In case your VM is running slow, you should consider disabling Side Channel Mitigation in VMware. Here's how you can do it.

On some Windows machines, especially on laptops, the Side Channel Mitigation is enabled automatically. This selection is also automatically enabled when the Core Isolation and Memory Integration features are switched on. As you can tell from the feature name itself, along side it Channel Mitigation is really a security feature that stops any malicious apps or processes from performing Side Channel attacks to access and read data from the host kernel, memory, along with other sensitive parts. Unlike regular attacks, Side Channel attacks are sophisticated and difficult to detect.

The downside from it is that when the Side Channel Mitigation feature is enabled, the performance from the VM drops significantly. As such, VMware shows a warning message suggesting that you ought to disable the Side Channel Mitigation feature to improve the virtual machine performance.

If you want to squeeze a little more performance from your virtual machine, you need to disable along side it Channel Mitigation feature. Within this simple and quick guide, allow me to demonstrate the steps to disable along side it Channel Mitigation feature in VMware Workstation.

Important note: Before proceeding, make sure the target virtual machine is completely powered OFF. If the VM is in paused state, you cannot alter the Side Channel Mitigation setting.

Disable Side Channel Mitigation in VMware

To disable the Side Channel Mitigation in VMware Workstation, stick to the steps given below.

1. First, open the VMware application. It can be done in Windows by looking it up within the Start menu. If the VMware Workstation is pinned for your taskbar, you can click on that too.

2. After opening the VMware application, right-click on the VM for which you want to disable the Side Channel Mitigation and choose the "Settings" option. As I said earlier, the VM ought to be powered OFF completely.

3. Visit the "Options" tab within the VMware Settings window. This is where you will find all of the additional settings associated with your virtual machine.

4. Select the "Advanced" option on the sidebar. Because the name implies, this is when you discover all the advanced settings to customize and better manage your virtual machine.

5. Select the "Disable side channel mitigation for Hyper-V enabled hosts" checkbox.

6. Click the "Ok" button at the bottom of the Settings window.

7. Finally, close and re-open VMware Workstation to fully apply the changes.

That's it. With this, you've disabled the side channel mitigation for any virtual machine on VMware Workstation. In the future, providing begin to see the side-channel mitigation message whenever you switch on the virtual machine. For those who have multiple virtual machines, you may have to do this for anyone VMs individually.

To enable the side-channel mitigation feature, UNCHECK the "Disable side channel mitigation for Hyper-V enabled hosts" checkbox under "VM → Settings → Options → Advanced".

FAQ

Can one disable side channel mitigation in VMware Player?
No, you can't. The choice is only available for VMware Workstation and VMware Fusion. That said, you can still try to disable Memory Integrity and Core Isolation features in Windows 10. Doing this should work for VMware player.

Is changing side channel mitigation settings in VMware safe?
Side channel mitigation is really a security feature. Disabling it'll lower the safety for both host and guest machines. As a result, it's important for you to determine if you are willing to sacrifice a little bit of security for better performance. Generally, if you're following the best practices of using a pc and taking advantage of a good antivirus software, there shouldn't be considered a problem in most cases.

Can one enable the side channel mitigation feature in VMware later on?
Yes, you can. Just UNCHECK the "Disable side channel mitigation for Hyper-V enabled hosts" checkbox under "VM → Settings → Options → Advanced" and you're simply good to go.