Guest operating system on hypervisor receives the available features and capabilities of the virtual CPU from the hypervisor.
Configuring the hypervisor to restrict CPU capabilities for guest operating system with
limited instruction sets means that your guest operating system only uses the sets that the hardware CPU provided.
Microsoft Hyper-V offers processor compatibility mode for live migration. When the processor compatibility mode is enabled, the Hyper-V hypervisor restricts many advanced CPU capabilities for vATD use. Because vATD transparently passes through the available CPU capabilities from hypervisor to sandbox VM, the sandbox VM on vATD only receives the restricted instruction sets.
If binary code in the sandbox VM happens to call an instruction that virtual CPU does not support, the software crashes.