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Paul Schulze

2008-Jun-15 12:49 UTC

[Xen-users] PV DomU VNC screen black and Xorg error

Hey everyone,

I tried to get framebuffer VNC working in my PV DomU because I need  
graphical console access, but I keep getting a completely black  
screen in the VNC viewer (so VNC is active, qemu-dm is running) and  
this error message from Xorg:
---
(EE) FBDEV(0): FBIOPUT_VSCREENINFO succeeded but modified mode
(EE) FBDEV(0): mode initialization failed

Fatal server error:
AddScreen/ScreenInit failed for driver 0
---

The system is an AMD Athlon X2 with 4GB RAM, running Hardy and kernel  
2.6.24-18-xen (xen framebuffer and keyboard support built in) from  
the Ubuntu repository. The DomU is running Hardy with the same kernel  
as well and was created using xen-tools. I changed this in the config  
file:
---
vfb = [ "type=vnc,vncunused=1,vnclisten=xx.xx.xx.xx,vncpasswd=xxxxx" ]
extra = ''2 console=xvc console=tty''
---

The /etc/X11/xorg.conf looks like this:
---
Section "InputDevice"
         Identifier      "Generic Keyboard"
         Driver          "kbd"
         Option          "XkbRules"      "xorg"
         Option          "XkbModel"      "pc105"
         Option          "XkbLayout"     "de"
EndSection

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

Section "Device"
         Identifier      "Xen Framebuffer Video Device"
         Driver          "fbdev"
         Option          "fbdev"                 "/dev/fb0"
EndSection

Section "Monitor"
        Identifier      "No Monitor"
EndSection

Section "Screen"
         Identifier      "Default Screen"
         Monitor         "No Monitor"
         Device          "Xen Framebuffer Video Device"
EndSection

Section "ServerLayout"
         Identifier      "Default Layout"
         Screen          "Default Screen"
         InputDevice     "Xen Mouse"
EndSection
---

Can someone please tell me what I am doing wrong or if there is a  
better way to get X11 working on a PV guest.

Thanks,


Paul.

--
Paul Schulze
avlex@gmx.net
Public Key: http://solaris-net.dyndns.org/keys/key_avlex.asc

"Making mistakes is human,
but to really fuck things up you need Computers"



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Paul Schulze

2008-Jun-15 12:50 UTC

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[Xen-users] PV DomU VNC screen black and Xorg error

Hey everyone,

I tried to get framebuffer VNC working in my PV DomU because I need  
graphical console access, but I keep getting a completely black  
screen in the VNC viewer (so VNC is active, qemu-dm is running) and  
this error message from Xorg:
---
(EE) FBDEV(0): FBIOPUT_VSCREENINFO succeeded but modified mode
(EE) FBDEV(0): mode initialization failed

Fatal server error:
AddScreen/ScreenInit failed for driver 0
---

The system is an AMD Athlon X2 with 4GB RAM, running Hardy and kernel  
2.6.24-18-xen (xen framebuffer and keyboard support built in) from  
the Ubuntu repository. The DomU is running Hardy with the same kernel  
as well and was created using xen-tools. I changed this in the config  
file:
---
vfb = [ "type=vnc,vncunused=1,vnclisten=xx.xx.xx.xx,vncpasswd=xxxxx" ]
extra = ''2 console=xvc console=tty''
---

The /etc/X11/xorg.conf looks like this:
---
Section "InputDevice"
         Identifier      "Generic Keyboard"
         Driver          "kbd"
         Option          "XkbRules"      "xorg"
         Option          "XkbModel"      "pc105"
         Option          "XkbLayout"     "de"
EndSection

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

Section "Device"
         Identifier      "Xen Framebuffer Video Device"
         Driver          "fbdev"
         Option          "fbdev"                 "/dev/fb0"
EndSection

Section "Monitor"
        Identifier      "No Monitor"
EndSection

Section "Screen"
         Identifier      "Default Screen"
         Monitor         "No Monitor"
         Device          "Xen Framebuffer Video Device"
EndSection

Section "ServerLayout"
         Identifier      "Default Layout"
         Screen          "Default Screen"
         InputDevice     "Xen Mouse"
EndSection
---

Can someone please tell me what I am doing wrong or if there is a  
better way to get X11 working on a PV guest.

Thanks,


Paul.

