[PATCH net-next 1/2] vsock/virtio: factor our the code to initialize and delete VQs

From: Stefano Garzarella
Date: Thu Apr 28 2022 - 09:22:56 EST


Add virtio_vsock_vqs_init() and virtio_vsock_vqs_del() with the code
that was in virtio_vsock_probe() and virtio_vsock_remove to initialize
and delete VQs.

These new functions will be used in the next commit to support device
suspend/resume

Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
---
net/vmw_vsock/virtio_transport.c | 150 +++++++++++++++++--------------
1 file changed, 84 insertions(+), 66 deletions(-)

diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index ba1c8cc0c467..31f4f6f40614 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -566,67 +566,28 @@ static void virtio_transport_rx_work(struct work_struct *work)
mutex_unlock(&vsock->rx_lock);
}

-static int virtio_vsock_probe(struct virtio_device *vdev)
+static int virtio_vsock_vqs_init(struct virtio_vsock *vsock)
{
- vq_callback_t *callbacks[] = {
- virtio_vsock_rx_done,
- virtio_vsock_tx_done,
- virtio_vsock_event_done,
- };
+ struct virtio_device *vdev = vsock->vdev;
static const char * const names[] = {
"rx",
"tx",
"event",
};
- struct virtio_vsock *vsock = NULL;
+ vq_callback_t *callbacks[] = {
+ virtio_vsock_rx_done,
+ virtio_vsock_tx_done,
+ virtio_vsock_event_done,
+ };
int ret;

- ret = mutex_lock_interruptible(&the_virtio_vsock_mutex);
- if (ret)
- return ret;
-
- /* Only one virtio-vsock device per guest is supported */
- if (rcu_dereference_protected(the_virtio_vsock,
- lockdep_is_held(&the_virtio_vsock_mutex))) {
- ret = -EBUSY;
- goto out;
- }
-
- vsock = kzalloc(sizeof(*vsock), GFP_KERNEL);
- if (!vsock) {
- ret = -ENOMEM;
- goto out;
- }
-
- vsock->vdev = vdev;
-
- ret = virtio_find_vqs(vsock->vdev, VSOCK_VQ_MAX,
- vsock->vqs, callbacks, names,
+ ret = virtio_find_vqs(vdev, VSOCK_VQ_MAX, vsock->vqs, callbacks, names,
NULL);
if (ret < 0)
- goto out;
+ return ret;

virtio_vsock_update_guest_cid(vsock);

- vsock->rx_buf_nr = 0;
- vsock->rx_buf_max_nr = 0;
- atomic_set(&vsock->queued_replies, 0);
-
- mutex_init(&vsock->tx_lock);
- mutex_init(&vsock->rx_lock);
- mutex_init(&vsock->event_lock);
- spin_lock_init(&vsock->send_pkt_list_lock);
- INIT_LIST_HEAD(&vsock->send_pkt_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);
-
- if (virtio_has_feature(vdev, VIRTIO_VSOCK_F_SEQPACKET))
- vsock->seqpacket_allow = true;
-
- vdev->priv = vsock;
-
virtio_device_ready(vdev);

mutex_lock(&vsock->tx_lock);
@@ -643,30 +604,15 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
vsock->event_run = true;
mutex_unlock(&vsock->event_lock);

- rcu_assign_pointer(the_virtio_vsock, vsock);
-
- mutex_unlock(&the_virtio_vsock_mutex);
-
return 0;
-
-out:
- kfree(vsock);
- mutex_unlock(&the_virtio_vsock_mutex);
- return ret;
}

-static void virtio_vsock_remove(struct virtio_device *vdev)
+static void virtio_vsock_vqs_del(struct virtio_vsock *vsock)
{
- struct virtio_vsock *vsock = vdev->priv;
+ struct virtio_device *vdev = vsock->vdev;
struct virtio_vsock_pkt *pkt;

- mutex_lock(&the_virtio_vsock_mutex);
-
- vdev->priv = NULL;
- rcu_assign_pointer(the_virtio_vsock, NULL);
- synchronize_rcu();
-
- /* Reset all connected sockets when the device disappear */
+ /* Reset all connected sockets when the VQs disappear */
vsock_for_each_connected_socket(&virtio_transport.transport,
virtio_vsock_reset_sock);

@@ -711,6 +657,78 @@ static void virtio_vsock_remove(struct virtio_device *vdev)

/* Delete virtqueues and flush outstanding callbacks if any */
vdev->config->del_vqs(vdev);
+}
+
+static int virtio_vsock_probe(struct virtio_device *vdev)
+{
+ struct virtio_vsock *vsock = NULL;
+ int ret;
+
+ ret = mutex_lock_interruptible(&the_virtio_vsock_mutex);
+ if (ret)
+ return ret;
+
+ /* Only one virtio-vsock device per guest is supported */
+ if (rcu_dereference_protected(the_virtio_vsock,
+ lockdep_is_held(&the_virtio_vsock_mutex))) {
+ ret = -EBUSY;
+ goto out;
+ }
+
+ vsock = kzalloc(sizeof(*vsock), GFP_KERNEL);
+ if (!vsock) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ vsock->vdev = vdev;
+
+ vsock->rx_buf_nr = 0;
+ vsock->rx_buf_max_nr = 0;
+ atomic_set(&vsock->queued_replies, 0);
+
+ mutex_init(&vsock->tx_lock);
+ mutex_init(&vsock->rx_lock);
+ mutex_init(&vsock->event_lock);
+ spin_lock_init(&vsock->send_pkt_list_lock);
+ INIT_LIST_HEAD(&vsock->send_pkt_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);
+
+ if (virtio_has_feature(vdev, VIRTIO_VSOCK_F_SEQPACKET))
+ vsock->seqpacket_allow = true;
+
+ vdev->priv = vsock;
+
+ ret = virtio_vsock_vqs_init(vsock);
+ if (ret < 0)
+ goto out;
+
+ rcu_assign_pointer(the_virtio_vsock, vsock);
+
+ mutex_unlock(&the_virtio_vsock_mutex);
+
+ return 0;
+
+out:
+ kfree(vsock);
+ mutex_unlock(&the_virtio_vsock_mutex);
+ return ret;
+}
+
+static void virtio_vsock_remove(struct virtio_device *vdev)
+{
+ struct virtio_vsock *vsock = vdev->priv;
+
+ mutex_lock(&the_virtio_vsock_mutex);
+
+ vdev->priv = NULL;
+ rcu_assign_pointer(the_virtio_vsock, NULL);
+ synchronize_rcu();
+
+ virtio_vsock_vqs_del(vsock);

/* Other works can be queued before 'config->del_vqs()', so we flush
* all works before to free the vsock object to avoid use after free.
--
2.35.1