blk_insert_bs() requires that callers hold the AioContext lock for the
node that should be inserted. Take it.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
---
 hw/core/qdev-properties-system.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/hw/core/qdev-properties-system.c b/hw/core/qdev-properties-system.c
index d42493f630..6d5d43eda2 100644
--- a/hw/core/qdev-properties-system.c
+++ b/hw/core/qdev-properties-system.c
@@ -143,11 +143,15 @@ static void set_drive_helper(Object *obj, Visitor *v, const char *name,
              * aware of iothreads require their BlockBackends to be in the main
              * AioContext.
              */
-            ctx = iothread ? bdrv_get_aio_context(bs) : qemu_get_aio_context();
-            blk = blk_new(ctx, 0, BLK_PERM_ALL);
+            ctx = bdrv_get_aio_context(bs);
+            blk = blk_new(iothread ? ctx : qemu_get_aio_context(),
+                          0, BLK_PERM_ALL);
             blk_created = true;
 
+            aio_context_acquire(ctx);
             ret = blk_insert_bs(blk, bs, errp);
+            aio_context_release(ctx);
+
             if (ret < 0) {
                 goto fail;
             }
-- 
2.40.1