[vbox-dev] BLUF: Consider enabling 3D acceleration by default (as least for KDE-based Linux guest OSs)

[Klaus Espenlaub]

Hello Nate,

On 2024-03-08 18:10, Nate Graham via vbox-dev wrote:
> Hello! I'm Nate Graham from KDE. We're tracking an issue that causes 
> Linux guest OSs with KDE Plasma 6 to fail when 3D acceleration is 
> disabled: https://bugs.kde.org/show_bug.cgi?id=481937. The changes made 
> in Plasma 6 that resulted in this issue are unfortunately not easily 
> revertable, and 3D acceleration improves the UX in general for our 
> systems, so our developers aren't feeling a strong incentive for to try.

I can sympathize, but with VMs it's pretty common to not have 3D enabled 
(it'd be surprising if VMware Workstation or QEMU/kvm do this by 
default). I read the bug tracker entry and couldn't spot many useful 
facts unfortunately. Can't tell if the same works with VMware 
Workstation with 3D disabled. Because if it does then the issue is a bug 
in VirtualBox.

We'll try to let a developer investigate this in more details. Black 
screen could be also caused by too little VRAM being configured (and by 
enabling 3D in the VirtualBox GUI the VRAM size is automatically bumped 
to 128MB which can work around the issue), thanks to the quite simple 
minded VRAM allocation code in the Linux kernel...

> I'd like to discuss the possibility of enabling 3D acceleration by 
> default--at least for as least for KDE-based Linux guest OSs.

The problem with this idea is that VirtualBox has no idea whatsoever 
which desktop environment will be used in a particular VM. So we'd have 
to enable it more or less wholesale, and then the argument with the 
additional attack surface for VM escapes comes into play.

In any case, thanks for reaching out.

Klaus