diff --git a/MAINTAINERS b/MAINTAINERS
index dc0aa5424e..5c4e23eacb 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -866,6 +866,7 @@ VFIO
 M: Alex Williamson <alex.williamson@redhat.com>
 S: Supported
 F: hw/vfio/*
+F: include/hw/vfio/
 
 vhost
 M: Michael S. Tsirkin <mst@redhat.com>
diff --git a/hw/arm/sysbus-fdt.c b/hw/arm/sysbus-fdt.c
index 04afeae226..49bd212d07 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 607ec70be3..96ccb797fe 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;
 
-    if (!vbasedev->no_mmap && size && region->flags &
-        VFIO_REGION_INFO_FLAG_MMAP) {
-        int prot = 0;
-
-        if (region->flags & VFIO_REGION_INFO_FLAG_READ) {
-            prot |= PROT_READ;
-        }
-
-        if (region->flags & VFIO_REGION_INFO_FLAG_WRITE) {
-            prot |= PROT_WRITE;
-        }
-
-        *map = mmap(NULL, size, prot, MAP_SHARED,
-                    vbasedev->fd,
-                    region->fd_offset + offset);
-        if (*map == MAP_FAILED) {
-            *map = NULL;
-            ret = -errno;
-            goto empty_region;
-        }
-
-        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);
+    ret = vfio_get_region_info(vbasedev, index, &info);
+    if (ret) {
+        return ret;
     }
 
-    memory_region_add_subregion(mem, offset, submem);
+    region->vbasedev = vbasedev;
+    region->flags = info->flags;
+    region->size = info->size;
+    region->fd_offset = info->offset;
+    region->nr = index;
 
-    return ret;
+    if (region->size) {
+        region->mem = g_new0(MemoryRegion, 1);
+        memory_region_init_io(region->mem, obj, &vfio_region_ops,
+                              region, name, region->size);
+
+        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;
+}
+
+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;
+        }
+
+        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);
+        }
+    }
+
+    trace_vfio_region_exit(region->vbasedev->name, region->nr);
+}
+
+void vfio_region_finalize(VFIORegion *region)
+{
+    int i;
+
+    if (!region->mem) {
+        return;
+    }
+
+    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));
+        }
+    }
+
+    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)
@@ -959,6 +1075,24 @@ void vfio_put_base_device(VFIODevice *vbasedev)
     close(vbasedev->fd);
 }
 
+int vfio_get_region_info(VFIODevice *vbasedev, int index,
+                         struct vfio_region_info **info)
+{
+    size_t argsz = sizeof(struct vfio_region_info);
+
+    *info = g_malloc0(argsz);
+
+    (*info)->index = index;
+    (*info)->argsz = argsz;
+
+    if (ioctl(vbasedev->fd, VFIO_DEVICE_GET_REGION_INFO, *info)) {
+        g_free(*info);
+        return -errno;
+    }
+
+    return 0;
+}
+
 static int vfio_container_do_ioctl(AddressSpace *as, int32_t groupid,
                                    int req, void *param)
 {
diff --git a/hw/vfio/pci-quirks.c b/hw/vfio/pci-quirks.c
index 48155277c6..49ecf1172a 100644
--- a/hw/vfio/pci-quirks.c
+++ b/hw/vfio/pci-quirks.c
@@ -290,10 +290,10 @@ static void vfio_vga_probe_ati_3c3_quirk(VFIOPCIDevice *vdev)
 
     memory_region_init_io(quirk->mem, OBJECT(vdev), &vfio_ati_3c3_quirk, vdev,
                           "vfio-ati-3c3-quirk", 1);
-    memory_region_add_subregion(&vdev->vga.region[QEMU_PCI_VGA_IO_HI].mem,
+    memory_region_add_subregion(&vdev->vga->region[QEMU_PCI_VGA_IO_HI].mem,
                                 3 /* offset 3 bytes from 0x3c0 */, quirk->mem);
 
-    QLIST_INSERT_HEAD(&vdev->vga.region[QEMU_PCI_VGA_IO_HI].quirks,
+    QLIST_INSERT_HEAD(&vdev->vga->region[QEMU_PCI_VGA_IO_HI].quirks,
                       quirk, next);
 
     trace_vfio_quirk_ati_3c3_probe(vdev->vbasedev.name);
@@ -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);
@@ -428,7 +428,7 @@ static uint64_t vfio_nvidia_3d4_quirk_read(void *opaque,
 
     quirk->state = NONE;
 
-    return vfio_vga_read(&vdev->vga.region[QEMU_PCI_VGA_IO_HI],
+    return vfio_vga_read(&vdev->vga->region[QEMU_PCI_VGA_IO_HI],
                          addr + 0x14, size);
 }
 
@@ -465,7 +465,7 @@ static void vfio_nvidia_3d4_quirk_write(void *opaque, hwaddr addr,
         break;
     }
 
-    vfio_vga_write(&vdev->vga.region[QEMU_PCI_VGA_IO_HI],
+    vfio_vga_write(&vdev->vga->region[QEMU_PCI_VGA_IO_HI],
                    addr + 0x14, data, size);
 }
 
@@ -481,7 +481,7 @@ static uint64_t vfio_nvidia_3d0_quirk_read(void *opaque,
     VFIONvidia3d0Quirk *quirk = opaque;
     VFIOPCIDevice *vdev = quirk->vdev;
     VFIONvidia3d0State old_state = quirk->state;
-    uint64_t data = vfio_vga_read(&vdev->vga.region[QEMU_PCI_VGA_IO_HI],
+    uint64_t data = vfio_vga_read(&vdev->vga->region[QEMU_PCI_VGA_IO_HI],
                                   addr + 0x10, size);
 
     quirk->state = NONE;
@@ -523,7 +523,7 @@ static void vfio_nvidia_3d0_quirk_write(void *opaque, hwaddr addr,
         }
     }
 
-    vfio_vga_write(&vdev->vga.region[QEMU_PCI_VGA_IO_HI],
+    vfio_vga_write(&vdev->vga->region[QEMU_PCI_VGA_IO_HI],
                    addr + 0x10, data, size);
 }
 
