net/virtio-user: do not stop stopped device again

Without this change, virtio-user still works, but it will show
annoying error messages like this on shutdown:

vhost_kernel_set_backend(): VHOST_NET_SET_BACKEND fails, Operation not permitted
vhost_kernel_ioctl(): VHOST_RESET_OWNER failed: Operation not permitted

Fixes: e3b434818bbb ("net/virtio-user: support kernel vhost")
Fixes: 12ecb2f63b12 ("net/virtio-user: support memory hotplug")
Cc: stable@dpdk.org
Reported-by: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

diff --git a/drivers/net/virtio/virtio_user/virtio_user_dev.c b/drivers/net/virtio/virtio_user/virtio_user_dev.c
index b4997ee..0e35630 100644 (file)
--- a/drivers/net/virtio/virtio_user/virtio_user_dev.c
+++ b/drivers/net/virtio/virtio_user/virtio_user_dev.c
@@ -184,6 +184,9 @@ int virtio_user_stop_device(struct virtio_user_dev *dev)
        uint32_t i;
 
        pthread_mutex_lock(&dev->mutex);
+       if (!dev->started)
+               goto out;
+
        for (i = 0; i < dev->max_queue_pairs; ++i)
                dev->ops->enable_qp(dev, i, 0);
 
@@ -193,6 +196,7 @@ int virtio_user_stop_device(struct virtio_user_dev *dev)
                return -1;
        }
        dev->started = false;
+out:
        pthread_mutex_unlock(&dev->mutex);
 
        return 0;