[PATCH v3 4/7] chardev/char: introduce `mux-be-id=ID` option

[Roman Penyaev <r.peniaev@gmail.com>]

Patch introduces `mux-be-id=ID` option for all chardev devices.
This is necessary to attach chardev to `mux-be` for backend
multiplexing. Actual implementation wimplementation will follow.

Signed-off-by: Roman Penyaev <r.peniaev@gmail.com>
Cc: "Marc-André Lureau" <marcandre.lureau@redhat.com>
Cc: qemu-devel@nongnu.org
---
 chardev/char.c | 3 +++
 qapi/char.json | 6 +++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/chardev/char.c b/chardev/char.c
index d38a0c76a51e..ec9a6c4d2499 100644
--- a/chardev/char.c
+++ b/chardev/char.c
@@ -933,6 +933,9 @@ QemuOptsList qemu_chardev_opts = {
         },{
             .name = "mux",
             .type = QEMU_OPT_BOOL,
+        },{
+            .name = "mux-be-id",
+            .type = QEMU_OPT_STRING,
         },{
             .name = "signal",
             .type = QEMU_OPT_BOOL,
diff --git a/qapi/char.json b/qapi/char.json
index e04535435034..fb0dedb24383 100644
--- a/qapi/char.json
+++ b/qapi/char.json
@@ -199,11 +199,15 @@
 # @logappend: true to append instead of truncate (default to false to
 #     truncate)
 #
+# @mux-be-id: id of the mux-be device for backend multiplexing
+#     (since: 9.2)
+#
 # Since: 2.6
 ##
 { 'struct': 'ChardevCommon',
   'data': { '*logfile': 'str',
-            '*logappend': 'bool' } }
+            '*logappend': 'bool',
+            '*mux-be-id': 'str' } }
 
 ##
 # @ChardevFile:
-- 
2.34.1