diff --git a/hw/acpi.c b/hw/acpi.c
index f4aca493fc..ae29a59077 100644
--- a/hw/acpi.c
+++ b/hw/acpi.c
@@ -275,7 +275,7 @@ uint16_t acpi_pm1_evt_get_sts(ACPIREGS *ar)
     return ar->pm1.evt.sts;
 }
 
-void acpi_pm1_evt_write_sts(ACPIREGS *ar, uint16_t val)
+static void acpi_pm1_evt_write_sts(ACPIREGS *ar, uint16_t val)
 {
     uint16_t pm1_sts = acpi_pm1_evt_get_sts(ar);
     if (pm1_sts & val & ACPI_BITMASK_TIMER_STATUS) {
@@ -285,7 +285,7 @@ void acpi_pm1_evt_write_sts(ACPIREGS *ar, uint16_t val)
     ar->pm1.evt.sts &= ~val;
 }
 
-void acpi_pm1_evt_write_en(ACPIREGS *ar, uint16_t val)
+static void acpi_pm1_evt_write_en(ACPIREGS *ar, uint16_t val)
 {
     ar->pm1.evt.en = val;
     qemu_system_wakeup_enable(QEMU_WAKEUP_REASON_RTC,
@@ -310,6 +310,51 @@ void acpi_pm1_evt_reset(ACPIREGS *ar)
     qemu_system_wakeup_enable(QEMU_WAKEUP_REASON_PMTIMER, 0);
 }
 
+static uint64_t acpi_pm_evt_read(void *opaque, hwaddr addr, unsigned width)
+{
+    ACPIREGS *ar = opaque;
+    switch (addr) {
+    case 0:
+        return acpi_pm1_evt_get_sts(ar);
+    case 2:
+        return ar->pm1.evt.en;
+    default:
+        return 0;
+    }
+}
+
+static void acpi_pm_evt_write(void *opaque, hwaddr addr, uint64_t val,
+                              unsigned width)
+{
+    ACPIREGS *ar = opaque;
+    switch (addr) {
+    case 0:
+        acpi_pm1_evt_write_sts(ar, val);
+        ar->pm1.evt.update_sci(ar);
+        break;
+    case 2:
+        acpi_pm1_evt_write_en(ar, val);
+        ar->pm1.evt.update_sci(ar);
+        break;
+    }
+}
+
+static const MemoryRegionOps acpi_pm_evt_ops = {
+    .read = acpi_pm_evt_read,
+    .write = acpi_pm_evt_write,
+    .valid.min_access_size = 2,
+    .valid.max_access_size = 2,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+void acpi_pm1_evt_init(ACPIREGS *ar, acpi_update_sci_fn update_sci,
+                       MemoryRegion *parent)
+{
+    ar->pm1.evt.update_sci = update_sci;
+    memory_region_init_io(&ar->pm1.evt.io, &acpi_pm_evt_ops, ar, "acpi-evt", 4);
+    memory_region_add_subregion(parent, 0, &ar->pm1.evt.io);
+}
+
 /* ACPI PM_TMR */
 void acpi_pm_tmr_update(ACPIREGS *ar, bool enable)
 {
@@ -331,7 +376,7 @@ void acpi_pm_tmr_calc_overflow_time(ACPIREGS *ar)
     ar->tmr.overflow_time = (d + 0x800000LL) & ~0x7fffffLL;
 }
 
-uint32_t acpi_pm_tmr_get(ACPIREGS *ar)
+static uint32_t acpi_pm_tmr_get(ACPIREGS *ar)
 {
     uint32_t d = acpi_pm_tmr_get_clock();
     return d & 0xffffff;
@@ -344,10 +389,25 @@ static void acpi_pm_tmr_timer(void *opaque)
     ar->tmr.update_sci(ar);
 }
 
-void acpi_pm_tmr_init(ACPIREGS *ar, acpi_update_sci_fn update_sci)
+static uint64_t acpi_pm_tmr_read(void *opaque, hwaddr addr, unsigned width)
+{
+    return acpi_pm_tmr_get(opaque);
+}
+
+static const MemoryRegionOps acpi_pm_tmr_ops = {
+    .read = acpi_pm_tmr_read,
+    .valid.min_access_size = 4,
+    .valid.max_access_size = 4,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+void acpi_pm_tmr_init(ACPIREGS *ar, acpi_update_sci_fn update_sci,
+                      MemoryRegion *parent)
 {
     ar->tmr.update_sci = update_sci;
     ar->tmr.timer = qemu_new_timer_ns(vm_clock, acpi_pm_tmr_timer, ar);
+    memory_region_init_io(&ar->tmr.io, &acpi_pm_tmr_ops, ar, "acpi-tmr", 4);
+    memory_region_add_subregion(parent, 8, &ar->tmr.io);
 }
 
 void acpi_pm_tmr_reset(ACPIREGS *ar)
@@ -357,13 +417,7 @@ void acpi_pm_tmr_reset(ACPIREGS *ar)
 }
 
 /* ACPI PM1aCNT */
-void acpi_pm1_cnt_init(ACPIREGS *ar)
-{
-    ar->wakeup.notify = acpi_notify_wakeup;
-    qemu_register_wakeup_notifier(&ar->wakeup);
-}
-
-void acpi_pm1_cnt_write(ACPIREGS *ar, uint16_t val, char s4)
+static void acpi_pm1_cnt_write(ACPIREGS *ar, uint16_t val)
 {
     ar->pm1.cnt.cnt = val & ~(ACPI_BITMASK_SLEEP_ENABLE);
 
@@ -378,7 +432,7 @@ void acpi_pm1_cnt_write(ACPIREGS *ar, uint16_t val, char s4)
             qemu_system_suspend_request();
             break;
         default:
-            if (sus_typ == s4) { /* S4 request */
+            if (sus_typ == ar->pm1.cnt.s4_val) { /* S4 request */
                 monitor_protocol_event(QEVENT_SUSPEND_DISK, NULL);
                 qemu_system_shutdown_request();
             }
@@ -398,6 +452,34 @@ void acpi_pm1_cnt_update(ACPIREGS *ar,
     }
 }
 
