Hyper-V-Hypervisor

no1yak · Oct 16, 2022

After getting the upgrade to 22H2 22621.674 from 21H2. I've been getting this. Error 167 The hypervisor did not enable mitigations for side channel vulnerabilities for virtual machines because HyperThreading is enabled. To enable mitigations for virtual machines, disable HyperThreading. Not using any VM's and disabling hyper threading still throws up this error. The only time this doesn't occur is when Core Isolation is turned off. Have Googled it but seems to relate to VM's, which I don't have.

Anyone have any ideas.

neemobeer · Oct 16, 2022

I would install the Powershell module "SpeculationControl" and run the check

Install module command
Install-Module -Name SpeculationControl
Agree to the prompt with either Y or A

There is only one cmdlet available, run as administrator
Get-SpeculationControlSettings

That should give you an idea of which mitigation it is complaining about. Post your output if you need further guidance

jimbo45 · Oct 16, 2022

Hi there.

@no1yak

if Hyperthreading isn't working properly or is disabled on your VM system then either your CPU in the BIOS isn't set correctly or you are using a bad VM software. You might also need to set IOMMU in the HOST hardware BIOS as well.

AFAIK if you use HYPER-V on a Windows host then Hyperthreading on a capable CPU should work. On Linux Hosts with KVM it's not an issue.

If you can't use hyperthreading properly then your GUEST (the VM system) will perform well below par. Only older celeron CPU's (and who buys computers these days with those CPUs installed) didn't have hyperthreading. Any modest laptop these days should allow cpu hyperthreading,

Cheers
jimbo

no1yak · Oct 17, 2022

jimbo45 said:
Hi there.

@no1yak

if Hyperthreading isn't working properly or is disabled on your VM system then either your CPU in the BIOS isn't set correctly or you are using a bad VM software. You might also need to set IOMMU in the HOST hardware BIOS as well.

AFAIK if you use HYPER-V on a Windows host then Hyperthreading on a capable CPU should work. On Linux Hosts with KVM it's not an issue.

If you can't use hyperthreading properly then your GUEST (the VM system) will perform well below par. Only older celeron CPU's (and who buys computers these days with those CPUs installed) didn't have hyperthreading. Any modest laptop these days should allow cpu hyperthreading,

Cheers
jimbo

@jimbo45

Thanks for the reply but, I don't use any VM's so no related software is installed. Bog standard stand alone PC with internet connection.
Will try @neemobeer suggestion.

skillingm8 · Jan 9, 2023

no1yak said:
@jimbo45

Thanks for the reply but, I don't use any VM's so no related software is installed. Bog standard stand alone PC with internet connection.
Will try @neemobeer suggestion.

Hey @no1yak, where you able to determine a fix for this issue? Currently, I'm in a similar boat with having a fresh install of Windows 11 on my new laptop with all drivers up to date (and BIOS up to date), and I'm receiving the same error you mentioned here, causing my whole system to freeze until I hard reboot the computer. I don't actually receive any BSOD UI, the screen just freezes until I hold the power button down. Every time it happens, I check the EventViewer and notice the same warning event in the log a second before the freeze happens.

I do not have any VM software running on the machine, and the only other thing I've attempted thus far is disabling some Intel Virtualization setting in the BIOS to see if that will do anything. Since this is a secondary computer for me, I will have to check back in and give an update on if that addressed the issue over the next few days, but I don't think it's the best "fix".

I also was able to install the SpeculationControl module and run the cmdlet (like @neemobeer suggested), but the information being returned didn't mean much to me and it all seemed okay.

FWIW, new laptop is an MSI Sword 15 A12UC-295.

no1yak · Jan 15, 2023

skillingm8 said:
Hey @no1yak, where you able to determine a fix for this issue? Currently, I'm in a similar boat with having a fresh install of Windows 11 on my new laptop with all drivers up to date (and BIOS up to date), and I'm receiving the same error you mentioned here, causing my whole system to freeze until I hard reboot the computer. I don't actually receive any BSOD UI, the screen just freezes until I hold the power button down. Every time it happens, I check the EventViewer and notice the same warning event in the log a second before the freeze happens.

I do not have any VM software running on the machine, and the only other thing I've attempted thus far is disabling some Intel Virtualization setting in the BIOS to see if that will do anything. Since this is a secondary computer for me, I will have to check back in and give an update on if that addressed the issue over the next few days, but I don't think it's the best "fix".

I also was able to install the SpeculationControl module and run the cmdlet (like @neemobeer suggested), but the information being returned didn't mean much to me and it all seemed okay.

FWIW, new laptop is an MSI Sword 15 A12UC-295.

@skillingm8 No the only way to stop this error is to turn off Core Isolation. I have no effects with this error, freezes or having to reboot. Sorry I can't be of help.

FlashAlliance · Jun 12, 2023

My system appeared to have the same fault today running a game and recording. I have my CPU undervolted to 1.26 @ 4800MHz Target, with a load line calibration set to 1. My gut is telling me to push the calibration up to level 3 for stability. The system had been running fine with these settings for about 3 months before this freeze occurred.

Raaaaa · Oct 5, 2023

FlashAlliance said:
My system appeared to have the same fault today running a game and recording. I have my CPU undervolted to 1.26 @ 4800MHz Target, with a load line calibration set to 1. My gut is telling me to push the calibration up to level 3 for stability. The system had been running fine with these settings for about 3 months before this freeze occurred.

Yes I have the same problem, did you figure out the solution after that? I got this error in the event viewer after a freeze, I tried restore point, the problem stop occurring for a whole day, then appear the next day night when playing a game, still finding for solution, but I'll try not to restore point and see what is the problem, I have not update the newest windows and stop it for a couple weeks, cuz the newest update kept freezing my laptop, even after reinstall windows

thecaretaker · Mar 30, 2024

I started getting the Event ID 167 The hypervisor did not enable mitigations for side channel vulnerabilities for virtual machines because HyperThreading is enabled. I turned HyperThreading off in the BIOS and I no longer get the event show up in the Event Viewer logs. My PC doesn't seem any slower. It seems connected with Core Isolation in Windows Security which for some strange reason doesn't like HyperThreading being enabled. Hope this helps anyone with the same issue.