Unconditional upscaling of display on HIDPI systems

[Linuxhippy2]

When using VirtualBox on systems with HiDPI screens, VirtualBox unconditionally scales the VM display using the system-wide scale factor - despite a scale-factor of 100% is selected in the VM settings.

This leads to several consequences:

• Text is barely readable (glyphs simply can't be simply upscaled using whole-screen image scaling)
• The guest OS is presented a lower resolution than the host's monitor would be capable of, so even HiDPI-aware guest OSs have to run in super-ugly upscaled mode.

please see: ​https://forums.virtualbox.org/viewtopic.php?f=7&t=86809 ​https://forums.virtualbox.org/viewtopic.php?f=7&t=87184

[Linuxhippy2]

windows screen resolution dialog - ugly text, resolution too low (3840x2160 display)

[Linuxhippy2]

there should be at least a checkbox available in the VM settings to disable this behaviour ("ignore system-wide display scaling).

[Linuxhippy2]

This issue was fixed by updating the affacted Fedora-27 system.

[Linuxhippy2]

sorry for the bogus "already fixed" post - the scaling issue still persists, but instead of nearest neighbour now billinear scaling is used, which at least keeps fonts readable (but blurry)