diff --git a/hw/mips/gt64xxx_pci.c b/hw/mips/gt64xxx_pci.c
index d2739eb261..5843417567 100644
--- a/hw/mips/gt64xxx_pci.c
+++ b/hw/mips/gt64xxx_pci.c
@@ -1108,7 +1108,7 @@ PCIBus *gt64120_register(qemu_irq *pic)
                                 get_system_memory(),
                                 get_system_io(),
                                 PCI_DEVFN(18, 0), 4, TYPE_PCI_BUS);
-    memory_region_init_io(&d->ISD_mem, NULL, &isd_mem_ops, d, "isd-mem", 0x1000);
+    memory_region_init_io(&d->ISD_mem, OBJECT(dev), &isd_mem_ops, d, "isd-mem", 0x1000);
 
     pci_create_simple(phb->bus, PCI_DEVFN(0, 0), "gt64120_pci");
     return phb->bus;
diff --git a/hw/misc/a9scu.c b/hw/misc/a9scu.c
index c8f26f923a..601b5733f2 100644
--- a/hw/misc/a9scu.c
+++ b/hw/misc/a9scu.c
@@ -119,7 +119,8 @@ static void a9_scu_realize(DeviceState *dev, Error ** errp)
     A9SCUState *s = A9_SCU(dev);
     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
 
-    memory_region_init_io(&s->iomem, NULL, &a9_scu_ops, s, "a9-scu", 0x100);
+    memory_region_init_io(&s->iomem, OBJECT(dev), &a9_scu_ops, s,
+                          "a9-scu", 0x100);
     sysbus_init_mmio(sbd, &s->iomem);
 }
 
diff --git a/hw/misc/applesmc.c b/hw/misc/applesmc.c
index ca4077f0b9..bfafa518e1 100644
--- a/hw/misc/applesmc.c
+++ b/hw/misc/applesmc.c
@@ -230,12 +230,12 @@ static void applesmc_isa_realize(DeviceState *dev, Error **errp)
 {
     AppleSMCState *s = APPLE_SMC(dev);
 
-    memory_region_init_io(&s->io_data, NULL, &applesmc_data_io_ops, s,
+    memory_region_init_io(&s->io_data, OBJECT(s), &applesmc_data_io_ops, s,
                           "applesmc-data", 4);
     isa_register_ioport(&s->parent_obj, &s->io_data,
                         s->iobase + APPLESMC_DATA_PORT);
 
-    memory_region_init_io(&s->io_cmd, NULL, &applesmc_cmd_io_ops, s,
+    memory_region_init_io(&s->io_cmd, OBJECT(s), &applesmc_cmd_io_ops, s,
                           "applesmc-cmd", 4);
     isa_register_ioport(&s->parent_obj, &s->io_cmd,
                         s->iobase + APPLESMC_CMD_PORT);
diff --git a/hw/misc/arm_l2x0.c b/hw/misc/arm_l2x0.c
index 954343f467..3d6acee695 100644
--- a/hw/misc/arm_l2x0.c
+++ b/hw/misc/arm_l2x0.c
@@ -157,7 +157,8 @@ static int l2x0_priv_init(SysBusDevice *dev)
 {
     l2x0_state *s = FROM_SYSBUS(l2x0_state, dev);
 
-    memory_region_init_io(&s->iomem, NULL, &l2x0_mem_ops, s, "l2x0_cc", 0x1000);
+    memory_region_init_io(&s->iomem, OBJECT(dev), &l2x0_mem_ops, s,
+                          "l2x0_cc", 0x1000);
     sysbus_init_mmio(dev, &s->iomem);
     return 0;
 }
diff --git a/hw/misc/arm_sysctl.c b/hw/misc/arm_sysctl.c
index 9b07355c32..5906ae5869 100644
--- a/hw/misc/arm_sysctl.c
+++ b/hw/misc/arm_sysctl.c
@@ -589,7 +589,8 @@ static void arm_sysctl_init(Object *obj)
     SysBusDevice *sd = SYS_BUS_DEVICE(obj);
     arm_sysctl_state *s = FROM_SYSBUS(arm_sysctl_state, sd);
 
