diff --git a/hw/i386/amd_iommu.c b/hw/i386/amd_iommu.c
index 12742b1433f82ffc2c482518eaa8671829dff851..77aee33b01d7bd8244ff7ef9d7cce37876466e0c 100644
--- a/hw/i386/amd_iommu.c
+++ b/hw/i386/amd_iommu.c
@@ -1543,9 +1543,9 @@ static void amdvi_pci_realize(PCIDevice *pdev, Error **errp)
     /* reset AMDVI specific capabilities, all r/o */
     pci_set_long(pdev->config + s->capab_offset, AMDVI_CAPAB_FEATURES);
     pci_set_long(pdev->config + s->capab_offset + AMDVI_CAPAB_BAR_LOW,
-                 AMDVI_BASE_ADDR & ~(0xffff0000));
+                 AMDVI_BASE_ADDR & MAKE_64BIT_MASK(14, 18));
     pci_set_long(pdev->config + s->capab_offset + AMDVI_CAPAB_BAR_HIGH,
-                (AMDVI_BASE_ADDR & ~(0xffff)) >> 16);
+                 AMDVI_BASE_ADDR >> 32);
     pci_set_long(pdev->config + s->capab_offset + AMDVI_CAPAB_RANGE,
                  0xff000000);
     pci_set_long(pdev->config + s->capab_offset + AMDVI_CAPAB_MISC, 0);
diff --git a/hw/i386/amd_iommu.h b/hw/i386/amd_iommu.h
index c5065a3e277299d14989941b6385d7d48a3e028d..555a7a51625da431d89c398e2db4c32d38b2848a 100644
--- a/hw/i386/amd_iommu.h
+++ b/hw/i386/amd_iommu.h
@@ -185,7 +185,7 @@
         AMDVI_CAPAB_FLAG_HTTUNNEL |  AMDVI_CAPAB_EFR_SUP)
 
 /* AMDVI default address */
-#define AMDVI_BASE_ADDR 0xfed80000
+#define AMDVI_BASE_ADDR 0xfed80000ULL
 
 /* page management constants */
 #define AMDVI_PAGE_SHIFT 12