+static uint64_t acpi_pm_cnt_read(void *opaque, hwaddr addr, unsigned width)
+{
+    ACPIREGS *ar = opaque;
+    return ar->pm1.cnt.cnt;
+}
+
+static void acpi_pm_cnt_write(void *opaque, hwaddr addr, uint64_t val,
+                              unsigned width)
+{
+    acpi_pm1_cnt_write(opaque, val);
+}
+
+static const MemoryRegionOps acpi_pm_cnt_ops = {
+    .read = acpi_pm_cnt_read,
+    .write = acpi_pm_cnt_write,
+    .valid.min_access_size = 2,
+    .valid.max_access_size = 2,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+void acpi_pm1_cnt_init(ACPIREGS *ar, MemoryRegion *parent)
+{
+    ar->wakeup.notify = acpi_notify_wakeup;
+    qemu_register_wakeup_notifier(&ar->wakeup);
+    memory_region_init_io(&ar->pm1.cnt.io, &acpi_pm_cnt_ops, ar, "acpi-cnt", 2);
+    memory_region_add_subregion(parent, 4, &ar->pm1.cnt.io);
+}
+
 void acpi_pm1_cnt_reset(ACPIREGS *ar)
 {
     ar->pm1.cnt.cnt = 0;
@@ -411,11 +493,6 @@ void acpi_gpe_init(ACPIREGS *ar, uint8_t len)
     ar->gpe.en = g_malloc0(len / 2);
 }
 
-void acpi_gpe_blk(ACPIREGS *ar, uint32_t blk)
-{
-    ar->gpe.blk = blk;
-}
-
 void acpi_gpe_reset(ACPIREGS *ar)
 {
     memset(ar->gpe.sts, 0, ar->gpe.len / 2);
@@ -441,7 +518,6 @@ void acpi_gpe_ioport_writeb(ACPIREGS *ar, uint32_t addr, uint32_t val)
 {
     uint8_t *cur;
 
-    addr -= ar->gpe.blk;
     cur = acpi_gpe_ioport_get_ptr(ar, addr);
     if (addr < ar->gpe.len / 2) {
         /* GPE_STS */
@@ -459,7 +535,6 @@ uint32_t acpi_gpe_ioport_readb(ACPIREGS *ar, uint32_t addr)
     uint8_t *cur;
     uint32_t val;
 
-    addr -= ar->gpe.blk;
     cur = acpi_gpe_ioport_get_ptr(ar, addr);
     val = 0;
     if (cur != NULL) {
diff --git a/hw/acpi.h b/hw/acpi.h
index 7337f41857..afda153d09 100644
--- a/hw/acpi.h
+++ b/hw/acpi.h
@@ -84,22 +84,26 @@ typedef void (*acpi_update_sci_fn)(ACPIREGS *ar);
 
 struct ACPIPMTimer {
     QEMUTimer *timer;
+    MemoryRegion io;
     int64_t overflow_time;
 
     acpi_update_sci_fn update_sci;
 };
 
 struct ACPIPM1EVT {
+    MemoryRegion io;
     uint16_t sts;
     uint16_t en;
+    acpi_update_sci_fn update_sci;
 };
 
 struct ACPIPM1CNT {
+    MemoryRegion io;
     uint16_t cnt;
+    uint8_t s4_val;
 };
 
 struct ACPIGPE {
-    uint32_t blk;
     uint8_t len;
 
     uint8_t *sts;
@@ -119,8 +123,8 @@ struct ACPIREGS {
 /* PM_TMR */
 void acpi_pm_tmr_update(ACPIREGS *ar, bool enable);
 void acpi_pm_tmr_calc_overflow_time(ACPIREGS *ar);
-uint32_t acpi_pm_tmr_get(ACPIREGS *ar);
-void acpi_pm_tmr_init(ACPIREGS *ar, acpi_update_sci_fn update_sci);
+void acpi_pm_tmr_init(ACPIREGS *ar, acpi_update_sci_fn update_sci,
+                      MemoryRegion *parent);
 void acpi_pm_tmr_reset(ACPIREGS *ar);
 
 #include "qemu-timer.h"
@@ -132,21 +136,19 @@ static inline int64_t acpi_pm_tmr_get_clock(void)
 
 /* PM1a_EVT: piix and ich9 don't implement PM1b. */
 uint16_t acpi_pm1_evt_get_sts(ACPIREGS *ar);
-void acpi_pm1_evt_write_sts(ACPIREGS *ar, uint16_t val);
-void acpi_pm1_evt_write_en(ACPIREGS *ar, uint16_t val);
 void acpi_pm1_evt_power_down(ACPIREGS *ar);
 void acpi_pm1_evt_reset(ACPIREGS *ar);
+void acpi_pm1_evt_init(ACPIREGS *ar, acpi_update_sci_fn update_sci,
+                       MemoryRegion *parent);
 
 /* PM1a_CNT: piix and ich9 don't implement PM1b CNT. */
-void acpi_pm1_cnt_init(ACPIREGS *ar);
-void acpi_pm1_cnt_write(ACPIREGS *ar, uint16_t val, char s4);
+void acpi_pm1_cnt_init(ACPIREGS *ar, MemoryRegion *parent);
 void acpi_pm1_cnt_update(ACPIREGS *ar,
                          bool sci_enable, bool sci_disable);
 void acpi_pm1_cnt_reset(ACPIREGS *ar);
 
 /* GPE0 */
 void acpi_gpe_init(ACPIREGS *ar, uint8_t len);
-void acpi_gpe_blk(ACPIREGS *ar, uint32_t blk);
 void acpi_gpe_reset(ACPIREGS *ar);
 
 void acpi_gpe_ioport_writeb(ACPIREGS *ar, uint32_t addr, uint32_t val);
diff --git a/hw/acpi_ich9.c b/hw/acpi_ich9.c
index 61034d3bd7..c5978d33cc 100644
--- a/hw/acpi_ich9.c
+++ b/hw/acpi_ich9.c
@@ -29,6 +29,7 @@
 #include "sysemu.h"
 #include "acpi.h"
 #include "kvm.h"
+#include "exec-memory.h"
 
 #include "ich9.h"
 
@@ -41,10 +42,6 @@ do { printf("%s "fmt, __func__, ## __VA_ARGS__); } while (0)
 #define ICH9_DEBUG(fmt, ...)    do { } while (0)
 #endif
 
-static void pm_ioport_write_fallback(void *opaque, uint32_t addr, int len,
-                                     uint32_t val);
-static uint32_t pm_ioport_read_fallback(void *opaque, uint32_t addr, int len);
-
 static void pm_update_sci(ICH9LPCPMRegs *pm)
 {
     int sci_level, pm1a_sts;
@@ -70,152 +67,60 @@ static void ich9_pm_update_sci_fn(ACPIREGS *regs)
     pm_update_sci(pm);
 }
 
