Linux guest additions text mode video problems after X server starts -> fixed as of 10 Oct 2011

[ulogic]

With Linux guest additions version 4.1.0 and 4.1.2, Linux guests have either corrupt video or blank video in text mode consoles after the X server has started. In the kernel boot options, I am using vga=0x317. When booting to runlevel 3, the consoles all work correctly. After running startx or booting in runlevel 5, you can switch to a text console with left control-left alt F1 through F6. Under Fedora 14 as a guest, the screens are completely black. Under SuSE 11.4 as a guest, TTY1 has distorted colors and the fonts are 4 times larger than they should be, and TTY2 through TTY6 are black. When exiting from the X server after startx, the console is unusable. When shutting down or rebooting the guest machine from runlevel 5, you can't read the console shutdown messages.

You can switch back to the X server with left alt F7, and the display is fine there.

Reverting back to 4.0.x guest additions do not exhibit this problem. I have verified that there are no problems switching back to text mode with version 4.0.8, 4.0.10, and 4.0.12 guest additions under VirtualBox 4.1.2.

[michael]

I am aware of this, though I haven't seen it recently and thought it was fixed. I will investigate when I have time.

[Perryg]

Adding my name to the list. TTY in Ubuntu 11.04 (unity or not) totally useless. Framebuffers all wrong and distortions.

[pwt]

Adding my name to the list. Bug present in debian testing. See  http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=638941

[fdekruijf]

Adding my name to the list. Bug present in openSUSE 12.1 Milestone 5 as the guest. See attachment.

[fdekruijf]

screenshot of VirtualBox window

[RomaHagen]

I'm also interested in fixing this bug. My guest system is Arch Linux. Feel free to ask any info you need.

[fneurieser]

I'm also interest in fixing. My guest system is CentOS 5.7

[michael]

I can reproduce this, it is just a problem of finding the time to solve it, I'm afraid. If anyone feels strongly enough about fixing this to play with the source code a bit though, you might take a look at these places:

 http://www.virtualbox.org/browser/trunk/src/VBox/Additions/x11/vboxvideo/vboxvideo.c#L1306  http://www.virtualbox.org/browser/trunk/src/VBox/Additions/x11/vboxvideo/setmode.c  http://www.virtualbox.org/browser/trunk/src/VBox/Additions/common/VBoxVideo/Modesetting.cpp

[irishespresso]

michael, is there anything in the mode registers that one could look at that would help find the problem? I'm wondering if width, height, pitch, or bits per pixel is being set too high, or perhaps to a garbage value.

[irishespresso]

How does one turn on the TRACE_LOGs, and where is the trace written too?

[michael]

TRACE_LOG statements are enabled if DEBUG is defined while compiling, and the log output goes to /var/log/Xorg.*.log. My suspicion is that something is not getting set up right with the (traditional) VGA registers. I am not so fluent with them that I can tell just by looking if they are set right :)

[irishespresso]

Thanks. Is there a way to get a dump of the traditional VGA registers?

[michael]

Two ways immediately spring to mind. One would be to check them from the video driver code and TRACE_LOG them. The other would be to rebuild a debug version of the main VirtualBox code and add some logging in vgaIOPortRead and vgaIOPortWrite in src/VBox/Devices/Graphics/DevVGA.cpp. To tell the truth I am surprised that there is none there now.

[michael]

People experiencing this might like to give the following Additions build a try:

https://www.virtualbox.org/download/testcase/VBoxGuestAdditions-r74284.iso

It is a snapshot from the development branch, so the usual warnings apply (although it shouldn't be very different to the 4.1.4 Additions). irishespresso, for your interest, the relevant changeset (hoping it fixes your issue) is r38929.

[irishespresso]

Michael, tonight I installed Virtualbox 4.1.4, replaced the 4.1.4 Additions iso with your 4.1.51 test iso, created a 32-bit Natty Narwhal VM, installed dkms in it, installed the 4.1.51 guest additions in it, and then rebooted it. After the reboot, I did alt-ctrl-F1 to get to the console. It looked fine. Then I did a shutdown, and the shutdown screen looked fine, too. In short, it looks good from my end :-) . Please make this part of the 4.1.6 release.

[irishespresso]

For the record, it works with 64-bit Natty, too.

[Perryg]

I just built and tested from SVN on 32 and 64. Works like a charm. Great work Michael.

[fdekruijf]

OK on openSUSE 12.1 Beta 1

[ulogic]

As the original reporter of this issue, I am glad to report VirtualBox 4.1.4 with the 4.1.51 guest additions iso fixed the issue with my various installations. Thank you very much.

[michael]

Backported the fix to version 4.1, and it will be present in any future releases of 4.1 or later. Sorry for the inconvenience and thanks for testing.

[frank]

Fix is part of VBox 4.1.6.