[Spice-devel] Fwd: Spice/LTSP combo

[Uri Lublin]

On 06/16/2013 11:39 AM, Ivan Krutskikh wrote:
> Hi

Hi Ivan,

>
> I like spice protocol a lot and want to integrate it into Kiwi/LTSP 
> project in order to have hybrid terminal server/ VDI solution with 
> diskless client machines.
> But there are some things, that I need to clear out first:
>
> 1) In order to create an LTSP screen session, I need to start spice 
> client (spicec or spicy) in full screen mode with security creditials, 
> spice adress and auto usb redirection on. I can do most of it with 
> spicec command line options, but it seams to lack support for usb 
> redirection. How can I do the same with spicy?

You better use remote-viewer as your spice client.
It accepts properties setting via the "controller" or if you prefer,
It can read properties from a configuration file (e.g. 
connection_params.vv).


>
> 2) Excuse me if f.a.q, but I need to make usb devices redirection 
> possible for non-root users. I suppose, that should be done with udev 
> rule, but no expert in hardware security issues.

This can be done with changing a PolicyKit rule.

See 
http://lists.freedesktop.org/archives/spice-devel/2012-February/007198.html
that point to http://hansdegoede.livejournal.com/11936.html


>
> 3) Sometime I get video artefacts from when viewing IP cameras on a 
> virtual machine. Example image attached. I believe, this happens due 
> to the video detection and mjpeg compression in spice ( h264 ip cam 
> --> player decoding --> raw video --> spice stream detection and mjpeg 
> encoding --> client video decoding --> raw video with artefacts). So 
> the reasonable step would be to disable video stream compression for 
> local network in libvirt xml file. But there are 4 parameters: image 
> compression, jpeg compression, zlib compression, playback compression- 
> I don't know which one to disable and how. Setting all to "off" and 
> "never" seams to resolv the issue, but leads to crappy wan performance.

The  "streaming-video=off" setting of qemu-kvm command line "-spice" 
option - can be used to disable video streaming.

For more information about -spice settings -- man qemu-kvm -- or man 
qemu -- http://linux.die.net/man/1/qemu-kvm
and look for "-spice "

(taken from http://libvirt.org/formatdomain.html#elementsGraphics)
To disable video streaming in a libvirt xml file  add
   <streaming mode='never'>  to <graphics .. spice>


Uri.