From bdb267e42b08dd187ce66cf4b4400a73fe45dfbc Mon Sep 17 00:00:00 2001
From: lhodges1 <lachiehodges7785@gmail.com>
Date: Mon, 21 Aug 2023 22:40:40 +1000
Subject: [PATCH] e

---
 driver/driver.c               |  3 +++
 driver/driver.vcxproj         |  2 ++
 driver/driver.vcxproj.filters |  6 +++++
 driver/hv.c                   | 43 +++++++++++++++++++++++++++++++++++
 driver/hv.h                   |  8 +++++++
 driver/ioctl.c                |  6 +++--
 6 files changed, 66 insertions(+), 2 deletions(-)
 create mode 100644 driver/hv.c
 create mode 100644 driver/hv.h

diff --git a/driver/driver.c b/driver/driver.c
index 278b7fd..39cedd4 100644
--- a/driver/driver.c
+++ b/driver/driver.c
@@ -4,6 +4,9 @@
 #include "ioctl.h"
 #include "callbacks.h"
 
+#include "hv.h"
+
+
 PVOID callback_registration_handle;
 
 LONG protected_process_id;
diff --git a/driver/driver.vcxproj b/driver/driver.vcxproj
index 791c378..4ccb1fc 100644
--- a/driver/driver.vcxproj
+++ b/driver/driver.vcxproj
@@ -127,6 +127,7 @@
   <ItemGroup>
     <ClCompile Include="callbacks.c" />
     <ClCompile Include="driver.c" />
+    <ClCompile Include="hv.c" />
     <ClCompile Include="ioctl.c" />
     <ClCompile Include="modules.c" />
     <ClCompile Include="nmi.c" />
@@ -136,6 +137,7 @@
     <ClInclude Include="callbacks.h" />
     <ClInclude Include="common.h" />
     <ClInclude Include="driver.h" />
+    <ClInclude Include="hv.h" />
     <ClInclude Include="ioctl.h" />
     <ClInclude Include="modules.h" />
     <ClInclude Include="nmi.h" />
diff --git a/driver/driver.vcxproj.filters b/driver/driver.vcxproj.filters
index 0d49a77..1cc244a 100644
--- a/driver/driver.vcxproj.filters
+++ b/driver/driver.vcxproj.filters
@@ -42,6 +42,9 @@
     <ClCompile Include="queue.c">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="hv.c">
+      <Filter>Source Files</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="driver.h">
@@ -65,5 +68,8 @@
     <ClInclude Include="queue.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="hv.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/driver/hv.c b/driver/hv.c
new file mode 100644
index 0000000..793662a
--- /dev/null
+++ b/driver/hv.c
@@ -0,0 +1,43 @@
+#include "hv.h"
+
+#include <intrin.h>
+
+#include "common.h"
+
+#define TOTAL_ITERATION_COUNT 20
+
+#define IA32_APERF_MSR 0x000000E8
+
+/*
+* 1. Bind thread to a single core
+* 2. Raise the IRQL to HIGH_LEVEL
+* 3. disable interrupts 
+*/
+VOID APERFMsrTimingCheck()
+{
+	ULONG64 old_irql;
+	INT cpuid_result[ 4 ];
+
+	old_irql = __readcr8();
+
+	__writecr8( HIGH_LEVEL );
+
+	_disable();
+
+	UINT64 aperf_before = __readmsr( IA32_APERF_MSR ) << 32;
+
+	__cpuid( cpuid_result, 1 );
+
+	UINT64 aperf_after = __readmsr( IA32_APERF_MSR ) << 32;
+
+	_enable();
+
+	__writecr8( old_irql );
+
+	UINT64 aperf_delta = aperf_after - aperf_before;
+
+	_enable();
+
+	DEBUG_LOG( "delta: %llx", aperf_delta );
+
+}
\ No newline at end of file
diff --git a/driver/hv.h b/driver/hv.h
new file mode 100644
index 0000000..e30ae70
--- /dev/null
+++ b/driver/hv.h
@@ -0,0 +1,8 @@
+#ifndef HV_H
+#define HV_H
+
+#include <ntifs.h>
+
+VOID APERFMsrTimingCheck();
+
+#endif
\ No newline at end of file
diff --git a/driver/ioctl.c b/driver/ioctl.c
index f1fa2bb..86bd574 100644
--- a/driver/ioctl.c
+++ b/driver/ioctl.c
@@ -7,6 +7,8 @@
 #include "driver.h"
 #include "callbacks.h"
 
+#include "hv.h"
+
 NTSTATUS DeviceControl(
 	_In_ PDRIVER_OBJECT DriverObject,
 	_In_ PIRP Irp
@@ -40,8 +42,6 @@ NTSTATUS DeviceControl(
 		* it will issue a bug check under windows driver verifier.
 		*/
 
-		DEBUG_LOG( "irp addr: %p", ( void* )Irp );
-
 		status = PsCreateSystemThread(
 			&handle,
 			PROCESS_ALL_ACCESS,
@@ -98,6 +98,8 @@ NTSTATUS DeviceControl(
 
 	case IOCTL_HANDLE_REPORTS_IN_CALLBACK_QUEUE:
 
+		APERFMsrTimingCheck();
+
 		status = HandlePeriodicCallbackReportQueue(Irp);
 
 		if ( !NT_SUCCESS( status ) )