Function destroy_device

dpdk/examples/vhost/main.c:1575–1638

* Remove a device from the specific data core linked list and from the * main linked list. Synchronization occurs through the use of the * lcore dev_removal_flag. Device is made volatile here to avoid re-ordering * of dev->remove=1 which can cause an infinite loop in the rte_pause loop. */

 * of dev->remove=1 which can cause an infinite loop in the rte_pause loop.
 */
static void
destroy_device(int vid)
{
	struct vhost_dev *vdev = NULL;
	int lcore;
	uint16_t i;

	TAILQ_FOREACH(vdev, &vhost_dev_list, global_vdev_entry) {
		if (vdev->vid == vid)
			break;
	}
	if (!vdev)
		return;
	/*set the remove flag. */
	vdev->remove = 1;
	while(vdev->ready != DEVICE_SAFE_REMOVE) {
		rte_pause();
	}

	for (i = 0; i < RTE_MAX_LCORE; i++)
		rte_free(vhost_txbuff[i * RTE_MAX_VHOST_DEVICE + vid]);

	if (builtin_net_driver)
		vs_vhost_net_remove(vdev);

	TAILQ_REMOVE(&lcore_info[vdev->coreid].vdev_list, vdev,
		     lcore_vdev_entry);
	TAILQ_REMOVE(&vhost_dev_list, vdev, global_vdev_entry);


	/* Set the dev_removal_flag on each lcore. */
	RTE_LCORE_FOREACH_WORKER(lcore)
		lcore_info[lcore].dev_removal_flag = REQUEST_DEV_REMOVAL;

	/*
	 * Once each core has set the dev_removal_flag to ACK_DEV_REMOVAL
	 * we can be sure that they can no longer access the device removed
	 * from the linked lists and that the devices are no longer in use.
	 */
	RTE_LCORE_FOREACH_WORKER(lcore) {
		while (lcore_info[lcore].dev_removal_flag != ACK_DEV_REMOVAL)
			rte_pause();
	}

	lcore_info[vdev->coreid].device_num--;

	RTE_LOG(INFO, VHOST_DATA,
		"(%d) device has been removed from data core\n",
		vdev->vid);

	if (dma_bind[vid].dmas[VIRTIO_RXQ].async_enabled) {
		vhost_clear_queue(vdev, VIRTIO_RXQ);
		rte_vhost_async_channel_unregister(vid, VIRTIO_RXQ);
		dma_bind[vid].dmas[VIRTIO_RXQ].async_enabled = false;
	}

	if (dma_bind[vid].dmas[VIRTIO_TXQ].async_enabled) {
		vhost_clear_queue(vdev, VIRTIO_TXQ);