-static void pm_ioport_writeb(void *opaque, uint32_t addr, uint32_t val)
+static uint64_t ich9_gpe_readb(void *opaque, hwaddr addr, unsigned width)
 {
     ICH9LPCPMRegs *pm = opaque;
-
-    switch (addr & ICH9_PMIO_MASK) {
-    case ICH9_PMIO_GPE0_STS ... (ICH9_PMIO_GPE0_STS + ICH9_PMIO_GPE0_LEN - 1):
-        acpi_gpe_ioport_writeb(&pm->acpi_regs, addr, val);
-        break;
-    default:
-        break;
-    }
-
-    ICH9_DEBUG("port=0x%04x val=0x%04x\n", addr, val);
+    return acpi_gpe_ioport_readb(&pm->acpi_regs, addr);
 }
 
-static uint32_t pm_ioport_readb(void *opaque, uint32_t addr)
+static void ich9_gpe_writeb(void *opaque, hwaddr addr, uint64_t val,
+                            unsigned width)
 {
     ICH9LPCPMRegs *pm = opaque;
-    uint32_t val = 0;
-
-    switch (addr & ICH9_PMIO_MASK) {
-    case ICH9_PMIO_GPE0_STS ... (ICH9_PMIO_GPE0_STS + ICH9_PMIO_GPE0_LEN - 1):
-        val = acpi_gpe_ioport_readb(&pm->acpi_regs, addr);
-        break;
-    default:
-        val = 0;
-        break;
-    }
-    ICH9_DEBUG("port=0x%04x val=0x%04x\n", addr, val);
-    return val;
+    acpi_gpe_ioport_writeb(&pm->acpi_regs, addr, val);
 }
 
-static void pm_ioport_writew(void *opaque, uint32_t addr, uint32_t val)
+static const MemoryRegionOps ich9_gpe_ops = {
+    .read = ich9_gpe_readb,
+    .write = ich9_gpe_writeb,
+    .valid.min_access_size = 1,
+    .valid.max_access_size = 4,
+    .impl.min_access_size = 1,
+    .impl.max_access_size = 1,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
+static uint64_t ich9_smi_readl(void *opaque, hwaddr addr, unsigned width)
 {
     ICH9LPCPMRegs *pm = opaque;
-
-    switch (addr & ICH9_PMIO_MASK) {
-    case ICH9_PMIO_PM1_STS:
-        acpi_pm1_evt_write_sts(&pm->acpi_regs, val);
-        pm_update_sci(pm);
-        break;
-    case ICH9_PMIO_PM1_EN:
-        pm->acpi_regs.pm1.evt.en = val;
-        pm_update_sci(pm);
-        break;
-    case ICH9_PMIO_PM1_CNT:
-        acpi_pm1_cnt_write(&pm->acpi_regs, val, 0);
-        break;
+    switch (addr) {
+    case 0:
+        return pm->smi_en;
+    case 4:
+        return pm->smi_sts;
     default:
-        pm_ioport_write_fallback(opaque, addr, 2, val);
-        break;
+        return 0;
     }
-    ICH9_DEBUG("port=0x%04x val=0x%04x\n", addr, val);
 }
 
-static uint32_t pm_ioport_readw(void *opaque, uint32_t addr)
+static void ich9_smi_writel(void *opaque, hwaddr addr, uint64_t val,
+                            unsigned width)
 {
     ICH9LPCPMRegs *pm = opaque;
-    uint32_t val;
-
-    switch (addr & ICH9_PMIO_MASK) {
-    case ICH9_PMIO_PM1_STS:
-        val = acpi_pm1_evt_get_sts(&pm->acpi_regs);
-        break;
-    case ICH9_PMIO_PM1_EN:
-        val = pm->acpi_regs.pm1.evt.en;
-        break;
-    case ICH9_PMIO_PM1_CNT:
-        val = pm->acpi_regs.pm1.cnt.cnt;
-        break;
-    default:
-        val = pm_ioport_read_fallback(opaque, addr, 2);
-        break;
-    }
-    ICH9_DEBUG("port=0x%04x val=0x%04x\n", addr, val);
-    return val;
-}
-
-static void pm_ioport_writel(void *opaque, uint32_t addr, uint32_t val)
-{
-    ICH9LPCPMRegs *pm = opaque;
-
-    switch (addr & ICH9_PMIO_MASK) {
-    case ICH9_PMIO_SMI_EN:
+    switch (addr) {
+    case 0:
         pm->smi_en = val;
         break;
-    default:
-        pm_ioport_write_fallback(opaque, addr, 4, val);
-        break;
-    }
-    ICH9_DEBUG("port=0x%04x val=0x%08x\n", addr, val);
-}
-
-static uint32_t pm_ioport_readl(void *opaque, uint32_t addr)
-{
-    ICH9LPCPMRegs *pm = opaque;
-    uint32_t val;
-
-    switch (addr & ICH9_PMIO_MASK) {
-    case ICH9_PMIO_PM1_TMR:
-        val = acpi_pm_tmr_get(&pm->acpi_regs);
-        break;
-    case ICH9_PMIO_SMI_EN:
-        val = pm->smi_en;
-        break;
-
-    default:
-        val = pm_ioport_read_fallback(opaque, addr, 4);
-        break;
-    }
-    ICH9_DEBUG("port=0x%04x val=0x%08x\n", addr, val);
-    return val;
-}
-
-static void pm_ioport_write_fallback(void *opaque, uint32_t addr, int len,
-                                     uint32_t val)
- {
-    int subsize = (len == 4) ? 2 : 1;
-    IOPortWriteFunc *ioport_write =
-        (subsize == 2) ? pm_ioport_writew : pm_ioport_writeb;
-
-    int i;
-
-    for (i = 0; i < len; i += subsize) {
-        ioport_write(opaque, addr, val);
-        val >>= 8 * subsize;
     }
 }
 
-static uint32_t pm_ioport_read_fallback(void *opaque, uint32_t addr, int len)
-{
-    int subsize = (len == 4) ? 2 : 1;
-    IOPortReadFunc *ioport_read =
-        (subsize == 2) ? pm_ioport_readw : pm_ioport_readb;
-
-    uint32_t val;
-    int i;
-
-    val = 0;
-    for (i = 0; i < len; i += subsize) {
-        val <<= 8 * subsize;
-        val |= ioport_read(opaque, addr);
-    }
-
-    return val;
-}
+static const MemoryRegionOps ich9_smi_ops = {
+    .read = ich9_smi_readl,
+    .write = ich9_smi_writel,
+    .valid.min_access_size = 4,
+    .valid.max_access_size = 4,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
 
 void ich9_pm_iospace_update(ICH9LPCPMRegs *pm, uint32_t pm_io_base)
 {
@@ -223,24 +128,11 @@ void ich9_pm_iospace_update(ICH9LPCPMRegs *pm, uint32_t pm_io_base)
 
     assert((pm_io_base & ICH9_PMIO_MASK) == 0);
 