-    memory_region_init_io(&s->iomem, NULL, &arm_sysctl_ops, s, "arm-sysctl", 0x1000);
+    memory_region_init_io(&s->iomem, OBJECT(dev), &arm_sysctl_ops, s,
+                          "arm-sysctl", 0x1000);
     sysbus_init_mmio(sd, &s->iomem);
     qdev_init_gpio_in(dev, arm_sysctl_gpio_set, 2);
     qdev_init_gpio_out(dev, &s->pl110_mux_ctrl, 1);
diff --git a/hw/misc/debugexit.c b/hw/misc/debugexit.c
index e3a13f045c..d754cf1f2e 100644
--- a/hw/misc/debugexit.c
+++ b/hw/misc/debugexit.c
@@ -40,7 +40,7 @@ static void debug_exit_realizefn(DeviceState *d, Error **errp)
     ISADevice *dev = ISA_DEVICE(d);
     ISADebugExitState *isa = ISA_DEBUG_EXIT_DEVICE(d);
 
-    memory_region_init_io(&isa->io, NULL, &debug_exit_ops, isa,
+    memory_region_init_io(&isa->io, OBJECT(dev), &debug_exit_ops, isa,
                           TYPE_ISA_DEBUG_EXIT_DEVICE, isa->iosize);
     memory_region_add_subregion(isa_address_space_io(dev),
                                 isa->iobase, &isa->io);
diff --git a/hw/misc/eccmemctl.c b/hw/misc/eccmemctl.c
index 71d62cc239..3de9675f64 100644
--- a/hw/misc/eccmemctl.c
+++ b/hw/misc/eccmemctl.c
@@ -296,11 +296,11 @@ static int ecc_init1(SysBusDevice *dev)
 
     sysbus_init_irq(dev, &s->irq);
     s->regs[0] = s->version;
-    memory_region_init_io(&s->iomem, NULL, &ecc_mem_ops, s, "ecc", ECC_SIZE);
+    memory_region_init_io(&s->iomem, OBJECT(dev), &ecc_mem_ops, s, "ecc", ECC_SIZE);
     sysbus_init_mmio(dev, &s->iomem);
 
     if (s->version == ECC_MCC) { // SS-600MP only
-        memory_region_init_io(&s->iomem_diag, NULL, &ecc_diag_mem_ops, s,
+        memory_region_init_io(&s->iomem_diag, OBJECT(dev), &ecc_diag_mem_ops, s,
                               "ecc.diag", ECC_DIAG_SIZE);
         sysbus_init_mmio(dev, &s->iomem_diag);
     }
diff --git a/hw/misc/exynos4210_pmu.c b/hw/misc/exynos4210_pmu.c
index 465e72f933..28395bae4b 100644
--- a/hw/misc/exynos4210_pmu.c
+++ b/hw/misc/exynos4210_pmu.c
@@ -458,8 +458,8 @@ static int exynos4210_pmu_init(SysBusDevice *dev)
     Exynos4210PmuState *s = FROM_SYSBUS(Exynos4210PmuState, dev);
 
     /* memory mapping */
-    memory_region_init_io(&s->iomem, NULL, &exynos4210_pmu_ops, s, "exynos4210.pmu",
-                          EXYNOS4210_PMU_REGS_MEM_SIZE);
+    memory_region_init_io(&s->iomem, OBJECT(dev), &exynos4210_pmu_ops, s,
+                          "exynos4210.pmu", EXYNOS4210_PMU_REGS_MEM_SIZE);
     sysbus_init_mmio(dev, &s->iomem);
     return 0;
 }
diff --git a/hw/misc/imx_ccm.c b/hw/misc/imx_ccm.c
index 863c219e7c..816d5e8331 100644
--- a/hw/misc/imx_ccm.c
+++ b/hw/misc/imx_ccm.c
@@ -281,7 +281,8 @@ static int imx_ccm_init(SysBusDevice *dev)
 {
     IMXCCMState *s = FROM_SYSBUS(typeof(*s), dev);
 
-    memory_region_init_io(&s->iomem, NULL, &imx_ccm_ops, s, "imx_ccm", 0x1000);
+    memory_region_init_io(&s->iomem, OBJECT(dev), &imx_ccm_ops, s,
+                          "imx_ccm", 0x1000);
     sysbus_init_mmio(dev, &s->iomem);
 
     return 0;
diff --git a/hw/misc/ivshmem.c b/hw/misc/ivshmem.c
index 522740d5bb..3594b84259 100644
--- a/hw/misc/ivshmem.c
+++ b/hw/misc/ivshmem.c
@@ -339,7 +339,7 @@ static void create_shared_memory_BAR(IVShmemState *s, int fd) {
 
     ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED, fd, 0);
 
-    memory_region_init_ram_ptr(&s->ivshmem, NULL, "ivshmem.bar2",
+    memory_region_init_ram_ptr(&s->ivshmem, OBJECT(s), "ivshmem.bar2",
                                s->ivshmem_size, ptr);
     vmstate_register_ram(&s->ivshmem, &s->dev.qdev);
     memory_region_add_subregion(&s->bar, 0, &s->ivshmem);
@@ -467,7 +467,7 @@ static void ivshmem_read(void *opaque, const uint8_t * buf, int flags)
         /* mmap the region and map into the BAR2 */
         map_ptr = mmap(0, s->ivshmem_size, PROT_READ|PROT_WRITE, MAP_SHARED,
                                                             incoming_fd, 0);
-        memory_region_init_ram_ptr(&s->ivshmem, NULL,
+        memory_region_init_ram_ptr(&s->ivshmem, OBJECT(s),
                                    "ivshmem.bar2", s->ivshmem_size, map_ptr);
         vmstate_register_ram(&s->ivshmem, &s->dev.qdev);
 
@@ -685,14 +685,14 @@ static int pci_ivshmem_init(PCIDevice *dev)
 
     s->shm_fd = 0;
 
-    memory_region_init_io(&s->ivshmem_mmio, NULL, &ivshmem_mmio_ops, s,
+    memory_region_init_io(&s->ivshmem_mmio, OBJECT(s), &ivshmem_mmio_ops, s,
                           "ivshmem-mmio", IVSHMEM_REG_BAR_SIZE);
 
     /* region for registers*/
     pci_register_bar(&s->dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY,
                      &s->ivshmem_mmio);
 
-    memory_region_init(&s->bar, NULL, "ivshmem-bar2-container", s->ivshmem_size);
+    memory_region_init(&s->bar, OBJECT(s), "ivshmem-bar2-container", s->ivshmem_size);
     s->ivshmem_attr = PCI_BASE_ADDRESS_SPACE_MEMORY |
         PCI_BASE_ADDRESS_MEM_PREFETCH;
     if (s->ivshmem_64bit) {
diff --git a/hw/misc/lm32_sys.c b/hw/misc/lm32_sys.c
index accfbe3c44..060a5bf9b3 100644
--- a/hw/misc/lm32_sys.c
+++ b/hw/misc/lm32_sys.c
@@ -117,7 +117,8 @@ static int lm32_sys_init(SysBusDevice *dev)
 {
     LM32SysState *s = FROM_SYSBUS(typeof(*s), dev);
 
-    memory_region_init_io(&s->iomem, NULL, &sys_ops , s, "sys", R_MAX * 4);
+    memory_region_init_io(&s->iomem, OBJECT(dev), &sys_ops , s,
+                          "sys", R_MAX * 4);
     sysbus_init_mmio(dev, &s->iomem);
 
     /* Note: This device is not created in the board initialization,
diff --git a/hw/misc/milkymist-hpdmc.c b/hw/misc/milkymist-hpdmc.c
index f4826b94bb..a498881190 100644
--- a/hw/misc/milkymist-hpdmc.c
+++ b/hw/misc/milkymist-hpdmc.c
@@ -127,7 +127,7 @@ static int milkymist_hpdmc_init(SysBusDevice *dev)
 {
     MilkymistHpdmcState *s = FROM_SYSBUS(typeof(*s), dev);
 
-    memory_region_init_io(&s->regs_region, NULL, &hpdmc_mmio_ops, s,
+    memory_region_init_io(&s->regs_region, OBJECT(dev), &hpdmc_mmio_ops, s,
             "milkymist-hpdmc", R_MAX * 4);
     sysbus_init_mmio(dev, &s->regs_region);
 
diff --git a/hw/misc/milkymist-pfpu.c b/hw/misc/milkymist-pfpu.c
index 0051bc955b..2b64ee77d8 100644
--- a/hw/misc/milkymist-pfpu.c
+++ b/hw/misc/milkymist-pfpu.c
@@ -497,7 +497,7 @@ static int milkymist_pfpu_init(SysBusDevice *dev)
 
     sysbus_init_irq(dev, &s->irq);
 
