virt/kvm/assigned-dev.c

   1 /*
   2  * Kernel-based Virtual Machine - device assignment support
   3  *
   4  * Copyright (C) 2010 Red Hat, Inc. and/or its affiliates.
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2.  See
   7  * the COPYING file in the top-level directory.
   8  *
   9  */
  10
  11 #include <linux/kvm_host.h>
  12 #include <linux/kvm.h>
  13 #include <linux/uaccess.h>
  14 #include <linux/vmalloc.h>
  15 #include <linux/errno.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/pci.h>
  18 #include <linux/interrupt.h>
  19 #include <linux/slab.h>
  20 #include <linux/namei.h>
  21 #include <linux/fs.h>
  22 #include "irq.h"
  23
  24 static struct kvm_assigned_dev_kernel *kvm_find_assigned_dev(struct list_head *head,
  25                                                       int assigned_dev_id)
  26 {
  27         struct list_head *ptr;
  28         struct kvm_assigned_dev_kernel *match;
  29
  30         list_for_each(ptr, head) {
  31                 match = list_entry(ptr, struct kvm_assigned_dev_kernel, list);
  32                 if (match->assigned_dev_id == assigned_dev_id)
  33                         return match;
  34         }
  35         return NULL;
  36 }
  37
  38 static int find_index_from_host_irq(struct kvm_assigned_dev_kernel
  39                                     *assigned_dev, int irq)
  40 {
  41         int i, index;
  42         struct msix_entry *host_msix_entries;
  43
  44         host_msix_entries = assigned_dev->host_msix_entries;
  45
  46         index = -1;
  47         for (i = 0; i < assigned_dev->entries_nr; i++)
  48                 if (irq == host_msix_entries[i].vector) {
  49                         index = i;
  50                         break;
  51                 }
  52         if (index < 0)
  53                 printk(KERN_WARNING "Fail to find correlated MSI-X entry!\n");
  54
  55         return index;
  56 }
  57
  58 static irqreturn_t kvm_assigned_dev_intx(int irq, void *dev_id)
  59 {
  60         struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
  61         int ret;
  62
  63         spin_lock(&assigned_dev->intx_lock);
  64         if (pci_check_and_mask_intx(assigned_dev->dev)) {
  65                 assigned_dev->host_irq_disabled = true;
  66                 ret = IRQ_WAKE_THREAD;
  67         } else
  68                 ret = IRQ_NONE;
  69         spin_unlock(&assigned_dev->intx_lock);
  70
  71         return ret;
  72 }
  73
  74 static void
  75 kvm_assigned_dev_raise_guest_irq(struct kvm_assigned_dev_kernel *assigned_dev,
  76                                  int vector)
  77 {
  78         if (unlikely(assigned_dev->irq_requested_type &
  79                      KVM_DEV_IRQ_GUEST_INTX)) {
  80                 spin_lock(&assigned_dev->intx_mask_lock);
  81                 if (!(assigned_dev->flags & KVM_DEV_ASSIGN_MASK_INTX))
  82                         kvm_set_irq(assigned_dev->kvm,
  83                                     assigned_dev->irq_source_id, vector, 1,
  84                                     false);
  85                 spin_unlock(&assigned_dev->intx_mask_lock);
  86         } else
  87                 kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id,
  88                             vector, 1, false);
  89 }
  90
  91 static irqreturn_t kvm_assigned_dev_thread_intx(int irq, void *dev_id)
  92 {
  93         struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
  94
  95         if (!(assigned_dev->flags & KVM_DEV_ASSIGN_PCI_2_3)) {
  96                 spin_lock_irq(&assigned_dev->intx_lock);
  97                 disable_irq_nosync(irq);
  98                 assigned_dev->host_irq_disabled = true;
  99                 spin_unlock_irq(&assigned_dev->intx_lock);
 100         }
 101
 102         kvm_assigned_dev_raise_guest_irq(assigned_dev,
 103                                          assigned_dev->guest_irq);
 104
 105         return IRQ_HANDLED;
 106 }
 107
 108 #ifdef __KVM_HAVE_MSI
 109 static irqreturn_t kvm_assigned_dev_msi(int irq, void *dev_id)
 110 {
 111         struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
 112         int ret = kvm_set_irq_inatomic(assigned_dev->kvm,
 113                                        assigned_dev->irq_source_id,
 114                                        assigned_dev->guest_irq, 1);
 115         return unlikely(ret == -EWOULDBLOCK) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
 116 }
 117
 118 static irqreturn_t kvm_assigned_dev_thread_msi(int irq, void *dev_id)