@@ -551,15 +551,15 @@ static void vfio_vga_probe_nvidia_3d0_quirk(VFIOPCIDevice *vdev)
 
     memory_region_init_io(&quirk->mem[0], OBJECT(vdev), &vfio_nvidia_3d4_quirk,
                           data, "vfio-nvidia-3d4-quirk", 2);
-    memory_region_add_subregion(&vdev->vga.region[QEMU_PCI_VGA_IO_HI].mem,
+    memory_region_add_subregion(&vdev->vga->region[QEMU_PCI_VGA_IO_HI].mem,
                                 0x14 /* 0x3c0 + 0x14 */, &quirk->mem[0]);
 
     memory_region_init_io(&quirk->mem[1], OBJECT(vdev), &vfio_nvidia_3d0_quirk,
                           data, "vfio-nvidia-3d0-quirk", 2);
-    memory_region_add_subregion(&vdev->vga.region[QEMU_PCI_VGA_IO_HI].mem,
+    memory_region_add_subregion(&vdev->vga->region[QEMU_PCI_VGA_IO_HI].mem,
                                 0x10 /* 0x3c0 + 0x10 */, &quirk->mem[1]);
 
-    QLIST_INSERT_HEAD(&vdev->vga.region[QEMU_PCI_VGA_IO_HI].quirks,
+    QLIST_INSERT_HEAD(&vdev->vga->region[QEMU_PCI_VGA_IO_HI].quirks,
                       quirk, next);
 
     trace_vfio_quirk_nvidia_3d0_probe(vdev->vbasedev.name);
@@ -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);
@@ -970,28 +970,28 @@ void vfio_vga_quirk_setup(VFIOPCIDevice *vdev)
     vfio_vga_probe_nvidia_3d0_quirk(vdev);
 }
 
-void vfio_vga_quirk_teardown(VFIOPCIDevice *vdev)
+void vfio_vga_quirk_exit(VFIOPCIDevice *vdev)
 {
     VFIOQuirk *quirk;
     int i, j;
 
-    for (i = 0; i < ARRAY_SIZE(vdev->vga.region); i++) {
-        QLIST_FOREACH(quirk, &vdev->vga.region[i].quirks, next) {
+    for (i = 0; i < ARRAY_SIZE(vdev->vga->region); i++) {
+        QLIST_FOREACH(quirk, &vdev->vga->region[i].quirks, next) {
             for (j = 0; j < quirk->nr_mem; j++) {
-                memory_region_del_subregion(&vdev->vga.region[i].mem,
+                memory_region_del_subregion(&vdev->vga->region[i].mem,
                                             &quirk->mem[j]);
             }
         }
     }
 }
 
-void vfio_vga_quirk_free(VFIOPCIDevice *vdev)
+void vfio_vga_quirk_finalize(VFIOPCIDevice *vdev)
 {
     int i, j;
 
-    for (i = 0; i < ARRAY_SIZE(vdev->vga.region); i++) {
-        while (!QLIST_EMPTY(&vdev->vga.region[i].quirks)) {
-            VFIOQuirk *quirk = QLIST_FIRST(&vdev->vga.region[i].quirks);
+    for (i = 0; i < ARRAY_SIZE(vdev->vga->region); i++) {
+        while (!QLIST_EMPTY(&vdev->vga->region[i].quirks)) {
+            VFIOQuirk *quirk = QLIST_FIRST(&vdev->vga->region[i].quirks);
             QLIST_REMOVE(quirk, next);
             for (j = 0; j < quirk->nr_mem; j++) {
                 object_unparent(OBJECT(&quirk->mem[j]));
@@ -1012,7 +1012,7 @@ void vfio_bar_quirk_setup(VFIOPCIDevice *vdev, int nr)
     vfio_probe_rtl8168_bar2_quirk(vdev, nr);
 }
 
-void vfio_bar_quirk_teardown(VFIOPCIDevice *vdev, int nr)
+void vfio_bar_quirk_exit(VFIOPCIDevice *vdev, int nr)
 {
     VFIOBAR *bar = &vdev->bars[nr];
     VFIOQuirk *quirk;
@@ -1020,12 +1020,12 @@ 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]);
         }
     }
 }
 
-void vfio_bar_quirk_free(VFIOPCIDevice *vdev, int nr)
+void vfio_bar_quirk_finalize(VFIOPCIDevice *vdev, int nr)
 {
     VFIOBAR *bar = &vdev->bars[nr];
     int i;
diff --git a/hw/vfio/pci.c b/hw/vfio/pci.c
index 20b505f4ec..d091d8cf0e 100644
--- a/hw/vfio/pci.c
+++ b/hw/vfio/pci.c
@@ -783,25 +783,25 @@ static void vfio_update_msi(VFIOPCIDevice *vdev)
 
 static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
 {
-    struct vfio_region_info reg_info = {
-        .argsz = sizeof(reg_info),
-        .index = VFIO_PCI_ROM_REGION_INDEX
-    };
+    struct vfio_region_info *reg_info;
     uint64_t size;
     off_t off = 0;
     ssize_t bytes;
 
-    if (ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info)) {
+    if (vfio_get_region_info(&vdev->vbasedev,
+                             VFIO_PCI_ROM_REGION_INDEX, &reg_info)) {
         error_report("vfio: Error getting ROM info: %m");
         return;
     }
 
-    trace_vfio_pci_load_rom(vdev->vbasedev.name, (unsigned long)reg_info.size,
-                            (unsigned long)reg_info.offset,
-                            (unsigned long)reg_info.flags);
+    trace_vfio_pci_load_rom(vdev->vbasedev.name, (unsigned long)reg_info->size,
+                            (unsigned long)reg_info->offset,
+                            (unsigned long)reg_info->flags);
 
-    vdev->rom_size = size = reg_info.size;
-    vdev->rom_offset = reg_info.offset;
+    vdev->rom_size = size = reg_info->size;
+    vdev->rom_offset = reg_info->offset;
+
+    g_free(reg_info);
 
     if (!vdev->rom_size) {
         vdev->rom_read_failed = true;
@@ -832,6 +832,36 @@ static void vfio_pci_load_rom(VFIOPCIDevice *vdev)
             break;
         }
     }
+
+    /*
+     * Test the ROM signature against our device, if the vendor is correct
+     * but the device ID doesn't match, store the correct device ID and
+     * recompute the checksum.  Intel IGD devices need this and are known
+     * to have bogus checksums so we can't simply adjust the checksum.
+     */
+    if (pci_get_word(vdev->rom) == 0xaa55 &&
+        pci_get_word(vdev->rom + 0x18) + 8 < vdev->rom_size &&
+        !memcmp(vdev->rom + pci_get_word(vdev->rom + 0x18), "PCIR", 4)) {
+        uint16_t vid, did;
+
+        vid = pci_get_word(vdev->rom + pci_get_word(vdev->rom + 0x18) + 4);
+        did = pci_get_word(vdev->rom + pci_get_word(vdev->rom + 0x18) + 6);
+
+        if (vid == vdev->vendor_id && did != vdev->device_id) {
+            int i;
+            uint8_t csum, *data = vdev->rom;
+
+            pci_set_word(vdev->rom + pci_get_word(vdev->rom + 0x18) + 6,
+                         vdev->device_id);
+            data[6] = 0;
+
+            for (csum = 0, i = 0; i < vdev->rom_size; i++) {
+                csum += data[i];
+            }
+
+            data[6] = -csum;
+        }
+    }
 }
 
