virtualbox.org

I'm running VirtualBox 6 on Windows 10. I've imported a valid appliance (running fine on another windows 10 laptop). But on my laptop the VM stops with a Guru Meditation error.

I've attached the log file. I didn't see any obvious errors but I'm hopeful that someone else will be kind enough to take a look.

Thanks!

Please withdraw the partial log and replace it with a zipped version of the complete log.

Done. Sorry about that.

You have a triple fault, which means that the VM was in such an unstable state that it crashed again while in the crash handler. This makes it hard to know what caused the original crash. Normally it is when the VM has done something really nasty, such as running corrupted guest boot code.

When you say "imported a valid appliance", that means you ran "File|Import" again? Was the last VM really installed from that same appliance, or was it perhaps copied to a USB stick and then to the new PC where you tried to import the copy?

I notice that you have not installed the extension pack on this second host. That means that features that rely on the extension pack (main USB2/3 and VRDP) will not work on host #2.

I assume you're aware that FreeBSD is not fully supported, e.g. no Guest Additions.

Thanks much for the reply. The last couple of hours we've installed VB6 and the appliance in question on a couple of other machines and it runs fine.

The problem definitely has something to do with only the original problem laptop:
Inspiron 7786
Intel i7-8565U CPU
16.0 GB RAM
64-bit Windows 10 pro v1903

And the weirdest part is that this laptop is nearly identical to another new one which runs the appliance flawlessly.

We're now at the point of comparing the 2 new Inspiron laptops line-by-line to see if there are any subtle differences. Frustrating.

Thanks again for your time. We are very appreciative of any fresh ideas.

VBox log file wrote:

Code: Select all

00:00:02.556774 Structured Extended Feature Flags Enumeration (leaf 7):
00:00:02.556774   Mnemonic - Description                                  = guest (host)
[...]
00:00:02.556798   IBRS_IBPB - IA32_SPEC_CTRL.IBRS and IA32_PRED_CMD.IBPB  = 0 (1)

VirtualBox does not provide the SPEC_CTRL MSR to the guest OS and indicates this in the CPUID leaf 7.

VBox log file wrote:

Code: Select all

00:00:10.104135 IEM: rdmsr(0x48) -> #GP(0)
00:00:10.194359 Changing the VM state from 'RUNNING' to 'GURU_MEDITATION'

The guest tries to read the SPEC_CTRL MSR (0x48), probably without checking for its existence.

The SPEC_CTRL MSR is part of the Spectre/Meltdown mitigation.

Educated guess:
Enabling the SPEC_CTRL MSR may help here (VBoxManage modifyvm <vmname> --spec-ctrl on), but it may not be enough.
Alternatively, disable Spectre/Meltdown mitigation in the guest OS.

ftho - you sir (madam?) are a steely-eyed-missle-man. It worked!!!

Implemented the "VBoxManage modifyvm <vmname> --spec-ctrl on" bits on the appliance and the VM fired right up.

Excellent catch! Thanks a million!

Indeed an excellent catch @fth0!!!
Just one question; how did you know that MSR 0x48 is the SPEC_CTRL one? From the log, or somewhere else?

Marking as [Solved].

socratis wrote:how did you know that MSR 0x48 is the SPEC_CTRL one? From the log, or somewhere else?

From an excellent source for x86 processor information: https://www.sandpile.org/x86/msr.htm. Also see the whole site: https://www.sandpile.org/

Oh wow, it's impressive how condensed the information in there is! Thanks fth0, that's a keeper...