diff --git a/hw/acpi.c b/hw/acpi.c
index 79b179b..1922e53 100644
--- a/hw/acpi.c
+++ b/hw/acpi.c
@@ -249,63 +249,61 @@ int acpi_table_add(const char *t)
 }
 
 /* ACPI PM1a EVT */
-uint16_t acpi_pm1_evt_get_sts(ACPIPM1EVT *pm1, int64_t overflow_time)
+uint16_t acpi_pm1_evt_get_sts(ACPIREGS *ar, int64_t overflow_time)
 {
     int64_t d = acpi_pm_tmr_get_clock();
     if (d >= overflow_time) {
-        pm1->sts |= ACPI_BITMASK_TIMER_STATUS;
+        ar->pm1.evt.sts |= ACPI_BITMASK_TIMER_STATUS;
     }
-    return pm1->sts;
+    return ar->pm1.evt.sts;
 }
 
-void acpi_pm1_evt_write_sts(ACPIPM1EVT *pm1, ACPIPMTimer *tmr, uint16_t val)
+void acpi_pm1_evt_write_sts(ACPIREGS *ar, uint16_t val)
 {
-    uint16_t pm1_sts = acpi_pm1_evt_get_sts(pm1, tmr->overflow_time);
+    uint16_t pm1_sts = acpi_pm1_evt_get_sts(ar, ar->tmr.overflow_time);
     if (pm1_sts & val & ACPI_BITMASK_TIMER_STATUS) {
         /* if TMRSTS is reset, then compute the new overflow time */
-        acpi_pm_tmr_calc_overflow_time(tmr);
+        acpi_pm_tmr_calc_overflow_time(ar);
     }
-    pm1->sts &= ~val;
+    ar->pm1.evt.sts &= ~val;
 }
 
-void acpi_pm1_evt_power_down(ACPIPM1EVT *pm1, ACPIPMTimer *tmr)
+void acpi_pm1_evt_power_down(ACPIREGS *ar)
 {
-    if (!pm1) {
-        qemu_system_shutdown_request();
-    } else if (pm1->en & ACPI_BITMASK_POWER_BUTTON_ENABLE) {
-        pm1->sts |= ACPI_BITMASK_POWER_BUTTON_STATUS;
-        tmr->update_sci(tmr);
+    if (ar->pm1.evt.en & ACPI_BITMASK_POWER_BUTTON_ENABLE) {
+        ar->pm1.evt.sts |= ACPI_BITMASK_POWER_BUTTON_STATUS;
+        ar->tmr.update_sci(ar);
     }
 }
 
-void acpi_pm1_evt_reset(ACPIPM1EVT *pm1)
+void acpi_pm1_evt_reset(ACPIREGS *ar)
 {
-    pm1->sts = 0;
-    pm1->en = 0;
+    ar->pm1.evt.sts = 0;
+    ar->pm1.evt.en = 0;
 }
 
 /* ACPI PM_TMR */
-void acpi_pm_tmr_update(ACPIPMTimer *tmr, bool enable)
+void acpi_pm_tmr_update(ACPIREGS *ar, bool enable)
 {
     int64_t expire_time;
 
     /* schedule a timer interruption if needed */
     if (enable) {
-        expire_time = muldiv64(tmr->overflow_time, get_ticks_per_sec(),
+        expire_time = muldiv64(ar->tmr.overflow_time, get_ticks_per_sec(),
                                PM_TIMER_FREQUENCY);
-        qemu_mod_timer(tmr->timer, expire_time);
+        qemu_mod_timer(ar->tmr.timer, expire_time);
     } else {
-        qemu_del_timer(tmr->timer);
+        qemu_del_timer(ar->tmr.timer);
     }
 }
 
-void acpi_pm_tmr_calc_overflow_time(ACPIPMTimer *tmr)
+void acpi_pm_tmr_calc_overflow_time(ACPIREGS *ar)
 {
     int64_t d = acpi_pm_tmr_get_clock();
-    tmr->overflow_time = (d + 0x800000LL) & ~0x7fffffLL;
+    ar->tmr.overflow_time = (d + 0x800000LL) & ~0x7fffffLL;
 }
 
