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          * Careful, device_lock may already be held.  This is the case if
 143          * a driver unbind is blocked.  Try to get the locks ourselves to
 144          * prevent a deadlock.
 145          */
 146         if (vdev->reset_works) {
 147                 bool reset_done = false;
 148
 149                 if (pci_cfg_access_trylock(pdev)) {
 150                         if (device_trylock(&pdev->dev)) {
 151                                 __pci_reset_function_locked(pdev);
 152                                 reset_done = true;
 153                                 device_unlock(&pdev->dev);
 154                         }
 155                         pci_cfg_access_unlock(pdev);
 156                 }
 157
 158                 if (!reset_done)
 159                         pr_warn("%s: Unable to acquire locks for reset of %s\n",
 160                                 __func__, dev_name(&pdev->dev));
 161         }
 162
 163         pci_restore_state(pdev);
 164 }
 165
 166 static void vfio_pci_release(void *device_data)
 167 {
 168         struct vfio_pci_device *vdev = device_data;
 169
 170         if (atomic_dec_and_test(&vdev->refcnt))
 171                 vfio_pci_disable(vdev);
 172
 173         module_put(THIS_MODULE);
 174 }
 175
 176 static int vfio_pci_open(void *device_data)
 177 {
 178         struct vfio_pci_device *vdev = device_data;
 179
 180         if (!try_module_get(THIS_MODULE))
 181                 return -ENODEV;
 182
 183         if (atomic_inc_return(&vdev->refcnt) == 1) {
 184                 int ret = vfio_pci_enable(vdev);
 185                 if (ret) {
 186                         module_put(THIS_MODULE);
 187                         return ret;
 188                 }
 189         }
 190
 191         return 0;
 192 }
 193
 194 static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type)
 195 {
 196         if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) {
 197                 u8 pin;
 198                 pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN, &pin);
 199                 if (pin)
 200                         return 1;
 201
 202         } else if (irq_type == VFIO_PCI_MSI_IRQ_INDEX) {
 203                 u8 pos;
 204                 u16 flags;
 205
 206                 pos = vdev->pdev->msi_cap;
 207                 if (pos) {
 208                         pci_read_config_word(vdev->pdev,
 209                                              pos + PCI_MSI_FLAGS, &flags);
 210
 211                         return 1 << (flags & PCI_MSI_FLAGS_QMASK);
 212                 }
 213         } else if (irq_type == VFIO_PCI_MSIX_IRQ_INDEX) {
 214                 u8 pos;
 215                 u16 flags;
 216
 217                 pos = vdev->pdev->msix_cap;
 218                 if (pos) {
 219                         pci_read_config_word(vdev->pdev,
 220                                              pos + PCI_MSIX_FLAGS, &flags);
 221
 222                         return (flags & PCI_MSIX_FLAGS_QSIZE) + 1;
 223                 }
 224         } else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX)
 225                 if (pci_is_pcie(vdev->pdev))
 226                         return 1;
 227
 228         return 0;
 229 }
 230
 231 static int vfio_pci_count_devs(struct pci_dev *pdev, void *data)
 232 {
 233         (*(int *)data)++;
 234         return 0;
 235 }
 236
 237 struct vfio_pci_fill_info {
 238         int max;
 239         int cur;
 240         struct vfio_pci_dependent_device *devices;
 241 };
 242
 243 static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data)
 244 {
 245         struct vfio_pci_fill_info *fill = data;
 246         struct iommu_group *iommu_group;
 247
 248         if (fill->cur == fill->max)
 249                 return -EAGAIN; /* Something changed, try again */
 250
 251         iommu_group = iommu_group_get(&pdev->dev);
 252         if (!iommu_group)
 253                 return -EPERM; /* Cannot reset non-isolated devices */
 254
 255         fill->devices[fill->cur].group_id = iommu_group_id(iommu_group);
 256         fill->devices[fill->cur].segment = pci_domain_nr(pdev->bus);
 257         fill->devices[fill->cur].bus = pdev->bus->number;
 258         fill->devices[fill->cur].devfn = pdev->devfn;
 259         fill->cur++;
 260         iommu_group_put(iommu_group);
 261         return 0;
 262 }
 263
 264 struct vfio_pci_group_entry {
 265         struct vfio_group *group;
 266         int id;
 267 };
 268
 269 struct vfio_pci_group_info {
 270         int count;
 271         struct vfio_pci_group_entry *groups;
 272 };
 273
 274 static int vfio_pci_validate_devs(struct pci_dev *pdev, void *data)
 275 {
 276         struct vfio_pci_group_info *info = data;
 277         struct iommu_group *group;
 278         int id, i;
 279
 280         group = iommu_group_get(&pdev->dev);
