Merge remote-tracking branch 'remotes/pmaydell/tags/pull-target-arm-20180510' into staging

target-arm queue:
 * hw/arm/iotkit.c: fix minor memory leak
 * softfloat: fix wrong-exception-flags bug for multiply-add corner case
 * arm: isolate and clean up DTB generation
 * implement Arm v8.1-Atomics extension
 * Fix some bugs and missing instructions in the v8.2-FP16 extension

# gpg: Signature made Thu 10 May 2018 18:44:34 BST
# gpg:                using RSA key 3C2525ED14360CDE
# gpg: Good signature from "Peter Maydell <peter.maydell@linaro.org>"
# gpg:                 aka "Peter Maydell <pmaydell@gmail.com>"
# gpg:                 aka "Peter Maydell <pmaydell@chiark.greenend.org.uk>"
# Primary key fingerprint: E1A5 C593 CD41 9DE2 8E83  15CF 3C25 25ED 1436 0CDE

* remotes/pmaydell/tags/pull-target-arm-20180510: (21 commits)
  target/arm: Clear SVE high bits for FMOV
  target/arm: Fix float16 to/from int16
  target/arm: Implement vector shifted FCVT for fp16
  target/arm: Implement vector shifted SCVF/UCVF for fp16
  target/arm: Enable ARM_FEATURE_V8_ATOMICS for user-only
  target/arm: Implement CAS and CASP
  target/arm: Fill in disas_ldst_atomic
  target/arm: Introduce ARM_FEATURE_V8_ATOMICS and initial decode
  target/riscv: Use new atomic min/max expanders
  tcg: Use GEN_ATOMIC_HELPER_FN for opposite endian atomic add
  tcg: Introduce atomic helpers for integer min/max
  target/xtensa: Use new min/max expanders
  target/arm: Use new min/max expanders
  tcg: Introduce helpers for integer min/max
  atomic.h: Work around gcc spurious "unused value" warning
  make sure that we aren't overwriting mc->get_hotplug_handler by accident
  arm/boot: split load_dtb() from arm_load_kernel()
  platform-bus-device: use device plug callback instead of machine_done notifier
  pc: simplify MachineClass::get_hotplug_handler handling
  softfloat: Handle default NaN mode after pickNaNMulAdd, not before
  ...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

# Conflicts:
#	target/riscv/translate.c

11 files changed, 149 insertions, 197 deletions

diff --git a/hw/arm/boot.c b/hw/arm/boot.c
index 1e2be20..9496f33 100644
--- a/hw/arm/boot.c
+++ b/hw/arm/boot.c
@@ -36,8 +36,8 @@
 #define ARM64_TEXT_OFFSET_OFFSET    8
 #define ARM64_MAGIC_OFFSET          56
 
-static AddressSpace *arm_boot_address_space(ARMCPU *cpu,
-                                            const struct arm_boot_info *info)
+AddressSpace *arm_boot_address_space(ARMCPU *cpu,
+                                     const struct arm_boot_info *info)
 {
     /* Return the address space to use for bootloader reads and writes.
      * We prefer the secure address space if the CPU has it and we're
@@ -486,29 +486,8 @@ static void fdt_add_psci_node(void *fdt)
     qemu_fdt_setprop_cell(fdt, "/psci", "migrate", migrate_fn);
 }
 
-/**
- * load_dtb() - load a device tree binary image into memory
- * @addr:       the address to load the image at
- * @binfo:      struct describing the boot environment
- * @addr_limit: upper limit of the available memory area at @addr
- * @as:         address space to load image to
- *
- * Load a device tree supplied by the machine or by the user  with the
- * '-dtb' command line option, and put it at offset @addr in target
- * memory.
- *
- * If @addr_limit contains a meaningful value (i.e., it is strictly greater
- * than @addr), the device tree is only loaded if its size does not exceed
- * the limit.
- *
- * Returns: the size of the device tree image on success,
- *          0 if the image size exceeds the limit,
- *          -1 on errors.
- *
- * Note: Must not be called unless have_dtb(binfo) is true.
- */
-static int load_dtb(hwaddr addr, const struct arm_boot_info *binfo,
-                    hwaddr addr_limit, AddressSpace *as)
+int arm_load_dtb(hwaddr addr, const struct arm_boot_info *binfo,
+                 hwaddr addr_limit, AddressSpace *as)
 {
     void *fdt = NULL;
     int size, rc;
@@ -935,7 +914,7 @@ static uint64_t load_aarch64_image(const char *filename, hwaddr mem_base,
     return size;
 }
 