-uint32_t acpi_pm_tmr_get(ACPIPMTimer *tmr)
+uint32_t acpi_pm_tmr_get(ACPIREGS *ar)
 {
     uint32_t d = acpi_pm_tmr_get_clock();
     return d & 0xffffff;
@@ -313,31 +311,31 @@ uint32_t acpi_pm_tmr_get(ACPIPMTimer *tmr)
 
 static void acpi_pm_tmr_timer(void *opaque)
 {
-    ACPIPMTimer *tmr = opaque;
-    tmr->update_sci(tmr);
+    ACPIREGS *ar = opaque;
+    ar->tmr.update_sci(ar);
 }
 
-void acpi_pm_tmr_init(ACPIPMTimer *tmr, acpi_update_sci_fn update_sci)
+void acpi_pm_tmr_init(ACPIREGS *ar, acpi_update_sci_fn update_sci)
 {
-    tmr->update_sci = update_sci;
-    tmr->timer = qemu_new_timer_ns(vm_clock, acpi_pm_tmr_timer, tmr);
+    ar->tmr.update_sci = update_sci;
+    ar->tmr.timer = qemu_new_timer_ns(vm_clock, acpi_pm_tmr_timer, ar);
 }
 
-void acpi_pm_tmr_reset(ACPIPMTimer *tmr)
+void acpi_pm_tmr_reset(ACPIREGS *ar)
 {
-    tmr->overflow_time = 0;
-    qemu_del_timer(tmr->timer);
+    ar->tmr.overflow_time = 0;
+    qemu_del_timer(ar->tmr.timer);
 }
 
 /* ACPI PM1aCNT */
-void acpi_pm1_cnt_init(ACPIPM1CNT *pm1_cnt, qemu_irq cmos_s3)
+void acpi_pm1_cnt_init(ACPIREGS *ar, qemu_irq cmos_s3)
 {
-    pm1_cnt->cmos_s3 = cmos_s3;
+    ar->pm1.cnt.cmos_s3 = cmos_s3;
 }
 
-void acpi_pm1_cnt_write(ACPIPM1EVT *pm1a, ACPIPM1CNT *pm1_cnt, uint16_t val)
+void acpi_pm1_cnt_write(ACPIREGS *ar, uint16_t val)
 {
-    pm1_cnt->cnt = val & ~(ACPI_BITMASK_SLEEP_ENABLE);
+    ar->pm1.cnt.cnt = val & ~(ACPI_BITMASK_SLEEP_ENABLE);
 
     if (val & ACPI_BITMASK_SLEEP_ENABLE) {
         /* change suspend type */
@@ -349,62 +347,62 @@ void acpi_pm1_cnt_write(ACPIPM1EVT *pm1a, ACPIPM1CNT *pm1_cnt, uint16_t val)
         case 1:
             /* ACPI_BITMASK_WAKE_STATUS should be set on resume.
                Pretend that resume was caused by power button */
-            pm1a->sts |=
+            ar->pm1.evt.sts |=
                 (ACPI_BITMASK_WAKE_STATUS | ACPI_BITMASK_POWER_BUTTON_STATUS);
             qemu_system_reset_request();
-            qemu_irq_raise(pm1_cnt->cmos_s3);
+            qemu_irq_raise(ar->pm1.cnt.cmos_s3);
         default:
             break;
         }
     }
 }
 
-void acpi_pm1_cnt_update(ACPIPM1CNT *pm1_cnt,
+void acpi_pm1_cnt_update(ACPIREGS *ar,
                          bool sci_enable, bool sci_disable)
 {
     /* ACPI specs 3.0, 4.7.2.5 */
     if (sci_enable) {
-        pm1_cnt->cnt |= ACPI_BITMASK_SCI_ENABLE;
+        ar->pm1.cnt.cnt |= ACPI_BITMASK_SCI_ENABLE;
     } else if (sci_disable) {
-        pm1_cnt->cnt &= ~ACPI_BITMASK_SCI_ENABLE;
+        ar->pm1.cnt.cnt &= ~ACPI_BITMASK_SCI_ENABLE;
     }
 }
 
