[Bug]: Booting Red Hat 6.1 i386 fails on AMD Zen4 Windows 11 Pro host

[frioglobal]

Version

7.2.4

Host OS Type

Windows

Host OS name + version

Windows 11 Pro Version 25H2

Host Architecture

x86

Guest OS Type

Linux

Guest Architecture

x86

Guest OS name + version

Red Hat Linux 6.1 i386

Component

Other

What happened?

I have attempted installing Red Hat Linux 6.1 i386 from an original iso, and no matter which settings I use in configuring the VM (virtualization options, hardware, peripherals), the kernel fails to boot (see screenshot).

Running this on a AMD Ryzen 9 7950X.

Interestingly, if I run the exact same version of VirtualBox on an older Intel i7, everything works just fine, Linux boots and I can install it no problem.

Thoughts on how to diagnose?

How can we reproduce this?

Boot the standard Red Hat Linux 6.1 iso, not sure if using Linux as a host the issue manifests itself, but on Windows 11 Pro/AMD Zen4, it's reproduceable, every time.

Did you upload all of your necessary log files, screenshots, etc.?

• Yes, I've uploaded all pertinent files to this issue.

[frioglobal]

On the same machine, I can install and run the same iso just fine using Bochs.

[AlexanderEichner]

Please upload a VBox.log of the affected VM, otherwise we can't help you,

[frioglobal]

Absolutely, sorry about that.

It shows the VM starting up, then I forced a shutdown after 40 seconds or so.

To test if there was a timeout somewhere I have waited much longer (~10 minutes) to see if it would proceed, with the same result.

VBox.log

[AlexanderEichner]

The log indicates you have Hyper-V enabled which VirtualBox has to make use of. Can you check whether disabling Hyper-V on your host fixes the hang (because VirtualBox can use its own hypervisor).

[frioglobal]

Interesting, from what I can tell Hyper-V is definitely disabled, see the attached screenshot. Thoughts?

[frioglobal]

I tried disabling everything, but I don't want to turn off ALL Win 11 security features.
Is there any way to understand where it gets stuck?

[AlexanderEichner]

As far as I know all the security features requires Hyper-V to be active unfortunately. FWIW I was able to reproduce the issue on a Windows 10 host using a 9950X. It looks like the guest is spinning in a loop with interrupts disabled. No idea currently why that is, it works when using our own Hypervisor, probably some state syncing issue.

[AlexanderEichner]

As a workaround you might try the following command VBoxManage modifyvm <VM name> --cpuid-set 0x00000001 0x00b40f40 0x00010800 0xf6d83203 0x178bfbaf on the Windows command line (you might need to change to the VirtualBox installation directory and replace <VM name> with the actual name of your VM). The issue here is that the Linux kernel panics very early on due to a division overflow when setting up the time in the guest using the TSC. Something there doesn't work quite right, and we are still investigating this.

[frioglobal]

It boots now!

Unfortunately then the default installation fails with this:

All options of VGA emulation produce the same result. It seems the emulated SVGA adapter doesn't support the way the OS is trying to configure and start X? This is a different issue though.

I tried to install in text mode but it fails further on, it may be an issues with RedHat Linux though.