qmp: qmp_send_key(): accept key codes in hex

Before the qapi conversion, the sendkey command could be used to
send key codes in hex directly to the guest. In HMP, this would
be like:

 (qemu) sendkey 0xdc

However, the qapi conversion broke this, as it only supports sending
QKeyCode values to the guest. That's a regression.

This commit fixes the problem by adding hex value support down
the QMP interface, qmp_send_key().

In more detail, this commit:

 1. Adds the KeyValue union. This can represent an hex value or
    a QKeyCode value

 2. *Changes* the QMP send-key command to take an KeyValue argument
    instead of a QKeyCode one

 3. Adapt hmp_send_key() to the QMP interface changes

Item 2 is an incompatible change, but as we're in development phase
(and this command has been merged a few weeks ago) this shouldn't be
a problem.

Finally, it's not possible to split this commit without breaking the
build.

Reported-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>

hmp.c

@@ -1113,13 +1113,13 @@ void hmp_closefd(Monitor *mon, const QDict *qdict)
 void hmp_send_key(Monitor *mon, const QDict *qdict)
 {
     const char *keys = qdict_get_str(qdict, "keys");
-    QKeyCodeList *keylist, *head = NULL, *tmp = NULL;
+    KeyValueList *keylist, *head = NULL, *tmp = NULL;
     int has_hold_time = qdict_haskey(qdict, "hold-time");
     int hold_time = qdict_get_try_int(qdict, "hold-time", -1);
     Error *err = NULL;
     char keyname_buf[16];
     char *separator;
-    int keyname_len, idx;
+    int keyname_len;
 
     while (1) {
         separator = strchr(keys, '-');
@@ -1133,15 +1133,8 @@ void hmp_send_key(Monitor *mon, const QDict *qdict)
         }
         keyname_buf[keyname_len] = 0;
 
-        idx = index_from_key(keyname_buf);
-        if (idx == Q_KEY_CODE_MAX) {
-            monitor_printf(mon, "invalid parameter: %s\n", keyname_buf);
-            break;
-        }
-
         keylist = g_malloc0(sizeof(*keylist));
-        keylist->value = idx;
-        keylist->next = NULL;
+        keylist->value = g_malloc0(sizeof(*keylist->value));
 
         if (!head) {
             head = keylist;
@@ -1151,17 +1144,39 @@ void hmp_send_key(Monitor *mon, const QDict *qdict)
         }
         tmp = keylist;
 
+        if (strstart(keyname_buf, "0x", NULL)) {
+            char *endp;
+            int value = strtoul(keyname_buf, &endp, 0);
+            if (*endp != '\0') {
+                goto err_out;
+            }
+            keylist->value->kind = KEY_VALUE_KIND_NUMBER;
+            keylist->value->number = value;
+        } else {
+            int idx = index_from_key(keyname_buf);
+            if (idx == Q_KEY_CODE_MAX) {
+                goto err_out;
+            }
+            keylist->value->kind = KEY_VALUE_KIND_QCODE;
+            keylist->value->qcode = idx;
+        }
+
         if (!separator) {
             break;
         }
         keys = separator + 1;
     }
 
-    if (idx != Q_KEY_CODE_MAX) {
-        qmp_send_key(head, has_hold_time, hold_time, &err);
-    }
+    qmp_send_key(head, has_hold_time, hold_time, &err);
     hmp_handle_error(mon, &err);
-    qapi_free_QKeyCodeList(head);
+
+out:
+    qapi_free_KeyValueList(head);
+    return;
+
+err_out:
+    monitor_printf(mon, "invalid parameter: %s\n", keyname_buf);
+    goto out;
 }
 
 void hmp_screen_dump(Monitor *mon, const QDict *qdict)

input.c

@@ -228,6 +228,23 @@ static int *keycodes;
 static int keycodes_size;
 static QEMUTimer *key_timer;
 
+static int keycode_from_keyvalue(const KeyValue *value)
+{
+    if (value->kind == KEY_VALUE_KIND_QCODE) {
+        return key_defs[value->qcode];
+    } else {
+        assert(value->kind == KEY_VALUE_KIND_NUMBER);
+        return value->number;
+    }
+}
+
+static void free_keycodes(void)
+{
+    g_free(keycodes);
+    keycodes = NULL;
+    keycodes_size = 0;
+}
+
 static void release_keys(void *opaque)
 {
     int i;
@@ -239,16 +256,14 @@ static void release_keys(void *opaque)
         kbd_put_keycode(keycodes[i]| 0x80);
     }
 
-    g_free(keycodes);
-    keycodes = NULL;
-    keycodes_size = 0;
+    free_keycodes();
 }
 
-void qmp_send_key(QKeyCodeList *keys, bool has_hold_time, int64_t hold_time,
+void qmp_send_key(KeyValueList *keys, bool has_hold_time, int64_t hold_time,
                   Error **errp)
 {
     int keycode;
-    QKeyCodeList *p;
+    KeyValueList *p;
 
     if (!key_timer) {
         key_timer = qemu_new_timer_ns(vm_clock, release_keys, NULL);
@@ -265,7 +280,13 @@ void qmp_send_key(QKeyCodeList *keys, bool has_hold_time, int64_t hold_time,
 
     for (p = keys; p != NULL; p = p->next) {
         /* key down events */
-        keycode = key_defs[p->value];
+        keycode = keycode_from_keyvalue(p->value);
+        if (keycode < 0x01 || keycode > 0xff) {
+            error_setg(errp, "invalid hex keycode 0x%x\n", keycode);
+            free_keycodes();
+            return;
+        }
+
         if (keycode & 0x80) {
             kbd_put_keycode(0xe0);
         }

qapi-schema.json

@@ -2620,13 +2620,27 @@
             'props', 'undo', 'front', 'copy', 'open', 'paste', 'find', 'cut',
              'lf', 'help', 'meta_l', 'meta_r', 'compose' ] }
 
+##
+# @KeyValue
+#
+# Represents a keyboard key.
+#
+# Since: 1.3.0
+##
+{ 'union': 'KeyValue',
+  'data': {
+    'number': 'int',
+    'qcode': 'QKeyCode' } }
+
 ##
 # @send-key:
 #
 # Send keys to guest.
 #
-# @keys: key sequence. 'keys' is the name of the key. Use a JSON array to
-#        press several keys simultaneously.
+# @keys: An array of @KeyValue elements. All @KeyValues in this array are
+#        simultaneously sent to the guest. A @KeyValue.number value is sent
+#        directly to the guest, while @KeyValue.qcode must be a valid
+#        @QKeyCode value
 #
 # @hold-time: #optional time to delay key up events, milliseconds. Defaults
 #             to 100
@@ -2638,7 +2652,7 @@
 #
 ##
 { 'command': 'send-key',
-  'data': { 'keys': ['QKeyCode'], '*hold-time': 'int' } }
+  'data': { 'keys': ['KeyValue'], '*hold-time': 'int' } }
 
 ##
 # @screendump: