VMEXIT instruction information and VMEXIT instruction qualification

[abhijeet_thatte]

Hi,

This is a naive question on my part. I am going through the VT part of the Intel manual. I came across two terms vmexit instruction information and vmexit instruction qualification. I was wondering what is the difference between two types and why these two segmenets were separate in VMCS structure.

Thanks

[David_O_Intel1]

VM-Exit qualification provides general information about conditions causing a VM-Exit (e.g.,faulting address within a page fault), something that maynot be availablefromthe instruction itself.

From the Software Development Manaual 3B, 24.2.1:

"For INVEPT, INVVPID, LGDT, LIDT, LLDT, LTR, SGDT, SIDT, SLDT, STR, VMCLEAR, VMPTRLD, VMPTRST, VMREAD, VMWRITE, and VMXON, the exit qualification receives the value of the instructions displacement field, which is sign-extended to 64 bits if necessary (32 bits on processors that do not support Intel 64 architecture). If the instruction has no displacement (for example, has a register operand), zero is stored into the exit qualification"

VM-Exit information provides exact information about the faulting instruction itself.

Intel 64 and IA-32 Architectures Software Developer's Manuals are at:
http://www.intel.com/products/processor/manuals/

David Ott