drivers/vfio/pci/vfio_pci.c

   1 /*
   2  * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
   3  *     Author: Alex Williamson <alex.williamson@redhat.com>
   4  *
   5  * This program is free software; you can redistribute it and/or modify
   6  * it under the terms of the GNU General Public License version 2 as
   7  * published by the Free Software Foundation.
   8  *
   9  * Derived from original vfio:
  10  * Copyright 2010 Cisco Systems, Inc.  All rights reserved.
  11  * Author: Tom Lyon, pugs@cisco.com
  12  */
  13
  14 #include <linux/device.h>
  15 #include <linux/eventfd.h>
  16 #include <linux/file.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/iommu.h>
  19 #include <linux/module.h>
  20 #include <linux/mutex.h>
  21 #include <linux/notifier.h>
  22 #include <linux/pci.h>
  23 #include <linux/pm_runtime.h>
  24 #include <linux/slab.h>
  25 #include <linux/types.h>
  26 #include <linux/uaccess.h>
  27 #include <linux/vfio.h>
  28
  29 #include "vfio_pci_private.h"
  30
  31 #define DRIVER_VERSION  "0.2"
  32 #define DRIVER_AUTHOR   "Alex Williamson <alex.williamson@redhat.com>"
  33 #define DRIVER_DESC     "VFIO PCI - User Level meta-driver"
  34
  35 static bool nointxmask;
  36 module_param_named(nointxmask, nointxmask, bool, S_IRUGO | S_IWUSR);
  37 MODULE_PARM_DESC(nointxmask,
  38                   "Disable support for PCI 2.3 style INTx masking.  If this resolves problems for specific devices, report lspci -vvvxxx to linux-pci@vger.kernel.org so the device can be fixed automatically via the broken_intx_masking flag.");
  39
  40 static int vfio_pci_enable(struct vfio_pci_device *vdev)
  41 {
  42         struct pci_dev *pdev = vdev->pdev;
  43         int ret;
  44         u16 cmd;
  45         u8 msix_pos;
  46
  47         ret = pci_enable_device(pdev);
  48         if (ret)
  49                 return ret;
  50
  51         vdev->reset_works = (pci_reset_function(pdev) == 0);
  52         pci_save_state(pdev);
  53         vdev->pci_saved_state = pci_store_saved_state(pdev);
  54         if (!vdev->pci_saved_state)
  55                 pr_debug("%s: Couldn't store %s saved state\n",
  56                          __func__, dev_name(&pdev->dev));
  57
  58         ret = vfio_config_init(vdev);
  59         if (ret) {
  60                 pci_load_and_free_saved_state(pdev, &vdev->pci_saved_state);
  61                 pci_disable_device(pdev);
  62                 return ret;
  63         }
  64
  65         if (likely(!nointxmask))
  66                 vdev->pci_2_3 = pci_intx_mask_supported(pdev);
  67
  68         pci_read_config_word(pdev, PCI_COMMAND, &cmd);
  69         if (vdev->pci_2_3 && (cmd & PCI_COMMAND_INTX_DISABLE)) {
  70                 cmd &= ~PCI_COMMAND_INTX_DISABLE;
  71                 pci_write_config_word(pdev, PCI_COMMAND, cmd);
  72         }
  73
  74         msix_pos = pdev->msix_cap;
  75         if (msix_pos) {
  76                 u16 flags;
  77                 u32 table;
  78
  79                 pci_read_config_word(pdev, msix_pos + PCI_MSIX_FLAGS, &flags);
  80                 pci_read_config_dword(pdev, msix_pos + PCI_MSIX_TABLE, &table);
  81
  82                 vdev->msix_bar = table & PCI_MSIX_TABLE_BIR;
  83                 vdev->msix_offset = table & PCI_MSIX_TABLE_OFFSET;
  84                 vdev->msix_size = ((flags & PCI_MSIX_FLAGS_QSIZE) + 1) * 16;
  85         } else
  86                 vdev->msix_bar = 0xFF;
  87
  88 #ifdef CONFIG_VFIO_PCI_VGA
  89         if ((pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA)
  90                 vdev->has_vga = true;
  91 #endif
  92
  93         return 0;
  94 }
  95
  96 static void vfio_pci_disable(struct vfio_pci_device *vdev)
  97 {
  98         struct pci_dev *pdev = vdev->pdev;
  99         int bar;
 100
 101         pci_disable_device(pdev);
 102
 103         vfio_pci_set_irqs_ioctl(vdev, VFIO_IRQ_SET_DATA_NONE |
 104                                 VFIO_IRQ_SET_ACTION_TRIGGER,
 105                                 vdev->irq_type, 0, 0, NULL);
 106
 107         vdev->virq_disabled = false;
 108
 109         vfio_config_free(vdev);
 110
 111         for (bar = PCI_STD_RESOURCES; bar <= PCI_STD_RESOURCE_END; bar++) {
 112                 if (!vdev->barmap[bar])
 113                         continue;
 114                 pci_iounmap(pdev, vdev->barmap[bar]);
 115                 pci_release_selected_regions(pdev, 1 << bar);
 116                 vdev->barmap[bar] = NULL;
 117         }
 118
 119         /*
 120          * If we have saved state, restore it.  If we can reset the device,
 121          * even better.  Resetting with current state seems better than
 122          * nothing, but saving and restoring current state without reset
 123          * is just busy work.
 124          */
 125         if (pci_load_and_free_saved_state(pdev, &vdev->pci_saved_state)) {
 126                 pr_info("%s: Couldn't reload %s saved state\n",
 127                         __func__, dev_name(&pdev->dev));
 128
 129                 if (!vdev->reset_works)
 130                         return;
 131
 132                 pci_save_state(pdev);
 133         }
 134
 135         /*
 136          * Disable INTx and MSI, presumably to avoid spurious interrupts
 137          * during reset.  Stolen from pci_reset_function()
 138          */
 139         pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
 140
 141         /*
 142          * Try to reset the device.  The success of this is dependent on
 143          * being able to lock the device, which is not always possible.
 144          */
 145         if (vdev->reset_works) {
 146                 int ret = pci_try_reset_function(pdev);
 147                 if (ret)
 148                         pr_warn("%s: Failed to reset device %s (%d)\n",
 149                                 __func__, dev_name(&pdev->dev), ret);
 150         }
 151
 152         pci_restore_state(pdev);
 153 }
 154
 155 static void vfio_pci_release(void *device_data)
 156 {
 157         struct vfio_pci_device *vdev = device_data;
 158
 159         if (atomic_dec_and_test(&vdev->refcnt))
 160                 vfio_pci_disable(vdev);
 161
 162         module_put(THIS_MODULE);
 163 }
 164
 165 static int vfio_pci_open(void *device_data)
 166 {
 167         struct vfio_pci_device *vdev = device_data;
 168
 169         if (!try_module_get(THIS_MODULE))
 170                 return -ENODEV;
 171
 172         if (atomic_inc_return(&vdev->refcnt) == 1) {
 173                 int ret = vfio_pci_enable(vdev);
 174                 if (ret) {
 175                         module_put(THIS_MODULE);
 176                         return ret;
 177                 }
 178         }
 179
 180         return 0;
 181 }
 182
 183 static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type)
 184 {
 185         if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) {
 186                 u8 pin;
 187                 pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN, &pin);
 188                 if (pin)
 189                         return 1;
 190
 191         } else if (irq_type == VFIO_PCI_MSI_IRQ_INDEX) {
 192                 u8 pos;
 193                 u16 flags;
 194
 195                 pos = vdev->pdev->msi_cap;
 196                 if (pos) {
 197                         pci_read_config_word(vdev->pdev,
 198                                              pos + PCI_MSI_FLAGS, &flags);
 199
 200                         return 1 << (flags & PCI_MSI_FLAGS_QMASK);
 201                 }
 202         } else if (irq_type == VFIO_PCI_MSIX_IRQ_INDEX) {
 203                 u8 pos;
 204                 u16 flags;
 205
 206                 pos = vdev->pdev->msix_cap;
 207                 if (pos) {
 208                         pci_read_config_word(vdev->pdev,
 209                                              pos + PCI_MSIX_FLAGS, &flags);
 210
 211                         return (flags & PCI_MSIX_FLAGS_QSIZE) + 1;
 212                 }
 213         } else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX)
 214                 if (pci_is_pcie(vdev->pdev))
 215                         return 1;
 216
 217         return 0;
 218 }
 219
 220 static int vfio_pci_count_devs(struct pci_dev *pdev, void *data)
 221 {
 222         (*(int *)data)++;
 223         return 0;
 224 }
 225
 226 struct vfio_pci_fill_info {
 227         int max;
 228         int cur;
 229         struct vfio_pci_dependent_device *devices;
 230 };
 231
 232 static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data)
 233 {
 234         struct vfio_pci_fill_info *fill = data;
 235         struct iommu_group *iommu_group;
 236
 237         if (fill->cur == fill->max)
 238                 return -EAGAIN; /* Something changed, try again */
 239
 240         iommu_group = iommu_group_get(&pdev->dev);
 241         if (!iommu_group)
 242                 return -EPERM; /* Cannot reset non-isolated devices */
 243
 244         fill->devices[fill->cur].group_id = iommu_group_id(iommu_group);
 245         fill->devices[fill->cur].segment = pci_domain_nr(pdev->bus);
 246         fill->devices[fill->cur].bus = pdev->bus->number;