-    if (pm->pm_io_base != 0) {
-        isa_unassign_ioport(pm->pm_io_base, ICH9_PMIO_SIZE);
-    }
-
-    /* don't map at 0 */
-    if (pm_io_base == 0) {
-        return;
-    }
-
-    register_ioport_write(pm_io_base, ICH9_PMIO_SIZE, 1, pm_ioport_writeb, pm);
-    register_ioport_read(pm_io_base, ICH9_PMIO_SIZE, 1, pm_ioport_readb, pm);
-    register_ioport_write(pm_io_base, ICH9_PMIO_SIZE, 2, pm_ioport_writew, pm);
-    register_ioport_read(pm_io_base, ICH9_PMIO_SIZE, 2, pm_ioport_readw, pm);
-    register_ioport_write(pm_io_base, ICH9_PMIO_SIZE, 4, pm_ioport_writel, pm);
-    register_ioport_read(pm_io_base, ICH9_PMIO_SIZE, 4, pm_ioport_readl, pm);
-
     pm->pm_io_base = pm_io_base;
-    acpi_gpe_blk(&pm->acpi_regs, pm_io_base + ICH9_PMIO_GPE0_STS);
+    memory_region_transaction_begin();
+    memory_region_set_enabled(&pm->io, pm->pm_io_base != 0);
+    memory_region_set_address(&pm->io, pm->pm_io_base);
+    memory_region_transaction_commit();
 }
 
 static int ich9_pm_post_load(void *opaque, int version_id)
@@ -311,9 +203,22 @@ static void pm_powerdown_req(Notifier *n, void *opaque)
 
 void ich9_pm_init(ICH9LPCPMRegs *pm, qemu_irq sci_irq, qemu_irq cmos_s3)
 {
-    acpi_pm_tmr_init(&pm->acpi_regs, ich9_pm_update_sci_fn);
-    acpi_pm1_cnt_init(&pm->acpi_regs);
+    memory_region_init(&pm->io, "ich9-pm", ICH9_PMIO_SIZE);
+    memory_region_set_enabled(&pm->io, false);
+    memory_region_add_subregion(get_system_io(), 0, &pm->io);
+
+    acpi_pm_tmr_init(&pm->acpi_regs, ich9_pm_update_sci_fn, &pm->io);
+    acpi_pm1_evt_init(&pm->acpi_regs, ich9_pm_update_sci_fn, &pm->io);
+    acpi_pm1_cnt_init(&pm->acpi_regs, &pm->io);
+
     acpi_gpe_init(&pm->acpi_regs, ICH9_PMIO_GPE0_LEN);
+    memory_region_init_io(&pm->io_gpe, &ich9_gpe_ops, pm, "apci-gpe0",
+                          ICH9_PMIO_GPE0_LEN);
+    memory_region_add_subregion(&pm->io, ICH9_PMIO_GPE0_STS, &pm->io_gpe);
+
+    memory_region_init_io(&pm->io_smi, &ich9_smi_ops, pm, "apci-smi",
+                          8);
+    memory_region_add_subregion(&pm->io, ICH9_PMIO_SMI_EN, &pm->io_smi);
 
     pm->irq = sci_irq;
     qemu_register_reset(pm_reset, pm);
diff --git a/hw/acpi_ich9.h b/hw/acpi_ich9.h
index 180c40673b..bc221d3cbc 100644
--- a/hw/acpi_ich9.h
+++ b/hw/acpi_ich9.h
@@ -30,6 +30,9 @@ typedef struct ICH9LPCPMRegs {
      * PM1a_CNT_BLK = 2 in FADT so it is defined as uint16_t.
      */
     ACPIREGS acpi_regs;
+    MemoryRegion io;
+    MemoryRegion io_gpe;
+    MemoryRegion io_smi;
     uint32_t smi_en;
     uint32_t smi_sts;
 
diff --git a/hw/acpi_piix4.c b/hw/acpi_piix4.c
index dbddde13ab..0b5b0d3d3e 100644
--- a/hw/acpi_piix4.c
+++ b/hw/acpi_piix4.c
@@ -28,6 +28,7 @@
 #include "range.h"
 #include "ioport.h"
 #include "fw_cfg.h"
+#include "exec-memory.h"
 
 //#define DEBUG
 
@@ -37,10 +38,11 @@
 # define PIIX4_DPRINTF(format, ...)     do { } while (0)
 #endif
 
-#define ACPI_DBG_IO_ADDR  0xb044
-
 #define GPE_BASE 0xafe0
 #define GPE_LEN 4
+
+#define PCI_HOTPLUG_ADDR 0xae00
+#define PCI_HOTPLUG_SIZE 0x000f
 #define PCI_UP_BASE 0xae00
 #define PCI_DOWN_BASE 0xae04
 #define PCI_EJ_BASE 0xae08
@@ -55,7 +57,9 @@ struct pci_status {
 
 typedef struct PIIX4PMState {
     PCIDevice dev;
-    IORange ioport;
+    MemoryRegion io;
+    MemoryRegion io_gpe;
+    MemoryRegion io_pci;
     ACPIREGS ar;
 
     APMState apm;
@@ -109,67 +113,6 @@ static void pm_tmr_timer(ACPIREGS *ar)
     pm_update_sci(s);
 }
 
