hw/acpi/pcihp.c

   1 /*
   2  * QEMU<->ACPI BIOS PCI hotplug interface
   3  *
   4  * QEMU supports PCI hotplug via ACPI. This module
   5  * implements the interface between QEMU and the ACPI BIOS.
   6  * Interface specification - see docs/specs/acpi_pci_hotplug.txt
   7  *
   8  * Copyright (c) 2013, Red Hat Inc, Michael S. Tsirkin (mst@redhat.com)
   9  * Copyright (c) 2006 Fabrice Bellard
  10  *
  11  * This library is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU Lesser General Public
  13  * License version 2.1 as published by the Free Software Foundation.
  14  *
  15  * This library is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * Lesser General Public License for more details.
  19  *
  20  * You should have received a copy of the GNU Lesser General Public
  21  * License along with this library; if not, see <http://www.gnu.org/licenses/>
  22  *
  23  * Contributions after 2012-01-13 are licensed under the terms of the
  24  * GNU GPL, version 2 or (at your option) any later version.
  25  */
  26
  27 #include "qemu/osdep.h"
  28 #include "hw/acpi/pcihp.h"
  29
  30 #include "hw/pci-host/i440fx.h"
  31 #include "hw/pci/pci.h"
  32 #include "hw/pci/pci_bridge.h"
  33 #include "hw/pci/pci_host.h"
  34 #include "hw/pci/pcie_port.h"
  35 #include "hw/i386/acpi-build.h"
  36 #include "hw/acpi/acpi.h"
  37 #include "hw/pci/pci_bus.h"
  38 #include "migration/vmstate.h"
  39 #include "qapi/error.h"
  40 #include "qom/qom-qobject.h"
  41 #include "trace.h"
  42
  43 #define ACPI_PCIHP_SIZE 0x0018
  44 #define PCI_UP_BASE 0x0000
  45 #define PCI_DOWN_BASE 0x0004
  46 #define PCI_EJ_BASE 0x0008
  47 #define PCI_RMV_BASE 0x000c
  48 #define PCI_SEL_BASE 0x0010
  49 #define PCI_AIDX_BASE 0x0014
  50
  51 typedef struct AcpiPciHpFind {
  52     int bsel;
  53     PCIBus *bus;
  54 } AcpiPciHpFind;
  55
  56 static gint g_cmp_uint32(gconstpointer a, gconstpointer b, gpointer user_data)
  57 {
  58     return a - b;
  59 }
  60
  61 static GSequence *pci_acpi_index_list(void)
  62 {
  63     static GSequence *used_acpi_index_list;
  64
  65     if (!used_acpi_index_list) {
  66         used_acpi_index_list = g_sequence_new(NULL);
  67     }
  68     return used_acpi_index_list;
  69 }
  70
  71 static int acpi_pcihp_get_bsel(PCIBus *bus)
  72 {
  73     Error *local_err = NULL;
  74     uint64_t bsel = object_property_get_uint(OBJECT(bus), ACPI_PCIHP_PROP_BSEL,
  75                                              &local_err);
  76
  77     if (local_err || bsel >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
  78         if (local_err) {
  79             error_free(local_err);
  80         }
  81         return -1;
  82     } else {
  83         return bsel;
  84     }
  85 }
  86
  87 /* Assign BSEL property to all buses.  In the future, this can be changed
  88  * to only assign to buses that support hotplug.