 247         fill->devices[fill->cur].devfn = pdev->devfn;
 248         fill->cur++;
 249         iommu_group_put(iommu_group);
 250         return 0;
 251 }
 252
 253 struct vfio_pci_group_entry {
 254         struct vfio_group *group;
 255         int id;
 256 };
 257
 258 struct vfio_pci_group_info {
 259         int count;
 260         struct vfio_pci_group_entry *groups;
 261 };
 262
 263 static int vfio_pci_validate_devs(struct pci_dev *pdev, void *data)
 264 {
 265         struct vfio_pci_group_info *info = data;
 266         struct iommu_group *group;
 267         int id, i;
 268
 269         group = iommu_group_get(&pdev->dev);
 270         if (!group)
 271                 return -EPERM;
 272
 273         id = iommu_group_id(group);
 274
 275         for (i = 0; i < info->count; i++)
 276                 if (info->groups[i].id == id)
 277                         break;
 278
 279         iommu_group_put(group);
 280
 281         return (i == info->count) ? -EINVAL : 0;
 282 }
 283
 284 static bool vfio_pci_dev_below_slot(struct pci_dev *pdev, struct pci_slot *slot)
 285 {
 286         for (; pdev; pdev = pdev->bus->self)
 287                 if (pdev->bus == slot->bus)
 288                         return (pdev->slot == slot);
 289         return false;
 290 }
 291
 292 struct vfio_pci_walk_info {
 293         int (*fn)(struct pci_dev *, void *data);
 294         void *data;
 295         struct pci_dev *pdev;
 296         bool slot;
 297         int ret;
 298 };
 299
 300 static int vfio_pci_walk_wrapper(struct pci_dev *pdev, void *data)
 301 {
 302         struct vfio_pci_walk_info *walk = data;
 303
 304         if (!walk->slot || vfio_pci_dev_below_slot(pdev, walk->pdev->slot))
 305                 walk->ret = walk->fn(pdev, walk->data);
 306
 307         return walk->ret;
 308 }
 309
 310 static int vfio_pci_for_each_slot_or_bus(struct pci_dev *pdev,
 311                                          int (*fn)(struct pci_dev *,
 312                                                    void *data), void *data,
 313                                          bool slot)
 314 {
 315         struct vfio_pci_walk_info walk = {
 316                 .fn = fn, .data = data, .pdev = pdev, .slot = slot, .ret = 0,
 317         };
 318
 319         pci_walk_bus(pdev->bus, vfio_pci_walk_wrapper, &walk);
 320
 321         return walk.ret;
 322 }
 323
 324 static long vfio_pci_ioctl(void *device_data,
 325                            unsigned int cmd, unsigned long arg)
 326 {
 327         struct vfio_pci_device *vdev = device_data;
 328         unsigned long minsz;
 329
 330         if (cmd == VFIO_DEVICE_GET_INFO) {
 331                 struct vfio_device_info info;
 332
 333                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 334
 335                 if (copy_from_user(&info, (void __user *)arg, minsz))
 336                         return -EFAULT;
 337
 338                 if (info.argsz < minsz)
 339                         return -EINVAL;
 340
 341                 info.flags = VFIO_DEVICE_FLAGS_PCI;
 342
 343                 if (vdev->reset_works)
 344                         info.flags |= VFIO_DEVICE_FLAGS_RESET;
 345
 346                 info.num_regions = VFIO_PCI_NUM_REGIONS;
 347                 info.num_irqs = VFIO_PCI_NUM_IRQS;
 348
 349                 return copy_to_user((void __user *)arg, &info, minsz);
 350
 351         } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
 352                 struct pci_dev *pdev = vdev->pdev;
 353                 struct vfio_region_info info;
 354
 355                 minsz = offsetofend(struct vfio_region_info, offset);
 356
 357                 if (copy_from_user(&info, (void __user *)arg, minsz))
 358                         return -EFAULT;
 359
 360                 if (info.argsz < minsz)
 361                         return -EINVAL;
 362
 363                 switch (info.index) {
 364                 case VFIO_PCI_CONFIG_REGION_INDEX:
 365                         info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 366                         info.size = pdev->cfg_size;
 367                         info.flags = VFIO_REGION_INFO_FLAG_READ |
 368                                      VFIO_REGION_INFO_FLAG_WRITE;
 369                         break;
 370                 case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
