Merge pull request #8549 from liamwhite/kscheduler-sc

kernel: use KScheduler from Mesosphere

src/core/arm/arm_interface.cpp

@@ -154,9 +154,10 @@ void ARM_Interface::Run() {
             break;
         }
 
-        // Handle syscalls and scheduling (this may change the current thread)
+        // Handle syscalls and scheduling (this may change the current thread/core)
         if (Has(hr, svc_call)) {
             Kernel::Svc::Call(system, GetSvcNumber());
+            break;
         }
         if (Has(hr, break_loop) || !uses_wall_clock) {
             break;

src/core/cpu_manager.cpp

@@ -8,6 +8,7 @@
 #include "core/core.h"
 #include "core/core_timing.h"
 #include "core/cpu_manager.h"
+#include "core/hle/kernel/k_interrupt_manager.h"
 #include "core/hle/kernel/k_scheduler.h"
 #include "core/hle/kernel/k_thread.h"
 #include "core/hle/kernel/kernel.h"
@@ -49,14 +50,6 @@ void CpuManager::GuestThreadFunction() {
     }
 }
 
-void CpuManager::GuestRewindFunction() {
-    if (is_multicore) {
-        MultiCoreRunGuestLoop();
-    } else {
-        SingleCoreRunGuestLoop();
-    }
-}
-
 void CpuManager::IdleThreadFunction() {
     if (is_multicore) {
         MultiCoreRunIdleThread();
@@ -69,21 +62,21 @@ void CpuManager::ShutdownThreadFunction() {
     ShutdownThread();
 }
 
+void CpuManager::HandleInterrupt() {
+    auto& kernel = system.Kernel();
+    auto core_index = kernel.CurrentPhysicalCoreIndex();
+
+    Kernel::KInterruptManager::HandleInterrupt(kernel, static_cast<s32>(core_index));
+}
+
 ///////////////////////////////////////////////////////////////////////////////
 ///                             MultiCore                                   ///
 ///////////////////////////////////////////////////////////////////////////////
 
 void CpuManager::MultiCoreRunGuestThread() {
+    // Similar to UserModeThreadStarter in HOS
     auto& kernel = system.Kernel();
     kernel.CurrentScheduler()->OnThreadStart();
-    auto* thread = kernel.CurrentScheduler()->GetSchedulerCurrentThread();
-    auto& host_context = thread->GetHostContext();
-    host_context->SetRewindPoint([this] { GuestRewindFunction(); });
-    MultiCoreRunGuestLoop();
-}
-
-void CpuManager::MultiCoreRunGuestLoop() {
-    auto& kernel = system.Kernel();
 
     while (true) {
         auto* physical_core = &kernel.CurrentPhysicalCore();
@@ -91,18 +84,26 @@ void CpuManager::MultiCoreRunGuestLoop() {
             physical_core->Run();
             physical_core = &kernel.CurrentPhysicalCore();
         }
-        {
-            Kernel::KScopedDisableDispatch dd(kernel);
-            physical_core->ArmInterface().ClearExclusiveState();
-        }
+
+        HandleInterrupt();
     }
 }
 
 void CpuManager::MultiCoreRunIdleThread() {
+    // Not accurate to HOS. Remove this entire method when singlecore is removed.
+    // See notes in KScheduler::ScheduleImpl for more information about why this
+    // is inaccurate.
+
     auto& kernel = system.Kernel();
+    kernel.CurrentScheduler()->OnThreadStart();
+
     while (true) {
-        Kernel::KScopedDisableDispatch dd(kernel);
-        kernel.CurrentPhysicalCore().Idle();
+        auto& physical_core = kernel.CurrentPhysicalCore();
+        if (!physical_core.IsInterrupted()) {
+            physical_core.Idle();
+        }
+
+        HandleInterrupt();
     }
 }
 
@@ -113,80 +114,73 @@ void CpuManager::MultiCoreRunIdleThread() {
 void CpuManager::SingleCoreRunGuestThread() {
     auto& kernel = system.Kernel();
     kernel.CurrentScheduler()->OnThreadStart();
-    auto* thread = kernel.CurrentScheduler()->GetSchedulerCurrentThread();
-    auto& host_context = thread->GetHostContext();
-    host_context->SetRewindPoint([this] { GuestRewindFunction(); });
-    SingleCoreRunGuestLoop();
-}
 