 static uint64_t vfio_rom_read(void *opaque, hwaddr addr, unsigned size)
@@ -889,18 +919,14 @@ static void vfio_pci_size_rom(VFIOPCIDevice *vdev)
     uint32_t orig, size = cpu_to_le32((uint32_t)PCI_ROM_ADDRESS_MASK);
     off_t offset = vdev->config_offset + PCI_ROM_ADDRESS;
     DeviceState *dev = DEVICE(vdev);
-    char name[32];
+    char *name;
     int fd = vdev->vbasedev.fd;
 
     if (vdev->pdev.romfile || !vdev->pdev.rom_bar) {
         /* Since pci handles romfile, just print a message and return */
         if (vfio_blacklist_opt_rom(vdev) && vdev->pdev.romfile) {
-            error_printf("Warning : Device at %04x:%02x:%02x.%x "
-                         "is known to cause system instability issues during "
-                         "option rom execution. "
-                         "Proceeding anyway since user specified romfile\n",
-                         vdev->host.domain, vdev->host.bus, vdev->host.slot,
-                         vdev->host.function);
+            error_printf("Warning : Device at %s is known to cause system instability issues during option rom execution. Proceeding anyway since user specified romfile\n",
+                         vdev->vbasedev.name);
         }
         return;
     }
@@ -913,9 +939,7 @@ static void vfio_pci_size_rom(VFIOPCIDevice *vdev)
         pwrite(fd, &size, 4, offset) != 4 ||
         pread(fd, &size, 4, offset) != 4 ||
         pwrite(fd, &orig, 4, offset) != 4) {
-        error_report("%s(%04x:%02x:%02x.%x) failed: %m",
-                     __func__, vdev->host.domain, vdev->host.bus,
-                     vdev->host.slot, vdev->host.function);
+        error_report("%s(%s) failed: %m", __func__, vdev->vbasedev.name);
         return;
     }
 
@@ -927,32 +951,22 @@ static void vfio_pci_size_rom(VFIOPCIDevice *vdev)
 
     if (vfio_blacklist_opt_rom(vdev)) {
         if (dev->opts && qemu_opt_get(dev->opts, "rombar")) {
-            error_printf("Warning : Device at %04x:%02x:%02x.%x "
-                         "is known to cause system instability issues during "
-                         "option rom execution. "
-                         "Proceeding anyway since user specified non zero value for "
-                         "rombar\n",
-                         vdev->host.domain, vdev->host.bus, vdev->host.slot,
-                         vdev->host.function);
+            error_printf("Warning : Device at %s is known to cause system instability issues during option rom execution. Proceeding anyway since user specified non zero value for rombar\n",
+                         vdev->vbasedev.name);
         } else {
-            error_printf("Warning : Rom loading for device at "
-                         "%04x:%02x:%02x.%x has been disabled due to "
-                         "system instability issues. "
-                         "Specify rombar=1 or romfile to force\n",
-                         vdev->host.domain, vdev->host.bus, vdev->host.slot,
-                         vdev->host.function);
+            error_printf("Warning : Rom loading for device at %s has been disabled due to system instability issues. Specify rombar=1 or romfile to force\n",
+                         vdev->vbasedev.name);
             return;
         }
     }
 
     trace_vfio_pci_size_rom(vdev->vbasedev.name, size);
 
-    snprintf(name, sizeof(name), "vfio[%04x:%02x:%02x.%x].rom",
-             vdev->host.domain, vdev->host.bus, vdev->host.slot,
-             vdev->host.function);
+    name = g_strdup_printf("vfio[%s].rom", vdev->vbasedev.name);
 
     memory_region_init_io(&vdev->pdev.rom, OBJECT(vdev),
                           &vfio_rom_ops, vdev, name, size);
+    g_free(name);
 
     pci_register_bar(&vdev->pdev, PCI_ROM_SLOT,
                      PCI_BASE_ADDRESS_SPACE_MEMORY, &vdev->pdev.rom);
@@ -1063,9 +1077,8 @@ uint32_t vfio_pci_read_config(PCIDevice *pdev, uint32_t addr, int len)
         ret = pread(vdev->vbasedev.fd, &phys_val, len,
                     vdev->config_offset + addr);
         if (ret != len) {
-            error_report("%s(%04x:%02x:%02x.%x, 0x%x, 0x%x) failed: %m",
-                         __func__, vdev->host.domain, vdev->host.bus,
-                         vdev->host.slot, vdev->host.function, addr, len);
+            error_report("%s(%s, 0x%x, 0x%x) failed: %m",
+                         __func__, vdev->vbasedev.name, addr, len);
             return -errno;
         }
         phys_val = le32_to_cpu(phys_val);
@@ -1089,9 +1102,8 @@ void vfio_pci_write_config(PCIDevice *pdev,
     /* Write everything to VFIO, let it filter out what we can't write */
     if (pwrite(vdev->vbasedev.fd, &val_le, len, vdev->config_offset + addr)
                 != len) {
-        error_report("%s(%04x:%02x:%02x.%x, 0x%x, 0x%x, 0x%x) failed: %m",
-                     __func__, vdev->host.domain, vdev->host.bus,
-                     vdev->host.slot, vdev->host.function, addr, val, len);
+        error_report("%s(%s, 0x%x, 0x%x, 0x%x) failed: %m",
+                     __func__, vdev->vbasedev.name, addr, val, len);
     }
 
     /* MSI/MSI-X Enabling/Disabling */
@@ -1185,6 +1197,74 @@ 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
@@ -1259,6 +1339,8 @@ static int vfio_msix_early_setup(VFIOPCIDevice *vdev)
                                 msix->table_offset, msix->entries);
     vdev->msix = msix;
 
