I have a virtual PLC which runs using qemu with whpx acceleration. I am looking if it is possible to run this in a cloud environment.

Hi Nagy, Tomas (INNIO),
For more information with Vahid Ghafarpour answer you can check the below link with a similar query
https://learn.microsoft.com/en-us/answers/questions/385506/windows-hypervisor-platform-feature-on-2016
and after setting up the VM, you can enable WHPX by installing the necessary Hyper-V role and ensuring the Windows Hypervisor Platform feature is active.
Hope this information is helpful, please "Upvote" if the information was useful.

Running QEMU with WHPX acceleration in Azure is not supported, even with nested virtualization enabled. WHPX relies on Hyper-V virtualization extensions that are often inaccessible inside nested VMs in Azure.

As per the screenshots you have shared so far, I can see in screenshot 1 that the error says "Hyper-V cannot be installed: Virtualization support is disabled in the firmware"

Reason- The Azure VM does not have nested virtualization enabled, or the VM size does not support it.

In your screenshot 2 and 3 you highlighted that PowerShell shows Hyper-V features are enabled, but the qemu-system-x86_64 fails with error- failed to initialize whpx: No space left on device and Windows Hypervisor Platform is enabled.

But it does not guarantee WHPX will function inside Azure VMs

Why? What are the limitations then?

Azure VMs like Dv3/Ev3 support Hyper-V-based nested virtualization, but the WHPX driver may not initialize correctly inside these VMs because Azure controls the host hypervisor and does not expose all VT-x instructions needed for WHPX to work inside the guest. Please note that Nested VM -> WHPX -> Virtual PLC is a triple-layer virtualization—Azure -> Hyper-V VM -> QEMU with WHPX which is not a supported path.

**
In short-** ctrlX WORKS requires WHPX, but WHPX doesn't work in Azure VMs due to virtualization constraints. Your best bet is to run it on a physical Windows machine.

Reference document

• Hyper V system requirements
• Nested virtualization

QEMU with WHPX is a third-party virtualization application. WHPX specifically requires hardware virtualization extensions like VT-x/EPT. Microsoft explicitly states these are not supported in nested VMs for third-party hypervisors.

I hope I was able give you clarity on whether it is possible to run a Windows VM with WHPX support in Azure. Thanks

Thanks for posting your question in the Microsoft Q&A forum.

Ensure the VM supports nested virtualization, which is required for WHPX (Windows Hypervisor Platform) acceleration. Next, choose a VM size that supports nested virtualization, such as the Dv3 or Ev3 series.

** Please don't forget to close up the thread here by upvoting and accept it as an answer if it is helpful **

Thanks for coming back, unfortunately Dv3 or Ev3 series supports only Hyper-V which is different from what I need.

If I try run qemu with whpx on Hyper-V:

And I would need this:

Is it possible on Azure VM?

Thanks

Hi Nagy, Tomas (INNIO),
We received your feedback of not being satisfied with the information provided.
You can check requirements for enabling Hyper-V. here
you also need to turn on few more features

For setting up nested virtualization and using WHP in Azure, check Generation2 VMs. https://learn.microsoft.com/en-us/azure/virtual-machines/generation-2#generation-2-vm-sizes
And as you said "Dv3 or Ev3 series supports only Hyper-V which is different from what I need", so we would like to know what are your specific requirements, and which virtual PLC you are using so that we can help you further.

Hi,

I only clicked the button that it did not solve my problem. Did not say about not being satisfied.

Unfortunately I do not know now much about nested virtualisation. I am only trying to understand that if it is possible to run qemu with whpx acceleration on a cloud VM.

As shown on the 2nd photo, on a Dv3 with Hyper-V enabled it does not work.

I am trying to run a Virtual PLC from Bosch Rexroth called ctrlX WORKS.

This needs the Windows Hypervisor Platform as shown on my 3rd photo

Dear Tomas,

Thank you for your questions here. at Q&A portal. So, Azure currently supports nested virtualization (including WHPX) on certain VM sizes, such as the Dv3/Esv3 or Dv4/Esv4 series (Intel VT-x) and NVv4 series (AMD SVM). However, WHPX acceleration specifically requires pare example A Windows 10/11 or Windows Server 2019/2022 guest OS. A host VM size that supports nested virtualization (e.g., Esv3).

Deploy a compatible VM (e.g., E4s_v3). Enable Hyper-V and WHPX in the guest OS via PShell

Enable-WindowsOptionalFeature

Configure QEMU/KVM to use WHPX (-accel whpx).

But be ready for some limitations par example as performance may vary based on Azure’s underlying hardware and GPU passthrough is not supported. For detailed steps, try to Microsoft’s nested virtualization documentation.

Best regards,

Alex

P.S. If my answer help to you, please Accept my answer

Thank you for the reply.

It looks like to me the answer is that it is not possible to have whpx support. As I already tried this suggestion and put a screenshot before.

Details:

I have created a VM with a D2s_v3 with Windows (Windows Server 2022 Datacenter Azure Edition).

Installed these:

Hyper-V

Enable-WindowsOptionalFeature -Online -FeatureName Microsoft-Hyper-V -All

Virtual Machine Platform

Enable-WindowsOptionalFeature -Online -FeatureName VirtualMachinePlatform

Windows Hypervisor Platform

Enable-WindowsOptionalFeature -Online -FeatureName HypervisorPlatform

with the following result:

I am not worried about the performance as even running slow would be better than nothing.

But I am afraid this will only run a physical PC.

Thanks

So what are u lose if u will try make a copy of u vm in Azure? Don't del it locally... if something goes wrong u have locally hosted vm

I am not sure what you mean. As I mentioned before I could net qemu running in cloud VM with WHPX acceleration. So I am only able to run it a local PC.