Re: [PATCH 04/12] iommufd: Pass parent hwpt and user_data to iommufd_hw_pagetable_alloc()

[Jason Gunthorpe]

On Fri, Mar 17, 2023 at 10:23:54AM +0000, Tian, Kevin wrote:
> > From: Liu, Yi L <yi.l.liu@xxxxxxxxx>
> > Sent: Thursday, March 9, 2023 4:09 PM
> > 
> > +	/* It must be either NESTED or UNMANAGED, depending on
> > parent_domain */
> > +	if ((parent_domain && hwpt->domain->type !=
> > IOMMU_DOMAIN_NESTED) ||
> > +	    (!parent_domain && hwpt->domain->type !=
> > IOMMU_DOMAIN_UNMANAGED))
> > +		goto out_abort;
> > +
> 
> WARN_ON()

Wouldn't that be userspace triggerable? It gets to pick the hwpt used.

Jason