-    memory_region_init_io(&s->regs_region, NULL, &pfpu_mmio_ops, s,
+    memory_region_init_io(&s->regs_region, OBJECT(dev), &pfpu_mmio_ops, s,
             "milkymist-pfpu", MICROCODE_END * 4);
     sysbus_init_mmio(dev, &s->regs_region);
 
diff --git a/hw/misc/mst_fpga.c b/hw/misc/mst_fpga.c
index b727dabfbf..604be5eafe 100644
--- a/hw/misc/mst_fpga.c
+++ b/hw/misc/mst_fpga.c
@@ -208,7 +208,7 @@ static int mst_fpga_init(SysBusDevice *dev)
 	/* alloc the external 16 irqs */
 	qdev_init_gpio_in(&dev->qdev, mst_fpga_set_irq, MST_NUM_IRQS);
 
-	memory_region_init_io(&s->iomem, NULL, &mst_fpga_ops, s,
+	memory_region_init_io(&s->iomem, OBJECT(s), &mst_fpga_ops, s,
 			    "fpga", 0x00100000);
 	sysbus_init_mmio(dev, &s->iomem);
 	return 0;
diff --git a/hw/misc/pc-testdev.c b/hw/misc/pc-testdev.c
index 31c9878649..699a16ffbe 100644
--- a/hw/misc/pc-testdev.c
+++ b/hw/misc/pc-testdev.c
@@ -149,13 +149,13 @@ static void testdev_realizefn(DeviceState *d, Error **errp)
     MemoryRegion *mem = isa_address_space(isa);
     MemoryRegion *io = isa_address_space_io(isa);
 
-    memory_region_init_io(&dev->ioport, NULL, &test_ioport_ops, dev,
+    memory_region_init_io(&dev->ioport, OBJECT(dev), &test_ioport_ops, dev,
                           "pc-testdev-ioport", 4);
-    memory_region_init_io(&dev->flush, NULL, &test_flush_ops, dev,
+    memory_region_init_io(&dev->flush, OBJECT(dev), &test_flush_ops, dev,
                           "pc-testdev-flush-page", 4);
-    memory_region_init_io(&dev->irq, NULL, &test_irq_ops, dev,
+    memory_region_init_io(&dev->irq, OBJECT(dev), &test_irq_ops, dev,
                           "pc-testdev-irq-line", 24);
-    memory_region_init_io(&dev->iomem, NULL, &test_iomem_ops, dev,
+    memory_region_init_io(&dev->iomem, OBJECT(dev), &test_iomem_ops, dev,
                           "pc-testdev-iomem", IOMEM_LEN);
 
     memory_region_add_subregion(io,  0xe0,       &dev->ioport);
diff --git a/hw/misc/pci-testdev.c b/hw/misc/pci-testdev.c
index fb9a58c5a3..8b0b73f9c4 100644
--- a/hw/misc/pci-testdev.c
+++ b/hw/misc/pci-testdev.c
@@ -236,9 +236,9 @@ static int pci_testdev_init(PCIDevice *pci_dev)
 
     pci_conf[PCI_INTERRUPT_PIN] = 0; /* no interrupt pin */
 
-    memory_region_init_io(&d->mmio, NULL, &pci_testdev_mmio_ops, d,
+    memory_region_init_io(&d->mmio, OBJECT(d), &pci_testdev_mmio_ops, d,
                           "pci-testdev-mmio", IOTEST_MEMSIZE * 2);
-    memory_region_init_io(&d->portio, NULL, &pci_testdev_pio_ops, d,
+    memory_region_init_io(&d->portio, OBJECT(d), &pci_testdev_pio_ops, d,
                           "pci-testdev-portio", IOTEST_IOSIZE * 2);
     pci_register_bar(&d->dev, 0, PCI_BASE_ADDRESS_SPACE_MEMORY, &d->mmio);
     pci_register_bar(&d->dev, 1, PCI_BASE_ADDRESS_SPACE_IO, &d->portio);
diff --git a/hw/misc/puv3_pm.c b/hw/misc/puv3_pm.c
index d4a863f0c9..5592560014 100644
--- a/hw/misc/puv3_pm.c
+++ b/hw/misc/puv3_pm.c
@@ -120,7 +120,7 @@ static int puv3_pm_init(SysBusDevice *dev)
 
     s->reg_PCGR = 0x0;
 
