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Microsoft Specific

This topic is new for Visual Studio 2005 SP1.

Activates virtual machine extensions (VMX) operation in the processor.

unsigned char __vmx_on(
      unsigned __int64 *VmsSupportPhysicalAddress


[in] VmsSupportPhysicalAddress

A pointer to a 64-bit physical address that points to a virtual-machine control structure (VMCS).

Value Meaning


The operation succeeded.


The operation failed with extended status available in the VM-instruction error field of the current VMCS.


The operation failed without status available.

The __vmx_on function corresponds to the VMXON 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.

Intrinsic Architecture



Header file <intrin.h>

END Microsoft Specific