 281         if (!group)
 282                 return -EPERM;
 283
 284         id = iommu_group_id(group);
 285
 286         for (i = 0; i < info->count; i++)
 287                 if (info->groups[i].id == id)
 288                         break;
 289
 290         iommu_group_put(group);
 291
 292         return (i == info->count) ? -EINVAL : 0;
 293 }
 294
 295 static bool vfio_pci_dev_below_slot(struct pci_dev *pdev, struct pci_slot *slot)
 296 {
 297         for (; pdev; pdev = pdev->bus->self)
 298                 if (pdev->bus == slot->bus)
 299                         return (pdev->slot == slot);
 300         return false;
 301 }
 302
 303 struct vfio_pci_walk_info {
 304         int (*fn)(struct pci_dev *, void *data);
 305         void *data;
 306         struct pci_dev *pdev;
 307         bool slot;
 308         int ret;
 309 };
 310
 311 static int vfio_pci_walk_wrapper(struct pci_dev *pdev, void *data)
 312 {
 313         struct vfio_pci_walk_info *walk = data;
 314
 315         if (!walk->slot || vfio_pci_dev_below_slot(pdev, walk->pdev->slot))
 316                 walk->ret = walk->fn(pdev, walk->data);
 317
 318         return walk->ret;
 319 }
 320
 321 static int vfio_pci_for_each_slot_or_bus(struct pci_dev *pdev,
 322                                          int (*fn)(struct pci_dev *,
 323                                                    void *data), void *data,
 324                                          bool slot)
 325 {
 326         struct vfio_pci_walk_info walk = {
 327                 .fn = fn, .data = data, .pdev = pdev, .slot = slot, .ret = 0,
 328         };
 329
 330         pci_walk_bus(pdev->bus, vfio_pci_walk_wrapper, &walk);
 331
 332         return walk.ret;
 333 }
 334
 335 static long vfio_pci_ioctl(void *device_data,
 336                            unsigned int cmd, unsigned long arg)
 337 {
 338         struct vfio_pci_device *vdev = device_data;
 339         unsigned long minsz;
 340
 341         if (cmd == VFIO_DEVICE_GET_INFO) {
 342                 struct vfio_device_info info;
 343
 344                 minsz = offsetofend(struct vfio_device_info, num_irqs);
 345
 346                 if (copy_from_user(&info, (void __user *)arg, minsz))
 347                         return -EFAULT;
 348
 349                 if (info.argsz < minsz)
 350                         return -EINVAL;
 351
 352                 info.flags = VFIO_DEVICE_FLAGS_PCI;
 353
 354                 if (vdev->reset_works)
 355                         info.flags |= VFIO_DEVICE_FLAGS_RESET;
 356
 357                 info.num_regions = VFIO_PCI_NUM_REGIONS;
 358                 info.num_irqs = VFIO_PCI_NUM_IRQS;
 359
 360                 return copy_to_user((void __user *)arg, &info, minsz);
 361
 362         } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
 363                 struct pci_dev *pdev = vdev->pdev;
 364                 struct vfio_region_info info;
 365
 366                 minsz = offsetofend(struct vfio_region_info, offset);
 367
 368                 if (copy_from_user(&info, (void __user *)arg, minsz))
 369                         return -EFAULT;
 370
 371                 if (info.argsz < minsz)
 372                         return -EINVAL;
 373
 374                 switch (info.index) {
 375                 case VFIO_PCI_CONFIG_REGION_INDEX:
 376                         info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 377                         info.size = pdev->cfg_size;
 378                         info.flags = VFIO_REGION_INFO_FLAG_READ |
 379                                      VFIO_REGION_INFO_FLAG_WRITE;
 380                         break;
 381                 case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
 382                         info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 383                         info.size = pci_resource_len(pdev, info.index);
 384                         if (!info.size) {
 385                                 info.flags = 0;
 386                                 break;
 387                         }
 388
 389                         info.flags = VFIO_REGION_INFO_FLAG_READ |
 390                                      VFIO_REGION_INFO_FLAG_WRITE;
 391                         if (pci_resource_flags(pdev, info.index) &
 392                             IORESOURCE_MEM && info.size >= PAGE_SIZE)
 393                                 info.flags |= VFIO_REGION_INFO_FLAG_MMAP;
 394                         break;
 395                 case VFIO_PCI_ROM_REGION_INDEX:
 396                 {
 397                         void __iomem *io;
 398                         size_t size;
 399
 400                         info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 401                         info.flags = 0;
 402
 403                         /* Report the BAR size, not the ROM size */
 404                         info.size = pci_resource_len(pdev, info.index);