-    memory_region_init_io(&s->iomem, NULL, &puv3_pm_ops, s, "puv3_pm",
+    memory_region_init_io(&s->iomem, OBJECT(s), &puv3_pm_ops, s, "puv3_pm",
             PUV3_REGS_OFFSET);
     sysbus_init_mmio(dev, &s->iomem);
 
diff --git a/hw/misc/pvpanic.c b/hw/misc/pvpanic.c
index 00d6e6343f..a3be9e0c87 100644
--- a/hw/misc/pvpanic.c
+++ b/hw/misc/pvpanic.c
@@ -90,7 +90,7 @@ static void pvpanic_isa_initfn(Object *obj)
 {
     PVPanicState *s = ISA_PVPANIC_DEVICE(obj);
 
-    memory_region_init_io(&s->io, NULL, &pvpanic_ops, s, "pvpanic", 1);
+    memory_region_init_io(&s->io, OBJECT(s), &pvpanic_ops, s, "pvpanic", 1);
 }
 
 static void pvpanic_isa_realizefn(DeviceState *dev, Error **errp)
diff --git a/hw/misc/slavio_misc.c b/hw/misc/slavio_misc.c
index dbc6081b1d..d274fb4a87 100644
--- a/hw/misc/slavio_misc.c
+++ b/hw/misc/slavio_misc.c
@@ -412,7 +412,7 @@ static int apc_init1(SysBusDevice *dev)
     sysbus_init_irq(dev, &s->cpu_halt);
 
     /* Power management (APC) XXX: not a Slavio device */
-    memory_region_init_io(&s->iomem, NULL, &apc_mem_ops, s,
+    memory_region_init_io(&s->iomem, OBJECT(s), &apc_mem_ops, s,
                           "apc", MISC_SIZE);
     sysbus_init_mmio(dev, &s->iomem);
     return 0;
@@ -427,39 +427,39 @@ static int slavio_misc_init1(SysBusDevice *dev)
 
     /* 8 bit registers */
     /* Slavio control */
-    memory_region_init_io(&s->cfg_iomem, NULL, &slavio_cfg_mem_ops, s,
+    memory_region_init_io(&s->cfg_iomem, OBJECT(s), &slavio_cfg_mem_ops, s,
                           "configuration", MISC_SIZE);
     sysbus_init_mmio(dev, &s->cfg_iomem);
 
     /* Diagnostics */
-    memory_region_init_io(&s->diag_iomem, NULL, &slavio_diag_mem_ops, s,
+    memory_region_init_io(&s->diag_iomem, OBJECT(s), &slavio_diag_mem_ops, s,
                           "diagnostic", MISC_SIZE);
     sysbus_init_mmio(dev, &s->diag_iomem);
 
     /* Modem control */
-    memory_region_init_io(&s->mdm_iomem, NULL, &slavio_mdm_mem_ops, s,
+    memory_region_init_io(&s->mdm_iomem, OBJECT(s), &slavio_mdm_mem_ops, s,
                           "modem", MISC_SIZE);
     sysbus_init_mmio(dev, &s->mdm_iomem);
 
     /* 16 bit registers */
     /* ss600mp diag LEDs */
-    memory_region_init_io(&s->led_iomem, NULL, &slavio_led_mem_ops, s,
+    memory_region_init_io(&s->led_iomem, OBJECT(s), &slavio_led_mem_ops, s,
                           "leds", MISC_SIZE);
     sysbus_init_mmio(dev, &s->led_iomem);
 
     /* 32 bit registers */
     /* System control */
-    memory_region_init_io(&s->sysctrl_iomem, NULL, &slavio_sysctrl_mem_ops, s,
+    memory_region_init_io(&s->sysctrl_iomem, OBJECT(s), &slavio_sysctrl_mem_ops, s,
                           "system-control", MISC_SIZE);
     sysbus_init_mmio(dev, &s->sysctrl_iomem);
 
     /* AUX 1 (Misc System Functions) */
-    memory_region_init_io(&s->aux1_iomem, NULL, &slavio_aux1_mem_ops, s,
+    memory_region_init_io(&s->aux1_iomem, OBJECT(s), &slavio_aux1_mem_ops, s,
                           "misc-system-functions", MISC_SIZE);
     sysbus_init_mmio(dev, &s->aux1_iomem);
 
