drivers/vfio/pci/vfio_pci_core.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
   4  *     Author: Alex Williamson <alex.williamson@redhat.com>
   5  *
   6  * Derived from original vfio:
   7  * Copyright 2010 Cisco Systems, Inc.  All rights reserved.
   8  * Author: Tom Lyon, pugs@cisco.com
   9  */
  10
  11 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  12
  13 #include <linux/device.h>
  14 #include <linux/eventfd.h>
  15 #include <linux/file.h>
  16 #include <linux/interrupt.h>
  17 #include <linux/iommu.h>
  18 #include <linux/module.h>
  19 #include <linux/mutex.h>
  20 #include <linux/notifier.h>
  21 #include <linux/pci.h>
  22 #include <linux/pm_runtime.h>
  23 #include <linux/slab.h>
  24 #include <linux/types.h>
  25 #include <linux/uaccess.h>
  26 #include <linux/vgaarb.h>
  27 #include <linux/nospec.h>
  28 #include <linux/sched/mm.h>
  29
  30 #include <linux/vfio_pci_core.h>
  31
  32 #define DRIVER_AUTHOR   "Alex Williamson <alex.williamson@redhat.com>"
  33 #define DRIVER_DESC "core driver for VFIO based PCI devices"
  34
  35 static bool nointxmask;
  36 static bool disable_vga;
  37 static bool disable_idle_d3;
  38
  39 static inline bool vfio_vga_disabled(void)
  40 {
  41 #ifdef CONFIG_VFIO_PCI_VGA
  42         return disable_vga;
  43 #else
  44         return true;
  45 #endif
  46 }
  47
  48 /*
  49  * Our VGA arbiter participation is limited since we don't know anything
  50  * about the device itself.  However, if the device is the only VGA device
  51  * downstream of a bridge and VFIO VGA support is disabled, then we can
  52  * safely return legacy VGA IO and memory as not decoded since the user
  53  * has no way to get to it and routing can be disabled externally at the
  54  * bridge.
  55  */
  56 static unsigned int vfio_pci_set_decode(struct pci_dev *pdev, bool single_vga)
  57 {
  58         struct pci_dev *tmp = NULL;
  59         unsigned char max_busnr;
  60         unsigned int decodes;
  61
  62         if (single_vga || !vfio_vga_disabled() || pci_is_root_bus(pdev->bus))
  63                 return VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM |
  64                        VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
  65
  66         max_busnr = pci_bus_max_busnr(pdev->bus);
  67         decodes = VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM;
  68
  69         while ((tmp = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, tmp)) != NULL) {
  70                 if (tmp == pdev ||
  71                     pci_domain_nr(tmp->bus) != pci_domain_nr(pdev->bus) ||
  72                     pci_is_root_bus(tmp->bus))
  73                         continue;
  74
  75                 if (tmp->bus->number >= pdev->bus->number &&
  76                     tmp->bus->number <= max_busnr) {
  77                         pci_dev_put(tmp);
  78                         decodes |= VGA_RSRC_LEGACY_IO | VGA_RSRC_LEGACY_MEM;
  79                         break;
  80                 }
  81         }
  82
  83         return decodes;
  84 }
  85
  86 static void vfio_pci_probe_mmaps(struct vfio_pci_core_device *vdev)
  87 {
  88         struct resource *res;
  89         int i;
  90         struct vfio_pci_dummy_resource *dummy_res;
  91
  92         for (i = 0; i < PCI_STD_NUM_BARS; i++) {
  93                 int bar = i + PCI_STD_RESOURCES;
  94
  95                 res = &vdev->pdev->resource[bar];
  96
  97                 if (!IS_ENABLED(CONFIG_VFIO_PCI_MMAP))
  98                         goto no_mmap;
  99
 100                 if (!(res->flags & IORESOURCE_MEM))
 101                         goto no_mmap;
 102
 103                 /*
 104                  * The PCI core shouldn't set up a resource with a
 105                  * type but zero size. But there may be bugs that
 106                  * cause us to do that.
 107                  */
 108                 if (!resource_size(res))
 109                         goto no_mmap;
 110
 111                 if (resource_size(res) >= PAGE_SIZE) {
 112                         vdev->bar_mmap_supported[bar] = true;
 113                         continue;
 114                 }
 115
 116                 if (!(res->start & ~PAGE_MASK)) {
 117                         /*
 118                          * Add a dummy resource to reserve the remainder
 119                          * of the exclusive page in case that hot-add
 120                          * device's bar is assigned into it.
 121                          */
 122                         dummy_res = kzalloc(sizeof(*dummy_res), GFP_KERNEL);
 123                         if (dummy_res == NULL)
 124                                 goto no_mmap;
 125
 126                         dummy_res->resource.name = "vfio sub-page reserved";
 127                         dummy_res->resource.start = res->end + 1;
 128                         dummy_res->resource.end = res->start + PAGE_SIZE - 1;
 129                         dummy_res->resource.flags = res->flags;
 130                         if (request_resource(res->parent,
 131                                                 &dummy_res->resource)) {
 132                                 kfree(dummy_res);
 133                                 goto no_mmap;
 134                         }
 135                         dummy_res->index = bar;
 136                         list_add(&dummy_res->res_next,
 137                                         &vdev->dummy_resources_list);
 138                         vdev->bar_mmap_supported[bar] = true;
 139                         continue;
 140                 }
 141                 /*
 142                  * Here we don't handle the case when the BAR is not page
 143                  * aligned because we can't expect the BAR will be
 144                  * assigned into the same location in a page in guest
 145                  * when we passthrough the BAR. And it's hard to access
 146                  * this BAR in userspace because we have no way to get
 147                  * the BAR's location in a page.
 148                  */
 149 no_mmap:
 150                 vdev->bar_mmap_supported[bar] = false;
 151         }
 152 }
 153
 154 struct vfio_pci_group_info;
 155 static bool vfio_pci_dev_set_try_reset(struct vfio_device_set *dev_set);
 156 static int vfio_pci_dev_set_hot_reset(struct vfio_device_set *dev_set,
 157                                       struct vfio_pci_group_info *groups);
 158
 159 /*
 160  * INTx masking requires the ability to disable INTx signaling via PCI_COMMAND
 161  * _and_ the ability detect when the device is asserting INTx via PCI_STATUS.
 162  * If a device implements the former but not the latter we would typically
 163  * expect broken_intx_masking be set and require an exclusive interrupt.
 164  * However since we do have control of the device's ability to assert INTx,
 165  * we can instead pretend that the device does not implement INTx, virtualizing
 166  * the pin register to report zero and maintaining DisINTx set on the host.
 167  */
 168 static bool vfio_pci_nointx(struct pci_dev *pdev)
 169 {
 170         switch (pdev->vendor) {
 171         case PCI_VENDOR_ID_INTEL:
 172                 switch (pdev->device) {
 173                 /* All i40e (XL710/X710/XXV710) 10/20/25/40GbE NICs */
 174                 case 0x1572:
 175                 case 0x1574:
 176                 case 0x1580 ... 0x1581:
 177                 case 0x1583 ... 0x158b:
 178                 case 0x37d0 ... 0x37d2:
 179                 /* X550 */
 180                 case 0x1563:
 181                         return true;
 182                 default:
 183                         return false;
 184                 }
 185         }
 186
 187         return false;
 188 }
 189
 190 static void vfio_pci_probe_power_state(struct vfio_pci_core_device *vdev)
 191 {
 192         struct pci_dev *pdev = vdev->pdev;
 193         u16 pmcsr;
 194
 195         if (!pdev->pm_cap)
 196                 return;
 197
 198         pci_read_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, &pmcsr);
 199
 200         vdev->needs_pm_restore = !(pmcsr & PCI_PM_CTRL_NO_SOFT_RESET);
 201 }
 202
 203 /*
 204  * pci_set_power_state() wrapper handling devices which perform a soft reset on
 205  * D3->D0 transition.  Save state prior to D0/1/2->D3, stash it on the vdev,
 206  * restore when returned to D0.  Saved separately from pci_saved_state for use
 207  * by PM capability emulation and separately from pci_dev internal saved state
 208  * to avoid it being overwritten and consumed around other resets.
 209  */
 210 int vfio_pci_set_power_state(struct vfio_pci_core_device *vdev, pci_power_t state)
 211 {
 212         struct pci_dev *pdev = vdev->pdev;
 213         bool needs_restore = false, needs_save = false;
 214         int ret;
 215
 216         if (vdev->needs_pm_restore) {
 217                 if (pdev->current_state < PCI_D3hot && state >= PCI_D3hot) {
 218                         pci_save_state(pdev);
 219                         needs_save = true;
 220                 }
 221
 222                 if (pdev->current_state >= PCI_D3hot && state <= PCI_D0)
 223                         needs_restore = true;
 224         }
 225
 226         ret = pci_set_power_state(pdev, state);
 227
 228         if (!ret) {
 229                 /* D3 might be unsupported via quirk, skip unless in D3 */
 230                 if (needs_save && pdev->current_state >= PCI_D3hot) {
 231                         vdev->pm_save = pci_store_saved_state(pdev);
 232                 } else if (needs_restore) {
 233                         pci_load_and_free_saved_state(pdev, &vdev->pm_save);
 234                         pci_restore_state(pdev);
 235                 }
 236         }
 237
 238         return ret;
 239 }
 240
 241 int vfio_pci_core_enable(struct vfio_pci_core_device *vdev)
 242 {
 243         struct pci_dev *pdev = vdev->pdev;
 244         int ret;
 245         u16 cmd;
 246         u8 msix_pos;
 247
 248         vfio_pci_set_power_state(vdev, PCI_D0);
 249
 250         /* Don't allow our initial saved state to include busmaster */
 251         pci_clear_master(pdev);
 252
 253         ret = pci_enable_device(pdev);
 254         if (ret)
 255                 return ret;
 256
 257         /* If reset fails because of the device lock, fail this path entirely */
 258         ret = pci_try_reset_function(pdev);
 259         if (ret == -EAGAIN) {
 260                 pci_disable_device(pdev);
 261                 return ret;
 262         }
 263
 264         vdev->reset_works = !ret;
 265         pci_save_state(pdev);
 266         vdev->pci_saved_state = pci_store_saved_state(pdev);
 267         if (!vdev->pci_saved_state)
 268                 pci_dbg(pdev, "%s: Couldn't store saved state\n", __func__);
 269
 270         if (likely(!nointxmask)) {
 271                 if (vfio_pci_nointx(pdev)) {
 272                         pci_info(pdev, "Masking broken INTx support\n");
 273                         vdev->nointx = true;
 274                         pci_intx(pdev, 0);
 275                 } else
 276                         vdev->pci_2_3 = pci_intx_mask_supported(pdev);
 277         }
 278
 279         pci_read_config_word(pdev, PCI_COMMAND, &cmd);
 280         if (vdev->pci_2_3 && (cmd & PCI_COMMAND_INTX_DISABLE)) {
 281                 cmd &= ~PCI_COMMAND_INTX_DISABLE;
 282                 pci_write_config_word(pdev, PCI_COMMAND, cmd);
 283         }
 284
 285         ret = vfio_config_init(vdev);
 286         if (ret) {
 287                 kfree(vdev->pci_saved_state);
 288                 vdev->pci_saved_state = NULL;
 289                 pci_disable_device(pdev);
 290                 return ret;
 291         }
 292
 293         msix_pos = pdev->msix_cap;
 294         if (msix_pos) {
 295                 u16 flags;
 296                 u32 table;
 297
 298                 pci_read_config_word(pdev, msix_pos + PCI_MSIX_FLAGS, &flags);
 299                 pci_read_config_dword(pdev, msix_pos + PCI_MSIX_TABLE, &table);
 300
 301                 vdev->msix_bar = table & PCI_MSIX_TABLE_BIR;
 302                 vdev->msix_offset = table & PCI_MSIX_TABLE_OFFSET;
 303                 vdev->msix_size = ((flags & PCI_MSIX_FLAGS_QSIZE) + 1) * 16;
 304         } else
 305                 vdev->msix_bar = 0xFF;
 306
 307         if (!vfio_vga_disabled() && vfio_pci_is_vga(pdev))
 308                 vdev->has_vga = true;
 309
 310
 311         return 0;
 312 }
 313 EXPORT_SYMBOL_GPL(vfio_pci_core_enable);
 314
 315 void vfio_pci_core_disable(struct vfio_pci_core_device *vdev)
 316 {
 317         struct pci_dev *pdev = vdev->pdev;
 318         struct vfio_pci_dummy_resource *dummy_res, *tmp;
 319         struct vfio_pci_ioeventfd *ioeventfd, *ioeventfd_tmp;
 320         int i, bar;
 321
 322         /* For needs_reset */
 323         lockdep_assert_held(&vdev->vdev.dev_set->lock);
 324
 325         /* Stop the device from further DMA */
 326         pci_clear_master(pdev);
 327
 328         vfio_pci_set_irqs_ioctl(vdev, VFIO_IRQ_SET_DATA_NONE |
 329                                 VFIO_IRQ_SET_ACTION_TRIGGER,
 330                                 vdev->irq_type, 0, 0, NULL);
 331
 332         /* Device closed, don't need mutex here */
 333         list_for_each_entry_safe(ioeventfd, ioeventfd_tmp,
 334                                  &vdev->ioeventfds_list, next) {
 335                 vfio_virqfd_disable(&ioeventfd->virqfd);
 336                 list_del(&ioeventfd->next);
 337                 kfree(ioeventfd);
 338         }
 339         vdev->ioeventfds_nr = 0;
 340
 341         vdev->virq_disabled = false;
 342
 343         for (i = 0; i < vdev->num_regions; i++)
 344                 vdev->region[i].ops->release(vdev, &vdev->region[i]);
 345
 346         vdev->num_regions = 0;
 347         kfree(vdev->region);
 348         vdev->region = NULL; /* don't krealloc a freed pointer */
 349
 350         vfio_config_free(vdev);
 351
 352         for (i = 0; i < PCI_STD_NUM_BARS; i++) {
 353                 bar = i + PCI_STD_RESOURCES;
 354                 if (!vdev->barmap[bar])
 355                         continue;
 356                 pci_iounmap(pdev, vdev->barmap[bar]);
 357                 pci_release_selected_regions(pdev, 1 << bar);
 358                 vdev->barmap[bar] = NULL;
 359         }
 360
 361         list_for_each_entry_safe(dummy_res, tmp,
 362                                  &vdev->dummy_resources_list, res_next) {
 363                 list_del(&dummy_res->res_next);
 364                 release_resource(&dummy_res->resource);
 365                 kfree(dummy_res);
 366         }
 367
 368         vdev->needs_reset = true;
 369
 370         /*
 371          * If we have saved state, restore it.  If we can reset the device,
 372          * even better.  Resetting with current state seems better than
 373          * nothing, but saving and restoring current state without reset
 374          * is just busy work.
 375          */
 376         if (pci_load_and_free_saved_state(pdev, &vdev->pci_saved_state)) {
 377                 pci_info(pdev, "%s: Couldn't reload saved state\n", __func__);
 378
 379                 if (!vdev->reset_works)
 380                         goto out;
 381
 382                 pci_save_state(pdev);
 383         }
 384
 385         /*
 386          * Disable INTx and MSI, presumably to avoid spurious interrupts
 387          * during reset.  Stolen from pci_reset_function()
 388          */
 389         pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
 390
 391         /*
 392          * Try to get the locks ourselves to prevent a deadlock. The
 393          * success of this is dependent on being able to lock the device,
 394          * which is not always possible.
 395          * We can not use the "try" reset interface here, which will
 396          * overwrite the previously restored configuration information.
 397          */
 398         if (vdev->reset_works && pci_dev_trylock(pdev)) {
 399                 if (!__pci_reset_function_locked(pdev))
 400                         vdev->needs_reset = false;
 401                 pci_dev_unlock(pdev);
 402         }
 403
 404         pci_restore_state(pdev);
 405 out:
 406         pci_disable_device(pdev);
 407
 408         if (!vfio_pci_dev_set_try_reset(vdev->vdev.dev_set) && !disable_idle_d3)
 409                 vfio_pci_set_power_state(vdev, PCI_D3hot);
 410 }
 411 EXPORT_SYMBOL_GPL(vfio_pci_core_disable);
 412
 413 static struct vfio_pci_core_device *get_pf_vdev(struct vfio_pci_core_device *vdev)
 414 {
 415         struct pci_dev *physfn = pci_physfn(vdev->pdev);
 416         struct vfio_device *pf_dev;
 417
 418         if (!vdev->pdev->is_virtfn)
 419                 return NULL;
 420
 421         pf_dev = vfio_device_get_from_dev(&physfn->dev);
 422         if (!pf_dev)
 423                 return NULL;
 424
 425         if (pci_dev_driver(physfn) != pci_dev_driver(vdev->pdev)) {
 426                 vfio_device_put(pf_dev);
 427                 return NULL;
 428         }
 429
 430         return container_of(pf_dev, struct vfio_pci_core_device, vdev);
 431 }
 432
 433 static void vfio_pci_vf_token_user_add(struct vfio_pci_core_device *vdev, int val)
 434 {
 435         struct vfio_pci_core_device *pf_vdev = get_pf_vdev(vdev);
 436
 437         if (!pf_vdev)
 438                 return;
 439
 440         mutex_lock(&pf_vdev->vf_token->lock);
 441         pf_vdev->vf_token->users += val;
 442         WARN_ON(pf_vdev->vf_token->users < 0);
 443         mutex_unlock(&pf_vdev->vf_token->lock);
 444
 445         vfio_device_put(&pf_vdev->vdev);
 446 }
 447
 448 void vfio_pci_core_close_device(struct vfio_device *core_vdev)
 449 {
 450         struct vfio_pci_core_device *vdev =
 451                 container_of(core_vdev, struct vfio_pci_core_device, vdev);
 452
 453         vfio_pci_vf_token_user_add(vdev, -1);
 454         vfio_spapr_pci_eeh_release(vdev->pdev);
 455         vfio_pci_core_disable(vdev);
 456
 457         mutex_lock(&vdev->igate);
 458         if (vdev->err_trigger) {
 459                 eventfd_ctx_put(vdev->err_trigger);
 460                 vdev->err_trigger = NULL;
 461         }
 462         if (vdev->req_trigger) {
 463                 eventfd_ctx_put(vdev->req_trigger);
 464                 vdev->req_trigger = NULL;
 465         }
 466         mutex_unlock(&vdev->igate);
 467 }
 468 EXPORT_SYMBOL_GPL(vfio_pci_core_close_device);
 469
 470 void vfio_pci_core_finish_enable(struct vfio_pci_core_device *vdev)
 471 {
 472         vfio_pci_probe_mmaps(vdev);
 473         vfio_spapr_pci_eeh_open(vdev->pdev);
 474         vfio_pci_vf_token_user_add(vdev, 1);
 475 }
 476 EXPORT_SYMBOL_GPL(vfio_pci_core_finish_enable);
 477
 478 static int vfio_pci_get_irq_count(struct vfio_pci_core_device *vdev, int irq_type)
 479 {
 480         if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) {
 481                 u8 pin;
 482
 483                 if (!IS_ENABLED(CONFIG_VFIO_PCI_INTX) ||
 484                     vdev->nointx || vdev->pdev->is_virtfn)
 485                         return 0;
 486
 487                 pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN, &pin);
 488
 489                 return pin ? 1 : 0;
 490         } else if (irq_type == VFIO_PCI_MSI_IRQ_INDEX) {
 491                 u8 pos;
 492                 u16 flags;
 493
 494                 pos = vdev->pdev->msi_cap;
 495                 if (pos) {
 496                         pci_read_config_word(vdev->pdev,
 497                                              pos + PCI_MSI_FLAGS, &flags);
 498                         return 1 << ((flags & PCI_MSI_FLAGS_QMASK) >> 1);
 499                 }
 500         } else if (irq_type == VFIO_PCI_MSIX_IRQ_INDEX) {
 501                 u8 pos;
 502                 u16 flags;
 503
 504                 pos = vdev->pdev->msix_cap;
 505                 if (pos) {
 506                         pci_read_config_word(vdev->pdev,
 507                                              pos + PCI_MSIX_FLAGS, &flags);
 508
 509                         return (flags & PCI_MSIX_FLAGS_QSIZE) + 1;
 510                 }
 511         } else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX) {
 512                 if (pci_is_pcie(vdev->pdev))
 513                         return 1;
 514         } else if (irq_type == VFIO_PCI_REQ_IRQ_INDEX) {
 515                 return 1;
 516         }
 517
 518         return 0;
 519 }
 520
 521 static int vfio_pci_count_devs(struct pci_dev *pdev, void *data)
 522 {
 523         (*(int *)data)++;
 524         return 0;
 525 }
 526
 527 struct vfio_pci_fill_info {
 528         int max;
 529         int cur;
 530         struct vfio_pci_dependent_device *devices;
 531 };
 532
 533 static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data)
 534 {
 535         struct vfio_pci_fill_info *fill = data;
 536         struct iommu_group *iommu_group;
 537
 538         if (fill->cur == fill->max)
 539                 return -EAGAIN; /* Something changed, try again */
 540
 541         iommu_group = iommu_group_get(&pdev->dev);
 542         if (!iommu_group)
 543                 return -EPERM; /* Cannot reset non-isolated devices */
 544
 545         fill->devices[fill->cur].group_id = iommu_group_id(iommu_group);
 546         fill->devices[fill->cur].segment = pci_domain_nr(pdev->bus);
 547         fill->devices[fill->cur].bus = pdev->bus->number;
 548         fill->devices[fill->cur].devfn = pdev->devfn;
 549         fill->cur++;
 550         iommu_group_put(iommu_group);
 551         return 0;
 552 }
 553
 554 struct vfio_pci_group_info {
 555         int count;
 556         struct vfio_group **groups;
 557 };
 558
 559 static bool vfio_pci_dev_below_slot(struct pci_dev *pdev, struct pci_slot *slot)
 560 {
 561         for (; pdev; pdev = pdev->bus->self)
 562                 if (pdev->bus == slot->bus)
 563                         return (pdev->slot == slot);
 564         return false;
 565 }
 566
 567 struct vfio_pci_walk_info {
 568         int (*fn)(struct pci_dev *, void *data);
 569         void *data;
 570         struct pci_dev *pdev;
 571         bool slot;
 572         int ret;
 573 };
 574
 575 static int vfio_pci_walk_wrapper(struct pci_dev *pdev, void *data)
 576 {
 577         struct vfio_pci_walk_info *walk = data;
 578
 579         if (!walk->slot || vfio_pci_dev_below_slot(pdev, walk->pdev->slot))
 580                 walk->ret = walk->fn(pdev, walk->data);
 581
 582         return walk->ret;
 583 }
 584
 585 static int vfio_pci_for_each_slot_or_bus(struct pci_dev *pdev,
 586                                          int (*fn)(struct pci_dev *,
 587                                                    void *data), void *data,
 588                                          bool slot)
 589 {
 590         struct vfio_pci_walk_info walk = {
 591                 .fn = fn, .data = data, .pdev = pdev, .slot = slot, .ret = 0,
 592         };
 593
 594         pci_walk_bus(pdev->bus, vfio_pci_walk_wrapper, &walk);
 595
 596         return walk.ret;
 597 }
 598
 599 static int msix_mmappable_cap(struct vfio_pci_core_device *vdev,
 600                               struct vfio_info_cap *caps)
 601 {
 602         struct vfio_info_cap_header header = {
 603                 .id = VFIO_REGION_INFO_CAP_MSIX_MAPPABLE,
 604                 .version = 1
 605         };
 606
 607         return vfio_info_add_capability(caps, &header, sizeof(header));
 608 }
 609
 610 int vfio_pci_register_dev_region(struct vfio_pci_core_device *vdev,
 611                                  unsigned int type, unsigned int subtype,
 612                                  const struct vfio_pci_regops *ops,
 613                                  size_t size, u32 flags, void *data)
 614 {
 615         struct vfio_pci_region *region;
 616
 617         region = krealloc(vdev->region,
 618                           (vdev->num_regions + 1) * sizeof(*region),
 619                           GFP_KERNEL);
 620         if (!region)
 621                 return -ENOMEM;
 622
 623         vdev->region = region;
 624         vdev->region[vdev->num_regions].type = type;
 625         vdev->region[vdev->num_regions].subtype = subtype;
 626         vdev->region[vdev->num_regions].ops = ops;
 627         vdev->region[vdev->num_regions].size = size;
 628         vdev->region[vdev->num_regions].flags = flags;
 629         vdev->region[vdev->num_regions].data = data;
 630
 631         vdev->num_regions++;
 632
 633         return 0;
 634 }
 635 EXPORT_SYMBOL_GPL(vfio_pci_register_dev_region);
 636
 637 long vfio_pci_core_ioctl(struct vfio_device *core_vdev, unsigned int cmd,
 638                 unsigned long arg)
 639 {
 640         struct vfio_pci_core_device *vdev =
 641                 container_of(core_vdev, struct vfio_pci_core_device, vdev);
 642         unsigned long minsz;
 643
 644         if (cmd == VFIO_DEVICE_GET_INFO) {
 645                 struct vfio_device_info info;
 646                 struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
 647                 unsigned long capsz;
 648                 int ret;
 649
 650                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 651
 652                 /* For backward compatibility, cannot require this */
 653                 capsz = offsetofend(struct vfio_iommu_type1_info, cap_offset);
 654
 655                 if (copy_from_user(&info, (void __user *)arg, minsz))
 656                         return -EFAULT;
 657
 658                 if (info.argsz < minsz)
 659                         return -EINVAL;
 660
 661                 if (info.argsz >= capsz) {
 662                         minsz = capsz;
 663                         info.cap_offset = 0;
 664                 }
 665
 666                 info.flags = VFIO_DEVICE_FLAGS_PCI;
 667
 668                 if (vdev->reset_works)
 669                         info.flags |= VFIO_DEVICE_FLAGS_RESET;
 670
 671                 info.num_regions = VFIO_PCI_NUM_REGIONS + vdev->num_regions;
 672                 info.num_irqs = VFIO_PCI_NUM_IRQS;
 673
 674                 ret = vfio_pci_info_zdev_add_caps(vdev, &caps);
 675                 if (ret && ret != -ENODEV) {
 676                         pci_warn(vdev->pdev, "Failed to setup zPCI info capabilities\n");
 677                         return ret;
 678                 }
 679
 680                 if (caps.size) {
 681                         info.flags |= VFIO_DEVICE_FLAGS_CAPS;
 682                         if (info.argsz < sizeof(info) + caps.size) {
 683                                 info.argsz = sizeof(info) + caps.size;
 684                         } else {
 685                                 vfio_info_cap_shift(&caps, sizeof(info));
 686                                 if (copy_to_user((void __user *)arg +
 687                                                   sizeof(info), caps.buf,
 688                                                   caps.size)) {
 689                                         kfree(caps.buf);
 690                                         return -EFAULT;
 691                                 }
 692                                 info.cap_offset = sizeof(info);
 693                         }
 694
 695                         kfree(caps.buf);
 696                 }
 697
 698                 return copy_to_user((void __user *)arg, &info, minsz) ?
 699                         -EFAULT : 0;
 700
 701         } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
 702                 struct pci_dev *pdev = vdev->pdev;
 703                 struct vfio_region_info info;
 704                 struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
 705                 int i, ret;
 706
 707                 minsz = offsetofend(struct vfio_region_info, offset);
 708
 709                 if (copy_from_user(&info, (void __user *)arg, minsz))
 710                         return -EFAULT;
 711
 712                 if (info.argsz < minsz)
 713                         return -EINVAL;
 714
 715                 switch (info.index) {
 716                 case VFIO_PCI_CONFIG_REGION_INDEX:
 717                         info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 718                         info.size = pdev->cfg_size;
 719                         info.flags = VFIO_REGION_INFO_FLAG_READ |
 720                                      VFIO_REGION_INFO_FLAG_WRITE;
 721                         break;
 722                 case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
 723                         info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 724                         info.size = pci_resource_len(pdev, info.index);
 725                         if (!info.size) {
 726                                 info.flags = 0;
 727                                 break;
 728                         }
 729
 730                         info.flags = VFIO_REGION_INFO_FLAG_READ |
 731                                      VFIO_REGION_INFO_FLAG_WRITE;
 732                         if (vdev->bar_mmap_supported[info.index]) {
 733                                 info.flags |= VFIO_REGION_INFO_FLAG_MMAP;
 734                                 if (info.index == vdev->msix_bar) {
 735                                         ret = msix_mmappable_cap(vdev, &caps);
 736                                         if (ret)
 737                                                 return ret;
 738                                 }
 739                         }
 740
 741                         break;
 742                 case VFIO_PCI_ROM_REGION_INDEX:
 743                 {
 744                         void __iomem *io;
 745                         size_t size;
 746                         u16 cmd;
 747
 748                         info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 749                         info.flags = 0;
 750
 751                         /* Report the BAR size, not the ROM size */
 752                         info.size = pci_resource_len(pdev, info.index);
 753                         if (!info.size) {
 754                                 /* Shadow ROMs appear as PCI option ROMs */
 755                                 if (pdev->resource[PCI_ROM_RESOURCE].flags &
 756                                                         IORESOURCE_ROM_SHADOW)
 757                                         info.size = 0x20000;
 758                                 else
 759                                         break;
 760                         }
 761
 762                         /*
 763                          * Is it really there?  Enable memory decode for
 764                          * implicit access in pci_map_rom().
 765                          */
 766                         cmd = vfio_pci_memory_lock_and_enable(vdev);
 767                         io = pci_map_rom(pdev, &size);
 768                         if (io) {
 769                                 info.flags = VFIO_REGION_INFO_FLAG_READ;
 770                                 pci_unmap_rom(pdev, io);
 771                         } else {
 772                                 info.size = 0;
 773                         }
 774                         vfio_pci_memory_unlock_and_restore(vdev, cmd);
 775
 776                         break;
 777                 }
 778                 case VFIO_PCI_VGA_REGION_INDEX:
 779                         if (!vdev->has_vga)
 780                                 return -EINVAL;
 781
 782                         info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 783                         info.size = 0xc0000;
 784                         info.flags = VFIO_REGION_INFO_FLAG_READ |
 785                                      VFIO_REGION_INFO_FLAG_WRITE;
 786
 787                         break;
 788                 default:
 789                 {
 790                         struct vfio_region_info_cap_type cap_type = {
 791                                         .header.id = VFIO_REGION_INFO_CAP_TYPE,
 792                                         .header.version = 1 };
 793
 794                         if (info.index >=
 795                             VFIO_PCI_NUM_REGIONS + vdev->num_regions)
 796                                 return -EINVAL;
 797                         info.index = array_index_nospec(info.index,
 798                                                         VFIO_PCI_NUM_REGIONS +
 799                                                         vdev->num_regions);
 800
 801                         i = info.index - VFIO_PCI_NUM_REGIONS;
 802
 803                         info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 804                         info.size = vdev->region[i].size;
 805                         info.flags = vdev->region[i].flags;
 806
 807                         cap_type.type = vdev->region[i].type;
 808                         cap_type.subtype = vdev->region[i].subtype;
 809
 810                         ret = vfio_info_add_capability(&caps, &cap_type.header,
 811                                                        sizeof(cap_type));
 812                         if (ret)
 813                                 return ret;
 814
 815                         if (vdev->region[i].ops->add_capability) {
 816                                 ret = vdev->region[i].ops->add_capability(vdev,
 817                                                 &vdev->region[i], &caps);
 818                                 if (ret)
 819                                         return ret;
 820                         }
 821                 }
 822                 }
 823
 824                 if (caps.size) {
 825                         info.flags |= VFIO_REGION_INFO_FLAG_CAPS;
 826                         if (info.argsz < sizeof(info) + caps.size) {
 827                                 info.argsz = sizeof(info) + caps.size;
 828                                 info.cap_offset = 0;
 829                         } else {
 830                                 vfio_info_cap_shift(&caps, sizeof(info));
 831                                 if (copy_to_user((void __user *)arg +
 832                                                   sizeof(info), caps.buf,
 833                                                   caps.size)) {
 834                                         kfree(caps.buf);
 835                                         return -EFAULT;
 836                                 }
 837                                 info.cap_offset = sizeof(info);
 838                         }
 839
 840                         kfree(caps.buf);
 841                 }
 842
 843                 return copy_to_user((void __user *)arg, &info, minsz) ?
 844                         -EFAULT : 0;
 845
 846         } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
 847                 struct vfio_irq_info info;
 848
 849                 minsz = offsetofend(struct vfio_irq_info, count);
 850
 851                 if (copy_from_user(&info, (void __user *)arg, minsz))
 852                         return -EFAULT;
 853
 854                 if (info.argsz < minsz || info.index >= VFIO_PCI_NUM_IRQS)
 855                         return -EINVAL;
 856
 857                 switch (info.index) {
 858                 case VFIO_PCI_INTX_IRQ_INDEX ... VFIO_PCI_MSIX_IRQ_INDEX:
 859                 case VFIO_PCI_REQ_IRQ_INDEX:
 860                         break;
 861                 case VFIO_PCI_ERR_IRQ_INDEX:
 862                         if (pci_is_pcie(vdev->pdev))
 863                                 break;
 864                         fallthrough;
 865                 default:
 866                         return -EINVAL;
 867                 }
 868
 869                 info.flags = VFIO_IRQ_INFO_EVENTFD;
 870
 871                 info.count = vfio_pci_get_irq_count(vdev, info.index);
 872
 873                 if (info.index == VFIO_PCI_INTX_IRQ_INDEX)
 874                         info.flags |= (VFIO_IRQ_INFO_MASKABLE |
 875                                        VFIO_IRQ_INFO_AUTOMASKED);
 876                 else
 877                         info.flags |= VFIO_IRQ_INFO_NORESIZE;
 878
 879                 return copy_to_user((void __user *)arg, &info, minsz) ?
 880                         -EFAULT : 0;
 881
 882         } else if (cmd == VFIO_DEVICE_SET_IRQS) {
 883                 struct vfio_irq_set hdr;
 884                 u8 *data = NULL;
 885                 int max, ret = 0;
 886                 size_t data_size = 0;
 887
 888                 minsz = offsetofend(struct vfio_irq_set, count);
 889
 890                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 891                         return -EFAULT;
 892
 893                 max = vfio_pci_get_irq_count(vdev, hdr.index);
 894
 895                 ret = vfio_set_irqs_validate_and_prepare(&hdr, max,
 896                                                  VFIO_PCI_NUM_IRQS, &data_size);
 897                 if (ret)
 898                         return ret;
 899
 900                 if (data_size) {
 901                         data = memdup_user((void __user *)(arg + minsz),
 902                                             data_size);
 903                         if (IS_ERR(data))
 904                                 return PTR_ERR(data);
 905                 }
 906
 907                 mutex_lock(&vdev->igate);
 908
 909                 ret = vfio_pci_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
 910                                               hdr.start, hdr.count, data);
 911
 912                 mutex_unlock(&vdev->igate);
 913                 kfree(data);
 914
 915                 return ret;
 916
 917         } else if (cmd == VFIO_DEVICE_RESET) {
 918                 int ret;
 919
 920                 if (!vdev->reset_works)
 921                         return -EINVAL;
 922
 923                 vfio_pci_zap_and_down_write_memory_lock(vdev);
 924                 ret = pci_try_reset_function(vdev->pdev);
 925                 up_write(&vdev->memory_lock);
 926
 927                 return ret;
 928
 929         } else if (cmd == VFIO_DEVICE_GET_PCI_HOT_RESET_INFO) {
 930                 struct vfio_pci_hot_reset_info hdr;
 931                 struct vfio_pci_fill_info fill = { 0 };
 932                 struct vfio_pci_dependent_device *devices = NULL;
 933                 bool slot = false;
 934                 int ret = 0;
 935
 936                 minsz = offsetofend(struct vfio_pci_hot_reset_info, count);
 937
 938                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 939                         return -EFAULT;
 940
 941                 if (hdr.argsz < minsz)
 942                         return -EINVAL;
 943
 944                 hdr.flags = 0;
 945
 946                 /* Can we do a slot or bus reset or neither? */
 947                 if (!pci_probe_reset_slot(vdev->pdev->slot))
 948                         slot = true;
 949                 else if (pci_probe_reset_bus(vdev->pdev->bus))
 950                         return -ENODEV;
 951
 952                 /* How many devices are affected? */
 953                 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
 954                                                     vfio_pci_count_devs,
 955                                                     &fill.max, slot);
 956                 if (ret)
 957                         return ret;
 958
 959                 WARN_ON(!fill.max); /* Should always be at least one */
 960
 961                 /*
 962                  * If there's enough space, fill it now, otherwise return
 963                  * -ENOSPC and the number of devices affected.
 964                  */
 965                 if (hdr.argsz < sizeof(hdr) + (fill.max * sizeof(*devices))) {
 966                         ret = -ENOSPC;
 967                         hdr.count = fill.max;
 968                         goto reset_info_exit;
 969                 }
 970
 971                 devices = kcalloc(fill.max, sizeof(*devices), GFP_KERNEL);
 972                 if (!devices)
 973                         return -ENOMEM;
 974
 975                 fill.devices = devices;
 976
 977                 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
 978                                                     vfio_pci_fill_devs,
 979                                                     &fill, slot);
 980
 981                 /*
 982                  * If a device was removed between counting and filling,
 983                  * we may come up short of fill.max.  If a device was
 984                  * added, we'll have a return of -EAGAIN above.
 985                  */
 986                 if (!ret)
 987                         hdr.count = fill.cur;
 988
 989 reset_info_exit:
 990                 if (copy_to_user((void __user *)arg, &hdr, minsz))
 991                         ret = -EFAULT;
 992
 993                 if (!ret) {
 994                         if (copy_to_user((void __user *)(arg + minsz), devices,
 995                                          hdr.count * sizeof(*devices)))
 996                                 ret = -EFAULT;
 997                 }
 998
 999                 kfree(devices);
1000                 return ret;
1001
1002         } else if (cmd == VFIO_DEVICE_PCI_HOT_RESET) {
1003                 struct vfio_pci_hot_reset hdr;
1004                 int32_t *group_fds;
1005                 struct vfio_group **groups;
1006                 struct vfio_pci_group_info info;
1007                 bool slot = false;
1008                 int group_idx, count = 0, ret = 0;
1009
1010                 minsz = offsetofend(struct vfio_pci_hot_reset, count);
1011
1012                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
1013                         return -EFAULT;
1014
1015                 if (hdr.argsz < minsz || hdr.flags)
1016                         return -EINVAL;
1017
1018                 /* Can we do a slot or bus reset or neither? */
1019                 if (!pci_probe_reset_slot(vdev->pdev->slot))
1020                         slot = true;
1021                 else if (pci_probe_reset_bus(vdev->pdev->bus))
1022                         return -ENODEV;
1023
1024                 /*
1025                  * We can't let userspace give us an arbitrarily large
1026                  * buffer to copy, so verify how many we think there
1027                  * could be.  Note groups can have multiple devices so
1028                  * one group per device is the max.
1029                  */
1030                 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
1031                                                     vfio_pci_count_devs,
1032                                                     &count, slot);
1033                 if (ret)
1034                         return ret;
1035
1036                 /* Somewhere between 1 and count is OK */
1037                 if (!hdr.count || hdr.count > count)
1038                         return -EINVAL;
1039
1040                 group_fds = kcalloc(hdr.count, sizeof(*group_fds), GFP_KERNEL);
1041                 groups = kcalloc(hdr.count, sizeof(*groups), GFP_KERNEL);
1042                 if (!group_fds || !groups) {
1043                         kfree(group_fds);
1044                         kfree(groups);
1045                         return -ENOMEM;
1046                 }
1047
1048                 if (copy_from_user(group_fds, (void __user *)(arg + minsz),
1049                                    hdr.count * sizeof(*group_fds))) {
1050                         kfree(group_fds);
1051                         kfree(groups);
1052                         return -EFAULT;
1053                 }
1054
1055                 /*
1056                  * For each group_fd, get the group through the vfio external
1057                  * user interface and store the group and iommu ID.  This
1058                  * ensures the group is held across the reset.
1059                  */
1060                 for (group_idx = 0; group_idx < hdr.count; group_idx++) {
1061                         struct vfio_group *group;
1062                         struct fd f = fdget(group_fds[group_idx]);
1063                         if (!f.file) {
1064                                 ret = -EBADF;
1065                                 break;
1066                         }
1067
1068                         group = vfio_group_get_external_user(f.file);
1069                         fdput(f);
1070                         if (IS_ERR(group)) {
1071                                 ret = PTR_ERR(group);
1072                                 break;
1073                         }
1074
1075                         groups[group_idx] = group;
1076                 }
1077
1078                 kfree(group_fds);
1079
1080                 /* release reference to groups on error */
1081                 if (ret)
1082                         goto hot_reset_release;
1083
1084                 info.count = hdr.count;
1085                 info.groups = groups;
1086
1087                 ret = vfio_pci_dev_set_hot_reset(vdev->vdev.dev_set, &info);
1088
1089 hot_reset_release:
1090                 for (group_idx--; group_idx >= 0; group_idx--)
1091                         vfio_group_put_external_user(groups[group_idx]);
1092
1093                 kfree(groups);
1094                 return ret;
1095         } else if (cmd == VFIO_DEVICE_IOEVENTFD) {
1096                 struct vfio_device_ioeventfd ioeventfd;
1097                 int count;
1098
1099                 minsz = offsetofend(struct vfio_device_ioeventfd, fd);
1100
1101                 if (copy_from_user(&ioeventfd, (void __user *)arg, minsz))
1102                         return -EFAULT;
1103
1104                 if (ioeventfd.argsz < minsz)
1105                         return -EINVAL;
1106
1107                 if (ioeventfd.flags & ~VFIO_DEVICE_IOEVENTFD_SIZE_MASK)
1108                         return -EINVAL;
1109
1110                 count = ioeventfd.flags & VFIO_DEVICE_IOEVENTFD_SIZE_MASK;
1111
1112                 if (hweight8(count) != 1 || ioeventfd.fd < -1)
1113                         return -EINVAL;
1114
1115                 return vfio_pci_ioeventfd(vdev, ioeventfd.offset,
1116                                           ioeventfd.data, count, ioeventfd.fd);
1117         } else if (cmd == VFIO_DEVICE_FEATURE) {
1118                 struct vfio_device_feature feature;
1119                 uuid_t uuid;
1120
1121                 minsz = offsetofend(struct vfio_device_feature, flags);
1122
1123                 if (copy_from_user(&feature, (void __user *)arg, minsz))
1124                         return -EFAULT;
1125
1126                 if (feature.argsz < minsz)
1127                         return -EINVAL;
1128
1129                 /* Check unknown flags */
1130                 if (feature.flags & ~(VFIO_DEVICE_FEATURE_MASK |
1131                                       VFIO_DEVICE_FEATURE_SET |
1132                                       VFIO_DEVICE_FEATURE_GET |
1133                                       VFIO_DEVICE_FEATURE_PROBE))
1134                         return -EINVAL;
1135
1136                 /* GET & SET are mutually exclusive except with PROBE */
1137                 if (!(feature.flags & VFIO_DEVICE_FEATURE_PROBE) &&
1138                     (feature.flags & VFIO_DEVICE_FEATURE_SET) &&
1139                     (feature.flags & VFIO_DEVICE_FEATURE_GET))
1140                         return -EINVAL;
1141
1142                 switch (feature.flags & VFIO_DEVICE_FEATURE_MASK) {
1143                 case VFIO_DEVICE_FEATURE_PCI_VF_TOKEN:
1144                         if (!vdev->vf_token)
1145                                 return -ENOTTY;
1146
1147                         /*
1148                          * We do not support GET of the VF Token UUID as this
1149                          * could expose the token of the previous device user.
1150                          */
1151                         if (feature.flags & VFIO_DEVICE_FEATURE_GET)
1152                                 return -EINVAL;
1153
1154                         if (feature.flags & VFIO_DEVICE_FEATURE_PROBE)
1155                                 return 0;
1156
1157                         /* Don't SET unless told to do so */
1158                         if (!(feature.flags & VFIO_DEVICE_FEATURE_SET))
1159                                 return -EINVAL;
1160
1161                         if (feature.argsz < minsz + sizeof(uuid))
1162                                 return -EINVAL;
1163
1164                         if (copy_from_user(&uuid, (void __user *)(arg + minsz),
1165                                            sizeof(uuid)))
1166                                 return -EFAULT;
1167
1168                         mutex_lock(&vdev->vf_token->lock);
1169                         uuid_copy(&vdev->vf_token->uuid, &uuid);
1170                         mutex_unlock(&vdev->vf_token->lock);
1171
1172                         return 0;
1173                 default:
1174                         return -ENOTTY;
1175                 }
1176         }
1177
1178         return -ENOTTY;
1179 }
1180 EXPORT_SYMBOL_GPL(vfio_pci_core_ioctl);
1181
1182 static ssize_t vfio_pci_rw(struct vfio_pci_core_device *vdev, char __user *buf,
1183                            size_t count, loff_t *ppos, bool iswrite)
1184 {
1185         unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
1186
1187         if (index >= VFIO_PCI_NUM_REGIONS + vdev->num_regions)
1188                 return -EINVAL;
1189
1190         switch (index) {
1191         case VFIO_PCI_CONFIG_REGION_INDEX:
1192                 return vfio_pci_config_rw(vdev, buf, count, ppos, iswrite);
1193
1194         case VFIO_PCI_ROM_REGION_INDEX:
1195                 if (iswrite)
1196                         return -EINVAL;
1197                 return vfio_pci_bar_rw(vdev, buf, count, ppos, false);
1198
1199         case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
1200                 return vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite);
1201
1202         case VFIO_PCI_VGA_REGION_INDEX:
1203                 return vfio_pci_vga_rw(vdev, buf, count, ppos, iswrite);
1204         default:
1205                 index -= VFIO_PCI_NUM_REGIONS;
1206                 return vdev->region[index].ops->rw(vdev, buf,
1207                                                    count, ppos, iswrite);
1208         }
1209
1210         return -EINVAL;
1211 }
1212
1213 ssize_t vfio_pci_core_read(struct vfio_device *core_vdev, char __user *buf,
1214                 size_t count, loff_t *ppos)
1215 {
1216         struct vfio_pci_core_device *vdev =
1217                 container_of(core_vdev, struct vfio_pci_core_device, vdev);
1218
1219         if (!count)
1220                 return 0;
1221
1222         return vfio_pci_rw(vdev, buf, count, ppos, false);
1223 }
1224 EXPORT_SYMBOL_GPL(vfio_pci_core_read);
1225
1226 ssize_t vfio_pci_core_write(struct vfio_device *core_vdev, const char __user *buf,
1227                 size_t count, loff_t *ppos)
1228 {
1229         struct vfio_pci_core_device *vdev =
1230                 container_of(core_vdev, struct vfio_pci_core_device, vdev);
1231
1232         if (!count)
1233                 return 0;
1234
1235         return vfio_pci_rw(vdev, (char __user *)buf, count, ppos, true);
1236 }
1237 EXPORT_SYMBOL_GPL(vfio_pci_core_write);
1238
1239 /* Return 1 on zap and vma_lock acquired, 0 on contention (only with @try) */
1240 static int vfio_pci_zap_and_vma_lock(struct vfio_pci_core_device *vdev, bool try)
1241 {
1242         struct vfio_pci_mmap_vma *mmap_vma, *tmp;
1243
1244         /*
1245          * Lock ordering:
1246          * vma_lock is nested under mmap_lock for vm_ops callback paths.
1247          * The memory_lock semaphore is used by both code paths calling
1248          * into this function to zap vmas and the vm_ops.fault callback
1249          * to protect the memory enable state of the device.
1250          *
1251          * When zapping vmas we need to maintain the mmap_lock => vma_lock
1252          * ordering, which requires using vma_lock to walk vma_list to
1253          * acquire an mm, then dropping vma_lock to get the mmap_lock and
1254          * reacquiring vma_lock.  This logic is derived from similar
1255          * requirements in uverbs_user_mmap_disassociate().
1256          *
1257          * mmap_lock must always be the top-level lock when it is taken.
1258          * Therefore we can only hold the memory_lock write lock when
1259          * vma_list is empty, as we'd need to take mmap_lock to clear
1260          * entries.  vma_list can only be guaranteed empty when holding
1261          * vma_lock, thus memory_lock is nested under vma_lock.
1262          *
1263          * This enables the vm_ops.fault callback to acquire vma_lock,
1264          * followed by memory_lock read lock, while already holding
1265          * mmap_lock without risk of deadlock.
1266          */
1267         while (1) {
1268                 struct mm_struct *mm = NULL;
1269
1270                 if (try) {
1271                         if (!mutex_trylock(&vdev->vma_lock))
1272                                 return 0;
1273                 } else {
1274                         mutex_lock(&vdev->vma_lock);
1275                 }
1276                 while (!list_empty(&vdev->vma_list)) {
1277                         mmap_vma = list_first_entry(&vdev->vma_list,
1278                                                     struct vfio_pci_mmap_vma,
1279                                                     vma_next);
1280                         mm = mmap_vma->vma->vm_mm;
1281                         if (mmget_not_zero(mm))
1282                                 break;
1283
1284                         list_del(&mmap_vma->vma_next);
1285                         kfree(mmap_vma);
1286                         mm = NULL;
1287                 }
1288                 if (!mm)
1289                         return 1;
1290                 mutex_unlock(&vdev->vma_lock);
1291
1292                 if (try) {
1293                         if (!mmap_read_trylock(mm)) {
1294                                 mmput(mm);
1295                                 return 0;
1296                         }
1297                 } else {
1298                         mmap_read_lock(mm);
1299                 }
1300                 if (try) {
1301                         if (!mutex_trylock(&vdev->vma_lock)) {
1302                                 mmap_read_unlock(mm);
1303                                 mmput(mm);
1304                                 return 0;
1305                         }
1306                 } else {
1307                         mutex_lock(&vdev->vma_lock);
1308                 }
1309                 list_for_each_entry_safe(mmap_vma, tmp,
1310                                          &vdev->vma_list, vma_next) {
1311                         struct vm_area_struct *vma = mmap_vma->vma;
1312
1313                         if (vma->vm_mm != mm)
1314                                 continue;
1315
1316                         list_del(&mmap_vma->vma_next);
1317                         kfree(mmap_vma);
1318
1319                         zap_vma_ptes(vma, vma->vm_start,
1320                                      vma->vm_end - vma->vm_start);
1321                 }
1322                 mutex_unlock(&vdev->vma_lock);
1323                 mmap_read_unlock(mm);
1324                 mmput(mm);
1325         }
1326 }
1327
1328 void vfio_pci_zap_and_down_write_memory_lock(struct vfio_pci_core_device *vdev)
1329 {
1330         vfio_pci_zap_and_vma_lock(vdev, false);
1331         down_write(&vdev->memory_lock);
1332         mutex_unlock(&vdev->vma_lock);
1333 }
1334
1335 u16 vfio_pci_memory_lock_and_enable(struct vfio_pci_core_device *vdev)
1336 {
1337         u16 cmd;
1338
1339         down_write(&vdev->memory_lock);
1340         pci_read_config_word(vdev->pdev, PCI_COMMAND, &cmd);
1341         if (!(cmd & PCI_COMMAND_MEMORY))
1342                 pci_write_config_word(vdev->pdev, PCI_COMMAND,
1343                                       cmd | PCI_COMMAND_MEMORY);
1344
1345         return cmd;
1346 }
1347
1348 void vfio_pci_memory_unlock_and_restore(struct vfio_pci_core_device *vdev, u16 cmd)
1349 {
1350         pci_write_config_word(vdev->pdev, PCI_COMMAND, cmd);
1351         up_write(&vdev->memory_lock);
1352 }
1353
1354 /* Caller holds vma_lock */
1355 static int __vfio_pci_add_vma(struct vfio_pci_core_device *vdev,
1356                               struct vm_area_struct *vma)
1357 {
1358         struct vfio_pci_mmap_vma *mmap_vma;
1359
1360         mmap_vma = kmalloc(sizeof(*mmap_vma), GFP_KERNEL);
1361         if (!mmap_vma)
1362                 return -ENOMEM;
1363
1364         mmap_vma->vma = vma;
1365         list_add(&mmap_vma->vma_next, &vdev->vma_list);
1366
1367         return 0;
1368 }
1369
1370 /*
1371  * Zap mmaps on open so that we can fault them in on access and therefore
1372  * our vma_list only tracks mappings accessed since last zap.
1373  */
1374 static void vfio_pci_mmap_open(struct vm_area_struct *vma)
1375 {
1376         zap_vma_ptes(vma, vma->vm_start, vma->vm_end - vma->vm_start);
1377 }
1378
1379 static void vfio_pci_mmap_close(struct vm_area_struct *vma)
1380 {
1381         struct vfio_pci_core_device *vdev = vma->vm_private_data;
1382         struct vfio_pci_mmap_vma *mmap_vma;
1383
1384         mutex_lock(&vdev->vma_lock);
1385         list_for_each_entry(mmap_vma, &vdev->vma_list, vma_next) {
1386                 if (mmap_vma->vma == vma) {
1387                         list_del(&mmap_vma->vma_next);
1388                         kfree(mmap_vma);
1389                         break;
1390                 }
1391         }
1392         mutex_unlock(&vdev->vma_lock);
1393 }
1394
1395 static vm_fault_t vfio_pci_mmap_fault(struct vm_fault *vmf)
1396 {
1397         struct vm_area_struct *vma = vmf->vma;
1398         struct vfio_pci_core_device *vdev = vma->vm_private_data;
1399         struct vfio_pci_mmap_vma *mmap_vma;
1400         vm_fault_t ret = VM_FAULT_NOPAGE;
1401
1402         mutex_lock(&vdev->vma_lock);
1403         down_read(&vdev->memory_lock);
1404
1405         if (!__vfio_pci_memory_enabled(vdev)) {
1406                 ret = VM_FAULT_SIGBUS;
1407                 goto up_out;
1408         }
1409
1410         /*
1411          * We populate the whole vma on fault, so we need to test whether
1412          * the vma has already been mapped, such as for concurrent faults
1413          * to the same vma.  io_remap_pfn_range() will trigger a BUG_ON if
1414          * we ask it to fill the same range again.
1415          */
1416         list_for_each_entry(mmap_vma, &vdev->vma_list, vma_next) {
1417                 if (mmap_vma->vma == vma)
1418                         goto up_out;
1419         }
1420
1421         if (io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
1422                                vma->vm_end - vma->vm_start,
1423                                vma->vm_page_prot)) {
1424                 ret = VM_FAULT_SIGBUS;
1425                 zap_vma_ptes(vma, vma->vm_start, vma->vm_end - vma->vm_start);
1426                 goto up_out;
1427         }
1428
1429         if (__vfio_pci_add_vma(vdev, vma)) {
1430                 ret = VM_FAULT_OOM;
1431                 zap_vma_ptes(vma, vma->vm_start, vma->vm_end - vma->vm_start);
1432         }
1433
1434 up_out:
1435         up_read(&vdev->memory_lock);
1436         mutex_unlock(&vdev->vma_lock);
1437         return ret;
1438 }
1439
1440 static const struct vm_operations_struct vfio_pci_mmap_ops = {
1441         .open = vfio_pci_mmap_open,
1442         .close = vfio_pci_mmap_close,
1443         .fault = vfio_pci_mmap_fault,
1444 };
1445
1446 int vfio_pci_core_mmap(struct vfio_device *core_vdev, struct vm_area_struct *vma)
1447 {
1448         struct vfio_pci_core_device *vdev =
1449                 container_of(core_vdev, struct vfio_pci_core_device, vdev);
1450         struct pci_dev *pdev = vdev->pdev;
1451         unsigned int index;
1452         u64 phys_len, req_len, pgoff, req_start;
1453         int ret;
1454
1455         index = vma->vm_pgoff >> (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT);
1456
1457         if (index >= VFIO_PCI_NUM_REGIONS + vdev->num_regions)
1458                 return -EINVAL;
1459         if (vma->vm_end < vma->vm_start)
1460                 return -EINVAL;
1461         if ((vma->vm_flags & VM_SHARED) == 0)
1462                 return -EINVAL;
1463         if (index >= VFIO_PCI_NUM_REGIONS) {
1464                 int regnum = index - VFIO_PCI_NUM_REGIONS;
1465                 struct vfio_pci_region *region = vdev->region + regnum;
1466
1467                 if (region->ops && region->ops->mmap &&
1468                     (region->flags & VFIO_REGION_INFO_FLAG_MMAP))
1469                         return region->ops->mmap(vdev, region, vma);
1470                 return -EINVAL;
1471         }
1472         if (index >= VFIO_PCI_ROM_REGION_INDEX)
1473                 return -EINVAL;
1474         if (!vdev->bar_mmap_supported[index])
1475                 return -EINVAL;
1476
1477         phys_len = PAGE_ALIGN(pci_resource_len(pdev, index));
1478         req_len = vma->vm_end - vma->vm_start;
1479         pgoff = vma->vm_pgoff &
1480                 ((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
1481         req_start = pgoff << PAGE_SHIFT;
1482
1483         if (req_start + req_len > phys_len)
1484                 return -EINVAL;
1485
1486         /*
1487          * Even though we don't make use of the barmap for the mmap,
1488          * we need to request the region and the barmap tracks that.
1489          */
1490         if (!vdev->barmap[index]) {
1491                 ret = pci_request_selected_regions(pdev,
1492                                                    1 << index, "vfio-pci");
1493                 if (ret)
1494                         return ret;
1495
1496                 vdev->barmap[index] = pci_iomap(pdev, index, 0);
1497                 if (!vdev->barmap[index]) {
1498                         pci_release_selected_regions(pdev, 1 << index);
1499                         return -ENOMEM;
1500                 }
1501         }
1502
1503         vma->vm_private_data = vdev;
1504         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
1505         vma->vm_pgoff = (pci_resource_start(pdev, index) >> PAGE_SHIFT) + pgoff;
1506
1507         /*
1508          * See remap_pfn_range(), called from vfio_pci_fault() but we can't
1509          * change vm_flags within the fault handler.  Set them now.
1510          */
1511         vma->vm_flags |= VM_IO | VM_PFNMAP | VM_DONTEXPAND | VM_DONTDUMP;
1512         vma->vm_ops = &vfio_pci_mmap_ops;
1513
1514         return 0;
1515 }
1516 EXPORT_SYMBOL_GPL(vfio_pci_core_mmap);
1517
1518 void vfio_pci_core_request(struct vfio_device *core_vdev, unsigned int count)
1519 {
1520         struct vfio_pci_core_device *vdev =
1521                 container_of(core_vdev, struct vfio_pci_core_device, vdev);
1522         struct pci_dev *pdev = vdev->pdev;
1523
1524         mutex_lock(&vdev->igate);
1525
1526         if (vdev->req_trigger) {
1527                 if (!(count % 10))
1528                         pci_notice_ratelimited(pdev,
1529                                 "Relaying device request to user (#%u)\n",
1530                                 count);
1531                 eventfd_signal(vdev->req_trigger, 1);
1532         } else if (count == 0) {
1533                 pci_warn(pdev,
1534                         "No device request channel registered, blocked until released by user\n");
1535         }
1536
1537         mutex_unlock(&vdev->igate);
1538 }
1539 EXPORT_SYMBOL_GPL(vfio_pci_core_request);
1540
1541 static int vfio_pci_validate_vf_token(struct vfio_pci_core_device *vdev,
1542                                       bool vf_token, uuid_t *uuid)
1543 {
1544         /*
1545          * There's always some degree of trust or collaboration between SR-IOV
1546          * PF and VFs, even if just that the PF hosts the SR-IOV capability and
1547          * can disrupt VFs with a reset, but often the PF has more explicit
1548          * access to deny service to the VF or access data passed through the
1549          * VF.  We therefore require an opt-in via a shared VF token (UUID) to
1550          * represent this trust.  This both prevents that a VF driver might
1551          * assume the PF driver is a trusted, in-kernel driver, and also that
1552          * a PF driver might be replaced with a rogue driver, unknown to in-use
1553          * VF drivers.
1554          *
1555          * Therefore when presented with a VF, if the PF is a vfio device and
1556          * it is bound to the vfio-pci driver, the user needs to provide a VF
1557          * token to access the device, in the form of appending a vf_token to
1558          * the device name, for example:
1559          *
1560          * "0000:04:10.0 vf_token=bd8d9d2b-5a5f-4f5a-a211-f591514ba1f3"
1561          *
1562          * When presented with a PF which has VFs in use, the user must also
1563          * provide the current VF token to prove collaboration with existing
1564          * VF users.  If VFs are not in use, the VF token provided for the PF
1565          * device will act to set the VF token.
1566          *
1567          * If the VF token is provided but unused, an error is generated.
1568          */
1569         if (!vdev->pdev->is_virtfn && !vdev->vf_token && !vf_token)
1570                 return 0; /* No VF token provided or required */
1571
1572         if (vdev->pdev->is_virtfn) {
1573                 struct vfio_pci_core_device *pf_vdev = get_pf_vdev(vdev);
1574                 bool match;
1575
1576                 if (!pf_vdev) {
1577                         if (!vf_token)
1578                                 return 0; /* PF is not vfio-pci, no VF token */
1579
1580                         pci_info_ratelimited(vdev->pdev,
1581                                 "VF token incorrectly provided, PF not bound to vfio-pci\n");
1582                         return -EINVAL;
1583                 }
1584
1585                 if (!vf_token) {
1586                         vfio_device_put(&pf_vdev->vdev);
1587                         pci_info_ratelimited(vdev->pdev,
1588                                 "VF token required to access device\n");
1589                         return -EACCES;
1590                 }
1591
1592                 mutex_lock(&pf_vdev->vf_token->lock);
1593                 match = uuid_equal(uuid, &pf_vdev->vf_token->uuid);
1594                 mutex_unlock(&pf_vdev->vf_token->lock);
1595
1596                 vfio_device_put(&pf_vdev->vdev);
1597
1598                 if (!match) {
1599                         pci_info_ratelimited(vdev->pdev,
1600                                 "Incorrect VF token provided for device\n");
1601                         return -EACCES;
1602                 }
1603         } else if (vdev->vf_token) {
1604                 mutex_lock(&vdev->vf_token->lock);
1605                 if (vdev->vf_token->users) {
1606                         if (!vf_token) {
1607                                 mutex_unlock(&vdev->vf_token->lock);
1608                                 pci_info_ratelimited(vdev->pdev,
1609                                         "VF token required to access device\n");
1610                                 return -EACCES;
1611                         }
1612
1613                         if (!uuid_equal(uuid, &vdev->vf_token->uuid)) {
1614                                 mutex_unlock(&vdev->vf_token->lock);
1615                                 pci_info_ratelimited(vdev->pdev,
1616                                         "Incorrect VF token provided for device\n");
1617                                 return -EACCES;
1618                         }
1619                 } else if (vf_token) {
1620                         uuid_copy(&vdev->vf_token->uuid, uuid);
1621                 }
1622
1623                 mutex_unlock(&vdev->vf_token->lock);
1624         } else if (vf_token) {
1625                 pci_info_ratelimited(vdev->pdev,
1626                         "VF token incorrectly provided, not a PF or VF\n");
1627                 return -EINVAL;
1628         }
1629
1630         return 0;
1631 }
1632
1633 #define VF_TOKEN_ARG "vf_token="
1634
1635 int vfio_pci_core_match(struct vfio_device *core_vdev, char *buf)
1636 {
1637         struct vfio_pci_core_device *vdev =
1638                 container_of(core_vdev, struct vfio_pci_core_device, vdev);
1639         bool vf_token = false;
1640         uuid_t uuid;
1641         int ret;
1642
1643         if (strncmp(pci_name(vdev->pdev), buf, strlen(pci_name(vdev->pdev))))
1644                 return 0; /* No match */
1645
1646         if (strlen(buf) > strlen(pci_name(vdev->pdev))) {
1647                 buf += strlen(pci_name(vdev->pdev));
1648
1649                 if (*buf != ' ')
1650                         return 0; /* No match: non-whitespace after name */
1651
1652                 while (*buf) {
1653                         if (*buf == ' ') {
1654                                 buf++;
1655                                 continue;
1656                         }
1657
1658                         if (!vf_token && !strncmp(buf, VF_TOKEN_ARG,
1659                                                   strlen(VF_TOKEN_ARG))) {
1660                                 buf += strlen(VF_TOKEN_ARG);
1661
1662                                 if (strlen(buf) < UUID_STRING_LEN)
1663                                         return -EINVAL;
1664
1665                                 ret = uuid_parse(buf, &uuid);
1666                                 if (ret)
1667                                         return ret;
1668
1669                                 vf_token = true;
1670                                 buf += UUID_STRING_LEN;
1671                         } else {
1672                                 /* Unknown/duplicate option */
1673                                 return -EINVAL;
1674                         }
1675                 }
1676         }
1677
1678         ret = vfio_pci_validate_vf_token(vdev, vf_token, &uuid);
1679         if (ret)
1680                 return ret;
1681
1682         return 1; /* Match */
1683 }
1684 EXPORT_SYMBOL_GPL(vfio_pci_core_match);
1685
1686 static int vfio_pci_bus_notifier(struct notifier_block *nb,
1687                                  unsigned long action, void *data)
1688 {
1689         struct vfio_pci_core_device *vdev = container_of(nb,
1690                                                     struct vfio_pci_core_device, nb);
1691         struct device *dev = data;
1692         struct pci_dev *pdev = to_pci_dev(dev);
1693         struct pci_dev *physfn = pci_physfn(pdev);
1694
1695         if (action == BUS_NOTIFY_ADD_DEVICE &&
1696             pdev->is_virtfn && physfn == vdev->pdev) {
1697                 pci_info(vdev->pdev, "Captured SR-IOV VF %s driver_override\n",
1698                          pci_name(pdev));
1699                 pdev->driver_override = kasprintf(GFP_KERNEL, "%s",
1700                                                   vdev->vdev.ops->name);
1701         } else if (action == BUS_NOTIFY_BOUND_DRIVER &&
1702                    pdev->is_virtfn && physfn == vdev->pdev) {
1703                 struct pci_driver *drv = pci_dev_driver(pdev);
1704
1705                 if (drv && drv != pci_dev_driver(vdev->pdev))
1706                         pci_warn(vdev->pdev,
1707                                  "VF %s bound to driver %s while PF bound to driver %s\n",
1708                                  pci_name(pdev), drv->name,
1709                                  pci_dev_driver(vdev->pdev)->name);
1710         }
1711
1712         return 0;
1713 }
1714
1715 static int vfio_pci_vf_init(struct vfio_pci_core_device *vdev)
1716 {
1717         struct pci_dev *pdev = vdev->pdev;
1718         int ret;
1719
1720         if (!pdev->is_physfn)
1721                 return 0;
1722
1723         vdev->vf_token = kzalloc(sizeof(*vdev->vf_token), GFP_KERNEL);
1724         if (!vdev->vf_token)
1725                 return -ENOMEM;
1726
1727         mutex_init(&vdev->vf_token->lock);
1728         uuid_gen(&vdev->vf_token->uuid);
1729
1730         vdev->nb.notifier_call = vfio_pci_bus_notifier;
1731         ret = bus_register_notifier(&pci_bus_type, &vdev->nb);
1732         if (ret) {
1733                 kfree(vdev->vf_token);
1734                 return ret;
1735         }
1736         return 0;
1737 }
1738
1739 static void vfio_pci_vf_uninit(struct vfio_pci_core_device *vdev)
1740 {
1741         if (!vdev->vf_token)
1742                 return;
1743
1744         bus_unregister_notifier(&pci_bus_type, &vdev->nb);
1745         WARN_ON(vdev->vf_token->users);
1746         mutex_destroy(&vdev->vf_token->lock);
1747         kfree(vdev->vf_token);
1748 }
1749
1750 static int vfio_pci_vga_init(struct vfio_pci_core_device *vdev)
1751 {
1752         struct pci_dev *pdev = vdev->pdev;
1753         int ret;
1754
1755         if (!vfio_pci_is_vga(pdev))
1756                 return 0;
1757
1758         ret = vga_client_register(pdev, vfio_pci_set_decode);
1759         if (ret)
1760                 return ret;
1761         vga_set_legacy_decoding(pdev, vfio_pci_set_decode(pdev, false));
1762         return 0;
1763 }
1764
1765 static void vfio_pci_vga_uninit(struct vfio_pci_core_device *vdev)
1766 {
1767         struct pci_dev *pdev = vdev->pdev;
1768
1769         if (!vfio_pci_is_vga(pdev))
1770                 return;
1771         vga_client_unregister(pdev);
1772         vga_set_legacy_decoding(pdev, VGA_RSRC_NORMAL_IO | VGA_RSRC_NORMAL_MEM |
1773                                               VGA_RSRC_LEGACY_IO |
1774                                               VGA_RSRC_LEGACY_MEM);
1775 }
1776
1777 void vfio_pci_core_init_device(struct vfio_pci_core_device *vdev,
1778                                struct pci_dev *pdev,
1779                                const struct vfio_device_ops *vfio_pci_ops)
1780 {
1781         vfio_init_group_dev(&vdev->vdev, &pdev->dev, vfio_pci_ops);
1782         vdev->pdev = pdev;
1783         vdev->irq_type = VFIO_PCI_NUM_IRQS;
1784         mutex_init(&vdev->igate);
1785         spin_lock_init(&vdev->irqlock);
1786         mutex_init(&vdev->ioeventfds_lock);
1787         INIT_LIST_HEAD(&vdev->dummy_resources_list);
1788         INIT_LIST_HEAD(&vdev->ioeventfds_list);
1789         mutex_init(&vdev->vma_lock);
1790         INIT_LIST_HEAD(&vdev->vma_list);
1791         init_rwsem(&vdev->memory_lock);
1792 }
1793 EXPORT_SYMBOL_GPL(vfio_pci_core_init_device);
1794
1795 void vfio_pci_core_uninit_device(struct vfio_pci_core_device *vdev)
1796 {
1797         mutex_destroy(&vdev->igate);
1798         mutex_destroy(&vdev->ioeventfds_lock);
1799         mutex_destroy(&vdev->vma_lock);
1800         vfio_uninit_group_dev(&vdev->vdev);
1801         kfree(vdev->region);
1802         kfree(vdev->pm_save);
1803 }
1804 EXPORT_SYMBOL_GPL(vfio_pci_core_uninit_device);
1805
1806 int vfio_pci_core_register_device(struct vfio_pci_core_device *vdev)
1807 {
1808         struct pci_dev *pdev = vdev->pdev;
1809         struct iommu_group *group;
1810         int ret;
1811
1812         if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL)
1813                 return -EINVAL;
1814
1815         /*
1816          * Prevent binding to PFs with VFs enabled, the VFs might be in use
1817          * by the host or other users.  We cannot capture the VFs if they
1818          * already exist, nor can we track VF users.  Disabling SR-IOV here
1819          * would initiate removing the VFs, which would unbind the driver,
1820          * which is prone to blocking if that VF is also in use by vfio-pci.
1821          * Just reject these PFs and let the user sort it out.
1822          */
1823         if (pci_num_vf(pdev)) {
1824                 pci_warn(pdev, "Cannot bind to PF with SR-IOV enabled\n");
1825                 return -EBUSY;
1826         }
1827
1828         group = vfio_iommu_group_get(&pdev->dev);
1829         if (!group)
1830                 return -EINVAL;
1831
1832         if (pci_is_root_bus(pdev->bus)) {
1833                 ret = vfio_assign_device_set(&vdev->vdev, vdev);
1834         } else if (!pci_probe_reset_slot(pdev->slot)) {
1835                 ret = vfio_assign_device_set(&vdev->vdev, pdev->slot);
1836         } else {
1837                 /*
1838                  * If there is no slot reset support for this device, the whole
1839                  * bus needs to be grouped together to support bus-wide resets.
1840                  */
1841                 ret = vfio_assign_device_set(&vdev->vdev, pdev->bus);
1842         }
1843
1844         if (ret)
1845                 goto out_group_put;
1846         ret = vfio_pci_vf_init(vdev);
1847         if (ret)
1848                 goto out_group_put;
1849         ret = vfio_pci_vga_init(vdev);
1850         if (ret)
1851                 goto out_vf;
1852
1853         vfio_pci_probe_power_state(vdev);
1854
1855         if (!disable_idle_d3) {
1856                 /*
1857                  * pci-core sets the device power state to an unknown value at
1858                  * bootup and after being removed from a driver.  The only
1859                  * transition it allows from this unknown state is to D0, which
1860                  * typically happens when a driver calls pci_enable_device().
1861                  * We're not ready to enable the device yet, but we do want to
1862                  * be able to get to D3.  Therefore first do a D0 transition
1863                  * before going to D3.
1864                  */
1865                 vfio_pci_set_power_state(vdev, PCI_D0);
1866                 vfio_pci_set_power_state(vdev, PCI_D3hot);
1867         }
1868
1869         ret = vfio_register_group_dev(&vdev->vdev);
1870         if (ret)
1871                 goto out_power;
1872         return 0;
1873
1874 out_power:
1875         if (!disable_idle_d3)
1876                 vfio_pci_set_power_state(vdev, PCI_D0);
1877 out_vf:
1878         vfio_pci_vf_uninit(vdev);
1879 out_group_put:
1880         vfio_iommu_group_put(group, &pdev->dev);
1881         return ret;
1882 }
1883 EXPORT_SYMBOL_GPL(vfio_pci_core_register_device);
1884
1885 void vfio_pci_core_unregister_device(struct vfio_pci_core_device *vdev)
1886 {
1887         struct pci_dev *pdev = vdev->pdev;
1888
1889         pci_disable_sriov(pdev);
1890
1891         vfio_unregister_group_dev(&vdev->vdev);
1892
1893         vfio_pci_vf_uninit(vdev);
1894         vfio_pci_vga_uninit(vdev);
1895
1896         vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev);
1897
1898         if (!disable_idle_d3)
1899                 vfio_pci_set_power_state(vdev, PCI_D0);
1900 }
1901 EXPORT_SYMBOL_GPL(vfio_pci_core_unregister_device);
1902
1903 static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
1904                                                   pci_channel_state_t state)
1905 {
1906         struct vfio_pci_core_device *vdev;
1907         struct vfio_device *device;
1908
1909         device = vfio_device_get_from_dev(&pdev->dev);
1910         if (device == NULL)
1911                 return PCI_ERS_RESULT_DISCONNECT;
1912
1913         vdev = container_of(device, struct vfio_pci_core_device, vdev);
1914
1915         mutex_lock(&vdev->igate);
1916
1917         if (vdev->err_trigger)
1918                 eventfd_signal(vdev->err_trigger, 1);
1919
1920         mutex_unlock(&vdev->igate);
1921
1922         vfio_device_put(device);
1923
1924         return PCI_ERS_RESULT_CAN_RECOVER;
1925 }
1926
1927 int vfio_pci_core_sriov_configure(struct pci_dev *pdev, int nr_virtfn)
1928 {
1929         struct vfio_device *device;
1930         int ret = 0;
1931
1932         device = vfio_device_get_from_dev(&pdev->dev);
1933         if (!device)
1934                 return -ENODEV;
1935
1936         if (nr_virtfn == 0)
1937                 pci_disable_sriov(pdev);
1938         else
1939                 ret = pci_enable_sriov(pdev, nr_virtfn);
1940
1941         vfio_device_put(device);
1942
1943         return ret < 0 ? ret : nr_virtfn;
1944 }
1945 EXPORT_SYMBOL_GPL(vfio_pci_core_sriov_configure);
1946
1947 const struct pci_error_handlers vfio_pci_core_err_handlers = {
1948         .error_detected = vfio_pci_aer_err_detected,
1949 };
1950 EXPORT_SYMBOL_GPL(vfio_pci_core_err_handlers);
1951
1952 static bool vfio_dev_in_groups(struct vfio_pci_core_device *vdev,
1953                                struct vfio_pci_group_info *groups)
1954 {
1955         unsigned int i;
1956
1957         for (i = 0; i < groups->count; i++)
1958                 if (groups->groups[i] == vdev->vdev.group)
1959                         return true;
1960         return false;
1961 }
1962
1963 static int vfio_pci_is_device_in_set(struct pci_dev *pdev, void *data)
1964 {
1965         struct vfio_device_set *dev_set = data;
1966         struct vfio_device *cur;
1967
1968         list_for_each_entry(cur, &dev_set->device_list, dev_set_list)
1969                 if (cur->dev == &pdev->dev)
1970                         return 0;
1971         return -EBUSY;
1972 }
1973
1974 /*
1975  * vfio-core considers a group to be viable and will create a vfio_device even
1976  * if some devices are bound to drivers like pci-stub or pcieport. Here we
1977  * require all PCI devices to be inside our dev_set since that ensures they stay
1978  * put and that every driver controlling the device can co-ordinate with the
1979  * device reset.
1980  *
1981  * Returns the pci_dev to pass to pci_reset_bus() if every PCI device to be
1982  * reset is inside the dev_set, and pci_reset_bus() can succeed. NULL otherwise.
1983  */
1984 static struct pci_dev *
1985 vfio_pci_dev_set_resettable(struct vfio_device_set *dev_set)
1986 {
1987         struct pci_dev *pdev;
1988
1989         lockdep_assert_held(&dev_set->lock);
1990
1991         /*
1992          * By definition all PCI devices in the dev_set share the same PCI
1993          * reset, so any pci_dev will have the same outcomes for
1994          * pci_probe_reset_*() and pci_reset_bus().
1995          */
1996         pdev = list_first_entry(&dev_set->device_list,
1997                                 struct vfio_pci_core_device,
1998                                 vdev.dev_set_list)->pdev;
1999
2000         /* pci_reset_bus() is supported */
2001         if (pci_probe_reset_slot(pdev->slot) && pci_probe_reset_bus(pdev->bus))
2002                 return NULL;
2003
2004         if (vfio_pci_for_each_slot_or_bus(pdev, vfio_pci_is_device_in_set,
2005                                           dev_set,
2006                                           !pci_probe_reset_slot(pdev->slot)))
2007                 return NULL;
2008         return pdev;
2009 }
2010
2011 /*
2012  * We need to get memory_lock for each device, but devices can share mmap_lock,
2013  * therefore we need to zap and hold the vma_lock for each device, and only then
2014  * get each memory_lock.
2015  */
2016 static int vfio_pci_dev_set_hot_reset(struct vfio_device_set *dev_set,
2017                                       struct vfio_pci_group_info *groups)
2018 {
2019         struct vfio_pci_core_device *cur_mem;
2020         struct vfio_pci_core_device *cur_vma;
2021         struct vfio_pci_core_device *cur;
2022         struct pci_dev *pdev;
2023         bool is_mem = true;
2024         int ret;
2025
2026         mutex_lock(&dev_set->lock);
2027         cur_mem = list_first_entry(&dev_set->device_list,
2028                                    struct vfio_pci_core_device,
2029                                    vdev.dev_set_list);
2030
2031         pdev = vfio_pci_dev_set_resettable(dev_set);
2032         if (!pdev) {
2033                 ret = -EINVAL;
2034                 goto err_unlock;
2035         }
2036
2037         list_for_each_entry(cur_vma, &dev_set->device_list, vdev.dev_set_list) {
2038                 /*
2039                  * Test whether all the affected devices are contained by the
2040                  * set of groups provided by the user.
2041                  */
2042                 if (!vfio_dev_in_groups(cur_vma, groups)) {
2043                         ret = -EINVAL;
2044                         goto err_undo;
2045                 }
2046
2047                 /*
2048                  * Locking multiple devices is prone to deadlock, runaway and
2049                  * unwind if we hit contention.
2050                  */
2051                 if (!vfio_pci_zap_and_vma_lock(cur_vma, true)) {
2052                         ret = -EBUSY;
2053                         goto err_undo;
2054                 }
2055         }
2056         cur_vma = NULL;
2057
2058         list_for_each_entry(cur_mem, &dev_set->device_list, vdev.dev_set_list) {
2059                 if (!down_write_trylock(&cur_mem->memory_lock)) {
2060                         ret = -EBUSY;
2061                         goto err_undo;
2062                 }
2063                 mutex_unlock(&cur_mem->vma_lock);
2064         }
2065         cur_mem = NULL;
2066
2067         ret = pci_reset_bus(pdev);
2068
2069 err_undo:
2070         list_for_each_entry(cur, &dev_set->device_list, vdev.dev_set_list) {
2071                 if (cur == cur_mem)
2072                         is_mem = false;
2073                 if (cur == cur_vma)
2074                         break;
2075                 if (is_mem)
2076                         up_write(&cur->memory_lock);
2077                 else
2078                         mutex_unlock(&cur->vma_lock);
2079         }
2080 err_unlock:
2081         mutex_unlock(&dev_set->lock);
2082         return ret;
2083 }
2084
2085 static bool vfio_pci_dev_set_needs_reset(struct vfio_device_set *dev_set)
2086 {
2087         struct vfio_pci_core_device *cur;
2088         bool needs_reset = false;
2089
2090         list_for_each_entry(cur, &dev_set->device_list, vdev.dev_set_list) {
2091                 /* No VFIO device in the set can have an open device FD */
2092                 if (cur->vdev.open_count)
2093                         return false;
2094                 needs_reset |= cur->needs_reset;
2095         }
2096         return needs_reset;
2097 }
2098
2099 /*
2100  * If a bus or slot reset is available for the provided dev_set and:
2101  *  - All of the devices affected by that bus or slot reset are unused
2102  *  - At least one of the affected devices is marked dirty via
2103  *    needs_reset (such as by lack of FLR support)
2104  * Then attempt to perform that bus or slot reset.
2105  * Returns true if the dev_set was reset.
2106  */
2107 static bool vfio_pci_dev_set_try_reset(struct vfio_device_set *dev_set)
2108 {
2109         struct vfio_pci_core_device *cur;
2110         struct pci_dev *pdev;
2111         int ret;
2112
2113         if (!vfio_pci_dev_set_needs_reset(dev_set))
2114                 return false;
2115
2116         pdev = vfio_pci_dev_set_resettable(dev_set);
2117         if (!pdev)
2118                 return false;
2119
2120         ret = pci_reset_bus(pdev);
2121         if (ret)
2122                 return false;
2123
2124         list_for_each_entry(cur, &dev_set->device_list, vdev.dev_set_list) {
2125                 cur->needs_reset = false;
2126                 if (!disable_idle_d3)
2127                         vfio_pci_set_power_state(cur, PCI_D3hot);
2128         }
2129         return true;
2130 }
2131
2132 void vfio_pci_core_set_params(bool is_nointxmask, bool is_disable_vga,
2133                               bool is_disable_idle_d3)
2134 {
2135         nointxmask = is_nointxmask;
2136         disable_vga = is_disable_vga;
2137         disable_idle_d3 = is_disable_idle_d3;
2138 }
2139 EXPORT_SYMBOL_GPL(vfio_pci_core_set_params);
2140
2141 static void vfio_pci_core_cleanup(void)
2142 {
2143         vfio_pci_uninit_perm_bits();
2144 }
2145
2146 static int __init vfio_pci_core_init(void)
2147 {
2148         /* Allocate shared config space permission data used by all devices */
2149         return vfio_pci_init_perm_bits();
2150 }
2151
2152 module_init(vfio_pci_core_init);
2153 module_exit(vfio_pci_core_cleanup);
2154
2155 MODULE_LICENSE("GPL v2");
2156 MODULE_AUTHOR(DRIVER_AUTHOR);
2157 MODULE_DESCRIPTION(DRIVER_DESC);