[PATCH net-next 2/2] vsock/virtio: add support for device suspend/resume

Stefano Garzarella
2022-04-28T13:23:03Z

Implement .freeze and .restore callbacks of struct virtio_driver
to support device suspend/resume.

During suspension all connected sockets are reset and VQs deleted.
During resume the VQs are re-initialized.

Reported by: Vilas R K <vilas.r.k@intel.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
---
net/vmw_vsock/virtio_transport.c | 47 ++++++++++++++++++++++++++++++++
1 file changed, 47 insertions(+)

diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index 31f4f6f40614..ad64f403536a 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -743,6 +743,49 @@ static void virtio_vsock_remove(struct virtio_device *vdev)
kfree(vsock);
}

+#ifdef CONFIG_PM_SLEEP
+static int virtio_vsock_freeze(struct virtio_device *vdev)
+{
+ struct virtio_vsock *vsock = vdev->priv;
+
+ mutex_lock(&the_virtio_vsock_mutex);
+
+ rcu_assign_pointer(the_virtio_vsock, NULL);
+ synchronize_rcu();
+
+ virtio_vsock_vqs_del(vsock);
+
+ mutex_unlock(&the_virtio_vsock_mutex);
+
+ return 0;
+}
+
+static int virtio_vsock_restore(struct virtio_device *vdev)
+{
+ struct virtio_vsock *vsock = vdev->priv;
+ int ret;
+
+ mutex_lock(&the_virtio_vsock_mutex);
+
+ /* 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;
+ }
+
+ ret = virtio_vsock_vqs_init(vsock);
+ if (ret < 0)
+ goto out;
+
+ rcu_assign_pointer(the_virtio_vsock, vsock);
+
+out:
+ mutex_unlock(&the_virtio_vsock_mutex);
+ return ret;
+}
+#endif /* CONFIG_PM_SLEEP */
+
static struct virtio_device_id id_table[] = {
{ VIRTIO_ID_VSOCK, VIRTIO_DEV_ANY_ID },
{ 0 },
@@ -760,6 +803,10 @@ static struct virtio_driver virtio_vsock_driver = {
.id_table = id_table,
.probe = virtio_vsock_probe,
.remove = virtio_vsock_remove,
+#ifdef CONFIG_PM_SLEEP
+ .freeze = virtio_vsock_freeze,
+ .restore = virtio_vsock_restore,
+#endif
};

static int __init virtio_vsock_init(void)
--
2.35.1