23 files changed, 479 insertions, 361 deletions

diff --git a/src/core/hle/service/acc/profile_manager.cpp b/src/core/hle/service/acc/profile_manager.cpp
index 5542d6cbc..683f44e27 100644
--- a/src/core/hle/service/acc/profile_manager.cpp
+++ b/src/core/hle/service/acc/profile_manager.cpp
@@ -61,9 +61,7 @@ ProfileManager::ProfileManager() {
     OpenUser(*GetUser(current));
 }
 
-ProfileManager::~ProfileManager() {
-    WriteUserSaveFile();
-}
+ProfileManager::~ProfileManager() = default;
 
 /// After a users creation it needs to be "registered" to the system. AddToProfiles handles the
 /// internal management of the users profiles
@@ -113,6 +111,8 @@ Result ProfileManager::CreateNewUser(UUID uuid, const ProfileUsername& username)
         return ERROR_USER_ALREADY_EXISTS;
     }
 
+    is_save_needed = true;
+
     return AddUser({
         .user_uuid = uuid,
         .username = username,
@@ -326,6 +326,9 @@ bool ProfileManager::RemoveUser(UUID uuid) {
     profiles[*index] = ProfileInfo{};
     std::stable_partition(profiles.begin(), profiles.end(),
                           [](const ProfileInfo& profile) { return profile.user_uuid.IsValid(); });
+
+    is_save_needed = true;
+
     return true;
 }
 
@@ -340,6 +343,8 @@ bool ProfileManager::SetProfileBase(UUID uuid, const ProfileBase& profile_new) {
     profile.username = profile_new.username;
     profile.creation_time = profile_new.timestamp;
 
+    is_save_needed = true;
+
     return true;
 }
 
@@ -348,6 +353,7 @@ bool ProfileManager::SetProfileBaseAndData(Common::UUID uuid, const ProfileBase&
     const auto index = GetUserIndex(uuid);
     if (index.has_value() && SetProfileBase(uuid, profile_new)) {
         profiles[*index].data = data_new;
+        is_save_needed = true;
         return true;
     }
 
@@ -391,6 +397,10 @@ void ProfileManager::ParseUserSaveFile() {
 }
 
 void ProfileManager::WriteUserSaveFile() {
+    if (!is_save_needed) {
+        return;
+    }
+
     ProfileDataRaw raw{};
 
     for (std::size_t i = 0; i < MAX_USERS; ++i) {
@@ -423,7 +433,10 @@ void ProfileManager::WriteUserSaveFile() {
     if (!save.IsOpen() || !save.SetSize(sizeof(ProfileDataRaw)) || !save.WriteObject(raw)) {
         LOG_WARNING(Service_ACC, "Failed to write save data to file... No changes to user data "
                                  "made in current session will be saved.");
+        return;
     }
+
+    is_save_needed = false;
 }
 
 }; // namespace Service::Account
diff --git a/src/core/hle/service/acc/profile_manager.h b/src/core/hle/service/acc/profile_manager.h
index 900e32200..e21863e64 100644
--- a/src/core/hle/service/acc/profile_manager.h
+++ b/src/core/hle/service/acc/profile_manager.h
@@ -103,6 +103,7 @@ private:
     std::optional<std::size_t> AddToProfiles(const ProfileInfo& profile);
     bool RemoveProfileAtIndex(std::size_t index);
 
+    bool is_save_needed{};
     std::array<ProfileInfo, MAX_USERS> profiles{};
     std::array<ProfileInfo, MAX_USERS> stored_opened_profiles{};
     std::size_t user_count{};
diff --git a/src/core/hle/service/am/am.cpp b/src/core/hle/service/am/am.cpp
index 9e05bdafa..a768bdc54 100644
--- a/src/core/hle/service/am/am.cpp
+++ b/src/core/hle/service/am/am.cpp
@@ -36,6 +36,7 @@
 #include "core/hle/service/caps/caps_su.h"
 #include "core/hle/service/caps/caps_types.h"
 #include "core/hle/service/filesystem/filesystem.h"
+#include "core/hle/service/filesystem/save_data_controller.h"
 #include "core/hle/service/ipc_helpers.h"
 #include "core/hle/service/ns/ns.h"
 #include "core/hle/service/nvnflinger/fb_share_buffer_manager.h"
@@ -2178,7 +2179,7 @@ void IApplicationFunctions::EnsureSaveData(HLERequestContext& ctx) {
     attribute.type = FileSys::SaveDataType::SaveData;
 
     FileSys::VirtualDir save_data{};
-    const auto res = system.GetFileSystemController().CreateSaveData(
+    const auto res = system.GetFileSystemController().OpenSaveDataController()->CreateSaveData(
         &save_data, FileSys::SaveDataSpaceId::NandUser, attribute);
 
     IPC::ResponseBuilder rb{ctx, 4};
@@ -2353,7 +2354,7 @@ void IApplicationFunctions::ExtendSaveData(HLERequestContext& ctx) {
               "new_journal={:016X}",
               static_cast<u8>(type), user_id[1], user_id[0], new_normal_size, new_journal_size);
 
-    system.GetFileSystemController().WriteSaveDataSize(
+    system.GetFileSystemController().OpenSaveDataController()->WriteSaveDataSize(
         type, system.GetApplicationProcessProgramID(), user_id,
         {new_normal_size, new_journal_size});
 
@@ -2378,7 +2379,7 @@ void IApplicationFunctions::GetSaveDataSize(HLERequestContext& ctx) {
     LOG_DEBUG(Service_AM, "called with type={:02X}, user_id={:016X}{:016X}", type, user_id[1],
               user_id[0]);
 
-    const auto size = system.GetFileSystemController().ReadSaveDataSize(
+    const auto size = system.GetFileSystemController().OpenSaveDataController()->ReadSaveDataSize(
         type, system.GetApplicationProcessProgramID(), user_id);
 
     IPC::ResponseBuilder rb{ctx, 6};
diff --git a/src/core/hle/service/audio/audin_u.cpp b/src/core/hle/service/audio/audin_u.cpp
index 56fee4591..de2aa6906 100644
--- a/src/core/hle/service/audio/audin_u.cpp
+++ b/src/core/hle/service/audio/audin_u.cpp
@@ -18,11 +18,11 @@ using namespace AudioCore::AudioIn;
 class IAudioIn final : public ServiceFramework<IAudioIn> {
 public:
     explicit IAudioIn(Core::System& system_, Manager& manager, size_t session_id,
-                      const std::string& device_name, const AudioInParameter& in_params, u32 handle,
-                      u64 applet_resource_user_id)
+                      const std::string& device_name, const AudioInParameter& in_params,
+                      Kernel::KProcess* handle, u64 applet_resource_user_id)
         : ServiceFramework{system_, "IAudioIn"},
           service_context{system_, "IAudioIn"}, event{service_context.CreateEvent("AudioInEvent")},
-          impl{std::make_shared<In>(system_, manager, event, session_id)} {
+          process{handle}, impl{std::make_shared<In>(system_, manager, event, session_id)} {
         // clang-format off
         static const FunctionInfo functions[] = {
             {0, &IAudioIn::GetAudioInState, "GetAudioInState"},
@@ -45,6 +45,8 @@ public:
 
         RegisterHandlers(functions);
 
+        process->Open();
+
         if (impl->GetSystem()
                 .Initialize(device_name, in_params, handle, applet_resource_user_id)
                 .IsError()) {
@@ -55,6 +57,7 @@ public:
     ~IAudioIn() override {
         impl->Free();
         service_context.CloseEvent(event);
+        process->Close();
     }
 
     [[nodiscard]] std::shared_ptr<In> GetImpl() {
@@ -196,6 +199,7 @@ private:
 
     KernelHelpers::ServiceContext service_context;
     Kernel::KEvent* event;
+    Kernel::KProcess* process;
     std::shared_ptr<AudioCore::AudioIn::In> impl;
     Common::ScratchBuffer<u64> released_buffer;
 };
@@ -267,6 +271,14 @@ void AudInU::OpenAudioIn(HLERequestContext& ctx) {
     auto device_name = Common::StringFromBuffer(device_name_data);
     auto handle{ctx.GetCopyHandle(0)};
 
+    auto process{ctx.GetObjectFromHandle<Kernel::KProcess>(handle)};
+    if (process.IsNull()) {
+        LOG_ERROR(Service_Audio, "Failed to get process handle");
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(ResultUnknown);
+        return;
+    }
+
     std::scoped_lock l{impl->mutex};
     auto link{impl->LinkToManager()};
     if (link.IsError()) {
@@ -287,8 +299,9 @@ void AudInU::OpenAudioIn(HLERequestContext& ctx) {
     LOG_DEBUG(Service_Audio, "Opening new AudioIn, sessionid={}, free sessions={}", new_session_id,
               impl->num_free_sessions);
 
-    auto audio_in = std::make_shared<IAudioIn>(system, *impl, new_session_id, device_name,
-                                               in_params, handle, applet_resource_user_id);
+    auto audio_in =
+        std::make_shared<IAudioIn>(system, *impl, new_session_id, device_name, in_params,
+                                   process.GetPointerUnsafe(), applet_resource_user_id);
     impl->sessions[new_session_id] = audio_in->GetImpl();
     impl->applet_resource_user_ids[new_session_id] = applet_resource_user_id;
 
@@ -318,6 +331,14 @@ void AudInU::OpenAudioInProtocolSpecified(HLERequestContext& ctx) {
     auto device_name = Common::StringFromBuffer(device_name_data);
     auto handle{ctx.GetCopyHandle(0)};
 
+    auto process{ctx.GetObjectFromHandle<Kernel::KProcess>(handle)};
+    if (process.IsNull()) {
+        LOG_ERROR(Service_Audio, "Failed to get process handle");
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(ResultUnknown);
+        return;
+    }
+
     std::scoped_lock l{impl->mutex};
     auto link{impl->LinkToManager()};
     if (link.IsError()) {
@@ -338,8 +359,9 @@ void AudInU::OpenAudioInProtocolSpecified(HLERequestContext& ctx) {
     LOG_DEBUG(Service_Audio, "Opening new AudioIn, sessionid={}, free sessions={}", new_session_id,
               impl->num_free_sessions);
 