-void acpi_pm1_cnt_reset(ACPIPM1CNT *pm1_cnt)
+void acpi_pm1_cnt_reset(ACPIREGS *ar)
 {
-    pm1_cnt->cnt = 0;
-    if (pm1_cnt->cmos_s3) {
-        qemu_irq_lower(pm1_cnt->cmos_s3);
+    ar->pm1.cnt.cnt = 0;
+    if (ar->pm1.cnt.cmos_s3) {
+        qemu_irq_lower(ar->pm1.cnt.cmos_s3);
     }
 }
 
 /* ACPI GPE */
-void acpi_gpe_init(ACPIGPE *gpe, uint8_t len)
+void acpi_gpe_init(ACPIREGS *ar, uint8_t len)
 {
-    gpe->len = len;
-    gpe->sts = g_malloc0(len / 2);
-    gpe->en = g_malloc0(len / 2);
+    ar->gpe.len = len;
+    ar->gpe.sts = g_malloc0(len / 2);
+    ar->gpe.en = g_malloc0(len / 2);
 }
 
-void acpi_gpe_blk(ACPIGPE *gpe, uint32_t blk)
+void acpi_gpe_blk(ACPIREGS *ar, uint32_t blk)
 {
-    gpe->blk = blk;
+    ar->gpe.blk = blk;
 }
 
-void acpi_gpe_reset(ACPIGPE *gpe)
+void acpi_gpe_reset(ACPIREGS *ar)
 {
-    memset(gpe->sts, 0, gpe->len / 2);
-    memset(gpe->en, 0, gpe->len / 2);
+    memset(ar->gpe.sts, 0, ar->gpe.len / 2);
+    memset(ar->gpe.en, 0, ar->gpe.len / 2);
 }
 
-static uint8_t *acpi_gpe_ioport_get_ptr(ACPIGPE *gpe, uint32_t addr)
+static uint8_t *acpi_gpe_ioport_get_ptr(ACPIREGS *ar, uint32_t addr)
 {
     uint8_t *cur = NULL;
 
-    if (addr < gpe->len / 2) {
-        cur = gpe->sts + addr;
-    } else if (addr < gpe->len) {
-        cur = gpe->en + addr - gpe->len / 2;
+    if (addr < ar->gpe.len / 2) {
+        cur = ar->gpe.sts + addr;
+    } else if (addr < ar->gpe.len) {
+        cur = ar->gpe.en + addr - ar->gpe.len / 2;
     } else {
         abort();
     }
@@ -412,16 +410,16 @@ static uint8_t *acpi_gpe_ioport_get_ptr(ACPIGPE *gpe, uint32_t addr)
     return cur;
 }
 
-void acpi_gpe_ioport_writeb(ACPIGPE *gpe, uint32_t addr, uint32_t val)
+void acpi_gpe_ioport_writeb(ACPIREGS *ar, uint32_t addr, uint32_t val)
 {
     uint8_t *cur;
 
-    addr -= gpe->blk;
-    cur = acpi_gpe_ioport_get_ptr(gpe, addr);
-    if (addr < gpe->len / 2) {
+    addr -= ar->gpe.blk;
+    cur = acpi_gpe_ioport_get_ptr(ar, addr);
+    if (addr < ar->gpe.len / 2) {
         /* GPE_STS */
         *cur = (*cur) & ~val;
-    } else if (addr < gpe->len) {
+    } else if (addr < ar->gpe.len) {
         /* GPE_EN */
         *cur = val;
     } else {
@@ -429,13 +427,13 @@ void acpi_gpe_ioport_writeb(ACPIGPE *gpe, uint32_t addr, uint32_t val)
     }
 }
 
-uint32_t acpi_gpe_ioport_readb(ACPIGPE *gpe, uint32_t addr)
+uint32_t acpi_gpe_ioport_readb(ACPIREGS *ar, uint32_t addr)
 {
     uint8_t *cur;
     uint32_t val;
 
