diff --git a/hw/acpi/core.c b/hw/acpi/core.c
index 7467b88e27..7138139d32 100644
--- a/hw/acpi/core.c
+++ b/hw/acpi/core.c
@@ -324,12 +324,13 @@ static void acpi_notify_wakeup(Notifier *notifier, void *data)
             (ACPI_BITMASK_WAKE_STATUS | ACPI_BITMASK_TIMER_STATUS);
         break;
     case QEMU_WAKEUP_REASON_OTHER:
-    default:
         /* ACPI_BITMASK_WAKE_STATUS should be set on resume.
            Pretend that resume was caused by power button */
         ar->pm1.evt.sts |=
             (ACPI_BITMASK_WAKE_STATUS | ACPI_BITMASK_POWER_BUTTON_STATUS);
         break;
+    default:
+        break;
     }
 }
 
diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
index 907792b721..c6042c7e23 100644
--- a/hw/i386/pc_piix.c
+++ b/hw/i386/pc_piix.c
@@ -741,6 +741,7 @@ static QEMUMachine xenfv_machine = {
     .init = pc_xen_hvm_init,
     .max_cpus = HVM_MAX_VCPUS,
     .default_machine_opts = "accel=xen",
+    .hot_add_cpu = pc_hot_add_cpu,
 };
 #endif
 
diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
index e2c6f58d9e..ffc53aa848 100644
--- a/include/sysemu/sysemu.h
+++ b/include/sysemu/sysemu.h
@@ -41,9 +41,11 @@ int vm_stop(RunState state);
 int vm_stop_force_state(RunState state);
 
 typedef enum WakeupReason {
-    QEMU_WAKEUP_REASON_OTHER = 0,
+    /* Always keep QEMU_WAKEUP_REASON_NONE = 0 */
+    QEMU_WAKEUP_REASON_NONE = 0,
     QEMU_WAKEUP_REASON_RTC,
     QEMU_WAKEUP_REASON_PMTIMER,
+    QEMU_WAKEUP_REASON_OTHER,
 } WakeupReason;
 
 void qemu_system_reset_request(void);
diff --git a/vl.c b/vl.c
index 4e709d5c1c..e4113efbaa 100644
--- a/vl.c
+++ b/vl.c
@@ -1718,14 +1718,14 @@ static pid_t shutdown_pid;
 static int powerdown_requested;
 static int debug_requested;
 static int suspend_requested;
-static int wakeup_requested;
+static WakeupReason wakeup_reason;
 static NotifierList powerdown_notifiers =
     NOTIFIER_LIST_INITIALIZER(powerdown_notifiers);
 static NotifierList suspend_notifiers =
     NOTIFIER_LIST_INITIALIZER(suspend_notifiers);
 static NotifierList wakeup_notifiers =
     NOTIFIER_LIST_INITIALIZER(wakeup_notifiers);
-static uint32_t wakeup_reason_mask = ~0;
+static uint32_t wakeup_reason_mask = ~(1 << QEMU_WAKEUP_REASON_NONE);
 static RunState vmstop_requested = RUN_STATE_MAX;
 
 int qemu_shutdown_requested_get(void)
@@ -1775,11 +1775,9 @@ static int qemu_suspend_requested(void)
     return r;
 }
 
-static int qemu_wakeup_requested(void)
+static WakeupReason qemu_wakeup_requested(void)
 {
-    int r = wakeup_requested;
-    wakeup_requested = 0;
-    return r;
+    return wakeup_reason;
 }
 
 static int qemu_powerdown_requested(void)
@@ -1896,8 +1894,7 @@ void qemu_system_wakeup_request(WakeupReason reason)
         return;
     }
     runstate_set(RUN_STATE_RUNNING);
-    notifier_list_notify(&wakeup_notifiers, &reason);
-    wakeup_requested = 1;
+    wakeup_reason = reason;
     qemu_notify_event();
 }
 
@@ -1989,6 +1986,8 @@ static bool main_loop_should_exit(void)
         pause_all_vcpus();
         cpu_synchronize_all_states();
         qemu_system_reset(VMRESET_SILENT);
+        notifier_list_notify(&wakeup_notifiers, &wakeup_reason);
+        wakeup_reason = QEMU_WAKEUP_REASON_NONE;
         resume_all_vcpus();
         monitor_protocol_event(QEVENT_WAKEUP, NULL);
     }
diff --git a/xen-all.c b/xen-all.c
index 839f14f53c..48e881bc29 100644
--- a/xen-all.c
+++ b/xen-all.c
@@ -98,6 +98,7 @@ typedef struct XenIOState {
 
     Notifier exit;
     Notifier suspend;
+    Notifier wakeup;
 } XenIOState;
 
 /* Xen specific function for piix pci */
@@ -613,13 +614,13 @@ static ioreq_t *cpu_get_ioreq(XenIOState *state)
     }
 
     if (port != -1) {
-        for (i = 0; i < smp_cpus; i++) {
+        for (i = 0; i < max_cpus; i++) {
             if (state->ioreq_local_port[i] == port) {
                 break;
             }
         }
 
-        if (i == smp_cpus) {
+        if (i == max_cpus) {
             hw_error("Fatal error while trying to get io event!\n");
         }
 
@@ -1060,6 +1061,11 @@ static void xen_read_physmap(XenIOState *state)
     free(entries);
 }
 
+static void xen_wakeup_notifier(Notifier *notifier, void *data)
+{
+    xc_set_hvm_param(xen_xc, xen_domid, HVM_PARAM_ACPI_S_STATE, 0);
+}
+
 int xen_hvm_init(MemoryRegion **ram_memory)
 {
     int i, rc;
@@ -1089,6 +1095,9 @@ int xen_hvm_init(MemoryRegion **ram_memory)
     state->suspend.notify = xen_suspend_notifier;
     qemu_register_suspend_notifier(&state->suspend);
 
+    state->wakeup.notify = xen_wakeup_notifier;
+    qemu_register_wakeup_notifier(&state->wakeup);
+
     xc_get_hvm_param(xen_xc, xen_domid, HVM_PARAM_IOREQ_PFN, &ioreq_pfn);
     DPRINTF("shared page at pfn %lx\n", ioreq_pfn);
     state->shared_page = xc_map_foreign_range(xen_xc, xen_domid, XC_PAGE_SIZE,
@@ -1106,10 +1115,10 @@ int xen_hvm_init(MemoryRegion **ram_memory)
         hw_error("map buffered IO page returned error %d", errno);
     }
 
-    state->ioreq_local_port = g_malloc0(smp_cpus * sizeof (evtchn_port_t));
+    state->ioreq_local_port = g_malloc0(max_cpus * sizeof (evtchn_port_t));
 
     /* FIXME: how about if we overflow the page here? */
-    for (i = 0; i < smp_cpus; i++) {
+    for (i = 0; i < max_cpus; i++) {
         rc = xc_evtchn_bind_interdomain(state->xce_handle, xen_domid,
                                         xen_vcpu_eport(state->shared_page, i));
         if (rc == -1) {