 119 {
 120         struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
 121
 122         kvm_assigned_dev_raise_guest_irq(assigned_dev,
 123                                          assigned_dev->guest_irq);
 124
 125         return IRQ_HANDLED;
 126 }
 127 #endif
 128
 129 #ifdef __KVM_HAVE_MSIX
 130 static irqreturn_t kvm_assigned_dev_msix(int irq, void *dev_id)
 131 {
 132         struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
 133         int index = find_index_from_host_irq(assigned_dev, irq);
 134         u32 vector;
 135         int ret = 0;
 136
 137         if (index >= 0) {
 138                 vector = assigned_dev->guest_msix_entries[index].vector;
 139                 ret = kvm_set_irq_inatomic(assigned_dev->kvm,
 140                                            assigned_dev->irq_source_id,
 141                                            vector, 1);
 142         }
 143
 144         return unlikely(ret == -EWOULDBLOCK) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
 145 }
 146
 147 static irqreturn_t kvm_assigned_dev_thread_msix(int irq, void *dev_id)
 148 {
 149         struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
 150         int index = find_index_from_host_irq(assigned_dev, irq);
 151         u32 vector;
 152
 153         if (index >= 0) {
 154                 vector = assigned_dev->guest_msix_entries[index].vector;
 155                 kvm_assigned_dev_raise_guest_irq(assigned_dev, vector);
 156         }
 157
 158         return IRQ_HANDLED;
 159 }
 160 #endif
 161
 162 /* Ack the irq line for an assigned device */
 163 static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
 164 {
 165         struct kvm_assigned_dev_kernel *dev =
 166                 container_of(kian, struct kvm_assigned_dev_kernel,
 167                              ack_notifier);
 168
 169         kvm_set_irq(dev->kvm, dev->irq_source_id, dev->guest_irq, 0, false);
 170
 171         spin_lock(&dev->intx_mask_lock);
 172
 173         if (!(dev->flags & KVM_DEV_ASSIGN_MASK_INTX)) {
 174                 bool reassert = false;
 175
 176                 spin_lock_irq(&dev->intx_lock);
 177                 /*
 178                  * The guest IRQ may be shared so this ack can come from an
 179                  * IRQ for another guest device.
 180                  */
 181                 if (dev->host_irq_disabled) {
 182                         if (!(dev->flags & KVM_DEV_ASSIGN_PCI_2_3))
 183                                 enable_irq(dev->host_irq);
 184                         else if (!pci_check_and_unmask_intx(dev->dev))
 185                                 reassert = true;
 186                         dev->host_irq_disabled = reassert;
 187                 }
 188                 spin_unlock_irq(&dev->intx_lock);
 189
 190                 if (reassert)
 191                         kvm_set_irq(dev->kvm, dev->irq_source_id,
 192                                     dev->guest_irq, 1, false);
 193         }
 194
 195         spin_unlock(&dev->intx_mask_lock);
 196 }
 197
 198 static void deassign_guest_irq(struct kvm *kvm,
 199                                struct kvm_assigned_dev_kernel *assigned_dev)
 200 {
 201         if (assigned_dev->ack_notifier.gsi != -1)
 202                 kvm_unregister_irq_ack_notifier(kvm,
 203                                                 &assigned_dev->ack_notifier);
 204
 205         kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id,
 206                     assigned_dev->guest_irq, 0, false);
 207
 208         if (assigned_dev->irq_source_id != -1)
 209                 kvm_free_irq_source_id(kvm, assigned_dev->irq_source_id);
 210         assigned_dev->irq_source_id = -1;
 211         assigned_dev->irq_requested_type &= ~(KVM_DEV_IRQ_GUEST_MASK);
 212 }
 213
 214 /* The function implicit hold kvm->lock mutex due to cancel_work_sync() */
 215 static void deassign_host_irq(struct kvm *kvm,
 216                               struct kvm_assigned_dev_kernel *assigned_dev)
 217 {
 218         /*
 219          * We disable irq here to prevent further events.
 220          *
 221          * Notice this maybe result in nested disable if the interrupt type is
 222          * INTx, but it's OK for we are going to free it.
 223          *
 224          * If this function is a part of VM destroy, please ensure that till
 225          * now, the kvm state is still legal for probably we also have to wait
 226          * on a currently running IRQ handler.
