diff --git a/hw/arm/sysbus-fdt.c b/hw/arm/sysbus-fdt.c
index 04afeae..49bd212 100644
--- a/hw/arm/sysbus-fdt.c
+++ b/hw/arm/sysbus-fdt.c
@@ -240,7 +240,7 @@ static int add_calxeda_midway_xgmac_fdt_node(SysBusDevice *sbdev, void *opaque)
         mmio_base = platform_bus_get_mmio_addr(pbus, sbdev, i);
         reg_attr[2 * i] = cpu_to_be32(mmio_base);
         reg_attr[2 * i + 1] = cpu_to_be32(
-                                memory_region_size(&vdev->regions[i]->mem));
+                                memory_region_size(vdev->regions[i]->mem));
     }
     qemu_fdt_setprop(fdt, nodename, "reg", reg_attr,
                      vbasedev->num_regions * 2 * sizeof(uint32_t));
@@ -374,7 +374,7 @@ static int add_amd_xgbe_fdt_node(SysBusDevice *sbdev, void *opaque)
         mmio_base = platform_bus_get_mmio_addr(pbus, sbdev, i);
         reg_attr[2 * i] = cpu_to_be32(mmio_base);
         reg_attr[2 * i + 1] = cpu_to_be32(
-                                memory_region_size(&vdev->regions[i]->mem));
+                                memory_region_size(vdev->regions[i]->mem));
     }
     qemu_fdt_setprop(guest_fdt, nodename, "reg", reg_attr,
                      vbasedev->num_regions * 2 * sizeof(uint32_t));
diff --git a/hw/vfio/common.c b/hw/vfio/common.c
index e20fc4f..96ccb79 100644
--- a/hw/vfio/common.c
+++ b/hw/vfio/common.c
@@ -493,46 +493,162 @@ static void vfio_listener_release(VFIOContainer *container)
     memory_listener_unregister(&container->listener);
 }
 
-int vfio_mmap_region(Object *obj, VFIORegion *region,
-                     MemoryRegion *mem, MemoryRegion *submem,
-                     void **map, size_t size, off_t offset,
-                     const char *name)
+int vfio_region_setup(Object *obj, VFIODevice *vbasedev, VFIORegion *region,
+                      int index, const char *name)
 {
-    int ret = 0;
-    VFIODevice *vbasedev = region->vbasedev;
+    struct vfio_region_info *info;
+    int ret;
+
+    ret = vfio_get_region_info(vbasedev, index, &info);
+    if (ret) {
+        return ret;
+    }
+
+    region->vbasedev = vbasedev;
+    region->flags = info->flags;
+    region->size = info->size;
+    region->fd_offset = info->offset;
+    region->nr = index;
 
-    if (!vbasedev->no_mmap && size && region->flags &
-        VFIO_REGION_INFO_FLAG_MMAP) {
-        int prot = 0;
+    if (region->size) {
+        region->mem = g_new0(MemoryRegion, 1);
+        memory_region_init_io(region->mem, obj, &vfio_region_ops,
+                              region, name, region->size);
 
-        if (region->flags & VFIO_REGION_INFO_FLAG_READ) {
-            prot |= PROT_READ;
+        if (!vbasedev->no_mmap &&
+            region->flags & VFIO_REGION_INFO_FLAG_MMAP &&
+            !(region->size & ~qemu_real_host_page_mask)) {
+
+            region->nr_mmaps = 1;
+            region->mmaps = g_new0(VFIOMmap, region->nr_mmaps);
+
+            region->mmaps[0].offset = 0;
+            region->mmaps[0].size = region->size;
         }
+    }
+
+    g_free(info);
+
+    trace_vfio_region_setup(vbasedev->name, index, name,
+                            region->flags, region->fd_offset, region->size);
+    return 0;
+}
 