-static void arm_load_kernel_notify(Notifier *notifier, void *data)
+void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
 {
     CPUState *cs;
     int kernel_size;
@@ -945,11 +924,6 @@ static void arm_load_kernel_notify(Notifier *notifier, void *data)
     int elf_machine;
     hwaddr entry;
     static const ARMInsnFixup *primary_loader;
-    ArmLoadKernelNotifier *n = DO_UPCAST(ArmLoadKernelNotifier,
-                                         notifier, notifier);
-    ARMCPU *cpu = n->cpu;
-    struct arm_boot_info *info =
-        container_of(n, struct arm_boot_info, load_kernel_notifier);
     AddressSpace *as = arm_boot_address_space(cpu, info);
 
     /* The board code is not supposed to set secure_board_setup unless
@@ -959,6 +933,7 @@ static void arm_load_kernel_notify(Notifier *notifier, void *data)
     assert(!(info->secure_board_setup && kvm_enabled()));
 
     info->dtb_filename = qemu_opt_get(qemu_get_machine_opts(), "dtb");
+    info->dtb_limit = 0;
 
     /* Load the kernel.  */
     if (!info->kernel_filename || info->firmware_loaded) {
@@ -968,9 +943,7 @@ static void arm_load_kernel_notify(Notifier *notifier, void *data)
              * the kernel is supposed to be loaded by the bootloader), copy the
              * DTB to the base of RAM for the bootloader to pick up.
              */
-            if (load_dtb(info->loader_start, info, 0, as) < 0) {
-                exit(1);
-            }
+            info->dtb_start = info->loader_start;
         }
 
         if (info->kernel_filename) {
@@ -1050,15 +1023,14 @@ static void arm_load_kernel_notify(Notifier *notifier, void *data)
          */
         if (elf_low_addr > info->loader_start
             || elf_high_addr < info->loader_start) {
-            /* Pass elf_low_addr as address limit to load_dtb if it may be
+            /* Set elf_low_addr as address limit for arm_load_dtb if it may be
              * pointing into RAM, otherwise pass '0' (no limit)
              */
             if (elf_low_addr < info->loader_start) {
                 elf_low_addr = 0;
             }
-            if (load_dtb(info->loader_start, info, elf_low_addr, as) < 0) {
-                exit(1);
-            }
+            info->dtb_start = info->loader_start;
+            info->dtb_limit = elf_low_addr;
         }
     }
     entry = elf_entry;
@@ -1116,7 +1088,6 @@ static void arm_load_kernel_notify(Notifier *notifier, void *data)
          */
         if (have_dtb(info)) {
             hwaddr align;
-            hwaddr dtb_start;
 
             if (elf_machine == EM_AARCH64) {
                 /*
@@ -1136,11 +1107,9 @@ static void arm_load_kernel_notify(Notifier *notifier, void *data)
             }
 
             /* Place the DTB after the initrd in memory with alignment. */
-            dtb_start = QEMU_ALIGN_UP(info->initrd_start + initrd_size, align);
-            if (load_dtb(dtb_start, info, 0, as) < 0) {
-                exit(1);
-            }
-            fixupcontext[FIXUP_ARGPTR] = dtb_start;
+            info->dtb_start = QEMU_ALIGN_UP(info->initrd_start + initrd_size,
+                                           align);
+            fixupcontext[FIXUP_ARGPTR] = info->dtb_start;
         } else {
             fixupcontext[FIXUP_ARGPTR] = info->loader_start + KERNEL_ARGS_ADDR;
             if (info->ram_size >= (1ULL << 32)) {
@@ -1173,15 +1142,6 @@ static void arm_load_kernel_notify(Notifier *notifier, void *data)
     for (cs = first_cpu; cs; cs = CPU_NEXT(cs)) {
         ARM_CPU(cs)->env.boot_info = info;
     }
-}
-
-void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
-{
-    CPUState *cs;
-
-    info->load_kernel_notifier.cpu = cpu;
-    info->load_kernel_notifier.notifier.notify = arm_load_kernel_notify;
-    qemu_add_machine_init_done_notifier(&info->load_kernel_notifier.notifier);
 