 405                         if (!info.size)
 406                                 break;
 407
 408                         /* Is it really there? */
 409                         io = pci_map_rom(pdev, &size);
 410                         if (!io || !size) {
 411                                 info.size = 0;
 412                                 break;
 413                         }
 414                         pci_unmap_rom(pdev, io);
 415
 416                         info.flags = VFIO_REGION_INFO_FLAG_READ;
 417                         break;
 418                 }
 419                 case VFIO_PCI_VGA_REGION_INDEX:
 420                         if (!vdev->has_vga)
 421                                 return -EINVAL;
 422
 423                         info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
 424                         info.size = 0xc0000;
 425                         info.flags = VFIO_REGION_INFO_FLAG_READ |
 426                                      VFIO_REGION_INFO_FLAG_WRITE;
 427
 428                         break;
 429                 default:
 430                         return -EINVAL;
 431                 }
 432
 433                 return copy_to_user((void __user *)arg, &info, minsz);
 434
 435         } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
 436                 struct vfio_irq_info info;
 437
 438                 minsz = offsetofend(struct vfio_irq_info, count);
 439
 440                 if (copy_from_user(&info, (void __user *)arg, minsz))
 441                         return -EFAULT;
 442
 443                 if (info.argsz < minsz || info.index >= VFIO_PCI_NUM_IRQS)
 444                         return -EINVAL;
 445
 446                 switch (info.index) {
 447                 case VFIO_PCI_INTX_IRQ_INDEX ... VFIO_PCI_MSIX_IRQ_INDEX:
 448                         break;
 449                 case VFIO_PCI_ERR_IRQ_INDEX:
 450                         if (pci_is_pcie(vdev->pdev))
 451                                 break;
 452                 /* pass thru to return error */
 453                 default:
 454                         return -EINVAL;
 455                 }
 456
 457                 info.flags = VFIO_IRQ_INFO_EVENTFD;
 458
 459                 info.count = vfio_pci_get_irq_count(vdev, info.index);
 460
 461                 if (info.index == VFIO_PCI_INTX_IRQ_INDEX)
 462                         info.flags |= (VFIO_IRQ_INFO_MASKABLE |
 463                                        VFIO_IRQ_INFO_AUTOMASKED);
 464                 else
 465                         info.flags |= VFIO_IRQ_INFO_NORESIZE;
 466
 467                 return copy_to_user((void __user *)arg, &info, minsz);
 468
 469         } else if (cmd == VFIO_DEVICE_SET_IRQS) {
 470                 struct vfio_irq_set hdr;
 471                 u8 *data = NULL;
 472                 int ret = 0;
 473
 474                 minsz = offsetofend(struct vfio_irq_set, count);
 475
 476                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 477                         return -EFAULT;
 478
 479                 if (hdr.argsz < minsz || hdr.index >= VFIO_PCI_NUM_IRQS ||
 480                     hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
 481                                   VFIO_IRQ_SET_ACTION_TYPE_MASK))
 482                         return -EINVAL;
 483
 484                 if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
 485                         size_t size;
 486                         int max = vfio_pci_get_irq_count(vdev, hdr.index);
 487
 488                         if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
 489                                 size = sizeof(uint8_t);
 490                         else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD)
 491                                 size = sizeof(int32_t);
 492                         else
 493                                 return -EINVAL;
 494
 495                         if (hdr.argsz - minsz < hdr.count * size ||
 496                             hdr.start >= max || hdr.start + hdr.count > max)
 497                                 return -EINVAL;
 498
 499                         data = memdup_user((void __user *)(arg + minsz),
 500                                            hdr.count * size);
 501                         if (IS_ERR(data))
 502                                 return PTR_ERR(data);
 503                 }
 504
 505                 mutex_lock(&vdev->igate);
 506
 507                 ret = vfio_pci_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
 508                                               hdr.start, hdr.count, data);
 509
 510                 mutex_unlock(&vdev->igate);
 511                 kfree(data);
 512
 513                 return ret;
 514
 515         } else if (cmd == VFIO_DEVICE_RESET) {
 516                 return vdev->reset_works ?