-        if (region->flags & VFIO_REGION_INFO_FLAG_WRITE) {
-            prot |= PROT_WRITE;
+int vfio_region_mmap(VFIORegion *region)
+{
+    int i, prot = 0;
+    char *name;
+
+    if (!region->mem) {
+        return 0;
+    }
+
+    prot |= region->flags & VFIO_REGION_INFO_FLAG_READ ? PROT_READ : 0;
+    prot |= region->flags & VFIO_REGION_INFO_FLAG_WRITE ? PROT_WRITE : 0;
+
+    for (i = 0; i < region->nr_mmaps; i++) {
+        region->mmaps[i].mmap = mmap(NULL, region->mmaps[i].size, prot,
+                                     MAP_SHARED, region->vbasedev->fd,
+                                     region->fd_offset +
+                                     region->mmaps[i].offset);
+        if (region->mmaps[i].mmap == MAP_FAILED) {
+            int ret = -errno;
+
+            trace_vfio_region_mmap_fault(memory_region_name(region->mem), i,
+                                         region->fd_offset +
+                                         region->mmaps[i].offset,
+                                         region->fd_offset +
+                                         region->mmaps[i].offset +
+                                         region->mmaps[i].size - 1, ret);
+
+            region->mmaps[i].mmap = NULL;
+
+            for (i--; i >= 0; i--) {
+                memory_region_del_subregion(region->mem, &region->mmaps[i].mem);
+                munmap(region->mmaps[i].mmap, region->mmaps[i].size);
+                object_unparent(OBJECT(&region->mmaps[i].mem));
+                region->mmaps[i].mmap = NULL;
+            }
+
+            return ret;
         }
 
-        *map = mmap(NULL, size, prot, MAP_SHARED,
-                    vbasedev->fd,
-                    region->fd_offset + offset);
-        if (*map == MAP_FAILED) {
-            *map = NULL;
-            ret = -errno;
-            goto empty_region;
+        name = g_strdup_printf("%s mmaps[%d]",
+                               memory_region_name(region->mem), i);
+        memory_region_init_ram_ptr(&region->mmaps[i].mem,
+                                   memory_region_owner(region->mem),
+                                   name, region->mmaps[i].size,
+                                   region->mmaps[i].mmap);
+        g_free(name);
+        memory_region_set_skip_dump(&region->mmaps[i].mem);
+        memory_region_add_subregion(region->mem, region->mmaps[i].offset,
+                                    &region->mmaps[i].mem);
+
+        trace_vfio_region_mmap(memory_region_name(&region->mmaps[i].mem),
+                               region->mmaps[i].offset,
+                               region->mmaps[i].offset +
+                               region->mmaps[i].size - 1);
+    }
+
+    return 0;
+}
+
+void vfio_region_exit(VFIORegion *region)
+{
+    int i;
+
+    if (!region->mem) {
+        return;
+    }
+
+    for (i = 0; i < region->nr_mmaps; i++) {
+        if (region->mmaps[i].mmap) {
+            memory_region_del_subregion(region->mem, &region->mmaps[i].mem);
         }
+    }
 
-        memory_region_init_ram_ptr(submem, obj, name, size, *map);
-        memory_region_set_skip_dump(submem);
-    } else {
-empty_region:
-        /* Create a zero sized sub-region to make cleanup easy. */
-        memory_region_init(submem, obj, name, 0);
+    trace_vfio_region_exit(region->vbasedev->name, region->nr);
+}
+
+void vfio_region_finalize(VFIORegion *region)
+{
+    int i;
+
+    if (!region->mem) {
+        return;
     }
 
-    memory_region_add_subregion(mem, offset, submem);
+    for (i = 0; i < region->nr_mmaps; i++) {
+        if (region->mmaps[i].mmap) {
+            munmap(region->mmaps[i].mmap, region->mmaps[i].size);
+            object_unparent(OBJECT(&region->mmaps[i].mem));
+        }
+    }
 
-    return ret;
+    object_unparent(OBJECT(region->mem));
+
+    g_free(region->mem);
+    g_free(region->mmaps);
+
+    trace_vfio_region_finalize(region->vbasedev->name, region->nr);
+}
+
+void vfio_region_mmaps_set_enabled(VFIORegion *region, bool enabled)
+{
+    int i;
+
+    if (!region->mem) {
+        return;
+    }
+
+    for (i = 0; i < region->nr_mmaps; i++) {
+        if (region->mmaps[i].mmap) {
+            memory_region_set_enabled(&region->mmaps[i].mem, enabled);
+        }
+    }
+
+    trace_vfio_region_mmaps_set_enabled(memory_region_name(region->mem),
+                                        enabled);
 }
 
 void vfio_reset_handler(void *opaque)
diff --git a/hw/vfio/pci-quirks.c b/hw/vfio/pci-quirks.c
index 4815527..d626ec9 100644
--- a/hw/vfio/pci-quirks.c
+++ b/hw/vfio/pci-quirks.c
@@ -337,14 +337,14 @@ static void vfio_probe_ati_bar4_quirk(VFIOPCIDevice *vdev, int nr)
     memory_region_init_io(window->addr_mem, OBJECT(vdev),
                           &vfio_generic_window_address_quirk, window,
                           "vfio-ati-bar4-window-address-quirk", 4);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         window->address_offset,
                                         window->addr_mem, 1);
 
     memory_region_init_io(window->data_mem, OBJECT(vdev),
                           &vfio_generic_window_data_quirk, window,
                           "vfio-ati-bar4-window-data-quirk", 4);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         window->data_offset,
                                         window->data_mem, 1);
 
