vfio/type1: Use iommu_paging_domain_alloc()

Replace iommu_domain_alloc() with iommu_paging_domain_alloc().
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20240610085555.88197-4-baolu.lu@linux.intel.comSigned-off-by: Will Deacon <will@kernel.org>

drivers/vfio/vfio_iommu_type1.c

@@ -2135,7 +2135,7 @@ static int vfio_iommu_domain_alloc(struct device *dev, void *data)
 {
 	struct iommu_domain **domain = data;
 
-	*domain = iommu_domain_alloc(dev->bus);
+	*domain = iommu_paging_domain_alloc(dev);
 	return 1; /* Don't iterate */
 }
 
@@ -2192,11 +2192,12 @@ static int vfio_iommu_type1_attach_group(void *iommu_data,
 	 * us a representative device for the IOMMU API call. We don't actually
 	 * want to iterate beyond the first device (if any).
 	 */
-	ret = -EIO;
 	iommu_group_for_each_dev(iommu_group, &domain->domain,
 				 vfio_iommu_domain_alloc);
-	if (!domain->domain)
+	if (IS_ERR(domain->domain)) {
+		ret = PTR_ERR(domain->domain);
 		goto out_free_domain;
+	}
 
 	if (iommu->nesting) {
 		ret = iommu_enable_nesting(domain->domain);