hw/ppc/spapr_vio.c

   1 /*
   2  * QEMU sPAPR VIO code
   3  *
   4  * Copyright (c) 2010 David Gibson, IBM Corporation <dwg@au1.ibm.com>
   5  * Based on the s390 virtio bus code:
   6  * Copyright (c) 2009 Alexander Graf <agraf@suse.de>
   7  *
   8  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2 of the License, or (at your option) any later version.
  12  *
  13  * This library is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  20  */
  21
  22 #include "qemu/osdep.h"
  23 #include "qemu/error-report.h"
  24 #include "qapi/error.h"
  25 #include "hw/hw.h"
  26 #include "qemu/log.h"
  27 #include "sysemu/sysemu.h"
  28 #include "hw/boards.h"
  29 #include "hw/loader.h"
  30 #include "elf.h"
  31 #include "hw/sysbus.h"
  32 #include "sysemu/kvm.h"
  33 #include "sysemu/device_tree.h"
  34 #include "kvm_ppc.h"
  35
  36 #include "hw/ppc/spapr.h"
  37 #include "hw/ppc/spapr_vio.h"
  38 #include "hw/ppc/xics.h"
  39 #include "hw/ppc/fdt.h"
  40 #include "trace.h"
  41
  42 #include <libfdt.h>
  43
  44 static Property spapr_vio_props[] = {
  45     DEFINE_PROP_UINT32("irq", VIOsPAPRDevice, irq, 0), \
  46     DEFINE_PROP_END_OF_LIST(),
  47 };
  48
  49 static char *spapr_vio_get_dev_name(DeviceState *qdev)
  50 {
  51     VIOsPAPRDevice *dev = VIO_SPAPR_DEVICE(qdev);
  52     VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
  53
  54     /* Device tree style name device@reg */
  55     return g_strdup_printf("%s@%x", pc->dt_name, dev->reg);
  56 }
  57
  58 static void spapr_vio_bus_class_init(ObjectClass *klass, void *data)
  59 {
  60     BusClass *k = BUS_CLASS(klass);
  61
  62     k->get_dev_path = spapr_vio_get_dev_name;
  63     k->get_fw_dev_path = spapr_vio_get_dev_name;
  64 }
  65
  66 static const TypeInfo spapr_vio_bus_info = {
  67     .name = TYPE_SPAPR_VIO_BUS,
  68     .parent = TYPE_BUS,
  69     .class_init = spapr_vio_bus_class_init,
  70     .instance_size = sizeof(VIOsPAPRBus),
  71 };
  72
  73 VIOsPAPRDevice *spapr_vio_find_by_reg(VIOsPAPRBus *bus, uint32_t reg)
  74 {
  75     BusChild *kid;
  76     VIOsPAPRDevice *dev = NULL;
  77
  78     QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
  79         dev = (VIOsPAPRDevice *)kid->child;
  80         if (dev->reg == reg) {
  81             return dev;
  82         }
  83     }
  84
  85     return NULL;
  86 }
  87
  88 static int vio_make_devnode(VIOsPAPRDevice *dev,
  89                             void *fdt)
  90 {
  91     VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
  92     int vdevice_off, node_off, ret;
  93     char *dt_name;
  94
  95     vdevice_off = fdt_path_offset(fdt, "/vdevice");
  96     if (vdevice_off < 0) {
  97         return vdevice_off;
  98     }
  99
 100     dt_name = spapr_vio_get_dev_name(DEVICE(dev));
 101     node_off = fdt_add_subnode(fdt, vdevice_off, dt_name);
 102     g_free(dt_name);
 103     if (node_off < 0) {
 104         return node_off;
 105     }
 106
 107     ret = fdt_setprop_cell(fdt, node_off, "reg", dev->reg);
 108     if (ret < 0) {
 109         return ret;
 110     }
 111
 112     if (pc->dt_type) {
 113         ret = fdt_setprop_string(fdt, node_off, "device_type",
 114                                  pc->dt_type);
 115         if (ret < 0) {
 116             return ret;
 117         }
 118     }
 119
 120     if (pc->dt_compatible) {
 121         ret = fdt_setprop_string(fdt, node_off, "compatible",
 122                                  pc->dt_compatible);
 123         if (ret < 0) {
 124             return ret;
 125         }
 126     }
 127
 128     if (dev->irq) {
 129         uint32_t ints_prop[] = {cpu_to_be32(dev->irq), 0};
 130
 131         ret = fdt_setprop(fdt, node_off, "interrupts", ints_prop,
 132                           sizeof(ints_prop));
 133         if (ret < 0) {
 134             return ret;
 135         }
 136     }
