VirtualBox VS. Hardware Breakpoints

//http://waleedassar.blogspot.com (@waleedassar)
// Code to test whether VirtualBox (With VTX/AMD-V turned off) supports hardware breakpoints
#include "stdafx.h"
#include <stdio.h>
#include <windows.h>

#define CONTEXT_ALL 0x1003F;

unsigned char probe=0x100;

int __cdecl Handler(EXCEPTION_RECORD* pRec,void* est,unsigned char* pContext,void* disp)
{
    if(pRec->ExceptionCode==0xC0000005)
    {
        *(unsigned long*)pContext=CONTEXT_ALL;
        //Set debug registers here
        *(unsigned long*)(pContext+0x4)=(unsigned long)(&probe);
        *(unsigned long*)(pContext+0x18)=0x032101;
        (*(unsigned long*)(pContext+0xB8))+=0x6;
        return ExceptionContinueExecution;
    }
    if(pRec->ExceptionCode==EXCEPTION_SINGLE_STEP)
    {
        MessageBox(0,"Expected behavior","waliedassar",0);
        ExitProcess(0);
    }
    return ExceptionContinueSearch;
}

int main()
{
    __asm
    {
        push offset Handler
        push dword ptr fs:[0x0]
        mov dword ptr fs:[0x0],esp
        xor eax,eax
        mov dword ptr[eax],0x1  ;;triggers an AV
        nop
        nop
        nop
        nop
        nop
    }
    unsigned char x=probe;
    MessageBox(0,"VirtualBox(Intel-VTX/AMD-V Turned off) detected","waliedassar",0);
    return 0;
}