RHBA-2010:0264 - Bug Fix Advisory

Topic

Updated qspice packages that fix various bugs are now available.

Description

The Simple Protocol for Independent Computing Environments (SPICE), a
remote display protocolis used in Red Hat Enterprise Linux for viewing
virtualized guests running on the KVM hypervisor or on Red Hat Enterprise
Virtualization Hypervisors.

The updated packages fix the following bugs:

• Previously, if some sites sent two video frame pixmaps, the SPICE

heuristic failed to detect the video stream and caused a dramatic increase
in CPU use and network traffic. With this update, the dual-pixmap video
streams is detected, video playback occurs as expected and CPU use and
network traffic no longer spike. (BZ#518193)

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

external factors affected the data stream, thi 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#518388)

• the SPICE server previously sent a new client connections an

uncompressed initial screen image. In low bandwidth conditions this
resulted in a long period of apparent inactivity, with the client
presenting an unusable black screen. The SPICE server now compresses the
initial screen image, greatly reducing initialization time. (BZ#521488)

• if configured with SSL, previously a SPICE client would open SSL with

DEFLATE compression and the server would accept the compression, resulting
in a poor display. Currently, if the client offers SSL compression, the
compression is not accepted by the server. (BZ#482111)

• The video compression algorithm can start when the guest is

accessing text instead of video causing the text to be blurry. The SPICE
server now has an improved heuristic for distinguishing between videos and
textual streams. (BZ#493375)

• VM run on loaded host crashed when SPICE session opened from RHEV Manager

Local-Host [trap divide error 0]. (BZ#525055)

• Sometimes a client was timed out if the server was overloaded or due to

low bandwidth. Client time-out has been increased to 15 seconds to prevent
this.(BZ#526458)

• Qemu crashed when OpenOffice 3.1.1 launched .odp files. (BZ#545862)
• SPICE client files have been removed from qspice package. (BZ#549532)
• Destination server authentication during migration process is now

supported. The SPICE server sends destination server identity to the client
which uses it to authenticate the server.(BZ#549673)

• Previous qemu and SPICE server crashes were caused by wrong access to

ring items in the code. These have since been resolved.(BZ#551580)and
(BZ#559207)

• A video streaming issue caused display of an unclean Welcome button on

log-out on a Windows 7 guest. A lower limit to streamable images prevents
streaming of images that are probably textual.(BZ#558270)

• In Windows media player 12 full screen mode small videos are scaled

directly and sent to the client. SPICE server identified the scaled images
as "artificial" and did not stream them. A more permissive heuristic now
enables these to be streamed.

Users requiring remote display capabilities for KVM hypervisors are advised
to upgrade to these updated qspice packages which resolve the above 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 Workstation 5 x86_64

Fixes

• BZ - 482111 - SPICE - if configured with SSL, it'll open SSL with DEFLATE compression
• BZ - 518193 - Error in detecting the video stream on some web sites (for example: CNN site)
• BZ - 518388 - Video frames drop in low network bandwidth condition
• BZ - 521488 - Long client session initialization process in low network bandwidth condition
• BZ - 526458 - Sometimes client get disconnected on time out from server. Time out must be increased.
• BZ - 549532 - Remove spice client files from qspice package
• BZ - 549673 - Sever authentication need to be added to migration process
• BZ - 562744 - windows media player 12 (win 7) guest - videos unrecognized in full screen mode

CVEs

(none)

References

(none)