[vbox-dev] Guest OS, segmentation faults under certain OS setups.

[Fabio Erculiani]

I think I've found a weird, reproducible (on my machine) critical
issue with VirtualBox 3.2.4. Here's my setup:

CPU: model name      : Intel(R) Core(TM) i5 CPU         750  @ 2.67GHz
GPU: NVIDIA (8600GTS and even with GTX465)
RAM: 8GB DDR3
Chipset: Intel P55 (MSI GD-55)
Kernel: Linux mars 2.6.34-sabayon #1 SMP Mon May 31 16:00:15 UTC 2010
x86_64 Intel(R) Core(TM) i5 CPU 750 @ 2.67GHz GenuineIntel GNU/Linux
Kernel config: http://distfiles.sabayon.org/sys-kernel/linux-sabayon-patches/config/sabayon-2.6.34-amd64.config
VirtualBox ver: 3.2.4, same for guest-additions and vboxdrv
Guest OS: Sabayon 5.3 amd64/x86 (doesn't matter), ISO images are
publicly available
Host OS: Sabayon/Gentoo

If I install two instances of the Guest OS above on different
partitions, both of them get unusable due to random segmentation
faults being thrown.
The partition layout is as this:
- sda1 /boot OS1
- sda2 / OS1
- sda3 swap OS1
- sda5 LVM OS2
  => inside there are root volume and swap volume
Bootloader: GRUB2

OS1 is 64bit
OS2 is 32bit

Once I remove sda5 (or sda1,2,3, in other words, once I keep just one
OS on the virtual drive) and reboot, the remaining OS is back to a
healthy state (no more random segfaults).
How's that possible?
VT and Nested paging are enabled, 3D accel is enabled, RAM is 1G and
OS profile is "Gentoo (64bit)".
It is perfectly reproducible on my PC, I have not tested the same
setup on others and I exclude any host hardware issue.

Let me know if you need anything more specific.

-- 
Fabio Erculiani
http://www.sabayon.org
http://www.gentoo.org