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

[Jason Gunthorpe]

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);
        tmp_paddr = *paddr;
        /*
         * Scan the domain for the contiguous physical address length so that

Jason