-    addr -= gpe->blk;
-    cur = acpi_gpe_ioport_get_ptr(gpe, addr);
+    addr -= ar->gpe.blk;
+    cur = acpi_gpe_ioport_get_ptr(ar, addr);
     val = 0;
     if (cur != NULL) {
         val = *cur;
diff --git a/hw/acpi.h b/hw/acpi.h
index 5c43b7d..530c86a 100644
--- a/hw/acpi.h
+++ b/hw/acpi.h
@@ -78,8 +78,9 @@ typedef struct ACPIPMTimer ACPIPMTimer;
 typedef struct ACPIPM1EVT ACPIPM1EVT;
 typedef struct ACPIPM1CNT ACPIPM1CNT;
 typedef struct ACPIGPE ACPIGPE;
+typedef struct ACPIREGS ACPIREGS;
 
-typedef void (*acpi_update_sci_fn)(ACPIPMTimer *tmr);
+typedef void (*acpi_update_sci_fn)(ACPIREGS *ar);
 
 struct ACPIPMTimer {
     QEMUTimer *timer;
@@ -106,12 +107,21 @@ struct ACPIGPE {
     uint8_t *en;
 };
 
+struct ACPIREGS {
+    ACPIPMTimer     tmr;
+    ACPIGPE         gpe;
+    struct {
+        ACPIPM1EVT  evt;
+        ACPIPM1CNT  cnt;
+    } pm1;
+};
+
 /* PM_TMR */
-void acpi_pm_tmr_update(ACPIPMTimer *tmr, bool enable);
-void acpi_pm_tmr_calc_overflow_time(ACPIPMTimer *tmr);
-uint32_t acpi_pm_tmr_get(ACPIPMTimer *tmr);
-void acpi_pm_tmr_init(ACPIPMTimer *tmr, acpi_update_sci_fn update_sci);
-void acpi_pm_tmr_reset(ACPIPMTimer *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_reset(ACPIREGS *ar);
 
 #include "qemu-timer.h"
 static inline int64_t acpi_pm_tmr_get_clock(void)
@@ -121,24 +131,24 @@ 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(ACPIPM1EVT *pm1, int64_t overflow_time);
-void acpi_pm1_evt_write_sts(ACPIPM1EVT *pm1, ACPIPMTimer *tmr, uint16_t val);
-void acpi_pm1_evt_power_down(ACPIPM1EVT *pm1, ACPIPMTimer *tmr);
-void acpi_pm1_evt_reset(ACPIPM1EVT *pm1);
+uint16_t acpi_pm1_evt_get_sts(ACPIREGS *ar, int64_t overflow_time);
+void acpi_pm1_evt_write_sts(ACPIREGS *ar, uint16_t val);
+void acpi_pm1_evt_power_down(ACPIREGS *ar);
+void acpi_pm1_evt_reset(ACPIREGS *ar);
 
 /* PM1a_CNT: piix and ich9 don't implement PM1b CNT. */
-void acpi_pm1_cnt_init(ACPIPM1CNT *pm1_cnt, qemu_irq cmos_s3);
-void acpi_pm1_cnt_write(ACPIPM1EVT *pm1a, ACPIPM1CNT *pm1_cnt, uint16_t val);
-void acpi_pm1_cnt_update(ACPIPM1CNT *pm1_cnt,
+void acpi_pm1_cnt_init(ACPIREGS *ar, qemu_irq cmos_s3);
+void acpi_pm1_cnt_write(ACPIREGS *ar, uint16_t val);
+void acpi_pm1_cnt_update(ACPIREGS *ar,
                          bool sci_enable, bool sci_disable);
-void acpi_pm1_cnt_reset(ACPIPM1CNT *pm1_cnt);
+void acpi_pm1_cnt_reset(ACPIREGS *ar);
 
 /* GPE0 */
-void acpi_gpe_init(ACPIGPE *gpe, uint8_t len);
-void acpi_gpe_blk(ACPIGPE *gpe, uint32_t blk);
-void acpi_gpe_reset(ACPIGPE *gpe);
+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(ACPIGPE *gpe, uint32_t addr, uint32_t val);
-uint32_t acpi_gpe_ioport_readb(ACPIGPE *gpe, uint32_t addr);
+void acpi_gpe_ioport_writeb(ACPIREGS *ar, uint32_t addr, uint32_t val);
+uint32_t acpi_gpe_ioport_readb(ACPIREGS *ar, uint32_t addr);
 
