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如何进入VMX(Intel) [复制链接]

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离线天道酬勤
 

只看楼主 倒序阅读 使用道具 楼主  发表于: 2016-02-04
— 本帖被 天道酬勤 从 驱动保护 移动到本区(2016-05-19) —
1、检测你的CPU是否支持VMX
MOV EAX,1
CPUID
检测ECX的第5位,如果为1则支持VMX
2、初始化VMXON region
pVMXONRegion = MmAllocateNonCachedMemory( 4096 );
RtlZeroMemory( pVMXONRegion, 4096 );
PHYSICAL_ADDRESS       PhysicalVMXONRegionPtr=MmGetPhysicalAddress( pVMXONRegion );
__asm
{
MOV             ECX, IA32_VMX_BASIC_MSR_CODE //0x480
RDMSR
LEA              EBX, vmxBasicMsr
MOV             [EBX+4], EDX
MOV             [EBX], EAX
}
*(pVMXONRegion) = vmxBasicMsr.RevId;
3、设置VMXE位(CR4)
CR4_REG                                         cr4_reg = {0};
__asm
{
PUSH     EAX
_emit      0x0F       // MOV   EAX, CR4
_emit      0x20
_emit      0xE0
MOV             cr4_reg, EAX
POP        EAX
}
cr4_reg.VMXE = 1;
__asm
{
PUSH     EAX
MOV             EAX, cr4_reg
_emit      0x0F       // MOV   CR4, EAX
_emit      0x22
_emit      0xE0
POP        EAX
}
4、执行VMXON指令
__asm
{
PUSH     DWORD PTR PhysicalVMXONRegionPtr.HighPart
PUSH     DWORD PTR PhysicalVMXONRegionPtr.LowPart
_emit      0xF3       // VMXON [ESP]
_emit      0x0F
_emit      0xC7
_emit      0x34
_emit      0x24
PUSHFD
POP        eFlags
ADD              ESP, 8
}
if( eFlags.CF == 1 )
{
Log( "ERROR : VMXON operation failed." , 0 );
return 0;
}
//到这里说明已经进入了VMX模式,并且工作在ROOT下了

5、初始化VMCS region
//这是个4K大小的内存块
ULONG *pVMCSRegion = MmAllocateNonCachedMemory( 4096 );
RtlZeroMemory( pVMCSRegion, 4096 );
PHYSICAL_ADDRESS  PhysicalVMCSRegionPtr = MmGetPhysicalAddress( pVMCSRegion );
*(pVMCSRegion) = vmxBasicMsr.RevId;
__asm
{
PUSH     DWORD PTR PhysicalVMCSRegionPtr.HighPart
PUSH     DWORD PTR PhysicalVMCSRegionPtr.LowPart
_emit      0x66       // VMCLEAR [ESP]
_emit      0x0F
_emit      0xc7
_emit      0x34
_emit      0x24
ADD       ESP, 8
PUSHFD
POP        eFlags
}
if( eFlags.CF != 0 || eFlags.ZF != 0 )
{
Log( "ERROR : VMCLEAR operation failed." , 0 );
return 0;
}
//到这里,说明VMCS region初始化完成了
6、装载VMCS region
__asm
{
PUSH     DWORD PTR PhysicalVMCSRegionPtr.HighPart
PUSH     DWORD PTR PhysicalVMCSRegionPtr.LowPart
_emit      0x0F       // VMPTRLD [ESP]
_emit      0xC7
_emit      0x34
_emit      0x24
ADD       ESP, 8
}
7、设置VMCS region中的相关域
这些域包括:
A、Guest的各个段寄存器的selector,base,limit,access right
B、Host的各个段寄存器的selector,base,limit,access right
C、Guest的CR0,CR3,CR4,IDTR,GDTR,LDTR,Rflag,SYSENTER_CS,SYSENTER_EIP,SYSENTER_ESP
D、Host的CR0,CR3,CR4,IDTR,GDTR,LDTR,Rflag,SYSENTER_CS,SYSENTER_EIP,SYSENTER_ESP
如:
USHORT    seg_selector = 0;
__asm  MOV      seg_selector, ES
Log( "Setting Guest ES Selector" , seg_selector );
WriteVMCS( 0x00000800, seg_selector );
//Guest CS selector                                                             00000802H
__asm  MOV      seg_selector, CS
Log( "Setting Guest CS Selector" , seg_selector );
WriteVMCS( 0x00000802, seg_selector );