-void CpuManager::SingleCoreRunGuestLoop() {
-    auto& kernel = system.Kernel();
     while (true) {
         auto* physical_core = &kernel.CurrentPhysicalCore();
         if (!physical_core->IsInterrupted()) {
             physical_core->Run();
             physical_core = &kernel.CurrentPhysicalCore();
         }
+
         kernel.SetIsPhantomModeForSingleCore(true);
         system.CoreTiming().Advance();
         kernel.SetIsPhantomModeForSingleCore(false);
-        physical_core->ArmInterface().ClearExclusiveState();
+
         PreemptSingleCore();
-        auto& scheduler = kernel.Scheduler(current_core);
-        scheduler.RescheduleCurrentCore();
+        HandleInterrupt();
     }
 }
 
 void CpuManager::SingleCoreRunIdleThread() {
     auto& kernel = system.Kernel();
+    kernel.CurrentScheduler()->OnThreadStart();
+
     while (true) {
-        auto& physical_core = kernel.CurrentPhysicalCore();
         PreemptSingleCore(false);
         system.CoreTiming().AddTicks(1000U);
         idle_count++;
-        auto& scheduler = physical_core.Scheduler();
-        scheduler.RescheduleCurrentCore();
+        HandleInterrupt();
     }
 }
 
-void CpuManager::PreemptSingleCore(bool from_running_enviroment) {
-    {
-        auto& kernel = system.Kernel();
-        auto& scheduler = kernel.Scheduler(current_core);
-        Kernel::KThread* current_thread = scheduler.GetSchedulerCurrentThread();
-        if (idle_count >= 4 || from_running_enviroment) {
-            if (!from_running_enviroment) {
-                system.CoreTiming().Idle();
-                idle_count = 0;
-            }
-            kernel.SetIsPhantomModeForSingleCore(true);
-            system.CoreTiming().Advance();
-            kernel.SetIsPhantomModeForSingleCore(false);
-        }
-        current_core.store((current_core + 1) % Core::Hardware::NUM_CPU_CORES);
-        system.CoreTiming().ResetTicks();
-        scheduler.Unload(scheduler.GetSchedulerCurrentThread());
+void CpuManager::PreemptSingleCore(bool from_running_environment) {
+    auto& kernel = system.Kernel();
 
-        auto& next_scheduler = kernel.Scheduler(current_core);
-        Common::Fiber::YieldTo(current_thread->GetHostContext(), *next_scheduler.ControlContext());
-    }
-
-    // May have changed scheduler
-    {
-        auto& scheduler = system.Kernel().Scheduler(current_core);
-        scheduler.Reload(scheduler.GetSchedulerCurrentThread());
-        if (!scheduler.IsIdle()) {
+    if (idle_count >= 4 || from_running_environment) {
+        if (!from_running_environment) {
+            system.CoreTiming().Idle();
             idle_count = 0;
         }
+        kernel.SetIsPhantomModeForSingleCore(true);
+        system.CoreTiming().Advance();
+        kernel.SetIsPhantomModeForSingleCore(false);
     }
+    current_core.store((current_core + 1) % Core::Hardware::NUM_CPU_CORES);
+    system.CoreTiming().ResetTicks();
+    kernel.Scheduler(current_core).PreemptSingleCore();
+
+    // We've now been scheduled again, and we may have exchanged schedulers.
+    // Reload the scheduler in case it's different.
+    if (!kernel.Scheduler(current_core).IsIdle()) {
+        idle_count = 0;
+    }
+}
+
+void CpuManager::GuestActivate() {
+    // Similar to the HorizonKernelMain callback in HOS
+    auto& kernel = system.Kernel();
+    auto* scheduler = kernel.CurrentScheduler();
+
+    scheduler->Activate();
+    UNREACHABLE();
 }
 
 void CpuManager::ShutdownThread() {
     auto& kernel = system.Kernel();
+    auto* thread = kernel.GetCurrentEmuThread();
     auto core = is_multicore ? kernel.CurrentPhysicalCoreIndex() : 0;
-    auto* current_thread = kernel.GetCurrentEmuThread();
 
-    Common::Fiber::YieldTo(current_thread->GetHostContext(), *core_data[core].host_context);
+    Common::Fiber::YieldTo(thread->GetHostContext(), *core_data[core].host_context);
     UNREACHABLE();
 }
 