     /* CPU objects (unlike devices) are not automatically reset on system
      * reset, so we must always register a handler to do so. If we're
@@ -1191,6 +1151,12 @@ void arm_load_kernel(ARMCPU *cpu, struct arm_boot_info *info)
     for (cs = first_cpu; cs; cs = CPU_NEXT(cs)) {
         qemu_register_reset(do_cpu_reset, ARM_CPU(cs));
     }
+
+    if (!info->skip_dtb_autoload && have_dtb(info)) {
+        if (arm_load_dtb(info->dtb_start, info, info->dtb_limit, as) < 0) {
+            exit(1);
+        }
+    }
 }
 
 static const TypeInfo arm_linux_boot_if_info = {
diff --git a/hw/arm/iotkit.c b/hw/arm/iotkit.c
index c5f0a5b..234185e 100644
--- a/hw/arm/iotkit.c
+++ b/hw/arm/iotkit.c
@@ -517,6 +517,7 @@ static void iotkit_realize(DeviceState *dev, Error **errp)
                               qdev_get_gpio_in(DEVICE(&s->ppc_irq_orgate), i));
         qdev_connect_gpio_out_named(DEVICE(ppc), "irq", 0,
                                     qdev_get_gpio_in(devs, 0));
+        g_free(gpioname);
     }
 
     iotkit_forward_sec_resp_cfg(s);
diff --git a/hw/arm/sysbus-fdt.c b/hw/arm/sysbus-fdt.c
index d68e3dc..e4c492e 100644
--- a/hw/arm/sysbus-fdt.c
+++ b/hw/arm/sysbus-fdt.c
@@ -49,15 +49,6 @@ typedef struct PlatformBusFDTData {
     PlatformBusDevice *pbus;
 } PlatformBusFDTData;
 
-/*
- * struct used when calling the machine init done notifier
- * that constructs the fdt nodes of platform bus devices
- */
-typedef struct PlatformBusFDTNotifierParams {
-    Notifier notifier;
-    ARMPlatformBusFDTParams *fdt_params;
-} PlatformBusFDTNotifierParams;
-
 /* struct that associates a device type name and a node creation function */
 typedef struct NodeCreationPair {
     const char *typename;
@@ -453,42 +444,17 @@ static void add_fdt_node(SysBusDevice *sbdev, void *opaque)
     exit(1);
 }
 
-/**
- * add_all_platform_bus_fdt_nodes - create all the platform bus nodes
- *
- * builds the parent platform bus node and all the nodes of dynamic
- * sysbus devices attached to it.
- */
-static void add_all_platform_bus_fdt_nodes(ARMPlatformBusFDTParams *fdt_params)
+void platform_bus_add_all_fdt_nodes(void *fdt, const char *intc, hwaddr addr,
+                                    hwaddr bus_size, int irq_start)
 {
     const char platcomp[] = "qemu,platform\0simple-bus";
     PlatformBusDevice *pbus;
     DeviceState *dev;
     gchar *node;
-    uint64_t addr, size;
-    int irq_start, dtb_size;
-    struct arm_boot_info *info = fdt_params->binfo;
-    const ARMPlatformBusSystemParams *params = fdt_params->system_params;
-    const char *intc = fdt_params->intc;
-    void *fdt = info->get_dtb(info, &dtb_size);
-
-    /*
-     * If the user provided a dtb, we assume the dynamic sysbus nodes
-     * already are integrated there. This corresponds to a use case where
-     * the dynamic sysbus nodes are complex and their generation is not yet
-     * supported. In that case the user can take charge of the guest dt
-     * while qemu takes charge of the qom stuff.
-     */
-    if (info->dtb_filename) {
-        return;
-    }
 
     assert(fdt);
 
-    node = g_strdup_printf("/platform@%"PRIx64, params->platform_bus_base);
-    addr = params->platform_bus_base;
-    size = params->platform_bus_size;
-    irq_start = params->platform_bus_first_irq;
+    node = g_strdup_printf("/platform@%"PRIx64, addr);
 
     /* Create a /platform node that we can put all devices into */
     qemu_fdt_add_subnode(fdt, node);
@@ -499,16 +465,13 @@ static void add_all_platform_bus_fdt_nodes(ARMPlatformBusFDTParams *fdt_params)
      */
     qemu_fdt_setprop_cells(fdt, node, "#size-cells", 1);
     qemu_fdt_setprop_cells(fdt, node, "#address-cells", 1);
-    qemu_fdt_setprop_cells(fdt, node, "ranges", 0, addr >> 32, addr, size);
+    qemu_fdt_setprop_cells(fdt, node, "ranges", 0, addr >> 32, addr, bus_size);
 
     qemu_fdt_setprop_phandle(fdt, node, "interrupt-parent", intc);
 
     dev = qdev_find_recursive(sysbus_get_default(), TYPE_PLATFORM_BUS_DEVICE);
     pbus = PLATFORM_BUS_DEVICE(dev);
 