@@ -378,7 +378,7 @@ static void vfio_probe_ati_bar2_quirk(VFIOPCIDevice *vdev, int nr)
     memory_region_init_io(mirror->mem, OBJECT(vdev),
                           &vfio_generic_mirror_quirk, mirror,
                           "vfio-ati-bar2-4000-quirk", PCI_CONFIG_SPACE_SIZE);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         mirror->offset, mirror->mem, 1);
 
     QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, quirk, next);
@@ -683,7 +683,7 @@ static void vfio_probe_nvidia_bar5_quirk(VFIOPCIDevice *vdev, int nr)
     memory_region_init_io(window->addr_mem, OBJECT(vdev),
                           &vfio_generic_window_address_quirk, window,
                           "vfio-nvidia-bar5-window-address-quirk", 4);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         window->address_offset,
                                         window->addr_mem, 1);
     memory_region_set_enabled(window->addr_mem, false);
@@ -691,7 +691,7 @@ static void vfio_probe_nvidia_bar5_quirk(VFIOPCIDevice *vdev, int nr)
     memory_region_init_io(window->data_mem, OBJECT(vdev),
                           &vfio_generic_window_data_quirk, window,
                           "vfio-nvidia-bar5-window-data-quirk", 4);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         window->data_offset,
                                         window->data_mem, 1);
     memory_region_set_enabled(window->data_mem, false);
@@ -699,13 +699,13 @@ static void vfio_probe_nvidia_bar5_quirk(VFIOPCIDevice *vdev, int nr)
     memory_region_init_io(&quirk->mem[2], OBJECT(vdev),
                           &vfio_nvidia_bar5_quirk_master, bar5,
                           "vfio-nvidia-bar5-master-quirk", 4);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         0, &quirk->mem[2], 1);
 
     memory_region_init_io(&quirk->mem[3], OBJECT(vdev),
                           &vfio_nvidia_bar5_quirk_enable, bar5,
                           "vfio-nvidia-bar5-enable-quirk", 4);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         4, &quirk->mem[3], 1);
 
     QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, quirk, next);
@@ -767,7 +767,7 @@ static void vfio_probe_nvidia_bar0_quirk(VFIOPCIDevice *vdev, int nr)
                           &vfio_nvidia_mirror_quirk, mirror,
                           "vfio-nvidia-bar0-88000-mirror-quirk",
                           vdev->config_size);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         mirror->offset, mirror->mem, 1);
 
     QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, quirk, next);
@@ -786,7 +786,7 @@ static void vfio_probe_nvidia_bar0_quirk(VFIOPCIDevice *vdev, int nr)
                               &vfio_nvidia_mirror_quirk, mirror,
                               "vfio-nvidia-bar0-1800-mirror-quirk",
                               PCI_CONFIG_SPACE_SIZE);
-        memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+        memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                             mirror->offset, mirror->mem, 1);
 
         QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, quirk, next);
@@ -947,13 +947,13 @@ static void vfio_probe_rtl8168_bar2_quirk(VFIOPCIDevice *vdev, int nr)
     memory_region_init_io(&quirk->mem[0], OBJECT(vdev),
                           &vfio_rtl_address_quirk, rtl,
                           "vfio-rtl8168-window-address-quirk", 4);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         0x74, &quirk->mem[0], 1);
 
     memory_region_init_io(&quirk->mem[1], OBJECT(vdev),
                           &vfio_rtl_data_quirk, rtl,
                           "vfio-rtl8168-window-data-quirk", 4);
-    memory_region_add_subregion_overlap(&vdev->bars[nr].region.mem,
+    memory_region_add_subregion_overlap(vdev->bars[nr].region.mem,
                                         0x70, &quirk->mem[1], 1);
 
     QLIST_INSERT_HEAD(&vdev->bars[nr].quirks, quirk, next);
@@ -1020,7 +1020,7 @@ void vfio_bar_quirk_teardown(VFIOPCIDevice *vdev, int nr)
 
     QLIST_FOREACH(quirk, &bar->quirks, next) {
         for (i = 0; i < quirk->nr_mem; i++) {
-            memory_region_del_subregion(&bar->region.mem, &quirk->mem[i]);
+            memory_region_del_subregion(bar->region.mem, &quirk->mem[i]);
         }
     }
 }
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index db7a950..f18a678 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -1166,6 +1166,74 @@ static int vfio_msi_setup(VFIOPCIDevice *vdev, int pos)
     return 0;
 }
 
