diff --git a/include/hw/cpu/cortex_mpcore.h b/include/hw/cpu/cortex_mpcore.h
index 387552468c..96da713be9 100644
--- a/include/hw/cpu/cortex_mpcore.h
+++ b/include/hw/cpu/cortex_mpcore.h
@@ -32,6 +32,8 @@
  *    the cluster.
  *  + QOM properties "cpu-has-el3", "cpu-has-el2" which set whether the CPUs
  *    have the exception level features present.
+ *  + QOM property "gic-spi-num" sets the number of GIC Shared Peripheral
+ *    Interrupts.
  */
 #define TYPE_CORTEX_MPCORE_PRIV "cortex_mpcore_priv"
 OBJECT_DECLARE_TYPE(CortexMPPrivState, CortexMPPrivClass, CORTEX_MPCORE_PRIV)
@@ -39,6 +41,8 @@ OBJECT_DECLARE_TYPE(CortexMPPrivState, CortexMPPrivClass, CORTEX_MPCORE_PRIV)
 /**
  * CortexMPPrivClass:
  * @container_size - size of the device's MMIO region
+ * @gic_spi_default - default number of GIC SPIs
+ * @gic_spi_max - maximum number of GIC SPIs
  */
 struct CortexMPPrivClass {
     SysBusDeviceClass parent_class;
@@ -46,6 +50,9 @@ struct CortexMPPrivClass {
     DeviceRealize parent_realize;
 
     uint64_t container_size;
+
+    unsigned gic_spi_default;
+    unsigned gic_spi_max;
 };
 
 struct CortexMPPrivState {
@@ -58,6 +65,8 @@ struct CortexMPPrivState {
 
     bool cpu_has_el3;
     bool cpu_has_el2;
+
+    uint32_t gic_spi_num;
 };
 
 #define TYPE_A9MPCORE_PRIV "a9mpcore_priv"
@@ -66,8 +75,6 @@ OBJECT_DECLARE_SIMPLE_TYPE(A9MPPrivState, A9MPCORE_PRIV)
 struct A9MPPrivState {
     CortexMPPrivState parent_obj;
 
-    uint32_t num_irq;
-
     A9SCUState scu;
     GICState gic;
     A9GTimerState gtimer;
@@ -81,8 +88,6 @@ OBJECT_DECLARE_SIMPLE_TYPE(A15MPPrivState, A15MPCORE_PRIV)
 struct A15MPPrivState {
     CortexMPPrivState parent_obj;
 
-    uint32_t num_irq;
-
     GICState gic;
 };
 
diff --git a/hw/cpu/a15mpcore.c b/hw/cpu/a15mpcore.c
index a16544fdde..195355b589 100644
--- a/hw/cpu/a15mpcore.c
+++ b/hw/cpu/a15mpcore.c
@@ -61,7 +61,7 @@ static void a15mp_priv_realize(DeviceState *dev, Error **errp)
 
     gicdev = DEVICE(&s->gic);
     qdev_prop_set_uint32(gicdev, "num-cpu", c->num_cores);
-    qdev_prop_set_uint32(gicdev, "num-irq", s->num_irq);
+    qdev_prop_set_uint32(gicdev, "num-irq", c->gic_spi_num);
 
     if (!kvm_irqchip_in_kernel()) {
         /* Make the GIC's TZ support match the CPUs. We assume that
@@ -83,14 +83,14 @@ static void a15mp_priv_realize(DeviceState *dev, Error **errp)
     sysbus_pass_irq(sbd, gicsbd);
 
     /* Pass through inbound GPIO lines to the GIC */
-    qdev_init_gpio_in(dev, a15mp_priv_set_irq, s->num_irq - 32);
+    qdev_init_gpio_in(dev, a15mp_priv_set_irq, c->gic_spi_num - 32);
 
     /* Wire the outputs from each CPU's generic timer to the
      * appropriate GIC PPI inputs
      */
     for (i = 0; i < c->num_cores; i++) {
         DeviceState *cpudev = DEVICE(qemu_get_cpu(i));
-        int ppibase = s->num_irq - 32 + i * 32;
+        int ppibase = c->gic_spi_num - 32 + i * 32;
         int irq;
         /* Mapping from the output timer irq lines from the CPU to the
          * GIC PPI inputs used on the A15:
@@ -142,17 +142,6 @@ static void a15mp_priv_realize(DeviceState *dev, Error **errp)
     }
 }
 
-static Property a15mp_priv_properties[] = {
-    /* The Cortex-A15MP may have anything from 0 to 224 external interrupt
-     * IRQ lines (with another 32 internal). We default to 128+32, which
-     * is the number provided by the Cortex-A15MP test chip in the
-     * Versatile Express A15 development board.
-     * Other boards may differ and should set this property appropriately.
-     */
-    DEFINE_PROP_UINT32("num-irq", A15MPPrivState, num_irq, 160),
-    DEFINE_PROP_END_OF_LIST(),
-};
-
 static void a15mp_priv_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -160,9 +149,18 @@ static void a15mp_priv_class_init(ObjectClass *klass, void *data)
 
     cc->container_size = 0x8000;
 