-    /* We can only create dt nodes for dynamic devices when they're ready */
-    assert(pbus->done_gathering);
-
     PlatformBusFDTData data = {
         .fdt = fdt,
         .irq_start = irq_start,
@@ -521,22 +484,3 @@ static void add_all_platform_bus_fdt_nodes(ARMPlatformBusFDTParams *fdt_params)
 
     g_free(node);
 }
-
-static void platform_bus_fdt_notify(Notifier *notifier, void *data)
-{
-    PlatformBusFDTNotifierParams *p = DO_UPCAST(PlatformBusFDTNotifierParams,
-                                                notifier, notifier);
-
-    add_all_platform_bus_fdt_nodes(p->fdt_params);
-    g_free(p->fdt_params);
-    g_free(p);
-}
-
-void arm_register_platform_bus_fdt_creator(ARMPlatformBusFDTParams *fdt_params)
-{
-    PlatformBusFDTNotifierParams *p = g_new(PlatformBusFDTNotifierParams, 1);
-
-    p->fdt_params = fdt_params;
-    p->notifier.notify = platform_bus_fdt_notify;
-    qemu_add_machine_init_done_notifier(&p->notifier);
-}
diff --git a/hw/arm/virt.c b/hw/arm/virt.c
index 11b9f59..a3a28e2 100644
--- a/hw/arm/virt.c
+++ b/hw/arm/virt.c
@@ -94,8 +94,6 @@
 
 #define PLATFORM_BUS_NUM_IRQS 64
 
-static ARMPlatformBusSystemParams platform_bus_params;
-
 /* RAM limit in GB. Since VIRT_MEM starts at the 1GB mark, this means
  * RAM can go up to the 256GB mark, leaving 256GB of the physical
  * address space unallocated and free for future use between 256G and 512G.
@@ -1126,39 +1124,23 @@ static void create_platform_bus(VirtMachineState *vms, qemu_irq *pic)
     DeviceState *dev;
     SysBusDevice *s;
     int i;
-    ARMPlatformBusFDTParams *fdt_params = g_new(ARMPlatformBusFDTParams, 1);
     MemoryRegion *sysmem = get_system_memory();
 
-    platform_bus_params.platform_bus_base = vms->memmap[VIRT_PLATFORM_BUS].base;
-    platform_bus_params.platform_bus_size = vms->memmap[VIRT_PLATFORM_BUS].size;
-    platform_bus_params.platform_bus_first_irq = vms->irqmap[VIRT_PLATFORM_BUS];
-    platform_bus_params.platform_bus_num_irqs = PLATFORM_BUS_NUM_IRQS;
-
-    fdt_params->system_params = &platform_bus_params;
-    fdt_params->binfo = &vms->bootinfo;
-    fdt_params->intc = "/intc";
-    /*
-     * register a machine init done notifier that creates the device tree
-     * nodes of the platform bus and its children dynamic sysbus devices
-     */
-    arm_register_platform_bus_fdt_creator(fdt_params);
-
     dev = qdev_create(NULL, TYPE_PLATFORM_BUS_DEVICE);
     dev->id = TYPE_PLATFORM_BUS_DEVICE;
-    qdev_prop_set_uint32(dev, "num_irqs",
-        platform_bus_params.platform_bus_num_irqs);
-    qdev_prop_set_uint32(dev, "mmio_size",
-        platform_bus_params.platform_bus_size);
+    qdev_prop_set_uint32(dev, "num_irqs", PLATFORM_BUS_NUM_IRQS);
+    qdev_prop_set_uint32(dev, "mmio_size", vms->memmap[VIRT_PLATFORM_BUS].size);
     qdev_init_nofail(dev);
-    s = SYS_BUS_DEVICE(dev);
+    vms->platform_bus_dev = dev;
 
-    for (i = 0; i < platform_bus_params.platform_bus_num_irqs; i++) {
-        int irqn = platform_bus_params.platform_bus_first_irq + i;
+    s = SYS_BUS_DEVICE(dev);
+    for (i = 0; i < PLATFORM_BUS_NUM_IRQS; i++) {
+        int irqn = vms->irqmap[VIRT_PLATFORM_BUS] + i;
         sysbus_connect_irq(s, i, pic[irqn]);
     }
 
     memory_region_add_subregion(sysmem,
-                                platform_bus_params.platform_bus_base,
+                                vms->memmap[VIRT_PLATFORM_BUS].base,
                                 sysbus_mmio_get_region(s, 0));
 }
 