+static void vfio_pci_fixup_msix_region(VFIOPCIDevice *vdev)
+{
+    off_t start, end;
+    VFIORegion *region = &vdev->bars[vdev->msix->table_bar].region;
+
+    /*
+     * We expect to find a single mmap covering the whole BAR, anything else
+     * means it's either unsupported or already setup.
+     */
+    if (region->nr_mmaps != 1 || region->mmaps[0].offset ||
+        region->size != region->mmaps[0].size) {
+        return;
+    }
+
+    /* MSI-X table start and end aligned to host page size */
+    start = vdev->msix->table_offset & qemu_real_host_page_mask;
+    end = REAL_HOST_PAGE_ALIGN((uint64_t)vdev->msix->table_offset +
+                               (vdev->msix->entries * PCI_MSIX_ENTRY_SIZE));
+
+    /*
+     * Does the MSI-X table cover the beginning of the BAR?  The whole BAR?
+     * NB - Host page size is necessarily a power of two and so is the PCI
+     * BAR (not counting EA yet), therefore if we have host page aligned
+     * @start and @end, then any remainder of the BAR before or after those
+     * must be at least host page sized and therefore mmap'able.
+     */
+    if (!start) {
+        if (end >= region->size) {
+            region->nr_mmaps = 0;
+            g_free(region->mmaps);
+            region->mmaps = NULL;
+            trace_vfio_msix_fixup(vdev->vbasedev.name,
+                                  vdev->msix->table_bar, 0, 0);
+        } else {
+            region->mmaps[0].offset = end;
+            region->mmaps[0].size = region->size - end;
+            trace_vfio_msix_fixup(vdev->vbasedev.name,
+                              vdev->msix->table_bar, region->mmaps[0].offset,
+                              region->mmaps[0].offset + region->mmaps[0].size);
+        }
+
+    /* Maybe it's aligned at the end of the BAR */
+    } else if (end >= region->size) {
+        region->mmaps[0].size = start;
+        trace_vfio_msix_fixup(vdev->vbasedev.name,
+                              vdev->msix->table_bar, region->mmaps[0].offset,
+                              region->mmaps[0].offset + region->mmaps[0].size);
+
+    /* Otherwise it must split the BAR */
+    } else {
+        region->nr_mmaps = 2;
+        region->mmaps = g_renew(VFIOMmap, region->mmaps, 2);
+
+        memcpy(&region->mmaps[1], &region->mmaps[0], sizeof(VFIOMmap));
+
+        region->mmaps[0].size = start;
+        trace_vfio_msix_fixup(vdev->vbasedev.name,
+                              vdev->msix->table_bar, region->mmaps[0].offset,
+                              region->mmaps[0].offset + region->mmaps[0].size);
+
+        region->mmaps[1].offset = end;
+        region->mmaps[1].size = region->size - end;
+        trace_vfio_msix_fixup(vdev->vbasedev.name,
+                              vdev->msix->table_bar, region->mmaps[1].offset,
+                              region->mmaps[1].offset + region->mmaps[1].size);
+    }
+}
+
 /*
  * We don't have any control over how pci_add_capability() inserts
  * capabilities into the chain.  In order to setup MSI-X we need a
@@ -1240,6 +1308,8 @@ static int vfio_msix_early_setup(VFIOPCIDevice *vdev)
                                 msix->table_offset, msix->entries);
     vdev->msix = msix;
 
+    vfio_pci_fixup_msix_region(vdev);
+
     return 0;
 }
 
@@ -1250,9 +1320,9 @@ static int vfio_msix_setup(VFIOPCIDevice *vdev, int pos)
     vdev->msix->pending = g_malloc0(BITS_TO_LONGS(vdev->msix->entries) *
                                     sizeof(unsigned long));
     ret = msix_init(&vdev->pdev, vdev->msix->entries,
-                    &vdev->bars[vdev->msix->table_bar].region.mem,
+                    vdev->bars[vdev->msix->table_bar].region.mem,
                     vdev->msix->table_bar, vdev->msix->table_offset,
-                    &vdev->bars[vdev->msix->pba_bar].region.mem,
+                    vdev->bars[vdev->msix->pba_bar].region.mem,
                     vdev->msix->pba_bar, vdev->msix->pba_offset, pos);
     if (ret < 0) {
         if (ret == -ENOTSUP) {
@@ -1289,8 +1359,8 @@ static void vfio_teardown_msi(VFIOPCIDevice *vdev)
 
