chardev: generate an internal id when none given

Internally, qemu may create chardev without ID. Those will not be
looked up with qemu_chr_find(), which prevents using qdev_prop_set_chr().

Use id_generate(), to generate an internal name (prefixed with #), so
no conflict exist with user-named chardev.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: xiaoqiang zhao <zxq_yx_007@163.com>

chardev/char.c

@@ -37,6 +37,7 @@
 #include "qemu/help_option.h"
 #include "qemu/module.h"
 #include "qemu/option.h"
+#include "qemu/id.h"
 
 #include "chardev/char-mux.h"
 
@@ -944,10 +945,10 @@ void qemu_chr_set_feature(Chardev *chr,
     return set_bit(feature, chr->features);
 }
 
-Chardev *qemu_chardev_new(const char *id, const char *typename,
+static Chardev *chardev_new(const char *id, const char *typename,
-                          ChardevBackend *backend,
+                            ChardevBackend *backend,
-                          GMainContext *gcontext,
+                            GMainContext *gcontext,
-                          Error **errp)
+                            Error **errp)
 {
     Object *obj;
     Chardev *chr = NULL;
@@ -991,6 +992,21 @@ end:
     return chr;
 }
 
+Chardev *qemu_chardev_new(const char *id, const char *typename,
+                          ChardevBackend *backend,
+                          GMainContext *gcontext,
+                          Error **errp)
+{
+    g_autofree char *genid = NULL;
+
+    if (!id) {
+        genid = id_generate(ID_CHR);
+        id = genid;
+    }
+
+    return chardev_new(id, typename, backend, gcontext, errp);
+}
+
 ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
                                Error **errp)
 {
@@ -1003,8 +1019,8 @@ ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
         return NULL;
     }
 
-    chr = qemu_chardev_new(id, object_class_get_name(OBJECT_CLASS(cc)),
+    chr = chardev_new(id, object_class_get_name(OBJECT_CLASS(cc)),
-                           backend, NULL, errp);
+                      backend, NULL, errp);
     if (!chr) {
         return NULL;
     }
@@ -1061,8 +1077,8 @@ ChardevReturn *qmp_chardev_change(const char *id, ChardevBackend *backend,
         return NULL;
     }
 
-    chr_new = qemu_chardev_new(NULL, object_class_get_name(OBJECT_CLASS(cc)),
+    chr_new = chardev_new(NULL, object_class_get_name(OBJECT_CLASS(cc)),
-                               backend, chr->gcontext, errp);
+                          backend, chr->gcontext, errp);
     if (!chr_new) {
         return NULL;
     }

include/qemu/id.h

@@ -4,6 +4,7 @@
 typedef enum IdSubSystems {
     ID_QDEV,
     ID_BLOCK,
+    ID_CHR,
     ID_MAX      /* last element, used as array size */
 } IdSubSystems;
 

util/id.c

@@ -34,6 +34,7 @@ bool id_wellformed(const char *id)
 static const char *const id_subsys_str[ID_MAX] = {
     [ID_QDEV]  = "qdev",
     [ID_BLOCK] = "block",
+    [ID_CHR] = "chr",
 };
 
 /*