 137
 138     ret = spapr_tcet_dma_dt(fdt, node_off, "ibm,my-dma-window", dev->tcet);
 139     if (ret < 0) {
 140         return ret;
 141     }
 142
 143     if (pc->devnode) {
 144         ret = (pc->devnode)(dev, fdt, node_off);
 145         if (ret < 0) {
 146             return ret;
 147         }
 148     }
 149
 150     return node_off;
 151 }
 152
 153 /*
 154  * CRQ handling
 155  */
 156 static target_ulong h_reg_crq(PowerPCCPU *cpu, sPAPRMachineState *spapr,
 157                               target_ulong opcode, target_ulong *args)
 158 {
 159     target_ulong reg = args[0];
 160     target_ulong queue_addr = args[1];
 161     target_ulong queue_len = args[2];
 162     VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
 163
 164     if (!dev) {
 165         hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
 166         return H_PARAMETER;
 167     }
 168
 169     /* We can't grok a queue size bigger than 256M for now */
 170     if (queue_len < 0x1000 || queue_len > 0x10000000) {
 171         hcall_dprintf("Queue size too small or too big (0x" TARGET_FMT_lx
 172                       ")\n", queue_len);
 173         return H_PARAMETER;
 174     }
 175
 176     /* Check queue alignment */
 177     if (queue_addr & 0xfff) {
 178         hcall_dprintf("Queue not aligned (0x" TARGET_FMT_lx ")\n", queue_addr);
 179         return H_PARAMETER;
 180     }
 181
 182     /* Check if device supports CRQs */
 183     if (!dev->crq.SendFunc) {
 184         hcall_dprintf("Device does not support CRQ\n");
 185         return H_NOT_FOUND;
 186     }
 187
 188     /* Already a queue ? */
 189     if (dev->crq.qsize) {
 190         hcall_dprintf("CRQ already registered\n");
 191         return H_RESOURCE;
 192     }
 193     dev->crq.qladdr = queue_addr;
 194     dev->crq.qsize = queue_len;
 195     dev->crq.qnext = 0;
 196
 197     trace_spapr_vio_h_reg_crq(reg, queue_addr, queue_len);
 198     return H_SUCCESS;
 199 }
 200
 201 static target_ulong free_crq(VIOsPAPRDevice *dev)
 202 {
 203     dev->crq.qladdr = 0;
 204     dev->crq.qsize = 0;
 205     dev->crq.qnext = 0;
 206
 207     trace_spapr_vio_free_crq(dev->reg);
 208
 209     return H_SUCCESS;
 210 }
 211
 212 static target_ulong h_free_crq(PowerPCCPU *cpu, sPAPRMachineState *spapr,
 213                                target_ulong opcode, target_ulong *args)
 214 {
 215     target_ulong reg = args[0];
 216     VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
 217
 218     if (!dev) {
 219         hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
 220         return H_PARAMETER;
 221     }
 222
 223     return free_crq(dev);
 224 }
 225
 226 static target_ulong h_send_crq(PowerPCCPU *cpu, sPAPRMachineState *spapr,
 227                                target_ulong opcode, target_ulong *args)
 228 {
 229     target_ulong reg = args[0];
 230     target_ulong msg_hi = args[1];
 231     target_ulong msg_lo = args[2];
 232     VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
 233     uint64_t crq_mangle[2];
 234
 235     if (!dev) {
 236         hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
 237         return H_PARAMETER;
 238     }
 239     crq_mangle[0] = cpu_to_be64(msg_hi);
 240     crq_mangle[1] = cpu_to_be64(msg_lo);
 241
 242     if (dev->crq.SendFunc) {
 243         return dev->crq.SendFunc(dev, (uint8_t *)crq_mangle);
 244     }
 245
 246     return H_HARDWARE;
 247 }
 248
 249 static target_ulong h_enable_crq(PowerPCCPU *cpu, sPAPRMachineState *spapr,
 250                                  target_ulong opcode, target_ulong *args)
 251 {
 252     target_ulong reg = args[0];
 253     VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
 254
 255     if (!dev) {
 256         hcall_dprintf("Unit 0x" TARGET_FMT_lx " does not exist\n", reg);
 257         return H_PARAMETER;
 258     }
 259
 260     return 0;
 261 }
 262
 263 /* Returns negative error, 0 success, or positive: queue full */
 264 int spapr_vio_send_crq(VIOsPAPRDevice *dev, uint8_t *crq)
 265 {
 266     int rc;
 267     uint8_t byte;
 268
 269     if (!dev->crq.qsize) {
 270         error_report("spapr_vio_send_creq on uninitialized queue");
 271         return -1;
 272     }
 273
 274     /* Maybe do a fast path for KVM just writing to the pages */
 275     rc = spapr_vio_dma_read(dev, dev->crq.qladdr + dev->crq.qnext, &byte, 1);
 276     if (rc) {
 277         return rc;
 278     }
 279     if (byte != 0) {
 280         return 1;
 281     }
 282
 283     rc = spapr_vio_dma_write(dev, dev->crq.qladdr + dev->crq.qnext + 8,
 284                              &crq[8], 8);
 285     if (rc) {
 286         return rc;
 287     }
 288
 289     kvmppc_eieio();
 290
 291     rc = spapr_vio_dma_write(dev, dev->crq.qladdr + dev->crq.qnext, crq, 8);
 292     if (rc) {
 293         return rc;
 294     }
 295
 296     dev->crq.qnext = (dev->crq.qnext + 16) % dev->crq.qsize;
 297
 298     if (dev->signal_state & 1) {
 299         qemu_irq_pulse(spapr_vio_qirq(dev));
 300     }
 301
 302     return 0;
 303 }
 304
 305 /* "quiesce" handling */
 306
 307 static void spapr_vio_quiesce_one(VIOsPAPRDevice *dev)
 308 {
 309     if (dev->tcet) {
 310         device_reset(DEVICE(dev->tcet));
 311     }
 312     free_crq(dev);
 313 }
 314
 315 void spapr_vio_set_bypass(VIOsPAPRDevice *dev, bool bypass)
 316 {
 317     if (!dev->tcet) {
 318         return;
 319     }
 320
 321     memory_region_set_enabled(&dev->mrbypass, bypass);
 322     memory_region_set_enabled(spapr_tce_get_iommu(dev->tcet), !bypass);
 323
 324     dev->tcet->bypass = bypass;
 325 }
 326
 327 static void rtas_set_tce_bypass(PowerPCCPU *cpu, sPAPRMachineState *spapr,
 328                                 uint32_t token,
 329                                 uint32_t nargs, target_ulong args,
 330                                 uint32_t nret, target_ulong rets)
 331 {
 332     VIOsPAPRBus *bus = spapr->vio_bus;
 333     VIOsPAPRDevice *dev;
 334     uint32_t unit, enable;
 335
 336     if (nargs != 2) {
 337         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
 338         return;
 339     }
 340     unit = rtas_ld(args, 0);
 341     enable = rtas_ld(args, 1);
 342     dev = spapr_vio_find_by_reg(bus, unit);
 343     if (!dev) {
 344         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
 345         return;
 346     }
 347
 348     if (!dev->tcet) {
 349         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
 350         return;
 351     }
 352
 353     spapr_vio_set_bypass(dev, !!enable);
 354
 355     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
 356 }
 357
 358 static void rtas_quiesce(PowerPCCPU *cpu, sPAPRMachineState *spapr,
 359                          uint32_t token,
 360                          uint32_t nargs, target_ulong args,
 361                          uint32_t nret, target_ulong rets)
 362 {
 363     VIOsPAPRBus *bus = spapr->vio_bus;
 364     BusChild *kid;
 365     VIOsPAPRDevice *dev = NULL;
 366
 367     if (nargs != 0) {
 368         rtas_st(rets, 0, RTAS_OUT_PARAM_ERROR);
 369         return;
 370     }
 371
 372     QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
 373         dev = (VIOsPAPRDevice *)kid->child;
 374         spapr_vio_quiesce_one(dev);
 375     }
 376
 377     rtas_st(rets, 0, RTAS_OUT_SUCCESS);
 378 }
 379
 380 static VIOsPAPRDevice *reg_conflict(VIOsPAPRDevice *dev)
 381 {
 382     VIOsPAPRBus *bus = SPAPR_VIO_BUS(dev->qdev.parent_bus);
 383     BusChild *kid;
 384     VIOsPAPRDevice *other;
 385
 386     /*
 387      * Check for a device other than the given one which is already
 388      * using the requested address. We have to open code this because
 389      * the given dev might already be in the list.
