diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 9035486..49185f0 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -1036,9 +1036,9 @@ static int map_range_to_domain(const struct dt_device_node *dev,
     if ( need_mapping )
     {
         res = map_mmio_regions(d,
-                               paddr_to_pfn(addr),
+                               _gfn(paddr_to_pfn(addr)),
                                DIV_ROUND_UP(len, PAGE_SIZE),
-                               paddr_to_pfn(addr));
+                               _mfn(paddr_to_pfn(addr)));
         if ( res < 0 )
         {
             printk(XENLOG_ERR "Unable to map 0x%"PRIx64
diff --git a/xen/arch/arm/gic-v2.c b/xen/arch/arm/gic-v2.c
index 4e2f4c7..3893ece 100644
--- a/xen/arch/arm/gic-v2.c
+++ b/xen/arch/arm/gic-v2.c
@@ -601,9 +601,9 @@ static int gicv2_map_hwdown_extra_mappings(struct domain *d)
                d->domain_id, v2m_data->addr, v2m_data->size,
                v2m_data->spi_start, v2m_data->nr_spis);
 
-        ret = map_mmio_regions(d, paddr_to_pfn(v2m_data->addr),
+        ret = map_mmio_regions(d, _gfn(paddr_to_pfn(v2m_data->addr)),
                             DIV_ROUND_UP(v2m_data->size, PAGE_SIZE),
-                            paddr_to_pfn(v2m_data->addr));
+                            _mfn(paddr_to_pfn(v2m_data->addr)));
         if ( ret )
         {
             printk(XENLOG_ERR "GICv2: Map v2m frame to d%d failed.\n",
diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index 0395a40..34563bb 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -1245,27 +1245,27 @@ int unmap_regions_rw_cache(struct domain *d,
 }
 
 int map_mmio_regions(struct domain *d,
-                     unsigned long start_gfn,
+                     gfn_t start_gfn,
                      unsigned long nr,
-                     unsigned long mfn)
+                     mfn_t mfn)
 {
     return apply_p2m_changes(d, INSERT,
-                             pfn_to_paddr(start_gfn),
-                             pfn_to_paddr(start_gfn + nr),
-                             pfn_to_paddr(mfn),
+                             pfn_to_paddr(gfn_x(start_gfn)),
+                             pfn_to_paddr(gfn_x(start_gfn) + nr),
+                             pfn_to_paddr(mfn_x(mfn)),
                              MATTR_DEV, 0, p2m_mmio_direct,
                              d->arch.p2m.default_access);
 }
 
 int unmap_mmio_regions(struct domain *d,
-                       unsigned long start_gfn,
+                       gfn_t start_gfn,
                        unsigned long nr,
-                       unsigned long mfn)
+                       mfn_t mfn)
 {
     return apply_p2m_changes(d, REMOVE,
-                             pfn_to_paddr(start_gfn),
-                             pfn_to_paddr(start_gfn + nr),
-                             pfn_to_paddr(mfn),
+                             pfn_to_paddr(gfn_x(start_gfn)),
+                             pfn_to_paddr(gfn_x(start_gfn) + nr),
+                             pfn_to_paddr(mfn_x(mfn)),
                              MATTR_DEV, 0, p2m_invalid,
                              d->arch.p2m.default_access);
 }
@@ -1280,7 +1280,7 @@ int map_dev_mmio_region(struct domain *d,
     if ( !(nr && iomem_access_permitted(d, mfn, mfn + nr - 1)) )
         return 0;
 
-    res = map_mmio_regions(d, start_gfn, nr, mfn);
+    res = map_mmio_regions(d, _gfn(start_gfn), nr, _mfn(mfn));
     if ( res < 0 )
     {
         printk(XENLOG_G_ERR "Unable to map [%#lx - %#lx] in Dom%d\n",
diff --git a/xen/arch/arm/platforms/exynos5.c b/xen/arch/arm/platforms/exynos5.c
index bf4964d..c43934f 100644
--- a/xen/arch/arm/platforms/exynos5.c
+++ b/xen/arch/arm/platforms/exynos5.c
@@ -83,12 +83,12 @@ static int exynos5_init_time(void)
 static int exynos5250_specific_mapping(struct domain *d)
 {
     /* Map the chip ID */
-    map_mmio_regions(d, paddr_to_pfn(EXYNOS5_PA_CHIPID), 1,
-                     paddr_to_pfn(EXYNOS5_PA_CHIPID));
+    map_mmio_regions(d, _gfn(paddr_to_pfn(EXYNOS5_PA_CHIPID)), 1,
+                     _mfn(paddr_to_pfn(EXYNOS5_PA_CHIPID)));
 
