On Wed, Mar 08, 2023 at 05:13:36AM -0800, Yi Liu wrote:
> +int iommufd_access_set_ioas(struct iommufd_access *access, u32 ioas_id)
> +{
> + struct iommufd_ioas *new_ioas = NULL, *cur_ioas;
> + struct iommufd_ctx *ictx = access->ictx;
> + struct iommufd_object *obj;
> + int rc = 0;
> +
> + if (ioas_id) {
> + obj = iommufd_get_object(ictx, ioas_id, IOMMUFD_OBJ_IOAS);
> + if (IS_ERR(obj))
> + return PTR_ERR(obj);
> + new_ioas = container_of(obj, struct iommufd_ioas, obj);
> + }
> +
> + mutex_lock(&access->ioas_lock);
> + cur_ioas = access->ioas;
> + if (cur_ioas == new_ioas)
> + goto out_unlock;
> +
> + if (new_ioas) {
> + rc = iopt_add_access(&new_ioas->iopt, access);
> + if (rc)
> + goto out_unlock;
> + iommufd_ref_to_users(obj);
> + }
> +
> + if (cur_ioas) {
> + iopt_remove_access(&cur_ioas->iopt, access);
> + refcount_dec(&cur_ioas->obj.users);
> + }
This should match the physical side with an add/remove/replace
API. Especially since remove is implicit in destroy this series only
needs the add API
And the locking shouldn't come in another patch that brings the
replace/remove since with just split add we don't need it.
That will make this patch alot smaller
Jason
