1 files changed, 56 insertions, 0 deletions

diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index 936d7eee62d0..2e47f9f06b96 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -44,6 +44,10 @@ struct virtio_vsock {
 	spinlock_t send_pkt_list_lock;
 	struct list_head send_pkt_list;
 
+	struct work_struct loopback_work;
+	spinlock_t loopback_list_lock; /* protects loopback_list */
+	struct list_head loopback_list;
+
 	atomic_t queued_replies;
 
 	/* The following fields are protected by rx_lock.  vqs[VSOCK_VQ_RX]
@@ -74,6 +78,42 @@ static u32 virtio_transport_get_local_cid(void)
 	return vsock->guest_cid;
 }
 
+static void virtio_transport_loopback_work(struct work_struct *work)
+{
+	struct virtio_vsock *vsock =
+		container_of(work, struct virtio_vsock, loopback_work);
+	LIST_HEAD(pkts);
+
+	spin_lock_bh(&vsock->loopback_list_lock);
+	list_splice_init(&vsock->loopback_list, &pkts);
+	spin_unlock_bh(&vsock->loopback_list_lock);
+
+	mutex_lock(&vsock->rx_lock);
+	while (!list_empty(&pkts)) {
+		struct virtio_vsock_pkt *pkt;
+
+		pkt = list_first_entry(&pkts, struct virtio_vsock_pkt, list);
+		list_del_init(&pkt->list);
+
+		virtio_transport_recv_pkt(pkt);
+	}
+	mutex_unlock(&vsock->rx_lock);
+}
+
+static int virtio_transport_send_pkt_loopback(struct virtio_vsock *vsock,
+					      struct virtio_vsock_pkt *pkt)
+{
+	int len = pkt->len;
+
+	spin_lock_bh(&vsock->loopback_list_lock);
+	list_add_tail(&pkt->list, &vsock->loopback_list);
+	spin_unlock_bh(&vsock->loopback_list_lock);
+
+	queue_work(virtio_vsock_workqueue, &vsock->loopback_work);
+
+	return len;
+}
+
 static void
 virtio_transport_send_pkt_work(struct work_struct *work)
 {
@@ -159,6 +199,9 @@ virtio_transport_send_pkt(struct virtio_vsock_pkt *pkt)
 		return -ENODEV;
 	}
 
+	if (le32_to_cpu(pkt->hdr.dst_cid) == vsock->guest_cid)
+		return virtio_transport_send_pkt_loopback(vsock, pkt);
+
 	if (pkt->reply)
 		atomic_inc(&vsock->queued_replies);
 
@@ -510,10 +553,13 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
 	mutex_init(&vsock->event_lock);
 	spin_lock_init(&vsock->send_pkt_list_lock);
 	INIT_LIST_HEAD(&vsock->send_pkt_list);
+	spin_lock_init(&vsock->loopback_list_lock);
+	INIT_LIST_HEAD(&vsock->loopback_list);
 	INIT_WORK(&vsock->rx_work, virtio_transport_rx_work);
 	INIT_WORK(&vsock->tx_work, virtio_transport_tx_work);
 	INIT_WORK(&vsock->event_work, virtio_transport_event_work);
 	INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work);
+	INIT_WORK(&vsock->loopback_work, virtio_transport_loopback_work);
 
 	mutex_lock(&vsock->rx_lock);
 	virtio_vsock_rx_fill(vsock);
@@ -539,6 +585,7 @@ static void virtio_vsock_remove(struct virtio_device *vdev)
 	struct virtio_vsock *vsock = vdev->priv;
 	struct virtio_vsock_pkt *pkt;
 
+	flush_work(&vsock->loopback_work);
 	flush_work(&vsock->rx_work);
 	flush_work(&vsock->tx_work);
 	flush_work(&vsock->event_work);
@@ -565,6 +612,15 @@ static void virtio_vsock_remove(struct virtio_device *vdev)
 	}
 	spin_unlock_bh(&vsock->send_pkt_list_lock);
 
+	spin_lock_bh(&vsock->loopback_list_lock);
+	while (!list_empty(&vsock->loopback_list)) {
+		pkt = list_first_entry(&vsock->loopback_list,
+				       struct virtio_vsock_pkt, list);
+		list_del(&pkt->list);
+		virtio_transport_free_pkt(pkt);
+	}
+	spin_unlock_bh(&vsock->loopback_list_lock);
+
 	mutex_lock(&the_virtio_vsock_mutex);
 	the_virtio_vsock = NULL;
 	vsock_core_exit();