-    auto audio_in = std::make_shared<IAudioIn>(system, *impl, new_session_id, device_name,
-                                               in_params, handle, applet_resource_user_id);
+    auto audio_in =
+        std::make_shared<IAudioIn>(system, *impl, new_session_id, device_name, in_params,
+                                   process.GetPointerUnsafe(), applet_resource_user_id);
     impl->sessions[new_session_id] = audio_in->GetImpl();
     impl->applet_resource_user_ids[new_session_id] = applet_resource_user_id;
 
diff --git a/src/core/hle/service/audio/audout_u.cpp b/src/core/hle/service/audio/audout_u.cpp
index ca683d72c..8cc7b69f4 100644
--- a/src/core/hle/service/audio/audout_u.cpp
+++ b/src/core/hle/service/audio/audout_u.cpp
@@ -26,9 +26,10 @@ class IAudioOut final : public ServiceFramework<IAudioOut> {
 public:
     explicit IAudioOut(Core::System& system_, AudioCore::AudioOut::Manager& manager,
                        size_t session_id, const std::string& device_name,
-                       const AudioOutParameter& in_params, u32 handle, u64 applet_resource_user_id)
+                       const AudioOutParameter& in_params, Kernel::KProcess* handle,
+                       u64 applet_resource_user_id)
         : ServiceFramework{system_, "IAudioOut"}, service_context{system_, "IAudioOut"},
-          event{service_context.CreateEvent("AudioOutEvent")},
+          event{service_context.CreateEvent("AudioOutEvent")}, process{handle},
           impl{std::make_shared<AudioCore::AudioOut::Out>(system_, manager, event, session_id)} {
 
         // clang-format off
@@ -50,11 +51,14 @@ public:
         };
         // clang-format on
         RegisterHandlers(functions);
+
+        process->Open();
     }
 
     ~IAudioOut() override {
         impl->Free();
         service_context.CloseEvent(event);
+        process->Close();
     }
 
     [[nodiscard]] std::shared_ptr<AudioCore::AudioOut::Out> GetImpl() {
@@ -206,6 +210,7 @@ private:
 
     KernelHelpers::ServiceContext service_context;
     Kernel::KEvent* event;
+    Kernel::KProcess* process;
     std::shared_ptr<AudioCore::AudioOut::Out> impl;
     Common::ScratchBuffer<u64> released_buffer;
 };
@@ -257,6 +262,14 @@ void AudOutU::OpenAudioOut(HLERequestContext& ctx) {
     auto device_name = Common::StringFromBuffer(device_name_data);
     auto handle{ctx.GetCopyHandle(0)};
 
+    auto process{ctx.GetObjectFromHandle<Kernel::KProcess>(handle)};
+    if (process.IsNull()) {
+        LOG_ERROR(Service_Audio, "Failed to get process handle");
+        IPC::ResponseBuilder rb{ctx, 2};
+        rb.Push(ResultUnknown);
+        return;
+    }
+
     auto link{impl->LinkToManager()};
     if (link.IsError()) {
         LOG_ERROR(Service_Audio, "Failed to link Audio Out to Audio Manager");
@@ -276,10 +289,11 @@ void AudOutU::OpenAudioOut(HLERequestContext& ctx) {
     LOG_DEBUG(Service_Audio, "Opening new AudioOut, sessionid={}, free sessions={}", new_session_id,
               impl->num_free_sessions);
 
-    auto audio_out = std::make_shared<IAudioOut>(system, *impl, new_session_id, device_name,
-                                                 in_params, handle, applet_resource_user_id);
-    result = audio_out->GetImpl()->GetSystem().Initialize(device_name, in_params, handle,
-                                                          applet_resource_user_id);
+    auto audio_out =
+        std::make_shared<IAudioOut>(system, *impl, new_session_id, device_name, in_params,
+                                    process.GetPointerUnsafe(), applet_resource_user_id);
+    result = audio_out->GetImpl()->GetSystem().Initialize(
+        device_name, in_params, process.GetPointerUnsafe(), applet_resource_user_id);
     if (result.IsError()) {
         LOG_ERROR(Service_Audio, "Failed to initialize the AudioOut System!");
         IPC::ResponseBuilder rb{ctx, 2};
diff --git a/src/core/hle/service/filesystem/filesystem.cpp b/src/core/hle/service/filesystem/filesystem.cpp
index 780f8c74d..ca6d8d607 100644
--- a/src/core/hle/service/filesystem/filesystem.cpp
+++ b/src/core/hle/service/filesystem/filesystem.cpp
@@ -24,15 +24,13 @@
 #include "core/hle/service/filesystem/fsp_ldr.h"
 #include "core/hle/service/filesystem/fsp_pr.h"
 #include "core/hle/service/filesystem/fsp_srv.h"
+#include "core/hle/service/filesystem/romfs_controller.h"
+#include "core/hle/service/filesystem/save_data_controller.h"
 #include "core/hle/service/server_manager.h"
 #include "core/loader/loader.h"
 
 namespace Service::FileSystem {
 
-// A default size for normal/journal save data size if application control metadata cannot be found.
-// This should be large enough to satisfy even the most extreme requirements (~4.2GB)
-constexpr u64 SUFFICIENT_SAVE_DATA_SIZE = 0xF0000000;
-
 static FileSys::VirtualDir GetDirectoryRelativeWrapped(FileSys::VirtualDir base,
                                                        std::string_view dir_name_) {
     std::string dir_name(Common::FS::SanitizePath(dir_name_));
@@ -297,145 +295,65 @@ FileSystemController::FileSystemController(Core::System& system_) : system{syste
 
 FileSystemController::~FileSystemController() = default;
 
-Result FileSystemController::RegisterRomFS(std::unique_ptr<FileSys::RomFSFactory>&& factory) {
-    romfs_factory = std::move(factory);
-    LOG_DEBUG(Service_FS, "Registered RomFS");
-    return ResultSuccess;
-}
-
-Result FileSystemController::RegisterSaveData(std::unique_ptr<FileSys::SaveDataFactory>&& factory) {
-    ASSERT_MSG(save_data_factory == nullptr, "Tried to register a second save data");
-    save_data_factory = std::move(factory);
-    LOG_DEBUG(Service_FS, "Registered save data");
-    return ResultSuccess;
-}
+Result FileSystemController::RegisterProcess(
+    ProcessId process_id, ProgramId program_id,
+    std::shared_ptr<FileSys::RomFSFactory>&& romfs_factory) {
+    std::scoped_lock lk{registration_lock};
 
-Result FileSystemController::RegisterSDMC(std::unique_ptr<FileSys::SDMCFactory>&& factory) {
-    ASSERT_MSG(sdmc_factory == nullptr, "Tried to register a second SDMC");
-    sdmc_factory = std::move(factory);
-    LOG_DEBUG(Service_FS, "Registered SDMC");
-    return ResultSuccess;
-}
+    registrations.emplace(process_id, Registration{
+                                          .program_id = program_id,
+                                          .romfs_factory = std::move(romfs_factory),
+                                          .save_data_factory = CreateSaveDataFactory(program_id),
+                                      });
 
-Result FileSystemController::RegisterBIS(std::unique_ptr<FileSys::BISFactory>&& factory) {
-    ASSERT_MSG(bis_factory == nullptr, "Tried to register a second BIS");
-    bis_factory = std::move(factory);
-    LOG_DEBUG(Service_FS, "Registered BIS");
+    LOG_DEBUG(Service_FS, "Registered for process {}", process_id);
     return ResultSuccess;
 }
 
-void FileSystemController::SetPackedUpdate(FileSys::VirtualFile update_raw) {
-    LOG_TRACE(Service_FS, "Setting packed update for romfs");
-
-    if (romfs_factory == nullptr)
-        return;
-
-    romfs_factory->SetPackedUpdate(std::move(update_raw));
-}
-
-FileSys::VirtualFile FileSystemController::OpenRomFSCurrentProcess() const {
-    LOG_TRACE(Service_FS, "Opening RomFS for current process");
-
-    if (romfs_factory == nullptr) {
-        return nullptr;
-    }
-
-    return romfs_factory->OpenCurrentProcess(system.GetApplicationProcessProgramID());
-}
-
-FileSys::VirtualFile FileSystemController::OpenPatchedRomFS(u64 title_id,
-                                                            FileSys::ContentRecordType type) const {
-    LOG_TRACE(Service_FS, "Opening patched RomFS for title_id={:016X}", title_id);
-
-    if (romfs_factory == nullptr) {
-        return nullptr;
-    }
-
-    return romfs_factory->OpenPatchedRomFS(title_id, type);
-}
-
-FileSys::VirtualFile FileSystemController::OpenPatchedRomFSWithProgramIndex(
-    u64 title_id, u8 program_index, FileSys::ContentRecordType type) const {
-    LOG_TRACE(Service_FS, "Opening patched RomFS for title_id={:016X}, program_index={}", title_id,
-              program_index);
-
-    if (romfs_factory == nullptr) {
-        return nullptr;
-    }
-
-    return romfs_factory->OpenPatchedRomFSWithProgramIndex(title_id, program_index, type);
-}
-
-FileSys::VirtualFile FileSystemController::OpenRomFS(u64 title_id, FileSys::StorageId storage_id,
-                                                     FileSys::ContentRecordType type) const {
-    LOG_TRACE(Service_FS, "Opening RomFS for title_id={:016X}, storage_id={:02X}, type={:02X}",
-              title_id, storage_id, type);
-
-    if (romfs_factory == nullptr) {
-        return nullptr;
-    }
-
-    return romfs_factory->Open(title_id, storage_id, type);
-}
-
-std::shared_ptr<FileSys::NCA> FileSystemController::OpenBaseNca(
-    u64 title_id, FileSys::StorageId storage_id, FileSys::ContentRecordType type) const {
-    return romfs_factory->GetEntry(title_id, storage_id, type);
-}
-
-Result FileSystemController::CreateSaveData(FileSys::VirtualDir* out_save_data,
-                                            FileSys::SaveDataSpaceId space,
-                                            const FileSys::SaveDataAttribute& save_struct) const {
-    LOG_TRACE(Service_FS, "Creating Save Data for space_id={:01X}, save_struct={}", space,
-              save_struct.DebugInfo());
+Result FileSystemController::OpenProcess(
+    ProgramId* out_program_id, std::shared_ptr<SaveDataController>* out_save_data_controller,
+    std::shared_ptr<RomFsController>* out_romfs_controller, ProcessId process_id) {
+    std::scoped_lock lk{registration_lock};
 