 517                         pci_reset_function(vdev->pdev) : -EINVAL;
 518
 519         } else if (cmd == VFIO_DEVICE_GET_PCI_HOT_RESET_INFO) {
 520                 struct vfio_pci_hot_reset_info hdr;
 521                 struct vfio_pci_fill_info fill = { 0 };
 522                 struct vfio_pci_dependent_device *devices = NULL;
 523                 bool slot = false;
 524                 int ret = 0;
 525
 526                 minsz = offsetofend(struct vfio_pci_hot_reset_info, count);
 527
 528                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 529                         return -EFAULT;
 530
 531                 if (hdr.argsz < minsz)
 532                         return -EINVAL;
 533
 534                 hdr.flags = 0;
 535
 536                 /* Can we do a slot or bus reset or neither? */
 537                 if (!pci_probe_reset_slot(vdev->pdev->slot))
 538                         slot = true;
 539                 else if (pci_probe_reset_bus(vdev->pdev->bus))
 540                         return -ENODEV;
 541
 542                 /* How many devices are affected? */
 543                 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
 544                                                     vfio_pci_count_devs,
 545                                                     &fill.max, slot);
 546                 if (ret)
 547                         return ret;
 548
 549                 WARN_ON(!fill.max); /* Should always be at least one */
 550
 551                 /*
 552                  * If there's enough space, fill it now, otherwise return
 553                  * -ENOSPC and the number of devices affected.
 554                  */
 555                 if (hdr.argsz < sizeof(hdr) + (fill.max * sizeof(*devices))) {
 556                         ret = -ENOSPC;
 557                         hdr.count = fill.max;
 558                         goto reset_info_exit;
 559                 }
 560
 561                 devices = kcalloc(fill.max, sizeof(*devices), GFP_KERNEL);
 562                 if (!devices)
 563                         return -ENOMEM;
 564
 565                 fill.devices = devices;
 566
 567                 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
 568                                                     vfio_pci_fill_devs,
 569                                                     &fill, slot);
 570
 571                 /*
 572                  * If a device was removed between counting and filling,
 573                  * we may come up short of fill.max.  If a device was
 574                  * added, we'll have a return of -EAGAIN above.
 575                  */
 576                 if (!ret)
 577                         hdr.count = fill.cur;
 578
 579 reset_info_exit:
 580                 if (copy_to_user((void __user *)arg, &hdr, minsz))
 581                         ret = -EFAULT;
 582
 583                 if (!ret) {
 584                         if (copy_to_user((void __user *)(arg + minsz), devices,
 585                                          hdr.count * sizeof(*devices)))
 586                                 ret = -EFAULT;
 587                 }
 588
 589                 kfree(devices);
 590                 return ret;
 591
 592         } else if (cmd == VFIO_DEVICE_PCI_HOT_RESET) {
 593                 struct vfio_pci_hot_reset hdr;
 594                 int32_t *group_fds;
 595                 struct vfio_pci_group_entry *groups;
 596                 struct vfio_pci_group_info info;
 597                 bool slot = false;
 598                 int i, count = 0, ret = 0;
 599
 600                 minsz = offsetofend(struct vfio_pci_hot_reset, count);
 601
 602                 if (copy_from_user(&hdr, (void __user *)arg, minsz))
 603                         return -EFAULT;
 604
 605                 if (hdr.argsz < minsz || hdr.flags)
 606                         return -EINVAL;
 607
 608                 /* Can we do a slot or bus reset or neither? */
 609                 if (!pci_probe_reset_slot(vdev->pdev->slot))
 610                         slot = true;
 611                 else if (pci_probe_reset_bus(vdev->pdev->bus))
 612                         return -ENODEV;
 613
 614                 /*
 615                  * We can't let userspace give us an arbitrarily large
 616                  * buffer to copy, so verify how many we think there
 617                  * could be.  Note groups can have multiple devices so
 618                  * one group per device is the max.
