The hypervisor manages physical memory utilizing hardware virtualization extensions (Intel VT-x/EPT or AMD-V/NPT). Under HVCI, the hypervisor enforces at the hardware level via Second-Level Address Translation (SLAT).A memory page in the VTL 0 kernel can be writable, or it can be executable, but it can never be both simultaneously.
HVCI operates by creating a secure environment called Virtualization-Based Security (VBS). It utilizes a hypervisor (Hyper-V) to manage memory page permissions: Hvci Bypass