-    if (save_data_factory == nullptr) {
+    const auto it = registrations.find(process_id);
+    if (it == registrations.end()) {
         return FileSys::ERROR_ENTITY_NOT_FOUND;
     }
 
-    auto save_data = save_data_factory->Create(space, save_struct);
-    if (save_data == nullptr) {
-        return FileSys::ERROR_ENTITY_NOT_FOUND;
-    }
-
-    *out_save_data = save_data;
+    *out_program_id = it->second.program_id;
+    *out_save_data_controller =
+        std::make_shared<SaveDataController>(system, it->second.save_data_factory);
+    *out_romfs_controller =
+        std::make_shared<RomFsController>(it->second.romfs_factory, it->second.program_id);
     return ResultSuccess;
 }
 
-Result FileSystemController::OpenSaveData(FileSys::VirtualDir* out_save_data,
-                                          FileSys::SaveDataSpaceId space,
-                                          const FileSys::SaveDataAttribute& attribute) const {
-    LOG_TRACE(Service_FS, "Opening Save Data for space_id={:01X}, save_struct={}", space,
-              attribute.DebugInfo());
-
-    if (save_data_factory == nullptr) {
-        return FileSys::ERROR_ENTITY_NOT_FOUND;
-    }
+void FileSystemController::SetPackedUpdate(ProcessId process_id, FileSys::VirtualFile update_raw) {
+    LOG_TRACE(Service_FS, "Setting packed update for romfs");
 
-    auto save_data = save_data_factory->Open(space, attribute);
-    if (save_data == nullptr) {
-        return FileSys::ERROR_ENTITY_NOT_FOUND;
+    std::scoped_lock lk{registration_lock};
+    const auto it = registrations.find(process_id);
+    if (it == registrations.end()) {
+        return;
     }
 
-    *out_save_data = save_data;
-    return ResultSuccess;
+    it->second.romfs_factory->SetPackedUpdate(std::move(update_raw));
 }
 
-Result FileSystemController::OpenSaveDataSpace(FileSys::VirtualDir* out_save_data_space,
-                                               FileSys::SaveDataSpaceId space) const {
-    LOG_TRACE(Service_FS, "Opening Save Data Space for space_id={:01X}", space);
-
-    if (save_data_factory == nullptr) {
-        return FileSys::ERROR_ENTITY_NOT_FOUND;
-    }
+std::shared_ptr<SaveDataController> FileSystemController::OpenSaveDataController() {
+    return std::make_shared<SaveDataController>(system, CreateSaveDataFactory(ProgramId{}));
+}
 
-    auto save_data_space = save_data_factory->GetSaveDataSpaceDirectory(space);
-    if (save_data_space == nullptr) {
-        return FileSys::ERROR_ENTITY_NOT_FOUND;
-    }
+std::shared_ptr<FileSys::SaveDataFactory> FileSystemController::CreateSaveDataFactory(
+    ProgramId program_id) {
+    using YuzuPath = Common::FS::YuzuPath;
+    const auto rw_mode = FileSys::Mode::ReadWrite;
 
-    *out_save_data_space = save_data_space;
-    return ResultSuccess;
+    auto vfs = system.GetFilesystem();
+    const auto nand_directory =
+        vfs->OpenDirectory(Common::FS::GetYuzuPathString(YuzuPath::NANDDir), rw_mode);
+    return std::make_shared<FileSys::SaveDataFactory>(system, program_id,
+                                                      std::move(nand_directory));
 }
 
 Result FileSystemController::OpenSDMC(FileSys::VirtualDir* out_sdmc) const {
@@ -540,48 +458,6 @@ u64 FileSystemController::GetTotalSpaceSize(FileSys::StorageId id) const {
     return 0;
 }
 
-FileSys::SaveDataSize FileSystemController::ReadSaveDataSize(FileSys::SaveDataType type,
-                                                             u64 title_id, u128 user_id) const {
-    if (save_data_factory == nullptr) {
-        return {0, 0};
-    }
-
-    const auto value = save_data_factory->ReadSaveDataSize(type, title_id, user_id);
-
-    if (value.normal == 0 && value.journal == 0) {
-        FileSys::SaveDataSize new_size{SUFFICIENT_SAVE_DATA_SIZE, SUFFICIENT_SAVE_DATA_SIZE};
-
-        FileSys::NACP nacp;
-        const auto res = system.GetAppLoader().ReadControlData(nacp);
-
-        if (res != Loader::ResultStatus::Success) {
-            const FileSys::PatchManager pm{system.GetApplicationProcessProgramID(),
-                                           system.GetFileSystemController(),
-                                           system.GetContentProvider()};
-            const auto metadata = pm.GetControlMetadata();
-            const auto& nacp_unique = metadata.first;
-
-            if (nacp_unique != nullptr) {
-                new_size = {nacp_unique->GetDefaultNormalSaveSize(),
-                            nacp_unique->GetDefaultJournalSaveSize()};
-            }
-        } else {
-            new_size = {nacp.GetDefaultNormalSaveSize(), nacp.GetDefaultJournalSaveSize()};
-        }
-
-        WriteSaveDataSize(type, title_id, user_id, new_size);
-        return new_size;
-    }
-
-    return value;
-}
-
-void FileSystemController::WriteSaveDataSize(FileSys::SaveDataType type, u64 title_id, u128 user_id,
-                                             FileSys::SaveDataSize new_value) const {
-    if (save_data_factory != nullptr)
-        save_data_factory->WriteSaveDataSize(type, title_id, user_id, new_value);
-}
-
 void FileSystemController::SetGameCard(FileSys::VirtualFile file) {
     gamecard = std::make_unique<FileSys::XCI>(file);
     const auto dir = gamecard->ConcatenatedPseudoDirectory();
@@ -801,14 +677,9 @@ FileSys::VirtualDir FileSystemController::GetBCATDirectory(u64 title_id) const {
     return bis_factory->GetBCATDirectory(title_id);
 }
 
-void FileSystemController::SetAutoSaveDataCreation(bool enable) {
-    save_data_factory->SetAutoCreate(enable);
-}
-
 void FileSystemController::CreateFactories(FileSys::VfsFilesystem& vfs, bool overwrite) {
     if (overwrite) {
         bis_factory = nullptr;
-        save_data_factory = nullptr;
         sdmc_factory = nullptr;
     }
 
@@ -836,11 +707,6 @@ void FileSystemController::CreateFactories(FileSys::VfsFilesystem& vfs, bool ove
                                        bis_factory->GetUserNANDContents());
     }
 
-    if (save_data_factory == nullptr) {
-        save_data_factory =
-            std::make_unique<FileSys::SaveDataFactory>(system, std::move(nand_directory));
-    }
-
     if (sdmc_factory == nullptr) {
         sdmc_factory = std::make_unique<FileSys::SDMCFactory>(std::move(sd_directory),
                                                               std::move(sd_load_directory));
@@ -849,12 +715,19 @@ void FileSystemController::CreateFactories(FileSys::VfsFilesystem& vfs, bool ove
     }
 }
 
+void FileSystemController::Reset() {
+    std::scoped_lock lk{registration_lock};
+    registrations.clear();
+}
+
 void LoopProcess(Core::System& system) {
     auto server_manager = std::make_unique<ServerManager>(system);
 
+    const auto FileSystemProxyFactory = [&] { return std::make_shared<FSP_SRV>(system); };
+
     server_manager->RegisterNamedService("fsp-ldr", std::make_shared<FSP_LDR>(system));
     server_manager->RegisterNamedService("fsp:pr", std::make_shared<FSP_PR>(system));
-    server_manager->RegisterNamedService("fsp-srv", std::make_shared<FSP_SRV>(system));
+    server_manager->RegisterNamedService("fsp-srv", std::move(FileSystemProxyFactory));
     ServerManager::RunServer(std::move(server_manager));
 }
 
diff --git a/src/core/hle/service/filesystem/filesystem.h b/src/core/hle/service/filesystem/filesystem.h
index 276d264e1..48f37d289 100644
--- a/src/core/hle/service/filesystem/filesystem.h
+++ b/src/core/hle/service/filesystem/filesystem.h
@@ -43,6 +43,9 @@ class ServiceManager;
 
 namespace FileSystem {
 
+class RomFsController;
+class SaveDataController;
+
 enum class ContentStorageId : u32 {
     System,
     User,
@@ -61,32 +64,24 @@ enum class OpenDirectoryMode : u64 {
 };
 DECLARE_ENUM_FLAG_OPERATORS(OpenDirectoryMode);
 
+using ProcessId = u64;
+using ProgramId = u64;
+
 class FileSystemController {
 public:
     explicit FileSystemController(Core::System& system_);
     ~FileSystemController();
 
-    Result RegisterRomFS(std::unique_ptr<FileSys::RomFSFactory>&& factory);
-    Result RegisterSaveData(std::unique_ptr<FileSys::SaveDataFactory>&& factory);
-    Result RegisterSDMC(std::unique_ptr<FileSys::SDMCFactory>&& factory);
-    Result RegisterBIS(std::unique_ptr<FileSys::BISFactory>&& factory);
-
-    void SetPackedUpdate(FileSys::VirtualFile update_raw);
-    FileSys::VirtualFile OpenRomFSCurrentProcess() const;
-    FileSys::VirtualFile OpenPatchedRomFS(u64 title_id, FileSys::ContentRecordType type) const;
-    FileSys::VirtualFile OpenPatchedRomFSWithProgramIndex(u64 title_id, u8 program_index,
-                                                          FileSys::ContentRecordType type) const;
-    FileSys::VirtualFile OpenRomFS(u64 title_id, FileSys::StorageId storage_id,
-                                   FileSys::ContentRecordType type) const;
-    std::shared_ptr<FileSys::NCA> OpenBaseNca(u64 title_id, FileSys::StorageId storage_id,
-                                              FileSys::ContentRecordType type) const;
-
-    Result CreateSaveData(FileSys::VirtualDir* out_save_data, FileSys::SaveDataSpaceId space,
-                          const FileSys::SaveDataAttribute& save_struct) const;
-    Result OpenSaveData(FileSys::VirtualDir* out_save_data, FileSys::SaveDataSpaceId space,
-                        const FileSys::SaveDataAttribute& save_struct) const;
-    Result OpenSaveDataSpace(FileSys::VirtualDir* out_save_data_space,
-                             FileSys::SaveDataSpaceId space) const;
+    Result RegisterProcess(ProcessId process_id, ProgramId program_id,
+                           std::shared_ptr<FileSys::RomFSFactory>&& factory);
+    Result OpenProcess(ProgramId* out_program_id,
+                       std::shared_ptr<SaveDataController>* out_save_data_controller,
+                       std::shared_ptr<RomFsController>* out_romfs_controller,
+                       ProcessId process_id);
+    void SetPackedUpdate(ProcessId process_id, FileSys::VirtualFile update_raw);
+
+    std::shared_ptr<SaveDataController> OpenSaveDataController();
+
     Result OpenSDMC(FileSys::VirtualDir* out_sdmc) const;
     Result OpenBISPartition(FileSys::VirtualDir* out_bis_partition,
                             FileSys::BisPartitionId id) const;
@@ -96,11 +91,6 @@ public:
     u64 GetFreeSpaceSize(FileSys::StorageId id) const;
     u64 GetTotalSpaceSize(FileSys::StorageId id) const;
 