-static void pm_ioport_write(IORange *ioport, uint64_t addr, unsigned width,
-                            uint64_t val)
-{
-    PIIX4PMState *s = container_of(ioport, PIIX4PMState, ioport);
-
-    if (width != 2) {
-        PIIX4_DPRINTF("PM write port=0x%04x width=%d val=0x%08x\n",
-                      (unsigned)addr, width, (unsigned)val);
-    }
-
-    switch(addr) {
-    case 0x00:
-        acpi_pm1_evt_write_sts(&s->ar, val);
-        pm_update_sci(s);
-        break;
-    case 0x02:
-        acpi_pm1_evt_write_en(&s->ar, val);
-        pm_update_sci(s);
-        break;
-    case 0x04:
-        acpi_pm1_cnt_write(&s->ar, val, s->s4_val);
-        break;
-    default:
-        break;
-    }
-    PIIX4_DPRINTF("PM writew port=0x%04x val=0x%04x\n", (unsigned int)addr,
-                  (unsigned int)val);
-}
-
-static void pm_ioport_read(IORange *ioport, uint64_t addr, unsigned width,
-                            uint64_t *data)
-{
-    PIIX4PMState *s = container_of(ioport, PIIX4PMState, ioport);
-    uint32_t val;
-
-    switch(addr) {
-    case 0x00:
-        val = acpi_pm1_evt_get_sts(&s->ar);
-        break;
-    case 0x02:
-        val = s->ar.pm1.evt.en;
-        break;
-    case 0x04:
-        val = s->ar.pm1.cnt.cnt;
-        break;
-    case 0x08:
-        val = acpi_pm_tmr_get(&s->ar);
-        break;
-    default:
-        val = 0;
-        break;
-    }
-    PIIX4_DPRINTF("PM readw port=0x%04x val=0x%04x\n", (unsigned int)addr, val);
-    *data = val;
-}
-
-static const IORangeOps pm_iorange_ops = {
-    .read = pm_ioport_read,
-    .write = pm_ioport_write,
-};
-
 static void apm_ctrl_changed(uint32_t val, void *arg)
 {
     PIIX4PMState *s = arg;
@@ -184,32 +127,42 @@ static void apm_ctrl_changed(uint32_t val, void *arg)
     }
 }
 
-static void acpi_dbg_writel(void *opaque, uint32_t addr, uint32_t val)
-{
-    PIIX4_DPRINTF("ACPI: DBG: 0x%08x\n", val);
-}
-
 static void pm_io_space_update(PIIX4PMState *s)
 {
     uint32_t pm_io_base;
 
-    if (s->dev.config[0x80] & 1) {
-        pm_io_base = le32_to_cpu(*(uint32_t *)(s->dev.config + 0x40));
-        pm_io_base &= 0xffc0;
+    pm_io_base = le32_to_cpu(*(uint32_t *)(s->dev.config + 0x40));
+    pm_io_base &= 0xffc0;
 
-        /* XXX: need to improve memory and ioport allocation */
-        PIIX4_DPRINTF("PM: mapping to 0x%x\n", pm_io_base);
-        iorange_init(&s->ioport, &pm_iorange_ops, pm_io_base, 64);
-        ioport_register(&s->ioport);
-    }
+    memory_region_transaction_begin();
+    memory_region_set_enabled(&s->io, s->dev.config[0x80] & 1);
+    memory_region_set_address(&s->io, pm_io_base);
+    memory_region_transaction_commit();
+}
+
+static void smbus_io_space_update(PIIX4PMState *s)
+{
+    s->smb_io_base = le32_to_cpu(*(uint32_t *)(s->dev.config + 0x90));
+    s->smb_io_base &= 0xffc0;
+
+    memory_region_transaction_begin();
+    memory_region_set_enabled(&s->smb.io, s->dev.config[0xd2] & 1);
+    memory_region_set_address(&s->smb.io, s->smb_io_base);
+    memory_region_transaction_commit();
 }
 
 static void pm_write_config(PCIDevice *d,
                             uint32_t address, uint32_t val, int len)
 {
     pci_default_write_config(d, address, val, len);
-    if (range_covers_byte(address, len, 0x80))
+    if (range_covers_byte(address, len, 0x80) ||
+        ranges_overlap(address, len, 0x40, 4)) {
         pm_io_space_update((PIIX4PMState *)d);
+    }
+    if (range_covers_byte(address, len, 0xd2) ||
+        ranges_overlap(address, len, 0x90, 4)) {
+        smbus_io_space_update((PIIX4PMState *)d);
+    }
 }
 
 static void vmstate_pci_status_pre_save(void *opaque)
@@ -440,8 +393,6 @@ static int piix4_pm_initfn(PCIDevice *dev)
     /* APM */
     apm_init(dev, &s->apm, apm_ctrl_changed, s);
 
-    register_ioport_write(ACPI_DBG_IO_ADDR, 4, 4, acpi_dbg_writel, s);
-
     if (s->kvm_enabled) {
         /* Mark SMM as already inited to prevent SMM from running.  KVM does not
          * support SMM mode. */
@@ -453,16 +404,22 @@ static int piix4_pm_initfn(PCIDevice *dev)
     pci_conf[0x90] = s->smb_io_base | 1;
     pci_conf[0x91] = s->smb_io_base >> 8;
     pci_conf[0xd2] = 0x09;
-    register_ioport_write(s->smb_io_base, 64, 1, smb_ioport_writeb, &s->smb);
-    register_ioport_read(s->smb_io_base, 64, 1, smb_ioport_readb, &s->smb);
+    pm_smbus_init(&s->dev.qdev, &s->smb);
+    memory_region_set_enabled(&s->smb.io, pci_conf[0xd2] & 1);
+    memory_region_add_subregion(get_system_io(), s->smb_io_base, &s->smb.io);
 
-    acpi_pm_tmr_init(&s->ar, pm_tmr_timer);
+    memory_region_init(&s->io, "piix4-pm", 64);
+    memory_region_set_enabled(&s->io, false);
+    memory_region_add_subregion(get_system_io(), 0, &s->io);
+
+    acpi_pm_tmr_init(&s->ar, pm_tmr_timer, &s->io);
+    acpi_pm1_evt_init(&s->ar, pm_tmr_timer, &s->io);
+    acpi_pm1_cnt_init(&s->ar, &s->io);
     acpi_gpe_init(&s->ar, GPE_LEN);
 
     s->powerdown_notifier.notify = piix4_pm_powerdown_req;
     qemu_register_powerdown_notifier(&s->powerdown_notifier);
 
-    pm_smbus_init(&s->dev.qdev, &s->smb);
     s->machine_ready.notify = piix4_pm_machine_ready;
     qemu_add_machine_init_done_notifier(&s->machine_ready);
     qemu_register_reset(piix4_reset, s);
@@ -483,7 +440,6 @@ i2c_bus *piix4_pm_init(PCIBus *bus, int devfn, uint32_t smb_io_base,
 
     s = DO_UPCAST(PIIX4PMState, dev, dev);
     s->irq = sci_irq;
-    acpi_pm1_cnt_init(&s->ar);
     s->smi_irq = smi_irq;
     s->kvm_enabled = kvm_enabled;
 
@@ -540,7 +496,7 @@ static void piix4_pm_register_types(void)
 
 type_init(piix4_pm_register_types)
 
