1 files changed, 41 insertions, 0 deletions
diff --git a/blockdev.c b/blockdev.c
index e865ae4873..f75c01f664 100644
--- a/blockdev.c
+++ b/blockdev.c
@@ -45,6 +45,7 @@
 #include "qapi/qmp/qerror.h"
 #include "qapi/qobject-output-visitor.h"
 #include "sysemu/sysemu.h"
+#include "sysemu/iothread.h"
 #include "block/block_int.h"
 #include "qmp-commands.h"
 #include "block/trace.h"
@@ -4129,6 +4130,46 @@ BlockJobInfoList *qmp_query_block_jobs(Error **errp)
     return head;
 }
 
+void qmp_x_blockdev_set_iothread(const char *node_name, StrOrNull *iothread,
+                                 Error **errp)
+{
+    AioContext *old_context;
+    AioContext *new_context;
+    BlockDriverState *bs;
+
+    bs = bdrv_find_node(node_name);
+    if (!bs) {
+        error_setg(errp, "Cannot find node %s", node_name);
+        return;
+    }
+
+    /* If we want to allow more extreme test scenarios this guard could be
+     * removed.  For now it protects against accidents. */
+    if (bdrv_has_blk(bs)) {
+        error_setg(errp, "Node %s is in use", node_name);
+        return;
+    }
+
+    if (iothread->type == QTYPE_QSTRING) {
+        IOThread *obj = iothread_by_id(iothread->u.s);
+        if (!obj) {
+            error_setg(errp, "Cannot find iothread %s", iothread->u.s);
+            return;
+        }
+
+        new_context = iothread_get_aio_context(obj);
+    } else {
+        new_context = qemu_get_aio_context();
+    }
+
+    old_context = bdrv_get_aio_context(bs);
+    aio_context_acquire(old_context);
+
+    bdrv_set_aio_context(bs, new_context);
+
+    aio_context_release(old_context);
+}
+
 QemuOptsList qemu_common_drive_opts = {
     .name = "drive",
     .head = QTAILQ_HEAD_INITIALIZER(qemu_common_drive_opts.head),