 390      */
 391     QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
 392         other = VIO_SPAPR_DEVICE(kid->child);
 393
 394         if (other != dev && other->reg == dev->reg) {
 395             return other;
 396         }
 397     }
 398
 399     return 0;
 400 }
 401
 402 static void spapr_vio_busdev_reset(DeviceState *qdev)
 403 {
 404     VIOsPAPRDevice *dev = VIO_SPAPR_DEVICE(qdev);
 405     VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
 406
 407     /* Shut down the request queue and TCEs if necessary */
 408     spapr_vio_quiesce_one(dev);
 409
 410     dev->signal_state = 0;
 411
 412     spapr_vio_set_bypass(dev, false);
 413     if (pc->reset) {
 414         pc->reset(dev);
 415     }
 416 }
 417
 418 static void spapr_vio_busdev_realize(DeviceState *qdev, Error **errp)
 419 {
 420     sPAPRMachineState *spapr = SPAPR_MACHINE(qdev_get_machine());
 421     VIOsPAPRDevice *dev = (VIOsPAPRDevice *)qdev;
 422     VIOsPAPRDeviceClass *pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
 423     char *id;
 424     Error *local_err = NULL;
 425
 426     if (dev->reg != -1) {
 427         /*
 428          * Explicitly assigned address, just verify that no-one else
 429          * is using it.  other mechanism). We have to open code this
 430          * rather than using spapr_vio_find_by_reg() because sdev
 431          * itself is already in the list.
 432          */
 433         VIOsPAPRDevice *other = reg_conflict(dev);
 434
 435         if (other) {
 436             error_setg(errp, "%s and %s devices conflict at address %#x",
 437                        object_get_typename(OBJECT(qdev)),
 438                        object_get_typename(OBJECT(&other->qdev)),
 439                        dev->reg);
 440             return;
 441         }
 442     } else {
 443         /* Need to assign an address */
 444         VIOsPAPRBus *bus = SPAPR_VIO_BUS(dev->qdev.parent_bus);
 445
 446         do {
 447             dev->reg = bus->next_reg++;
 448         } while (reg_conflict(dev));
 449     }
 450
 451     /* Don't overwrite ids assigned on the command line */
 452     if (!dev->qdev.id) {
 453         id = spapr_vio_get_dev_name(DEVICE(dev));
 454         dev->qdev.id = id;
 455     }
 456
 457     dev->irq = spapr_ics_alloc(spapr->ics, dev->irq, false, &local_err);
 458     if (local_err) {
 459         error_propagate(errp, local_err);
 460         return;
 461     }
 462
 463     if (pc->rtce_window_size) {
 464         uint32_t liobn = SPAPR_VIO_LIOBN(dev->reg);
 465
 466         memory_region_init(&dev->mrroot, OBJECT(dev), "iommu-spapr-root",
 467                            ram_size);
 468         memory_region_init_alias(&dev->mrbypass, OBJECT(dev),
 469                                  "iommu-spapr-bypass", get_system_memory(),
 470                                  0, ram_size);
 471         memory_region_add_subregion_overlap(&dev->mrroot, 0, &dev->mrbypass, 1);
 472         address_space_init(&dev->as, &dev->mrroot, qdev->id);
 473
 474         dev->tcet = spapr_tce_new_table(qdev, liobn);
 475         spapr_tce_table_enable(dev->tcet, SPAPR_TCE_PAGE_SHIFT, 0,
 476                                pc->rtce_window_size >> SPAPR_TCE_PAGE_SHIFT);
 477         dev->tcet->vdev = dev;