 #endif /* !QEMU_HW_ACPI_H */
diff --git a/hw/acpi_piix4.c b/hw/acpi_piix4.c
index 21484ae..afb37e2 100644
--- a/hw/acpi_piix4.c
+++ b/hw/acpi_piix4.c
@@ -54,13 +54,10 @@ struct pci_status {
 typedef struct PIIX4PMState {
     PCIDevice dev;
     IORange ioport;
-    ACPIPM1EVT pm1a;
-    ACPIPM1CNT pm1_cnt;
+    ACPIREGS ar;
 
     APMState apm;
 
-    ACPIPMTimer tmr;
-
     PMSMBus smb;
     uint32_t smb_io_base;
 
@@ -70,7 +67,6 @@ typedef struct PIIX4PMState {
     Notifier machine_ready;
 
     /* for pci hotplug */
-    ACPIGPE gpe;
     struct pci_status pci0_status;
     uint32_t pci0_hotplug_enable;
 } PIIX4PMState;
@@ -84,23 +80,24 @@ static void pm_update_sci(PIIX4PMState *s)
 {
     int sci_level, pmsts;
 
-    pmsts = acpi_pm1_evt_get_sts(&s->pm1a, s->tmr.overflow_time);
-    sci_level = (((pmsts & s->pm1a.en) &
+    pmsts = acpi_pm1_evt_get_sts(&s->ar, s->ar.tmr.overflow_time);
+    sci_level = (((pmsts & s->ar.pm1.evt.en) &
                   (ACPI_BITMASK_RT_CLOCK_ENABLE |
                    ACPI_BITMASK_POWER_BUTTON_ENABLE |
                    ACPI_BITMASK_GLOBAL_LOCK_ENABLE |
                    ACPI_BITMASK_TIMER_ENABLE)) != 0) ||
-        (((s->gpe.sts[0] & s->gpe.en[0]) & PIIX4_PCI_HOTPLUG_STATUS) != 0);
+        (((s->ar.gpe.sts[0] & s->ar.gpe.en[0])
+          & PIIX4_PCI_HOTPLUG_STATUS) != 0);
 
     qemu_set_irq(s->irq, sci_level);
     /* schedule a timer interruption if needed */
-    acpi_pm_tmr_update(&s->tmr, (s->pm1a.en & ACPI_BITMASK_TIMER_ENABLE) &&
+    acpi_pm_tmr_update(&s->ar, (s->ar.pm1.evt.en & ACPI_BITMASK_TIMER_ENABLE) &&
                        !(pmsts & ACPI_BITMASK_TIMER_STATUS));
 }
 
-static void pm_tmr_timer(ACPIPMTimer *tmr)
+static void pm_tmr_timer(ACPIREGS *ar)
 {
-    PIIX4PMState *s = container_of(tmr, PIIX4PMState, tmr);
+    PIIX4PMState *s = container_of(ar, PIIX4PMState, ar);
     pm_update_sci(s);
 }
 
@@ -116,15 +113,15 @@ static void pm_ioport_write(IORange *ioport, uint64_t addr, unsigned width,
 
     switch(addr) {
     case 0x00:
-        acpi_pm1_evt_write_sts(&s->pm1a, &s->tmr, val);
+        acpi_pm1_evt_write_sts(&s->ar, val);
         pm_update_sci(s);
         break;
     case 0x02:
-        s->pm1a.en = val;
+        s->ar.pm1.evt.en = val;
         pm_update_sci(s);
         break;
     case 0x04:
-        acpi_pm1_cnt_write(&s->pm1a, &s->pm1_cnt, val);
+        acpi_pm1_cnt_write(&s->ar, val);
         break;
     default:
         break;
@@ -141,16 +138,16 @@ static void pm_ioport_read(IORange *ioport, uint64_t addr, unsigned width,
 