 227          */
 228         if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) {
 229                 int i;
 230                 for (i = 0; i < assigned_dev->entries_nr; i++)
 231                         disable_irq(assigned_dev->host_msix_entries[i].vector);
 232
 233                 for (i = 0; i < assigned_dev->entries_nr; i++)
 234                         free_irq(assigned_dev->host_msix_entries[i].vector,
 235                                  assigned_dev);
 236
 237                 assigned_dev->entries_nr = 0;
 238                 kfree(assigned_dev->host_msix_entries);
 239                 kfree(assigned_dev->guest_msix_entries);
 240                 pci_disable_msix(assigned_dev->dev);
 241         } else {
 242                 /* Deal with MSI and INTx */
 243                 if ((assigned_dev->irq_requested_type &
 244                      KVM_DEV_IRQ_HOST_INTX) &&
 245                     (assigned_dev->flags & KVM_DEV_ASSIGN_PCI_2_3)) {
 246                         spin_lock_irq(&assigned_dev->intx_lock);
 247                         pci_intx(assigned_dev->dev, false);
 248                         spin_unlock_irq(&assigned_dev->intx_lock);
 249                         synchronize_irq(assigned_dev->host_irq);
 250                 } else
 251                         disable_irq(assigned_dev->host_irq);
 252
 253                 free_irq(assigned_dev->host_irq, assigned_dev);
 254
 255                 if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSI)
 256                         pci_disable_msi(assigned_dev->dev);
 257         }
 258
 259         assigned_dev->irq_requested_type &= ~(KVM_DEV_IRQ_HOST_MASK);
 260 }
 261
 262 static int kvm_deassign_irq(struct kvm *kvm,
 263                             struct kvm_assigned_dev_kernel *assigned_dev,
 264                             unsigned long irq_requested_type)
 265 {
 266         unsigned long guest_irq_type, host_irq_type;
 267
 268         if (!irqchip_in_kernel(kvm))
 269                 return -EINVAL;
 270         /* no irq assignment to deassign */
 271         if (!assigned_dev->irq_requested_type)
 272                 return -ENXIO;
 273
 274         host_irq_type = irq_requested_type & KVM_DEV_IRQ_HOST_MASK;
 275         guest_irq_type = irq_requested_type & KVM_DEV_IRQ_GUEST_MASK;
 276
 277         if (host_irq_type)
 278                 deassign_host_irq(kvm, assigned_dev);
 279         if (guest_irq_type)
 280                 deassign_guest_irq(kvm, assigned_dev);
 281
 282         return 0;
 283 }
 284
 285 static void kvm_free_assigned_irq(struct kvm *kvm,
 286                                   struct kvm_assigned_dev_kernel *assigned_dev)
 287 {
 288         kvm_deassign_irq(kvm, assigned_dev, assigned_dev->irq_requested_type);
 289 }
 290
 291 static void kvm_free_assigned_device(struct kvm *kvm,
 292                                      struct kvm_assigned_dev_kernel
 293                                      *assigned_dev)
 294 {
 295         kvm_free_assigned_irq(kvm, assigned_dev);
 296
 297         pci_reset_function(assigned_dev->dev);
 298         if (pci_load_and_free_saved_state(assigned_dev->dev,
 299                                           &assigned_dev->pci_saved_state))
 300                 printk(KERN_INFO "%s: Couldn't reload %s saved state\n",
 301                        __func__, dev_name(&assigned_dev->dev->dev));
 302         else
 303                 pci_restore_state(assigned_dev->dev);
 304
 305         pci_clear_dev_assigned(assigned_dev->dev);
 306
 307         pci_release_regions(assigned_dev->dev);
 308         pci_disable_device(assigned_dev->dev);
 309         pci_dev_put(assigned_dev->dev);
 310
 311         list_del(&assigned_dev->list);
 312         kfree(assigned_dev);
 313 }
 314
 315 void kvm_free_all_assigned_devices(struct kvm *kvm)
 316 {
 317         struct list_head *ptr, *ptr2;
 318         struct kvm_assigned_dev_kernel *assigned_dev;
 319
 320         list_for_each_safe(ptr, ptr2, &kvm->arch.assigned_dev_head) {
 321                 assigned_dev = list_entry(ptr,
 322                                           struct kvm_assigned_dev_kernel,
 323                                           list);
 324
 325                 kvm_free_assigned_device(kvm, assigned_dev);
 326         }
 327 }
 328
 329 static int assigned_device_enable_host_intx(struct kvm *kvm,
 330                                             struct kvm_assigned_dev_kernel *dev)
 331 {
 332         irq_handler_t irq_handler;
 333         unsigned long flags;
 334
 335         dev->host_irq = dev->dev->irq;
 336
 337         /*
 338          * We can only share the IRQ line with other host devices if we are
 339          * able to disable the IRQ source at device-level - independently of
 340          * the guest driver. Otherwise host devices may suffer from unbounded
 341          * IRQ latencies when the guest keeps the line asserted.