-    FileSys::SaveDataSize ReadSaveDataSize(FileSys::SaveDataType type, u64 title_id,
-                                           u128 user_id) const;
-    void WriteSaveDataSize(FileSys::SaveDataType type, u64 title_id, u128 user_id,
-                           FileSys::SaveDataSize new_value) const;
-
     void SetGameCard(FileSys::VirtualFile file);
     FileSys::XCI* GetGameCard() const;
 
@@ -133,15 +123,24 @@ public:
 
     FileSys::VirtualDir GetBCATDirectory(u64 title_id) const;
 
-    void SetAutoSaveDataCreation(bool enable);
-
     // Creates the SaveData, SDMC, and BIS Factories. Should be called once and before any function
     // above is called.
     void CreateFactories(FileSys::VfsFilesystem& vfs, bool overwrite = true);
 
+    void Reset();
+
 private:
-    std::unique_ptr<FileSys::RomFSFactory> romfs_factory;
-    std::unique_ptr<FileSys::SaveDataFactory> save_data_factory;
+    std::shared_ptr<FileSys::SaveDataFactory> CreateSaveDataFactory(ProgramId program_id);
+
+    struct Registration {
+        ProgramId program_id;
+        std::shared_ptr<FileSys::RomFSFactory> romfs_factory;
+        std::shared_ptr<FileSys::SaveDataFactory> save_data_factory;
+    };
+
+    std::mutex registration_lock;
+    std::map<ProcessId, Registration> registrations;
+
     std::unique_ptr<FileSys::SDMCFactory> sdmc_factory;
     std::unique_ptr<FileSys::BISFactory> bis_factory;
 
diff --git a/src/core/hle/service/filesystem/fsp_srv.cpp b/src/core/hle/service/filesystem/fsp_srv.cpp
index 82ecc1b90..a2397bec4 100644
--- a/src/core/hle/service/filesystem/fsp_srv.cpp
+++ b/src/core/hle/service/filesystem/fsp_srv.cpp
@@ -27,6 +27,8 @@
 #include "core/hle/result.h"
 #include "core/hle/service/filesystem/filesystem.h"
 #include "core/hle/service/filesystem/fsp_srv.h"
+#include "core/hle/service/filesystem/romfs_controller.h"
+#include "core/hle/service/filesystem/save_data_controller.h"
 #include "core/hle/service/hle_ipc.h"
 #include "core/hle/service/ipc_helpers.h"
 #include "core/reporter.h"
@@ -577,9 +579,11 @@ private:
 
 class ISaveDataInfoReader final : public ServiceFramework<ISaveDataInfoReader> {
 public:
-    explicit ISaveDataInfoReader(Core::System& system_, FileSys::SaveDataSpaceId space,
-                                 FileSystemController& fsc_)
-        : ServiceFramework{system_, "ISaveDataInfoReader"}, fsc{fsc_} {
+    explicit ISaveDataInfoReader(Core::System& system_,
+                                 std::shared_ptr<SaveDataController> save_data_controller_,
+                                 FileSys::SaveDataSpaceId space)
+        : ServiceFramework{system_, "ISaveDataInfoReader"}, save_data_controller{
+                                                                save_data_controller_} {
         static const FunctionInfo functions[] = {
             {0, &ISaveDataInfoReader::ReadSaveDataInfo, "ReadSaveDataInfo"},
         };
@@ -626,7 +630,7 @@ private:
 
     void FindAllSaves(FileSys::SaveDataSpaceId space) {
         FileSys::VirtualDir save_root{};
-        const auto result = fsc.OpenSaveDataSpace(&save_root, space);
+        const auto result = save_data_controller->OpenSaveDataSpace(&save_root, space);
 
         if (result != ResultSuccess || save_root == nullptr) {
             LOG_ERROR(Service_FS, "The save root for the space_id={:02X} was invalid!", space);
@@ -723,7 +727,8 @@ private:
     };
     static_assert(sizeof(SaveDataInfo) == 0x60, "SaveDataInfo has incorrect size.");
 
-    FileSystemController& fsc;
+    ProcessId process_id = 0;
+    std::shared_ptr<SaveDataController> save_data_controller;
     std::vector<SaveDataInfo> info;
     u64 next_entry_index = 0;
 };
@@ -863,21 +868,20 @@ FSP_SRV::FSP_SRV(Core::System& system_)
     if (Settings::values.enable_fs_access_log) {
         access_log_mode = AccessLogMode::SdCard;
     }
-
-    // This should be true on creation
-    fsc.SetAutoSaveDataCreation(true);
 }
 
 FSP_SRV::~FSP_SRV() = default;
 
 void FSP_SRV::SetCurrentProcess(HLERequestContext& ctx) {
-    IPC::RequestParser rp{ctx};
-    current_process_id = rp.Pop<u64>();
+    current_process_id = ctx.GetPID();
 
     LOG_DEBUG(Service_FS, "called. current_process_id=0x{:016X}", current_process_id);
 
+    const auto res =
+        fsc.OpenProcess(&program_id, &save_data_controller, &romfs_controller, current_process_id);
+
     IPC::ResponseBuilder rb{ctx, 2};
-    rb.Push(ResultSuccess);
+    rb.Push(res);
 }
 
 void FSP_SRV::OpenFileSystemWithPatch(HLERequestContext& ctx) {
@@ -916,7 +920,8 @@ void FSP_SRV::CreateSaveDataFileSystem(HLERequestContext& ctx) {
               uid[1], uid[0]);
 
     FileSys::VirtualDir save_data_dir{};
-    fsc.CreateSaveData(&save_data_dir, FileSys::SaveDataSpaceId::NandUser, save_struct);
+    save_data_controller->CreateSaveData(&save_data_dir, FileSys::SaveDataSpaceId::NandUser,
+                                         save_struct);
 
     IPC::ResponseBuilder rb{ctx, 2};
     rb.Push(ResultSuccess);
@@ -931,7 +936,8 @@ void FSP_SRV::CreateSaveDataFileSystemBySystemSaveDataId(HLERequestContext& ctx)
     LOG_DEBUG(Service_FS, "called save_struct = {}", save_struct.DebugInfo());
 
     FileSys::VirtualDir save_data_dir{};
-    fsc.CreateSaveData(&save_data_dir, FileSys::SaveDataSpaceId::NandSystem, save_struct);
+    save_data_controller->CreateSaveData(&save_data_dir, FileSys::SaveDataSpaceId::NandSystem,
+                                         save_struct);
 
     IPC::ResponseBuilder rb{ctx, 2};
     rb.Push(ResultSuccess);
@@ -950,7 +956,8 @@ void FSP_SRV::OpenSaveDataFileSystem(HLERequestContext& ctx) {
     LOG_INFO(Service_FS, "called.");
 
     FileSys::VirtualDir dir{};
-    auto result = fsc.OpenSaveData(&dir, parameters.space_id, parameters.attribute);
+    auto result =
+        save_data_controller->OpenSaveData(&dir, parameters.space_id, parameters.attribute);
     if (result != ResultSuccess) {
         IPC::ResponseBuilder rb{ctx, 2, 0, 0};
         rb.Push(FileSys::ERROR_ENTITY_NOT_FOUND);
@@ -1001,7 +1008,7 @@ void FSP_SRV::OpenSaveDataInfoReaderBySaveDataSpaceId(HLERequestContext& ctx) {
     IPC::ResponseBuilder rb{ctx, 2, 0, 1};
     rb.Push(ResultSuccess);
     rb.PushIpcInterface<ISaveDataInfoReader>(
-        std::make_shared<ISaveDataInfoReader>(system, space, fsc));
+        std::make_shared<ISaveDataInfoReader>(system, save_data_controller, space));
 }
 
 void FSP_SRV::OpenSaveDataInfoReaderOnlyCacheStorage(HLERequestContext& ctx) {
@@ -1009,8 +1016,8 @@ void FSP_SRV::OpenSaveDataInfoReaderOnlyCacheStorage(HLERequestContext& ctx) {
 
     IPC::ResponseBuilder rb{ctx, 2, 0, 1};
     rb.Push(ResultSuccess);
-    rb.PushIpcInterface<ISaveDataInfoReader>(system, FileSys::SaveDataSpaceId::TemporaryStorage,
-                                             fsc);
+    rb.PushIpcInterface<ISaveDataInfoReader>(system, save_data_controller,
+                                             FileSys::SaveDataSpaceId::TemporaryStorage);
 }
 
 void FSP_SRV::WriteSaveDataFileSystemExtraDataBySaveDataAttribute(HLERequestContext& ctx) {
@@ -1050,7 +1057,7 @@ void FSP_SRV::OpenDataStorageByCurrentProcess(HLERequestContext& ctx) {
     LOG_DEBUG(Service_FS, "called");
 
     if (!romfs) {
-        auto current_romfs = fsc.OpenRomFSCurrentProcess();
+        auto current_romfs = romfs_controller->OpenRomFSCurrentProcess();
         if (!current_romfs) {
             // TODO (bunnei): Find the right error code to use here
             LOG_CRITICAL(Service_FS, "no file system interface available!");
@@ -1078,7 +1085,7 @@ void FSP_SRV::OpenDataStorageByDataId(HLERequestContext& ctx) {
     LOG_DEBUG(Service_FS, "called with storage_id={:02X}, unknown={:08X}, title_id={:016X}",
               storage_id, unknown, title_id);
 