     /* AUX 2 (Software Powerdown Control) */
-    memory_region_init_io(&s->aux2_iomem, NULL, &slavio_aux2_mem_ops, s,
+    memory_region_init_io(&s->aux2_iomem, OBJECT(s), &slavio_aux2_mem_ops, s,
                           "software-powerdown-control", MISC_SIZE);
     sysbus_init_mmio(dev, &s->aux2_iomem);
 
diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c
index 58013ebbf3..540c377f61 100644
--- a/hw/misc/vfio.c
+++ b/hw/misc/vfio.c
@@ -1154,7 +1154,7 @@ static void vfio_vga_probe_ati_3c3_quirk(VFIODevice *vdev)
     quirk->vdev = vdev;
     quirk->data = (physbar >> 8) & 0xff;
 
-    memory_region_init_io(&quirk->mem, NULL, &vfio_ati_3c3_quirk, quirk,
+    memory_region_init_io(&quirk->mem, OBJECT(vdev), &vfio_ati_3c3_quirk, quirk,
                           "vfio-ati-3c3-quirk", 1);
     memory_region_add_subregion(&vdev->vga.region[QEMU_PCI_VGA_IO_HI].mem, 3,
                                 &quirk->mem);
@@ -1245,7 +1245,7 @@ static void vfio_probe_ati_4010_quirk(VFIODevice *vdev, int nr)
     quirk = g_malloc0(sizeof(*quirk));
     quirk->vdev = vdev;
 
-    memory_region_init_io(&quirk->mem, NULL, &vfio_ati_4010_quirk, quirk,
+    memory_region_init_io(&quirk->mem, OBJECT(vdev), &vfio_ati_4010_quirk, quirk,
                           "vfio-ati-4010-quirk", 8);
     memory_region_add_subregion_overlap(&vdev->bars[nr].mem, 0, &quirk->mem, 1);
 
@@ -1331,7 +1331,7 @@ static void vfio_probe_ati_f10_quirk(VFIODevice *vdev, int nr)
     quirk = g_malloc0(sizeof(*quirk));
     quirk->vdev = vdev;
 
-    memory_region_init_io(&quirk->mem, NULL, &vfio_ati_f10_quirk, quirk,
+    memory_region_init_io(&quirk->mem, OBJECT(vdev), &vfio_ati_f10_quirk, quirk,
                           "vfio-ati-f10-quirk", 8);
     memory_region_add_subregion_overlap(&vdev->bars[nr].mem, 0, &quirk->mem, 1);
 
@@ -1451,7 +1451,7 @@ static void vfio_vga_probe_nvidia_3d0_quirk(VFIODevice *vdev)
     quirk = g_malloc0(sizeof(*quirk));
     quirk->vdev = vdev;
 
-    memory_region_init_io(&quirk->mem, NULL, &vfio_nvidia_3d0_quirk, quirk,
+    memory_region_init_io(&quirk->mem, OBJECT(vdev), &vfio_nvidia_3d0_quirk, quirk,
                           "vfio-nvidia-3d0-quirk", 6);
     memory_region_add_subregion(&vdev->vga.region[QEMU_PCI_VGA_IO_HI].mem,
                                 0x10, &quirk->mem);
@@ -1566,7 +1566,7 @@ static void vfio_probe_nvidia_bar5_window_quirk(VFIODevice *vdev, int nr)
     quirk = g_malloc0(sizeof(*quirk));
     quirk->vdev = vdev;
 
-    memory_region_init_io(&quirk->mem, NULL, &vfio_nvidia_bar5_window_quirk, quirk,
+    memory_region_init_io(&quirk->mem, OBJECT(vdev), &vfio_nvidia_bar5_window_quirk, quirk,
                           "vfio-nvidia-bar5-window-quirk", 16);
     memory_region_add_subregion_overlap(&vdev->bars[nr].mem, 0, &quirk->mem, 1);
 
@@ -1644,7 +1644,7 @@ static void vfio_probe_nvidia_bar0_88000_quirk(VFIODevice *vdev, int nr)
     quirk = g_malloc0(sizeof(*quirk));
     quirk->vdev = vdev;
 
-    memory_region_init_io(&quirk->mem, NULL, &vfio_nvidia_bar0_88000_quirk, quirk,
+    memory_region_init_io(&quirk->mem, OBJECT(vdev), &vfio_nvidia_bar0_88000_quirk, quirk,
                           "vfio-nvidia-bar0-88000-quirk",
                           TARGET_PAGE_ALIGN(PCIE_CONFIG_SPACE_SIZE));
     memory_region_add_subregion_overlap(&vdev->bars[nr].mem,
@@ -1723,7 +1723,7 @@ static void vfio_probe_nvidia_bar0_1800_quirk(VFIODevice *vdev, int nr)
     quirk = g_malloc0(sizeof(*quirk));
     quirk->vdev = vdev;
 