     switch(addr) {
     case 0x00:
-        val = acpi_pm1_evt_get_sts(&s->pm1a, s->tmr.overflow_time);
+        val = acpi_pm1_evt_get_sts(&s->ar, s->ar.tmr.overflow_time);
         break;
     case 0x02:
-        val = s->pm1a.en;
+        val = s->ar.pm1.evt.en;
         break;
     case 0x04:
-        val = s->pm1_cnt.cnt;
+        val = s->ar.pm1.cnt.cnt;
         break;
     case 0x08:
-        val = acpi_pm_tmr_get(&s->tmr);
+        val = acpi_pm_tmr_get(&s->ar);
         break;
     default:
         val = 0;
@@ -170,7 +167,7 @@ static void apm_ctrl_changed(uint32_t val, void *arg)
     PIIX4PMState *s = arg;
 
     /* ACPI specs 3.0, 4.7.2.5 */
-    acpi_pm1_cnt_update(&s->pm1_cnt, val == ACPI_ENABLE, val == ACPI_DISABLE);
+    acpi_pm1_cnt_update(&s->ar, val == ACPI_ENABLE, val == ACPI_DISABLE);
 
     if (s->dev.config[0x5b] & (1 << 1)) {
         if (s->smi_irq) {
@@ -258,13 +255,13 @@ static const VMStateDescription vmstate_acpi = {
     .post_load = vmstate_acpi_post_load,
     .fields      = (VMStateField []) {
         VMSTATE_PCI_DEVICE(dev, PIIX4PMState),
-        VMSTATE_UINT16(pm1a.sts, PIIX4PMState),
-        VMSTATE_UINT16(pm1a.en, PIIX4PMState),
-        VMSTATE_UINT16(pm1_cnt.cnt, PIIX4PMState),
+        VMSTATE_UINT16(ar.pm1.evt.sts, PIIX4PMState),
+        VMSTATE_UINT16(ar.pm1.evt.en, PIIX4PMState),
+        VMSTATE_UINT16(ar.pm1.cnt.cnt, PIIX4PMState),
         VMSTATE_STRUCT(apm, PIIX4PMState, 0, vmstate_apm, APMState),
-        VMSTATE_TIMER(tmr.timer, PIIX4PMState),
-        VMSTATE_INT64(tmr.overflow_time, PIIX4PMState),
-        VMSTATE_STRUCT(gpe, PIIX4PMState, 2, vmstate_gpe, ACPIGPE),
+        VMSTATE_TIMER(ar.tmr.timer, PIIX4PMState),
+        VMSTATE_INT64(ar.tmr.overflow_time, PIIX4PMState),
+        VMSTATE_STRUCT(ar.gpe, PIIX4PMState, 2, vmstate_gpe, ACPIGPE),
         VMSTATE_STRUCT(pci0_status, PIIX4PMState, 2, vmstate_pci_status,
                        struct pci_status),
         VMSTATE_END_OF_LIST()
@@ -310,10 +307,9 @@ static void piix4_reset(void *opaque)
 static void piix4_powerdown(void *opaque, int irq, int power_failing)
 {
     PIIX4PMState *s = opaque;
-    ACPIPM1EVT *pm1a = s? &s->pm1a: NULL;
-    ACPIPMTimer *tmr = s? &s->tmr: NULL;
 
-    acpi_pm1_evt_power_down(pm1a, tmr);
+    assert(s != NULL);
+    acpi_pm1_evt_power_down(&s->ar);
 }
 
 static void piix4_pm_machine_ready(Notifier *n, void *opaque)
@@ -361,8 +357,8 @@ static int piix4_pm_initfn(PCIDevice *dev)
     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);
 
-    acpi_pm_tmr_init(&s->tmr, pm_tmr_timer);
-    acpi_gpe_init(&s->gpe, GPE_LEN);
+    acpi_pm_tmr_init(&s->ar, pm_tmr_timer);
+    acpi_gpe_init(&s->ar, GPE_LEN);
 
     qemu_system_powerdown = *qemu_allocate_irqs(piix4_powerdown, s, 1);
 
