RE: [PATCH v2 22/31] iommu/vt-d: Export a helper to do function for each dmar_drhd_unit

[Tian, Kevin]

> From: Xu Yilun <yilun.xu@xxxxxxxxxxxxxxx>
> Sent: Saturday, March 28, 2026 12:01 AM
> 
> @@ -86,6 +86,8 @@ extern struct list_head dmar_drhd_units;
>  				dmar_rcu_check())			\
>  		if (i=drhd->iommu, 0) {} else
> 
> +int do_for_each_drhd_unit(int (*fn)(struct dmar_drhd_unit *));
> +
>  static inline bool dmar_rcu_check(void)

It's a bit weird to insert it here. Move it to follow for_each_iommu().

> +
> +int do_for_each_drhd_unit(int (*fn)(struct dmar_drhd_unit *))
> +{
> +	struct dmar_drhd_unit *drhd;
> +	int ret;
> +
> +	guard(rwsem_read)(&dmar_global_lock);
> +
> +	for_each_drhd_unit(drhd) {
> +		ret = fn(drhd);
> +		if (ret)
> +			return ret;
> +	}
> +	return 0;
> +}

use for_each_active_drhd_unit(). or is there need to setup the trusted
configuration even on ignored iommu?