Re: Help needed running an X11 environment inside a DomU (Re: [Xen-users]Creating a paravirtualized guest with Xen 3.4.1 and Centos 5.3 (64bit))

[Martin Troester <TroyMcClure@xxxxxx>]

Hi Grant, Fajar,

> > Perhaps something like vnc/xrdp/NX would be more suitable.
> My thoughts exactly. I've never bothered with X in xen because NX works
> great. Why have a local server on a Virtual Machine? I think that's what
> KVM/VirtualBox are for. I'm sure everyones application are different though.
Well, the idea is to have an image that runs on bare metal, in HVM and 
(now) in a PV environment. On all systems I want to reconnect to my 
desktop, and on the physical hardware I want the physical display to be 
exported (not a virtual, additional display). Thus on the physical 
installation I export the X server via x11vnc for both local and remote 
operation on the very same desktop. That works fine as well in HVM (as 
it comes with its own emulated graphics adapter), but not so well in the 
framebuffer setup coming with PV - until now the resoltion stays limited 
to 800x600, which seems to be the native virtual fb resolution. This 
setup may sound strange, but as I said, it worked so far ;-)
However, I now got it (almost) running with the fb device, using the 
descriptions I found in:
http://lists.xensource.com/archives/html/xen-devel/2008-02/msg01036.html
and:
http://lists.xensource.com/archives/html/xen-devel/2008-03/msg00398.html

In my words, I had to add the following line to the kernel parameters 
passed via the extra keyword in the xen config file:
extra="xenfb.videomem=32,1024 "
This line configures the xenfb device with 32MB of Video RAM and a 
resolution of 1024x768 (as far as I understand, I did not find a lot 
more docu than this).
The following config works as xorg.conf inside the VM (based on the mail 
threads mentioned above):
Section "Monitor"
   HorizSync 30-65
   Identifier "Monitor[0]"
   ModelName "XEN PV"
   VendorName "XEN"
   VertRefresh 43-75
   UseModes "Modes[0]"
EndSection

Section "Modes"
   Identifier "Modes[0]"]
   Modeline "1024x768" 79.52 1024 1080 1192 1360 768 769 772 801
EndSection

Section "Device"
   Identifier "Device[0]".
   Driver "fbdev"
   Option "fbdev" "/dev/fb0"
EndSection

Section "Screen"
   SubSection "Display"
     Depth 24
     Modes "1024x768"
     Virtual 1024 768
   EndSubSection
   Device "Device[0]"
   Identifier "Screen[0]"
   Monitor "Monitor[0]"
EndSection

Section "ServerLayout"
   Identifier "Default Layout"
   Screen "Screen[0]"
   InputDevice "Mouse1" "CorePointer"
   InputDevice "Mouse2" "SendCoreEvents"
   InputDevice "Keyboard_us" "CoreKeyboard"
EndSection

Section "InputDevice"
        Identifier "Keyboard_us"
        Driver "keyboard"
        Option "XkbLayout" "us"
        Option "XkbModel" "pc104"
EndSection

Section "InputDevice"
    Identifier  "Mouse1"
    Driver      "mouse"
    Option "Protocol"    "PS/2"
    Option "Device"      "/dev/input/mouse0"
EndSection

Section "InputDevice"
    Identifier  "Mouse2"
    Driver      "mouse"
    Option      "Protocol"      "IMPS/2"
    Option      "Device"        "/dev/input/mice"
    Option      "ZAxisMapping"   "4 5"
    Option      "Emulate3Buttons" "no"
EndSection

Well, that's almost it - I seemed to be lucky so far not to have to work 
with mode lines...Those come from the posts mentioned above, and I now 
get a full 1024x768 desktop exported via x11vnc. Unfortunately, some 
lines of the virtual desktop are showing strange colors and seem screwed 
up. I thought decreasing the color depth to 16bit might do the trick, 
but with that changed, the resolution reduces to 800x600 - no idea why, 
but I blame the mode line on this... Any ideas anybody?
Well, that's it for tonight. I understand this is a more or less exotic 
setup, but maybe this helps somebody running into the same issue.
Regards,
Martin

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users