+    /*
+     * The Cortex-A15MP may have anything from 0 to 224 external interrupt
+     * IRQ lines (with another 32 internal). We default to 128+32, which
+     * is the number provided by the Cortex-A15MP test chip in the
+     * Versatile Express A15 development board.
+     * Other boards may differ and should set this property appropriately.
+     */
+    cc->gic_spi_default = 160;
+    cc->gic_spi_max = 224;
+
     device_class_set_parent_realize(dc, a15mp_priv_realize,
                                     &cc->parent_realize);
-    device_class_set_props(dc, a15mp_priv_properties);
     /* We currently have no saveable state */
 }
 
diff --git a/hw/cpu/a9mpcore.c b/hw/cpu/a9mpcore.c
index 54949314f8..72621bce64 100644
--- a/hw/cpu/a9mpcore.c
+++ b/hw/cpu/a9mpcore.c
@@ -78,7 +78,7 @@ static void a9mp_priv_realize(DeviceState *dev, Error **errp)
 
     gicdev = DEVICE(&s->gic);
     qdev_prop_set_uint32(gicdev, "num-cpu", c->num_cores);
-    qdev_prop_set_uint32(gicdev, "num-irq", s->num_irq);
+    qdev_prop_set_uint32(gicdev, "num-irq", c->gic_spi_num);
     qdev_prop_set_uint32(gicdev, "num-priority-bits",
                          A9_GIC_NUM_PRIORITY_BITS);
 
@@ -96,7 +96,7 @@ static void a9mp_priv_realize(DeviceState *dev, Error **errp)
     sysbus_pass_irq(sbd, gicbusdev);
 
     /* Pass through inbound GPIO lines to the GIC */
-    qdev_init_gpio_in(dev, a9mp_priv_set_irq, s->num_irq - 32);
+    qdev_init_gpio_in(dev, a9mp_priv_set_irq, c->gic_spi_num - 32);
 
     gtimerdev = DEVICE(&s->gtimer);
     qdev_prop_set_uint32(gtimerdev, "num-cpu", c->num_cores);
@@ -150,7 +150,7 @@ static void a9mp_priv_realize(DeviceState *dev, Error **errp)
      * timer is PPI 29 and the watchdog PPI 30.
      */
     for (unsigned i = 0; i < c->num_cores; i++) {
-        int ppibase = (s->num_irq - 32) + i * 32;
+        int ppibase = (c->gic_spi_num - 32) + i * 32;
         sysbus_connect_irq(gtimerbusdev, i,
                            qdev_get_gpio_in(gicdev, ppibase + 27));
         sysbus_connect_irq(mptimerbusdev, i,
@@ -160,17 +160,6 @@ static void a9mp_priv_realize(DeviceState *dev, Error **errp)
     }
 }
 
-static Property a9mp_priv_properties[] = {
-    /* The Cortex-A9MP may have anything from 0 to 224 external interrupt
-     * IRQ lines (with another 32 internal). We default to 64+32, which
-     * is the number provided by the Cortex-A9MP test chip in the
-     * Realview PBX-A9 and Versatile Express A9 development boards.
-     * Other boards may differ and should set this property appropriately.
-     */
-    DEFINE_PROP_UINT32("num-irq", A9MPPrivState, num_irq, 96),
-    DEFINE_PROP_END_OF_LIST(),
-};
-
 static void a9mp_priv_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
@@ -178,8 +167,17 @@ static void a9mp_priv_class_init(ObjectClass *klass, void *data)
 
     cc->container_size = 0x2000;
 
+    /*
+     * The Cortex-A9MP may have anything from 0 to 224 external interrupt
+     * IRQ lines (with another 32 internal). We default to 64+32, which
+     * is the number provided by the Cortex-A9MP test chip in the
+     * Realview PBX-A9 and Versatile Express A9 development boards.
+     * Other boards may differ and should set this property appropriately.
+     */
+    cc->gic_spi_default = 96;
+    cc->gic_spi_max = 224;
+
     device_class_set_parent_realize(dc, a9mp_priv_realize, &cc->parent_realize);
-    device_class_set_props(dc, a9mp_priv_properties);
 }
 
 static const TypeInfo a9mp_types[] = {
diff --git a/hw/cpu/cortex_mpcore.c b/hw/cpu/cortex_mpcore.c
index 549b81f708..dee40a7bf2 100644
--- a/hw/cpu/cortex_mpcore.c
+++ b/hw/cpu/cortex_mpcore.c
@@ -21,6 +21,8 @@ static void cortex_mpcore_priv_instance_init(Object *obj)
     memory_region_init(&s->container, obj,
                        "mpcore-priv-container", k->container_size);
     sysbus_init_mmio(sbd, &s->container);
+
+    s->gic_spi_num = k->gic_spi_default;
 }
 
 static Property cortex_mpcore_priv_properties[] = {
@@ -30,6 +32,9 @@ static Property cortex_mpcore_priv_properties[] = {
     DEFINE_PROP_BOOL("cpu-has-el3", CortexMPPrivState, cpu_has_el3, true),
     DEFINE_PROP_BOOL("cpu-has-el2", CortexMPPrivState, cpu_has_el2, false),
 
+    DEFINE_PROP_UINT32("gic-spi-num", CortexMPPrivState, gic_spi_num, 0),
+    DEFINE_PROP_UINT32("num-irq", CortexMPPrivState, gic_spi_num, 0), /* alias */
+
     DEFINE_PROP_END_OF_LIST(),
 };
 