--
Paul Schulze
avlex@gmx.net
Public Key: http://solaris-net.dyndns.org/keys/key_avlex.asc

"Making mistakes is human,
but to really fuck things up you need Computers"



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Xen-users mailing list
Xen-users@lists.xensource.com
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jim burns

2008-Jun-15 14:30 UTC

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Re: [Xen-users] PV DomU VNC screen black and Xorg error

On Sunday June 15 2008 08:50:13 am Paul Schulze wrote:> The /etc/X11/xorg.conf looks like this:
> ---
> Section "InputDevice"
>          Identifier      "Generic Keyboard"
>          Driver          "kbd"
>          Option          "XkbRules"      "xorg"
>          Option          "XkbModel"      "pc105"
>          Option          "XkbLayout"     "de"
> EndSection
>
> Section "InputDevice"
>          Identifier      "Xen Mouse"
>          Driver          "mouse"
>          Option          "Protocol"      "PS/2"
>          Option          "Device"      
 "/dev/input/mouse0"
> EndSection
>
> Section "Device"
>          Identifier      "Xen Framebuffer Video Device"
>          Driver          "fbdev"
>          Option          "fbdev"                
"/dev/fb0"
> EndSection
>
> Section "Monitor"
>         Identifier      "No Monitor"
> EndSection
>
> Section "Screen"
>          Identifier      "Default Screen"
>          Monitor         "No Monitor"
>          Device          "Xen Framebuffer Video Device"
> EndSection
>
> Section "ServerLayout"
>          Identifier      "Default Layout"
>          Screen          "Default Screen"
>          InputDevice     "Xen Mouse"
> EndSection
See if this helps. Below is my xorg.conf from my F9 pv domu. In particular, I 
would try adding to your config:

In your ''Section "ServerLayout"'', I would change
InputDevice to include the
keyboard - ''InputDevice  "Xen Mouse" "Generic
Keyboard"''.

In your ''Section "Screen"'', I would remove the
Monitor line, and add something
like my DefaultDepth and ''SubSection "Display"''
lines.

Good luck!

# Xorg configuration created by system-config-display

Section "ServerLayout"
        Identifier     "single head configuration"
        Screen      0  "Screen0" 0 0
        InputDevice    "Keyboard0" "CoreKeyboard"
EndSection

Section "InputDevice"
        Identifier  "Keyboard0"
        Driver      "kbd"
        Option      "XkbModel" "pc105"
        Option      "XkbLayout" "us+inet"
EndSection

Section "Device"
        Identifier  "Videocard0"
        Driver      "fbdev"
EndSection

Section "Screen"
        Identifier "Screen0"
        Device     "Videocard0"
        DefaultDepth     24
        SubSection "Display"
                Viewport   0 0
                Depth     24
        EndSubSection
EndSection

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Paul Schulze

2008-Jun-15 21:19 UTC

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Re: [Xen-users] PV DomU VNC screen black and Xorg error

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Am 15.06.2008 um 16:30 schrieb jim burns:
> See if this helps. Below is my xorg.conf from my F9 pv domu. In  
> particular, I
> would try adding to your config:
>
> In your ''Section "ServerLayout"'', I would
change InputDevice to
> include the
> keyboard - ''InputDevice  "Xen Mouse" "Generic
Keyboard"''.
>
> In your ''Section "Screen"'', I would remove the
Monitor line, and
> add something
> like my DefaultDepth and ''SubSection "Display"''
lines.
>
> Good luck!
Hi again,

Thanks Jim for trying to help me, but the solution for the problem  
wasn''t all that easy. And yeah, this means I solved the mystery:

The culprit is xserver-xorg-core in Ubuntu Hardy, which according to  
an OpenSuse 10.3 bug report (https://bugzilla.novell.com/show_bug.cgi? 
id=285523) doesn''t support the pixclock value (whatever that is) set  
by the Xen framebuffer. I originally dismissed the idea of this being  
relevant, since the problem was known for quiet a while there and I  
thought since it was solved about a year ago, the patch should have  
made its way into the Xorg 7.3 tree already or at least adapted by  
Ubuntu (I''ll have to contact the package maintainer about that  
later), but it turns out, that the solution of OpenSuse was dead on.  
This also means that the same bug might or might not be present in  
other distributions that use Xorg 7.3 too.