-    auto data = fsc.OpenRomFS(title_id, storage_id, FileSys::ContentRecordType::Data);
+    auto data = romfs_controller->OpenRomFS(title_id, storage_id, FileSys::ContentRecordType::Data);
 
     if (!data) {
         const auto archive = FileSys::SystemArchive::SynthesizeSystemArchive(title_id);
@@ -1101,7 +1108,8 @@ void FSP_SRV::OpenDataStorageByDataId(HLERequestContext& ctx) {
 
     const FileSys::PatchManager pm{title_id, fsc, content_provider};
 
-    auto base = fsc.OpenBaseNca(title_id, storage_id, FileSys::ContentRecordType::Data);
+    auto base =
+        romfs_controller->OpenBaseNca(title_id, storage_id, FileSys::ContentRecordType::Data);
     auto storage = std::make_shared<IStorage>(
         system, pm.PatchRomFS(base.get(), std::move(data), FileSys::ContentRecordType::Data));
 
@@ -1129,9 +1137,8 @@ void FSP_SRV::OpenDataStorageWithProgramIndex(HLERequestContext& ctx) {
 
     LOG_DEBUG(Service_FS, "called, program_index={}", program_index);
 
-    auto patched_romfs =
-        fsc.OpenPatchedRomFSWithProgramIndex(system.GetApplicationProcessProgramID(), program_index,
-                                             FileSys::ContentRecordType::Program);
+    auto patched_romfs = romfs_controller->OpenPatchedRomFSWithProgramIndex(
+        program_id, program_index, FileSys::ContentRecordType::Program);
 
     if (!patched_romfs) {
         // TODO: Find the right error code to use here
@@ -1152,7 +1159,7 @@ void FSP_SRV::OpenDataStorageWithProgramIndex(HLERequestContext& ctx) {
 void FSP_SRV::DisableAutoSaveDataCreation(HLERequestContext& ctx) {
     LOG_DEBUG(Service_FS, "called");
 
-    fsc.SetAutoSaveDataCreation(false);
+    save_data_controller->SetAutoCreate(false);
 
     IPC::ResponseBuilder rb{ctx, 2};
     rb.Push(ResultSuccess);
diff --git a/src/core/hle/service/filesystem/fsp_srv.h b/src/core/hle/service/filesystem/fsp_srv.h
index 280bc9867..26980af99 100644
--- a/src/core/hle/service/filesystem/fsp_srv.h
+++ b/src/core/hle/service/filesystem/fsp_srv.h
@@ -17,6 +17,9 @@ class FileSystemBackend;
 
 namespace Service::FileSystem {
 
+class RomFsController;
+class SaveDataController;
+
 enum class AccessLogVersion : u32 {
     V7_0_0 = 2,
 
@@ -67,6 +70,9 @@ private:
     u64 current_process_id = 0;
     u32 access_log_program_index = 0;
     AccessLogMode access_log_mode = AccessLogMode::None;
+    u64 program_id = 0;
+    std::shared_ptr<SaveDataController> save_data_controller;
+    std::shared_ptr<RomFsController> romfs_controller;
 };
 
 } // namespace Service::FileSystem
diff --git a/src/core/hle/service/filesystem/romfs_controller.cpp b/src/core/hle/service/filesystem/romfs_controller.cpp
new file mode 100644
index 000000000..19c9cec72
--- /dev/null
+++ b/src/core/hle/service/filesystem/romfs_controller.cpp
@@ -0,0 +1,37 @@
+// SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "core/hle/service/filesystem/romfs_controller.h"
+
+namespace Service::FileSystem {
+
+RomFsController::RomFsController(std::shared_ptr<FileSys::RomFSFactory> factory_, u64 program_id_)
+    : factory{std::move(factory_)}, program_id{program_id_} {}
+RomFsController::~RomFsController() = default;
+
+FileSys::VirtualFile RomFsController::OpenRomFSCurrentProcess() {
+    return factory->OpenCurrentProcess(program_id);
+}
+
+FileSys::VirtualFile RomFsController::OpenPatchedRomFS(u64 title_id,
+                                                       FileSys::ContentRecordType type) {
+    return factory->OpenPatchedRomFS(title_id, type);
+}
+
+FileSys::VirtualFile RomFsController::OpenPatchedRomFSWithProgramIndex(
+    u64 title_id, u8 program_index, FileSys::ContentRecordType type) {
+    return factory->OpenPatchedRomFSWithProgramIndex(title_id, program_index, type);
+}
+
+FileSys::VirtualFile RomFsController::OpenRomFS(u64 title_id, FileSys::StorageId storage_id,
+                                                FileSys::ContentRecordType type) {
+    return factory->Open(title_id, storage_id, type);
+}
+
+std::shared_ptr<FileSys::NCA> RomFsController::OpenBaseNca(u64 title_id,
+                                                           FileSys::StorageId storage_id,
+                                                           FileSys::ContentRecordType type) {
+    return factory->GetEntry(title_id, storage_id, type);
+}
+
+} // namespace Service::FileSystem
diff --git a/src/core/hle/service/filesystem/romfs_controller.h b/src/core/hle/service/filesystem/romfs_controller.h
new file mode 100644
index 000000000..9a478f71d
--- /dev/null
+++ b/src/core/hle/service/filesystem/romfs_controller.h
@@ -0,0 +1,31 @@
+// SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "core/file_sys/nca_metadata.h"
+#include "core/file_sys/romfs_factory.h"
+#include "core/file_sys/vfs_types.h"
+
+namespace Service::FileSystem {
+
+class RomFsController {
+public:
+    explicit RomFsController(std::shared_ptr<FileSys::RomFSFactory> factory_, u64 program_id_);
+    ~RomFsController();
+
+    FileSys::VirtualFile OpenRomFSCurrentProcess();
+    FileSys::VirtualFile OpenPatchedRomFS(u64 title_id, FileSys::ContentRecordType type);
+    FileSys::VirtualFile OpenPatchedRomFSWithProgramIndex(u64 title_id, u8 program_index,
+                                                          FileSys::ContentRecordType type);
+    FileSys::VirtualFile OpenRomFS(u64 title_id, FileSys::StorageId storage_id,
+                                   FileSys::ContentRecordType type);
+    std::shared_ptr<FileSys::NCA> OpenBaseNca(u64 title_id, FileSys::StorageId storage_id,
+                                              FileSys::ContentRecordType type);
+
+private:
+    const std::shared_ptr<FileSys::RomFSFactory> factory;
+    const u64 program_id;
+};
+
+} // namespace Service::FileSystem
diff --git a/src/core/hle/service/filesystem/save_data_controller.cpp b/src/core/hle/service/filesystem/save_data_controller.cpp
new file mode 100644
index 000000000..d19b3ea1e
--- /dev/null
+++ b/src/core/hle/service/filesystem/save_data_controller.cpp
@@ -0,0 +1,99 @@
+// SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#include "core/core.h"
+#include "core/file_sys/control_metadata.h"
+#include "core/file_sys/errors.h"
+#include "core/file_sys/patch_manager.h"
+#include "core/hle/service/filesystem/save_data_controller.h"
+#include "core/loader/loader.h"
+
+namespace Service::FileSystem {
+
+namespace {
+
+// A default size for normal/journal save data size if application control metadata cannot be found.
+// This should be large enough to satisfy even the most extreme requirements (~4.2GB)
+constexpr u64 SufficientSaveDataSize = 0xF0000000;
+
+FileSys::SaveDataSize GetDefaultSaveDataSize(Core::System& system, u64 program_id) {
+    const FileSys::PatchManager pm{program_id, system.GetFileSystemController(),
+                                   system.GetContentProvider()};
+    const auto metadata = pm.GetControlMetadata();
+    const auto& nacp = metadata.first;
+
+    if (nacp != nullptr) {
+        return {nacp->GetDefaultNormalSaveSize(), nacp->GetDefaultJournalSaveSize()};
+    }
+
+    return {SufficientSaveDataSize, SufficientSaveDataSize};
+}
+
+} // namespace
+
+SaveDataController::SaveDataController(Core::System& system_,
+                                       std::shared_ptr<FileSys::SaveDataFactory> factory_)
+    : system{system_}, factory{std::move(factory_)} {}
+SaveDataController::~SaveDataController() = default;
+
+Result SaveDataController::CreateSaveData(FileSys::VirtualDir* out_save_data,
+                                          FileSys::SaveDataSpaceId space,
+                                          const FileSys::SaveDataAttribute& attribute) {
+    LOG_TRACE(Service_FS, "Creating Save Data for space_id={:01X}, save_struct={}", space,
+              attribute.DebugInfo());
+
+    auto save_data = factory->Create(space, attribute);
+    if (save_data == nullptr) {
+        return FileSys::ERROR_ENTITY_NOT_FOUND;
+    }
+
+    *out_save_data = save_data;
+    return ResultSuccess;
+}
+
+Result SaveDataController::OpenSaveData(FileSys::VirtualDir* out_save_data,
+                                        FileSys::SaveDataSpaceId space,
+                                        const FileSys::SaveDataAttribute& attribute) {
+    auto save_data = factory->Open(space, attribute);
+    if (save_data == nullptr) {
+        return FileSys::ERROR_ENTITY_NOT_FOUND;
+    }
+
+    *out_save_data = save_data;
+    return ResultSuccess;
+}
+
+Result SaveDataController::OpenSaveDataSpace(FileSys::VirtualDir* out_save_data_space,
+                                             FileSys::SaveDataSpaceId space) {
+    auto save_data_space = factory->GetSaveDataSpaceDirectory(space);
+    if (save_data_space == nullptr) {
+        return FileSys::ERROR_ENTITY_NOT_FOUND;
+    }
+
+    *out_save_data_space = save_data_space;
+    return ResultSuccess;
+}
+
+FileSys::SaveDataSize SaveDataController::ReadSaveDataSize(FileSys::SaveDataType type, u64 title_id,
+                                                           u128 user_id) {
+    const auto value = factory->ReadSaveDataSize(type, title_id, user_id);
+
+    if (value.normal == 0 && value.journal == 0) {
+        const auto size = GetDefaultSaveDataSize(system, title_id);
+        factory->WriteSaveDataSize(type, title_id, user_id, size);
+        return size;
+    }
+
+    return value;
+}
+
+void SaveDataController::WriteSaveDataSize(FileSys::SaveDataType type, u64 title_id, u128 user_id,
+                                           FileSys::SaveDataSize new_value) {
+    factory->WriteSaveDataSize(type, title_id, user_id, new_value);
+}
+
+void SaveDataController::SetAutoCreate(bool state) {
+    factory->SetAutoCreate(state);
+}
+
+} // namespace Service::FileSystem
diff --git a/src/core/hle/service/filesystem/save_data_controller.h b/src/core/hle/service/filesystem/save_data_controller.h
new file mode 100644
index 000000000..863188e4c
--- /dev/null
+++ b/src/core/hle/service/filesystem/save_data_controller.h
@@ -0,0 +1,35 @@
+// SPDX-FileCopyrightText: Copyright 2024 yuzu Emulator Project
+// SPDX-License-Identifier: GPL-2.0-or-later
+
+#pragma once
+
+#include "core/file_sys/nca_metadata.h"
+#include "core/file_sys/savedata_factory.h"
+#include "core/file_sys/vfs_types.h"
+
+namespace Service::FileSystem {
+
+class SaveDataController {
+public:
+    explicit SaveDataController(Core::System& system,
+                                std::shared_ptr<FileSys::SaveDataFactory> factory_);
+    ~SaveDataController();
+
+    Result CreateSaveData(FileSys::VirtualDir* out_save_data, FileSys::SaveDataSpaceId space,
+                          const FileSys::SaveDataAttribute& attribute);
+    Result OpenSaveData(FileSys::VirtualDir* out_save_data, FileSys::SaveDataSpaceId space,
+                        const FileSys::SaveDataAttribute& attribute);
+    Result OpenSaveDataSpace(FileSys::VirtualDir* out_save_data_space,
+                             FileSys::SaveDataSpaceId space);
+
+    FileSys::SaveDataSize ReadSaveDataSize(FileSys::SaveDataType type, u64 title_id, u128 user_id);
+    void WriteSaveDataSize(FileSys::SaveDataType type, u64 title_id, u128 user_id,
+                           FileSys::SaveDataSize new_value);
+    void SetAutoCreate(bool state);
+
+private:
+    Core::System& system;
+    const std::shared_ptr<FileSys::SaveDataFactory> factory;
+};
+
+} // namespace Service::FileSystem
diff --git a/src/core/hle/service/glue/arp.cpp b/src/core/hle/service/glue/arp.cpp
index 6f1151b03..1254b6d49 100644
--- a/src/core/hle/service/glue/arp.cpp
+++ b/src/core/hle/service/glue/arp.cpp
@@ -15,9 +15,10 @@
 namespace Service::Glue {
 