@@ -218,9 +212,12 @@ void CpuManager::RunThread(std::size_t core) {
         system.GPU().ObtainContext();
     }
 
-    auto* current_thread = system.Kernel().CurrentScheduler()->GetIdleThread();
-    Kernel::SetCurrentThread(system.Kernel(), current_thread);
-    Common::Fiber::YieldTo(data.host_context, *current_thread->GetHostContext());
+    auto& kernel = system.Kernel();
+    auto& scheduler = *kernel.CurrentScheduler();
+    auto* thread = scheduler.GetSchedulerCurrentThread();
+    Kernel::SetCurrentThread(kernel, thread);
+
+    Common::Fiber::YieldTo(data.host_context, *thread->GetHostContext());
 }
 
 } // namespace Core

src/core/cpu_manager.h

@@ -50,7 +50,10 @@ public:
     void Initialize();
     void Shutdown();
 
-    std::function<void()> GetGuestThreadStartFunc() {
+    std::function<void()> GetGuestActivateFunc() {
+        return [this] { GuestActivate(); };
+    }
+    std::function<void()> GetGuestThreadFunc() {
         return [this] { GuestThreadFunction(); };
     }
     std::function<void()> GetIdleThreadStartFunc() {
@@ -68,20 +71,19 @@ public:
 
 private:
     void GuestThreadFunction();
-    void GuestRewindFunction();
     void IdleThreadFunction();
     void ShutdownThreadFunction();
 
     void MultiCoreRunGuestThread();
-    void MultiCoreRunGuestLoop();
     void MultiCoreRunIdleThread();
 
     void SingleCoreRunGuestThread();
-    void SingleCoreRunGuestLoop();
     void SingleCoreRunIdleThread();
 
     static void ThreadStart(std::stop_token stop_token, CpuManager& cpu_manager, std::size_t core);
 
+    void GuestActivate();
+    void HandleInterrupt();
     void ShutdownThread();
     void RunThread(std::size_t core);
 

src/core/hle/kernel/global_scheduler_context.cpp

@@ -41,12 +41,7 @@ void GlobalSchedulerContext::PreemptThreads() {
     ASSERT(IsLocked());
     for (u32 core_id = 0; core_id < Core::Hardware::NUM_CPU_CORES; core_id++) {
         const u32 priority = preemption_priorities[core_id];
-        kernel.Scheduler(core_id).RotateScheduledQueue(core_id, priority);
-
-        // Signal an interrupt occurred. For core 3, this is a certainty, as preemption will result
-        // in the rotator thread being scheduled. For cores 0-2, this is to simulate or system
-        // interrupts that may have occurred.
-        kernel.PhysicalCore(core_id).Interrupt();
+        KScheduler::RotateScheduledQueue(kernel, core_id, priority);
     }
 }
 

src/core/hle/kernel/k_interrupt_manager.cpp

@@ -6,6 +6,7 @@
 #include "core/hle/kernel/k_scheduler.h"
 #include "core/hle/kernel/k_thread.h"
 #include "core/hle/kernel/kernel.h"
+#include "core/hle/kernel/physical_core.h"
 
 namespace Kernel::KInterruptManager {
 
@@ -15,6 +16,9 @@ void HandleInterrupt(KernelCore& kernel, s32 core_id) {
         return;
     }
 
+    // Acknowledge the interrupt.
+    kernel.PhysicalCore(core_id).ClearInterrupt();
+
     auto& current_thread = GetCurrentThread(kernel);
 
     // If the user disable count is set, we may need to pin the current thread.
@@ -27,6 +31,9 @@ void HandleInterrupt(KernelCore& kernel, s32 core_id) {
         // Set the interrupt flag for the thread.
         GetCurrentThread(kernel).SetInterruptFlag();
     }
+
+    // Request interrupt scheduling.
+    kernel.CurrentScheduler()->RequestScheduleOnInterrupt();
 }
 