  89  */
  90 static void *acpi_set_bsel(PCIBus *bus, void *opaque)
  91 {
  92     unsigned *bsel_alloc = opaque;
  93     unsigned *bus_bsel;
  94
  95     if (qbus_is_hotpluggable(BUS(bus))) {
  96         bus_bsel = g_malloc(sizeof *bus_bsel);
  97
  98         *bus_bsel = (*bsel_alloc)++;
  99         object_property_add_uint32_ptr(OBJECT(bus), ACPI_PCIHP_PROP_BSEL,
 100                                        bus_bsel, OBJ_PROP_FLAG_READ);
 101     }
 102
 103     return bsel_alloc;
 104 }
 105
 106 static void acpi_set_pci_info(void)
 107 {
 108     static bool bsel_is_set;
 109     Object *host = acpi_get_i386_pci_host();
 110     PCIBus *bus;
 111     unsigned bsel_alloc = ACPI_PCIHP_BSEL_DEFAULT;
 112
 113     if (bsel_is_set) {
 114         return;
 115     }
 116     bsel_is_set = true;
 117
 118     if (!host) {
 119         return;
 120     }
 121
 122     bus = PCI_HOST_BRIDGE(host)->bus;
 123     if (bus) {
 124         /* Scan all PCI buses. Set property to enable acpi based hotplug. */
 125         pci_for_each_bus_depth_first(bus, acpi_set_bsel, NULL, &bsel_alloc);
 126     }
 127 }
 128
 129 static void acpi_pcihp_disable_root_bus(void)
 130 {
 131     Object *host = acpi_get_i386_pci_host();
 132     PCIBus *bus;
 133
 134     bus = PCI_HOST_BRIDGE(host)->bus;
 135     if (bus && qbus_is_hotpluggable(BUS(bus))) {
 136         /* setting the hotplug handler to NULL makes the bus non-hotpluggable */
 137         qbus_set_hotplug_handler(BUS(bus), NULL);
 138     }
 139
 140     return;
 141 }
 142
 143 static void acpi_pcihp_test_hotplug_bus(PCIBus *bus, void *opaque)
 144 {
 145     AcpiPciHpFind *find = opaque;
 146     if (find->bsel == acpi_pcihp_get_bsel(bus)) {
 147         find->bus = bus;
 148     }
 149 }
 150
 151 static PCIBus *acpi_pcihp_find_hotplug_bus(AcpiPciHpState *s, int bsel)
 152 {
 153     AcpiPciHpFind find = { .bsel = bsel, .bus = NULL };
 154
 155     if (bsel < 0) {
 156         return NULL;
 157     }
 158
 159     pci_for_each_bus(s->root, acpi_pcihp_test_hotplug_bus, &find);
 160
 161     /* Make bsel 0 eject root bus if bsel property is not set,
 162      * for compatibility with non acpi setups.
 163      * TODO: really needed?
 164      */
 165     if (!bsel && !find.bus) {
 166         find.bus = s->root;
 167     }
 168
 169     /*
 170      * Check if find.bus is actually hotpluggable. If bsel is set to
 171      * NULL for example on the root bus in order to make it
 172      * non-hotpluggable, find.bus will match the root bus when bsel
 173      * is 0. See acpi_pcihp_test_hotplug_bus() above. Since the
 174      * bus is not hotpluggable however, we should not select the bus.
 175      * Instead, we should set find.bus to NULL in that case. In the check
 176      * below, we generalize this case for all buses, not just the root bus.
 177      * The callers of this function check for a null return value and
 178      * handle them appropriately.
 179      */
 180     if (find.bus && !qbus_is_hotpluggable(BUS(find.bus))) {
 181         find.bus = NULL;
 182     }
 183     return find.bus;
 184 }
 185
 186 static bool acpi_pcihp_pc_no_hotplug(AcpiPciHpState *s, PCIDevice *dev)
 187 {
 188     PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(dev);
 189     DeviceClass *dc = DEVICE_GET_CLASS(dev);
 190     /*
 191      * ACPI doesn't allow hotplug of bridge devices.  Don't allow
 192      * hot-unplug of bridge devices unless they were added by hotplug
 193      * (and so, not described by acpi).
 194      */
 195     return (pc->is_bridge && !dev->qdev.hotplugged) || !dc->hotpluggable;
 196 }
 197
 198 static void acpi_pcihp_eject_slot(AcpiPciHpState *s, unsigned bsel, unsigned slots)
 199 {
 200     HotplugHandler *hotplug_ctrl;
 201     BusChild *kid, *next;
 202     int slot = ctz32(slots);
 203     PCIBus *bus = acpi_pcihp_find_hotplug_bus(s, bsel);
 204
 205     trace_acpi_pci_eject_slot(bsel, slot);
 206
 207     if (!bus || slot > 31) {
 208         return;
 209     }
 210
 211     /* Mark request as complete */
 212     s->acpi_pcihp_pci_status[bsel].down &= ~(1U << slot);
 213     s->acpi_pcihp_pci_status[bsel].up &= ~(1U << slot);
 214
 215     QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
 216         DeviceState *qdev = kid->child;
 217         PCIDevice *dev = PCI_DEVICE(qdev);
 218         if (PCI_SLOT(dev->devfn) == slot) {
 219             if (!acpi_pcihp_pc_no_hotplug(s, dev)) {
 220                 /*
 221                  * partially_hotplugged is used by virtio-net failover:
 222                  * failover has asked the guest OS to unplug the device
 223                  * but we need to keep some references to the device
 224                  * to be able to plug it back in case of failure so
 225                  * we don't execute hotplug_handler_unplug().