 namespace {
-std::optional<u64> GetTitleIDForProcessID(const Core::System& system, u64 process_id) {
-    const auto& list = system.Kernel().GetProcessList();
-    const auto iter = std::find_if(list.begin(), list.end(), [&process_id](const auto& process) {
+std::optional<u64> GetTitleIDForProcessID(Core::System& system, u64 process_id) {
+    auto list = system.Kernel().GetProcessList();
+
+    const auto iter = std::find_if(list.begin(), list.end(), [&process_id](auto& process) {
         return process->GetProcessId() == process_id;
     });
 
diff --git a/src/core/hle/service/hid/hid.cpp b/src/core/hle/service/hid/hid.cpp
index fc03a0a5f..4ce0a9834 100644
--- a/src/core/hle/service/hid/hid.cpp
+++ b/src/core/hle/service/hid/hid.cpp
@@ -22,12 +22,10 @@ void LoopProcess(Core::System& system) {
     std::shared_ptr<HidFirmwareSettings> firmware_settings =
         std::make_shared<HidFirmwareSettings>();
 
-    // TODO: Remove this hack until this service is emulated properly.
-    const auto process_list = system.Kernel().GetProcessList();
-    if (!process_list.empty()) {
-        resource_manager->Initialize();
-        resource_manager->RegisterAppletResourceUserId(process_list[0]->GetId(), true);
-    }
+    // TODO: Remove this hack when am is emulated properly.
+    resource_manager->Initialize();
+    resource_manager->RegisterAppletResourceUserId(system.ApplicationProcess()->GetProcessId(),
+                                                   true);
 
     server_manager->RegisterNamedService(
         "hid", std::make_shared<IHidServer>(system, resource_manager, firmware_settings));
diff --git a/src/core/hle/service/hid/hid_server.cpp b/src/core/hle/service/hid/hid_server.cpp
index 74898888a..1951da33b 100644
--- a/src/core/hle/service/hid/hid_server.cpp
+++ b/src/core/hle/service/hid/hid_server.cpp
@@ -1498,7 +1498,7 @@ void IHidServer::GetVibrationDeviceInfo(HLERequestContext& ctx) {
     bool check_device_index = false;
 
     switch (vibration_device_handle.npad_type) {
-    case Core::HID::NpadStyleIndex::ProController:
+    case Core::HID::NpadStyleIndex::Fullkey:
     case Core::HID::NpadStyleIndex::Handheld:
     case Core::HID::NpadStyleIndex::JoyconDual:
     case Core::HID::NpadStyleIndex::JoyconLeft:
diff --git a/src/core/hle/service/nvnflinger/nvnflinger.cpp b/src/core/hle/service/nvnflinger/nvnflinger.cpp
index aa8aaa2d9..0469110e8 100644
--- a/src/core/hle/service/nvnflinger/nvnflinger.cpp
+++ b/src/core/hle/service/nvnflinger/nvnflinger.cpp
@@ -223,7 +223,8 @@ Result Nvnflinger::FindVsyncEvent(Kernel::KReadableEvent** out_vsync_event, u64
         return VI::ResultNotFound;
     }
 
-    return display->GetVSyncEvent(out_vsync_event);
+    *out_vsync_event = display->GetVSyncEvent();
+    return ResultSuccess;
 }
 
 VI::Display* Nvnflinger::FindDisplay(u64 display_id) {
diff --git a/src/core/hle/service/pm/pm.cpp b/src/core/hle/service/pm/pm.cpp
index d92499f05..b52468e41 100644
--- a/src/core/hle/service/pm/pm.cpp
+++ b/src/core/hle/service/pm/pm.cpp
@@ -22,27 +22,26 @@ constexpr Result ResultProcessNotFound{ErrorModule::PM, 1};
 
 constexpr u64 NO_PROCESS_FOUND_PID{0};
 
-std::optional<Kernel::KProcess*> SearchProcessList(
-    const std::vector<Kernel::KProcess*>& process_list,
-    std::function<bool(Kernel::KProcess*)> predicate) {
+using ProcessList = std::list<Kernel::KScopedAutoObject<Kernel::KProcess>>;
+
+template <typename F>
+Kernel::KScopedAutoObject<Kernel::KProcess> SearchProcessList(ProcessList& process_list,
+                                                              F&& predicate) {
     const auto iter = std::find_if(process_list.begin(), process_list.end(), predicate);
 
     if (iter == process_list.end()) {
-        return std::nullopt;
+        return nullptr;
     }
 
-    return *iter;
+    return iter->GetPointerUnsafe();
 }
 
-void GetApplicationPidGeneric(HLERequestContext& ctx,
-                              const std::vector<Kernel::KProcess*>& process_list) {
-    const auto process = SearchProcessList(process_list, [](const auto& proc) {
-        return proc->GetProcessId() == Kernel::KProcess::ProcessIdMin;
-    });
+void GetApplicationPidGeneric(HLERequestContext& ctx, ProcessList& process_list) {
+    auto process = SearchProcessList(process_list, [](auto& p) { return p->IsApplication(); });
 
     IPC::ResponseBuilder rb{ctx, 4};
     rb.Push(ResultSuccess);
-    rb.Push(process.has_value() ? (*process)->GetProcessId() : NO_PROCESS_FOUND_PID);
+    rb.Push(process.IsNull() ? NO_PROCESS_FOUND_PID : process->GetProcessId());
 }
 
 } // Anonymous namespace
@@ -80,8 +79,7 @@ private:
 
 class DebugMonitor final : public ServiceFramework<DebugMonitor> {
 public:
-    explicit DebugMonitor(Core::System& system_)
-        : ServiceFramework{system_, "pm:dmnt"}, kernel{system_.Kernel()} {
+    explicit DebugMonitor(Core::System& system_) : ServiceFramework{system_, "pm:dmnt"} {
         // clang-format off
         static const FunctionInfo functions[] = {
             {0, nullptr, "GetJitDebugProcessIdList"},
@@ -106,12 +104,11 @@ private:
 
         LOG_DEBUG(Service_PM, "called, program_id={:016X}", program_id);
 
-        const auto process =
-            SearchProcessList(kernel.GetProcessList(), [program_id](const auto& proc) {
-                return proc->GetProgramId() == program_id;
-            });
+        auto list = kernel.GetProcessList();
+        auto process = SearchProcessList(
+            list, [program_id](auto& p) { return p->GetProgramId() == program_id; });
 
-        if (!process.has_value()) {
+        if (process.IsNull()) {
             IPC::ResponseBuilder rb{ctx, 2};
             rb.Push(ResultProcessNotFound);
             return;
@@ -119,12 +116,13 @@ private:
 
         IPC::ResponseBuilder rb{ctx, 4};
         rb.Push(ResultSuccess);
-        rb.Push((*process)->GetProcessId());
+        rb.Push(process->GetProcessId());
     }
 
     void GetApplicationProcessId(HLERequestContext& ctx) {
         LOG_DEBUG(Service_PM, "called");
-        GetApplicationPidGeneric(ctx, kernel.GetProcessList());
+        auto list = kernel.GetProcessList();
+        GetApplicationPidGeneric(ctx, list);
     }
 
     void AtmosphereGetProcessInfo(HLERequestContext& ctx) {
@@ -135,11 +133,10 @@ private:
 