@@ -1229,6 +1211,26 @@ void virt_machine_done(Notifier *notifier, void *data)
 {
     VirtMachineState *vms = container_of(notifier, VirtMachineState,
                                          machine_done);
+    ARMCPU *cpu = ARM_CPU(first_cpu);
+    struct arm_boot_info *info = &vms->bootinfo;
+    AddressSpace *as = arm_boot_address_space(cpu, info);
+
+    /*
+     * If the user provided a dtb, we assume the dynamic sysbus nodes
+     * already are integrated there. This corresponds to a use case where
+     * the dynamic sysbus nodes are complex and their generation is not yet
+     * supported. In that case the user can take charge of the guest dt
+     * while qemu takes charge of the qom stuff.
+     */
+    if (info->dtb_filename == NULL) {
+        platform_bus_add_all_fdt_nodes(vms->fdt, "/intc",
+                                       vms->memmap[VIRT_PLATFORM_BUS].base,
+                                       vms->memmap[VIRT_PLATFORM_BUS].size,
+                                       vms->irqmap[VIRT_PLATFORM_BUS]);
+    }
+    if (arm_load_dtb(info->dtb_start, info, info->dtb_limit, as) < 0) {
+        exit(1);
+    }
 
     virt_acpi_setup(vms);
     virt_build_smbios(vms);
@@ -1456,8 +1458,7 @@ static void machvirt_init(MachineState *machine)
     vms->fw_cfg = create_fw_cfg(vms, &address_space_memory);
     rom_set_fw(vms->fw_cfg);
 
-    vms->machine_done.notify = virt_machine_done;
-    qemu_add_machine_init_done_notifier(&vms->machine_done);
+    create_platform_bus(vms, pic);
 
     vms->bootinfo.ram_size = machine->ram_size;
     vms->bootinfo.kernel_filename = machine->kernel_filename;
@@ -1467,16 +1468,12 @@ static void machvirt_init(MachineState *machine)
     vms->bootinfo.board_id = -1;
     vms->bootinfo.loader_start = vms->memmap[VIRT_MEM].base;
     vms->bootinfo.get_dtb = machvirt_dtb;
+    vms->bootinfo.skip_dtb_autoload = true;
     vms->bootinfo.firmware_loaded = firmware_loaded;
     arm_load_kernel(ARM_CPU(first_cpu), &vms->bootinfo);
 
-    /*
-     * arm_load_kernel machine init done notifier registration must
-     * happen before the platform_bus_create call. In this latter,
-     * another notifier is registered which adds platform bus nodes.
-     * Notifiers are executed in registration reverse order.
-     */
-    create_platform_bus(vms, pic);
+    vms->machine_done.notify = virt_machine_done;
+    qemu_add_machine_init_done_notifier(&vms->machine_done);
 }
 
 static bool virt_get_secure(Object *obj, Error **errp)
@@ -1627,9 +1624,33 @@ static const CPUArchIdList *virt_possible_cpu_arch_ids(MachineState *ms)
     return ms->possible_cpus;
 }
 
+static void virt_machine_device_plug_cb(HotplugHandler *hotplug_dev,
+                                        DeviceState *dev, Error **errp)
+{
+    VirtMachineState *vms = VIRT_MACHINE(hotplug_dev);
+
+    if (vms->platform_bus_dev) {
+        if (object_dynamic_cast(OBJECT(dev), TYPE_SYS_BUS_DEVICE)) {
+            platform_bus_link_device(PLATFORM_BUS_DEVICE(vms->platform_bus_dev),
+                                     SYS_BUS_DEVICE(dev));
+        }
+    }
+}
+
+static HotplugHandler *virt_machine_get_hotplug_handler(MachineState *machine,
+                                                        DeviceState *dev)
+{
+    if (object_dynamic_cast(OBJECT(dev), TYPE_SYS_BUS_DEVICE)) {
+        return HOTPLUG_HANDLER(machine);
+    }
+
+    return NULL;
+}
+
 static void virt_machine_class_init(ObjectClass *oc, void *data)
 {
     MachineClass *mc = MACHINE_CLASS(oc);
+    HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(oc);
 
     mc->init = machvirt_init;
     /* Start max_cpus at the maximum QEMU supports. We'll further restrict
@@ -1648,6 +1669,9 @@ static void virt_machine_class_init(ObjectClass *oc, void *data)
     mc->cpu_index_to_instance_props = virt_cpu_index_to_props;
     mc->default_cpu_type = ARM_CPU_TYPE_NAME("cortex-a15");
     mc->get_default_cpu_node_id = virt_get_default_cpu_node_id;
+    assert(!mc->get_hotplug_handler);
+    mc->get_hotplug_handler = virt_machine_get_hotplug_handler;
+    hc->plug = virt_machine_device_plug_cb;
 }
 