-static uint32_t gpe_readb(void *opaque, uint32_t addr)
+static uint64_t gpe_readb(void *opaque, hwaddr addr, unsigned width)
 {
     PIIX4PMState *s = opaque;
     uint32_t val = acpi_gpe_ioport_readb(&s->ar, addr);
@@ -549,7 +505,8 @@ static uint32_t gpe_readb(void *opaque, uint32_t addr)
     return val;
 }
 
-static void gpe_writeb(void *opaque, uint32_t addr, uint32_t val)
+static void gpe_writeb(void *opaque, hwaddr addr, uint64_t val,
+                       unsigned width)
 {
     PIIX4PMState *s = opaque;
 
@@ -559,6 +516,16 @@ static void gpe_writeb(void *opaque, uint32_t addr, uint32_t val)
     PIIX4_DPRINTF("gpe write %x <== %d\n", addr, val);
 }
 
+static const MemoryRegionOps piix4_gpe_ops = {
+    .read = gpe_readb,
+    .write = gpe_writeb,
+    .valid.min_access_size = 1,
+    .valid.max_access_size = 4,
+    .impl.min_access_size = 1,
+    .impl.max_access_size = 1,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
 static uint32_t pci_up_read(void *opaque, uint32_t addr)
 {
     PIIX4PMState *s = opaque;
@@ -602,24 +569,40 @@ static uint32_t pcirmv_read(void *opaque, uint32_t addr)
     return s->pci0_hotplug_enable;
 }
 
+static const MemoryRegionOps piix4_pci_ops = {
+    .old_portio = (MemoryRegionPortio[]) {
+        {
+            .offset = PCI_UP_BASE - PCI_HOTPLUG_ADDR,   .len = 4, .size = 4,
+            .read = pci_up_read,
+        },{
+            .offset = PCI_DOWN_BASE - PCI_HOTPLUG_ADDR, .len = 4, .size = 4,
+            .read = pci_down_read,
+        },{
+            .offset = PCI_EJ_BASE - PCI_HOTPLUG_ADDR,   .len = 4, .size = 4,
+            .read = pci_features_read,
+            .write = pciej_write,
+        },{
+            .offset = PCI_RMV_BASE - PCI_HOTPLUG_ADDR,  .len = 4, .size = 4,
+            .read = pcirmv_read,
+        },
+        PORTIO_END_OF_LIST()
+    },
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
 static int piix4_device_hotplug(DeviceState *qdev, PCIDevice *dev,
                                 PCIHotplugState state);
 
 static void piix4_acpi_system_hot_add_init(PCIBus *bus, PIIX4PMState *s)
 {
+    memory_region_init_io(&s->io_gpe, &piix4_gpe_ops, s, "apci-gpe0",
+                          GPE_LEN);
+    memory_region_add_subregion(get_system_io(), GPE_BASE, &s->io_gpe);
 
-    register_ioport_write(GPE_BASE, GPE_LEN, 1, gpe_writeb, s);
-    register_ioport_read(GPE_BASE, GPE_LEN, 1,  gpe_readb, s);
-    acpi_gpe_blk(&s->ar, GPE_BASE);
-
-    register_ioport_read(PCI_UP_BASE, 4, 4, pci_up_read, s);
-    register_ioport_read(PCI_DOWN_BASE, 4, 4, pci_down_read, s);
-
-    register_ioport_write(PCI_EJ_BASE, 4, 4, pciej_write, s);
-    register_ioport_read(PCI_EJ_BASE, 4, 4,  pci_features_read, s);
-
-    register_ioport_read(PCI_RMV_BASE, 4, 4,  pcirmv_read, s);
-
+    memory_region_init_io(&s->io_pci, &piix4_pci_ops, s, "apci-pci-hotplug",
+                          PCI_HOTPLUG_SIZE);
+    memory_region_add_subregion(get_system_io(), PCI_HOTPLUG_ADDR,
+                                &s->io_pci);
     pci_bus_hotplug(bus, piix4_device_hotplug, &s->dev.qdev);
 }
 
diff --git a/hw/ich9.h b/hw/ich9.h
index de491350c3..34e216f142 100644
--- a/hw/ich9.h
+++ b/hw/ich9.h
@@ -51,6 +51,7 @@ typedef struct ICH9LPCState {
     /* isa bus */
     ISABus *isa_bus;
     MemoryRegion rbca_mem;
+    Notifier machine_ready;
 
     qemu_irq *pic;
     qemu_irq *ioapic;
diff --git a/hw/lpc_ich9.c b/hw/lpc_ich9.c
index 7de5427a69..878a43e92c 100644
--- a/hw/lpc_ich9.c
+++ b/hw/lpc_ich9.c
@@ -60,6 +60,7 @@
 #include "pam.h"
 #include "pci_internals.h"
 #include "exec-memory.h"
+#include "sysemu.h"
 
 static int ich9_lpc_sci_irq(ICH9LPCState *lpc);
 
@@ -456,6 +457,30 @@ static const MemoryRegionOps rbca_mmio_ops = {
     .endianness = DEVICE_LITTLE_ENDIAN,
 };
 
+static void ich9_lpc_machine_ready(Notifier *n, void *opaque)
+{
+    ICH9LPCState *s = container_of(n, ICH9LPCState, machine_ready);
+    uint8_t *pci_conf;
+
+    pci_conf = s->d.config;
+    if (isa_is_ioport_assigned(0x3f8)) {
+        /* com1 */
+        pci_conf[0x82] |= 0x01;
+    }
+    if (isa_is_ioport_assigned(0x2f8)) {
+        /* com2 */
+        pci_conf[0x82] |= 0x02;
+    }
+    if (isa_is_ioport_assigned(0x378)) {
+        /* lpt */
+        pci_conf[0x82] |= 0x04;
+    }
+    if (isa_is_ioport_assigned(0x3f0)) {
+        /* floppy */
+        pci_conf[0x82] |= 0x08;
+    }
+}
+
 static int ich9_lpc_initfn(PCIDevice *d)
 {
     ICH9LPCState *lpc = ICH9_LPC_DEVICE(d);
@@ -473,6 +498,10 @@ static int ich9_lpc_initfn(PCIDevice *d)
 
     ich9_cc_init(lpc);
     apm_init(d, &lpc->apm, ich9_apm_ctrl_changed, lpc);
+
+    lpc->machine_ready.notify = ich9_lpc_machine_ready;
+    qemu_add_machine_init_done_notifier(&lpc->machine_ready);
+
     return 0;
 }
 
diff --git a/hw/pm_smbus.c b/hw/pm_smbus.c
index 5d6046de5a..ea1380ca68 100644
--- a/hw/pm_smbus.c
+++ b/hw/pm_smbus.c
@@ -94,10 +94,11 @@ static void smb_transaction(PMSMBus *s)
     s->smb_stat |= 0x04;
 }
 