 371                         info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 372                         info.size = pci_resource_len(pdev, info.index);
 373                         if (!info.size) {
 374                                 info.flags = 0;
 375                                 break;
 376                         }
 377
 378                         info.flags = VFIO_REGION_INFO_FLAG_READ |
 379                                      VFIO_REGION_INFO_FLAG_WRITE;
 380                         if (pci_resource_flags(pdev, info.index) &
 381                             IORESOURCE_MEM && info.size >= PAGE_SIZE)
 382                                 info.flags |= VFIO_REGION_INFO_FLAG_MMAP;
 383                         break;
 384                 case VFIO_PCI_ROM_REGION_INDEX:
 385                 {
 386                         void __iomem *io;
 387                         size_t size;
 388
 389                         info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 390                         info.flags = 0;
 391
 392                         /* Report the BAR size, not the ROM size */
 393                         info.size = pci_resource_len(pdev, info.index);
 394                         if (!info.size)
 395                                 break;
 396
 397                         /* Is it really there? */
 398                         io = pci_map_rom(pdev, &size);
 399                         if (!io || !size) {
 400                                 info.size = 0;
 401                                 break;
 402                         }
 403                         pci_unmap_rom(pdev, io);
 404
 405                         info.flags = VFIO_REGION_INFO_FLAG_READ;
 406                         break;
 407                 }
 408                 case VFIO_PCI_VGA_REGION_INDEX:
 409                         if (!vdev->has_vga)
 410                                 return -EINVAL;
 411
 412                         info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 413                         info.size = 0xc0000;
 414                         info.flags = VFIO_REGION_INFO_FLAG_READ |
 415                                      VFIO_REGION_INFO_FLAG_WRITE;
 416
 417                         break;
 418                 default:
 419                         return -EINVAL;
 420                 }
 421
 422                 return copy_to_user((void __user *)arg, &info, minsz);
 423
 424         } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
 425                 struct vfio_irq_info info;
 426
 427                 minsz = offsetofend(struct vfio_irq_info, count);
 428
 429                 if (copy_from_user(&info, (void __user *)arg, minsz))
 430                         return -EFAULT;
 431
 432                 if (info.argsz < minsz || info.index >= VFIO_PCI_NUM_IRQS)
 433                         return -EINVAL;
 434
 435                 switch (info.index) {
 436                 case VFIO_PCI_INTX_IRQ_INDEX ... VFIO_PCI_MSIX_IRQ_INDEX:
 437                         break;
 438                 case VFIO_PCI_ERR_IRQ_INDEX:
 439                         if (pci_is_pcie(vdev->pdev))
 440                                 break;
 441                 /* pass thru to return error */
 442                 default:
 443                         return -EINVAL;
 444                 }
 445
 446                 info.flags = VFIO_IRQ_INFO_EVENTFD;
 447
 448                 info.count = vfio_pci_get_irq_count(vdev, info.index);
 449
 450                 if (info.index == VFIO_PCI_INTX_IRQ_INDEX)
 451                         info.flags |= (VFIO_IRQ_INFO_MASKABLE |
 452                                        VFIO_IRQ_INFO_AUTOMASKED);
 453                 else
 454                         info.flags |= VFIO_IRQ_INFO_NORESIZE;
 455
 456                 return copy_to_user((void __user *)arg, &info, minsz);
 457
 458         } else if (cmd == VFIO_DEVICE_SET_IRQS) {
 459                 struct vfio_irq_set hdr;
 460                 u8 *data = NULL;
 461                 int ret = 0;
 462
 463                 minsz = offsetofend(struct vfio_irq_set, count);
 464
 465                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 466                         return -EFAULT;
 467
 468                 if (hdr.argsz < minsz || hdr.index >= VFIO_PCI_NUM_IRQS ||