 } // namespace Kernel::KInterruptManager

src/core/hle/kernel/k_scheduler.h

@@ -11,6 +11,7 @@
 #include "core/hle/kernel/k_scheduler_lock.h"
 #include "core/hle/kernel/k_scoped_lock.h"
 #include "core/hle/kernel/k_spin_lock.h"
+#include "core/hle/kernel/k_thread.h"
 
 namespace Common {
 class Fiber;
@@ -23,184 +24,150 @@ class System;
 namespace Kernel {
 
 class KernelCore;
+class KInterruptTaskManager;
 class KProcess;
-class SchedulerLock;
 class KThread;
+class KScopedDisableDispatch;
+class KScopedSchedulerLock;
+class KScopedSchedulerLockAndSleep;
 
 class KScheduler final {
 public:
-    explicit KScheduler(Core::System& system_, s32 core_id_);
+    YUZU_NON_COPYABLE(KScheduler);
+    YUZU_NON_MOVEABLE(KScheduler);
+
+    using LockType = KAbstractSchedulerLock<KScheduler>;
+
+    explicit KScheduler(KernelCore& kernel);
     ~KScheduler();
 
-    void Finalize();
-
-    /// Reschedules to the next available thread (call after current thread is suspended)
-    void RescheduleCurrentCore();
-
-    /// Reschedules cores pending reschedule, to be called on EnableScheduling.
-    static void RescheduleCores(KernelCore& kernel, u64 cores_pending_reschedule);
-
-    /// The next two are for SingleCore Only.
-    /// Unload current thread before preempting core.
+    void Initialize(KThread* main_thread, KThread* idle_thread, s32 core_id);
+    void Activate();
+    void OnThreadStart();
     void Unload(KThread* thread);
-
-    /// Reload current thread after core preemption.
     void Reload(KThread* thread);
 
-    /// Gets the current running thread
-    [[nodiscard]] KThread* GetSchedulerCurrentThread() const;
+    void SetInterruptTaskRunnable();
+    void RequestScheduleOnInterrupt();
+    void PreemptSingleCore();
 
-    /// Gets the idle thread
-    [[nodiscard]] KThread* GetIdleThread() const {
-        return idle_thread;
+    u64 GetIdleCount() {
+        return m_state.idle_count;
     }
 
-    /// Returns true if the scheduler is idle
-    [[nodiscard]] bool IsIdle() const {
-        return GetSchedulerCurrentThread() == idle_thread;
+    KThread* GetIdleThread() const {
+        return m_idle_thread;
     }
 
-    /// Gets the timestamp for the last context switch in ticks.
-    [[nodiscard]] u64 GetLastContextSwitchTicks() const;
-
-    [[nodiscard]] bool ContextSwitchPending() const {
-        return state.needs_scheduling.load(std::memory_order_relaxed);
+    bool IsIdle() const {
+        return m_current_thread.load() == m_idle_thread;
     }
 
-    void Initialize();
-
-    void OnThreadStart();
-
-    [[nodiscard]] std::shared_ptr<Common::Fiber>& ControlContext() {
-        return switch_fiber;
+    KThread* GetPreviousThread() const {
+        return m_state.prev_thread;
     }
 
-    [[nodiscard]] const std::shared_ptr<Common::Fiber>& ControlContext() const {
-        return switch_fiber;
+    KThread* GetSchedulerCurrentThread() const {
+        return m_current_thread.load();
     }
 
-    [[nodiscard]] u64 UpdateHighestPriorityThread(KThread* highest_thread);
+    s64 GetLastContextSwitchTime() const {
+        return m_last_context_switch_time;
+    }
 
-    /**
-     * Takes a thread and moves it to the back of the it's priority list.
-     *
-     * @note This operation can be redundant and no scheduling is changed if marked as so.
-     */
-    static void YieldWithoutCoreMigration(KernelCore& kernel);
+    // Static public API.
+    static bool CanSchedule(KernelCore& kernel) {
+        return GetCurrentThread(kernel).GetDisableDispatchCount() == 0;
+    }
+    static bool IsSchedulerLockedByCurrentThread(KernelCore& kernel) {
+        return kernel.GlobalSchedulerContext().scheduler_lock.IsLockedByCurrentThread();
+    }
 