     if (vdev->msix) {
         msix_uninit(&vdev->pdev,
-                    &vdev->bars[vdev->msix->table_bar].region.mem,
-                    &vdev->bars[vdev->msix->pba_bar].region.mem);
+                    vdev->bars[vdev->msix->table_bar].region.mem,
+                    vdev->bars[vdev->msix->pba_bar].region.mem);
         g_free(vdev->msix->pending);
     }
 }
@@ -1303,16 +1373,7 @@ static void vfio_mmap_set_enabled(VFIOPCIDevice *vdev, bool enabled)
     int i;
 
     for (i = 0; i < PCI_ROM_SLOT; i++) {
-        VFIOBAR *bar = &vdev->bars[i];
-
-        if (!bar->region.size) {
-            continue;
-        }
-
-        memory_region_set_enabled(&bar->region.mmap_mem, enabled);
-        if (vdev->msix && vdev->msix->table_bar == i) {
-            memory_region_set_enabled(&vdev->msix->mmap_mem, enabled);
-        }
+        vfio_region_mmaps_set_enabled(&vdev->bars[i].region, enabled);
     }
 }
 
@@ -1326,11 +1387,7 @@ static void vfio_unregister_bar(VFIOPCIDevice *vdev, int nr)
 
     vfio_bar_quirk_teardown(vdev, nr);
 
-    memory_region_del_subregion(&bar->region.mem, &bar->region.mmap_mem);
-
-    if (vdev->msix && vdev->msix->table_bar == nr) {
-        memory_region_del_subregion(&bar->region.mem, &vdev->msix->mmap_mem);
-    }
+    vfio_region_exit(&bar->region);
 }
 
 static void vfio_unmap_bar(VFIOPCIDevice *vdev, int nr)
@@ -1343,18 +1400,13 @@ static void vfio_unmap_bar(VFIOPCIDevice *vdev, int nr)
 
     vfio_bar_quirk_free(vdev, nr);
 
-    munmap(bar->region.mmap, memory_region_size(&bar->region.mmap_mem));
-
-    if (vdev->msix && vdev->msix->table_bar == nr) {
-        munmap(vdev->msix->mmap, memory_region_size(&vdev->msix->mmap_mem));
-    }
+    vfio_region_finalize(&bar->region);
 }
 
 static void vfio_map_bar(VFIOPCIDevice *vdev, int nr)
 {
     VFIOBAR *bar = &vdev->bars[nr];
     uint64_t size = bar->region.size;
-    char name[64];
     uint32_t pci_bar;
     uint8_t type;
     int ret;
@@ -1364,8 +1416,6 @@ static void vfio_map_bar(VFIOPCIDevice *vdev, int nr)
         return;
     }
 
-    snprintf(name, sizeof(name), "VFIO %s BAR %d", vdev->vbasedev.name, nr);
-
     /* Determine what type of BAR this is for registration */
     ret = pread(vdev->vbasedev.fd, &pci_bar, sizeof(pci_bar),
                 vdev->config_offset + PCI_BASE_ADDRESS_0 + (4 * nr));
@@ -1380,41 +1430,11 @@ static void vfio_map_bar(VFIOPCIDevice *vdev, int nr)
     type = pci_bar & (bar->ioport ? ~PCI_BASE_ADDRESS_IO_MASK :
                                     ~PCI_BASE_ADDRESS_MEM_MASK);
 
-    /* A "slow" read/write mapping underlies all BARs */
-    memory_region_init_io(&bar->region.mem, OBJECT(vdev), &vfio_region_ops,
-                          bar, name, size);
-    pci_register_bar(&vdev->pdev, nr, type, &bar->region.mem);
-
-    /*
-     * We can't mmap areas overlapping the MSIX vector table, so we
-     * potentially insert a direct-mapped subregion before and after it.
-     */
-    if (vdev->msix && vdev->msix->table_bar == nr) {
-        size = vdev->msix->table_offset & qemu_real_host_page_mask;
-    }
-
-    strncat(name, " mmap", sizeof(name) - strlen(name) - 1);
-    if (vfio_mmap_region(OBJECT(vdev), &bar->region, &bar->region.mem,
-                      &bar->region.mmap_mem, &bar->region.mmap,
-                      size, 0, name)) {
-        error_report("%s unsupported. Performance may be slow", name);
-    }
-
-    if (vdev->msix && vdev->msix->table_bar == nr) {
-        uint64_t start;
-
-        start = REAL_HOST_PAGE_ALIGN((uint64_t)vdev->msix->table_offset +
-                                     (vdev->msix->entries *
-                                      PCI_MSIX_ENTRY_SIZE));
+    pci_register_bar(&vdev->pdev, nr, type, bar->region.mem);
 
