중첩 가상화(Nested Virtualization) - The virtual machine could not be started because this platform does not support nested virtualization.

// VM 이름 testvm이라고 가정

Set-VMProcessor -VMNAME testvm -ExposeVirtualizationExtensions:$True 

An error occurred while attempting to start the selected virtual machine(s).

'testvm' failed to start.

'testvm' could not initialize.

The virtual machine could not be started because this platform does not support nested virtualization.

'testvm' failed to start. (Virtual machine ID B20F20E6-7F19-4796-BA40-D9FFE2D8FE29)

'testvm' failed to start worker process: Unspecified error (0x80004005). (Virtual machine ID B20F20E6-7F19-4796-BA40-D9FFE2D8FE29)

'testvm' could not initialize. (Virtual machine ID B20F20E6-7F19-4796-BA40-D9FFE2D8FE29)

The virtual machine could not be started because this platform does not support nested virtualization. Consider not exposing virtualization extensions to the virtual machine.

Run Hyper-V in a Virtual Machine with Nested Virtualization
; https://docs.microsoft.com/en-us/virtualization/hyper-v-on-windows/user-guide/nested-virtualization

An Intel processor with VT-x and EPT technology -- nesting is currently Intel-only.

AMD Nested Virtualization Support
; https://techcommunity.microsoft.com/t5/virtualization/amd-nested-virtualization-support/ba-p/1434841

Disable check for nested virtualization only working on Intel CPUs 
; https://github.com/GNS3/gns3-server/issues/1777

,.. AMD is now allowed on Windows 10 build 19640 or later. This will work in our next release, version 2.2.10.