Guest Ubuntu 15.04 (64 bit) crashes on Host Windows 7 AND 10 (each 64bit) after upgrading to VB v5.0 unless nested paging left OFF

[Aweman]

I upgraded to VirtualBox 5.0.0-101573 three weeks ago, from VirtualBox v4.3.30. Today I also tried Testbuild 5.0.1-101908.

With the new versions 5.0.X I cannot use my Ubuntu 15.04 (64 bit) VM anymore, unless I turn nested paging off. When it is turned on Ubuntu crashes and restarts when I try to access the VM. I tried it on both Windows 7 and Windows 10 Host (each 64 bit).

For now, I reverted to VirtualBox v4.3.30 which runs it fine.

It looks like it is the same error as #14262 and #14263, although Guest/Host are the opposite.

[Aweman]

I have recorded a video, which shows the behaviour of the VM when I tried to install a new Ubuntu VM, which is the same behaviour on my existing Ubuntu VM.  https://www.dropbox.com/s/m62rx9uc1qbdyf5/Ubuntu%2015.04.webm?dl=0

[frank]

Aweman, could you do the following:

VBoxManage setextradata "Ubuntu 15.04" VBoxInternal/CPUM/IsaExts/AVX 0

and enable nested paging to check if this fixes your guest as well? Thank you!

[Aweman]

Yes, it fixes the issue!

[frank]

Workaround (AVX disabled on 32-bit hosts for 64-bit VMs) is part of VBox 5.0.2. Though we hope to fix it properly.

[Aweman]

But I have 64-bit Host and 64-bit VM. Nevertheless will try it out