 226                  */
 227                 if (dev->partially_hotplugged) {
 228                     /*
 229                      * pending_deleted_event is set to true when
 230                      * virtio-net failover asks to unplug the device,
 231                      * and set to false here when the operation is done
 232                      * This is used by the migration loop to detect the
 233                      * end of the operation and really start the migration.
 234                      */
 235                     qdev->pending_deleted_event = false;
 236                 } else {
 237                     hotplug_ctrl = qdev_get_hotplug_handler(qdev);
 238                     hotplug_handler_unplug(hotplug_ctrl, qdev, &error_abort);
 239                     object_unparent(OBJECT(qdev));
 240                 }
 241             }
 242         }
 243     }
 244 }
 245
 246 static void acpi_pcihp_update_hotplug_bus(AcpiPciHpState *s, int bsel)
 247 {
 248     BusChild *kid, *next;
 249     PCIBus *bus = acpi_pcihp_find_hotplug_bus(s, bsel);
 250
 251     /* Execute any pending removes during reset */
 252     while (s->acpi_pcihp_pci_status[bsel].down) {
 253         acpi_pcihp_eject_slot(s, bsel, s->acpi_pcihp_pci_status[bsel].down);
 254     }
 255
 256     s->acpi_pcihp_pci_status[bsel].hotplug_enable = ~0;
 257
 258     if (!bus) {
 259         return;
 260     }
 261     QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
 262         DeviceState *qdev = kid->child;
 263         PCIDevice *pdev = PCI_DEVICE(qdev);
 264         int slot = PCI_SLOT(pdev->devfn);
 265
 266         if (acpi_pcihp_pc_no_hotplug(s, pdev)) {
 267             s->acpi_pcihp_pci_status[bsel].hotplug_enable &= ~(1U << slot);
 268         }
 269     }
 270 }
 271
 272 static void acpi_pcihp_update(AcpiPciHpState *s)
 273 {
 274     int i;
 275
 276     for (i = 0; i < ACPI_PCIHP_MAX_HOTPLUG_BUS; ++i) {
 277         acpi_pcihp_update_hotplug_bus(s, i);
 278     }
 279 }
 280
 281 void acpi_pcihp_reset(AcpiPciHpState *s, bool acpihp_root_off)
 282 {
 283     if (acpihp_root_off) {
 284         acpi_pcihp_disable_root_bus();
 285     }
 286     acpi_set_pci_info();
 287     acpi_pcihp_update(s);
 288 }
 289
 290 #define ONBOARD_INDEX_MAX (16 * 1024 - 1)
 291
 292 void acpi_pcihp_device_pre_plug_cb(HotplugHandler *hotplug_dev,
 293                                    DeviceState *dev, Error **errp)
 294 {
 295     PCIDevice *pdev = PCI_DEVICE(dev);
 296
 297     /* Only hotplugged devices need the hotplug capability. */
 298     if (dev->hotplugged &&
 299         acpi_pcihp_get_bsel(pci_get_bus(pdev)) < 0) {
 300         error_setg(errp, "Unsupported bus. Bus doesn't have property '"
 301                    ACPI_PCIHP_PROP_BSEL "' set");
 302         return;
 303     }
 304
 305     /*
 306      * capped by systemd (see: udev-builtin-net_id.c)
 307      * as it's the only known user honor it to avoid users
 308      * misconfigure QEMU and then wonder why acpi-index doesn't work
 309      */
 310     if (pdev->acpi_index > ONBOARD_INDEX_MAX) {
 311         error_setg(errp, "acpi-index should be less or equal to %u",
 312                    ONBOARD_INDEX_MAX);
 313         return;
 314     }
 315
 316     /*
 317      * make sure that acpi-index is unique across all present PCI devices
 318      */
 319     if (pdev->acpi_index) {
 320         GSequence *used_indexes = pci_acpi_index_list();
 321
 322         if (g_sequence_lookup(used_indexes, GINT_TO_POINTER(pdev->acpi_index),
 323                               g_cmp_uint32, NULL)) {
 324             error_setg(errp, "a PCI device with acpi-index = %" PRIu32
 325                        " already exist", pdev->acpi_index);
 326             return;
 327         }
 328         g_sequence_insert_sorted(used_indexes,
 329                                  GINT_TO_POINTER(pdev->acpi_index),
 330                                  g_cmp_uint32, NULL);
 331     }
 332 }
 333
 334 void acpi_pcihp_device_plug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,
 335                                DeviceState *dev, Error **errp)
 336 {
 337     PCIDevice *pdev = PCI_DEVICE(dev);
 338     int slot = PCI_SLOT(pdev->devfn);
 339     int bsel;
 340
 341     /* Don't send event when device is enabled during qemu machine creation:
 342      * it is present on boot, no hotplug event is necessary. We do send an
 343      * event when the device is disabled later. */
 344     if (!dev->hotplugged) {
 345         /*
 346          * Overwrite the default hotplug handler with the ACPI PCI one
 347          * for cold plugged bridges only.