+    vfio_pci_fixup_msix_region(vdev);
+
     return 0;
 }
 
@@ -1269,9 +1351,9 @@ 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) {
@@ -1308,8 +1390,8 @@ 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);
     }
 }
@@ -1322,71 +1404,23 @@ 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);
     }
 }
 
-static void vfio_unregister_bar(VFIOPCIDevice *vdev, int nr)
+static void vfio_bar_setup(VFIOPCIDevice *vdev, int nr)
 {
     VFIOBAR *bar = &vdev->bars[nr];
 
-    if (!bar->region.size) {
-        return;
-    }
-
-    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);
-    }
-}
-
-static void vfio_unmap_bar(VFIOPCIDevice *vdev, int nr)
-{
-    VFIOBAR *bar = &vdev->bars[nr];
-
-    if (!bar->region.size) {
-        return;
-    }
-
-    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));
-    }
-}
-
-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;
 
     /* Skip both unimplemented BARs and the upper half of 64bit BARS. */
-    if (!size) {
+    if (!bar->region.size) {
         return;
     }
 
-    snprintf(name, sizeof(name), "VFIO %04x:%02x:%02x.%x BAR %d",
-             vdev->host.domain, vdev->host.bus, vdev->host.slot,
-             vdev->host.function, 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));
@@ -1401,102 +1435,78 @@ 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));
-
-        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);
+
+    pci_register_bar(&vdev->pdev, nr, type, bar->region.mem);
 }
 
-static void vfio_map_bars(VFIOPCIDevice *vdev)
+static void vfio_bars_setup(VFIOPCIDevice *vdev)
 {
     int i;
 
     for (i = 0; i < PCI_ROM_SLOT; i++) {
-        vfio_map_bar(vdev, i);
+        vfio_bar_setup(vdev, i);
     }
 
-    if (vdev->has_vga) {
-        memory_region_init_io(&vdev->vga.region[QEMU_PCI_VGA_MEM].mem,
+    if (vdev->vga) {
+        memory_region_init_io(&vdev->vga->region[QEMU_PCI_VGA_MEM].mem,
                               OBJECT(vdev), &vfio_vga_ops,
-                              &vdev->vga.region[QEMU_PCI_VGA_MEM],
+                              &vdev->vga->region[QEMU_PCI_VGA_MEM],
                               "vfio-vga-mmio@0xa0000",
                               QEMU_PCI_VGA_MEM_SIZE);
-        memory_region_init_io(&vdev->vga.region[QEMU_PCI_VGA_IO_LO].mem,
+        memory_region_init_io(&vdev->vga->region[QEMU_PCI_VGA_IO_LO].mem,
                               OBJECT(vdev), &vfio_vga_ops,
-                              &vdev->vga.region[QEMU_PCI_VGA_IO_LO],
+                              &vdev->vga->region[QEMU_PCI_VGA_IO_LO],
                               "vfio-vga-io@0x3b0",
                               QEMU_PCI_VGA_IO_LO_SIZE);
-        memory_region_init_io(&vdev->vga.region[QEMU_PCI_VGA_IO_HI].mem,
+        memory_region_init_io(&vdev->vga->region[QEMU_PCI_VGA_IO_HI].mem,
                               OBJECT(vdev), &vfio_vga_ops,
-                              &vdev->vga.region[QEMU_PCI_VGA_IO_HI],
+                              &vdev->vga->region[QEMU_PCI_VGA_IO_HI],
                               "vfio-vga-io@0x3c0",
                               QEMU_PCI_VGA_IO_HI_SIZE);
 
-        pci_register_vga(&vdev->pdev, &vdev->vga.region[QEMU_PCI_VGA_MEM].mem,
-                         &vdev->vga.region[QEMU_PCI_VGA_IO_LO].mem,
-                         &vdev->vga.region[QEMU_PCI_VGA_IO_HI].mem);
+        pci_register_vga(&vdev->pdev, &vdev->vga->region[QEMU_PCI_VGA_MEM].mem,
+                         &vdev->vga->region[QEMU_PCI_VGA_IO_LO].mem,
+                         &vdev->vga->region[QEMU_PCI_VGA_IO_HI].mem);
         vfio_vga_quirk_setup(vdev);
     }
 }
 
-static void vfio_unregister_bars(VFIOPCIDevice *vdev)
+static void vfio_bars_exit(VFIOPCIDevice *vdev)
 {
     int i;
 
     for (i = 0; i < PCI_ROM_SLOT; i++) {
-        vfio_unregister_bar(vdev, i);
+        vfio_bar_quirk_exit(vdev, i);
+        vfio_region_exit(&vdev->bars[i].region);
     }
 
-    if (vdev->has_vga) {
-        vfio_vga_quirk_teardown(vdev);
+    if (vdev->vga) {
         pci_unregister_vga(&vdev->pdev);
+        vfio_vga_quirk_exit(vdev);
     }
 }
 
-static void vfio_unmap_bars(VFIOPCIDevice *vdev)
+static void vfio_bars_finalize(VFIOPCIDevice *vdev)
 {
     int i;
 
     for (i = 0; i < PCI_ROM_SLOT; i++) {
-        vfio_unmap_bar(vdev, i);
+        vfio_bar_quirk_finalize(vdev, i);
+        vfio_region_finalize(&vdev->bars[i].region);
     }
 
-    if (vdev->has_vga) {
-        vfio_vga_quirk_free(vdev);
+    if (vdev->vga) {
+        vfio_vga_quirk_finalize(vdev);
+        for (i = 0; i < ARRAY_SIZE(vdev->vga->region); i++) {
+            object_unparent(OBJECT(&vdev->vga->region[i].mem));
+        }
+        g_free(vdev->vga);
     }
 }
 
@@ -1756,9 +1766,8 @@ static int vfio_add_std_cap(VFIOPCIDevice *vdev, uint8_t pos)
     }
 
     if (ret < 0) {
-        error_report("vfio: %04x:%02x:%02x.%x Error adding PCI capability "
-                     "0x%x[0x%x]@0x%x: %d", vdev->host.domain,
-                     vdev->host.bus, vdev->host.slot, vdev->host.function,
+        error_report("vfio: %s Error adding PCI capability "
+                     "0x%x[0x%x]@0x%x: %d", vdev->vbasedev.name,
                      cap_id, size, pos, ret);
         return ret;
     }
@@ -1820,11 +1829,14 @@ static void vfio_pci_post_reset(VFIOPCIDevice *vdev)
     vfio_intx_enable(vdev);
 }
 
