RHBA-2009:1489 - Bug Fix Advisory

Topic

Updated qspice packages that fix several bugs are now available.

Description

The Simple Protocol for Independent Computing Environments (SPICE) is a
remote display protocol designed for virtual environments. SPICE users can
view a virtualized desktop or server from the local system or any system
with network access to the server. SPICE is available for a variety of
machine architectures and operating systems. SPICE is used in Red Hat
Enterprise Linux for viewing virtualized guests running on the KVM
hypervisor or on Red Hat Enterprise Virtualization Hypervisors.

These updated packages fix the following bugs:

• the SPICE server uses a heuristic method for detecting video streams.

Some sites, however, send two video frame pixmaps: the actual size of the
frame and a variant that measures from the top-left of the web-page
presenting the frame to the bottom-right of the video frame. Receiving two
video pixmaps caused the SPICE heuristic to fail to detect the video
stream. This failure also caused a dramatic increase in CPU use and network
traffic. With this update, the heuristic detects dual-pixmap video streams
accurately; video playback occurs as expected and CPU use and network
traffic no longer spike. (BZ#521791)

• previously the SPICE server used a fixed bit-rate for video streams. If

external factors affected the data stream, this fixed bit-rate resulted in
dropped frames and low quality playback. With this update, the SPICE server
no longer uses a hard-coded bit-rate; instead it can choose a bit-rate that
reflects current network conditions, improving video playback in
low-bandwidth conditions. (BZ#521792)

• on new client connections the SPICE server previously sent the client an

uncompressed initial screen image. In low bandwidth conditions this
resulted in a long period of apparent inactivity, with the client
presenting an unsuable black screen. The SPICE server now compresses the
initial screen image, greatly reducing initialization time. (BZ#522049)

Users requiring remote display capabilities for KVM hypervisors are advised
to upgrade to these updated qspice packages, which resolve these issues.

Solution

Before applying this update, make sure that all previously-released
errata relevant to your system have been applied.

This update is available via Red Hat Network. Details on how to use
the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.4 x86_64
• Red Hat Enterprise Linux Workstation 5 x86_64

Fixes

• BZ - 521791 - Error in detecting the video stream on some web sites (for example: CNN site)
• BZ - 521792 - Video frames drop in low network bandwidth condition
• BZ - 522049 - Long client session initialization process in low network bandwidth condition
• BZ - 525543 - QSpice :VM run on loaded host crashed when spice session opened from RHEVManager Local-Host[trap divide error 0] .
• BZ - 527723 - SPICE - if configured with SSL, it'll open SSL with DEFLATE compression

CVEs

(none)

References

(none)