 469                     hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
 470                                   VFIO_IRQ_SET_ACTION_TYPE_MASK))
 471                         return -EINVAL;
 472
 473                 if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
 474                         size_t size;
 475                         int max = vfio_pci_get_irq_count(vdev, hdr.index);
 476
 477                         if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
 478                                 size = sizeof(uint8_t);
 479                         else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD)
 480                                 size = sizeof(int32_t);
 481                         else
 482                                 return -EINVAL;
 483
 484                         if (hdr.argsz - minsz < hdr.count * size ||
 485                             hdr.start >= max || hdr.start + hdr.count > max)
 486                                 return -EINVAL;
 487
 488                         data = memdup_user((void __user *)(arg + minsz),
 489                                            hdr.count * size);
 490                         if (IS_ERR(data))
 491                                 return PTR_ERR(data);
 492                 }
 493
 494                 mutex_lock(&vdev->igate);
 495
 496                 ret = vfio_pci_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
 497                                               hdr.start, hdr.count, data);
 498
 499                 mutex_unlock(&vdev->igate);
 500                 kfree(data);
 501
 502                 return ret;
 503
 504         } else if (cmd == VFIO_DEVICE_RESET) {
 505                 return vdev->reset_works ?
 506                         pci_try_reset_function(vdev->pdev) : -EINVAL;
 507
 508         } else if (cmd == VFIO_DEVICE_GET_PCI_HOT_RESET_INFO) {
 509                 struct vfio_pci_hot_reset_info hdr;
 510                 struct vfio_pci_fill_info fill = { 0 };
 511                 struct vfio_pci_dependent_device *devices = NULL;
 512                 bool slot = false;
 513                 int ret = 0;
 514
 515                 minsz = offsetofend(struct vfio_pci_hot_reset_info, count);
 516
 517                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 518                         return -EFAULT;
 519
 520                 if (hdr.argsz < minsz)
 521                         return -EINVAL;
 522
 523                 hdr.flags = 0;
 524
 525                 /* Can we do a slot or bus reset or neither? */
 526                 if (!pci_probe_reset_slot(vdev->pdev->slot))
 527                         slot = true;
 528                 else if (pci_probe_reset_bus(vdev->pdev->bus))
 529                         return -ENODEV;
 530
 531                 /* How many devices are affected? */
 532                 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
 533                                                     vfio_pci_count_devs,
 534                                                     &fill.max, slot);
 535                 if (ret)
 536                         return ret;
 537
 538                 WARN_ON(!fill.max); /* Should always be at least one */
 539
 540                 /*
 541                  * If there's enough space, fill it now, otherwise return
 542                  * -ENOSPC and the number of devices affected.
 543                  */
 544                 if (hdr.argsz < sizeof(hdr) + (fill.max * sizeof(*devices))) {
 545                         ret = -ENOSPC;
 546                         hdr.count = fill.max;
 547                         goto reset_info_exit;
 548                 }
 549
 550                 devices = kcalloc(fill.max, sizeof(*devices), GFP_KERNEL);
 551                 if (!devices)
 552                         return -ENOMEM;
 553
 554                 fill.devices = devices;
 555
 556                 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
 557                                                     vfio_pci_fill_devs,
 558                                                     &fill, slot);
 559
 560                 /*
 561                  * If a device was removed between counting and filling,
 562                  * we may come up short of fill.max.  If a device was
 563                  * added, we'll have a return of -EAGAIN above.
 564                  */
 565                 if (!ret)
 566                         hdr.count = fill.cur;
 567
 568 reset_info_exit:
 569                 if (copy_to_user((void __user *)arg, &hdr, minsz))
 570                         ret = -EFAULT;
 571
 572                 if (!ret) {
 573                         if (copy_to_user((void __user *)(arg + minsz), devices,
 574                                          hdr.count * sizeof(*devices)))
 575                                 ret = -EFAULT;
 576                 }
 577
 578                 kfree(devices);
 579                 return ret;
 580
 581         } else if (cmd == VFIO_DEVICE_PCI_HOT_RESET) {
 582                 struct vfio_pci_hot_reset hdr;
 583                 int32_t *group_fds;
 584                 struct vfio_pci_group_entry *groups;
 585                 struct vfio_pci_group_info info;
 586                 bool slot = false;
 587                 int i, count = 0, ret = 0;
 588
 589                 minsz = offsetofend(struct vfio_pci_hot_reset, count);
 590
 591                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 592                         return -EFAULT;
 593
 594                 if (hdr.argsz < minsz || hdr.flags)
 595                         return -EINVAL;
 596
 597                 /* Can we do a slot or bus reset or neither? */
 598                 if (!pci_probe_reset_slot(vdev->pdev->slot))
 599                         slot = true;
 600                 else if (pci_probe_reset_bus(vdev->pdev->bus))
 601                         return -ENODEV;
 602
 603                 /*
 604                  * We can't let userspace give us an arbitrarily large
 605                  * buffer to copy, so verify how many we think there
 606                  * could be.  Note groups can have multiple devices so
 607                  * one group per device is the max.
 608                  */
 609                 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
 610                                                     vfio_pci_count_devs,
 611                                                     &count, slot);
 612                 if (ret)
 613                         return ret;
 614
 615                 /* Somewhere between 1 and count is OK */
 616                 if (!hdr.count || hdr.count > count)
 617                         return -EINVAL;
 618
 619                 group_fds = kcalloc(hdr.count, sizeof(*group_fds), GFP_KERNEL);
 620                 groups = kcalloc(hdr.count, sizeof(*groups), GFP_KERNEL);
 621                 if (!group_fds || !groups) {
 622                         kfree(group_fds);
 623                         kfree(groups);
 624                         return -ENOMEM;
 625                 }
 626
 627                 if (copy_from_user(group_fds, (void __user *)(arg + minsz),
 628                                    hdr.count * sizeof(*group_fds))) {
 629                         kfree(group_fds);
 630                         kfree(groups);
 631                         return -EFAULT;
 632                 }
 633
 634                 /*
 635                  * For each group_fd, get the group through the vfio external
 636                  * user interface and store the group and iommu ID.  This
 637                  * ensures the group is held across the reset.
 638                  */
 639                 for (i = 0; i < hdr.count; i++) {
 640                         struct vfio_group *group;
 641                         struct fd f = fdget(group_fds[i]);
 642                         if (!f.file) {
 643                                 ret = -EBADF;
 644                                 break;
 645                         }
 646
 647                         group = vfio_group_get_external_user(f.file);
 648                         fdput(f);
 649                         if (IS_ERR(group)) {
 650                                 ret = PTR_ERR(group);
 651                                 break;
 652                         }
 653
 654                         groups[i].group = group;
 655                         groups[i].id = vfio_external_user_iommu_id(group);
 656                 }
 657
 658                 kfree(group_fds);
 659
 660                 /* release reference to groups on error */
 661                 if (ret)
 662                         goto hot_reset_release;
 663
 664                 info.count = hdr.count;
 665                 info.groups = groups;
 666
 667                 /*
 668                  * Test whether all the affected devices are contained
 669                  * by the set of groups provided by the user.