-static bool vfio_pci_host_match(PCIHostDeviceAddress *host1,
-                                PCIHostDeviceAddress *host2)
+static bool vfio_pci_host_match(PCIHostDeviceAddress *addr, const char *name)
 {
-    return (host1->domain == host2->domain && host1->bus == host2->bus &&
-            host1->slot == host2->slot && host1->function == host2->function);
+    char tmp[13];
+
+    sprintf(tmp, "%04x:%02x:%02x.%1x", addr->domain,
+            addr->bus, addr->slot, addr->function);
+
+    return (strcmp(tmp, name) == 0);
 }
 
 static int vfio_pci_hot_reset(VFIOPCIDevice *vdev, bool single)
@@ -1849,9 +1861,8 @@ static int vfio_pci_hot_reset(VFIOPCIDevice *vdev, bool single)
     if (ret && errno != ENOSPC) {
         ret = -errno;
         if (!vdev->has_pm_reset) {
-            error_report("vfio: Cannot reset device %04x:%02x:%02x.%x, "
-                         "no available reset mechanism.", vdev->host.domain,
-                         vdev->host.bus, vdev->host.slot, vdev->host.function);
+            error_report("vfio: Cannot reset device %s, "
+                         "no available reset mechanism.", vdev->vbasedev.name);
         }
         goto out_single;
     }
@@ -1884,7 +1895,7 @@ static int vfio_pci_hot_reset(VFIOPCIDevice *vdev, bool single)
         trace_vfio_pci_hot_reset_dep_devices(host.domain,
                 host.bus, host.slot, host.function, devices[i].group_id);
 
-        if (vfio_pci_host_match(&host, &vdev->host)) {
+        if (vfio_pci_host_match(&host, vdev->vbasedev.name)) {
             continue;
         }
 
@@ -1910,7 +1921,7 @@ static int vfio_pci_hot_reset(VFIOPCIDevice *vdev, bool single)
                 continue;
             }
             tmp = container_of(vbasedev_iter, VFIOPCIDevice, vbasedev);
-            if (vfio_pci_host_match(&host, &tmp->host)) {
+            if (vfio_pci_host_match(&host, tmp->vbasedev.name)) {
                 if (single) {
                     ret = -EINVAL;
                     goto out_single;
@@ -1972,7 +1983,7 @@ out:
         host.slot = PCI_SLOT(devices[i].devfn);
         host.function = PCI_FUNC(devices[i].devfn);
 
-        if (vfio_pci_host_match(&host, &vdev->host)) {
+        if (vfio_pci_host_match(&host, vdev->vbasedev.name)) {
             continue;
         }
 
@@ -1991,7 +2002,7 @@ out:
                 continue;
             }
             tmp = container_of(vbasedev_iter, VFIOPCIDevice, vbasedev);
-            if (vfio_pci_host_match(&host, &tmp->host)) {
+            if (vfio_pci_host_match(&host, tmp->vbasedev.name)) {
                 vfio_pci_post_reset(tmp);
                 break;
             }
@@ -2044,10 +2055,56 @@ static VFIODeviceOps vfio_pci_ops = {
     .vfio_eoi = vfio_intx_eoi,
 };
 
+int vfio_populate_vga(VFIOPCIDevice *vdev)
+{
+    VFIODevice *vbasedev = &vdev->vbasedev;
+    struct vfio_region_info *reg_info;
+    int ret;
+
+    if (vbasedev->num_regions > VFIO_PCI_VGA_REGION_INDEX) {
+        ret = vfio_get_region_info(vbasedev,
+                                   VFIO_PCI_VGA_REGION_INDEX, &reg_info);
+        if (ret) {
+            return ret;
+        }
+
+        if (!(reg_info->flags & VFIO_REGION_INFO_FLAG_READ) ||
+            !(reg_info->flags & VFIO_REGION_INFO_FLAG_WRITE) ||
+            reg_info->size < 0xbffff + 1) {
+            error_report("vfio: Unexpected VGA info, flags 0x%lx, size 0x%lx",
+                         (unsigned long)reg_info->flags,
+                         (unsigned long)reg_info->size);
+            g_free(reg_info);
+            return -EINVAL;
+        }
+
+        vdev->vga = g_new0(VFIOVGA, 1);
+
+        vdev->vga->fd_offset = reg_info->offset;
+        vdev->vga->fd = vdev->vbasedev.fd;
+
+        g_free(reg_info);
+
+        vdev->vga->region[QEMU_PCI_VGA_MEM].offset = QEMU_PCI_VGA_MEM_BASE;
+        vdev->vga->region[QEMU_PCI_VGA_MEM].nr = QEMU_PCI_VGA_MEM;
+        QLIST_INIT(&vdev->vga->region[QEMU_PCI_VGA_MEM].quirks);
+
+        vdev->vga->region[QEMU_PCI_VGA_IO_LO].offset = QEMU_PCI_VGA_IO_LO_BASE;
+        vdev->vga->region[QEMU_PCI_VGA_IO_LO].nr = QEMU_PCI_VGA_IO_LO;
+        QLIST_INIT(&vdev->vga->region[QEMU_PCI_VGA_IO_LO].quirks);
+
+        vdev->vga->region[QEMU_PCI_VGA_IO_HI].offset = QEMU_PCI_VGA_IO_HI_BASE;
+        vdev->vga->region[QEMU_PCI_VGA_IO_HI].nr = QEMU_PCI_VGA_IO_HI;
+        QLIST_INIT(&vdev->vga->region[QEMU_PCI_VGA_IO_HI].quirks);
+    }
+
+    return 0;
+}
+
 static int vfio_populate_device(VFIOPCIDevice *vdev)
 {
     VFIODevice *vbasedev = &vdev->vbasedev;
-    struct vfio_region_info reg_info = { .argsz = sizeof(reg_info) };
+    struct vfio_region_info *reg_info;
     struct vfio_irq_info irq_info = { .argsz = sizeof(irq_info) };
     int i, ret = -1;
 
@@ -2069,85 +2126,47 @@ static int vfio_populate_device(VFIOPCIDevice *vdev)
     }
 
     for (i = VFIO_PCI_BAR0_REGION_INDEX; i < VFIO_PCI_ROM_REGION_INDEX; i++) {
-        reg_info.index = i;
+        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);
 
-        ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
         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);
     }
 
