virtualbox.org

Host: Fedora 23 x86_64 on Lenovo W541 Mobile Workstation
i7 quad core, HT enabled, VTx enabled
16G DDR3, 500G SSD

Guest: W10 64-bit on vbox 5.0.14_RPMFusion r105127 and Guest Additions
8G system memory
PIIX3 chipset
I/O APIC enabled
Video Memory: 256M
Scale Factor 100%
no display acceleration.

Problem: Screen suddenly changes aspect ratio from 16:9 to 4:3, and 16:9 choices are no longer available in the guest's display resolution drop list.

I have attached the VM log.

The native resolution of my display is 1900x1080, and that's what I set up my W10 guest to be. I have it running in Full Screen mode, with the Guest Additions virtual cd connected.

It runs for a while at 1900x1080, but after a while, it just suddenly reverts to 1600x1200, which is useless on my 16:9 display.

Here is the part of the log where that happens. What am I doing wrong?

00:14:44.390821 VMMDev: Guest Log: VBoxMP::DxgkDdiStartDevice: using HGSMI
00:14:44.462441 VBVA: InfoScreen: [0] @0,0 1920x1080, line 0x1e00, BPP 32, flags 0x1
00:14:44.462471 Display::handleDisplayResize: uScreenId=0 pvVRAM=00007f03b0000000 w=1920 h=1080 bpp=32 cbLine=0x1E00 flags=0x1
00:14:44.462512 GUI: UIFrameBufferPrivate::NotifyChange: Screen=0, Origin=0x0, Size=1920x1080, Sending to async-handler
00:14:44.462568 GUI: UIMachineView::sltHandleNotifyChange: Screen=0, Size=1920x1080
00:14:44.462581 GUI: UIFrameBufferPrivate::handleNotifyChange: Size=1920x1080
00:14:44.462595 GUI: UIFrameBufferPrivate::performResize: Size=1920x1080, Directly using source bitmap content
00:14:44.678816 OHCI: USB Suspended
00:14:44.722709 EHCI: USB Suspended
00:14:45.456116 GUI: UISession::sltAdditionsChange: GA state change event came, notifying listeners.
00:14:45.466269 GUI: UISession::sltAdditionsChange: GA state really changed, notifying listeners.
00:14:45.466286 GUI: UIMachineLogicFullscreen: Additions-state actual-change event, rebuild multi-screen layout
00:14:45.466643 GUI: UIMultiScreenLayout::update: GUI/AutomountGuestScreens is disabled
00:14:45.466666 GUI: UIMachineViewFullscreen::adjustGuestScreenSize: Adjust guest-screen size if necessary.
00:14:45.466670 GUI: UISession::sltAdditionsChange: GA state change event came, notifying listeners.
00:15:32.020362 Display::handleDisplayResize: uScreenId=0 pvVRAM=00007f03b0000000 w=1920 h=1080 bpp=32 cbLine=0x1E00 flags=0x1
00:15:32.020405 GUI: UIFrameBufferPrivate::NotifyChange: Screen=0, Origin=0x0, Size=1920x1080, Sending to async-handler
00:15:32.020453 GUI: UIMachineView::sltHandleNotifyChange: Screen=0, Size=1920x1080
00:15:32.020477 GUI: UIFrameBufferPrivate::handleNotifyChange: Size=1920x1080
00:15:32.020486 GUI: UIFrameBufferPrivate::performResize: Size=1920x1080, Directly using source bitmap content
00:15:32.036189 Display::handleDisplayResize: uScreenId=0 pvVRAM=00007f03b0000000 w=1600 h=1200 bpp=32 cbLine=0x1900 flags=0x1
00:15:32.036255 GUI: UIFrameBufferPrivate::NotifyChange: Screen=0, Origin=0x0, Size=1600x1200, Sending to async-handler
00:15:32.036338 GUI: UIMachineView::sltHandleNotifyChange: Screen=0, Size=1600x1200
00:15:32.036351 GUI: UIFrameBufferPrivate::handleNotifyChange: Size=1600x1200
00:15:32.036365 GUI: UIFrameBufferPrivate::performResize: Size=1600x1200, Directly using source bitmap content

In the GUI, go to File|Preferences|Display|Maximum_Guest_Screen_Size and set it to "None". You can also try it on automatic, if it isn't already that.

mpack wrote:In the GUI, go to File|Preferences|Display|Maximum_Guest_Screen_Size and set it to "None". You can also try it on automatic, if it isn't already that.

It was set to "Automatic", so I changed it to "None" and the problem seems to be solved.

Good tip. Thanks!

Thanks for confirming. If it's on "Automatic" then it will generally offer new sizes (to the guest OS) which retain the current aspect ratio. So I can't tell you why the preferred aspect ratio changed, but now that you've changed it back you would probably find that "Automatic" can be used again. Or you can just leave it how it is now.

mpack wrote:Thanks for confirming. If it's on "Automatic" then it will generally offer new sizes (to the guest OS) which retain the current aspect ratio. So I can't tell you why the preferred aspect ratio changed, but now that you've changed it back you would probably find that "Automatic" can be used again. Or you can just leave it how it is now.

I think I'll just leave it as "None", since "Automatic" was doing things behind my back that I didn't really like.

Thanks again for the great help!