-    memory_region_init_io(&quirk->mem, NULL, &vfio_nvidia_bar0_1800_quirk, quirk,
+    memory_region_init_io(&quirk->mem, OBJECT(vdev), &vfio_nvidia_bar0_1800_quirk, quirk,
                           "vfio-nvidia-bar0-1800-quirk",
                           TARGET_PAGE_ALIGN(PCI_CONFIG_SPACE_SIZE));
     memory_region_add_subregion_overlap(&vdev->bars[nr].mem,
@@ -2274,7 +2274,7 @@ static void vfio_map_bar(VFIODevice *vdev, int nr)
            ~PCI_BASE_ADDRESS_IO_MASK : ~PCI_BASE_ADDRESS_MEM_MASK);
 
     /* A "slow" read/write mapping underlies all BARs */
-    memory_region_init_io(&bar->mem, NULL, &vfio_bar_ops, bar, name, size);
+    memory_region_init_io(&bar->mem, OBJECT(vdev), &vfio_bar_ops, bar, name, size);
     pci_register_bar(&vdev->pdev, nr, type, &bar->mem);
 
     /*
@@ -2318,18 +2318,18 @@ static void vfio_map_bars(VFIODevice *vdev)
     }
 
     if (vdev->has_vga) {
-        memory_region_init_io(&vdev->vga.region[QEMU_PCI_VGA_MEM].mem, NULL,
-                              &vfio_vga_ops,
+        memory_region_init_io(&vdev->vga.region[QEMU_PCI_VGA_MEM].mem,
+                              OBJECT(vdev), &vfio_vga_ops,
                               &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, NULL,
-                              &vfio_vga_ops,
+        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],
                               "vfio-vga-io@0x3b0",
                               QEMU_PCI_VGA_IO_LO_SIZE);
-        memory_region_init_io(&vdev->vga.region[QEMU_PCI_VGA_IO_HI].mem, NULL,
-                              &vfio_vga_ops,
+        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],
                               "vfio-vga-io@0x3c0",
                               QEMU_PCI_VGA_IO_HI_SIZE);
@@ -2591,7 +2591,7 @@ static int vfio_load_rom(VFIODevice *vdev)
     snprintf(name, sizeof(name), "vfio[%04x:%02x:%02x.%x].rom",
              vdev->host.domain, vdev->host.bus, vdev->host.slot,
              vdev->host.function);
-    memory_region_init_ram(&vdev->pdev.rom, NULL, name, size);
+    memory_region_init_ram(&vdev->pdev.rom, OBJECT(vdev), name, size);
     ptr = memory_region_get_ram_ptr(&vdev->pdev.rom);
     memset(ptr, 0xff, size);
 
diff --git a/hw/misc/vmport.c b/hw/misc/vmport.c
index 7f64ccda62..7463776784 100644
--- a/hw/misc/vmport.c
+++ b/hw/misc/vmport.c
@@ -142,7 +142,7 @@ static void vmport_realizefn(DeviceState *dev, Error **errp)
     ISADevice *isadev = ISA_DEVICE(dev);
     VMPortState *s = VMPORT(dev);
 
-    memory_region_init_io(&s->io, NULL, &vmport_ops, s, "vmport", 1);
+    memory_region_init_io(&s->io, OBJECT(s), &vmport_ops, s, "vmport", 1);
     isa_register_ioport(isadev, &s->io, 0x5658);
 
     port_state = s;
diff --git a/hw/misc/zynq_slcr.c b/hw/misc/zynq_slcr.c
index d7c2d190ec..fc7a85f0dd 100644
--- a/hw/misc/zynq_slcr.c
+++ b/hw/misc/zynq_slcr.c
@@ -494,7 +494,7 @@ static int zynq_slcr_init(SysBusDevice *dev)
 {
     ZynqSLCRState *s = FROM_SYSBUS(ZynqSLCRState, dev);
 
-    memory_region_init_io(&s->iomem, NULL, &slcr_ops, s, "slcr", 0x1000);
+    memory_region_init_io(&s->iomem, OBJECT(s), &slcr_ops, s, "slcr", 0x1000);
     sysbus_init_mmio(dev, &s->iomem);
 
     return 0;