 478         memory_region_add_subregion_overlap(&dev->mrroot, 0,
 479                                             spapr_tce_get_iommu(dev->tcet), 2);
 480     }
 481
 482     pc->realize(dev, errp);
 483 }
 484
 485 static target_ulong h_vio_signal(PowerPCCPU *cpu, sPAPRMachineState *spapr,
 486                                  target_ulong opcode,
 487                                  target_ulong *args)
 488 {
 489     target_ulong reg = args[0];
 490     target_ulong mode = args[1];
 491     VIOsPAPRDevice *dev = spapr_vio_find_by_reg(spapr->vio_bus, reg);
 492     VIOsPAPRDeviceClass *pc;
 493
 494     if (!dev) {
 495         return H_PARAMETER;
 496     }
 497
 498     pc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
 499
 500     if (mode & ~pc->signal_mask) {
 501         return H_PARAMETER;
 502     }
 503
 504     dev->signal_state = mode;
 505
 506     return H_SUCCESS;
 507 }
 508
 509 VIOsPAPRBus *spapr_vio_bus_init(void)
 510 {
 511     VIOsPAPRBus *bus;
 512     BusState *qbus;
 513     DeviceState *dev;
 514
 515     /* Create bridge device */
 516     dev = qdev_create(NULL, TYPE_SPAPR_VIO_BRIDGE);
 517     qdev_init_nofail(dev);
 518
 519     /* Create bus on bridge device */
 520     qbus = qbus_create(TYPE_SPAPR_VIO_BUS, dev, "spapr-vio");
 521     bus = SPAPR_VIO_BUS(qbus);
 522     bus->next_reg = 0x71000000;
 523
 524     /* hcall-vio */
 525     spapr_register_hypercall(H_VIO_SIGNAL, h_vio_signal);
 526
 527     /* hcall-crq */
 528     spapr_register_hypercall(H_REG_CRQ, h_reg_crq);
 529     spapr_register_hypercall(H_FREE_CRQ, h_free_crq);
 530     spapr_register_hypercall(H_SEND_CRQ, h_send_crq);
 531     spapr_register_hypercall(H_ENABLE_CRQ, h_enable_crq);
 532
 533     /* RTAS calls */
 534     spapr_rtas_register(RTAS_IBM_SET_TCE_BYPASS, "ibm,set-tce-bypass",
 535                         rtas_set_tce_bypass);
 536     spapr_rtas_register(RTAS_QUIESCE, "quiesce", rtas_quiesce);
 537
 538     return bus;
 539 }
 540
 541 static void spapr_vio_bridge_class_init(ObjectClass *klass, void *data)
 542 {
 543     DeviceClass *dc = DEVICE_CLASS(klass);
 544
 545     dc->fw_name = "vdevice";
 546 }
 547
 548 static const TypeInfo spapr_vio_bridge_info = {
 549     .name          = TYPE_SPAPR_VIO_BRIDGE,
 550     .parent        = TYPE_SYS_BUS_DEVICE,
 551     .class_init    = spapr_vio_bridge_class_init,
 552 };
 553
 554 const VMStateDescription vmstate_spapr_vio = {
 555     .name = "spapr_vio",
 556     .version_id = 1,
 557     .minimum_version_id = 1,
 558     .fields = (VMStateField[]) {
 559         /* Sanity check */
 560         VMSTATE_UINT32_EQUAL(reg, VIOsPAPRDevice, NULL),
 561         VMSTATE_UINT32_EQUAL(irq, VIOsPAPRDevice, NULL),
 562
 563         /* General VIO device state */
 564         VMSTATE_UINT64(signal_state, VIOsPAPRDevice),
 565         VMSTATE_UINT64(crq.qladdr, VIOsPAPRDevice),
 566         VMSTATE_UINT32(crq.qsize, VIOsPAPRDevice),
 567         VMSTATE_UINT32(crq.qnext, VIOsPAPRDevice),
 568
 569         VMSTATE_END_OF_LIST()
 570     },
 571 };
 572
 573 static void vio_spapr_device_class_init(ObjectClass *klass, void *data)
 574 {
 575     DeviceClass *k = DEVICE_CLASS(klass);
 576     k->realize = spapr_vio_busdev_realize;
 577     k->reset = spapr_vio_busdev_reset;
