source: vbox/trunk/src/VBox/Runtime/common/asm/ASMSerializeInstruction-cpuid.asm@ 67979

; $Id: ASMSerializeInstruction-cpuid.asm 59530 2016-01-31 11:56:48Z vboxsync $
;; @file
; IPRT - ASMSerializeInstruction() using cpuid.
;

;
; Copyright (C) 2006-2016 Oracle Corporation
;
; This file is part of VirtualBox Open Source Edition (OSE), as
; available from http://www.virtualbox.org. This file is free software;
; you can redistribute it and/or modify it under the terms of the GNU
; General Public License (GPL) as published by the Free Software
; Foundation, in version 2 as it comes in the "COPYING" file of the
; VirtualBox OSE distribution. VirtualBox OSE is distributed in the
; hope that it will be useful, but WITHOUT ANY WARRANTY of any kind.
;
; The contents of this file may alternatively be used under the terms
; of the Common Development and Distribution License Version 1.0
; (CDDL) only, as it comes in the "COPYING.CDDL" file of the
; VirtualBox OSE distribution, in which case the provisions of the
; CDDL are applicable instead of those of the GPL.
;
; You may elect to license modified versions of this file under the
; terms and conditions of either the GPL or the CDDL or both.
;


;*******************************************************************************
;* Header Files                                                                *
;*******************************************************************************
%include "iprt/asmdefs.mac"

BEGINCODE


;;
; Executes a seralizing instruction.
;
; The CPUID instruction isn't fast or slow, but it always triggers a VM EXIT in
; a virtualized environment, which is prohibitively expensive.
;
BEGINPROC_EXPORTED ASMSerializeInstructionCpuId
        push    xBX
        xor     eax, eax
        cpuid
        pop     xBX
        ret
ENDPROC            ASMSerializeInstructionCpuId