 619                  */
 620                 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
 621                                                     vfio_pci_count_devs,
 622                                                     &count, slot);
 623                 if (ret)
 624                         return ret;
 625
 626                 /* Somewhere between 1 and count is OK */
 627                 if (!hdr.count || hdr.count > count)
 628                         return -EINVAL;
 629
 630                 group_fds = kcalloc(hdr.count, sizeof(*group_fds), GFP_KERNEL);
 631                 groups = kcalloc(hdr.count, sizeof(*groups), GFP_KERNEL);
 632                 if (!group_fds || !groups) {
 633                         kfree(group_fds);
 634                         kfree(groups);
 635                         return -ENOMEM;
 636                 }
 637
 638                 if (copy_from_user(group_fds, (void __user *)(arg + minsz),
 639                                    hdr.count * sizeof(*group_fds))) {
 640                         kfree(group_fds);
 641                         kfree(groups);
 642                         return -EFAULT;
 643                 }
 644
 645                 /*
 646                  * For each group_fd, get the group through the vfio external
 647                  * user interface and store the group and iommu ID.  This
 648                  * ensures the group is held across the reset.
 649                  */
 650                 for (i = 0; i < hdr.count; i++) {
 651                         struct vfio_group *group;
 652                         struct fd f = fdget(group_fds[i]);
 653                         if (!f.file) {
 654                                 ret = -EBADF;
 655                                 break;
 656                         }
 657
 658                         group = vfio_group_get_external_user(f.file);
 659                         fdput(f);
 660                         if (IS_ERR(group)) {
 661                                 ret = PTR_ERR(group);
 662                                 break;
 663                         }
 664
 665                         groups[i].group = group;
 666                         groups[i].id = vfio_external_user_iommu_id(group);
 667                 }
 668
 669                 kfree(group_fds);
 670
 671                 /* release reference to groups on error */
 672                 if (ret)
 673                         goto hot_reset_release;
 674
 675                 info.count = hdr.count;
 676                 info.groups = groups;
 677
 678                 /*
 679                  * Test whether all the affected devices are contained
 680                  * by the set of groups provided by the user.