     /* Map the PWM region */
-    map_mmio_regions(d, paddr_to_pfn(EXYNOS5_PA_TIMER), 2,
-                     paddr_to_pfn(EXYNOS5_PA_TIMER));
+    map_mmio_regions(d, _gfn(paddr_to_pfn(EXYNOS5_PA_TIMER)), 2,
+                     _mfn(paddr_to_pfn(EXYNOS5_PA_TIMER)));
 
     return 0;
 }
diff --git a/xen/arch/arm/platforms/omap5.c b/xen/arch/arm/platforms/omap5.c
index a49ba62..539588e 100644
--- a/xen/arch/arm/platforms/omap5.c
+++ b/xen/arch/arm/platforms/omap5.c
@@ -102,20 +102,20 @@ static int omap5_init_time(void)
 static int omap5_specific_mapping(struct domain *d)
 {
     /* Map the PRM module */
-    map_mmio_regions(d, paddr_to_pfn(OMAP5_PRM_BASE), 2,
-                     paddr_to_pfn(OMAP5_PRM_BASE));
+    map_mmio_regions(d, _gfn(paddr_to_pfn(OMAP5_PRM_BASE)), 2,
+                     _mfn(paddr_to_pfn(OMAP5_PRM_BASE)));
 
     /* Map the PRM_MPU */
-    map_mmio_regions(d, paddr_to_pfn(OMAP5_PRCM_MPU_BASE), 1,
-                     paddr_to_pfn(OMAP5_PRCM_MPU_BASE));
+    map_mmio_regions(d, _gfn(paddr_to_pfn(OMAP5_PRCM_MPU_BASE)), 1,
+                     _mfn(paddr_to_pfn(OMAP5_PRCM_MPU_BASE)));
 
     /* Map the Wakeup Gen */
-    map_mmio_regions(d, paddr_to_pfn(OMAP5_WKUPGEN_BASE), 1,
-                     paddr_to_pfn(OMAP5_WKUPGEN_BASE));
+    map_mmio_regions(d, _gfn(paddr_to_pfn(OMAP5_WKUPGEN_BASE)), 1,
+                     _mfn(paddr_to_pfn(OMAP5_WKUPGEN_BASE)));
 
     /* Map the on-chip SRAM */
-    map_mmio_regions(d, paddr_to_pfn(OMAP5_SRAM_PA), 32,
-                     paddr_to_pfn(OMAP5_SRAM_PA));
+    map_mmio_regions(d, _gfn(paddr_to_pfn(OMAP5_SRAM_PA)), 32,
+                     _mfn(paddr_to_pfn(OMAP5_SRAM_PA)));
 
     return 0;
 }
diff --git a/xen/arch/arm/vgic-v2.c b/xen/arch/arm/vgic-v2.c
index 9adb4a9..cbe61cf 100644
--- a/xen/arch/arm/vgic-v2.c
+++ b/xen/arch/arm/vgic-v2.c
@@ -688,8 +688,8 @@ static int vgic_v2_domain_init(struct domain *d)
      * Map the gic virtual cpu interface in the gic cpu interface
      * region of the guest.
      */
-    ret = map_mmio_regions(d, paddr_to_pfn(cbase), csize / PAGE_SIZE,
-                           paddr_to_pfn(vbase));
+    ret = map_mmio_regions(d, _gfn(paddr_to_pfn(cbase)), csize / PAGE_SIZE,
+                           _mfn(paddr_to_pfn(vbase)));
     if ( ret )
         return ret;
 