 static const TypeInfo virt_machine_info = {
@@ -1657,6 +1681,10 @@ static const TypeInfo virt_machine_info = {
     .instance_size = sizeof(VirtMachineState),
     .class_size    = sizeof(VirtMachineClass),
     .class_init    = virt_machine_class_init,
+    .interfaces = (InterfaceInfo[]) {
+         { TYPE_HOTPLUG_HANDLER },
+         { }
+    },
 };
 
 static void machvirt_machine_init(void)
diff --git a/hw/core/platform-bus.c b/hw/core/platform-bus.c
index 33d32fb..807cb5c 100644
--- a/hw/core/platform-bus.c
+++ b/hw/core/platform-bus.c
@@ -103,7 +103,6 @@ static void plaform_bus_refresh_irqs(PlatformBusDevice *pbus)
 {
     bitmap_zero(pbus->used_irqs, pbus->num_irqs);
     foreach_dynamic_sysbus_device(platform_bus_count_irqs, pbus);
-    pbus->done_gathering = true;
 }
 
 static void platform_bus_map_irq(PlatformBusDevice *pbus, SysBusDevice *sbdev,
@@ -163,12 +162,11 @@ static void platform_bus_map_mmio(PlatformBusDevice *pbus, SysBusDevice *sbdev,
 }
 
 /*
- * For each sysbus device, look for unassigned IRQ lines as well as
- * unassociated MMIO regions. Connect them to the platform bus if available.
+ * Look for unassigned IRQ lines as well as unassociated MMIO regions.
+ * Connect them to the platform bus if available.
  */
-static void link_sysbus_device(SysBusDevice *sbdev, void *opaque)
+void platform_bus_link_device(PlatformBusDevice *pbus, SysBusDevice *sbdev)
 {
-    PlatformBusDevice *pbus = opaque;
     int i;
 
     for (i = 0; sysbus_has_irq(sbdev, i); i++) {
@@ -180,19 +178,6 @@ static void link_sysbus_device(SysBusDevice *sbdev, void *opaque)
     }
 }
 
-static void platform_bus_init_notify(Notifier *notifier, void *data)
-{
-    PlatformBusDevice *pb = container_of(notifier, PlatformBusDevice, notifier);
-
-    /*
-     * Generate a bitmap of used IRQ lines, as the user might have specified
-     * them on the command line.
-     */
-    plaform_bus_refresh_irqs(pb);
-
-    foreach_dynamic_sysbus_device(link_sysbus_device, pb);
-}
-
 static void platform_bus_realize(DeviceState *dev, Error **errp)
 {
     PlatformBusDevice *pbus;
@@ -211,12 +196,8 @@ static void platform_bus_realize(DeviceState *dev, Error **errp)
         sysbus_init_irq(d, &pbus->irqs[i]);
     }
 
-    /*
-     * Register notifier that allows us to gather dangling devices once the
-     * machine is completely assembled
-     */
-    pbus->notifier.notify = platform_bus_init_notify;
-    qemu_add_machine_init_done_notifier(&pbus->notifier);
+    /* some devices might be initialized before so update used IRQs map */
+    plaform_bus_refresh_irqs(pbus);
 }
 
 static Property platform_bus_properties[] = {
diff --git a/hw/i386/pc.c b/hw/i386/pc.c
index 868893d..d768930 100644
--- a/hw/i386/pc.c
+++ b/hw/i386/pc.c
@@ -2051,15 +2051,12 @@ static void pc_machine_device_unplug_cb(HotplugHandler *hotplug_dev,
 static HotplugHandler *pc_get_hotpug_handler(MachineState *machine,
                                              DeviceState *dev)
 {
-    PCMachineClass *pcmc = PC_MACHINE_GET_CLASS(machine);
-
     if (object_dynamic_cast(OBJECT(dev), TYPE_PC_DIMM) ||
         object_dynamic_cast(OBJECT(dev), TYPE_CPU)) {
         return HOTPLUG_HANDLER(machine);
     }
 
-    return pcmc->get_hotplug_handler ?
-        pcmc->get_hotplug_handler(machine, dev) : NULL;
+    return NULL;
 }
 
 static void
@@ -2339,7 +2336,6 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
     HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(oc);
     NMIClass *nc = NMI_CLASS(oc);
 