-void smb_ioport_writeb(void *opaque, uint32_t addr, uint32_t val)
+static void smb_ioport_writeb(void *opaque, hwaddr addr, uint64_t val,
+                              unsigned width)
 {
     PMSMBus *s = opaque;
-    addr &= 0x3f;
+
     SMBUS_DPRINTF("SMB writeb port=0x%04x val=0x%02x\n", addr, val);
     switch(addr) {
     case SMBHSTSTS:
@@ -131,12 +132,11 @@ void smb_ioport_writeb(void *opaque, uint32_t addr, uint32_t val)
     }
 }
 
-uint32_t smb_ioport_readb(void *opaque, uint32_t addr)
+static uint64_t smb_ioport_readb(void *opaque, hwaddr addr, unsigned width)
 {
     PMSMBus *s = opaque;
     uint32_t val;
 
-    addr &= 0x3f;
     switch(addr) {
     case SMBHSTSTS:
         val = s->smb_stat;
@@ -170,7 +170,16 @@ uint32_t smb_ioport_readb(void *opaque, uint32_t addr)
     return val;
 }
 
+static const MemoryRegionOps pm_smbus_ops = {
+    .read = smb_ioport_readb,
+    .write = smb_ioport_writeb,
+    .valid.min_access_size = 1,
+    .valid.max_access_size = 1,
+    .endianness = DEVICE_LITTLE_ENDIAN,
+};
+
 void pm_smbus_init(DeviceState *parent, PMSMBus *smb)
 {
     smb->smbus = i2c_init_bus(parent, "i2c");
+    memory_region_init_io(&smb->io, &pm_smbus_ops, smb, "pm-smbus", 64);
 }
diff --git a/hw/pm_smbus.h b/hw/pm_smbus.h
index 4750a409f9..e3069bf7d4 100644
--- a/hw/pm_smbus.h
+++ b/hw/pm_smbus.h
@@ -3,6 +3,7 @@
 
 typedef struct PMSMBus {
     i2c_bus *smbus;
+    MemoryRegion io;
 
     uint8_t smb_stat;
     uint8_t smb_ctl;
@@ -15,7 +16,5 @@ typedef struct PMSMBus {
 } PMSMBus;
 
 void pm_smbus_init(DeviceState *parent, PMSMBus *smb);
-void smb_ioport_writeb(void *opaque, uint32_t addr, uint32_t val);
-uint32_t smb_ioport_readb(void *opaque, uint32_t addr);
 
 #endif /* !PM_SMBUS_H */
diff --git a/hw/smbus_ich9.c b/hw/smbus_ich9.c
index 6940583bb6..4194785d71 100644
--- a/hw/smbus_ich9.c
+++ b/hw/smbus_ich9.c
@@ -40,7 +40,6 @@ typedef struct ICH9SMBState {
     PCIDevice dev;
 
     PMSMBus smb;
-    MemoryRegion mem_bar;
 } ICH9SMBState;
 
 static const VMStateDescription vmstate_ich9_smbus = {
@@ -54,42 +53,23 @@ static const VMStateDescription vmstate_ich9_smbus = {
     }
 };
 
-static void ich9_smb_ioport_writeb(void *opaque, hwaddr addr,
-                                   uint64_t val, unsigned size)
+static void ich9_smbus_write_config(PCIDevice *d, uint32_t address,
+                                    uint32_t val, int len)
 {
-    ICH9SMBState *s = opaque;
-    uint8_t hostc = s->dev.config[ICH9_SMB_HOSTC];
+    ICH9SMBState *s = ICH9_SMB_DEVICE(d);
 
-    if ((hostc & ICH9_SMB_HOSTC_HST_EN) && !(hostc & ICH9_SMB_HOSTC_I2C_EN)) {
-        uint64_t offset = addr - s->dev.io_regions[ICH9_SMB_SMB_BASE_BAR].addr;
-        smb_ioport_writeb(&s->smb, offset, val);
+    pci_default_write_config(d, address, val, len);
+    if (range_covers_byte(address, len, ICH9_SMB_HOSTC)) {
+        uint8_t hostc = s->dev.config[ICH9_SMB_HOSTC];
+        if ((hostc & ICH9_SMB_HOSTC_HST_EN) &&
+            !(hostc & ICH9_SMB_HOSTC_I2C_EN)) {
+            memory_region_set_enabled(&s->smb.io, true);
+        } else {
+            memory_region_set_enabled(&s->smb.io, false);
+        }
     }
 }
 
-static uint64_t ich9_smb_ioport_readb(void *opaque, hwaddr addr,
-                                      unsigned size)
-{
-    ICH9SMBState *s = opaque;
-    uint8_t hostc = s->dev.config[ICH9_SMB_HOSTC];
-
-    if ((hostc & ICH9_SMB_HOSTC_HST_EN) && !(hostc & ICH9_SMB_HOSTC_I2C_EN)) {
-        uint64_t offset = addr - s->dev.io_regions[ICH9_SMB_SMB_BASE_BAR].addr;
-        return smb_ioport_readb(&s->smb, offset);
-    }
-
-    return 0xff;
-}
-
-static const MemoryRegionOps lpc_smb_mmio_ops = {
-    .read = ich9_smb_ioport_readb,
-    .write = ich9_smb_ioport_writeb,
-    .endianness = DEVICE_LITTLE_ENDIAN,
-    .impl = {
-        .min_access_size = 1,
-        .max_access_size = 1,
-    },
-};
-
 static int ich9_smbus_initfn(PCIDevice *d)
 {
     ICH9SMBState *s = ICH9_SMB_DEVICE(d);
@@ -97,27 +77,12 @@ static int ich9_smbus_initfn(PCIDevice *d)
     /* TODO? D31IP.SMIP in chipset configuration space */
     pci_config_set_interrupt_pin(d->config, 0x01); /* interrupt pin 1 */
 
-    pci_set_byte(d->config + ICH9_SMB_HOSTC, 0);
-
-    /*
-     * update parameters based on
-     * paralell_hds[0]
-     * serial_hds[0]
-     * serial_hds[0]
-     * fdc
-     *
-     * Is there any OS that depends on them?
-     */
-
-    /* TODO smb_io_base */
     pci_set_byte(d->config + ICH9_SMB_HOSTC, 0);
     /* TODO bar0, bar1: 64bit BAR support*/
 