-    reg_info.index = VFIO_PCI_CONFIG_REGION_INDEX;
-
-    ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_REGION_INFO, &reg_info);
+    ret = vfio_get_region_info(vbasedev,
+                               VFIO_PCI_CONFIG_REGION_INDEX, &reg_info);
     if (ret) {
         error_report("vfio: Error getting config info: %m");
         goto error;
     }
 
     trace_vfio_populate_device_config(vdev->vbasedev.name,
-                                      (unsigned long)reg_info.size,
-                                      (unsigned long)reg_info.offset,
-                                      (unsigned long)reg_info.flags);
+                                      (unsigned long)reg_info->size,
+                                      (unsigned long)reg_info->offset,
+                                      (unsigned long)reg_info->flags);
 
-    vdev->config_size = reg_info.size;
+    vdev->config_size = reg_info->size;
     if (vdev->config_size == PCI_CONFIG_SPACE_SIZE) {
         vdev->pdev.cap_present &= ~QEMU_PCI_CAP_EXPRESS;
     }
-    vdev->config_offset = reg_info.offset;
+    vdev->config_offset = reg_info->offset;
 
-    if ((vdev->features & VFIO_FEATURE_ENABLE_VGA) &&
-        vbasedev->num_regions > VFIO_PCI_VGA_REGION_INDEX) {
-        struct vfio_region_info vga_info = {
-            .argsz = sizeof(vga_info),
-            .index = VFIO_PCI_VGA_REGION_INDEX,
-         };
+    g_free(reg_info);
 
-        ret = ioctl(vdev->vbasedev.fd, VFIO_DEVICE_GET_REGION_INFO, &vga_info);
+    if (vdev->features & VFIO_FEATURE_ENABLE_VGA) {
+        ret = vfio_populate_vga(vdev);
         if (ret) {
             error_report(
                 "vfio: Device does not support requested feature x-vga");
             goto error;
         }
-
-        if (!(vga_info.flags & VFIO_REGION_INFO_FLAG_READ) ||
-            !(vga_info.flags & VFIO_REGION_INFO_FLAG_WRITE) ||
-            vga_info.size < 0xbffff + 1) {
-            error_report("vfio: Unexpected VGA info, flags 0x%lx, size 0x%lx",
-                         (unsigned long)vga_info.flags,
-                         (unsigned long)vga_info.size);
-            goto error;
-        }
-
-        vdev->vga.fd_offset = vga_info.offset;
-        vdev->vga.fd = vdev->vbasedev.fd;
-
-        vdev->vga.region[QEMU_PCI_VGA_MEM].offset = QEMU_PCI_VGA_MEM_BASE;
-        vdev->vga.region[QEMU_PCI_VGA_MEM].nr = QEMU_PCI_VGA_MEM;
-        QLIST_INIT(&vdev->vga.region[QEMU_PCI_VGA_MEM].quirks);
-
-        vdev->vga.region[QEMU_PCI_VGA_IO_LO].offset = QEMU_PCI_VGA_IO_LO_BASE;
-        vdev->vga.region[QEMU_PCI_VGA_IO_LO].nr = QEMU_PCI_VGA_IO_LO;
-        QLIST_INIT(&vdev->vga.region[QEMU_PCI_VGA_IO_LO].quirks);
-
-        vdev->vga.region[QEMU_PCI_VGA_IO_HI].offset = QEMU_PCI_VGA_IO_HI_BASE;
-        vdev->vga.region[QEMU_PCI_VGA_IO_HI].nr = QEMU_PCI_VGA_IO_HI;
-        QLIST_INIT(&vdev->vga.region[QEMU_PCI_VGA_IO_HI].quirks);
-
-        vdev->has_vga = true;
     }
 
     irq_info.index = VFIO_PCI_ERR_IRQ_INDEX;
@@ -2172,11 +2191,8 @@ 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);
 }
 
@@ -2197,10 +2213,7 @@ static void vfio_err_notifier_handler(void *opaque)
      * guest to contain the error.
      */
 
-    error_report("%s(%04x:%02x:%02x.%x) Unrecoverable error detected.  "
-                 "Please collect any data possible and then kill the guest",
-                 __func__, vdev->host.domain, vdev->host.bus,
-                 vdev->host.slot, vdev->host.function);
+    error_report("%s(%s) Unrecoverable error detected. Please collect any data possible and then kill the guest", __func__, vdev->vbasedev.name);
 
     vm_stop(RUN_STATE_INTERNAL_ERROR);
 }
@@ -2381,42 +2394,43 @@ static int vfio_initfn(PCIDevice *pdev)
     VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pdev);
     VFIODevice *vbasedev_iter;
     VFIOGroup *group;
-    char path[PATH_MAX], iommu_group_path[PATH_MAX], *group_name;
+    char *tmp, group_path[PATH_MAX], *group_name;
     ssize_t len;
     struct stat st;
     int groupid;
     int ret;
 
-    /* Check that the host device exists */
-    snprintf(path, sizeof(path),
-             "/sys/bus/pci/devices/%04x:%02x:%02x.%01x/",
-             vdev->host.domain, vdev->host.bus, vdev->host.slot,
-             vdev->host.function);
-    if (stat(path, &st) < 0) {
-        error_report("vfio: error: no such host device: %s", path);
+    if (!vdev->vbasedev.sysfsdev) {
+        vdev->vbasedev.sysfsdev =
+            g_strdup_printf("/sys/bus/pci/devices/%04x:%02x:%02x.%01x",
+                            vdev->host.domain, vdev->host.bus,
+                            vdev->host.slot, vdev->host.function);
+    }
+
+    if (stat(vdev->vbasedev.sysfsdev, &st) < 0) {
+        error_report("vfio: error: no such host device: %s",
+                     vdev->vbasedev.sysfsdev);
         return -errno;
     }
 
+    vdev->vbasedev.name = g_strdup(basename(vdev->vbasedev.sysfsdev));
     vdev->vbasedev.ops = &vfio_pci_ops;
-
     vdev->vbasedev.type = VFIO_DEVICE_TYPE_PCI;
-    vdev->vbasedev.name = g_strdup_printf("%04x:%02x:%02x.%01x",
-                                          vdev->host.domain, vdev->host.bus,
-                                          vdev->host.slot, vdev->host.function);
 
-    strncat(path, "iommu_group", sizeof(path) - strlen(path) - 1);
+    tmp = g_strdup_printf("%s/iommu_group", vdev->vbasedev.sysfsdev);
+    len = readlink(tmp, group_path, sizeof(group_path));
+    g_free(tmp);
 
