1 files changed, 134 insertions, 30 deletions

diff --git a/chardev/char.c b/chardev/char.c
index 2b679a2295..c34b44abc9 100644
--- a/chardev/char.c
+++ b/chardev/char.c
@@ -556,17 +556,23 @@ help_string_append(const char *name, void *opaque)
     g_string_append_printf(str, "\n%s", name);
 }
 
-Chardev *qemu_chr_new_from_opts(QemuOpts *opts,
-                                Error **errp)
+static const char *chardev_alias_translate(const char *name)
+{
+    int i;
+    for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
+        if (g_strcmp0(chardev_alias_table[i].alias, name) == 0) {
+            return chardev_alias_table[i].typename;
+        }
+    }
+    return name;
+}
+
+ChardevBackend *qemu_chr_parse_opts(QemuOpts *opts, Error **errp)
 {
     Error *local_err = NULL;
     const ChardevClass *cc;
-    Chardev *chr;
-    int i;
     ChardevBackend *backend = NULL;
-    const char *name = qemu_opt_get(opts, "backend");
-    const char *id = qemu_opts_id(opts);
-    char *bid = NULL;
+    const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
 
     if (name == NULL) {
         error_setg(errp, "chardev: \"%s\" missing backend",
@@ -574,7 +580,40 @@ Chardev *qemu_chr_new_from_opts(QemuOpts *opts,
         return NULL;
     }
 
-    if (is_help_option(name)) {
+    cc = char_get_class(name, errp);
+    if (cc == NULL) {
+        return NULL;
+    }
+
+    backend = g_new0(ChardevBackend, 1);
+    backend->type = CHARDEV_BACKEND_KIND_NULL;
+
+    if (cc->parse) {
+        cc->parse(opts, backend, &local_err);
+        if (local_err) {
+            error_propagate(errp, local_err);
+            qapi_free_ChardevBackend(backend);
+            return NULL;
+        }
+    } else {
+        ChardevCommon *ccom = g_new0(ChardevCommon, 1);
+        qemu_chr_parse_common(opts, ccom);
+        backend->u.null.data = ccom; /* Any ChardevCommon member would work */
+    }
+
+    return backend;
+}
+
+Chardev *qemu_chr_new_from_opts(QemuOpts *opts, Error **errp)
+{
+    const ChardevClass *cc;
+    Chardev *chr = NULL;
+    ChardevBackend *backend = NULL;
+    const char *name = chardev_alias_translate(qemu_opt_get(opts, "backend"));
+    const char *id = qemu_opts_id(opts);
+    char *bid = NULL;
+
+    if (name && is_help_option(name)) {
         GString *str = g_string_new("");
 
         chardev_name_foreach(help_string_append, str);
@@ -589,38 +628,20 @@ Chardev *qemu_chr_new_from_opts(QemuOpts *opts,
         return NULL;
     }
 
-    for (i = 0; i < (int)ARRAY_SIZE(chardev_alias_table); i++) {
-        if (g_strcmp0(chardev_alias_table[i].alias, name) == 0) {
-            name = chardev_alias_table[i].typename;
-            break;
-        }
+    backend = qemu_chr_parse_opts(opts, errp);
+    if (backend == NULL) {
+        return NULL;
     }
 
     cc = char_get_class(name, errp);
     if (cc == NULL) {
-        return NULL;
+        goto out;
     }
 
-    backend = g_new0(ChardevBackend, 1);
-    backend->type = CHARDEV_BACKEND_KIND_NULL;
-
     if (qemu_opt_get_bool(opts, "mux", 0)) {
         bid = g_strdup_printf("%s-base", id);
     }
 
-    chr = NULL;
-    if (cc->parse) {
-        cc->parse(opts, backend, &local_err);
-        if (local_err) {
-            error_propagate(errp, local_err);
-            goto out;
-        }
-    } else {
-        ChardevCommon *ccom = g_new0(ChardevCommon, 1);
-        qemu_chr_parse_common(opts, ccom);
-        backend->u.null.data = ccom; /* Any ChardevCommon member would work */
-    }
-
     chr = qemu_chardev_new(bid ? bid : id,
                            object_class_get_name(OBJECT_CLASS(cc)),
                            backend, errp);
@@ -930,6 +951,89 @@ ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
     return ret;
 }
 
+ChardevReturn *qmp_chardev_change(const char *id, ChardevBackend *backend,
+                                  Error **errp)
+{
+    CharBackend *be;
+    const ChardevClass *cc;
+    Chardev *chr, *chr_new;
+    bool closed_sent = false;
+    ChardevReturn *ret;
+
+    chr = qemu_chr_find(id);
+    if (!chr) {
+        error_setg(errp, "Chardev '%s' does not exist", id);
+        return NULL;
+    }
+
+    if (CHARDEV_IS_MUX(chr)) {
+        error_setg(errp, "Mux device hotswap not supported yet");
+        return NULL;
+    }
+
+    if (qemu_chr_replay(chr)) {
+        error_setg(errp,
+            "Chardev '%s' cannot be changed in record/replay mode", id);
+        return NULL;
+    }
+
+    be = chr->be;
+    if (!be) {
+        /* easy case */
+        object_unparent(OBJECT(chr));
+        return qmp_chardev_add(id, backend, errp);
+    }
+
+    if (!be->chr_be_change) {
+        error_setg(errp, "Chardev user does not support chardev hotswap");
+        return NULL;
+    }
+
+    cc = char_get_class(ChardevBackendKind_lookup[backend->type], errp);
+    if (!cc) {
+        return NULL;
+    }
+
+    chr_new = qemu_chardev_new(NULL, object_class_get_name(OBJECT_CLASS(cc)),
+                               backend, errp);
+    if (!chr_new) {
+        return NULL;
+    }
+    chr_new->label = g_strdup(id);
+
+    if (chr->be_open && !chr_new->be_open) {
+        qemu_chr_be_event(chr, CHR_EVENT_CLOSED);
+        closed_sent = true;
+    }
+
+    chr->be = NULL;
+    qemu_chr_fe_init(be, chr_new, &error_abort);
+
+    if (be->chr_be_change(be->opaque) < 0) {
+        error_setg(errp, "Chardev '%s' change failed", chr_new->label);
+        chr_new->be = NULL;
+        qemu_chr_fe_init(be, chr, &error_abort);
+        if (closed_sent) {
+            qemu_chr_be_event(chr, CHR_EVENT_OPENED);
+        }
+        object_unref(OBJECT(chr_new));
+        return NULL;
+    }
+
+    object_unparent(OBJECT(chr));
+    object_property_add_child(get_chardevs_root(), chr_new->label,
+                              OBJECT(chr_new), &error_abort);
+    object_unref(OBJECT(chr_new));
+
+    ret = g_new0(ChardevReturn, 1);
+    if (CHARDEV_IS_PTY(chr_new)) {
+        ret->pty = g_strdup(chr_new->filename + 4);
+        ret->has_pty = true;
+    }
+
+    return ret;
+}
+
 void qmp_chardev_remove(const char *id, Error **errp)
 {
     Chardev *chr;