 348          */
 349         if (!s->legacy_piix &&
 350             object_dynamic_cast(OBJECT(dev), TYPE_PCI_BRIDGE)) {
 351             PCIBus *sec = pci_bridge_get_sec_bus(PCI_BRIDGE(pdev));
 352
 353             /* Remove all hot-plug handlers if hot-plug is disabled on slot */
 354             if (object_dynamic_cast(OBJECT(dev), TYPE_PCIE_SLOT) &&
 355                 !PCIE_SLOT(pdev)->hotplug) {
 356                 qbus_set_hotplug_handler(BUS(sec), NULL);
 357                 return;
 358             }
 359
 360             qbus_set_hotplug_handler(BUS(sec), OBJECT(hotplug_dev));
 361             /* We don't have to overwrite any other hotplug handler yet */
 362             assert(QLIST_EMPTY(&sec->child));
 363         }
 364
 365         return;
 366     }
 367
 368     bsel = acpi_pcihp_get_bsel(pci_get_bus(pdev));
 369     g_assert(bsel >= 0);
 370     s->acpi_pcihp_pci_status[bsel].up |= (1U << slot);
 371     acpi_send_event(DEVICE(hotplug_dev), ACPI_PCI_HOTPLUG_STATUS);
 372 }
 373
 374 void acpi_pcihp_device_unplug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,
 375                                  DeviceState *dev, Error **errp)
 376 {
 377     PCIDevice *pdev = PCI_DEVICE(dev);
 378
 379     trace_acpi_pci_unplug(PCI_SLOT(pdev->devfn),
 380                           acpi_pcihp_get_bsel(pci_get_bus(pdev)));
 381
 382     /*
 383      * clean up acpi-index so it could reused by another device
 384      */
 385     if (pdev->acpi_index) {
 386         GSequence *used_indexes = pci_acpi_index_list();
 387
 388         g_sequence_remove(g_sequence_lookup(used_indexes,
 389                           GINT_TO_POINTER(pdev->acpi_index),
 390                           g_cmp_uint32, NULL));
 391     }
 392
 393     qdev_unrealize(dev);
 394 }
 395
 396 void acpi_pcihp_device_unplug_request_cb(HotplugHandler *hotplug_dev,
 397                                          AcpiPciHpState *s, DeviceState *dev,
 398                                          Error **errp)
 399 {
 400     PCIDevice *pdev = PCI_DEVICE(dev);
 401     int slot = PCI_SLOT(pdev->devfn);
 402     int bsel = acpi_pcihp_get_bsel(pci_get_bus(pdev));
 403
 404     trace_acpi_pci_unplug_request(bsel, slot);
 405
 406     if (bsel < 0) {
 407         error_setg(errp, "Unsupported bus. Bus doesn't have property '"
 408                    ACPI_PCIHP_PROP_BSEL "' set");
 409         return;
 410     }
 411
 412     /*
 413      * pending_deleted_event is used by virtio-net failover to detect the
 414      * end of the unplug operation, the flag is set to false in
 415      * acpi_pcihp_eject_slot() when the operation is completed.
