VMCS
VMCS stands for Virtual Machine Control Structure. It is a data structure used by Intel's virtualization technology (VMX) to manage transitions between a guest operating system (the virtual machine) and the hypervisor or host. The VMCS stores both the state of the guest and the state to be loaded on exit, along with a set of control fields that govern how VM entries and exits occur. Each logical processor that runs a virtual machine maintains its own VMCS.
A VMCS resides in memory as a region with a VMCS revision identifier and a collection of
Operations with VMCS typically involve the VMX instructions VMXON/VMXOFF to enable or disable VMX operation, VMCS