-        size = start < bar->region.size ? bar->region.size - start : 0;
-        strncat(name, " msix-hi", sizeof(name) - strlen(name) - 1);
-        /* VFIOMSIXInfo contains another MemoryRegion for this mapping */
-        if (vfio_mmap_region(OBJECT(vdev), &bar->region, &bar->region.mem,
-                          &vdev->msix->mmap_mem,
-                          &vdev->msix->mmap, size, start, name)) {
-            error_report("%s unsupported. Performance may be slow", name);
-        }
+    if (vfio_region_mmap(&bar->region)) {
+        error_report("Failed to mmap %s BAR %d. Performance may be slow",
+                     vdev->vbasedev.name, nr);
     }
 
     vfio_bar_quirk_setup(vdev, nr);
@@ -2049,25 +2069,18 @@ static int vfio_populate_device(VFIOPCIDevice *vdev)
     }
 
     for (i = VFIO_PCI_BAR0_REGION_INDEX; i < VFIO_PCI_ROM_REGION_INDEX; i++) {
-        ret = vfio_get_region_info(vbasedev, i, &reg_info);
+        char *name = g_strdup_printf("%s BAR %d", vbasedev->name, i);
+
+        ret = vfio_region_setup(OBJECT(vdev), vbasedev,
+                                &vdev->bars[i].region, i, name);
+        g_free(name);
+
         if (ret) {
             error_report("vfio: Error getting region %d info: %m", i);
             goto error;
         }
 
-        trace_vfio_populate_device_region(vbasedev->name, i,
-                                          (unsigned long)reg_info->size,
-                                          (unsigned long)reg_info->offset,
-                                          (unsigned long)reg_info->flags);
-
-        vdev->bars[i].region.vbasedev = vbasedev;
-        vdev->bars[i].region.flags = reg_info->flags;
-        vdev->bars[i].region.size = reg_info->size;
-        vdev->bars[i].region.fd_offset = reg_info->offset;
-        vdev->bars[i].region.nr = i;
         QLIST_INIT(&vdev->bars[i].quirks);
-
-        g_free(reg_info);
     }
 
     ret = vfio_get_region_info(vbasedev,
@@ -2153,11 +2166,8 @@ error:
 static void vfio_put_device(VFIOPCIDevice *vdev)
 {
     g_free(vdev->vbasedev.name);
-    if (vdev->msix) {
-        object_unparent(OBJECT(&vdev->msix->mmap_mem));
-        g_free(vdev->msix);
-        vdev->msix = NULL;
-    }
+    g_free(vdev->msix);
+
     vfio_put_base_device(&vdev->vbasedev);
 }
 
diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
index f9b9c20..a2ab75d 100644
--- a/hw/vfio/platform.c
+++ b/hw/vfio/platform.c
@@ -143,12 +143,8 @@ static void vfio_mmap_set_enabled(VFIOPlatformDevice *vdev, bool enabled)
 {
     int i;
 
-    trace_vfio_platform_mmap_set_enabled(enabled);
-
     for (i = 0; i < vdev->vbasedev.num_regions; i++) {
-        VFIORegion *region = vdev->regions[i];
-
-        memory_region_set_enabled(&region->mmap_mem, enabled);
+        vfio_region_mmaps_set_enabled(vdev->regions[i], enabled);
     }
 }
 
@@ -476,29 +472,16 @@ static int vfio_populate_device(VFIODevice *vbasedev)
     vdev->regions = g_new0(VFIORegion *, vbasedev->num_regions);
 
     for (i = 0; i < vbasedev->num_regions; i++) {
-        struct vfio_region_info *reg_info;
-        VFIORegion *ptr;
+        char *name = g_strdup_printf("VFIO %s region %d\n", vbasedev->name, i);
 
         vdev->regions[i] = g_new0(VFIORegion, 1);
-        ptr = vdev->regions[i];
-        ret = vfio_get_region_info(vbasedev, i, &reg_info);
+        ret = vfio_region_setup(OBJECT(vdev), vbasedev,
+                                vdev->regions[i], i, name);
+        g_free(name);
         if (ret) {
             error_report("vfio: Error getting region %d info: %m", i);
             goto reg_error;
         }
-        ptr->flags = reg_info->flags;
-        ptr->size = reg_info->size;
-        ptr->fd_offset = reg_info->offset;
-        ptr->nr = i;
-        ptr->vbasedev = vbasedev;
-
-        g_free(reg_info);
-
-        trace_vfio_platform_populate_regions(ptr->nr,
-                            (unsigned long)ptr->flags,
-                            (unsigned long)ptr->size,
-                            ptr->vbasedev->fd,
-                            (unsigned long)ptr->fd_offset);
     }
 
