Use high resolution timer API (ExXXXTimer) to implement LAPIC timer.

This is to replace the regular Windows KeXXXTimer API, which suffered
from insufficient timer resolution and led to LAPIC timer calibration
failure when calibrating against the legacy IRQ0 timer.

However, according to Microfost online documentation here:
https://learn.microsoft.com/en-us/windows-hardware/drivers/kernel/high-resolution-timers
Using newer timer APIs does make the AEHD driver not compatible with
Windows 7 any more. But Microsoft has already removed signing support
for Windows 7 anyway.

Change-Id: If58dc6b984d6eb3c8c330dd66522c9481de55ca7

Author: Taogle2018

aehd/aehd.vcxproj

@@ -22,24 +22,24 @@
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.Default.props" />
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|x64'" Label="Configuration">
-    <TargetVersion>Windows7</TargetVersion>
+    <TargetVersion>WindowsV6.3</TargetVersion>
     <UseDebugLibraries>true</UseDebugLibraries>
     <PlatformToolset>WindowsKernelModeDriver10.0</PlatformToolset>
     <ConfigurationType>Driver</ConfigurationType>
     <DriverType>WDM</DriverType>
     <SpectreMitigation>false</SpectreMitigation>
     <DriverTargetPlatform>Desktop</DriverTargetPlatform>
-    <_NT_TARGET_VERSION>0x0601</_NT_TARGET_VERSION>
+    <_NT_TARGET_VERSION>0x0603</_NT_TARGET_VERSION>
   </PropertyGroup>
   <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|x64'" Label="Configuration">
-    <TargetVersion>Windows7</TargetVersion>
+    <TargetVersion>WindowsV6.3</TargetVersion>
     <UseDebugLibraries>false</UseDebugLibraries>
     <PlatformToolset>WindowsKernelModeDriver10.0</PlatformToolset>
     <ConfigurationType>Driver</ConfigurationType>
     <DriverType>WDM</DriverType>
     <SpectreMitigation>false</SpectreMitigation>
     <DriverTargetPlatform>Desktop</DriverTargetPlatform>
-    <_NT_TARGET_VERSION>0x0601</_NT_TARGET_VERSION>
+    <_NT_TARGET_VERSION>0x0603</_NT_TARGET_VERSION>
   </PropertyGroup>
   <Import Project="$(VCTargetsPath)\Microsoft.Cpp.props" />
   <ImportGroup Label="PropertySheets">

arch/x86/kvm/lapic.c

@@ -1450,6 +1450,7 @@ void kvm_free_lapic(struct kvm_vcpu *vcpu)
 		return;
 
 	hrtimer_cancel(&apic->lapic_timer.timer);
+	hrtimer_delete(&apic->lapic_timer.timer);
 
 	if (apic->regs)
 		free_page((size_t)apic->regs);
@@ -1670,8 +1671,9 @@ int kvm_create_lapic(struct kvm_vcpu *vcpu)
 	}
 	apic->vcpu = vcpu;
 
-	hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC,
-		     HRTIMER_MODE_ABS_PINNED);
+	if (hrtimer_init(&apic->lapic_timer.timer, CLOCK_MONOTONIC,
+		     HRTIMER_MODE_ABS_PINNED))
+		goto nomem_free_apic;
 	apic->lapic_timer.timer.function = apic_timer_fn;
 
 	/*

ntkrutils.c

@@ -129,54 +129,74 @@ NTSTATUS aehdGetCpuOnlineMap(void)
 /*
  Timer Stuffs
  */
-void timer_dpc_fn(struct _KDPC *Dpc, 
-			PVOID DeferredContext, 
-			PVOID SystemArgument1, 
-			PVOID SystemArgument2)
+void timer_callback_fn(PEX_TIMER ex_timer, PVOID ex_timer_context)
 {
-	struct hrtimer *timer = (struct hrtimer*)DeferredContext;
+	struct hrtimer *timer = (struct hrtimer*)ex_timer_context;
 	enum hrtimer_restart ret = timer->function(timer);
 	if(ret == HRTIMER_RESTART)
 		hrtimer_restart(timer);
 }
 
