@@ -22,6 +22,7 @@
 #include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/kthread.h>
+#include <linux/cgroup.h>
 #include <linux/module.h>
 #include <linux/sort.h>
 #include <linux/sched/mm.h>

@@ -621,6 +622,57 @@ long vhost_dev_check_owner(struct vhost_dev *dev)
 }
 EXPORT_SYMBOL_GPL(vhost_dev_check_owner);
 
+struct vhost_attach_cgroups_struct {
+	struct vhost_work work;
+	struct task_struct *owner;
+	int ret;
+};
+
+static void vhost_attach_cgroups_work(struct vhost_work *work)
+{
+	struct vhost_attach_cgroups_struct *s;
+
+	s = container_of(work, struct vhost_attach_cgroups_struct, work);
+	s->ret = cgroup_attach_task_all(s->owner, current);
+}
+
+static int vhost_worker_cgroups_kthread(struct vhost_worker *worker)
+{
+	struct vhost_flush_struct flush;
+	struct vhost_attach_cgroups_struct attach;
+
+	attach.owner = current;
+
+	vhost_work_init(&attach.work, vhost_attach_cgroups_work);
+	vhost_worker_queue(worker, &attach.work);
+
+	init_completion(&flush.wait_event);
+	vhost_work_init(&flush.work, vhost_flush_work);
+	vhost_worker_queue(worker, &flush.work);
+	wait_for_completion(&flush.wait_event);
+
+	return attach.ret;
+}
+
+static int vhost_attach_cgroups(struct vhost_dev *dev)
+{
+	struct vhost_worker *worker;
+	unsigned long i;
+	int ret;
+
+	/*
+	 * Free the default worker we created and cleanup workers userspace
+	 * created but couldn't clean up (it forgot or crashed).
+	 */
+
+	xa_for_each(&dev->worker_xa, i, worker) {
+		ret = vhost_worker_cgroups_kthread(worker);
+		if (ret)
+			return ret;
+	}
+	return ret;
+}
+
 /* Caller should have device mutex */
 bool vhost_dev_has_owner(struct vhost_dev *dev)
 {