-    /**
-     * Takes a thread and moves it to the back of the it's priority list.
-     * Afterwards, tries to pick a suggested thread from the suggested queue that has worse time or
-     * a better priority than the next thread in the core.
-     *
-     * @note This operation can be redundant and no scheduling is changed if marked as so.
-     */
-    static void YieldWithCoreMigration(KernelCore& kernel);
+    static bool IsSchedulerUpdateNeeded(KernelCore& kernel) {
+        return kernel.GlobalSchedulerContext().scheduler_update_needed;
+    }
+    static void SetSchedulerUpdateNeeded(KernelCore& kernel) {
+        kernel.GlobalSchedulerContext().scheduler_update_needed = true;
+    }
+    static void ClearSchedulerUpdateNeeded(KernelCore& kernel) {
+        kernel.GlobalSchedulerContext().scheduler_update_needed = false;
+    }
 
-    /**
-     * Takes a thread and moves it out of the scheduling queue.
-     * and into the suggested queue. If no thread can be scheduled afterwards in that core,
-     * a suggested thread is obtained instead.
-     *
-     * @note This operation can be redundant and no scheduling is changed if marked as so.
-     */
-    static void YieldToAnyThread(KernelCore& kernel);
+    static void DisableScheduling(KernelCore& kernel);
+    static void EnableScheduling(KernelCore& kernel, u64 cores_needing_scheduling);
+
+    static u64 UpdateHighestPriorityThreads(KernelCore& kernel);
 
     static void ClearPreviousThread(KernelCore& kernel, KThread* thread);
 
-    /// Notify the scheduler a thread's status has changed.
     static void OnThreadStateChanged(KernelCore& kernel, KThread* thread, ThreadState old_state);
-
-    /// Notify the scheduler a thread's priority has changed.
     static void OnThreadPriorityChanged(KernelCore& kernel, KThread* thread, s32 old_priority);
-
-    /// Notify the scheduler a thread's core and/or affinity mask has changed.
     static void OnThreadAffinityMaskChanged(KernelCore& kernel, KThread* thread,
                                             const KAffinityMask& old_affinity, s32 old_core);
 
-    static bool CanSchedule(KernelCore& kernel);
-    static bool IsSchedulerUpdateNeeded(const KernelCore& kernel);
-    static void SetSchedulerUpdateNeeded(KernelCore& kernel);
-    static void ClearSchedulerUpdateNeeded(KernelCore& kernel);
-    static void DisableScheduling(KernelCore& kernel);
-    static void EnableScheduling(KernelCore& kernel, u64 cores_needing_scheduling);
-    [[nodiscard]] static u64 UpdateHighestPriorityThreads(KernelCore& kernel);
+    static void RotateScheduledQueue(KernelCore& kernel, s32 core_id, s32 priority);
+    static void RescheduleCores(KernelCore& kernel, u64 cores_needing_scheduling);
+
+    static void YieldWithoutCoreMigration(KernelCore& kernel);
+    static void YieldWithCoreMigration(KernelCore& kernel);
+    static void YieldToAnyThread(KernelCore& kernel);
 
 private:
-    friend class GlobalSchedulerContext;
+    // Static private API.
+    static KSchedulerPriorityQueue& GetPriorityQueue(KernelCore& kernel) {
+        return kernel.GlobalSchedulerContext().priority_queue;
+    }
+    static u64 UpdateHighestPriorityThreadsImpl(KernelCore& kernel);
 
-    /**
-     * Takes care of selecting the new scheduled threads in three steps:
-     *
-     * 1. First a thread is selected from the top of the priority queue. If no thread
-     *    is obtained then we move to step two, else we are done.
-     *
-     * 2. Second we try to get a suggested thread that's not assigned to any core or
-     *    that is not the top thread in that core.
-     *
-     * 3. Third is no suggested thread is found, we do a second pass and pick a running
-     *    thread in another core and swap it with its current thread.
-     *
-     * returns the cores needing scheduling.
-     */
-    [[nodiscard]] static u64 UpdateHighestPriorityThreadsImpl(KernelCore& kernel);
+    static void RescheduleCurrentHLEThread(KernelCore& kernel);
 
-    [[nodiscard]] static KSchedulerPriorityQueue& GetPriorityQueue(KernelCore& kernel);
-
-    void RotateScheduledQueue(s32 cpu_core_id, s32 priority);
+    // Instanced private API.
+    void ScheduleImpl();
+    void ScheduleImplFiber();
+    void SwitchThread(KThread* next_thread);
 
     void Schedule();
+    void ScheduleOnInterrupt();
 
-    /// Switches the CPU's active thread context to that of the specified thread
-    void ScheduleImpl();
+    void RescheduleOtherCores(u64 cores_needing_scheduling);
+    void RescheduleCurrentCore();
+    void RescheduleCurrentCoreImpl();
 