-void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, enum hrtimer_mode mode)
+int hrtimer_init(struct hrtimer *timer, clockid_t clock_id, enum hrtimer_mode mode)
 {
-	KeInitializeTimerEx(&timer->ktimer, SynchronizationTimer);
+	timer->ex_timer = ExAllocateTimer(timer_callback_fn, timer, EX_TIMER_HIGH_RESOLUTION);
+	if (!timer->ex_timer)
+		return 1;
+	ExInitializeSetTimerParameters(&timer->ext_set_parameters);
 	timer->base = &timer->base_hack;
 	timer->base->get_time = ktime_get;
-	KeInitializeThreadedDpc(&timer->kdpc, (PKDEFERRED_ROUTINE)timer_dpc_fn, timer);
+	return 0;
 }
 
 int hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode)
 {
 	int r;
+	LARGE_INTEGER time;
+	LONGLONG duetime;
 	// We only emulate hrtimer mode that KVM uses
 	ASSERTMSG("Unsupported hrtimer mode", mode == HRTIMER_MODE_ABS_PINNED);
 	timer->due_time.QuadPart = ktime_to_ns(tim);
 	timer->node.expires = tim;
 	do_div(&(u64)timer->due_time.QuadPart, 100);
-	r = (int)KeSetTimer(&timer->ktimer, timer->due_time, &timer->kdpc);
+	KeQuerySystemTime(&time);
+	duetime = timer->due_time.QuadPart - time.QuadPart;
+	if (duetime < 0)
+		duetime = 0;
+	r = (int)ExSetTimer(timer->ex_timer, -duetime, 0, &timer->ext_set_parameters);
 	return r;
 }
 
 int hrtimer_cancel(struct hrtimer *timer)
 {
 	int r;
-	r = KeCancelTimer(&timer->ktimer);
+	r = ExCancelTimer(timer->ex_timer, NULL);
 	return r;
 }
 
 int hrtimer_restart(struct hrtimer* timer)
 {
 	int r;
-	//timer->due_time.QuadPart = (ktime_to_ns(ktime_get()) - ktime_to_ns(timer->node.expires)) / 100;
+	LARGE_INTEGER time;
+	LONGLONG duetime;
+
 	timer->due_time.QuadPart = ktime_to_ns(timer->node.expires);
 	do_div(&(u64)timer->due_time.QuadPart, 100);
-	r = (int)KeSetTimer(&timer->ktimer, timer->due_time, &timer->kdpc);
+	KeQuerySystemTime(&time);
+	duetime = timer->due_time.QuadPart - time.QuadPart;
+	if (duetime < 0)
+		duetime = 0;
+	r = (int)ExSetTimer(timer->ex_timer, -duetime, 0, &timer->ext_set_parameters);
 	return r;
 }
 
+void hrtimer_delete(struct hrtimer* timer)
+{
+	EXT_DELETE_PARAMETERS ext_delete_parameters;
+
+	ExInitializeDeleteTimerParameters(&ext_delete_parameters);
+	ExDeleteTimer(timer->ex_timer, TRUE, TRUE, &ext_delete_parameters);
+}
+
 struct list_head aehd_mmap_list;
 DEFINE_RAW_SPINLOCK(aehd_mmap_lock);
 

ntkrutils.h

@@ -596,16 +596,17 @@ struct hrtimer
 	enum hrtimer_restart		(*function)(struct hrtimer *);
 	struct hrtimer_clock_base	*base;
 	size_t			state;
-	KTIMER                  ktimer;
-	KDPC                    kdpc;
+	PEX_TIMER               ex_timer;
+	EXT_SET_PARAMETERS      ext_set_parameters;
 	LARGE_INTEGER           due_time;
 	struct hrtimer_clock_base	base_hack;
 };
 
-void hrtimer_init(struct hrtimer *timer, clockid_t clock_id, enum hrtimer_mode mode);
+int hrtimer_init(struct hrtimer *timer, clockid_t clock_id, enum hrtimer_mode mode);
 int hrtimer_start(struct hrtimer *timer, ktime_t tim, const enum hrtimer_mode mode);
 int hrtimer_cancel(struct hrtimer *timer);
 int hrtimer_restart(struct hrtimer* timer);
+void hrtimer_delete(struct hrtimer* timer);
 
 static __forceinline void hrtimer_add_expires_ns(struct hrtimer *timer, u64 delta)
 {