HMCL/src/main/java/org/jackhuang/hmcl/game/LauncherHelper.java

@@ -22,6 +22,7 @@ import org.jackhuang.hmcl.setting.JavaVersionType;
 import org.jackhuang.hmcl.setting.LauncherVisibility;
 import org.jackhuang.hmcl.task.*;
 import org.jackhuang.hmcl.ui.*;
+import org.jackhuang.hmcl.ui.instances.Instances;
 import org.jackhuang.hmcl.ui.construct.DialogCloseEvent;
 import org.jackhuang.hmcl.ui.construct.MessageDialogPane.MessageType;
 import org.jackhuang.hmcl.ui.construct.MessageDialogPane;
@@ -255,32 +256,12 @@ public final class LauncherHelper {
                     }
 
                     if (OperatingSystem.CURRENT_OS == OperatingSystem.WINDOWS && setting.getInheritable(GameSettings::highPerformanceProperty)) {
-                        @Nullable String javaPathGpuReg = FileUtils.getAbsolutePath(context.javaExecutable);
-                        try {
-                            WinReg reg = WinReg.INSTANCE;
-                            if (reg != null) {
-                                Object current = reg.queryValue(
-                                        WinReg.HKEY.HKEY_CURRENT_USER,
-                                        "Software\\Microsoft\\DirectX\\UserGpuPreferences",
-                                        javaPathGpuReg
-                                );
-                                if (current == null) {
-                                    boolean result = reg.setValue(
-                                            WinReg.HKEY.HKEY_CURRENT_USER,
-                                            "Software\\Microsoft\\DirectX\\UserGpuPreferences",
-                                            javaPathGpuReg,
-                                            "GpuPreference=2;"
-                                    );
-                                    if (result)
-                                        LOG.info("Successfully applied high performance GPU preference for java: " + javaPathGpuReg);
-                                    else
-                                        LOG.warning("Failed to apply high performance GPU preference for java: " + javaPathGpuReg);
-                                } else {
-                                    LOG.info("GPU preference for %s already exists: %s".formatted(javaPathGpuReg, current));
-                                }
-                            }
-                        } catch (Exception e) {
-                            LOG.warning("Failed to apply high performance GPU preference", e);
+                        // Register both java.exe and javaw.exe: the game may be started through either one.
+                        applyHighPerformanceGpuPreference(context.javaExecutable);
+                        Path sibling = context.javaExecutable.resolveSibling(
+                                FileUtils.getName(context.javaExecutable).equalsIgnoreCase("javaw.exe") ? "java.exe" : "javaw.exe");
+                        if (Files.isRegularFile(sibling)) {
+                            applyHighPerformanceGpuPreference(sibling);
                         }
                     }
 
@@ -1048,11 +1029,44 @@ public final class LauncherHelper {
                 runLater(() -> new GameCrashWindow(process, exitType, gameInstance, launchOptions, logs).show());
             }
 
+            if (exitType == ExitType.NORMAL) {
+                // The game asked to be restarted (hot update): offer to update and relaunch.
+                String restartReason = RestartRequest.consume(gameInstance.getRunDirectory());
+                if (restartReason != null) {
+                    LOG.info("Game requested a restart, reason: " + restartReason);
+                    runLater(() -> Instances.offerRestart(gameInstance, restartReason));
+                }
+            }
+
             checkExit();
         }
 