 681                  */
 682                 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
 683                                                     vfio_pci_validate_devs,
 684                                                     &info, slot);
 685                 if (!ret)
 686                         /* User has access, do the reset */
 687                         ret = slot ? pci_reset_slot(vdev->pdev->slot) :
 688                                      pci_reset_bus(vdev->pdev->bus);
 689
 690 hot_reset_release:
 691                 for (i--; i >= 0; i--)
 692                         vfio_group_put_external_user(groups[i].group);
 693
 694                 kfree(groups);
 695                 return ret;
 696         }
 697
 698         return -ENOTTY;
 699 }
 700
 701 static ssize_t vfio_pci_rw(void *device_data, char __user *buf,
 702                            size_t count, loff_t *ppos, bool iswrite)
 703 {
 704         unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
 705         struct vfio_pci_device *vdev = device_data;
 706
 707         if (index >= VFIO_PCI_NUM_REGIONS)
 708                 return -EINVAL;
 709
 710         switch (index) {
 711         case VFIO_PCI_CONFIG_REGION_INDEX:
 712                 return vfio_pci_config_rw(vdev, buf, count, ppos, iswrite);
 713
 714         case VFIO_PCI_ROM_REGION_INDEX:
 715                 if (iswrite)
 716                         return -EINVAL;
 717                 return vfio_pci_bar_rw(vdev, buf, count, ppos, false);
 718
 719         case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
 720                 return vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite);
 721
 722         case VFIO_PCI_VGA_REGION_INDEX:
 723                 return vfio_pci_vga_rw(vdev, buf, count, ppos, iswrite);
 724         }
 725
 726         return -EINVAL;
 727 }
 728
 729 static ssize_t vfio_pci_read(void *device_data, char __user *buf,
 730                              size_t count, loff_t *ppos)
 731 {
 732         if (!count)
 733                 return 0;
 734
 735         return vfio_pci_rw(device_data, buf, count, ppos, false);
 736 }
 737
 738 static ssize_t vfio_pci_write(void *device_data, const char __user *buf,
 739                               size_t count, loff_t *ppos)
 740 {
 741         if (!count)
 742                 return 0;
 743
 744         return vfio_pci_rw(device_data, (char __user *)buf, count, ppos, true);
 745 }
 746
 747 static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma)
 748 {
 749         struct vfio_pci_device *vdev = device_data;
 750         struct pci_dev *pdev = vdev->pdev;
 751         unsigned int index;
 752         u64 phys_len, req_len, pgoff, req_start;
 753         int ret;
 754
 755         index = vma->vm_pgoff >> (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT);
 756
 757         if (vma->vm_end < vma->vm_start)
 758                 return -EINVAL;
 759         if ((vma->vm_flags & VM_SHARED) == 0)
 760                 return -EINVAL;
 761         if (index >= VFIO_PCI_ROM_REGION_INDEX)
 762                 return -EINVAL;
 763         if (!(pci_resource_flags(pdev, index) & IORESOURCE_MEM))
 764                 return -EINVAL;
 765
 766         phys_len = pci_resource_len(pdev, index);
 767         req_len = vma->vm_end - vma->vm_start;
 768         pgoff = vma->vm_pgoff &
 769                 ((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
 770         req_start = pgoff << PAGE_SHIFT;
 771
 772         if (phys_len < PAGE_SIZE || req_start + req_len > phys_len)
 773                 return -EINVAL;
 774
 775         if (index == vdev->msix_bar) {
 776                 /*
 777                  * Disallow mmaps overlapping the MSI-X table; users don't
 778                  * get to touch this directly.  We could find somewhere
 779                  * else to map the overlap, but page granularity is only
 780                  * a recommendation, not a requirement, so the user needs
 781                  * to know which bits are real.  Requiring them to mmap
 782                  * around the table makes that clear.
 783                  */
 784
 785                 /* If neither entirely above nor below, then it overlaps */
 786                 if (!(req_start >= vdev->msix_offset + vdev->msix_size ||
 787                       req_start + req_len <= vdev->msix_offset))
 788                         return -EINVAL;
 789         }
 790
 791         /*
 792          * Even though we don't make use of the barmap for the mmap,
 793          * we need to request the region and the barmap tracks that.
