Hi 李永钢,
To prevent exhausting your limited key activations, Microsoft designed Automatic Virtual Machine Activation for environments where the physical host is running a properly licensed Windows Server Datacenter edition. This feature allows the guest virtual machines to activate directly against the host machine without ever needing internet access or consuming your standard key counts. You can implement this by opening an administrative command prompt inside the guest virtual machine and utilizing the software licensing management tool. You simply execute slmgr.vbs /ipk followed by the official AVMA client key published by Microsoft for your specific Windows Server version. This generic key is installed, the virtual machine handles its licensing status internally by communicating with the host through the Hyper-V Data Exchange service.
Hope this answer brought you some useful information. If it did, please hit “accept answer”. Thank you :)
Domic V.