-    len = readlink(path, iommu_group_path, sizeof(path));
-    if (len <= 0 || len >= sizeof(path)) {
+    if (len <= 0 || len >= sizeof(group_path)) {
         error_report("vfio: error no iommu_group for device");
         return len < 0 ? -errno : -ENAMETOOLONG;
     }
 
-    iommu_group_path[len] = 0;
-    group_name = basename(iommu_group_path);
+    group_path[len] = 0;
 
+    group_name = basename(group_path);
     if (sscanf(group_name, "%d", &groupid) != 1) {
-        error_report("vfio: error reading %s: %m", path);
+        error_report("vfio: error reading %s: %m", group_path);
         return -errno;
     }
 
@@ -2428,21 +2442,18 @@ static int vfio_initfn(PCIDevice *pdev)
         return -ENOENT;
     }
 
-    snprintf(path, sizeof(path), "%04x:%02x:%02x.%01x",
-            vdev->host.domain, vdev->host.bus, vdev->host.slot,
-            vdev->host.function);
-
     QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
         if (strcmp(vbasedev_iter->name, vdev->vbasedev.name) == 0) {
-            error_report("vfio: error: device %s is already attached", path);
+            error_report("vfio: error: device %s is already attached",
+                         vdev->vbasedev.name);
             vfio_put_group(group);
             return -EBUSY;
         }
     }
 
-    ret = vfio_get_device(group, path, &vdev->vbasedev);
+    ret = vfio_get_device(group, vdev->vbasedev.name, &vdev->vbasedev);
     if (ret) {
-        error_report("vfio: failed to get device %s", path);
+        error_report("vfio: failed to get device %s", vdev->vbasedev.name);
         vfio_put_group(group);
         return ret;
     }
@@ -2542,7 +2553,7 @@ static int vfio_initfn(PCIDevice *pdev)
         return ret;
     }
 
-    vfio_map_bars(vdev);
+    vfio_bars_setup(vdev);
 
     ret = vfio_add_capabilities(vdev);
     if (ret) {
@@ -2579,7 +2590,7 @@ static int vfio_initfn(PCIDevice *pdev)
 out_teardown:
     pci_device_set_intx_routing_notifier(&vdev->pdev, NULL);
     vfio_teardown_msi(vdev);
-    vfio_unregister_bars(vdev);
+    vfio_bars_exit(vdev);
     return ret;
 }
 
@@ -2589,7 +2600,7 @@ static void vfio_instance_finalize(Object *obj)
     VFIOPCIDevice *vdev = DO_UPCAST(VFIOPCIDevice, pdev, pci_dev);
     VFIOGroup *group = vdev->vbasedev.group;
 
-    vfio_unmap_bars(vdev);
+    vfio_bars_finalize(vdev);
     g_free(vdev->emulated_config_bits);
     g_free(vdev->rom);
     vfio_put_device(vdev);
@@ -2608,7 +2619,7 @@ static void vfio_exitfn(PCIDevice *pdev)
         timer_free(vdev->intx.mmap_timer);
     }
     vfio_teardown_msi(vdev);
-    vfio_unregister_bars(vdev);
+    vfio_bars_exit(vdev);
 }
 
 static void vfio_pci_reset(DeviceState *dev)
@@ -2659,6 +2670,7 @@ static void vfio_instance_init(Object *obj)
 
 static Property vfio_pci_dev_properties[] = {
     DEFINE_PROP_PCI_HOST_DEVADDR("host", VFIOPCIDevice, host),
+    DEFINE_PROP_STRING("sysfsdev", VFIOPCIDevice, vbasedev.sysfsdev),
     DEFINE_PROP_UINT32("x-intx-mmap-timeout-ms", VFIOPCIDevice,
                        intx.mmap_timeout, 1100),
     DEFINE_PROP_BIT("x-vga", VFIOPCIDevice, features,
diff --git a/hw/vfio/pci.h b/hw/vfio/pci.h
index 62565878fc..3976f68549 100644
--- a/hw/vfio/pci.h
+++ b/hw/vfio/pci.h
@@ -114,7 +114,7 @@ typedef struct VFIOPCIDevice {
     int nr_vectors; /* Number of MSI/MSIX vectors currently in use */
     int interrupt; /* Current interrupt type */
     VFIOBAR bars[PCI_NUM_REGIONS - 1]; /* No ROM */
-    VFIOVGA vga; /* 0xa0000, 0x3b0, 0x3c0 */
+    VFIOVGA *vga; /* 0xa0000, 0x3b0, 0x3c0 */
     PCIHostDeviceAddress host;
     EventNotifier err_notifier;
     EventNotifier req_notifier;
@@ -150,11 +150,13 @@ void vfio_vga_write(void *opaque, hwaddr addr, uint64_t data, unsigned size);
 
 bool vfio_blacklist_opt_rom(VFIOPCIDevice *vdev);
 void vfio_vga_quirk_setup(VFIOPCIDevice *vdev);
-void vfio_vga_quirk_teardown(VFIOPCIDevice *vdev);
-void vfio_vga_quirk_free(VFIOPCIDevice *vdev);
+void vfio_vga_quirk_exit(VFIOPCIDevice *vdev);
+void vfio_vga_quirk_finalize(VFIOPCIDevice *vdev);
 void vfio_bar_quirk_setup(VFIOPCIDevice *vdev, int nr);
-void vfio_bar_quirk_teardown(VFIOPCIDevice *vdev, int nr);
-void vfio_bar_quirk_free(VFIOPCIDevice *vdev, int nr);
+void vfio_bar_quirk_exit(VFIOPCIDevice *vdev, int nr);
+void vfio_bar_quirk_finalize(VFIOPCIDevice *vdev, int nr);
 void vfio_setup_resetfn_quirk(VFIOPCIDevice *vdev);
 
+int vfio_populate_vga(VFIOPCIDevice *vdev);
+
 #endif /* HW_VFIO_VFIO_PCI_H */
diff --git a/hw/vfio/platform.c b/hw/vfio/platform.c
index ebc9dcbb99..a2ab75d3f2 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);
     }
 }
 
@@ -476,28 +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 = { .argsz = sizeof(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];
-        reg_info.index = i;
-        ret = ioctl(vbasedev->fd, VFIO_DEVICE_GET_REGION_INFO, &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;
-
-        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,
@@ -534,6 +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);
@@ -560,38 +547,45 @@ static int vfio_base_device_init(VFIODevice *vbasedev)
 {
     VFIOGroup *group;
     VFIODevice *vbasedev_iter;
-    char path[PATH_MAX], iommu_group_path[PATH_MAX], *group_name;
+    char *tmp, group_path[PATH_MAX], *group_name;
     ssize_t len;
     struct stat st;
     int groupid;
     int ret;
 
