr/share/virtio-win/virtio-drivers-1.0.0.vfd, to the
guest and install from there.

All users running fully-virtualized instances of Windows on Red Hat
Enterprise Linux-based KVM hosts should install these new packages which
significantly improve I/O performance.