 342          */
 343         if (dev->flags & KVM_DEV_ASSIGN_PCI_2_3) {
 344                 irq_handler = kvm_assigned_dev_intx;
 345                 flags = IRQF_SHARED;
 346         } else {
 347                 irq_handler = NULL;
 348                 flags = IRQF_ONESHOT;
 349         }
 350         if (request_threaded_irq(dev->host_irq, irq_handler,
 351                                  kvm_assigned_dev_thread_intx, flags,
 352                                  dev->irq_name, dev))
 353                 return -EIO;
 354
 355         if (dev->flags & KVM_DEV_ASSIGN_PCI_2_3) {
 356                 spin_lock_irq(&dev->intx_lock);
 357                 pci_intx(dev->dev, true);
 358                 spin_unlock_irq(&dev->intx_lock);
 359         }
 360         return 0;
 361 }
 362
 363 #ifdef __KVM_HAVE_MSI
 364 static int assigned_device_enable_host_msi(struct kvm *kvm,
 365                                            struct kvm_assigned_dev_kernel *dev)
 366 {
 367         int r;
 368
 369         if (!dev->dev->msi_enabled) {
 370                 r = pci_enable_msi(dev->dev);
 371                 if (r)
 372                         return r;
 373         }
 374
 375         dev->host_irq = dev->dev->irq;
 376         if (request_threaded_irq(dev->host_irq, kvm_assigned_dev_msi,
 377                                  kvm_assigned_dev_thread_msi, 0,
 378                                  dev->irq_name, dev)) {
 379                 pci_disable_msi(dev->dev);
 380                 return -EIO;
 381         }
 382
 383         return 0;
 384 }
 385 #endif
 386
 387 #ifdef __KVM_HAVE_MSIX
 388 static int assigned_device_enable_host_msix(struct kvm *kvm,
 389                                             struct kvm_assigned_dev_kernel *dev)
 390 {
 391         int i, r = -EINVAL;
 392
 393         /* host_msix_entries and guest_msix_entries should have been
 394          * initialized */
 395         if (dev->entries_nr == 0)
 396                 return r;
 397
 398         r = pci_enable_msix_exact(dev->dev,
 399                                   dev->host_msix_entries, dev->entries_nr);
 400         if (r)
 401                 return r;
 402
 403         for (i = 0; i < dev->entries_nr; i++) {
 404                 r = request_threaded_irq(dev->host_msix_entries[i].vector,
 405                                          kvm_assigned_dev_msix,
 406                                          kvm_assigned_dev_thread_msix,
 407                                          0, dev->irq_name, dev);
 408                 if (r)
 409                         goto err;
 410         }
 411
 412         return 0;
 413 err:
 414         for (i -= 1; i >= 0; i--)
 415                 free_irq(dev->host_msix_entries[i].vector, dev);
 416         pci_disable_msix(dev->dev);
 417         return r;
 418 }
 419
 420 #endif
 421
 422 static int assigned_device_enable_guest_intx(struct kvm *kvm,
 423                                 struct kvm_assigned_dev_kernel *dev,
 424                                 struct kvm_assigned_irq *irq)
 425 {
 426         dev->guest_irq = irq->guest_irq;
 427         dev->ack_notifier.gsi = irq->guest_irq;
 428         return 0;
 429 }
 430
 431 #ifdef __KVM_HAVE_MSI
 432 static int assigned_device_enable_guest_msi(struct kvm *kvm,
 433                         struct kvm_assigned_dev_kernel *dev,
 434                         struct kvm_assigned_irq *irq)
 435 {
 436         dev->guest_irq = irq->guest_irq;
 437         dev->ack_notifier.gsi = -1;
 438         return 0;
 439 }
 440 #endif
 441
 442 #ifdef __KVM_HAVE_MSIX
 443 static int assigned_device_enable_guest_msix(struct kvm *kvm,
 444                         struct kvm_assigned_dev_kernel *dev,
 445                         struct kvm_assigned_irq *irq)
 446 {
 447         dev->guest_irq = irq->guest_irq;