@@ -387,7 +383,7 @@ 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->pm1_cnt, cmos_s3);
+    acpi_pm1_cnt_init(&s->ar, cmos_s3);
     s->smi_irq = smi_irq;
     s->kvm_enabled = kvm_enabled;
 
@@ -436,7 +432,7 @@ device_init(piix4_pm_register);
 static uint32_t gpe_readb(void *opaque, uint32_t addr)
 {
     PIIX4PMState *s = opaque;
-    uint32_t val = acpi_gpe_ioport_readb(&s->gpe, addr);
+    uint32_t val = acpi_gpe_ioport_readb(&s->ar, addr);
 
     PIIX4_DPRINTF("gpe read %x == %x\n", addr, val);
     return val;
@@ -446,7 +442,7 @@ static void gpe_writeb(void *opaque, uint32_t addr, uint32_t val)
 {
     PIIX4PMState *s = opaque;
 
-    acpi_gpe_ioport_writeb(&s->gpe, addr, val);
+    acpi_gpe_ioport_writeb(&s->ar, addr, val);
     pm_update_sci(s);
 
     PIIX4_DPRINTF("gpe write %x <== %d\n", addr, val);
@@ -531,7 +527,7 @@ static void piix4_acpi_system_hot_add_init(PCIBus *bus, PIIX4PMState *s)
 
     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->gpe, GPE_BASE);
+    acpi_gpe_blk(&s->ar, GPE_BASE);
 
     register_ioport_write(PCI_BASE, 8, 4, pcihotplug_write, pci0_status);
     register_ioport_read(PCI_BASE, 8, 4,  pcihotplug_read, pci0_status);
@@ -547,13 +543,13 @@ static void piix4_acpi_system_hot_add_init(PCIBus *bus, PIIX4PMState *s)
 
 static void enable_device(PIIX4PMState *s, int slot)
 {
-    s->gpe.sts[0] |= PIIX4_PCI_HOTPLUG_STATUS;
+    s->ar.gpe.sts[0] |= PIIX4_PCI_HOTPLUG_STATUS;
     s->pci0_status.up |= (1 << slot);
 }
 
 static void disable_device(PIIX4PMState *s, int slot)
 {
-    s->gpe.sts[0] |= PIIX4_PCI_HOTPLUG_STATUS;
+    s->ar.gpe.sts[0] |= PIIX4_PCI_HOTPLUG_STATUS;
     s->pci0_status.down |= (1 << slot);
 }
 
diff --git a/hw/vt82c686.c b/hw/vt82c686.c
index aa0954f..8370434 100644
--- a/hw/vt82c686.c
+++ b/hw/vt82c686.c
@@ -159,10 +159,8 @@ static void vt82c686b_write_config(PCIDevice * d, uint32_t address,
 
 typedef struct VT686PMState {
     PCIDevice dev;
-    ACPIPM1EVT pm1a;
-    ACPIPM1CNT pm1_cnt;
+    ACPIREGS ar;
     APMState apm;
-    ACPIPMTimer tmr;
     PMSMBus smb;
     uint32_t smb_io_base;
 } VT686PMState;
@@ -179,21 +177,21 @@ static void pm_update_sci(VT686PMState *s)
 {
     int sci_level, pmsts;
 
-    pmsts = acpi_pm1_evt_get_sts(&s->pm1a, s->tmr.overflow_time);
-    sci_level = (((pmsts & s->pm1a.en) &
+    pmsts = acpi_pm1_evt_get_sts(&s->ar, s->ar.tmr.overflow_time);
+    sci_level = (((pmsts & s->ar.pm1.evt.en) &
                   (ACPI_BITMASK_RT_CLOCK_ENABLE |
                    ACPI_BITMASK_POWER_BUTTON_ENABLE |
                    ACPI_BITMASK_GLOBAL_LOCK_ENABLE |
                    ACPI_BITMASK_TIMER_ENABLE)) != 0);
     qemu_set_irq(s->dev.irq[0], sci_level);
     /* schedule a timer interruption if needed */
-    acpi_pm_tmr_update(&s->tmr, (s->pm1a.en & ACPI_BITMASK_TIMER_ENABLE) &&
+    acpi_pm_tmr_update(&s->ar, (s->ar.pm1.evt.en & ACPI_BITMASK_TIMER_ENABLE) &&
                        !(pmsts & ACPI_BITMASK_TIMER_STATUS));
 }
 
