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 = xics_spapr_alloc(spapr->xics, 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 /* Represents sPAPR hcall VIO devices */ 542 543 static int spapr_vio_bridge_init(SysBusDevice *dev) 544 { 545 /* nothing */ 546 return 0; 547 } 548 549 static void spapr_vio_bridge_class_init(ObjectClass *klass, void *data) 550 { 551 SysBusDeviceClass *k = SYS_BUS_DEVICE_CLASS(klass); 552 DeviceClass *dc = DEVICE_CLASS(klass); 553 554 dc->fw_name = "vdevice"; 555 k->init = spapr_vio_bridge_init; 556 } 557 558 static const TypeInfo spapr_vio_bridge_info = { 559 .name = TYPE_SPAPR_VIO_BRIDGE, 560 .parent = TYPE_SYS_BUS_DEVICE, 561 .class_init = spapr_vio_bridge_class_init, 562 }; 563 564 const VMStateDescription vmstate_spapr_vio = { 565 .name = "spapr_vio", 566 .version_id = 1, 567 .minimum_version_id = 1, 568 .fields = (VMStateField[]) { 569 /* Sanity check */ 570 VMSTATE_UINT32_EQUAL(reg, VIOsPAPRDevice), 571 VMSTATE_UINT32_EQUAL(irq, VIOsPAPRDevice), 572 573 /* General VIO device state */ 574 VMSTATE_UINT64(signal_state, VIOsPAPRDevice), 575 VMSTATE_UINT64(crq.qladdr, VIOsPAPRDevice), 576 VMSTATE_UINT32(crq.qsize, VIOsPAPRDevice), 577 VMSTATE_UINT32(crq.qnext, VIOsPAPRDevice), 578 579 VMSTATE_END_OF_LIST() 580 }, 581 }; 582 583 static void vio_spapr_device_class_init(ObjectClass *klass, void *data) 584 { 585 DeviceClass *k = DEVICE_CLASS(klass); 586 k->realize = spapr_vio_busdev_realize; 587 k->reset = spapr_vio_busdev_reset; 588 k->bus_type = TYPE_SPAPR_VIO_BUS; 589 k->props = spapr_vio_props; 590 } 591 592 static const TypeInfo spapr_vio_type_info = { 593 .name = TYPE_VIO_SPAPR_DEVICE, 594 .parent = TYPE_DEVICE, 595 .instance_size = sizeof(VIOsPAPRDevice), 596 .abstract = true, 597 .class_size = sizeof(VIOsPAPRDeviceClass), 598 .class_init = vio_spapr_device_class_init, 599 }; 600 601 static void spapr_vio_register_types(void) 602 { 603 type_register_static(&spapr_vio_bus_info); 604 type_register_static(&spapr_vio_bridge_info); 605 type_register_static(&spapr_vio_type_info); 606 } 607 608 type_init(spapr_vio_register_types) 609 610 static int compare_reg(const void *p1, const void *p2) 611 { 612 VIOsPAPRDevice const *dev1, *dev2; 613 614 dev1 = (VIOsPAPRDevice *)*(DeviceState **)p1; 615 dev2 = (VIOsPAPRDevice *)*(DeviceState **)p2; 616 617 if (dev1->reg < dev2->reg) { 618 return -1; 619 } 620 if (dev1->reg == dev2->reg) { 621 return 0; 622 } 623 624 /* dev1->reg > dev2->reg */ 625 return 1; 626 } 627 628 void spapr_dt_vdevice(VIOsPAPRBus *bus, void *fdt) 629 { 630 DeviceState *qdev, **qdevs; 631 BusChild *kid; 632 int i, num, ret = 0; 633 int node; 634 635 _FDT(node = fdt_add_subnode(fdt, 0, "vdevice")); 636 637 _FDT(fdt_setprop_string(fdt, node, "device_type", "vdevice")); 638 _FDT(fdt_setprop_string(fdt, node, "compatible", "IBM,vdevice")); 639 _FDT(fdt_setprop_cell(fdt, node, "#address-cells", 1)); 640 _FDT(fdt_setprop_cell(fdt, node, "#size-cells", 0)); 641 _FDT(fdt_setprop_cell(fdt, node, "#interrupt-cells", 2)); 642 _FDT(fdt_setprop(fdt, node, "interrupt-controller", NULL, 0)); 643 644 /* Count qdevs on the bus list */ 645 num = 0; 646 QTAILQ_FOREACH(kid, &bus->bus.children, sibling) { 647 num++; 648 } 649 650 /* Copy out into an array of pointers */ 651 qdevs = g_malloc(sizeof(qdev) * num); 652 num = 0; 653 QTAILQ_FOREACH(kid, &bus->bus.children, sibling) { 654 qdevs[num++] = kid->child; 655 } 656 657 /* Sort the array */ 658 qsort(qdevs, num, sizeof(qdev), compare_reg); 659 660 /* Hack alert. Give the devices to libfdt in reverse order, we happen 661 * to know that will mean they are in forward order in the tree. */ 662 for (i = num - 1; i >= 0; i--) { 663 VIOsPAPRDevice *dev = (VIOsPAPRDevice *)(qdevs[i]); 664 VIOsPAPRDeviceClass *vdc = VIO_SPAPR_DEVICE_GET_CLASS(dev); 665 666 ret = vio_make_devnode(dev, fdt); 667 if (ret < 0) { 668 error_report("Couldn't create device node /vdevice/%s@%"PRIx32, 669 vdc->dt_name, dev->reg); 670 exit(1); 671 } 672 } 673 674 g_free(qdevs); 675 } 676 677 gchar *spapr_vio_stdout_path(VIOsPAPRBus *bus) 678 { 679 VIOsPAPRDevice *dev; 680 char *name, *path; 681 682 dev = spapr_vty_get_default(bus); 683 if (!dev) { 684 return NULL; 685 } 686 687 name = spapr_vio_get_dev_name(DEVICE(dev)); 688 path = g_strdup_printf("/vdevice/%s", name); 689 690 g_free(name); 691 return path; 692 } 693