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 16733a4..6258a5b 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -2214,9 +2214,9 @@ static unsigned int mmio_order(const struct domain *d,
 #define MAP_MMIO_MAX_ITER 64 /* pretty arbitrary */
 
 int map_mmio_regions(struct domain *d,
-                     unsigned long start_gfn,
+                     gfn_t start_gfn,
                      unsigned long nr,
-                     unsigned long mfn)
+                     mfn_t mfn)
 {
     int ret = 0;
     unsigned long i;
@@ -2229,10 +2229,11 @@ int map_mmio_regions(struct domain *d,
           i += 1UL << order, ++iter )
     {
         /* OR'ing gfn and mfn values will return an order suitable to both. */
-        for ( order = mmio_order(d, (start_gfn + i) | (mfn + i), nr - i); ;
+        for ( order = mmio_order(d, (gfn_x(start_gfn) + i) | (mfn_x(mfn) + i), nr - i); ;
               order = ret - 1 )
         {
-            ret = set_mmio_p2m_entry(d, start_gfn + i, _mfn(mfn + i), order,
+            ret = set_mmio_p2m_entry(d, gfn_x(start_gfn) + i,
+                                     mfn_add(mfn, i), order,
                                      p2m_get_hostp2m(d)->default_access);
             if ( ret <= 0 )
                 break;
@@ -2246,9 +2247,9 @@ int map_mmio_regions(struct domain *d,
 }
 
 int unmap_mmio_regions(struct domain *d,
-                       unsigned long start_gfn,
+                       gfn_t start_gfn,
                        unsigned long nr,
-                       unsigned long mfn)
+                       mfn_t mfn)
 {
     int ret = 0;
     unsigned long i;
@@ -2261,10 +2262,11 @@ int unmap_mmio_regions(struct domain *d,
           i += 1UL << order, ++iter )
     {
         /* OR'ing gfn and mfn values will return an order suitable to both. */
-        for ( order = mmio_order(d, (start_gfn + i) | (mfn + i), nr - i); ;
+        for ( order = mmio_order(d, (gfn_x(start_gfn) + i) | (mfn_x(mfn) + i), nr - i); ;
               order = ret - 1 )
         {
-            ret = clear_mmio_p2m_entry(d, start_gfn + i, _mfn(mfn + i), order);
+            ret = clear_mmio_p2m_entry(d, gfn_x(start_gfn) + i,
+                                       mfn_add(mfn, i), order);
             if ( ret <= 0 )
                 break;
             ASSERT(ret <= order);
diff --git a/xen/common/domctl.c b/xen/common/domctl.c
index e43904e..b784e6c 100644
--- a/xen/common/domctl.c
+++ b/xen/common/domctl.c
@@ -1074,7 +1074,7 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl)
                    "memory_map:add: dom%d gfn=%lx mfn=%lx nr=%lx\n",
                    d->domain_id, gfn, mfn, nr_mfns);
 
-            ret = map_mmio_regions(d, gfn, nr_mfns, mfn);
+            ret = map_mmio_regions(d, _gfn(gfn), nr_mfns, _mfn(mfn));
             if ( ret < 0 )
                 printk(XENLOG_G_WARNING
                        "memory_map:fail: dom%d gfn=%lx mfn=%lx nr=%lx ret:%ld\n",
@@ -1086,7 +1086,7 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) u_domctl)
                    "memory_map:remove: dom%d gfn=%lx mfn=%lx nr=%lx\n",
                    d->domain_id, gfn, mfn, nr_mfns);
 
-            ret = unmap_mmio_regions(d, gfn, nr_mfns, mfn);
+            ret = unmap_mmio_regions(d, _gfn(gfn), nr_mfns, _mfn(mfn));
             if ( ret < 0 && is_hardware_domain(current->domain) )
                 printk(XENLOG_ERR
                        "memory_map: error %ld removing dom%d access to [%lx,%lx]\n",
diff --git a/xen/include/xen/p2m-common.h b/xen/include/xen/p2m-common.h
index 6374a5b..b4f9077 100644
--- a/xen/include/xen/p2m-common.h
+++ b/xen/include/xen/p2m-common.h
@@ -37,13 +37,13 @@ typedef enum {
  *  * the guest physical address space to map, starting from the machine
  *   * frame number mfn. */
 int map_mmio_regions(struct domain *d,
-                     unsigned long start_gfn,
+                     gfn_t start_gfn,
                      unsigned long nr,
-                     unsigned long mfn);
+                     mfn_t mfn);
 int unmap_mmio_regions(struct domain *d,
-                       unsigned long start_gfn,
+                       gfn_t start_gfn,
                        unsigned long nr,
-                       unsigned long mfn);
+                       mfn_t mfn);
 
 /*
  * Set access type for a region of gfns.