Here is what I did (for everyone who is interested):

1) Installing the build dependancies and getting the xserver-xorg- 
core sources for a rebuild:

sudo apt-get build-dep xserver-xorg-core
apt-get source xserver-xorg-core


2) Creating the patch file (this is a recreation of the OpenSuse 10.3  
patch, adjusted for use with the debian build tools)

cd xserver-xorg-<Hit TAB>
cat << EOF > debian/patches/999_xen_pvfb_pixclock.patch
diff -Naur xorg-server-1.4.1~git20080131.orig/hw/xfree86/fbdevhw/ 
fbdevhw.c xorg-server-1.4.1~git20080131/hw/xfree86/fbdevhw/fbdevhw.c
- --- xorg-server-1.4.1~git20080131.orig/hw/xfree86/fbdevhw/ 
fbdevhw.c     2008-06-15 21:18:54.000000000 +0200
+++ xorg-server-1.4.1~git20080131/hw/xfree86/fbdevhw/fbdevhw.c   
2008-06-15 21:19:56.000000000 +0200
@@ -245,7 +245,7 @@
                 set->green.length == req->green.length &&
                 set->blue.length == req->blue.length &&
                 set->xres == req->xres && set->yres ==
req->yres &&
- -               set->pixclock == req->pixclock &&
+               ((set->pixclock == req->pixclock) || !set->pixclock)
&&
                 set->right_margin == req->right_margin &&
                 set->hsync_len == req->hsync_len &&
                 set->left_margin == req->left_margin &&
EOF

And adding it to the list of patches that are used to build the package:
echo "999_xen_pvfb_pixclock.patch" >> debian/patches/series


3) Editing the changelog, so my version overwrites the current  
version of the package, but is overwritten if a new version of the  
package comes out, and I can or rather have to update the package. I  
added the following lines to the beginning of debian/changelog in the  
current directory:

- --- debian/changelog ---
xorg-server (2:1.4.1~git20080131-1ubuntu9.2.1) hardy-security;  
urgency=low

   * Fix Xen PV guest issue:
     + 999_xen_pvfb_pixclock.patch

  -- My Name <my@mail.address>  Sun, DOM MON YEAR HH:MM:SS TZ
- ---

You''ll have to adjust the last line, so it fits your name, mail  
address and time (I''m sure there''s a tool to create a basic
entry
automatically, but I just use copy/paste anyways, so same  
difference). If you don''t want to have to build the package every  
time it is updated by Ubuntu, you will have to pin it, but since  
X.org is regularly subject to security updates and a basic package  
for every desktop that many others depend on, I don''t recommend it.


4) Building the package (the most simple thing ever, it just takes  
alot of time):

debuild


5) Installing it:

dpkg -i ../xserver-xorg-core-<Hit TAB>


This solution did the trick for me in terms of Xorg starting up, but  
when I open the VNC window, provided by Xen, the colors are all  
screwed up and the mouse acts funky. So for an initial setup, this is  
ok, but I''ve decided to rather use Vino from there after all. Though  
I hope this will help at least some people.

Cheers,


Paul.

- --
Paul Schulze
avlex@gmx.net
Public Key: http://solaris-net.dyndns.org/keys/key_avlex.asc

"Making mistakes is human,
but to really fuck things up you need Computers"
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jim burns

2008-Jun-16 00:15 UTC

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Re: [Xen-users] PV DomU VNC screen black and Xorg error

On Sunday June 15 2008 05:19:48 pm Paul Schulze wrote:> This solution did the trick for me in terms of Xorg starting up, but
> when I open the VNC window, provided by Xen, the colors are all
> screwed up and the mouse acts funky. So for an initial setup, this is
> ok, but I''ve decided to rather use Vino from there after all.
Though
> I hope this will help at least some people.
Nice job tracking down that bug. As for the new problems, I had those at first 
too. Some vncviewers support changing the bit depth. Try -LowColourLevel, 
or -bgr233, etc. The mouse issues sound like you need the evtouch tablet 
driver. If your distro doesn''t provide it, try the link mentioned in
the xen
docs section ''A.4.3 Mouse issues, especially under VNC'':

http://stz-softwaretechnik.com/~ke/touchscreen/evtouch.html 

You are going to have to play with the MaxX/MaxY values - I set them to the 
screen resolution.



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Xen users - Jun 2008 - PV DomU VNC screen black and Xorg error

[Xen-users] PV DomU VNC screen black and Xorg error

[Xen-users] PV DomU VNC screen black and Xorg error

Re: [Xen-users] PV DomU VNC screen black and Xorg error

Re: [Xen-users] PV DomU VNC screen black and Xorg error

Re: [Xen-users] PV DomU VNC screen black and Xorg error