Re: [PATCH V3 04/10] iommufd: Add an ioctl IOMMU_IOAS_GET_PA to query PA from IOVA

[Jacob Pan]

Hi Jason,

On Thu, 9 Apr 2026 15:26:24 -0300
Jason Gunthorpe <jgg@xxxxxxxxxx> wrote:

> On Thu, Apr 02, 2026 at 10:11:40PM -0700, Jacob Pan wrote:
> > +	*paddr = iommu_iova_to_phys(area->storage_domain, iova);
> > +	if (!*paddr) {
> > +		rc = -EINVAL;
> > +		goto unlock_exit;
> > +	}
> > +
> > +	tmp_length = PAGE_SIZE;
> > +	tmp_paddr = *paddr;  
> 
> shashiko also points out that the length is too long if IOVA is
> unaligned. We adjust the phys for unaligned IOVA but not the length:
> 
> @@ -879,7 +879,7 @@ int iopt_get_phys(struct io_pagetable *iopt,
> unsigned long iova, u64 *paddr, goto unlock_exit;
>         }
>  
> -       tmp_length = PAGE_SIZE;
> +       tmp_length = PAGE_SIZE - offset_in_page(iova);
Will fix and add an unaligned iova in selftest
vfio_iommufd_noiommu_test.

Thanks,

Jacob