VIRTUALBOX SIERRA RESOLUTION STUCK HOW TO
Last thing I've seen is around vboxvideo.ko but I don't know how to ensure it is loaded (tried with lsmod but no vboxvideo here) or to load it (I tried loading it with modprobe and insmod but both give me "ERROR: could not insert 'vboxvideo': Invalid argument" error). xrandr still gives only 640x480 as available resolution.Rebooted several times between new installation and tests from stuff found on the internet.Virtual box guest additions installed from /run/media// VBox_GAs_6.1.0/autorun.sh.VirtualBox version 6.1.0 r 135406 (last at this time) with extensions installed.I'm willing to use openSUSE Leap 15.0 under VirtualBox but it is for now not user friendly since the screen resolution is stuck to 640x480, here is my configuration:
VIRTUALBOX SIERRA RESOLUTION STUCK DRIVER
Thanks for your answer my answers inline above, but in any case I think the issue is not VirtualBox side but openSUSE side, a driver missing or not loaded so that virtual graphics card is properly recognized and, at least better resolutions are available, at best "Auto-resize Guest Display" option works properly.
Have you enabled “ Seamless Windows”? – => No, but I can't since the option is disabled (greyed) in "View" menu.Respect to the openSUSE Guest running on a Windows 10 host: