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     static bool root_hp_disabled;
 132     Object *host = acpi_get_i386_pci_host();
 133     PCIBus *bus;
 134
 135     if (root_hp_disabled) {
 136         return;
 137     }
 138
 139     bus = PCI_HOST_BRIDGE(host)->bus;
 140     if (bus) {
 141         /* setting the hotplug handler to NULL makes the bus non-hotpluggable */
 142         qbus_set_hotplug_handler(BUS(bus), NULL);
 143     }
 144     root_hp_disabled = true;
 145     return;
 146 }
 147
 148 static void acpi_pcihp_test_hotplug_bus(PCIBus *bus, void *opaque)
 149 {
 150     AcpiPciHpFind *find = opaque;
 151     if (find->bsel == acpi_pcihp_get_bsel(bus)) {
 152         find->bus = bus;
 153     }
 154 }
 155
 156 static PCIBus *acpi_pcihp_find_hotplug_bus(AcpiPciHpState *s, int bsel)
 157 {
 158     AcpiPciHpFind find = { .bsel = bsel, .bus = NULL };
 159
 160     if (bsel < 0) {
 161         return NULL;
 162     }
 163
 164     pci_for_each_bus(s->root, acpi_pcihp_test_hotplug_bus, &find);
 165
 166     /* Make bsel 0 eject root bus if bsel property is not set,
 167      * for compatibility with non acpi setups.
 168      * TODO: really needed?
 169      */
 170     if (!bsel && !find.bus) {
 171         find.bus = s->root;
 172     }
 173
 174     /*
 175      * Check if find.bus is actually hotpluggable. If bsel is set to
 176      * NULL for example on the root bus in order to make it
 177      * non-hotpluggable, find.bus will match the root bus when bsel
 178      * is 0. See acpi_pcihp_test_hotplug_bus() above. Since the
 179      * bus is not hotpluggable however, we should not select the bus.
 180      * Instead, we should set find.bus to NULL in that case. In the check
 181      * below, we generalize this case for all buses, not just the root bus.
 182      * The callers of this function check for a null return value and
 183      * handle them appropriately.
 184      */
 185     if (find.bus && !qbus_is_hotpluggable(BUS(find.bus))) {
 186         find.bus = NULL;
 187     }
 188     return find.bus;
 189 }
 190
 191 static bool acpi_pcihp_pc_no_hotplug(AcpiPciHpState *s, PCIDevice *dev)
 192 {
 193     PCIDeviceClass *pc = PCI_DEVICE_GET_CLASS(dev);
 194     DeviceClass *dc = DEVICE_GET_CLASS(dev);
 195     /*
 196      * ACPI doesn't allow hotplug of bridge devices.  Don't allow
 197      * hot-unplug of bridge devices unless they were added by hotplug
 198      * (and so, not described by acpi).
 199      */
 200     return (pc->is_bridge && !dev->qdev.hotplugged) || !dc->hotpluggable;
 201 }
 202
 203 static void acpi_pcihp_eject_slot(AcpiPciHpState *s, unsigned bsel, unsigned slots)
 204 {
 205     HotplugHandler *hotplug_ctrl;
 206     BusChild *kid, *next;
 207     int slot = ctz32(slots);
 208     PCIBus *bus = acpi_pcihp_find_hotplug_bus(s, bsel);
 209
 210     trace_acpi_pci_eject_slot(bsel, slot);
 211
 212     if (!bus || slot > 31) {
 213         return;
 214     }
 215
 216     /* Mark request as complete */
 217     s->acpi_pcihp_pci_status[bsel].down &= ~(1U << slot);
 218     s->acpi_pcihp_pci_status[bsel].up &= ~(1U << slot);
 219
 220     QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
 221         DeviceState *qdev = kid->child;
 222         PCIDevice *dev = PCI_DEVICE(qdev);
 223         if (PCI_SLOT(dev->devfn) == slot) {
 224             if (!acpi_pcihp_pc_no_hotplug(s, dev)) {
 225                 hotplug_ctrl = qdev_get_hotplug_handler(qdev);
 226                 hotplug_handler_unplug(hotplug_ctrl, qdev, &error_abort);
 227                 object_unparent(OBJECT(qdev));
 228             }
 229         }
 230     }
 231 }
 232
 233 static void acpi_pcihp_update_hotplug_bus(AcpiPciHpState *s, int bsel)
 234 {
 235     BusChild *kid, *next;
 236     PCIBus *bus = acpi_pcihp_find_hotplug_bus(s, bsel);
 237
 238     /* Execute any pending removes during reset */
 239     while (s->acpi_pcihp_pci_status[bsel].down) {
 240         acpi_pcihp_eject_slot(s, bsel, s->acpi_pcihp_pci_status[bsel].down);
 241     }
 242
 243     s->acpi_pcihp_pci_status[bsel].hotplug_enable = ~0;
 244
 245     if (!bus) {
 246         return;
 247     }
 248     QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
 249         DeviceState *qdev = kid->child;
 250         PCIDevice *pdev = PCI_DEVICE(qdev);
 251         int slot = PCI_SLOT(pdev->devfn);
 252
 253         if (acpi_pcihp_pc_no_hotplug(s, pdev)) {
 254             s->acpi_pcihp_pci_status[bsel].hotplug_enable &= ~(1U << slot);
 255         }
 256     }
 257 }
 258
 259 static void acpi_pcihp_update(AcpiPciHpState *s)
 260 {
 261     int i;
 262
 263     for (i = 0; i < ACPI_PCIHP_MAX_HOTPLUG_BUS; ++i) {
 264         acpi_pcihp_update_hotplug_bus(s, i);
 265     }
 266 }
 267
 268 void acpi_pcihp_reset(AcpiPciHpState *s, bool acpihp_root_off)
 269 {
 270     if (acpihp_root_off) {
 271         acpi_pcihp_disable_root_bus();
 272     }
 273     acpi_set_pci_info();
 274     acpi_pcihp_update(s);
 275 }
 276
 277 #define ONBOARD_INDEX_MAX (16 * 1024 - 1)
 278
 279 void acpi_pcihp_device_pre_plug_cb(HotplugHandler *hotplug_dev,
 280                                    DeviceState *dev, Error **errp)
 281 {
 282     PCIDevice *pdev = PCI_DEVICE(dev);
 283
 284     /* Only hotplugged devices need the hotplug capability. */
 285     if (dev->hotplugged &&
 286         acpi_pcihp_get_bsel(pci_get_bus(pdev)) < 0) {
 287         error_setg(errp, "Unsupported bus. Bus doesn't have property '"
 288                    ACPI_PCIHP_PROP_BSEL "' set");
 289         return;
 290     }
 291
 292     /*
 293      * capped by systemd (see: udev-builtin-net_id.c)
 294      * as it's the only known user honor it to avoid users
 295      * misconfigure QEMU and then wonder why acpi-index doesn't work
 296      */
 297     if (pdev->acpi_index > ONBOARD_INDEX_MAX) {
 298         error_setg(errp, "acpi-index should be less or equal to %u",
 299                    ONBOARD_INDEX_MAX);
 300         return;
 301     }
 302
 303     /*
 304      * make sure that acpi-index is unique across all present PCI devices
 305      */
 306     if (pdev->acpi_index) {
 307         GSequence *used_indexes = pci_acpi_index_list();
 308
 309         if (g_sequence_lookup(used_indexes, GINT_TO_POINTER(pdev->acpi_index),
 310                               g_cmp_uint32, NULL)) {
 311             error_setg(errp, "a PCI device with acpi-index = %" PRIu32
 312                        " already exist", pdev->acpi_index);
 313             return;
 314         }
 315         g_sequence_insert_sorted(used_indexes,
 316                                  GINT_TO_POINTER(pdev->acpi_index),
 317                                  g_cmp_uint32, NULL);
 318     }
 319 }
 320
 321 void acpi_pcihp_device_plug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,
 322                                DeviceState *dev, Error **errp)
 323 {
 324     PCIDevice *pdev = PCI_DEVICE(dev);
 325     int slot = PCI_SLOT(pdev->devfn);
 326     int bsel;
 327
 328     /* Don't send event when device is enabled during qemu machine creation:
 329      * it is present on boot, no hotplug event is necessary. We do send an
 330      * event when the device is disabled later. */
 331     if (!dev->hotplugged) {
 332         /*
 333          * Overwrite the default hotplug handler with the ACPI PCI one
 334          * for cold plugged bridges only.
 335          */
 336         if (!s->legacy_piix &&
 337             object_dynamic_cast(OBJECT(dev), TYPE_PCI_BRIDGE)) {
 338             PCIBus *sec = pci_bridge_get_sec_bus(PCI_BRIDGE(pdev));
 339
 340             /* Remove all hot-plug handlers if hot-plug is disabled on slot */
 341             if (object_dynamic_cast(OBJECT(dev), TYPE_PCIE_SLOT) &&
 342                 !PCIE_SLOT(pdev)->hotplug) {
 343                 qbus_set_hotplug_handler(BUS(sec), NULL);
 344                 return;
 345             }
 346
 347             qbus_set_hotplug_handler(BUS(sec), OBJECT(hotplug_dev));
 348             /* We don't have to overwrite any other hotplug handler yet */
 349             assert(QLIST_EMPTY(&sec->child));
 350         }
 351
 352         return;
 353     }
 354
 355     bsel = acpi_pcihp_get_bsel(pci_get_bus(pdev));
 356     g_assert(bsel >= 0);
 357     s->acpi_pcihp_pci_status[bsel].up |= (1U << slot);
 358     acpi_send_event(DEVICE(hotplug_dev), ACPI_PCI_HOTPLUG_STATUS);
 359 }
 360
 361 void acpi_pcihp_device_unplug_cb(HotplugHandler *hotplug_dev, AcpiPciHpState *s,
 362                                  DeviceState *dev, Error **errp)
 363 {
 364     PCIDevice *pdev = PCI_DEVICE(dev);
 365
 366     trace_acpi_pci_unplug(PCI_SLOT(pdev->devfn),
 367                           acpi_pcihp_get_bsel(pci_get_bus(pdev)));
 368
 369     /*
 370      * clean up acpi-index so it could reused by another device
 371      */
 372     if (pdev->acpi_index) {
 373         GSequence *used_indexes = pci_acpi_index_list();
 374
 375         g_sequence_remove(g_sequence_lookup(used_indexes,
 376                           GINT_TO_POINTER(pdev->acpi_index),
 377                           g_cmp_uint32, NULL));
 378     }
 379
 380     qdev_unrealize(dev);
 381 }
 382
 383 void acpi_pcihp_device_unplug_request_cb(HotplugHandler *hotplug_dev,
 384                                          AcpiPciHpState *s, DeviceState *dev,
 385                                          Error **errp)
 386 {
 387     PCIDevice *pdev = PCI_DEVICE(dev);
 388     int slot = PCI_SLOT(pdev->devfn);
 389     int bsel = acpi_pcihp_get_bsel(pci_get_bus(pdev));
 390
 391     trace_acpi_pci_unplug_request(bsel, slot);
 392
 393     if (bsel < 0) {
 394         error_setg(errp, "Unsupported bus. Bus doesn't have property '"
 395                    ACPI_PCIHP_PROP_BSEL "' set");
 396         return;
 397     }
 398
 399     s->acpi_pcihp_pci_status[bsel].down |= (1U << slot);
 400     acpi_send_event(DEVICE(hotplug_dev), ACPI_PCI_HOTPLUG_STATUS);
 401 }
 402
 403 static uint64_t pci_read(void *opaque, hwaddr addr, unsigned int size)
 404 {
 405     AcpiPciHpState *s = opaque;
 406     uint32_t val = 0;
 407     int bsel = s->hotplug_select;
 408
 409     if (bsel < 0 || bsel >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
 410         return 0;
 411     }
 412
 413     switch (addr) {
 414     case PCI_UP_BASE:
 415         val = s->acpi_pcihp_pci_status[bsel].up;
 416         if (!s->legacy_piix) {
 417             s->acpi_pcihp_pci_status[bsel].up = 0;
 418         }
 419         trace_acpi_pci_up_read(val);
 420         break;
 421     case PCI_DOWN_BASE:
 422         val = s->acpi_pcihp_pci_status[bsel].down;
 423         trace_acpi_pci_down_read(val);
 424         break;
 425     case PCI_EJ_BASE:
 426         trace_acpi_pci_features_read(val);
 427         break;
 428     case PCI_RMV_BASE:
 429         val = s->acpi_pcihp_pci_status[bsel].hotplug_enable;
 430         trace_acpi_pci_rmv_read(val);
 431         break;
 432     case PCI_SEL_BASE:
 433         val = s->hotplug_select;
 434         trace_acpi_pci_sel_read(val);
