This blog post is not about the L1 Terminal Fault (L1TF -> VMware KB56931) but about the HTAware Mitigation tool version 1.0.0.9 (HTAwareMitigation-1.0.0.9.zip) that seems to have issues when used on single hosts (instead of clusters) – here is the problem that I have observed.

You run the command:

Set-HTAwareMitigationConfig -VMhostName <hostname> -Enable

Followed by

Get-HTAwareMitigationConfig -VMhostName <hostname>

 

As you might see the “Set-HTAwareMitigationConfig -VMhostname <hostname>” command doesn’t seem to do anything!

 

Therefore, at this moment a quick fix could be setting the value manually under the host advanced settings:
VMkernel.Boot.HyperthreadingMitigation = true

 

After that the Get-HTAwareMitigationConfig can be used to confirm the setting

 

So all there is left now to do: reboot!

 

This settings could be done by various scripting tools – but if you only have a few host the manually way might be the fastest way to go 🙂

Feel free to provide your own fix in the comments section bellow!