Client Hyper-V memory reservation on the root partition

Enabling Client Hyper-V on Windows 8 Pro or Enterprise causes the type-1 hypervisor to load during the boot process. This architecture results in the system reserving a specific portion of physical RAM for the root partition to manage virtualization tasks, regardless of whether any virtual machines are actively running.

The amount of memory available to the host operating system is reduced once the hypervisor is active. While hardware requirements like Second Level Address Translation (SLAT) are met for functionality, the specific overhead consumed by the root partition remains a fixed behavior in standard configurations.

Is there a documented configuration or registry setting to limit the amount of RAM reserved by the Hyper-V root partition? Can the hypervisor be forced to release memory to the host when no guest instances are active?