[PATCH 08/13] char: Add mux option to ChardevOptions

[Kevin Wolf <kwolf@redhat.com>]

The final missing piece to achieve compatibility between
qemu_chr_parse_cli_str()/qemu_chr_new_cli() and the legacy command line
is support for the 'mux' option. Implement it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 qapi/char.json |  4 +++-
 chardev/char.c | 41 +++++++++++++++++++++++++++++++++++------
 2 files changed, 38 insertions(+), 7 deletions(-)

diff --git a/qapi/char.json b/qapi/char.json
index e1f9347044..d6733a5473 100644
--- a/qapi/char.json
+++ b/qapi/char.json
@@ -453,12 +453,14 @@
 #
 # @id: the chardev's ID, must be unique
 # @backend: backend type and parameters
+# @mux: enable multiplexing mode (default: false)
 #
 # Since: 6.0
 ##
 { 'struct': 'ChardevOptions',
   'data': { 'id': 'str',
-            'backend': 'ChardevBackend' },
+            'backend': 'ChardevBackend',
+            '*mux': 'bool' },
   'aliases': [ { 'source': ['backend'] } ] }
 
 ##
diff --git a/chardev/char.c b/chardev/char.c
index a5d6be9dc8..3bb6a743f7 100644
--- a/chardev/char.c
+++ b/chardev/char.c
@@ -742,11 +742,6 @@ void qemu_chr_translate_legacy_options(QDict *args)
 
     /* name may refer to a QDict entry, so delete it only now */
     qdict_del(args, "backend");
-
-    /*
-     * TODO:
-     * All backend types: "mux"
-     */
 }
 
 Chardev *qemu_chr_new_noreplay(const char *label, const char *filename,
@@ -1105,7 +1100,41 @@ ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
 
 Chardev *qemu_chr_new_cli(ChardevOptions *options, Error **errp)
 {
-    return chardev_new_qapi(options->id, options->backend, errp);
+    Chardev *chr;
+    char *bid = NULL;
+
+    if (options->mux) {
+        bid = g_strdup_printf("%s-base", options->id);
+    }
+
+    chr = chardev_new_qapi(bid ?: options->id, options->backend, errp);
+    if (!chr) {
+        goto out;
+    }
+
+    if (options->mux) {
+        Chardev *mux;
+        ChardevMux mux_data = {
+            .chardev = bid,
+        };
+        ChardevBackend backend = {
+            .type = CHARDEV_BACKEND_KIND_MUX,
+            .u.mux.data = &mux_data,
+        };
+
+        mux = qemu_chardev_new(options->id, TYPE_CHARDEV_MUX, &backend, NULL,
+                               errp);
+        if (mux == NULL) {
+            object_unparent(OBJECT(chr));
+            chr = NULL;
+            goto out;
+        }
+        chr = mux;
+    }
+
+out:
+    g_free(bid);
+    return chr;
 }
 
 ChardevOptions *qemu_chr_parse_cli_dict(QDict *args, bool help,
-- 
2.28.0