-    /// When a thread wakes up, it must run this through it's new scheduler
-    void SwitchContextStep2();
+    u64 UpdateHighestPriorityThread(KThread* thread);
 
-    /**
-     * Called on every context switch to update the internal timestamp
-     * This also updates the running time ticks for the given thread and
-     * process using the following difference:
-     *
-     * ticks += most_recent_ticks - last_context_switch_ticks
-     *
-     * The internal tick timestamp for the scheduler is simply the
-     * most recent tick count retrieved. No special arithmetic is
-     * applied to it.
-     */
-    void UpdateLastContextSwitchTime(KThread* thread, KProcess* process);
-
-    void SwitchToCurrent();
-
-    KThread* prev_thread{};
-    std::atomic<KThread*> current_thread{};
-
-    KThread* idle_thread{};
-
-    std::shared_ptr<Common::Fiber> switch_fiber{};
+private:
+    friend class KScopedDisableDispatch;
 
     struct SchedulingState {
-        std::atomic<bool> needs_scheduling{};
-        bool interrupt_task_thread_runnable{};
-        bool should_count_idle{};
-        u64 idle_count{};
-        KThread* highest_priority_thread{};
-        void* idle_thread_stack{};
+        std::atomic<bool> needs_scheduling{false};
+        bool interrupt_task_runnable{false};
+        bool should_count_idle{false};
+        u64 idle_count{0};
+        KThread* highest_priority_thread{nullptr};
+        void* idle_thread_stack{nullptr};
+        std::atomic<KThread*> prev_thread{nullptr};
+        KInterruptTaskManager* interrupt_task_manager{nullptr};
     };
 
-    SchedulingState state;
+    KernelCore& kernel;
+    SchedulingState m_state;
+    bool m_is_active{false};
+    s32 m_core_id{0};
+    s64 m_last_context_switch_time{0};
+    KThread* m_idle_thread{nullptr};
+    std::atomic<KThread*> m_current_thread{nullptr};
 
-    Core::System& system;
-    u64 last_context_switch_time{};
-    const s32 core_id;
-
-    KSpinLock guard{};
+    std::shared_ptr<Common::Fiber> m_switch_fiber{};
+    KThread* m_switch_cur_thread{};
+    KThread* m_switch_highest_priority_thread{};
+    bool m_switch_from_schedule{};
 };
 
-class [[nodiscard]] KScopedSchedulerLock : KScopedLock<GlobalSchedulerContext::LockType> {
+class KScopedSchedulerLock : public KScopedLock<KScheduler::LockType> {
 public:
-    explicit KScopedSchedulerLock(KernelCore& kernel);
-    ~KScopedSchedulerLock();
+    explicit KScopedSchedulerLock(KernelCore& kernel)
+        : KScopedLock(kernel.GlobalSchedulerContext().scheduler_lock) {}
+    ~KScopedSchedulerLock() = default;
 };
 
 } // namespace Kernel

src/core/hle/kernel/k_scheduler_lock.h

@@ -5,9 +5,11 @@
 
 #include <atomic>
 #include "common/assert.h"
+#include "core/hle/kernel/k_interrupt_manager.h"
 #include "core/hle/kernel/k_spin_lock.h"
 #include "core/hle/kernel/k_thread.h"
 #include "core/hle/kernel/kernel.h"
+#include "core/hle/kernel/physical_core.h"
 
 namespace Kernel {
 

src/core/hle/kernel/k_thread.cpp

@@ -258,7 +258,18 @@ Result KThread::InitializeThread(KThread* thread, KThreadFunction func, uintptr_
 }
 
 Result KThread::InitializeDummyThread(KThread* thread) {
-    return thread->Initialize({}, {}, {}, DummyThreadPriority, 3, {}, ThreadType::Dummy);
+    // Initialize the thread.
+    R_TRY(thread->Initialize({}, {}, {}, DummyThreadPriority, 3, {}, ThreadType::Dummy));
+
+    // Initialize emulation parameters.
+    thread->stack_parameters.disable_count = 0;
+
+    return ResultSuccess;
+}
+
+Result KThread::InitializeMainThread(Core::System& system, KThread* thread, s32 virt_core) {
+    return InitializeThread(thread, {}, {}, {}, IdleThreadPriority, virt_core, {}, ThreadType::Main,
+                            system.GetCpuManager().GetGuestActivateFunc());
 }
 
