diff --git a/xen/drivers/passthrough/amd/iommu_map.c b/xen/drivers/passthrough/amd/iommu_map.c
index daa24a4858..e0f4fe736a 100644
--- a/xen/drivers/passthrough/amd/iommu_map.c
+++ b/xen/drivers/passthrough/amd/iommu_map.c
@@ -837,9 +837,7 @@ static int fill_qpt(union amd_iommu_pte *this, unsigned int level,
 int cf_check amd_iommu_quarantine_init(struct pci_dev *pdev, bool scratch_page)
 {
     struct domain_iommu *hd = dom_iommu(dom_io);
-    unsigned long end_gfn =
-        1UL << (DEFAULT_DOMAIN_ADDRESS_WIDTH - PAGE_SHIFT);
-    unsigned int level = amd_iommu_get_paging_mode(end_gfn);
+    unsigned int level = hd->arch.amd.paging_mode;
     unsigned int req_id = get_dma_requestor_id(pdev->seg, pdev->sbdf.bdf);
     const struct ivrs_mappings *ivrs_mappings = get_ivrs_mappings(pdev->seg);
     int rc;