chardev: add qmp hotplug commands, with null chardev support

Add chardev-add and chardev-remove qmp commands.  Hotplugging
a null chardev is supported for now, more will be added later.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/qemu-char.c b/qemu-char.c
index ea15d357d0..73a5e37aa7 100644
--- a/qemu-char.c
+++ b/qemu-char.c
@@ -3010,3 +3010,56 @@ QemuOptsList qemu_chardev_opts = {
         { /* end of list */ }
     },
 };
+
+ChardevReturn *qmp_chardev_add(const char *id, ChardevBackend *backend,
+                               Error **errp)
+{
+    ChardevReturn *ret = g_new0(ChardevReturn, 1);
+    CharDriverState *chr = NULL;
+
+    chr = qemu_chr_find(id);
+    if (chr) {
+        error_setg(errp, "Chardev '%s' already exists", id);
+        g_free(ret);
+        return NULL;
+    }
+
+    switch (backend->kind) {
+    case CHARDEV_BACKEND_KIND_NULL:
+        chr = qemu_chr_open_null(NULL);
+        break;
+    default:
+        error_setg(errp, "unknown chardev backend (%d)", backend->kind);
+        break;
+    }
+
+    if (chr == NULL && !error_is_set(errp)) {
+        error_setg(errp, "Failed to create chardev");
+    }
+    if (chr) {
+        chr->label = g_strdup(id);
+        chr->avail_connections = 1;
+        QTAILQ_INSERT_TAIL(&chardevs, chr, next);
+        return ret;
+    } else {
+        g_free(ret);
+        return NULL;
+    }
+}
+
+void qmp_chardev_remove(const char *id, Error **errp)
+{
+    CharDriverState *chr;
+
+    chr = qemu_chr_find(id);
+    if (NULL == chr) {
+        error_setg(errp, "Chardev '%s' not found", id);
+        return;
+    }
+    if (chr->chr_can_read || chr->chr_read ||
+        chr->chr_event || chr->handler_opaque) {
+        error_setg(errp, "Chardev '%s' is busy", id);
+        return;
+    }
+    qemu_chr_delete(chr);
+}