E、Exception bitmap
作为调试器,我们需要拦截INT1和INT3中断,因此,Exception bitmap起码要这样设置:
ULONG        temp32 = 0x00000000;
SetBit( &temp32, 1 );                                              // Single Step (INT 1) int1
SetBit( &temp32, 3 );                                              // Software Interrupt (INT 3)
WriteVMCS( 0x00004004, temp32 );
F、VMX Abort Error Code域
这个域需要清成0
RtlZeroMemory( (pVMCSRegion + 4), 4 );
G、Guest的ESP和EIP
WriteVMCS( 0x0000681C, (ULONG)GuestStack );
WriteVMCS( 0x0000681E, (ULONG)GuestReturn );
H、Host的ESP和EIP
PVOID   HostStack = ExAllocatePoolWithTag( NonPagedPool , 0x8000, 'kSkF' );
If(HostStack == NULL)
{
//…出错…
}
WriteVMCS( 0x00006C14, ((ULONG)HostStack + 0x7FFF) );
WriteVMCS( 0x00006C16, (ULONG)VMExitProc );// VMExitProc就是VMM的程序入口
8、执行VMLAUNCH
__asm
{
_emit      0x0F       // VMLAUNCH
_emit      0x01
_emit      0xC2
}

// 如果成功,就不会到这里了!
__asm
{
PUSHFD
POP        eFlags
}
Log( "VMLAUNCH Failure" , 0xDEADDEAD );
if( eFlags.CF != 0 || eFlags.ZF != 0 || TRUE )
{
ULONG  ErrorCode= VMRead_ULONG(0x00004400);
Log( "VM Instruction Error" , ErrorCode );
}



VMMExitProc

extern "C"
__declspec( naked ) VOID VMMExitProc( )
{
__asm CLI
__asm PUSHAD

  //保存通用寄存器
__asm MOV GuestEAX, EAX
__asm MOV GuestEBX, EBX
__asm MOV GuestECX, ECX
__asm MOV GuestEDX, EDX
__asm MOV GuestEDI, EDI
__asm MOV GuestESI, ESI
__asm MOV GuestEBP, EBP

  //保存调试寄存器
__asm
{
push eax
mov eax,dr0
mov GuestDr0,eax
mov eax,dr1
mov GuestDr1,eax
mov eax,dr2
mov GuestDr2,eax
mov eax,dr3
mov GuestDr3,eax
mov eax,dr6
mov GuestDr6,eax
pop eax
}
GuestDr7 = VMRead_ULONG(VMX_VMCS_GUEST_DR7);//0x681A

  GuestEIP = VMRead_ULONG(VMX_VMCS_GUEST_RIP);//0x681E
GuestEFlags = VMRead_ULONG(VMX_VMCS_GUEST_RFLAGS);//0x6820

//获取本次Exit的详细信息
ULONG ExitReason = VMRead_ULONG(VMX_VMCS_RO_EXIT_REASON);//0x4402
ULONG ExitInterruptionInformation = VMRead_ULONG(VMX_VMCS_RO_EXIT_INTERRUPTION_INFO);//0x4404
ULONG ExitInstructionLength = VMRead_ULONG(VMX_VMCS_RO_EXIT_INSTR_LENGTH);//0x440C
ULONG ExitQualification = VMRead_ULONG(VMX_VMCS_RO_EXIT_QUALIFICATION);//0x6400

  if(ExitReason==0)//是个Exception
{
int IntrNo = ExitInterruptionInformation & 0xFF;
if(IntrNo==1 || IntrNo==3)//是INT1或者INT3
{
if(IsMyBreakPoint())
{//是我们自己设置的断点
DoSomeThing();
}
else
{//我们该向Guest注入一个异常,让Guest的中断处理程序能够继续处理,仿佛一切都没发生
ULONG InjectIrqInfo = 0x80000300 | IntrNo;
// 设置 VM-Entry Exception域
WriteVMCS( VMX_VMCS_CTRL_ENTRY_INSTR_LENGTH, ExitInstructionLength);
WriteVMCS( VMX_VMCS_CTRL_ENTRY_IRQ_INFO, InjectIrqInfo);
}
}
}
if(ExitReason==0x12)//VMMCALL
{//我们用一个VMMCALL指令来通知VMM结束VMX
if(GuestEAX == 0x12345678)//我们自己约定的规则
{
GuestEIP += ExitInstructionLength;
goto Exit;
}
}
goto Resume;
Exit:
//  关闭VMX.
DbgPrint("Terminating VMX Mode.");
__asm
{
_emit 0x0F  // VMXOFF
_emit 0x01
_emit 0xC4
POPAD
MOV   ESP, GuestESP
STI
JMP   GuestEIP
}

  Resume:    
//  Need to execute the VMRESUME without having changed
//  the state of the GPR and ESP et cetera.
__asm
{
push      eax
mov       eax,GuestDr0
mov       DR0,eax
mov       eax,GuestDr1
mov       DR1,eax
mov       eax,GuestDr2
mov       DR2,eax
mov       eax,GuestDr3
mov       DR3,eax
mov       eax,GuestDr6
mov       DR6,eax
pop       eax
POPAD
MOV   EAX, GuestEAX
MOV   EBX, GuestEBX
MOV   ECX, GuestECX
MOV   EDX, GuestEDX
MOV   ESI, GuestESI
MOV   EDI, GuestEDI
MOV   EBP, GuestEBP
STI
_emit 0x0F  // VMRESUME
_emit 0x01
_emit 0xC3

//永远不会到这里
}  

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只看该作者 沙发  发表于: 2016-04-30
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