-    pcmc->get_hotplug_handler = mc->get_hotplug_handler;
     pcmc->pci_enabled = true;
     pcmc->has_acpi_build = true;
     pcmc->rsdp_in_ram = true;
@@ -2354,6 +2350,7 @@ static void pc_machine_class_init(ObjectClass *oc, void *data)
     pcmc->acpi_data_size = 0x20000 + 0x8000;
     pcmc->save_tsc_khz = true;
     pcmc->linuxboot_dma_enabled = true;
+    assert(!mc->get_hotplug_handler);
     mc->get_hotplug_handler = pc_get_hotpug_handler;
     mc->cpu_index_to_instance_props = pc_cpu_index_to_props;
     mc->get_default_cpu_node_id = pc_get_default_cpu_node_id;
diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c
index 748a8d2..826053e 100644
--- a/hw/ppc/e500.c
+++ b/hw/ppc/e500.c
@@ -222,16 +222,15 @@ static void sysbus_device_create_devtree(SysBusDevice *sbdev, void *opaque)
     }
 }
 
-static void platform_bus_create_devtree(const PPCE500MachineClass *pmc,
+static void platform_bus_create_devtree(PPCE500MachineState *pms,
                                         void *fdt, const char *mpic)
 {
+    const PPCE500MachineClass *pmc = PPCE500_MACHINE_GET_CLASS(pms);
     gchar *node = g_strdup_printf("/platform@%"PRIx64, pmc->platform_bus_base);
     const char platcomp[] = "qemu,platform\0simple-bus";
     uint64_t addr = pmc->platform_bus_base;
     uint64_t size = pmc->platform_bus_size;
     int irq_start = pmc->platform_bus_first_irq;
-    PlatformBusDevice *pbus;
-    DeviceState *dev;
 
     /* Create a /platform node that we can put all devices into */
 
@@ -246,22 +245,17 @@ static void platform_bus_create_devtree(const PPCE500MachineClass *pmc,
 
     qemu_fdt_setprop_phandle(fdt, node, "interrupt-parent", mpic);
 
-    dev = qdev_find_recursive(sysbus_get_default(), TYPE_PLATFORM_BUS_DEVICE);
-    pbus = PLATFORM_BUS_DEVICE(dev);
-
-    /* We can only create dt nodes for dynamic devices when they're ready */
-    if (pbus->done_gathering) {
-        PlatformDevtreeData data = {
-            .fdt = fdt,
-            .mpic = mpic,
-            .irq_start = irq_start,
-            .node = node,
-            .pbus = pbus,
-        };
+    /* Create dt nodes for dynamic devices */
+    PlatformDevtreeData data = {
+        .fdt = fdt,
+        .mpic = mpic,
+        .irq_start = irq_start,
+        .node = node,
+        .pbus = pms->pbus_dev,
+    };
 
-        /* Loop through all dynamic sysbus devices and create nodes for them */
-        foreach_dynamic_sysbus_device(sysbus_device_create_devtree, &data);
-    }
+    /* Loop through all dynamic sysbus devices and create nodes for them */
+    foreach_dynamic_sysbus_device(sysbus_device_create_devtree, &data);
 
     g_free(node);
 }
@@ -533,8 +527,8 @@ static int ppce500_load_device_tree(PPCE500MachineState *pms,
     }
     g_free(soc);
 
-    if (pmc->has_platform_bus) {
-        platform_bus_create_devtree(pmc, fdt, mpic);
+    if (pms->pbus_dev) {
+        platform_bus_create_devtree(pms, fdt, mpic);
     }
     g_free(mpic);
 
@@ -953,8 +947,9 @@ void ppce500_init(MachineState *machine)
         qdev_prop_set_uint32(dev, "num_irqs", pmc->platform_bus_num_irqs);
         qdev_prop_set_uint32(dev, "mmio_size", pmc->platform_bus_size);
         qdev_init_nofail(dev);
-        s = SYS_BUS_DEVICE(dev);
+        pms->pbus_dev = PLATFORM_BUS_DEVICE(dev);
 
+        s = SYS_BUS_DEVICE(pms->pbus_dev);
         for (i = 0; i < pmc->platform_bus_num_irqs; i++) {
             int irqn = pmc->platform_bus_first_irq + i;
             sysbus_connect_irq(s, i, qdev_get_gpio_in(mpicdev, irqn));
@@ -1097,6 +1092,7 @@ static const TypeInfo ppce500_info = {
     .name          = TYPE_PPCE500_MACHINE,
     .parent        = TYPE_MACHINE,
     .abstract      = true,
+    .instance_size = sizeof(PPCE500MachineState),
     .class_size    = sizeof(PPCE500MachineClass),
 };
 
diff --git a/hw/ppc/e500.h b/hw/ppc/e500.h
index 621403b..3fd9f82 100644
--- a/hw/ppc/e500.h
+++ b/hw/ppc/e500.h
@@ -2,11 +2,16 @@
 #define PPCE500_H
 