     }
 
+    /// Asks Windows to run `executable` on the high-performance GPU (`GpuPreference=2`) unless the user
+    /// already has a preference stored for it.
+    private static void applyHighPerformanceGpuPreference(Path executable) {
+        String path = FileUtils.getAbsolutePath(executable);
+        try {
+            WinReg reg = WinReg.INSTANCE;
+            if (reg == null) {
+                return;
+            }
+            Object current = reg.queryValue(WinReg.HKEY.HKEY_CURRENT_USER,
+                    "Software\\Microsoft\\DirectX\\UserGpuPreferences", path);
+            if (current != null) {
+                LOG.info("GPU preference for %s already exists: %s".formatted(path, current));
+            } else if (reg.setValue(WinReg.HKEY.HKEY_CURRENT_USER,
+                    "Software\\Microsoft\\DirectX\\UserGpuPreferences", path, "GpuPreference=2;")) {
+                LOG.info("Successfully applied high performance GPU preference for java: " + path);
+            } else {
+                LOG.warning("Failed to apply high performance GPU preference for java: " + path);
+            }
+        } catch (Exception e) {
+            LOG.warning("Failed to apply high performance GPU preference", e);
+        }
+    }
+
     private static final Queue<WeakReference<ManagedProcess>> PROCESSES = new ConcurrentLinkedQueue<>();
 
     public static int countMangedProcesses() {

HMCL/src/main/java/org/jackhuang/hmcl/game/RestartRequest.java

@@ -0,0 +1,56 @@
+// SPDX-FileCopyrightText: Copyright (C) 2026 The HMCL Authors
+// SPDX-License-Identifier: GPL-3.0-or-later WITH AdditionRef-HMCL
+package org.jackhuang.hmcl.game;
+
+import com.google.gson.JsonObject;
+import org.jackhuang.hmcl.util.gson.JsonUtils;
+import org.jetbrains.annotations.NotNullByDefault;
+import org.jetbrains.annotations.Nullable;
+
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+/// The "please restart me" handshake between the game and the launcher.
+///
+/// When the game wants to be restarted (for example after a hot update), it writes
+/// [#FILE_NAME] into its run directory as `{"reason":"update"}` and exits normally. After the
+/// process ends the launcher calls [#consume(Path)], deletes the file and offers to update and relaunch.
+@NotNullByDefault
+public final class RestartRequest {
+    private RestartRequest() {
+    }
+
+    /// The marker file name inside the game's run directory.
+    public static final String FILE_NAME = "tdlm-restart-request.json";
+
+    /// Reads and deletes the restart request in `runDirectory`.
+    ///
+    /// A malformed file still counts as a request with reason `"unknown"`, because the file's presence is
+    /// the signal. The file is always removed so a request cannot trigger twice.
+    ///
+    /// @param runDirectory the game's run directory
+    /// @return the reason, or `null` if no request was pending
+    public static @Nullable String consume(Path runDirectory) {
+        Path file = runDirectory.resolve(FILE_NAME);
+        if (!Files.isRegularFile(file)) {
+            return null;
+        }
+        String reason = "unknown";
+        try {
+            JsonObject object = JsonUtils.GSON.fromJson(Files.readString(file, StandardCharsets.UTF_8), JsonObject.class);
+            if (object != null && object.has("reason") && object.get("reason").isJsonPrimitive()) {
+                reason = object.get("reason").getAsString();
+            }
+        } catch (IOException | RuntimeException ignored) {
+            // The presence of the file is the signal; keep the default reason.
+        }
+        try {
+            Files.deleteIfExists(file);
+        } catch (IOException ignored) {
+            // Nothing sensible to do; the worst case is one more prompt on the next exit.
+        }
+        return reason;
+    }
+}

HMCL/src/main/java/org/jackhuang/hmcl/setting/GameSettings.java

@@ -645,9 +645,12 @@ public sealed abstract class GameSettings extends ObservableSetting {
     public static final String PROPERTY_HIGH_PERFORMANCE = "highPerformance";
 
     /// Whether to launch games with high-performance GPU.
+    ///
+    /// On by default: on a laptop with an integrated and a discrete GPU, Windows otherwise picks the
+    /// integrated one for java. Machines with a single GPU are unaffected by the preference.
     @SerializedName(PROPERTY_HIGH_PERFORMANCE)
     private final InheritableProperty<Boolean> highPerformance =
-            newInheritableProperty(PROPERTY_HIGH_PERFORMANCE, false);
+            newInheritableProperty(PROPERTY_HIGH_PERFORMANCE, true);
 
     /// Returns the high performance GPU preference property.
     public InheritableProperty<Boolean> highPerformanceProperty() {

