Re: [PATCH] bus/vdev: add custom scan hook

[Thomas Monjalon <thomas@monjalon.net>]

06/12/2017 03:52, Tan, Jianfeng:
> On 12/1/2017 8:36 AM, Thomas Monjalon wrote:
> > +int
> > +rte_vdev_add_custom_scan(rte_vdev_scan_callback callback, void *user_arg)
> > +{
> > +	struct vdev_custom_scan *custom_scan;
> > +
> > +	rte_spinlock_lock(&vdev_custom_scan_lock);
> > +
> > +	/* check if already registered */
> > +	TAILQ_FOREACH(custom_scan, &vdev_custom_scans, next) {
> > +		if (custom_scan->callback == callback &&
> > +				custom_scan->user_arg == user_arg)
> > +			break;
> > +	}
> > +
> > +	if (custom_scan == NULL) {
> > +		custom_scan = malloc(sizeof(struct vdev_custom_scan));
> > +		if (custom_scan != NULL) {
> > +			custom_scan->callback = callback;
> > +			custom_scan->user_arg = user_arg;
> > +			TAILQ_INSERT_TAIL(&vdev_custom_scans, custom_scan, next);
> > +		}
> > +	}
> > +
> > +	rte_spinlock_unlock(&vdev_custom_scan_lock);
> > +
> > +	return (custom_scan == NULL) ? -ENOMEM : 0;
> > +}
> > +
> > +int
> > +rte_vdev_remove_custom_scan(rte_vdev_scan_callback callback, void *user_arg)
> > +{
> > +	struct vdev_custom_scan *custom_scan, *tmp_scan;
> > +
> > +	rte_spinlock_lock(&vdev_custom_scan_lock);
> > +	TAILQ_FOREACH_SAFE(custom_scan, &vdev_custom_scans, next, tmp_scan) {
> > +		if (custom_scan->callback != callback ||
> > +				(custom_scan->user_arg != (void *)-1 &&
> > +				custom_scan->user_arg != user_arg))
> > +			continue;
> > +		TAILQ_REMOVE(&vdev_custom_scans, custom_scan, next);
> > +		free(custom_scan);
> > +	}
> > +	rte_spinlock_unlock(&vdev_custom_scan_lock);
> > +
> > +	return 0;
> > +}
> > +
> >   static int
> >   vdev_parse(const char *name, void *addr)
> >   {
> > @@ -260,6 +319,22 @@ vdev_scan(void)
> >   {
> >   	struct rte_vdev_device *dev;
> >   	struct rte_devargs *devargs;
> > +	struct vdev_custom_scan *custom_scan;
> > +
> > +	/* call custom scan callbacks if any */
> > +	rte_spinlock_lock(&vdev_custom_scan_lock);
> > +	TAILQ_FOREACH(custom_scan, &vdev_custom_scans, next) {
> > +		if (custom_scan->callback != NULL)
> > +			/*
> > +			 * the callback should update devargs list
> > +			 * by calling rte_eal_devargs_insert() with
> > +			 *     devargs.bus = rte_bus_find_by_name("vdev");
> > +			 *     devargs.type = RTE_DEVTYPE_VIRTUAL;
> > +			 *     devargs.policy = RTE_DEV_WHITELISTED;
> > +			 */
> > +			custom_scan->callback(custom_scan->user_arg);
> > +	}
> > +	rte_spinlock_unlock(&vdev_custom_scan_lock);
> 
> You mentioned that we want to call the hook in the scan(), but it's now 
> in parse()?

No, it is in vdev_scan.
Look carefully the patch, especially after @@.