[vbox-dev] 3d pass-through and gnome-shell ?

[Hans de Goede]

Hi,

On 27-06-17 11:34, Michael Thayer wrote:
> Hello Hans,
> 
> 26.06.2017 18:12, Hans de Goede wrote:
> [Discussion of 3D problems in Fedora VirtualBox guests and ld.so.conf
> trickery used to put 3D libraries in place, but not completing in time
> for the display manager.]
>> Ok, I understand, this is easy to fix:
>>
>> 1) Split out the bits which do the ld.so.conf trickery from the rest of
>> the guest service, so that we've a binary or script which will run, do
>> the ld.so.conf stuff if necessary and then exit. The idea here is that
>> the exit of the process indicates the ld.so.conf stuff is done.
>>
>> 2) Give this its own systemd .service file with:
>>
>> [Unit]
>> Before=display-manager.service
>>
>> [Service]
>> Type=oneshot
>> RemainAfterExit=yes
>>
>> And then systemd will not start gdm until the ld.so.conf stuff has
>> finished
>>
>> 3) profit :)
> 
> Or just add display-manager.service to the Before= line in
> vboxadd.service.

But that service keeps running right ? Is it of the forking type ?
And does it do the ld.so setup before forking ? If not then things
will still be racing, because the service must not just have started,
it must also have done the ld.so setup.

> In fact, the other things in there are needed for the
> 3D support detection too.  I tested this and it lets me start both a
> Wayland session and an accelerated X11 one.

Cool!

>> Note we would still need to figure out a way to make gdm use X11 if
>> Wayland will not work with the 3d pass-through, but that is easy too,
>> simplest way is to edit:
>>
>> /etc/gdm/custom.conf
>>
>> And in the [daemon] Section set:
>> WaylandEnable=false
> 
> I did think of this, though given the number of problems our 3D has on
> Linux guests I am still wondering whether it is worth it just now.

Would it not be better to try and fix those issues ? I believe that 3D
pass through is an important feature to have.

> For example Fedora 26 Alpha hangs loading the session (or at boot with the
> Before= fix) when 3D is enabled.

Yes this is what I'm seeing (I'm using Fedora 26 beta) note it does not
hang it just shows a black screen, you can do host-key + F3 (so send
ctrl+alt+F3) to get a text console. Looking at ps aux output it seems
that gnome-shell is not running, I've not yet dug any deeper.

Regards,

Hans