HMCL/src/main/java/org/jackhuang/hmcl/ui/instances/Instances.java

@@ -398,6 +398,21 @@ public final class Instances {
                         .addQuestion(new PromptDialogPane.Builder.BooleanQuestion(i18n("instance.manage.duplicate.duplicate_save"), false)));
     }
 
+    /// Asks whether to update and relaunch after the game requested a restart (see [RestartRequest]).
+    ///
+    /// Yes runs the Start flow, which syncs the client pack and joins the server again; No leaves the
+    /// launcher as it is. The request file is already deleted, so the prompt shows only once.
+    ///
+    /// @param gameInstance the instance that just exited
+    /// @param reason       the reason from the request file, for example `update`
+    public static void offerRestart(HMCLGameInstance gameInstance, String reason) {
+        Controllers.confirm(
+                i18n("home.restart." + ("update".equals(reason) ? "update" : "generic")),
+                i18n("home.restart.title"),
+                () -> updateInstance(gameInstance),
+                null);
+    }
+
     /// Updates via fileApi through the Start flow — no install wizard.
     public static void updateInstance(HMCLGameInstance gameInstance) {
         gameInstance.getRepository().setSelectedInstance(gameInstance);

HMCL/src/main/java/org/jackhuang/hmcl/ui/main/MainPage.java

@@ -136,7 +136,19 @@ public final class MainPage extends StackPane implements DecoratorPage {
         card.getStyleClass().add("home-card");
         card.setAlignment(Pos.CENTER_LEFT);
         card.setMaxHeight(Region.USE_PREF_SIZE);
-        StackPane.setAlignment(card, Pos.BOTTOM_CENTER);
+        // Server announcement (the server's MOTD), shown above the card only when there is one.
+        Label motdLabel = new Label();
+        motdLabel.getStyleClass().add("home-subtitle");
+        motdLabel.setWrapText(true);
+        motdLabel.setMaxHeight(Region.USE_PREF_SIZE);
+        Label motdTitle = factLabel(i18n("home.motd"));
+        VBox motdBox = new VBox(3, motdTitle, motdLabel);
+        motdBox.setPadding(new Insets(0, 0, 14, 4));
+        motdBox.setVisible(false);
+        motdBox.setManaged(false);
+        VBox bottom = new VBox(motdBox, card);
+        bottom.setMaxHeight(Region.USE_PREF_SIZE);
+        StackPane.setAlignment(bottom, Pos.BOTTOM_CENTER);
 
         // Start always installs/updates from fileApi then joins — never opens install or instance UI.
         FXUtils.setOnActionWithCooldown(joinButton, MainPage.this::launch);
@@ -157,7 +169,7 @@ public final class MainPage extends StackPane implements DecoratorPage {
                 routeFact.setVisible(route != null);
                 routeFact.setManaged(route != null);
                 routeValue.setText(route != null ? route.name() : "");
-                refreshServerStatus(route, serverFact, serverValue);
+                refreshServerStatus(route, serverFact, serverValue, motdBox, motdLabel);
 
                 // With more than one route (for example direct and CDN), the route can be switched.
                 List<ServerEndpoint.Route> routes = ServerEndpoint.routes(currentGame.getModpackConfigurationFile());
@@ -174,7 +186,7 @@ public final class MainPage extends StackPane implements DecoratorPage {
                         items.add(new IconedMenuItem(null, candidate.name(), () -> {
                             ServerEndpoint.select(currentGame.getModpackConfigurationFile(), candidate);
                             routeValue.setText(candidate.name() + " ▾");
-                            refreshServerStatus(candidate, serverFact, serverValue);
+                            refreshServerStatus(candidate, serverFact, serverValue, motdBox, motdLabel);
                         }, popup));
                     }
                     list.getContent().setAll(items);
@@ -183,7 +195,7 @@ public final class MainPage extends StackPane implements DecoratorPage {
             }
         });
 
-        getChildren().addAll(art, hero, card);
+        getChildren().addAll(art, hero, bottom);
     }
 