-    /* name must be set prior to the call */
-    if (!vbasedev->name || strchr(vbasedev->name, '/')) {
-        return -EINVAL;
+    /* @sysfsdev takes precedence over @host */
+    if (vbasedev->sysfsdev) {
+        g_free(vbasedev->name);
+        vbasedev->name = g_strdup(basename(vbasedev->sysfsdev));
+    } else {
+        if (!vbasedev->name || strchr(vbasedev->name, '/')) {
+            return -EINVAL;
+        }
+
+        vbasedev->sysfsdev = g_strdup_printf("/sys/bus/platform/devices/%s",
+                                             vbasedev->name);
     }
 
-    /* Check that the host device exists */
-    g_snprintf(path, sizeof(path), "/sys/bus/platform/devices/%s/",
-               vbasedev->name);
-
-    if (stat(path, &st) < 0) {
-        error_report("vfio: error: no such host device: %s", path);
+    if (stat(vbasedev->sysfsdev, &st) < 0) {
+        error_report("vfio: error: no such host device: %s",
+                     vbasedev->sysfsdev);
         return -errno;
     }
 
-    g_strlcat(path, "iommu_group", sizeof(path));
-    len = readlink(path, iommu_group_path, sizeof(iommu_group_path));
-    if (len < 0 || len >= sizeof(iommu_group_path)) {
+    tmp = g_strdup_printf("%s/iommu_group", vbasedev->sysfsdev);
+    len = readlink(tmp, group_path, sizeof(group_path));
+    g_free(tmp);
+
+    if (len < 0 || len >= sizeof(group_path)) {
         error_report("vfio: error no iommu_group for device");
         return len < 0 ? -errno : -ENAMETOOLONG;
     }
 
-    iommu_group_path[len] = 0;
-    group_name = basename(iommu_group_path);
+    group_path[len] = 0;
 
+    group_name = basename(group_path);
     if (sscanf(group_name, "%d", &groupid) != 1) {
-        error_report("vfio: error reading %s: %m", path);
+        error_report("vfio: error reading %s: %m", group_path);
         return -errno;
     }
 
@@ -603,66 +597,30 @@ static int vfio_base_device_init(VFIODevice *vbasedev)
         return -ENOENT;
     }
 
-    g_snprintf(path, sizeof(path), "%s", vbasedev->name);
-
     QLIST_FOREACH(vbasedev_iter, &group->device_list, next) {
         if (strcmp(vbasedev_iter->name, vbasedev->name) == 0) {
-            error_report("vfio: error: device %s is already attached", path);
+            error_report("vfio: error: device %s is already attached",
+                         vbasedev->name);
             vfio_put_group(group);
             return -EBUSY;
         }
     }
-    ret = vfio_get_device(group, path, vbasedev);
+    ret = vfio_get_device(group, vbasedev->name, vbasedev);
     if (ret) {
-        error_report("vfio: failed to get device %s", path);
+        error_report("vfio: failed to get device %s", vbasedev->name);
         vfio_put_group(group);
         return ret;
     }
 
     ret = vfio_populate_device(vbasedev);
     if (ret) {
-        error_report("vfio: failed to populate device %s", path);
+        error_report("vfio: failed to populate device %s", vbasedev->name);
         vfio_put_group(group);
     }
 
     return ret;
 }
 
-/**
- * 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
@@ -681,7 +639,9 @@ static void vfio_platform_realize(DeviceState *dev, Error **errp)
     vbasedev->type = VFIO_DEVICE_TYPE_PLATFORM;
     vbasedev->ops = &vfio_platform_ops;
 
-    trace_vfio_platform_realize(vbasedev->name, vdev->compat);
+    trace_vfio_platform_realize(vbasedev->sysfsdev ?
+                                vbasedev->sysfsdev : vbasedev->name,
+                                vdev->compat);
 
     ret = vfio_base_device_init(vbasedev);
     if (ret) {
@@ -691,8 +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);
     }
 }
 
@@ -703,6 +666,7 @@ static const VMStateDescription vfio_platform_vmstate = {
 
 static Property vfio_platform_dev_properties[] = {
     DEFINE_PROP_STRING("host", VFIOPlatformDevice, vbasedev.name),
+    DEFINE_PROP_STRING("sysfsdev", VFIOPlatformDevice, vbasedev.sysfsdev),
     DEFINE_PROP_BOOL("x-no-mmap", VFIOPlatformDevice, vbasedev.no_mmap, false),
     DEFINE_PROP_UINT32("mmap-timeout-ms", VFIOPlatformDevice,
                        mmap_timeout, 1100),
diff --git a/include/hw/vfio/vfio-common.h b/include/hw/vfio/vfio-common.h
index f037f3c425..eb0e1b0342 100644
--- a/include/hw/vfio/vfio-common.h
+++ b/include/hw/vfio/vfio-common.h
@@ -25,6 +25,9 @@
 #include "exec/memory.h"
 #include "qemu/queue.h"
 #include "qemu/notify.h"
+#ifdef CONFIG_LINUX
+#include <linux/vfio.h>
+#endif
 
 /*#define DEBUG_VFIO*/
 #ifdef DEBUG_VFIO
@@ -40,14 +43,21 @@ 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;
 
@@ -89,6 +99,7 @@ typedef struct VFIODeviceOps VFIODeviceOps;
 typedef struct VFIODevice {
     QLIST_ENTRY(VFIODevice) next;
     struct VFIOGroup *group;
+    char *sysfsdev;
     char *name;
     int fd;
     int type;
@@ -124,10 +135,12 @@ 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);
@@ -138,4 +151,8 @@ extern const MemoryRegionOps vfio_region_ops;
 extern QLIST_HEAD(vfio_group_head, VFIOGroup) vfio_group_list;
 extern QLIST_HEAD(vfio_as_head, VFIOAddressSpace) vfio_address_spaces;
 
+#ifdef CONFIG_LINUX
+int vfio_get_region_info(VFIODevice *vbasedev, int index,
+                         struct vfio_region_info **info);
+#endif
 #endif /* !HW_VFIO_VFIO_COMMON_H */
diff --git a/trace-events b/trace-events
index 6fba6cc474..bf07a8fa70 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, uint64_t start, uint64_t end) " (%s) MSI-X region %d mmap fixup [0x%"PRIx64" - 0x%"PRIx64"]"
 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)"