 Result KThread::InitializeIdleThread(Core::System& system, KThread* thread, s32 virt_core) {
@@ -277,7 +288,7 @@ Result KThread::InitializeUserThread(Core::System& system, KThread* thread, KThr
                                      KProcess* owner) {
     system.Kernel().GlobalSchedulerContext().AddThread(thread);
     return InitializeThread(thread, func, arg, user_stack_top, prio, virt_core, owner,
-                            ThreadType::User, system.GetCpuManager().GetGuestThreadStartFunc());
+                            ThreadType::User, system.GetCpuManager().GetGuestThreadFunc());
 }
 
 void KThread::PostDestroy(uintptr_t arg) {
@@ -1058,6 +1069,8 @@ void KThread::Exit() {
         // Register the thread as a work task.
         KWorkerTaskManager::AddTask(kernel, KWorkerTaskManager::WorkerType::Exit, this);
     }
+
+    UNREACHABLE_MSG("KThread::Exit() would return");
 }
 
 Result KThread::Sleep(s64 timeout) {
@@ -1093,6 +1106,8 @@ void KThread::IfDummyThreadTryWait() {
         return;
     }
 
+    ASSERT(!kernel.IsPhantomModeForSingleCore());
+
     // Block until we are no longer waiting.
     std::unique_lock lk(dummy_wait_lock);
     dummy_wait_cv.wait(
@@ -1197,16 +1212,13 @@ KScopedDisableDispatch::~KScopedDisableDispatch() {
         return;
     }
 
-    // Skip the reschedule if single-core, as dispatch tracking is disabled here.
-    if (!Settings::values.use_multi_core.GetValue()) {
-        return;
-    }
-
     if (GetCurrentThread(kernel).GetDisableDispatchCount() <= 1) {
-        auto scheduler = kernel.CurrentScheduler();
+        auto* scheduler = kernel.CurrentScheduler();
 
-        if (scheduler) {
+        if (scheduler && !kernel.IsPhantomModeForSingleCore()) {
             scheduler->RescheduleCurrentCore();
+        } else {
+            KScheduler::RescheduleCurrentHLEThread(kernel);
         }
     } else {
         GetCurrentThread(kernel).EnableDispatch();

src/core/hle/kernel/k_thread.h

@@ -413,6 +413,9 @@ public:
 
     [[nodiscard]] static Result InitializeDummyThread(KThread* thread);
 
+    [[nodiscard]] static Result InitializeMainThread(Core::System& system, KThread* thread,
+                                                     s32 virt_core);
+
     [[nodiscard]] static Result InitializeIdleThread(Core::System& system, KThread* thread,
                                                      s32 virt_core);
 
@@ -480,39 +483,16 @@ public:
         return per_core_priority_queue_entry[core];
     }
 
-    [[nodiscard]] bool IsKernelThread() const {
-        return GetActiveCore() == 3;
-    }
-
-    [[nodiscard]] bool IsDispatchTrackingDisabled() const {
-        return is_single_core || IsKernelThread();
-    }
-
     [[nodiscard]] s32 GetDisableDispatchCount() const {
-        if (IsDispatchTrackingDisabled()) {
-            // TODO(bunnei): Until kernel threads are emulated, we cannot enable/disable dispatch.
-            return 1;
-        }
-
         return this->GetStackParameters().disable_count;
     }
 
     void DisableDispatch() {
-        if (IsDispatchTrackingDisabled()) {
-            // TODO(bunnei): Until kernel threads are emulated, we cannot enable/disable dispatch.
-            return;
-        }
-
         ASSERT(GetCurrentThread(kernel).GetDisableDispatchCount() >= 0);
         this->GetStackParameters().disable_count++;
     }
 
     void EnableDispatch() {
-        if (IsDispatchTrackingDisabled()) {
-            // TODO(bunnei): Until kernel threads are emulated, we cannot enable/disable dispatch.
-            return;
-        }
-
         ASSERT(GetCurrentThread(kernel).GetDisableDispatchCount() > 0);
         this->GetStackParameters().disable_count--;
     }

src/core/hle/kernel/kernel.cpp

@@ -64,8 +64,6 @@ struct KernelCore::Impl {
 
         is_phantom_mode_for_singlecore = false;
 