     /// Sets the home button to install / update / join based on the selected instance and remote manifest.
@@ -208,26 +220,39 @@ public final class MainPage extends StackPane implements DecoratorPage {
     /// Pings the server behind `route` in the background and shows the result in `serverValue`.
     ///
     /// WebSocket routes cannot be pinged with plain TCP, so the status is hidden for them.
-    private static void refreshServerStatus(ServerEndpoint.@Nullable Route route, Node serverFact, Label serverValue) {
+    private static void refreshServerStatus(ServerEndpoint.@Nullable Route route, Node serverFact, Label serverValue,
+                                            Node motdBox, Label motdLabel) {
         String address = route == null ? "" : route.address().trim();
         boolean pingable = !address.isEmpty() && !address.toLowerCase(java.util.Locale.ROOT).startsWith("ws");
         serverFact.setVisible(pingable);
         serverFact.setManaged(pingable);
+        motdBox.setVisible(false);
+        motdBox.setManaged(false);
         if (!pingable) {
             return;
         }
         serverValue.setText("…");
         Schedulers.io().execute(() -> {
             String text;
+            String motd = "";
             try {
                 ServerAddress parsed = ServerAddress.parse(address);
                 ServerStatusPing.Status status = ServerStatusPing.ping(parsed.host(), parsed.port() >= 0 ? parsed.port() : 25565, 3000);
                 text = status.online() + " / " + status.max() + " · " + status.latencyMillis() + " ms";
+                motd = status.motd();
             } catch (IOException | IllegalArgumentException e) {
                 text = i18n("home.server.unreachable");
             }
             String result = text;
-            FXUtils.runInFX(() -> serverValue.setText(result));
+            String announcement = motd;
+            FXUtils.runInFX(() -> {
+                serverValue.setText(result);
+                // Unreachable or empty MOTD: stay silent, the announcement area stays hidden.
+                boolean show = !announcement.isEmpty();
+                motdLabel.setText(announcement);
+                motdBox.setVisible(show);
+                motdBox.setManaged(show);
+            });
         });
     }
 

HMCL/src/main/resources/assets/lang/I18N.properties

@@ -808,6 +808,10 @@ first_run.microsoft=Sign in with Microsoft
 first_run.invalid=Use 1 to 16 letters, digits or underscores.
 home.server=Server
 home.server.unreachable=Unreachable
+home.motd=Server announcement
+home.restart.title=Restart game
+home.restart.update=The game closed to apply an update. Update the client and start it again now?
+home.restart.generic=The game asked to be restarted. Update the client and start it again now?
 server.join=Join Server
 server.update=Update
 instance.launch_and_enter_world=Play World

HMCL/src/main/resources/assets/lang/I18N_lzh.properties

@@ -628,6 +628,10 @@ first_run.microsoft=登正版
 first_run.invalid=一至十六字，限英文數字底綫。
 home.server=服
 home.server.unreachable=不通
+home.motd=服公告
+home.restart.title=重啟遊戲
+home.restart.update=遊戲爲更新而止。今更新並重啟乎？
+home.restart.generic=遊戲請重啟。今更新並重啟乎？
 server.join=入服
 server.update=更新
 # instance.launch_and_enter_world=

HMCL/src/main/resources/assets/lang/I18N_zh_Hans.properties

@@ -631,6 +631,10 @@ first_run.microsoft=登录正版账号
 first_run.invalid=只能用 1 到 16 个英文字母、数字或下划线。
 home.server=服务器
 home.server.unreachable=连接不上
+home.motd=服务器公告
+home.restart.title=重启游戏
+home.restart.update=游戏为应用更新已退出。现在更新客户端并重新启动游戏吗？
+home.restart.generic=游戏请求重启。现在更新客户端并重新启动吗？
 server.join=进入服务器
 server.update=更新
 instance.launch_and_enter_world=进入世界