 416      */
 417     pdev->qdev.pending_deleted_event = true;
 418     s->acpi_pcihp_pci_status[bsel].down |= (1U << slot);
 419     acpi_send_event(DEVICE(hotplug_dev), ACPI_PCI_HOTPLUG_STATUS);
 420 }
 421
 422 static uint64_t pci_read(void *opaque, hwaddr addr, unsigned int size)
 423 {
 424     AcpiPciHpState *s = opaque;
 425     uint32_t val = 0;
 426     int bsel = s->hotplug_select;
 427
 428     if (bsel < 0 || bsel >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
 429         return 0;
 430     }
 431
 432     switch (addr) {
 433     case PCI_UP_BASE:
 434         val = s->acpi_pcihp_pci_status[bsel].up;
 435         if (!s->legacy_piix) {
 436             s->acpi_pcihp_pci_status[bsel].up = 0;
 437         }
 438         trace_acpi_pci_up_read(val);
 439         break;
 440     case PCI_DOWN_BASE:
 441         val = s->acpi_pcihp_pci_status[bsel].down;
 442         trace_acpi_pci_down_read(val);
 443         break;
 444     case PCI_EJ_BASE:
 445         trace_acpi_pci_features_read(val);
 446         break;
 447     case PCI_RMV_BASE:
 448         val = s->acpi_pcihp_pci_status[bsel].hotplug_enable;
 449         trace_acpi_pci_rmv_read(val);
 450         break;
 451     case PCI_SEL_BASE:
 452         val = s->hotplug_select;
 453         trace_acpi_pci_sel_read(val);
 454         break;
 455     case PCI_AIDX_BASE:
 456         val = s->acpi_index;
 457         s->acpi_index = 0;
 458         trace_acpi_pci_acpi_index_read(val);
 459         break;
 460     default:
 461         break;
 462     }
 463
 464     return val;
 465 }
 466
 467 static void pci_write(void *opaque, hwaddr addr, uint64_t data,
 468                       unsigned int size)
 469 {
 470     int slot;
 471     PCIBus *bus;
 472     BusChild *kid, *next;
 473     AcpiPciHpState *s = opaque;
 474
 475     s->acpi_index = 0;
 476     switch (addr) {
 477     case PCI_AIDX_BASE:
 478         /*
 479          * fetch acpi-index for specified slot so that follow up read from
 480          * PCI_AIDX_BASE can return it to guest
 481          */
 482         slot = ctz32(data);
 483
 484         if (s->hotplug_select >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
 485             break;
 486         }
 487
 488         bus = acpi_pcihp_find_hotplug_bus(s, s->hotplug_select);
 489         if (!bus) {
 490             break;
 491         }
 492         QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
 493             Object *o = OBJECT(kid->child);
 494             PCIDevice *dev = PCI_DEVICE(o);
 495             if (PCI_SLOT(dev->devfn) == slot) {
 496                 s->acpi_index = object_property_get_uint(o, "acpi-index", NULL);
 497                 break;
 498             }
 499         }
 500         trace_acpi_pci_acpi_index_write(s->hotplug_select, slot, s->acpi_index);
 501         break;
 502     case PCI_EJ_BASE:
 503         if (s->hotplug_select >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
 504             break;
 505         }
 506         acpi_pcihp_eject_slot(s, s->hotplug_select, data);
 507         trace_acpi_pci_ej_write(addr, data);
 508         break;
 509     case PCI_SEL_BASE:
 510         s->hotplug_select = s->legacy_piix ? ACPI_PCIHP_BSEL_DEFAULT : data;
 511         trace_acpi_pci_sel_write(addr, data);
 512     default:
 513         break;
 514     }
 515 }
 516
 517 static const MemoryRegionOps acpi_pcihp_io_ops = {
 518     .read = pci_read,
 519     .write = pci_write,
 520     .endianness = DEVICE_LITTLE_ENDIAN,
 521     .valid = {
 522         .min_access_size = 4,
 523         .max_access_size = 4,
 524     },
 525 };
 526
 527 void acpi_pcihp_init(Object *owner, AcpiPciHpState *s, PCIBus *root_bus,
 528                      MemoryRegion *address_space_io, bool bridges_enabled,
 529                      uint16_t io_base)
 530 {
 531     s->io_len = ACPI_PCIHP_SIZE;
 532     s->io_base = io_base;
 533
 534     s->root = root_bus;
 535     s->legacy_piix = !bridges_enabled;
 536
 537     memory_region_init_io(&s->io, owner, &acpi_pcihp_io_ops, s,
 538                           "acpi-pci-hotplug", s->io_len);
 539     memory_region_add_subregion(address_space_io, s->io_base, &s->io);
 540
 541     object_property_add_uint16_ptr(owner, ACPI_PCIHP_IO_BASE_PROP, &s->io_base,
 542                                    OBJ_PROP_FLAG_READ);
 543     object_property_add_uint16_ptr(owner, ACPI_PCIHP_IO_LEN_PROP, &s->io_len,
 544                                    OBJ_PROP_FLAG_READ);
 545 }
 546
 547 bool vmstate_acpi_pcihp_use_acpi_index(void *opaque, int version_id)
 548 {
 549      AcpiPciHpState *s = opaque;
 550      return s->acpi_index;
 551 }
 552
 553 const VMStateDescription vmstate_acpi_pcihp_pci_status = {
 554     .name = "acpi_pcihp_pci_status",
 555     .version_id = 1,
 556     .minimum_version_id = 1,
 557     .fields = (VMStateField[]) {
 558         VMSTATE_UINT32(up, AcpiPciHpPciStatus),
 559         VMSTATE_UINT32(down, AcpiPciHpPciStatus),
 560         VMSTATE_END_OF_LIST()
 561     }
 562 };