VMs crash or infinite reboot loop in Win 11

[dvhsfan]

I had a VM running Ubuntu 20.04.4 LTS using Hyper-V with Virtualbox v6.1.32 I upgraded to Virtualbox v6.1.34. I then attempted to create and install a WIn 10 VM with no success. I tried starting my Ubuntu VM just as a sanity check and it crashes with a bunch of info displayed. I've downgraded back to v6.1.32. I've deleted and recreated the Ubuntu VM several times on both 6.1.32 and 6.1.34. All of these crash. Win 10 VM doesn't work either on both 32 and 34.
I think the problem started when KB5012643 and/or KB5012159 was installed but can't be sure. At the same time, KB2267602 (Version 1.363.1117.0) and KB2267602 (Version 1.363.1026.0) were also installed.

Based on another thread, I've looked for "hardware virtualization" changes in the anti-virus but didn't find any.

[mpack]

Provide a VM log file. Make sure the VM is fully shut down, then right click it in the manager UI. Select "Show Log" and save "VBox.log" (no other file) to a zip file. Attach the zip here.

[dvhsfan]

I haven't been able to get the infinite reboot loop for WIn 10 guest to occur again. While trying to replicate this, another issue occurred. The Windows 10 installer is now stuck. Log for installer stuck issue is attached. I will continue to attempt to get the infinite reboot loop to occur again.

I also had issues with Ubuntu guest panic screen -> This Ubuntu issue is reported at viewtopic.php?f=3&t=105941

[mpack]

You have Hyper-v enabled, probably the cause of all your problems.

00:00:48.307039 HM: HMR3Init: Attempting fall back to NEM: VT-x is not available
00:00:48.322555 NEM: info: Found optional import WinHvPlatform.dll!WHvQueryGpaRangeDirtyBitmap.
00:00:48.322603 NEM: WHvCapabilityCodeHypervisorPresent is TRUE, so this might work...

See HMR3Init: Attempting fall back to NEM (Hyper-V is active).

[dvhsfan]

mpack,

I thought that Virtualbox worked with Hyper-V since version 6.1.28 - see https://www.virtualbox.org/ticket/20536
No VM will start on Windows 11 host => fixed in 6.1.28

Changed 7 months ago by klaus
Status changed from new to closed
Resolution set to fixed
Summary changed from No VM will start on Windows 11 host to No VM will start on Windows 11 host => fixed in 6.1.28
This incompatibility with the Windows Hypervisor related interface in Windows 11 (host) should be fixed with VirtualBox 6.1.28.

Using the Windows Hypervisor (Hyper-V) is working again. However, the performance is unchanged, i.e. still very noticeably lower than with VirtualBox's own hypervisor code, so it can make sense to disable Hyper-V. You decide.

[scottgus1]

I thought that Virtualbox worked with Hyper-V since version 6.1.28

Some Virtualbox-on-Hyper-V situations worked before then. When Windows 11 came out, the devs started compatible-izing Virtualbox, and a bug or three crept in. Our forum guru 'fth0' has done some troubleshooting and pins down these possibilities to try (HCVI = Microsoft 'Memory Integrity'):
6.1.32 without Hyper-V
6.1.30 with Hyper-V but without HVCI
6.1.26 with Hyper-V and HVCI.