HMCL/src/main/resources/assets/lang/I18N_zh_Hant.properties

@@ -625,6 +625,10 @@ first_run.microsoft=登入正版帳號
 first_run.invalid=只能使用 1 到 16 個英文字母、數字或底線。
 home.server=伺服器
 home.server.unreachable=無法連線
+home.motd=伺服器公告
+home.restart.title=重啟遊戲
+home.restart.update=遊戲為套用更新已結束。現在更新客戶端並重新啟動遊戲嗎？
+home.restart.generic=遊戲要求重啟。現在更新客戶端並重新啟動嗎？
 server.join=進入伺服器
 server.update=更新
 instance.launch_and_enter_world=進入世界

HMCL/src/test/java/org/jackhuang/hmcl/game/RestartRequestTest.java

@@ -0,0 +1,36 @@
+// SPDX-FileCopyrightText: Copyright (C) 2026 The HMCL Authors
+// SPDX-License-Identifier: GPL-3.0-or-later WITH AdditionRef-HMCL
+package org.jackhuang.hmcl.game;
+
+import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.io.TempDir;
+
+import java.nio.file.Files;
+import java.nio.file.Path;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+/// Tests [RestartRequest].
+public final class RestartRequestTest {
+    @Test
+    void noFileMeansNoRequest(@TempDir Path dir) {
+        assertNull(RestartRequest.consume(dir));
+    }
+
+    @Test
+    void readsReasonAndDeletesFile(@TempDir Path dir) throws Exception {
+        Path file = dir.resolve(RestartRequest.FILE_NAME);
+        Files.writeString(file, "{\"reason\":\"update\"}");
+        assertEquals("update", RestartRequest.consume(dir));
+        assertFalse(Files.exists(file));
+        assertNull(RestartRequest.consume(dir));
+    }
+
+    @Test
+    void malformedFileStillCounts(@TempDir Path dir) throws Exception {
+        Path file = dir.resolve(RestartRequest.FILE_NAME);
+        Files.writeString(file, "not json");
+        assertEquals("unknown", RestartRequest.consume(dir));
+        assertFalse(Files.exists(file));
+    }
+}

HMCLCore/src/main/java/org/jackhuang/hmcl/launch/DefaultLauncher.java

@@ -799,6 +799,10 @@ public class DefaultLauncher extends Launcher {
                             env.put("__NV_PRIME_RENDER_OFFLOAD", "1");
                             env.put("__GLX_VENDOR_LIBRARY_NAME", "nvidia");
                             env.put("__VK_LAYER_NV_optimus", "NVIDIA_only");
+                        } else if (HardwareVendor.AMD.equals(discreteGraphicsCard.getVendor())
+                                || HardwareVendor.NVIDIA.equals(discreteGraphicsCard.getVendor())) {
+                            // Mesa PRIME offload (open source AMD / nouveau drivers)
+                            env.put("DRI_PRIME", "1");
                         }
                     }
                 }

HMCLCore/src/main/java/org/jackhuang/hmcl/util/ServerStatusPing.java

@@ -2,10 +2,12 @@
 // SPDX-License-Identifier: GPL-3.0-or-later WITH AdditionRef-HMCL
 package org.jackhuang.hmcl.util;
 
+import com.google.gson.JsonElement;
 import com.google.gson.JsonObject;
 import com.google.gson.JsonParseException;
 import org.jackhuang.hmcl.util.gson.JsonUtils;
 import org.jetbrains.annotations.NotNullByDefault;
+import org.jetbrains.annotations.Nullable;
 
