vboxvideo.ko unable to be inserted into kernel on CentOS 6/7 -> expected behaviour

[hsundara]

Guest: CentOS 6/7, software development workstation install (with Gnome GUI) GuestAdditions: Installed and rebooted successfully, no errors.

Trying to access VM via RDP, authentication method: NULL

The screen resolution doesn't change. on ubuntu 16.04 for instance, the screen resolution changes automatically.

Looking at list of modules inserted, I see vboxsf and vboxguest but not vboxvideo.

On CentOS 7 find /lib/modules | grep vboxvideo /lib/modules/3.10.0-327.36.3.el7.x86_64/misc/vboxvideo.ko insmod /lib/modules/3.10.0-327.36.3.el7.x86_64/misc/vboxvideo.ko insmod: ERROR: could not insert module /lib/modules/3.10.0-327.36.3.el7.x86_64/misc/vboxvideo.ko: Invalid parameters

On CentOS 6 find /lib/modules | grep vboxvideo /lib/modules/2.6.32-642.6.2.el6.x86_64/misc/vboxvideo.ko insmod /lib/modules/2.6.32-642.6.2.el6.x86_64/misc/vboxvideo.ko insmod: error inserting '/lib/modules/2.6.32-642.6.2.el6.x86_64/misc/vboxvideo.ko': -1 Invalid parameters

The module is built correctly but doens't get loaded, which means I don't get the RDP resizing that I really want, in fact, that's the only reason I installed guest additions.

[hsundara]

VBox.log for CentOS 6

[hsundara]

VBox.log for CentOS 7

[hsundara]

As an added note, on Ubuntu 16.04, the vboxvideo.ko module is automatically loaded. On Ubuntu 14.04, the module is not automatically loaded, but doing insmod on the module ko file loads it and the behavior thereafter is as expected.

On CentOS 6 and 7 I am not even able to load it in the first place.

[Michael Thayer]

This is actually the expected behaviour: the kernel graphics driver is only used as of Linux 3.11, and we assume that older systems are also running X.Org as root and do not need the kernel driver.

I will see if I can do anything to make this more obvious.

[Michael Thayer]

I made a change to stop the vboxvideo kernel driver from being built at all if it cannot be used. Formerly we still needed to build a dummy for historical reasons which no longer apply.

I do not plan to change this in 5.1 releases though.

[hsundara]

Does that mean if I am using something less than 3.11, I can't get the automatic RDP resolution re-sizing?

In any case, apologies if this is the intended behavior. I wasn't able to find any documentation / Release Notes that mentioned 3.11 as minimum required, all though someone on IRC did mention it in passing.

Thanks!

[Michael Thayer]

It certainly should not mean that. It should mean that if you are using a kernel earlier than 3.11 the Additions use a different way (a user-mode X.Org driver) to get the same result. The reason that we wrote the kernel driver is that user-mode graphics drivers no longer work in recent distributions. The functionality should not change.

Are you having problems with resizing?

[hsundara]

Well, I guess I am doing something wrong then. Here's what I am basically doing (on CentOS 6 and CentOS 7 for instance, which both use pre-3.11 kernels by default)

1. I install Guest Additions on the VM.

2. In the "Display" section of the "Settings" for the VM, I enable "remote desktop server", to let's say port 3389 (default Windows RDP port)

3. Then, I boot the VM headless.

4. I connect to the machine using RDP from another host on the network. I then do something like "startx", or just use a traditional desktop manager. The resolution stays at the default, and doesn't automatically resize to my monitor's size. However, the same procedure as above when done on something that has a newer kernel, the RDP session resizes to the size of my client.

The only difference I could tell was that the "vboxvideo" module isn't being loaded in pre-3.11 kernel. Is there anything else that I should be looking for when doing _lsmod_ ? What is necessary for the "user-mode X.Org driver" to get loaded? (Based on what you have said, it appears the user-mode X.Org driver is not being loaded).

[Michael Thayer]

Looking at the /var/log/Xorg.*.log files on the guest should give you a better idea of what is happening there. I created a wiki page<1> explaining how to investigate problems with resizing in Linux guests. Unfortunately I am not very familiar with VRDP, so that part stayed blank. Feel free to submit something there.

1. https://www.virtualbox.org/wiki/DynamicResizingDebug