     vdev->mmap_timer = timer_new_ms(QEMU_CLOCK_VIRTUAL,
@@ -535,6 +518,9 @@ irq_err:
     }
 reg_error:
     for (i = 0; i < vbasedev->num_regions; i++) {
+        if (vdev->regions[i]) {
+            vfio_region_finalize(vdev->regions[i]);
+        }
         g_free(vdev->regions[i]);
     }
     g_free(vdev->regions);
@@ -636,41 +622,6 @@ static int vfio_base_device_init(VFIODevice *vbasedev)
 }
 
 /**
- * vfio_map_region - initialize the 2 memory regions for a given
- * MMIO region index
- * @vdev: the VFIO platform device handle
- * @nr: the index of the region
- *
- * Init the top memory region and the mmapped memory region beneath
- * VFIOPlatformDevice is used since VFIODevice is not a QOM Object
- * and could not be passed to memory region functions
-*/
-static void vfio_map_region(VFIOPlatformDevice *vdev, int nr)
-{
-    VFIORegion *region = vdev->regions[nr];
-    uint64_t size = region->size;
-    char name[64];
-
-    if (!size) {
-        return;
-    }
-
-    g_snprintf(name, sizeof(name), "VFIO %s region %d",
-               vdev->vbasedev.name, nr);
-
-    /* A "slow" read/write mapping underlies all regions */
-    memory_region_init_io(&region->mem, OBJECT(vdev), &vfio_region_ops,
-                          region, name, size);
-
-    g_strlcat(name, " mmap", sizeof(name));
-
-    if (vfio_mmap_region(OBJECT(vdev), region, &region->mem,
-                         &region->mmap_mem, &region->mmap, size, 0, name)) {
-        error_report("%s unsupported. Performance may be slow", name);
-    }
-}
-
-/**
  * vfio_platform_realize  - the device realize function
  * @dev: device state pointer
  * @errp: error
@@ -700,8 +651,11 @@ static void vfio_platform_realize(DeviceState *dev, Error **errp)
     }
 
     for (i = 0; i < vbasedev->num_regions; i++) {
-        vfio_map_region(vdev, i);
-        sysbus_init_mmio(sbdev, &vdev->regions[i]->mem);
+        if (vfio_region_mmap(vdev->regions[i])) {
+            error_report("%s mmap unsupported. Performance may be slow",
+                         memory_region_name(vdev->regions[i]->mem));
+        }
+        sysbus_init_mmio(sbdev, vdev->regions[i]->mem);
     }
 }
 
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index 371383c..594905a 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -41,14 +41,21 @@ enum {
     VFIO_DEVICE_TYPE_PLATFORM = 1,
 };
 
+typedef struct VFIOMmap {
+    MemoryRegion mem;
+    void *mmap;
+    off_t offset;
+    size_t size;
+} VFIOMmap;
+
 typedef struct VFIORegion {
     struct VFIODevice *vbasedev;
     off_t fd_offset; /* offset of region within device fd */
-    MemoryRegion mem; /* slow, read/write access */
-    MemoryRegion mmap_mem; /* direct mapped access */
-    void *mmap;
+    MemoryRegion *mem; /* slow, read/write access */
     size_t size;
     uint32_t flags; /* VFIO region flags (rd/wr/mmap) */
+    uint32_t nr_mmaps;
+    VFIOMmap *mmaps;
     uint8_t nr; /* cache the region number for debug */
 } VFIORegion;
 
