4 Guest Additions
•OpenGL on Linux requires kernel 2.6.27 and higher as well as X.org server
version 1.5 and higher. Ubuntu 8.10 and Fedora 10 have been tested and
confirmed as working.
•OpenGL on Solaris guests requires X.org server version 1.5 and higher.
2. The Guest Additions must be installed.
Note: For Direct 3D acceleration to work in a Windows Guest, VirtualBox
needs to replace Windows system files in the virtual machine. As a result, the
Guest Additions installation program offers Direct 3D acceleration as an op-
tionthat must be explicitly enabled.Also, youmust install the Guest Additions
in “Safe Mode”; see chapter 13,Known limitations, page 213 for details.
3. Because 3D support is still experimental at this time, it is disabled by default
and must be manually enabled in the VM settings (see chapter 3.7.1,General
settings, page 46).
Technically, VirtualBoximplements this by installing an additional hardware 3D
driver inside your guest when the Guest Additions are installed. This driver acts as
a hardware 3D driver and reports to the guest operating system that the (virtual)
hardware is capable of 3D hardware acceleration. When an application in the guest
then requests hardware acceleration through the OpenGL or Direct3D programming
interfaces, these are sent to the host through a special communication tunnel imple-
mented by VirtualBox, and then the host performs the requested 3D operation via the
host’s programming interfaces.
4.9 Guest properties
Starting with version 2.1, VirtualBox allows for requesting certain properties from a
running guest, provided that the VirtualBox Guest Additions are installed and the VM
is running. This is good for two things:
1. A number of predefined VM characteristics are automatically maintained by
VirtualBox and can be retrieved on the host, e.g. to monitor VM performance
and statistics.
2. In addition, arbitrary string data can be exchanged between guest and host, and
in both directions.
To accomplish this, VirtualBox establishes a private communication channel be-
tween the VirtualBox Guest Additions and the host, and software on both sides can
use this channel to exchange string data for arbitrary purposes. Guest properties are
simply string keys to which a value is attached. They can be set (written to) by either
the host and the guest, and they can also be read from both sides.
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