 670                  */
 671                 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
 672                                                     vfio_pci_validate_devs,
 673                                                     &info, slot);
 674                 if (!ret)
 675                         /* User has access, do the reset */
 676                         ret = slot ? pci_try_reset_slot(vdev->pdev->slot) :
 677                                      pci_try_reset_bus(vdev->pdev->bus);
 678
 679 hot_reset_release:
 680                 for (i--; i >= 0; i--)
 681                         vfio_group_put_external_user(groups[i].group);
 682
 683                 kfree(groups);
 684                 return ret;
 685         }
 686
 687         return -ENOTTY;
 688 }
 689
 690 static ssize_t vfio_pci_rw(void *device_data, char __user *buf,
 691                            size_t count, loff_t *ppos, bool iswrite)
 692 {
 693         unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
 694         struct vfio_pci_device *vdev = device_data;
 695
 696         if (index >= VFIO_PCI_NUM_REGIONS)
 697                 return -EINVAL;
 698
 699         switch (index) {
 700         case VFIO_PCI_CONFIG_REGION_INDEX:
 701                 return vfio_pci_config_rw(vdev, buf, count, ppos, iswrite);
 702
 703         case VFIO_PCI_ROM_REGION_INDEX:
 704                 if (iswrite)
 705                         return -EINVAL;
 706                 return vfio_pci_bar_rw(vdev, buf, count, ppos, false);
 707
 708         case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
 709                 return vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite);
 710
 711         case VFIO_PCI_VGA_REGION_INDEX:
 712                 return vfio_pci_vga_rw(vdev, buf, count, ppos, iswrite);
 713         }
 714
 715         return -EINVAL;
 716 }
 717
 718 static ssize_t vfio_pci_read(void *device_data, char __user *buf,
 719                              size_t count, loff_t *ppos)
 720 {
 721         if (!count)
 722                 return 0;
 723
 724         return vfio_pci_rw(device_data, buf, count, ppos, false);
 725 }
 726
 727 static ssize_t vfio_pci_write(void *device_data, const char __user *buf,
 728                               size_t count, loff_t *ppos)
 729 {
 730         if (!count)
 731                 return 0;
 732
 733         return vfio_pci_rw(device_data, (char __user *)buf, count, ppos, true);
 734 }
 735
 736 static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma)
 737 {
 738         struct vfio_pci_device *vdev = device_data;
 739         struct pci_dev *pdev = vdev->pdev;
 740         unsigned int index;
 741         u64 phys_len, req_len, pgoff, req_start;
 742         int ret;
 743
 744         index = vma->vm_pgoff >> (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT);
 745
 746         if (vma->vm_end < vma->vm_start)
 747                 return -EINVAL;
 748         if ((vma->vm_flags & VM_SHARED) == 0)
 749                 return -EINVAL;
 750         if (index >= VFIO_PCI_ROM_REGION_INDEX)
 751                 return -EINVAL;
 752         if (!(pci_resource_flags(pdev, index) & IORESOURCE_MEM))
 753                 return -EINVAL;
 754
 755         phys_len = pci_resource_len(pdev, index);
 756         req_len = vma->vm_end - vma->vm_start;
 757         pgoff = vma->vm_pgoff &
 758                 ((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
 759         req_start = pgoff << PAGE_SHIFT;
 760
 761         if (phys_len < PAGE_SIZE || req_start + req_len > phys_len)
 762                 return -EINVAL;
 763
 764         if (index == vdev->msix_bar) {
 765                 /*
 766                  * Disallow mmaps overlapping the MSI-X table; users don't
 767                  * get to touch this directly.  We could find somewhere
 768                  * else to map the overlap, but page granularity is only
 769                  * a recommendation, not a requirement, so the user needs
 770                  * to know which bits are real.  Requiring them to mmap
 771                  * around the table makes that clear.
 772                  */
 773
 774                 /* If neither entirely above nor below, then it overlaps */
 775                 if (!(req_start >= vdev->msix_offset + vdev->msix_size ||
 776                       req_start + req_len <= vdev->msix_offset))
 777                         return -EINVAL;
 778         }
 779
 780         /*
 781          * Even though we don't make use of the barmap for the mmap,
 782          * we need to request the region and the barmap tracks that.