-        InitializePhysicalCores();
-
         // Derive the initial memory layout from the emulated board
         Init::InitializeSlabResourceCounts(kernel);
         DeriveInitialMemoryLayout();
@@ -75,9 +73,9 @@ struct KernelCore::Impl {
         InitializeSystemResourceLimit(kernel, system.CoreTiming());
         InitializeMemoryLayout();
         Init::InitializeKPageBufferSlabHeap(system);
-        InitializeSchedulers();
         InitializeShutdownThreads();
         InitializePreemption(kernel);
+        InitializePhysicalCores();
 
         RegisterHostThread();
     }
@@ -136,7 +134,6 @@ struct KernelCore::Impl {
                 shutdown_threads[core_id] = nullptr;
             }
 
-            schedulers[core_id]->Finalize();
             schedulers[core_id].reset();
         }
 
@@ -199,14 +196,21 @@ struct KernelCore::Impl {
         exclusive_monitor =
             Core::MakeExclusiveMonitor(system.Memory(), Core::Hardware::NUM_CPU_CORES);
         for (u32 i = 0; i < Core::Hardware::NUM_CPU_CORES; i++) {
-            schedulers[i] = std::make_unique<Kernel::KScheduler>(system, i);
-            cores.emplace_back(i, system, *schedulers[i], interrupts);
-        }
-    }
+            const s32 core{static_cast<s32>(i)};
 
-    void InitializeSchedulers() {
-        for (u32 i = 0; i < Core::Hardware::NUM_CPU_CORES; i++) {
-            cores[i].Scheduler().Initialize();
+            schedulers[i] = std::make_unique<Kernel::KScheduler>(system.Kernel());
+            cores.emplace_back(i, system, *schedulers[i], interrupts);
+
+            auto* main_thread{Kernel::KThread::Create(system.Kernel())};
+            main_thread->SetName(fmt::format("MainThread:{}", core));
+            main_thread->SetCurrentCore(core);
+            ASSERT(Kernel::KThread::InitializeMainThread(system, main_thread, core).IsSuccess());
+
+            auto* idle_thread{Kernel::KThread::Create(system.Kernel())};
+            idle_thread->SetCurrentCore(core);
+            ASSERT(Kernel::KThread::InitializeIdleThread(system, idle_thread, core).IsSuccess());
+
+            schedulers[i]->Initialize(main_thread, idle_thread, core);
         }
     }
 
@@ -1109,10 +1113,11 @@ void KernelCore::Suspend(bool suspended) {
 }
 
 void KernelCore::ShutdownCores() {
+    KScopedSchedulerLock lk{*this};
+
     for (auto* thread : impl->shutdown_threads) {
         void(thread->Run());
     }
-    InterruptAllPhysicalCores();
 }
 
 bool KernelCore::IsMulticore() const {

src/core/hle/kernel/physical_core.cpp

@@ -43,6 +43,7 @@ void PhysicalCore::Initialize([[maybe_unused]] bool is_64_bit) {
 
 void PhysicalCore::Run() {
     arm_interface->Run();
+    arm_interface->ClearExclusiveState();
 }
 
 void PhysicalCore::Idle() {

src/core/hle/kernel/svc.cpp

@@ -887,7 +887,7 @@ static Result GetInfo(Core::System& system, u64* result, u64 info_id, Handle han
         const auto* const current_thread = GetCurrentThreadPointer(system.Kernel());
         const bool same_thread = current_thread == thread.GetPointerUnsafe();
 
-        const u64 prev_ctx_ticks = scheduler.GetLastContextSwitchTicks();
+        const u64 prev_ctx_ticks = scheduler.GetLastContextSwitchTime();
         u64 out_ticks = 0;
         if (same_thread && info_sub_id == 0xFFFFFFFFFFFFFFFF) {
             const u64 thread_ticks = current_thread->GetCpuTime();
@@ -3026,11 +3026,6 @@ void Call(Core::System& system, u32 immediate) {
     }
 
     kernel.ExitSVCProfile();
-
-    if (!thread->IsCallingSvc()) {
-        auto* host_context = thread->GetHostContext().get();
-        host_context->Rewind();
-    }
 }
 
 } // namespace Kernel::Svc