Windows Server 2022: Windows 11 VM w/ nested virtualization failed to start DDA passed-through devices

Question

Configurations:

1. Windows Server 2022 host
2. Windows 11 guest with Nvidia Quadro GP100 passed through via DDA (Discreet Device Assignment)
3. Enable nested virtualization on the Windows 11 VM

Result: all of the passed through devices (e.g. Quadro GP100) failed to start. Device Manager showing exclaiming marks on all these devices. The error is about Windows cannot assign sufficient resources to these devices so they cannot be started.

Workaround: disable nested virtualization, the VM can start properly with all passed through devices working.

Question: can someone confirm the compatibility of DDA and nested virtualization? I cannot find any reliable answers anywhere, so I presume this is a supported case. If it is supported, can someone please suggest a working configuration?

Thanks!
Chris

Answer 1

Hello @Chris Har

As specified in https://learn.microsoft.com/en-us/windows-server/virtualization/hyper-v/deploy/deploying-graphics-devices-using-dda , DDA is compatible to share PCI devices with VMs but Microsoft provides no specifics into nested virtualization compatibility. Neither compatible or incompatible, but the absence of defined approach may seem that it has an unconsistent experience.

In theory, it should work, as long as the PCIe is passed through DDA, enabling DDA on the Virtual Machine should also pass the hardware to the nested virtual system.

Hope this helps with your query,

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