 783          */
 784         if (!vdev->barmap[index]) {
 785                 ret = pci_request_selected_regions(pdev,
 786                                                    1 << index, "vfio-pci");
 787                 if (ret)
 788                         return ret;
 789
 790                 vdev->barmap[index] = pci_iomap(pdev, index, 0);
 791         }
 792
 793         vma->vm_private_data = vdev;
 794         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 795         vma->vm_pgoff = (pci_resource_start(pdev, index) >> PAGE_SHIFT) + pgoff;
 796
 797         return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
 798                                req_len, vma->vm_page_prot);
 799 }
 800
 801 static const struct vfio_device_ops vfio_pci_ops = {
 802         .name           = "vfio-pci",
 803         .open           = vfio_pci_open,
 804         .release        = vfio_pci_release,
 805         .ioctl          = vfio_pci_ioctl,
 806         .read           = vfio_pci_read,
 807         .write          = vfio_pci_write,
 808         .mmap           = vfio_pci_mmap,
 809 };
 810
 811 static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 812 {
 813         u8 type;
 814         struct vfio_pci_device *vdev;
 815         struct iommu_group *group;
 816         int ret;
 817
 818         pci_read_config_byte(pdev, PCI_HEADER_TYPE, &type);
 819         if ((type & PCI_HEADER_TYPE) != PCI_HEADER_TYPE_NORMAL)
 820                 return -EINVAL;
 821
 822         group = iommu_group_get(&pdev->dev);
 823         if (!group)
 824                 return -EINVAL;
 825
 826         vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
 827         if (!vdev) {
 828                 iommu_group_put(group);
 829                 return -ENOMEM;
 830         }
 831
 832         vdev->pdev = pdev;
 833         vdev->irq_type = VFIO_PCI_NUM_IRQS;
 834         mutex_init(&vdev->igate);
 835         spin_lock_init(&vdev->irqlock);
 836         atomic_set(&vdev->refcnt, 0);
 837
 838         ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev);
 839         if (ret) {
 840                 iommu_group_put(group);
 841                 kfree(vdev);
 842         }
 843
 844         return ret;
 845 }
 846
 847 static void vfio_pci_remove(struct pci_dev *pdev)
 848 {
 849         struct vfio_pci_device *vdev;
 850
 851         vdev = vfio_del_group_dev(&pdev->dev);
 852         if (!vdev)
 853                 return;
 854
 855         iommu_group_put(pdev->dev.iommu_group);
 856         kfree(vdev);
 857 }
 858
 859 static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
 860                                                   pci_channel_state_t state)
 861 {
 862         struct vfio_pci_device *vdev;
 863         struct vfio_device *device;
 864
 865         device = vfio_device_get_from_dev(&pdev->dev);
 866         if (device == NULL)
 867                 return PCI_ERS_RESULT_DISCONNECT;
 868
 869         vdev = vfio_device_data(device);
 870         if (vdev == NULL) {
 871                 vfio_device_put(device);
 872                 return PCI_ERS_RESULT_DISCONNECT;
 873         }
 874
 875         mutex_lock(&vdev->igate);
 876
 877         if (vdev->err_trigger)
 878                 eventfd_signal(vdev->err_trigger, 1);
 879
 880         mutex_unlock(&vdev->igate);
 881
 882         vfio_device_put(device);
 883
 884         return PCI_ERS_RESULT_CAN_RECOVER;
 885 }
 886
 887 static struct pci_error_handlers vfio_err_handlers = {
 888         .error_detected = vfio_pci_aer_err_detected,
 889 };
 890
 891 static struct pci_driver vfio_pci_driver = {
 892         .name           = "vfio-pci",
 893         .id_table       = NULL, /* only dynamic ids */
 894         .probe          = vfio_pci_probe,
 895         .remove         = vfio_pci_remove,
 896         .err_handler    = &vfio_err_handlers,
 897 };
 898
 899 static void __exit vfio_pci_cleanup(void)
 900 {
 901         pci_unregister_driver(&vfio_pci_driver);
 902         vfio_pci_virqfd_exit();
 903         vfio_pci_uninit_perm_bits();
 904 }
 905
 906 static int __init vfio_pci_init(void)
 907 {
 908         int ret;
 909
 910         /* Allocate shared config space permision data used by all devices */
 911         ret = vfio_pci_init_perm_bits();
 912         if (ret)
 913                 return ret;
 914
 915         /* Start the virqfd cleanup handler */
 916         ret = vfio_pci_virqfd_init();
 917         if (ret)
 918                 goto out_virqfd;
 919
 920         /* Register and scan for devices */
 921         ret = pci_register_driver(&vfio_pci_driver);
 922         if (ret)
 923                 goto out_driver;
 924
 925         return 0;
 926
 927 out_driver:
 928         vfio_pci_virqfd_exit();
 929 out_virqfd:
 930         vfio_pci_uninit_perm_bits();
 931         return ret;
 932 }
 933
 934 module_init(vfio_pci_init);
 935 module_exit(vfio_pci_cleanup);
 936
 937 MODULE_VERSION(DRIVER_VERSION);
 938 MODULE_LICENSE("GPL v2");
 939 MODULE_AUTHOR(DRIVER_AUTHOR);
 940 MODULE_DESCRIPTION(DRIVER_DESC);