         LOG_WARNING(Service_PM, "(Partial Implementation) called, pid={:016X}", pid);
 
-        const auto process = SearchProcessList(kernel.GetProcessList(), [pid](const auto& proc) {
-            return proc->GetProcessId() == pid;
-        });
+        auto list = kernel.GetProcessList();
+        auto process = SearchProcessList(list, [pid](auto& p) { return p->GetProcessId() == pid; });
 
-        if (!process.has_value()) {
+        if (process.IsNull()) {
             IPC::ResponseBuilder rb{ctx, 2};
             rb.Push(ResultProcessNotFound);
             return;
@@ -159,7 +156,7 @@ private:
 
         OverrideStatus override_status{};
         ProgramLocation program_location{
-            .program_id = (*process)->GetProgramId(),
+            .program_id = process->GetProgramId(),
             .storage_id = 0,
         };
 
@@ -169,14 +166,11 @@ private:
         rb.PushRaw(program_location);
         rb.PushRaw(override_status);
     }
-
-    const Kernel::KernelCore& kernel;
 };
 
 class Info final : public ServiceFramework<Info> {
 public:
-    explicit Info(Core::System& system_, const std::vector<Kernel::KProcess*>& process_list_)
-        : ServiceFramework{system_, "pm:info"}, process_list{process_list_} {
+    explicit Info(Core::System& system_) : ServiceFramework{system_, "pm:info"} {
         static const FunctionInfo functions[] = {
             {0, &Info::GetProgramId, "GetProgramId"},
             {65000, &Info::AtmosphereGetProcessId, "AtmosphereGetProcessId"},
@@ -193,11 +187,11 @@ private:
 
         LOG_DEBUG(Service_PM, "called, process_id={:016X}", process_id);
 
-        const auto process = SearchProcessList(process_list, [process_id](const auto& proc) {
-            return proc->GetProcessId() == process_id;
-        });
+        auto list = kernel.GetProcessList();
+        auto process = SearchProcessList(
+            list, [process_id](auto& p) { return p->GetProcessId() == process_id; });
 
-        if (!process.has_value()) {
+        if (process.IsNull()) {
             IPC::ResponseBuilder rb{ctx, 2};
             rb.Push(ResultProcessNotFound);
             return;
@@ -205,7 +199,7 @@ private:
 
         IPC::ResponseBuilder rb{ctx, 4};
         rb.Push(ResultSuccess);
-        rb.Push((*process)->GetProgramId());
+        rb.Push(process->GetProgramId());
     }
 
     void AtmosphereGetProcessId(HLERequestContext& ctx) {
@@ -214,11 +208,11 @@ private:
 
         LOG_DEBUG(Service_PM, "called, program_id={:016X}", program_id);
 
-        const auto process = SearchProcessList(process_list, [program_id](const auto& proc) {
-            return proc->GetProgramId() == program_id;
-        });
+        auto list = system.Kernel().GetProcessList();
+        auto process = SearchProcessList(
+            list, [program_id](auto& p) { return p->GetProgramId() == program_id; });
 
-        if (!process.has_value()) {
+        if (process.IsNull()) {
             IPC::ResponseBuilder rb{ctx, 2};
             rb.Push(ResultProcessNotFound);
             return;
@@ -226,16 +220,13 @@ private:
 
         IPC::ResponseBuilder rb{ctx, 4};
         rb.Push(ResultSuccess);
-        rb.Push((*process)->GetProcessId());
+        rb.Push(process->GetProcessId());
     }
-
-    const std::vector<Kernel::KProcess*>& process_list;
 };
 
 class Shell final : public ServiceFramework<Shell> {
 public:
-    explicit Shell(Core::System& system_)
-        : ServiceFramework{system_, "pm:shell"}, kernel{system_.Kernel()} {
+    explicit Shell(Core::System& system_) : ServiceFramework{system_, "pm:shell"} {
         // clang-format off
         static const FunctionInfo functions[] = {
             {0, nullptr, "LaunchProgram"},
@@ -257,10 +248,9 @@ public:
 private:
     void GetApplicationProcessIdForShell(HLERequestContext& ctx) {
         LOG_DEBUG(Service_PM, "called");
-        GetApplicationPidGeneric(ctx, kernel.GetProcessList());
+        auto list = kernel.GetProcessList();
+        GetApplicationPidGeneric(ctx, list);
     }
-
-    const Kernel::KernelCore& kernel;
 };
 
 void LoopProcess(Core::System& system) {
@@ -268,8 +258,7 @@ void LoopProcess(Core::System& system) {
 
     server_manager->RegisterNamedService("pm:bm", std::make_shared<BootMode>(system));
     server_manager->RegisterNamedService("pm:dmnt", std::make_shared<DebugMonitor>(system));
-    server_manager->RegisterNamedService(
-        "pm:info", std::make_shared<Info>(system, system.Kernel().GetProcessList()));
+    server_manager->RegisterNamedService("pm:info", std::make_shared<Info>(system));
     server_manager->RegisterNamedService("pm:shell", std::make_shared<Shell>(system));
     ServerManager::RunServer(std::move(server_manager));
 }
diff --git a/src/core/hle/service/server_manager.cpp b/src/core/hle/service/server_manager.cpp
index 15edb23e0..8ef49387d 100644
--- a/src/core/hle/service/server_manager.cpp
+++ b/src/core/hle/service/server_manager.cpp
@@ -256,8 +256,13 @@ Result ServerManager::WaitAndProcessImpl() {
 
         // Wait for a signal.
         s32 out_index{-1};
-        R_TRY(Kernel::KSynchronizationObject::Wait(m_system.Kernel(), &out_index, wait_objs.data(),
-                                                   num_objs, -1));
+        R_TRY_CATCH(Kernel::KSynchronizationObject::Wait(m_system.Kernel(), &out_index,
+                                                         wait_objs.data(), num_objs, -1)) {
+            R_CATCH(Kernel::ResultSessionClosed) {
+                // On session closed, index is updated and we don't want to return an error.
+            }
+        }
+        R_END_TRY_CATCH;
         ASSERT(out_index >= 0 && out_index < num_objs);
 
         // Set the output index.
diff --git a/src/core/hle/service/vi/display/vi_display.cpp b/src/core/hle/service/vi/display/vi_display.cpp
index 71ce9be50..e2d9cd98a 100644
--- a/src/core/hle/service/vi/display/vi_display.cpp
+++ b/src/core/hle/service/vi/display/vi_display.cpp
@@ -71,18 +71,7 @@ size_t Display::GetNumLayers() const {
     return std::ranges::count_if(layers, [](auto& l) { return l->IsOpen(); });
 }
 
-Result Display::GetVSyncEvent(Kernel::KReadableEvent** out_vsync_event) {
-    if (got_vsync_event) {
-        return ResultPermissionDenied;
-    }
-
-    got_vsync_event = true;
-
-    *out_vsync_event = GetVSyncEventUnchecked();
-    return ResultSuccess;
-}
-
-Kernel::KReadableEvent* Display::GetVSyncEventUnchecked() {
+Kernel::KReadableEvent* Display::GetVSyncEvent() {
     return &vsync_event->GetReadableEvent();
 }
 
diff --git a/src/core/hle/service/vi/display/vi_display.h b/src/core/hle/service/vi/display/vi_display.h
index 1d9360b96..7e68ee79b 100644
--- a/src/core/hle/service/vi/display/vi_display.h
+++ b/src/core/hle/service/vi/display/vi_display.h
@@ -74,16 +74,8 @@ public:
 
     std::size_t GetNumLayers() const;
 
-    /**
-     * Gets the internal vsync event.
-     *
-     * @returns The internal Vsync event if it has not yet been retrieved,
-     *          VI::ResultPermissionDenied otherwise.
-     */
-    [[nodiscard]] Result GetVSyncEvent(Kernel::KReadableEvent** out_vsync_event);
-
     /// Gets the internal vsync event.
-    Kernel::KReadableEvent* GetVSyncEventUnchecked();
+    Kernel::KReadableEvent* GetVSyncEvent();
 
     /// Signals the internal vsync event.
     void SignalVSyncEvent();
@@ -104,7 +96,6 @@ public:
     /// Resets the display for a new connection.
     void Reset() {
         layers.clear();
-        got_vsync_event = false;
     }
 
     /// Attempts to find a layer with the given ID.
@@ -133,7 +124,6 @@ private:
 
     std::vector<std::unique_ptr<Layer>> layers;
     Kernel::KEvent* vsync_event{};
-    bool got_vsync_event{false};
 };
 
 } // namespace Service::VI
diff --git a/src/core/hle/service/vi/vi.cpp b/src/core/hle/service/vi/vi.cpp
index 9ab8788e3..39d5be90d 100644
--- a/src/core/hle/service/vi/vi.cpp
+++ b/src/core/hle/service/vi/vi.cpp
@@ -343,8 +343,8 @@ private:
 
 class IManagerDisplayService final : public ServiceFramework<IManagerDisplayService> {
 public:
-    explicit IManagerDisplayService(Core::System& system_, Nvnflinger::Nvnflinger& nv_flinger_)
-        : ServiceFramework{system_, "IManagerDisplayService"}, nv_flinger{nv_flinger_} {
+    explicit IManagerDisplayService(Core::System& system_, Nvnflinger::Nvnflinger& nvnflinger_)
+        : ServiceFramework{system_, "IManagerDisplayService"}, nvnflinger{nvnflinger_} {
         // clang-format off
         static const FunctionInfo functions[] = {
             {200, nullptr, "AllocateProcessHeapBlock"},
@@ -440,7 +440,7 @@ private:
         IPC::RequestParser rp{ctx};
         const u64 display = rp.Pop<u64>();
 
-        const Result rc = nv_flinger.CloseDisplay(display) ? ResultSuccess : ResultUnknown;
+        const Result rc = nvnflinger.CloseDisplay(display) ? ResultSuccess : ResultUnknown;
 
         IPC::ResponseBuilder rb{ctx, 2};
         rb.Push(rc);
@@ -457,7 +457,7 @@ private:
                     "(STUBBED) called. unknown=0x{:08X}, display=0x{:016X}, aruid=0x{:016X}",
                     unknown, display, aruid);
 