 794          */
 795         if (!vdev->barmap[index]) {
 796                 ret = pci_request_selected_regions(pdev,
 797                                                    1 << index, "vfio-pci");
 798                 if (ret)
 799                         return ret;
 800
 801                 vdev->barmap[index] = pci_iomap(pdev, index, 0);
 802         }
 803
 804         vma->vm_private_data = vdev;
 805         vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
 806         vma->vm_pgoff = (pci_resource_start(pdev, index) >> PAGE_SHIFT) + pgoff;
 807
 808         return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
 809                                req_len, vma->vm_page_prot);
 810 }
 811
 812 static const struct vfio_device_ops vfio_pci_ops = {
 813         .name           = "vfio-pci",
 814         .open           = vfio_pci_open,
 815         .release        = vfio_pci_release,
 816         .ioctl          = vfio_pci_ioctl,
 817         .read           = vfio_pci_read,
 818         .write          = vfio_pci_write,
 819         .mmap           = vfio_pci_mmap,
 820 };
 821
 822 static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 823 {
 824         u8 type;
 825         struct vfio_pci_device *vdev;
 826         struct iommu_group *group;
 827         int ret;
 828
 829         pci_read_config_byte(pdev, PCI_HEADER_TYPE, &type);
 830         if ((type & PCI_HEADER_TYPE) != PCI_HEADER_TYPE_NORMAL)
 831                 return -EINVAL;
 832
 833         group = iommu_group_get(&pdev->dev);
 834         if (!group)
 835                 return -EINVAL;
 836
 837         vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
 838         if (!vdev) {
 839                 iommu_group_put(group);
 840                 return -ENOMEM;
 841         }
 842
 843         vdev->pdev = pdev;
 844         vdev->irq_type = VFIO_PCI_NUM_IRQS;
 845         mutex_init(&vdev->igate);
 846         spin_lock_init(&vdev->irqlock);
 847         atomic_set(&vdev->refcnt, 0);
 848
 849         ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev);
 850         if (ret) {
 851                 iommu_group_put(group);
 852                 kfree(vdev);
 853         }
 854
 855         return ret;
 856 }
 857
 858 static void vfio_pci_remove(struct pci_dev *pdev)
 859 {
 860         struct vfio_pci_device *vdev;
 861
 862         vdev = vfio_del_group_dev(&pdev->dev);
 863         if (!vdev)
 864                 return;
 865
 866         iommu_group_put(pdev->dev.iommu_group);
 867         kfree(vdev);
 868 }
 869
 870 static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
 871                                                   pci_channel_state_t state)
 872 {
 873         struct vfio_pci_device *vdev;
 874         struct vfio_device *device;
 875
 876         device = vfio_device_get_from_dev(&pdev->dev);
 877         if (device == NULL)
 878                 return PCI_ERS_RESULT_DISCONNECT;
 879
 880         vdev = vfio_device_data(device);
 881         if (vdev == NULL) {
 882                 vfio_device_put(device);
 883                 return PCI_ERS_RESULT_DISCONNECT;
 884         }
 885
 886         if (vdev->err_trigger)
 887                 eventfd_signal(vdev->err_trigger, 1);
 888
 889         vfio_device_put(device);
 890
 891         return PCI_ERS_RESULT_CAN_RECOVER;
 892 }
 893
 894 static struct pci_error_handlers vfio_err_handlers = {
 895         .error_detected = vfio_pci_aer_err_detected,
 896 };
 897
 898 static struct pci_driver vfio_pci_driver = {
 899         .name           = "vfio-pci",
 900         .id_table       = NULL, /* only dynamic ids */
 901         .probe          = vfio_pci_probe,
 902         .remove         = vfio_pci_remove,
 903         .err_handler    = &vfio_err_handlers,
 904 };
 905
 906 static void __exit vfio_pci_cleanup(void)
 907 {
 908         pci_unregister_driver(&vfio_pci_driver);
 909         vfio_pci_virqfd_exit();
 910         vfio_pci_uninit_perm_bits();
 911 }
 912
 913 static int __init vfio_pci_init(void)
 914 {
 915         int ret;
 916
 917         /* Allocate shared config space permision data used by all devices */
 918         ret = vfio_pci_init_perm_bits();
 919         if (ret)
 920                 return ret;
 921
 922         /* Start the virqfd cleanup handler */
 923         ret = vfio_pci_virqfd_init();
 924         if (ret)
 925                 goto out_virqfd;
 926
 927         /* Register and scan for devices */
 928         ret = pci_register_driver(&vfio_pci_driver);
 929         if (ret)
 930                 goto out_driver;
 931
 932         return 0;
 933
 934 out_driver:
 935         vfio_pci_virqfd_exit();
 936 out_virqfd:
 937         vfio_pci_uninit_perm_bits();
 938         return ret;
 939 }
 940
 941 module_init(vfio_pci_init);
 942 module_exit(vfio_pci_cleanup);
 943
 944 MODULE_VERSION(DRIVER_VERSION);
 945 MODULE_LICENSE("GPL v2");
 946 MODULE_AUTHOR(DRIVER_AUTHOR);
 947 MODULE_DESCRIPTION(DRIVER_DESC);