本文只是學習此視頻後的一些總結 不當之處還請指出
視頻作者:小寶來了
視頻連接:http://bbs.pediy.com/showthread.php?t=211973
約定:
本文中出現的名詞
虛擬機 客戶機 GUEST 都是被監控的操作系統或應用程序
宿主機 HOST Hypervisor都是指監控虛擬機的“原”操作系統
VMM:當客戶機發生退出事件時,進入的就是VMM
VM:當客戶機正常運行時就是VM
VMM監控VM
步驟在Intel手冊35.1章
1.使用CPUID指令查看CPU信息
需要關注的是ECX(RCX)寄存器
這裏只講x86
返回的ecx是一個
typedefunion
{
struct
{
unsigned SSE3:1;
unsigned PCLMULQDQ:1;
unsigned DTES64:1;
unsigned MONITOR:1;
unsigned DS_CPL:1;
unsigned VMX:1;
unsigned SMX:1;
unsigned EIST:1;
unsigned TM2:1;
unsigned SSSE3:1;
unsigned Reserved:22;
};
}_CPUID_ECX;
我們需要判斷其中VMX位是否爲1 是支持VT 否則不支持
2.查看CR0 CR4控制寄存器
CR0寄存器的PE、PG、NE位必須爲1
如果不爲1 則是在BIOS中沒有啓用VT
CR4寄存器的VMXE位是否爲1
如果爲1則說明已經有VT存在了
用到的結構圷:
typedefunion
{
struct
{
unsigned PE:1;
unsigned MP:1;
unsigned EM:1;
unsigned TS:1;
unsigned ET:1;
unsigned NE:1;
unsigned Reserved_1:10;
unsigned WP:1;
unsigned Reserved_2:1;
unsigned AM:1;
unsigned Reserved_3:10;
unsigned NW:1;
unsigned CD:1;
unsigned PG:1;
//unsigned Reserved_64:32;
};
}_CR0;
typedef union
{
struct{
unsigned VME:1;
unsigned PVI:1;
unsigned TSD:1;
unsigned DE:1;
unsigned PSE:1;
unsigned PAE:1;
unsigned MCE:1;
unsigned PGE:1;
unsigned PCE:1;
unsigned OSFXSR:1;
unsigned PSXMMEXCPT:1;
unsigned UNKONOWN_1:1; //These are zero
unsigned UNKONOWN_2:1; //These are zero
unsigned VMXE:1; //It's zero in normal
unsigned Reserved:18; //These are zero
//unsigned Reserved_64:32;
};
}_CR4;
3.檢查MSR寄存器(MSR_IA32_FEATURE_CONTROL)
MSR_IA32_FEATURE_CONTROL的lock位是否爲1
如果不爲1則VT指令沒有開啓無法使用某些VT指令
用到的結構如下:
typedefstruct _IA32_FEATURE_CONTROL_MSR
{
unsigned Lock :1; // Bit 0 is the lock bit - cannotbe modified once lock is set
unsigned Reserved1 :1; //Undefined
unsigned EnableVmxon :1; // Bit 2. Ifthis bit is clear, VMXON causes a general protection exception
unsigned Reserved2 :29; //Undefined
unsigned Reserved3 :32; //Undefined
} IA32_FEATURE_CONTROL_MSR;
代碼如下:
#pragma once
#include <ntddk.h>
#include "vtsystem.h"
#include "vtasm.h"
BOOLEAN bCheckCpuSuppert()
{
//1.執行CPUID
ULONG uRet_Eax, uRet_Ebx, uRet_Ecx , uRet_Edx;
_CR0 cr0;
_CR4 cr4;
_CPUID_ECX uCpuId_Ecx;
IA32_FEATURE_CONTROL_MSR msr;
Asm_CPUID(1, &uRet_Eax, &uRet_Ebx, &uRet_Ecx, &uRet_Edx);
*((PULONG)&uCpuId_Ecx) = uRet_Ecx;
if (uCpuId_Ecx.VMX != 1)
{
DbgPrint("當前CPU不支持VT!\n");
return FALSE;
}
//2.CR0 CR4
cr0 = Asm_GetCr0Ex();
if (cr0.PE != 1 || cr0.PG != 1 || cr0.NE != 1)
{
DbgPrint("請在Bios裏面設置VT選項!\n");
return FALSE;
}
cr4 = Asm_GetCr4Ex();
if (cr4.VMXE == 1)
{
DbgPrint("已經有VT啦!\n");
return FALSE;
}
//3.Msr
Asm_ReadMsrEx(MSR_IA32_FEATURE_CONTROL, (PMSR)&msr);
if (msr.Lock != 1)
{
DbgPrint("VT 指令沒有鎖定!\n");
return FALSE;
}
DbgPrint("當前CPU支持VT!\n");
return TRUE;
}
下一章將講退出事件的分發