 435         break;
 436     case PCI_AIDX_BASE:
 437         val = s->acpi_index;
 438         s->acpi_index = 0;
 439         trace_acpi_pci_acpi_index_read(val);
 440         break;
 441     default:
 442         break;
 443     }
 444
 445     return val;
 446 }
 447
 448 static void pci_write(void *opaque, hwaddr addr, uint64_t data,
 449                       unsigned int size)
 450 {
 451     int slot;
 452     PCIBus *bus;
 453     BusChild *kid, *next;
 454     AcpiPciHpState *s = opaque;
 455
 456     s->acpi_index = 0;
 457     switch (addr) {
 458     case PCI_AIDX_BASE:
 459         /*
 460          * fetch acpi-index for specified slot so that follow up read from
 461          * PCI_AIDX_BASE can return it to guest
 462          */
 463         slot = ctz32(data);
 464
 465         if (s->hotplug_select >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
 466             break;
 467         }
 468
 469         bus = acpi_pcihp_find_hotplug_bus(s, s->hotplug_select);
 470         QTAILQ_FOREACH_SAFE(kid, &bus->qbus.children, sibling, next) {
 471             Object *o = OBJECT(kid->child);
 472             PCIDevice *dev = PCI_DEVICE(o);
 473             if (PCI_SLOT(dev->devfn) == slot) {
 474                 s->acpi_index = object_property_get_uint(o, "acpi-index", NULL);
 475                 break;
 476             }
 477         }
 478         trace_acpi_pci_acpi_index_write(s->hotplug_select, slot, s->acpi_index);
 479         break;
 480     case PCI_EJ_BASE:
 481         if (s->hotplug_select >= ACPI_PCIHP_MAX_HOTPLUG_BUS) {
 482             break;
 483         }
 484         acpi_pcihp_eject_slot(s, s->hotplug_select, data);
 485         trace_acpi_pci_ej_write(addr, data);
 486         break;
 487     case PCI_SEL_BASE:
 488         s->hotplug_select = s->legacy_piix ? ACPI_PCIHP_BSEL_DEFAULT : data;
 489         trace_acpi_pci_sel_write(addr, data);
 490     default:
 491         break;
 492     }
 493 }
 494
 495 static const MemoryRegionOps acpi_pcihp_io_ops = {
 496     .read = pci_read,
 497     .write = pci_write,
 498     .endianness = DEVICE_LITTLE_ENDIAN,
 499     .valid = {
 500         .min_access_size = 4,
 501         .max_access_size = 4,
 502     },
 503 };
 504
 505 void acpi_pcihp_init(Object *owner, AcpiPciHpState *s, PCIBus *root_bus,
 506                      MemoryRegion *address_space_io, bool bridges_enabled,
 507                      uint16_t io_base)
 508 {
 509     s->io_len = ACPI_PCIHP_SIZE;
 510     s->io_base = io_base;
 511
 512     s->root = root_bus;
 513     s->legacy_piix = !bridges_enabled;
 514
 515     memory_region_init_io(&s->io, owner, &acpi_pcihp_io_ops, s,
 516                           "acpi-pci-hotplug", s->io_len);
 517     memory_region_add_subregion(address_space_io, s->io_base, &s->io);
 518
 519     object_property_add_uint16_ptr(owner, ACPI_PCIHP_IO_BASE_PROP, &s->io_base,
 520                                    OBJ_PROP_FLAG_READ);
 521     object_property_add_uint16_ptr(owner, ACPI_PCIHP_IO_LEN_PROP, &s->io_len,
 522                                    OBJ_PROP_FLAG_READ);
 523 }
 524
 525 bool vmstate_acpi_pcihp_use_acpi_index(void *opaque, int version_id)
 526 {
 527      AcpiPciHpState *s = opaque;
 528      return s->acpi_index;
 529 }
 530
 531 const VMStateDescription vmstate_acpi_pcihp_pci_status = {
 532     .name = "acpi_pcihp_pci_status",
 533     .version_id = 1,
 534     .minimum_version_id = 1,
 535     .fields = (VMStateField[]) {
 536         VMSTATE_UINT32(up, AcpiPciHpPciStatus),
 537         VMSTATE_UINT32(down, AcpiPciHpPciStatus),
 538         VMSTATE_END_OF_LIST()
 539     }
 540 };