@@ -126,10 +133,12 @@ void vfio_region_write(void *opaque, hwaddr addr,
                            uint64_t data, unsigned size);
 uint64_t vfio_region_read(void *opaque,
                           hwaddr addr, unsigned size);
-int vfio_mmap_region(Object *vdev, VFIORegion *region,
-                     MemoryRegion *mem, MemoryRegion *submem,
-                     void **map, size_t size, off_t offset,
-                     const char *name);
+int vfio_region_setup(Object *obj, VFIODevice *vbasedev, VFIORegion *region,
+                      int index, const char *name);
+int vfio_region_mmap(VFIORegion *region);
+void vfio_region_mmaps_set_enabled(VFIORegion *region, bool enabled);
+void vfio_region_exit(VFIORegion *region);
+void vfio_region_finalize(VFIORegion *region);
 void vfio_reset_handler(void *opaque);
 VFIOGroup *vfio_get_group(int groupid, AddressSpace *as);
 void vfio_put_group(VFIOGroup *group);
diff --git a/trace-events b/trace-events
index 6fba6cc..e36bc07 100644
--- a/trace-events
+++ b/trace-events
@@ -1652,6 +1652,7 @@ vfio_msix_enable(const char *name) " (%s)"
 vfio_msix_pba_disable(const char *name) " (%s)"
 vfio_msix_pba_enable(const char *name) " (%s)"
 vfio_msix_disable(const char *name) " (%s)"
+vfio_msix_fixup(const char *name, int bar, off_t offset, size_t size) " (%s) MSI-X region %d mmap fixup [0x%lx - 0x%lx]"
 vfio_msi_enable(const char *name, int nr_vectors) " (%s) Enabled %d MSI vectors"
 vfio_msi_disable(const char *name) " (%s)"
 vfio_pci_load_rom(const char *name, unsigned long size, unsigned long offset, unsigned long flags) "Device %s ROM:\n  size: 0x%lx, offset: 0x%lx, flags: 0x%lx"
@@ -1670,7 +1671,6 @@ vfio_pci_hot_reset(const char *name, const char *type) " (%s) %s"
 vfio_pci_hot_reset_has_dep_devices(const char *name) "%s: hot reset dependent devices:"
 vfio_pci_hot_reset_dep_devices(int domain, int bus, int slot, int function, int group_id) "\t%04x:%02x:%02x.%x group %d"
 vfio_pci_hot_reset_result(const char *name, const char *result) "%s hot reset: %s"
-vfio_populate_device_region(const char *region_name, int index, unsigned long size, unsigned long offset, unsigned long flags) "Device %s region %d:\n  size: 0x%lx, offset: 0x%lx, flags: 0x%lx"
 vfio_populate_device_config(const char *name, unsigned long size, unsigned long offset, unsigned long flags) "Device %s config:\n  size: 0x%lx, offset: 0x%lx, flags: 0x%lx"
 vfio_populate_device_get_irq_info_failure(void) "VFIO_DEVICE_GET_IRQ_INFO failure: %m"
 vfio_initfn(const char *name, int group_id) " (%s) group %d"
@@ -1726,13 +1726,17 @@ vfio_disconnect_container(int fd) "close container->fd=%d"
 vfio_put_group(int fd) "close group->fd=%d"
 vfio_get_device(const char * name, unsigned int flags, unsigned int num_regions, unsigned int num_irqs) "Device %s flags: %u, regions: %u, irqs: %u"
 vfio_put_base_device(int fd) "close vdev->fd=%d"
+vfio_region_setup(const char *dev, int index, const char *name, unsigned long flags, unsigned long offset, unsigned long size) "Device %s, region %d \"%s\", flags: %lx, offset: %lx, size: %lx"
+vfio_region_mmap_fault(const char *name, int index, unsigned long offset, unsigned long size, int fault) "Region %s mmaps[%d], [%lx - %lx], fault: %d"
+vfio_region_mmap(const char *name, unsigned long offset, unsigned long end) "Region %s [%lx - %lx]"
+vfio_region_exit(const char *name, int index) "Device %s, region %d"
+vfio_region_finalize(const char *name, int index) "Device %s, region %d"
+vfio_region_mmaps_set_enabled(const char *name, bool enabled) "Region %s mmaps enabled: %d"
 
 # hw/vfio/platform.c
-vfio_platform_populate_regions(int region_index, unsigned long flag, unsigned long size, int fd, unsigned long offset) "- region %d flags = 0x%lx, size = 0x%lx, fd= %d, offset = 0x%lx"
 vfio_platform_base_device_init(char *name, int groupid) "%s belongs to group #%d"
 vfio_platform_realize(char *name, char *compat) "vfio device %s, compat = %s"
 vfio_platform_eoi(int pin, int fd) "EOI IRQ pin %d (fd=%d)"
-vfio_platform_mmap_set_enabled(bool enabled) "fast path = %d"
 vfio_platform_intp_mmap_enable(int pin) "IRQ #%d still active, stay in slow path"
 vfio_platform_intp_interrupt(int pin, int fd) "Inject IRQ #%d (fd = %d)"
 vfio_platform_intp_inject_pending_lockheld(int pin, int fd) "Inject pending IRQ #%d (fd = %d)"
