VMs won't run properly with more than one CPU assigned

[edson_v_schmitt]

Hello there!

Ok ... I'll share the long story version and hopefully it will provide enough context for anyone to suggest solutions.
2 weeks ago I got a brand new laptop (G15 5511 running W11 with an i7-11800H and 16 GB of RAM) and I since it was capable of running VMs well enough I brought over a W10 Guest OS I had from another computer and everything simply worked ... after the initial setup I even increased memory and number of CPU cores and everything was smooth sailing.

About a week ago ... all the bloatware started getting under my nerve and I decided to do a full reinstall of W11.

Today, when I decided to relaunch the same VM from past weeks I ran into a system that simply won't work ... I don't know how else to describe it but it is simply sluggish performance to a point it becomes unusable.

I didn't give up and kept trying different configurations until I came across something ... this extremely sluggish performance seems to happen whenever I have more than one CPU core associated with any images ... it happens to my W10 guest and even to a Linux Mint guest ... anything more than 1 CPU core and the system simply doesn't work.

To provide added context ... I'm starting a brand new VM ... booting off of the w10 ISO ... and the same issue happens ... hopefully the logs will prove useful.

At this point I have tried repairing the VirtualBox installation, removing and installing it again, checking the BIOS to make sure virtualization options were turned on, etc, etc ...

Since it worked before my full W11 reinstall ... I'm sure there must be something missing from my new windows install ... a driver, a config ... what ?

The log file is from starting up the ISO ... letting it run a couple of minutes (not getting anywhere) ...

[scottgus1]

Looks like you're getting hit by the 6.1.32 bug.

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.

To turn off Hyper-V see HMR3Init: Attempting fall back to NEM (Hyper-V is active).

[edson_v_schmitt]

Thank you so much for your help!

VBS must have been enabled by default with the new W11 install ...

Disabling it under "Core Isolation" -> "Memory Integrity" -> "OFF" did the trick ...