 578     k->bus_type = TYPE_SPAPR_VIO_BUS;
 579     k->props = spapr_vio_props;
 580 }
 581
 582 static const TypeInfo spapr_vio_type_info = {
 583     .name = TYPE_VIO_SPAPR_DEVICE,
 584     .parent = TYPE_DEVICE,
 585     .instance_size = sizeof(VIOsPAPRDevice),
 586     .abstract = true,
 587     .class_size = sizeof(VIOsPAPRDeviceClass),
 588     .class_init = vio_spapr_device_class_init,
 589 };
 590
 591 static void spapr_vio_register_types(void)
 592 {
 593     type_register_static(&spapr_vio_bus_info);
 594     type_register_static(&spapr_vio_bridge_info);
 595     type_register_static(&spapr_vio_type_info);
 596 }
 597
 598 type_init(spapr_vio_register_types)
 599
 600 static int compare_reg(const void *p1, const void *p2)
 601 {
 602     VIOsPAPRDevice const *dev1, *dev2;
 603
 604     dev1 = (VIOsPAPRDevice *)*(DeviceState **)p1;
 605     dev2 = (VIOsPAPRDevice *)*(DeviceState **)p2;
 606
 607     if (dev1->reg < dev2->reg) {
 608         return -1;
 609     }
 610     if (dev1->reg == dev2->reg) {
 611         return 0;
 612     }
 613
 614     /* dev1->reg > dev2->reg */
 615     return 1;
 616 }
 617
 618 void spapr_dt_vdevice(VIOsPAPRBus *bus, void *fdt)
 619 {
 620     DeviceState *qdev, **qdevs;
 621     BusChild *kid;
 622     int i, num, ret = 0;
 623     int node;
 624
 625     _FDT(node = fdt_add_subnode(fdt, 0, "vdevice"));
 626
 627     _FDT(fdt_setprop_string(fdt, node, "device_type", "vdevice"));
 628     _FDT(fdt_setprop_string(fdt, node, "compatible", "IBM,vdevice"));
 629     _FDT(fdt_setprop_cell(fdt, node, "#address-cells", 1));
 630     _FDT(fdt_setprop_cell(fdt, node, "#size-cells", 0));
 631     _FDT(fdt_setprop_cell(fdt, node, "#interrupt-cells", 2));
 632     _FDT(fdt_setprop(fdt, node, "interrupt-controller", NULL, 0));
 633
 634     /* Count qdevs on the bus list */
 635     num = 0;
 636     QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
 637         num++;
 638     }
 639
 640     /* Copy out into an array of pointers */
 641     qdevs = g_malloc(sizeof(qdev) * num);
 642     num = 0;
 643     QTAILQ_FOREACH(kid, &bus->bus.children, sibling) {
 644         qdevs[num++] = kid->child;
 645     }
 646
 647     /* Sort the array */
 648     qsort(qdevs, num, sizeof(qdev), compare_reg);
 649
 650     /* Hack alert. Give the devices to libfdt in reverse order, we happen
 651      * to know that will mean they are in forward order in the tree. */
 652     for (i = num - 1; i >= 0; i--) {
 653         VIOsPAPRDevice *dev = (VIOsPAPRDevice *)(qdevs[i]);
 654         VIOsPAPRDeviceClass *vdc = VIO_SPAPR_DEVICE_GET_CLASS(dev);
 655
 656         ret = vio_make_devnode(dev, fdt);
 657         if (ret < 0) {
 658             error_report("Couldn't create device node /vdevice/%s@%"PRIx32,
 659                          vdc->dt_name, dev->reg);
 660             exit(1);
 661         }
 662     }
 663
 664     g_free(qdevs);
 665 }
 666
 667 gchar *spapr_vio_stdout_path(VIOsPAPRBus *bus)
 668 {
 669     VIOsPAPRDevice *dev;
 670     char *name, *path;
 671
 672     dev = spapr_vty_get_default(bus);
 673     if (!dev) {
 674         return NULL;
 675     }
 676
 677     name = spapr_vio_get_dev_name(DEVICE(dev));
 678     path = g_strdup_printf("/vdevice/%s", name);
 679
 680     g_free(name);
 681     return path;
 682 }