hook_msr.h File Reference

#include "introtypes.h"

Go to the source code of this file.

Data Structures
struct	_MSR_HOOK_STATE
struct	_HOOK_MSR

Typedefs
typedef INTSTATUS(*	PFUNC_MsrReadWriteHookCallback) (DWORD Msr, DWORD Flags, INTRO_ACTION *Action, void *Context, QWORD OriginalValue, QWORD *NewValue)
	Model specific register access callback. More...
typedef struct _MSR_HOOK_STATE	MSR_HOOK_STATE
typedef struct _MSR_HOOK_STATE *	PMSR_HOOK_STATE
typedef struct _HOOK_MSR	HOOK_MSR
typedef struct _HOOK_MSR *	PHOOK_MSR

Functions
INTSTATUS	IntHookMsrSetHook (DWORD Msr, DWORD Flags, PFUNC_MsrReadWriteHookCallback Callback, void *Context, void **Hook)
	Set a model-specific register write hook. More...
INTSTATUS	IntHookMsrRemoveHook (HOOK_MSR *Hook)
	Remove a model specific register hook. More...
INTSTATUS	IntHookMsrCommit (void)
	Commit the model specific register hooks. More...
INTSTATUS	IntHookMsrInit (void)
	Initialize the model specific registers hook state. More...
INTSTATUS	IntHookMsrUninit (void)
	Uninit the model specific register hooks state. More...

Typedef Documentation

HOOK_MSR

typedef struct _HOOK_MSR HOOK_MSR

Describes a MSR hook.

MSR_HOOK_STATE

typedef struct _MSR_HOOK_STATE MSR_HOOK_STATE

Global MSR hooks state.

PFUNC_MsrReadWriteHookCallback

typedef INTSTATUS(* PFUNC_MsrReadWriteHookCallback) (DWORD Msr, DWORD Flags, INTRO_ACTION *Action, void *Context, QWORD OriginalValue, QWORD *NewValue)

Model specific register access callback.

Parameters

[in]	Msr	The accessed MSR.
[in]	Flags	Indicates read or write access. See IG_MSR_HOOK_TYPE.
[out]	Action	Desired action.
[in]	Context	Optional context, as passed to the hook set function.
[in]	OriginalValue	Original MSR value.
[in,out]	NewValue	New MSR value. Can be overridden, but whether this is handled by the HV or not is implementation specific. It is advisable to not modify this value.

Definition at line 23 of file hook_msr.h.

PHOOK_MSR

typedef struct _HOOK_MSR * PHOOK_MSR

PMSR_HOOK_STATE

typedef struct _MSR_HOOK_STATE * PMSR_HOOK_STATE

Function Documentation

IntHookMsrCommit()

INTSTATUS IntHookMsrCommit

(

void

)

Commit the model specific register hooks.

This function will iterate the list of MSR hooks, and it will delete all the hooks that were flagged for removal.

Return values

INT_STATUS_SUCCESS	On success.
INT_STATUS_NOT_INITIALIZED	If the MSR hooks state is not initialized.

Definition at line 224 of file hook_msr.c.

Referenced by IntGuestPreReturnCallback().

IntHookMsrInit()

INTSTATUS IntHookMsrInit

(

void

)

Initialize the model specific registers hook state.

Return values

INT_STATUS_SUCCESS	On success.
INT_STATUS_INSUFFICIENT_RESOURCES	If a memory alloc fails.

Definition at line 262 of file hook_msr.c.

Referenced by IntGuestInit().

IntHookMsrRemoveHook()

INTSTATUS IntHookMsrRemoveHook

(

HOOK_MSR *

Hook

)

Remove a model specific register hook.

Removes a MSR write hook. First of all, this function will mark the hook as being disabled (the callback will never be called again). If we are currently in the context of a MSR violation, we will wait for the commit phase to permanently delete the hook. Otherwise, the hook will be deleted immediately. NOTE: If this is the last hook set on this particular MSR, VM exits will be disabled on it.

Parameters

[in]

Hook

The hook to be removed.

Return values

INT_STATUS_SUCCESS	On success.
INT_STATUS_INVALID_PARAMETER	If an invalid parameter is supplied.

Definition at line 138 of file hook_msr.c.

Referenced by IntHandleMsrViolation(), IntHookMsrRemoveAllHooks(), and IntMsrSyscallUnprotect().

IntHookMsrSetHook()

INTSTATUS IntHookMsrSetHook	(	DWORD	Msr,
		DWORD	Flags,
		PFUNC_MsrReadWriteHookCallback	Callback,
		void *	Context,
		void **	Hook
	)

Set a model-specific register write hook.

Establishes a hook on the given MSR (Model Specific Register). Flags may indicate whether it is a read, write or both hook. When the first hook is set on a MSR, VM exits are enabled for it. When the first MSR hook is set, the MSR access callback is registered to the HV.

Parameters

[in]	Msr	The MSR to be intercepted.
[in]	Flags	IG_MSR_HOOK_WRITE for write access, IG_MSR_HOOK_READ for read access.
[in]	Callback	The callback to be called when Msr is accessed.
[in]	Context	Optional context, will be passed to the callback on calls.
[in]	Hook	Handle to the newly placed MSR hook.

Return values

INT_STATUS_SUCCESS	On success.
INT_STATUS_INVALID_PARAMETER	If an invalid parameter is supplied.
INT_STATUS_INSUFFICIENT_RESOURCES	If a memory alloc fails.

Definition at line 11 of file hook_msr.c.

Referenced by IntMsrSyscallProtect().

IntHookMsrUninit()

INTSTATUS IntHookMsrUninit

(

void

)

Uninit the model specific register hooks state.

Return values

INT_STATUS_SUCCESS	On success.
INT_STATUS_NOT_INITIALIZED_HINT	If the MSR hooks state is not initialized.

Definition at line 285 of file hook_msr.c.

Referenced by IntGuestUninit().