App issue with Windows 10 (guest) and Windows 11 (host) [EDITED]

[attilio_gelosa]

Hi,

I'm having issues playing a Windows 10 guest on a Windows 11 host.

Host: Windows 11 64-bit (21H2, OS Build: 22000.918)
Microprocessor: 11th Gen Intel(R) Core(TM) i7-1165G7 @ 2.80GHz 2.80 GHz
Installed RAM: 32.0 GB (31.7 GB usable)

Guest: Windows 10 (21H2, OS Build: 19044.1949)
Microprocessor: 4 vCore
Ram: 8 GB
Hard disk: 85 GB

Description: I use the guest machine(s) as a development machine (in particular using Visual Studio 2019 and Visual Studio 2022). 

Randomly, Visual Studio freezes (particularly when pop-ups open, but also in other situations), freezes for a few moments, and then either resumes or restarts.

Any suggestions?
What do you need for a possible more in-depth analysis?

Attached is the support data collected from one of the VM that suffers from the problem...

Thank you!

[scott28tt]

Nothing is attached to the post.

Providing host hardware and VM hardware configurations seems sensible.

[wila]

Hi,

Do you need to use Hyper-V or WSL at the host?
Your vmware.log has this line:

2022-09-07T07:27:29.544Z In(05) vmx Monitor Mode: ULM

Which means that you are running in User Level Mode and thus Workstation cannot use VMware's hypervisor, but instead it has to go through the Hypervisor API that Microsoft provides.

Only when Monitor mode returns CPL0 it is running in ring 0, a.k.a. no hypervisor.

Monitor mode CPL0 (Current Privilege Level 0) is required for VMware Workstation to be able to use their own hypervisor.

See also:

https://communities.vmware.com/t5/VMware-Workstation-Pro/MikroTik-RouterOS-boot-speed-is-drastically...

In order to turn off ULM/Hyper-V mode, run the following command at the host in windows command-line with Administrator privileges:

bcdedit /set hypervisorlaunchtype off

Reboot the system to activate your changes.

If you want to go back to Hyper-V mode again, then you can enable it like this:

bcdedit /set hypervisorlaunchtype auto

See also:

• Workstation 16 Pro Error "Virtualized Intel VT-x/EPT is not supported on this platform
• https://kb.vmware.com/s/article/2146361

Note that you also might have to disable Memory Integrity.

Windows Security -> Device Security -> Core Isolation details

Don't forget to reboot the host after making any of these changes.

--
Wil

[attilio_gelosa]

Hi @wila ,

thank you for your answer.

I test "extensively" tested your suggestion and it works! Thank you, thank you, thank you!

Aside question: it seems that your suggestion not only solves my problem but speeds up the VM execution speed. Is it possible or it's only a "placebo" side effect?

Regards,

Attilio

[wila]

Hi,

Not a placebo effect.

VMware's hypervisor is more performant and has more features then the one that Microsoft provides via their API.
Personally I wish it was more clear to a user which hypervisor is used.

--
Wil