[RFC,v2,3/7] PPC: e500: Support dynamically spawned sysbus devices

diff --git a/hw/ppc/e500.c b/hw/ppc/e500.c
index 1a5b30d..0ee8cbf 100644
--- a/hw/ppc/e500.c
+++ b/hw/ppc/e500.c
@@ -36,6 +36,8 @@ 
 #include "exec/address-spaces.h"
 #include "qemu/host-utils.h"
 #include "hw/pci-host/ppce500.h"
+#include "qemu/error-report.h"
+#include "hw/misc/dyn_sysbus_binding.h"
 
 #define EPAPR_MAGIC                (0x45504150)
 #define BINARY_DEVICE_TREE_FILE    "mpc8544ds.dtb"
@@ -47,6 +49,8 @@ 
 
 #define RAM_SIZES_ALIGN            (64UL << 20)
 
+#define E500_PLATFORM_BUS_PAGE_SHIFT 12
+
 /* TODO: parameterize */
 #define MPC8544_CCSRBAR_BASE       0xE0000000ULL
 #define MPC8544_CCSRBAR_SIZE       0x00100000ULL
@@ -122,6 +126,77 @@  static void dt_serial_create(void *fdt, unsigned long long offset,
     }
 }
 
+typedef struct PlatformDevtreeData {
+    void *fdt;
+    const char *mpic;
+    int irq_start;
+    const char *node;
+} PlatformDevtreeData;
+
+static int sysbus_device_create_devtree(Object *obj, void *opaque)
+{
+    PlatformDevtreeData *data = opaque;
+    Object *dev;
+    SysBusDevice *sbdev;
+    bool matched = false;
+
+    dev = object_dynamic_cast(obj, TYPE_SYS_BUS_DEVICE);
+    sbdev = (SysBusDevice *)dev;
+
+    if (!sbdev) {
+        /* Container, traverse it for children */
+        return object_child_foreach(obj, sysbus_device_create_devtree, data);
+    }
+
+    if (!matched) {
+        error_report("Device %s is not supported by this machine yet.",
+                     qdev_fw_name(DEVICE(dev)));
+        exit(1);
+    }
+
+    return 0;
+}
+
+static void platform_bus_create_devtree(PPCE500Params *params, void *fdt,
+                                        const char *mpic)
+{
+    gchar *node = g_strdup_printf("/platform@%"PRIx64,
+                                  params->dyn_sysbus_params.platform_bus_base);
+    const char platcomp[] = "qemu,platform\0simple-bus";
+    PlatformDevtreeData data;
+    Object *container;
+    uint64_t addr = params->dyn_sysbus_params.platform_bus_base;
+    uint64_t size = params->dyn_sysbus_params.platform_bus_size;
+    int irq_start = params->dyn_sysbus_params.platform_bus_first_irq;
+
+    /* Create a /platform node that we can put all devices into */
+
+    qemu_fdt_add_subnode(fdt, node);
+    qemu_fdt_setprop(fdt, node, "compatible", platcomp, sizeof(platcomp));
+
+    /* Our platform bus region is less than 32bit big, so 1 cell is enough for
+       address and size */
+    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_phandle(fdt, node, "interrupt-parent", mpic);
+
+    /* Loop through all devices and create nodes for known ones */
+
+    data.fdt = fdt;
+    data.mpic = mpic;
+    data.irq_start = irq_start;
+    data.node = node;
+
+    container = container_get(qdev_get_machine(), "/peripheral");
+    sysbus_device_create_devtree(container, &data);
+    container = container_get(qdev_get_machine(), "/peripheral-anon");
+    sysbus_device_create_devtree(container, &data);
+
+    g_free(node);
+}
+
 static int ppce500_load_device_tree(MachineState *machine,
                                     PPCE500Params *params,
                                     hwaddr addr,
@@ -379,6 +454,10 @@  static int ppce500_load_device_tree(MachineState *machine,
     qemu_fdt_setprop_cell(fdt, pci, "#address-cells", 3);
     qemu_fdt_setprop_string(fdt, "/aliases", "pci0", pci);
 
+    if (params->dyn_sysbus_params.has_platform_bus) {
+        platform_bus_create_devtree(params, fdt, mpic);
+    }
+
     params->fixup_devtree(params, fdt);
 
     if (toplevel_compat) {
@@ -769,6 +848,19 @@  void ppce500_init(MachineState *machine, PPCE500Params *params)
         cur_base = (32 * 1024 * 1024);
     }
 
+    /* Platform Devices */
+    if (params->dyn_sysbus_params.has_platform_bus) {
+        DynSysbusNotifier *notifier = g_new(DynSysbusNotifier, 1);
+        params->dyn_sysbus_params.page_shift =
+            E500_PLATFORM_BUS_PAGE_SHIFT;
+
+        notifier->notifier.notify = platform_bus_init_notify;
+        notifier->address_space_mem = address_space_mem;
+        notifier->mpic = mpic;
+        notifier->params = params->dyn_sysbus_params;
+        qemu_add_machine_init_done_notifier(&notifier->notifier);
+    }
+
     /* Load kernel. */
     if (machine->kernel_filename) {
         kernel_base = cur_base;
diff --git a/hw/ppc/e500.h b/hw/ppc/e500.h
index 08b25fa..c191f9d 100644
--- a/hw/ppc/e500.h
+++ b/hw/ppc/e500.h
@@ -2,6 +2,7 @@ 
 #define PPCE500_H
 
 #include "hw/boards.h"
+#include "hw/misc/dyn_sysbus_binding.h"
 
 typedef struct PPCE500Params {
     int pci_first_slot;
@@ -11,6 +12,7 @@  typedef struct PPCE500Params {
     void (*fixup_devtree)(struct PPCE500Params *params, void *fdt);
 
     int mpic_version;
+    DynSysbusParams dyn_sysbus_params;
 } PPCE500Params;
 
 void ppce500_init(MachineState *machine, PPCE500Params *params);
diff --git a/hw/ppc/e500plat.c b/hw/ppc/e500plat.c
index 27df31d..4150a2c 100644
--- a/hw/ppc/e500plat.c
+++ b/hw/ppc/e500plat.c
@@ -35,6 +35,14 @@  static void e500plat_init(MachineState *machine)
         .pci_nr_slots = PCI_SLOT_MAX - 1,
         .fixup_devtree = e500plat_fixup_devtree,
         .mpic_version = OPENPIC_MODEL_FSL_MPIC_42,
+        .dyn_sysbus_params = {
+            .has_platform_bus = true,
+            .platform_bus_base = 0xf00000000ULL,
+            .platform_bus_size = (128ULL * 1024 * 1024),
+            .platform_bus_first_irq = 5,
+            .platform_bus_num_irqs = 10,
+            .page_shift = 12 /* default */
+        }
     };
 
     /* Older KVM versions don't support EPR which breaks guests when we announce
@@ -51,6 +59,7 @@  static QEMUMachine e500plat_machine = {
     .desc = "generic paravirt e500 platform",
     .init = e500plat_init,
     .max_cpus = 32,
+    .has_dynamic_sysbus = true,
 };
 
 static void e500plat_machine_init(void)