 import java.io.ByteArrayOutputStream;
 import java.io.DataInputStream;
@@ -28,7 +30,40 @@ public final class ServerStatusPing {
     /// @param online        the number of players online
     /// @param max           the player limit
     /// @param latencyMillis the round-trip time of the ping packet in milliseconds
-    public record Status(int online, int max, long latencyMillis) {
+    /// @param motd          the server's message of the day as plain text without colour codes; empty if absent
+    public record Status(int online, int max, long latencyMillis, String motd) {
+        /// Creates a status without a message of the day.
+        public Status(int online, int max, long latencyMillis) {
+            this(online, max, latencyMillis, "");
+        }
+    }
+
+    /// Flattens the `description` field of a status response (a plain string or a chat component with
+    /// `text` and `extra`) into plain text, dropping `§x` colour and format codes.
+    ///
+    /// @param description the `description` element, may be `null`
+    /// @return the plain text, trimmed; empty when there is nothing to show
+    public static String motdToPlainText(@Nullable JsonElement description) {
+        StringBuilder builder = new StringBuilder();
+        appendComponent(description, builder);
+        return builder.toString().replaceAll("\u00a7.", "").strip();
+    }
+
+    private static void appendComponent(@Nullable JsonElement element, StringBuilder out) {
+        if (element == null || element.isJsonNull()) {
+            return;
+        }
+        if (element.isJsonPrimitive()) {
+            out.append(element.getAsString());
+        } else if (element.isJsonArray()) {
+            for (JsonElement item : element.getAsJsonArray()) {
+                appendComponent(item, out);
+            }
+        } else if (element.isJsonObject()) {
+            JsonObject object = element.getAsJsonObject();
+            appendComponent(object.get("text"), out);
+            appendComponent(object.get("extra"), out);
+        }
     }
 
     /// The protocol number sent in the handshake; Minecraft 1.7.10 uses 5 and servers answer any value.
@@ -73,9 +108,11 @@ public final class ServerStatusPing {
             in.readFully(json);
             int online;
             int max;
+            String motd;
             try {
-                JsonObject players = JsonUtils.GSON.fromJson(new String(json, StandardCharsets.UTF_8), JsonObject.class)
-                        .getAsJsonObject("players");
+                JsonObject response = JsonUtils.GSON.fromJson(new String(json, StandardCharsets.UTF_8), JsonObject.class);
+                motd = motdToPlainText(response.get("description"));
+                JsonObject players = response.getAsJsonObject("players");
                 online = players.get("online").getAsInt();
                 max = players.get("max").getAsInt();
             } catch (JsonParseException | NullPointerException | ClassCastException | IllegalStateException e) {
@@ -94,7 +131,7 @@ public final class ServerStatusPing {
                 throw new IOException("Unexpected pong packet");
             }
             in.readLong();
-            return new Status(online, max, (System.nanoTime() - start) / 1_000_000);
+            return new Status(online, max, (System.nanoTime() - start) / 1_000_000, motd);
         }
     }
 

HMCLCore/src/test/java/org/jackhuang/hmcl/util/ServerStatusPingTest.java

@@ -25,6 +25,7 @@ public final class ServerStatusPingTest {
             var status = ServerStatusPing.ping("127.0.0.1", server.getLocalPort(), 3000);
             assertEquals(12, status.online());
             assertEquals(50, status.max());
+            assertEquals("TDLM 公告: 今晚维护", status.motd());
             assertTrue(status.latencyMillis() >= 0);
         }
     }
@@ -45,7 +46,7 @@ public final class ServerStatusPingTest {
             skipPacket(in); // handshake
             skipPacket(in); // status request
 
-            byte[] json = "{\"players\":{\"online\":12,\"max\":50}}".getBytes(StandardCharsets.UTF_8);
+            byte[] json = "{\"description\":{\"text\":\"§aTDLM \",\"extra\":[{\"text\":\"公告: 今晚维护\"}]},\"players\":{\"online\":12,\"max\":50}}".getBytes(StandardCharsets.UTF_8);
             byte[] body = concat(new byte[]{0x00}, varInt(json.length), json);
             out.write(varInt(body.length));
             out.write(body);
@@ -88,4 +89,11 @@ public final class ServerStatusPingTest {
         for (byte[] part : parts) out.writeBytes(part);
         return out.toByteArray();
     }
+
+    @Test
+    void flattensPlainStringMotd() {
+        var json = com.google.gson.JsonParser.parseString("\"§l欢迎§r来玩\"");
+        assertEquals("欢迎来玩", ServerStatusPing.motdToPlainText(json));
+        assertEquals("", ServerStatusPing.motdToPlainText(null));
+    }
 }