 #include "hw/boards.h"
+#include "hw/platform-bus.h"
 
 typedef struct PPCE500MachineState {
     /*< private >*/
     MachineState parent_obj;
 
+    /* points to instance of TYPE_PLATFORM_BUS_DEVICE if
+     * board supports dynamic sysbus devices
+     */
+    PlatformBusDevice *pbus_dev;
 } PPCE500MachineState;
 
 typedef struct PPCE500MachineClass {
diff --git a/hw/ppc/e500plat.c b/hw/ppc/e500plat.c
index f69aadb..d8e3f20 100644
--- a/hw/ppc/e500plat.c
+++ b/hw/ppc/e500plat.c
@@ -43,13 +43,41 @@ static void e500plat_init(MachineState *machine)
     ppce500_init(machine);
 }
 
+static void e500plat_machine_device_plug_cb(HotplugHandler *hotplug_dev,
+                                            DeviceState *dev, Error **errp)
+{
+    PPCE500MachineState *pms = PPCE500_MACHINE(hotplug_dev);
+
+    if (pms->pbus_dev) {
+        if (object_dynamic_cast(OBJECT(dev), TYPE_SYS_BUS_DEVICE)) {
+            platform_bus_link_device(pms->pbus_dev, SYS_BUS_DEVICE(dev));
+        }
+    }
+}
+
+static
+HotplugHandler *e500plat_machine_get_hotpug_handler(MachineState *machine,
+                                                    DeviceState *dev)
+{
+    if (object_dynamic_cast(OBJECT(dev), TYPE_SYS_BUS_DEVICE)) {
+        return HOTPLUG_HANDLER(machine);
+    }
+
+    return NULL;
+}
+
 #define TYPE_E500PLAT_MACHINE  MACHINE_TYPE_NAME("ppce500")
 
 static void e500plat_machine_class_init(ObjectClass *oc, void *data)
 {
     PPCE500MachineClass *pmc = PPCE500_MACHINE_CLASS(oc);
+    HotplugHandlerClass *hc = HOTPLUG_HANDLER_CLASS(oc);
     MachineClass *mc = MACHINE_CLASS(oc);
 
+    assert(!mc->get_hotplug_handler);
+    mc->get_hotplug_handler = e500plat_machine_get_hotpug_handler;
+    hc->plug = e500plat_machine_device_plug_cb;
+
     pmc->pci_first_slot = 0x1;
     pmc->pci_nr_slots = PCI_SLOT_MAX - 1;
     pmc->fixup_devtree = e500plat_fixup_devtree;
@@ -77,6 +105,10 @@ static const TypeInfo e500plat_info = {
     .name          = TYPE_E500PLAT_MACHINE,
     .parent        = TYPE_PPCE500_MACHINE,
     .class_init    = e500plat_machine_class_init,
+    .interfaces    = (InterfaceInfo[]) {
+         { TYPE_HOTPLUG_HANDLER },
+         { }
+    }
 };
 
 static void e500plat_register_types(void)
diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index a1abcba..ebf30dd 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -3980,6 +3980,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
     mc->kvm_type = spapr_kvm_type;
     machine_class_allow_dynamic_sysbus_dev(mc, TYPE_SPAPR_PCI_HOST_BRIDGE);
     mc->pci_allow_0_address = true;
+    assert(!mc->get_hotplug_handler);
     mc->get_hotplug_handler = spapr_get_hotplug_handler;
     hc->pre_plug = spapr_machine_device_pre_plug;
     hc->plug = spapr_machine_device_plug;
diff --git a/hw/s390x/s390-virtio-ccw.c b/hw/s390x/s390-virtio-ccw.c
index 100dfdc..5796e24 100644
--- a/hw/s390x/s390-virtio-ccw.c
+++ b/hw/s390x/s390-virtio-ccw.c
@@ -491,6 +491,7 @@ static void ccw_machine_class_init(ObjectClass *oc, void *data)
     mc->no_sdcard = 1;
     mc->max_cpus = S390_MAX_CPUS;
     mc->has_hotpluggable_cpus = true;
+    assert(!mc->get_hotplug_handler);
     mc->get_hotplug_handler = s390_get_hotplug_handler;
     mc->cpu_index_to_instance_props = s390_cpu_index_to_props;
     mc->possible_cpu_arch_ids = s390_possible_cpu_arch_ids;