If 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 by default. This feature is also automatically enabled if the Core Isolation and Memory Integration features are turned on. As you can tell from the feature name itself, the Side Channel Mitigation is a security feature that prevents any malicious apps or processes from performing Side Channel attacks to access and read data from the host kernel, memory, and other sensitive parts. Unlike regular attacks, Side Channel attacks are sophisticated and hard to detect.
The downside of it is that when the Side Channel Mitigation feature is enabled, the performance of the VM drops significantly. As such, VMware shows a warning message telling you that you should disable the Side Channel Mitigation feature to improve the virtual machine performance.
If you want to squeeze a bit more performance out of your virtual machine, you should disable the Side Channel Mitigation feature. In this quick and simple guide, let me show you the steps to disable the Side 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 change the Side Channel Mitigation setting.
Disable Side Channel Mitigation in VMware
To disable the Side Channel Mitigation in VMware Workstation, follow the steps given below.
1. First, open the VMware application. You can do that in Windows by searching for it in the Start menu. If the VMware Workstation is pinned to 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 select the “Settings” option. As I said earlier, the VM should be powered OFF completely.
3. Go to the “Options” tab in the VMware Settings window. This is where you will find all the additional settings related to your virtual machine.
4. Select the “Advanced” option on the sidebar. As the name implies, this is where you find 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 on the “Ok” button at the bottom of the Settings window.
7. Finally, close and re-open VMware Workstation to fully apply the changes.
That is it. With that, you have disabled the side channel mitigation for a virtual machine on VMware Workstation. From now on, you will no longer see the side-channel mitigation message when you turn on the virtual machine. If you have multiple virtual machines, you might have to do this for all those 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”.
No, you cannot. The option is only available for VMware Workstation and VMware Fusion. That being said, you can still try to disable Memory Integrity and Core Isolation features in Windows 10. Doing this should work for VMware player.
Side channel mitigation is a security feature. Disabling it will lower the security for both host and guest machines. As such, it is important for you to decide if you are willing to sacrifice a bit of security for better performance. In general, if you are following the best practices of using a computer and using a good antivirus software, there shouldn’t be a problem in most cases.
Yes, you can. Just UNCHECK the “Disable side channel mitigation for Hyper-V enabled hosts” checkbox under “VM → Settings → Options → Advanced” and you are good to go.
I hope that helps. If you are stuck or need some help, comment below and I will try to help as much as possible.
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