Initializes the specified virtual machine control structure (VMCS) and sets its launch state to Clear.
An application can perform a VM-enter operation by using either the __vmx_vmlaunch or __vmx_vmresume function. The __vmx_vmlaunch function can be used only with a VMCS whose launch state is Clear, and the __vmx_vmresume function can be used only with a VMCS whose launch state is Launched. Consequently, use the __vmx_vmclear function to set the launch state of a VMCS to Clear. Use the __vmx_vmlaunch function for your first VM-enter operation and the __vmx_vmresume function for subsequent VM-enter operations.
The __vmx_vmclear function is equivalent to the VMCLEAR machine instruction. This function supports the interaction of a host's virtual machine monitor with a guest operating system and its applications. For more information, search for the document, "Intel Virtualization Technical Specification for the IA-32 Intel Architecture," document number C97063-002, at the Intel Corporation site.