diff --git a/hw/pci-host/apb.c b/hw/pci-host/apb.c
index 268100e..f092780c 100644
--- a/hw/pci-host/apb.c
+++ b/hw/pci-host/apb.c
@@ -700,7 +700,7 @@ static void pci_pbm_init(Object *obj)
     for (i = 0; i < 32; i++) {
         s->obio_irq_map[i] = ((0x1f << 6) | 0x20) + i;
     }
-    s->pbm_irqs = qemu_allocate_irqs(pci_apb_set_irq, s, MAX_IVEC);
+    qdev_init_gpio_in_named(DEVICE(s), pci_apb_set_irq, "pbm-irq", MAX_IVEC);
     qdev_init_gpio_out_named(DEVICE(s), s->ivec_irqs, "ivec-irq", MAX_IVEC);
     s->irq_request = NO_IRQ_REQUEST;
     s->pci_irq_in = 0ULL;
diff --git a/hw/sparc64/sun4u.c b/hw/sparc64/sun4u.c
index 0a30fb8..da386d3 100644
--- a/hw/sparc64/sun4u.c
+++ b/hw/sparc64/sun4u.c
@@ -86,6 +86,7 @@ typedef struct EbusState {
     PCIDevice parent_obj;
 
     ISABus *isa_bus;
+    qemu_irq isa_bus_irqs[16];
     uint64_t console_serial_base;
     MemoryRegion bar0;
     MemoryRegion bar1;
@@ -211,23 +212,15 @@ typedef struct ResetData {
     uint64_t prom_addr;
 } ResetData;
 
-static void isa_irq_handler(void *opaque, int n, int level)
+static void ebus_isa_irq_handler(void *opaque, int n, int level)
 {
-    static const int isa_irq_to_ivec[16] = {
-        [1] = 0x29, /* keyboard */
-        [4] = 0x2b, /* serial */
-        [6] = 0x27, /* floppy */
-        [7] = 0x22, /* parallel */
-        [12] = 0x2a, /* mouse */
-    };
-    qemu_irq *irqs = opaque;
-    int ivec;
-
-    assert(n < ARRAY_SIZE(isa_irq_to_ivec));
-    ivec = isa_irq_to_ivec[n];
-    EBUS_DPRINTF("Set ISA IRQ %d level %d -> ivec 0x%x\n", n, level, ivec);
-    if (ivec) {
-        qemu_set_irq(irqs[ivec], level);
+    EbusState *s = EBUS(opaque);
+    qemu_irq irq = s->isa_bus_irqs[n];
+
+    /* Pass ISA bus IRQs onto their gpio equivalent */
+    EBUS_DPRINTF("Set ISA IRQ %d level %d\n", n, level);
+    if (irq) {
+        qemu_set_irq(irq, level);
     }
 }
 
@@ -235,7 +228,6 @@ static void isa_irq_handler(void *opaque, int n, int level)
 static void ebus_realize(PCIDevice *pci_dev, Error **errp)
 {
     EbusState *s = EBUS(pci_dev);
-    APBState *apb;
     DeviceState *dev;
     qemu_irq *isa_irq;
     DriveInfo *fd[MAX_FD];
@@ -248,14 +240,10 @@ static void ebus_realize(PCIDevice *pci_dev, Error **errp)
         return;
     }
 
-    apb = APB_DEVICE(object_resolve_path_type("", TYPE_APB, NULL));
-    if (!apb) {
-        error_setg(errp, "unable to locate APB PCI host bridge");
-        return;
-    }
-
-    isa_irq = qemu_allocate_irqs(isa_irq_handler, apb->pbm_irqs, 16);
+    /* ISA bus */
+    isa_irq = qemu_allocate_irqs(ebus_isa_irq_handler, s, 16);
     isa_bus_irqs(s->isa_bus, isa_irq);
+    qdev_init_gpio_out_named(DEVICE(s), s->isa_bus_irqs, "isa-irq", 16);
 
     /* Serial ports */
     i = 0;
@@ -530,6 +518,18 @@ static void sun4uv_init(MemoryRegion *address_space_mem,
                          hwdef->console_serial_base);
     qdev_init_nofail(DEVICE(ebus));
 
+    /* Wire up "well-known" ISA IRQs to APB legacy obio IRQs */
+    qdev_connect_gpio_out_named(DEVICE(ebus), "isa-irq", 7,
+        qdev_get_gpio_in_named(DEVICE(apb), "pbm-irq", OBIO_LPT_IRQ));
+    qdev_connect_gpio_out_named(DEVICE(ebus), "isa-irq", 6,
+        qdev_get_gpio_in_named(DEVICE(apb), "pbm-irq", OBIO_FDD_IRQ));
+    qdev_connect_gpio_out_named(DEVICE(ebus), "isa-irq", 1,
+        qdev_get_gpio_in_named(DEVICE(apb), "pbm-irq", OBIO_KBD_IRQ));
+    qdev_connect_gpio_out_named(DEVICE(ebus), "isa-irq", 12,
+        qdev_get_gpio_in_named(DEVICE(apb), "pbm-irq", OBIO_MSE_IRQ));
+    qdev_connect_gpio_out_named(DEVICE(ebus), "isa-irq", 4,
+        qdev_get_gpio_in_named(DEVICE(apb), "pbm-irq", OBIO_SER_IRQ));
+
     pci_dev = pci_create_simple(pci_busA, PCI_DEVFN(2, 0), "VGA");
 
     memset(&macaddr, 0, sizeof(MACAddr));
diff --git a/include/hw/pci-host/apb.h b/include/hw/pci-host/apb.h
index dd49437..09ebd53 100644
--- a/include/hw/pci-host/apb.h
+++ b/include/hw/pci-host/apb.h
@@ -52,6 +52,13 @@ typedef struct IOMMUState {
 
 #define MAX_IVEC 0x40
 
+/* OBIO IVEC IRQs */
+#define OBIO_LPT_IRQ         0x22
+#define OBIO_FDD_IRQ         0x27
+#define OBIO_KBD_IRQ         0x29
+#define OBIO_MSE_IRQ         0x2a
+#define OBIO_SER_IRQ         0x2b
+
 #define TYPE_APB "pbm"
 
 #define APB_DEVICE(obj) \
@@ -76,7 +83,6 @@ typedef struct APBState {
     uint32_t pci_irq_map[8];
     uint32_t pci_err_irq_map[4];
     uint32_t obio_irq_map[32];
-    qemu_irq *pbm_irqs;
     qemu_irq ivec_irqs[MAX_IVEC];
     unsigned int irq_request;
     uint32_t reset_control;