-    memory_region_init_io(&s->mem_bar, &lpc_smb_mmio_ops, s, "ich9-smbus-bar",
-                            ICH9_SMB_SMB_BASE_SIZE);
-    pci_register_bar(d, ICH9_SMB_SMB_BASE_BAR, PCI_BASE_ADDRESS_SPACE_IO,
-                        &s->mem_bar);
     pm_smbus_init(&d->qdev, &s->smb);
+    pci_register_bar(d, ICH9_SMB_SMB_BASE_BAR, PCI_BASE_ADDRESS_SPACE_IO,
+                     &s->smb.io);
     return 0;
 }
 
@@ -134,6 +99,7 @@ static void ich9_smb_class_init(ObjectClass *klass, void *data)
     dc->vmsd = &vmstate_ich9_smbus;
     dc->desc = "ICH9 SMBUS Bridge";
     k->init = ich9_smbus_initfn;
+    k->config_write = ich9_smbus_write_config;
 }
 
 i2c_bus *ich9_smb_init(PCIBus *bus, int devfn, uint32_t smb_io_base)
diff --git a/hw/vt82c686.c b/hw/vt82c686.c
index 7f11dbe782..57d16c0134 100644
--- a/hw/vt82c686.c
+++ b/hw/vt82c686.c
@@ -24,6 +24,7 @@
 #include "pm_smbus.h"
 #include "sysemu.h"
 #include "qemu-timer.h"
+#include "exec-memory.h"
 
 typedef uint32_t pci_addr_t;
 #include "pci_host.h"
@@ -159,6 +160,7 @@ static void vt82c686b_write_config(PCIDevice * d, uint32_t address,
 
 typedef struct VT686PMState {
     PCIDevice dev;
+    MemoryRegion io;
     ACPIREGS ar;
     APMState apm;
     PMSMBus smb;
@@ -195,92 +197,17 @@ static void pm_tmr_timer(ACPIREGS *ar)
     pm_update_sci(s);
 }
 
-static void pm_ioport_writew(void *opaque, uint32_t addr, uint32_t val)
-{
-    VT686PMState *s = opaque;
-
-    addr &= 0x0f;
-    switch (addr) {
-    case 0x00:
-        acpi_pm1_evt_write_sts(&s->ar, val);
-        pm_update_sci(s);
-        break;
-    case 0x02:
-        acpi_pm1_evt_write_en(&s->ar, val);
-        pm_update_sci(s);
-        break;
-    case 0x04:
-        acpi_pm1_cnt_write(&s->ar, val, 0);
-        break;
-    default:
-        break;
-    }
-    DPRINTF("PM writew port=0x%04x val=0x%02x\n", addr, val);
-}
-
-static uint32_t pm_ioport_readw(void *opaque, uint32_t addr)
-{
-    VT686PMState *s = opaque;
-    uint32_t val;
-
-    addr &= 0x0f;
-    switch (addr) {
-    case 0x00:
-        val = acpi_pm1_evt_get_sts(&s->ar);
-        break;
-    case 0x02:
-        val = s->ar.pm1.evt.en;
-        break;
-    case 0x04:
-        val = s->ar.pm1.cnt.cnt;
-        break;
-    default:
-        val = 0;
-        break;
-    }
-    DPRINTF("PM readw port=0x%04x val=0x%02x\n", addr, val);
-    return val;
-}
-
-static void pm_ioport_writel(void *opaque, uint32_t addr, uint32_t val)
-{
-    addr &= 0x0f;
-    DPRINTF("PM writel port=0x%04x val=0x%08x\n", addr, val);
-}
-
-static uint32_t pm_ioport_readl(void *opaque, uint32_t addr)
-{
-    VT686PMState *s = opaque;
-    uint32_t val;
-
-    addr &= 0x0f;
-    switch (addr) {
-    case 0x08:
-        val = acpi_pm_tmr_get(&s->ar);
-        break;
-    default:
-        val = 0;
-        break;
-    }
-    DPRINTF("PM readl port=0x%04x val=0x%08x\n", addr, val);
-    return val;
-}
-
 static void pm_io_space_update(VT686PMState *s)
 {
     uint32_t pm_io_base;
 
-    if (s->dev.config[0x80] & 1) {
-        pm_io_base = pci_get_long(s->dev.config + 0x40);
-        pm_io_base &= 0xffc0;
+    pm_io_base = pci_get_long(s->dev.config + 0x40);
+    pm_io_base &= 0xffc0;
 
-        /* XXX: need to improve memory and ioport allocation */
-        DPRINTF("PM: mapping to 0x%x\n", pm_io_base);
-        register_ioport_write(pm_io_base, 64, 2, pm_ioport_writew, s);
-        register_ioport_read(pm_io_base, 64, 2, pm_ioport_readw, s);
-        register_ioport_write(pm_io_base, 64, 4, pm_ioport_writel, s);
-        register_ioport_read(pm_io_base, 64, 4, pm_ioport_readl, s);
-    }
+    memory_region_transaction_begin();
+    memory_region_set_enabled(&s->io, s->dev.config[0x80] & 1);
+    memory_region_set_address(&s->io, pm_io_base);
+    memory_region_transaction_commit();
 }
 
 static void pm_write_config(PCIDevice *d,
@@ -424,15 +351,18 @@ static int vt82c686b_pm_initfn(PCIDevice *dev)
     pci_conf[0x90] = s->smb_io_base | 1;
     pci_conf[0x91] = s->smb_io_base >> 8;
     pci_conf[0xd2] = 0x90;
-    register_ioport_write(s->smb_io_base, 0xf, 1, smb_ioport_writeb, &s->smb);
-    register_ioport_read(s->smb_io_base, 0xf, 1, smb_ioport_readb, &s->smb);
+    pm_smbus_init(&s->dev.qdev, &s->smb);
+    memory_region_add_subregion(get_system_io(), s->smb_io_base, &s->smb.io);
 
     apm_init(dev, &s->apm, NULL, s);
 
-    acpi_pm_tmr_init(&s->ar, pm_tmr_timer);
-    acpi_pm1_cnt_init(&s->ar);
+    memory_region_init(&s->io, "vt82c686-pm", 64);
+    memory_region_set_enabled(&s->io, false);
+    memory_region_add_subregion(get_system_io(), 0, &s->io);
 
-    pm_smbus_init(&s->dev.qdev, &s->smb);
+    acpi_pm_tmr_init(&s->ar, pm_tmr_timer, &s->io);
+    acpi_pm1_evt_init(&s->ar, pm_tmr_timer, &s->io);
+    acpi_pm1_cnt_init(&s->ar, &s->io);
 
     return 0;
 }