-        const auto layer_id = nv_flinger.CreateLayer(display);
+        const auto layer_id = nvnflinger.CreateLayer(display);
         if (!layer_id) {
             LOG_ERROR(Service_VI, "Layer not found! display=0x{:016X}", display);
             IPC::ResponseBuilder rb{ctx, 2};
@@ -494,14 +494,14 @@ private:
         rb.Push(ResultSuccess);
     }
 
-    Nvnflinger::Nvnflinger& nv_flinger;
+    Nvnflinger::Nvnflinger& nvnflinger;
 };
 
 class IApplicationDisplayService final : public ServiceFramework<IApplicationDisplayService> {
 public:
-    IApplicationDisplayService(Core::System& system_, Nvnflinger::Nvnflinger& nv_flinger_,
+    IApplicationDisplayService(Core::System& system_, Nvnflinger::Nvnflinger& nvnflinger_,
                                Nvnflinger::HosBinderDriverServer& hos_binder_driver_server_)
-        : ServiceFramework{system_, "IApplicationDisplayService"}, nv_flinger{nv_flinger_},
+        : ServiceFramework{system_, "IApplicationDisplayService"}, nvnflinger{nvnflinger_},
           hos_binder_driver_server{hos_binder_driver_server_} {
 
         static const FunctionInfo functions[] = {
@@ -564,7 +564,7 @@ private:
 
         IPC::ResponseBuilder rb{ctx, 2, 0, 1};
         rb.Push(ResultSuccess);
-        rb.PushIpcInterface<ISystemDisplayService>(system, nv_flinger);
+        rb.PushIpcInterface<ISystemDisplayService>(system, nvnflinger);
     }
 
     void GetManagerDisplayService(HLERequestContext& ctx) {
@@ -572,7 +572,7 @@ private:
 
         IPC::ResponseBuilder rb{ctx, 2, 0, 1};
         rb.Push(ResultSuccess);
-        rb.PushIpcInterface<IManagerDisplayService>(system, nv_flinger);
+        rb.PushIpcInterface<IManagerDisplayService>(system, nvnflinger);
     }
 
     void GetIndirectDisplayTransactionService(HLERequestContext& ctx) {
@@ -607,7 +607,7 @@ private:
 
         ASSERT_MSG(name == "Default", "Non-default displays aren't supported yet");
 
-        const auto display_id = nv_flinger.OpenDisplay(name);
+        const auto display_id = nvnflinger.OpenDisplay(name);
         if (!display_id) {
             LOG_ERROR(Service_VI, "Display not found! display_name={}", name);
             IPC::ResponseBuilder rb{ctx, 2};
@@ -624,7 +624,7 @@ private:
         IPC::RequestParser rp{ctx};
         const u64 display_id = rp.Pop<u64>();
 
-        const Result rc = nv_flinger.CloseDisplay(display_id) ? ResultSuccess : ResultUnknown;
+        const Result rc = nvnflinger.CloseDisplay(display_id) ? ResultSuccess : ResultUnknown;
 
         IPC::ResponseBuilder rb{ctx, 2};
         rb.Push(rc);
@@ -703,7 +703,7 @@ private:
 
         LOG_DEBUG(Service_VI, "called. layer_id=0x{:016X}, aruid=0x{:016X}", layer_id, aruid);
 
-        const auto display_id = nv_flinger.OpenDisplay(display_name);
+        const auto display_id = nvnflinger.OpenDisplay(display_name);
         if (!display_id) {
             LOG_ERROR(Service_VI, "Layer not found! layer_id={}", layer_id);
             IPC::ResponseBuilder rb{ctx, 2};
@@ -711,7 +711,7 @@ private:
             return;
         }
 
-        const auto buffer_queue_id = nv_flinger.FindBufferQueueId(*display_id, layer_id);
+        const auto buffer_queue_id = nvnflinger.FindBufferQueueId(*display_id, layer_id);
         if (!buffer_queue_id) {
             LOG_ERROR(Service_VI, "Buffer queue id not found! display_id={}", *display_id);
             IPC::ResponseBuilder rb{ctx, 2};
@@ -719,7 +719,7 @@ private:
             return;
         }
 
-        nv_flinger.OpenLayer(layer_id);
+        nvnflinger.OpenLayer(layer_id);
 
         android::OutputParcel parcel;
         parcel.WriteInterface(NativeWindow{*buffer_queue_id});
@@ -737,7 +737,7 @@ private:
 
         LOG_DEBUG(Service_VI, "called. layer_id=0x{:016X}", layer_id);
 
-        nv_flinger.CloseLayer(layer_id);
+        nvnflinger.CloseLayer(layer_id);
 
         IPC::ResponseBuilder rb{ctx, 2};
         rb.Push(ResultSuccess);
@@ -753,7 +753,7 @@ private:
 
         // TODO(Subv): What's the difference between a Stray and a Managed layer?
 
-        const auto layer_id = nv_flinger.CreateLayer(display_id);
+        const auto layer_id = nvnflinger.CreateLayer(display_id);
         if (!layer_id) {
             LOG_ERROR(Service_VI, "Layer not found! display_id={}", display_id);
             IPC::ResponseBuilder rb{ctx, 2};
@@ -761,7 +761,7 @@ private:
             return;
         }
 
-        const auto buffer_queue_id = nv_flinger.FindBufferQueueId(display_id, *layer_id);
+        const auto buffer_queue_id = nvnflinger.FindBufferQueueId(display_id, *layer_id);
         if (!buffer_queue_id) {
             LOG_ERROR(Service_VI, "Buffer queue id not found! display_id={}", display_id);
             IPC::ResponseBuilder rb{ctx, 2};
@@ -785,7 +785,7 @@ private:
         const u64 layer_id = rp.Pop<u64>();
 
         LOG_WARNING(Service_VI, "(STUBBED) called. layer_id=0x{:016X}", layer_id);
-        nv_flinger.DestroyLayer(layer_id);
+        nvnflinger.DestroyLayer(layer_id);
 
         IPC::ResponseBuilder rb{ctx, 2};
         rb.Push(ResultSuccess);
@@ -798,7 +798,7 @@ private:
         LOG_DEBUG(Service_VI, "called. display_id={}", display_id);
 
         Kernel::KReadableEvent* vsync_event{};
-        const auto result = nv_flinger.FindVsyncEvent(&vsync_event, display_id);
+        const auto result = nvnflinger.FindVsyncEvent(&vsync_event, display_id);
         if (result != ResultSuccess) {
             if (result == ResultNotFound) {
                 LOG_ERROR(Service_VI, "Vsync event was not found for display_id={}", display_id);
@@ -808,6 +808,12 @@ private:
             rb.Push(result);
             return;
         }
+        if (vsync_event_fetched) {
+            IPC::ResponseBuilder rb{ctx, 2};
+            rb.Push(VI::ResultPermissionDenied);
+            return;
+        }
+        vsync_event_fetched = true;
 
         IPC::ResponseBuilder rb{ctx, 2, 1};
         rb.Push(ResultSuccess);
@@ -899,8 +905,9 @@ private:
         }
     }
 
-    Nvnflinger::Nvnflinger& nv_flinger;
+    Nvnflinger::Nvnflinger& nvnflinger;
     Nvnflinger::HosBinderDriverServer& hos_binder_driver_server;
+    bool vsync_event_fetched{false};
 };
 
 static bool IsValidServiceAccess(Permission permission, Policy policy) {
@@ -916,7 +923,7 @@ static bool IsValidServiceAccess(Permission permission, Policy policy) {
 }
 
 void detail::GetDisplayServiceImpl(HLERequestContext& ctx, Core::System& system,
-                                   Nvnflinger::Nvnflinger& nv_flinger,
+                                   Nvnflinger::Nvnflinger& nvnflinger,
                                    Nvnflinger::HosBinderDriverServer& hos_binder_driver_server,
                                    Permission permission) {
     IPC::RequestParser rp{ctx};
@@ -931,19 +938,19 @@ void detail::GetDisplayServiceImpl(HLERequestContext& ctx, Core::System& system,
 
     IPC::ResponseBuilder rb{ctx, 2, 0, 1};
     rb.Push(ResultSuccess);
-    rb.PushIpcInterface<IApplicationDisplayService>(system, nv_flinger, hos_binder_driver_server);
+    rb.PushIpcInterface<IApplicationDisplayService>(system, nvnflinger, hos_binder_driver_server);
 }
 
-void LoopProcess(Core::System& system, Nvnflinger::Nvnflinger& nv_flinger,
+void LoopProcess(Core::System& system, Nvnflinger::Nvnflinger& nvnflinger,
                  Nvnflinger::HosBinderDriverServer& hos_binder_driver_server) {
     auto server_manager = std::make_unique<ServerManager>(system);
 
     server_manager->RegisterNamedService(
-        "vi:m", std::make_shared<VI_M>(system, nv_flinger, hos_binder_driver_server));
+        "vi:m", std::make_shared<VI_M>(system, nvnflinger, hos_binder_driver_server));
     server_manager->RegisterNamedService(
-        "vi:s", std::make_shared<VI_S>(system, nv_flinger, hos_binder_driver_server));
+        "vi:s", std::make_shared<VI_S>(system, nvnflinger, hos_binder_driver_server));
     server_manager->RegisterNamedService(
-        "vi:u", std::make_shared<VI_U>(system, nv_flinger, hos_binder_driver_server));
+        "vi:u", std::make_shared<VI_U>(system, nvnflinger, hos_binder_driver_server));
     ServerManager::RunServer(std::move(server_manager));
 }
 
diff --git a/src/core/hle/service/vi/vi.h b/src/core/hle/service/vi/vi.h
index a35b62f97..ee4bcbcfa 100644
--- a/src/core/hle/service/vi/vi.h
+++ b/src/core/hle/service/vi/vi.h
@@ -48,7 +48,7 @@ void GetDisplayServiceImpl(HLERequestContext& ctx, Core::System& system,
                            Permission permission);
 } // namespace detail
 
-void LoopProcess(Core::System& system, Nvnflinger::Nvnflinger& nv_flinger,
+void LoopProcess(Core::System& system, Nvnflinger::Nvnflinger& nvnflinger,
                  Nvnflinger::HosBinderDriverServer& hos_binder_driver_server);
 
 } // namespace Service::VI