[Qemu-devel] [PATCH 2/2] input: introduce keyboard handler list

[Gerd Hoffmann <kraxel@redhat.com>]

Add a linked list of keyboard handlers.  Added handlers will go
to the head of the list.  Removed handlers will be zapped from
the list.  The head of the list will be used for events.

This fixes the keyboard-dead-after-usb-kbd-unplug issue, key events
will be re-routed to the ps/2 kbd instead of being discarded.

[ v2: fix cut+paste bug found my Markus ]

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
---
 hw/input/hid.c         |    4 ++--
 include/hw/input/hid.h |    1 +
 include/ui/console.h   |    6 ++++--
 ui/input.c             |   37 +++++++++++++++++++++++++------------
 4 files changed, 32 insertions(+), 16 deletions(-)

diff --git a/hw/input/hid.c b/hw/input/hid.c
index 5fbde98..14b3125 100644
--- a/hw/input/hid.c
+++ b/hw/input/hid.c
@@ -415,7 +415,7 @@ void hid_free(HIDState *hs)
 {
     switch (hs->kind) {
     case HID_KEYBOARD:
-        qemu_remove_kbd_event_handler();
+        qemu_remove_kbd_event_handler(hs->kbd.eh_entry);
         break;
     case HID_MOUSE:
     case HID_TABLET:
@@ -431,7 +431,7 @@ void hid_init(HIDState *hs, int kind, HIDEventFunc event)
     hs->event = event;
 
     if (hs->kind == HID_KEYBOARD) {
-        qemu_add_kbd_event_handler(hid_keyboard_event, hs);
+        hs->kbd.eh_entry = qemu_add_kbd_event_handler(hid_keyboard_event, hs);
     } else if (hs->kind == HID_MOUSE) {
         hs->ptr.eh_entry = qemu_add_mouse_event_handler(hid_pointer_event, hs,
                                                         0, "QEMU HID Mouse");
diff --git a/include/hw/input/hid.h b/include/hw/input/hid.h
index 56c71ed..2567879 100644
--- a/include/hw/input/hid.h
+++ b/include/hw/input/hid.h
@@ -31,6 +31,7 @@ typedef struct HIDKeyboardState {
     uint8_t leds;
     uint8_t key[16];
     int32_t keys;
+    QEMUPutKbdEntry *eh_entry;
 } HIDKeyboardState;
 
 struct HIDState {
diff --git a/include/ui/console.h b/include/ui/console.h
index 5cc5d0c..1c82f51 100644
--- a/include/ui/console.h
+++ b/include/ui/console.h
@@ -29,10 +29,12 @@ typedef void QEMUPutLEDEvent(void *opaque, int ledstate);
 typedef void QEMUPutMouseEvent(void *opaque, int dx, int dy, int dz, int buttons_state);
 
 typedef struct QEMUPutMouseEntry QEMUPutMouseEntry;
+typedef struct QEMUPutKbdEntry QEMUPutKbdEntry;
 typedef struct QEMUPutLEDEntry QEMUPutLEDEntry;
 
-void qemu_add_kbd_event_handler(QEMUPutKBDEvent *func, void *opaque);
-void qemu_remove_kbd_event_handler(void);
+QEMUPutKbdEntry *qemu_add_kbd_event_handler(QEMUPutKBDEvent *func,
+                                            void *opaque);
+void qemu_remove_kbd_event_handler(QEMUPutKbdEntry *entry);
 QEMUPutMouseEntry *qemu_add_mouse_event_handler(QEMUPutMouseEvent *func,
                                                 void *opaque, int absolute,
                                                 const char *name);
diff --git a/ui/input.c b/ui/input.c
index d8793e7..8ca1a03 100644
--- a/ui/input.c
+++ b/ui/input.c
@@ -41,18 +41,25 @@ struct QEMUPutMouseEntry {
     QTAILQ_ENTRY(QEMUPutMouseEntry) node;
 };
 
+struct QEMUPutKbdEntry {
+    QEMUPutKBDEvent *put_kbd;
+    void *opaque;
+    QTAILQ_ENTRY(QEMUPutKbdEntry) next;
+};
+
 struct QEMUPutLEDEntry {
     QEMUPutLEDEvent *put_led;
     void *opaque;
     QTAILQ_ENTRY(QEMUPutLEDEntry) next;
 };
 
-static QEMUPutKBDEvent *qemu_put_kbd_event;
-static void *qemu_put_kbd_event_opaque;
-static QTAILQ_HEAD(, QEMUPutLEDEntry) led_handlers = QTAILQ_HEAD_INITIALIZER(led_handlers);
+static QTAILQ_HEAD(, QEMUPutLEDEntry) led_handlers =
+    QTAILQ_HEAD_INITIALIZER(led_handlers);
+static QTAILQ_HEAD(, QEMUPutKbdEntry) kbd_handlers =
+    QTAILQ_HEAD_INITIALIZER(kbd_handlers);
 static QTAILQ_HEAD(, QEMUPutMouseEntry) mouse_handlers =
     QTAILQ_HEAD_INITIALIZER(mouse_handlers);
-static NotifierList mouse_mode_notifiers = 
+static NotifierList mouse_mode_notifiers =
     NOTIFIER_LIST_INITIALIZER(mouse_mode_notifiers);
 
 static const int key_defs[] = {
@@ -304,16 +311,20 @@ void qmp_send_key(KeyValueList *keys, bool has_hold_time, int64_t hold_time,
                    muldiv64(get_ticks_per_sec(), hold_time, 1000));
 }
 
-void qemu_add_kbd_event_handler(QEMUPutKBDEvent *func, void *opaque)
+QEMUPutKbdEntry *qemu_add_kbd_event_handler(QEMUPutKBDEvent *func, void *opaque)
 {
-    qemu_put_kbd_event_opaque = opaque;
-    qemu_put_kbd_event = func;
+    QEMUPutKbdEntry *entry;
+
+    entry = g_malloc0(sizeof(QEMUPutKbdEntry));
+    entry->put_kbd = func;
+    entry->opaque = opaque;
+    QTAILQ_INSERT_HEAD(&kbd_handlers, entry, next);
+    return entry;
 }
 
-void qemu_remove_kbd_event_handler(void)
+void qemu_remove_kbd_event_handler(QEMUPutKbdEntry *entry)
 {
-    qemu_put_kbd_event_opaque = NULL;
-    qemu_put_kbd_event = NULL;
+    QTAILQ_REMOVE(&kbd_handlers, entry, next);
 }
 
 static void check_mode_change(void)
@@ -397,11 +408,13 @@ void qemu_remove_led_event_handler(QEMUPutLEDEntry *entry)
 
 void kbd_put_keycode(int keycode)
 {
+    QEMUPutKbdEntry *entry = QTAILQ_FIRST(&kbd_handlers);
+
     if (!runstate_is_running() && !runstate_check(RUN_STATE_SUSPENDED)) {
         return;
     }
-    if (qemu_put_kbd_event) {
-        qemu_put_kbd_event(qemu_put_kbd_event_opaque, keycode);
+    if (entry) {
+        entry->put_kbd(entry->opaque, keycode);
     }
 }
 
-- 
1.7.9.7