-static void pm_tmr_timer(ACPIPMTimer *tmr)
+static void pm_tmr_timer(ACPIREGS *ar)
 {
-    VT686PMState *s = container_of(tmr, VT686PMState, tmr);
+    VT686PMState *s = container_of(ar, VT686PMState, ar);
     pm_update_sci(s);
 }
 
@@ -204,15 +202,15 @@ static void pm_ioport_writew(void *opaque, uint32_t addr, uint32_t val)
     addr &= 0x0f;
     switch (addr) {
     case 0x00:
-        acpi_pm1_evt_write_sts(&s->pm1a, &s->tmr, val);
+        acpi_pm1_evt_write_sts(&s->ar, val);
         pm_update_sci(s);
         break;
     case 0x02:
-        s->pm1a.en = val;
+        s->ar.pm1.evt.en = val;
         pm_update_sci(s);
         break;
     case 0x04:
-        acpi_pm1_cnt_write(&s->pm1a, &s->pm1_cnt, val);
+        acpi_pm1_cnt_write(&s->ar, val);
         break;
     default:
         break;
@@ -228,13 +226,13 @@ static uint32_t pm_ioport_readw(void *opaque, uint32_t addr)
     addr &= 0x0f;
     switch (addr) {
     case 0x00:
-        val = acpi_pm1_evt_get_sts(&s->pm1a, s->tmr.overflow_time);
+        val = acpi_pm1_evt_get_sts(&s->ar, s->ar.tmr.overflow_time);
         break;
     case 0x02:
-        val = s->pm1a.en;
+        val = s->ar.pm1.evt.en;
         break;
     case 0x04:
-        val = s->pm1_cnt.cnt;
+        val = s->ar.pm1.cnt.cnt;
         break;
     default:
         val = 0;
@@ -258,7 +256,7 @@ static uint32_t pm_ioport_readl(void *opaque, uint32_t addr)
     addr &= 0x0f;
     switch (addr) {
     case 0x08:
-        val = acpi_pm_tmr_get(&s->tmr);
+        val = acpi_pm_tmr_get(&s->ar);
         break;
     default:
         val = 0;
@@ -309,12 +307,12 @@ static const VMStateDescription vmstate_acpi = {
     .post_load = vmstate_acpi_post_load,
     .fields      = (VMStateField []) {
         VMSTATE_PCI_DEVICE(dev, VT686PMState),
-        VMSTATE_UINT16(pm1a.sts, VT686PMState),
-        VMSTATE_UINT16(pm1a.en, VT686PMState),
-        VMSTATE_UINT16(pm1_cnt.cnt, VT686PMState),
+        VMSTATE_UINT16(ar.pm1.evt.sts, VT686PMState),
+        VMSTATE_UINT16(ar.pm1.evt.en, VT686PMState),
+        VMSTATE_UINT16(ar.pm1.cnt.cnt, VT686PMState),
         VMSTATE_STRUCT(apm, VT686PMState, 0, vmstate_apm, APMState),
-        VMSTATE_TIMER(tmr.timer, VT686PMState),
-        VMSTATE_INT64(tmr.overflow_time, VT686PMState),
+        VMSTATE_TIMER(ar.tmr.timer, VT686PMState),
+        VMSTATE_INT64(ar.tmr.overflow_time, VT686PMState),
         VMSTATE_END_OF_LIST()
     }
 };
@@ -445,8 +443,8 @@ static int vt82c686b_pm_initfn(PCIDevice *dev)
 
     apm_init(&s->apm, NULL, s);
 
-    acpi_pm_tmr_init(&s->tmr, pm_tmr_timer);
-    acpi_pm1_cnt_init(&s->pm1_cnt, NULL);
+    acpi_pm_tmr_init(&s->ar, pm_tmr_timer);
+    acpi_pm1_cnt_init(&s->ar, NULL);
 
     pm_smbus_init(&s->dev.qdev, &s->smb);
 