 448         dev->ack_notifier.gsi = -1;
 449         return 0;
 450 }
 451 #endif
 452
 453 static int assign_host_irq(struct kvm *kvm,
 454                            struct kvm_assigned_dev_kernel *dev,
 455                            __u32 host_irq_type)
 456 {
 457         int r = -EEXIST;
 458
 459         if (dev->irq_requested_type & KVM_DEV_IRQ_HOST_MASK)
 460                 return r;
 461
 462         snprintf(dev->irq_name, sizeof(dev->irq_name), "kvm:%s",
 463                  pci_name(dev->dev));
 464
 465         switch (host_irq_type) {
 466         case KVM_DEV_IRQ_HOST_INTX:
 467                 r = assigned_device_enable_host_intx(kvm, dev);
 468                 break;
 469 #ifdef __KVM_HAVE_MSI
 470         case KVM_DEV_IRQ_HOST_MSI:
 471                 r = assigned_device_enable_host_msi(kvm, dev);
 472                 break;
 473 #endif
 474 #ifdef __KVM_HAVE_MSIX
 475         case KVM_DEV_IRQ_HOST_MSIX:
 476                 r = assigned_device_enable_host_msix(kvm, dev);
 477                 break;
 478 #endif
 479         default:
 480                 r = -EINVAL;
 481         }
 482         dev->host_irq_disabled = false;
 483
 484         if (!r)
 485                 dev->irq_requested_type |= host_irq_type;
 486
 487         return r;
 488 }
 489
 490 static int assign_guest_irq(struct kvm *kvm,
 491                             struct kvm_assigned_dev_kernel *dev,
 492                             struct kvm_assigned_irq *irq,
 493                             unsigned long guest_irq_type)
 494 {
 495         int id;
 496         int r = -EEXIST;
 497
 498         if (dev->irq_requested_type & KVM_DEV_IRQ_GUEST_MASK)
 499                 return r;
 500
 501         id = kvm_request_irq_source_id(kvm);
 502         if (id < 0)
 503                 return id;
 504
 505         dev->irq_source_id = id;
 506
 507         switch (guest_irq_type) {
 508         case KVM_DEV_IRQ_GUEST_INTX:
 509                 r = assigned_device_enable_guest_intx(kvm, dev, irq);
 510                 break;
 511 #ifdef __KVM_HAVE_MSI
 512         case KVM_DEV_IRQ_GUEST_MSI:
 513                 r = assigned_device_enable_guest_msi(kvm, dev, irq);
 514                 break;
 515 #endif
 516 #ifdef __KVM_HAVE_MSIX
 517         case KVM_DEV_IRQ_GUEST_MSIX:
 518                 r = assigned_device_enable_guest_msix(kvm, dev, irq);
 519                 break;
 520 #endif
 521         default:
 522                 r = -EINVAL;
 523         }
 524
 525         if (!r) {
 526                 dev->irq_requested_type |= guest_irq_type;
 527                 if (dev->ack_notifier.gsi != -1)
 528                         kvm_register_irq_ack_notifier(kvm, &dev->ack_notifier);
 529         } else {
 530                 kvm_free_irq_source_id(kvm, dev->irq_source_id);
 531                 dev->irq_source_id = -1;
 532         }
 533
 534         return r;
 535 }
 536
 537 /* TODO Deal with KVM_DEV_IRQ_ASSIGNED_MASK_MSIX */
 538 static int kvm_vm_ioctl_assign_irq(struct kvm *kvm,
 539                                    struct kvm_assigned_irq *assigned_irq)
 540 {
 541         int r = -EINVAL;
 542         struct kvm_assigned_dev_kernel *match;
 543         unsigned long host_irq_type, guest_irq_type;
 544
 545         if (!irqchip_in_kernel(kvm))
 546                 return r;
 547
 548         mutex_lock(&kvm->lock);
 549         r = -ENODEV;
 550         match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
 551                                       assigned_irq->assigned_dev_id);
 552         if (!match)
 553                 goto out;
 554
 555         host_irq_type = (assigned_irq->flags & KVM_DEV_IRQ_HOST_MASK);
 556         guest_irq_type = (assigned_irq->flags & KVM_DEV_IRQ_GUEST_MASK);
 557
 558         r = -EINVAL;
 559         /* can only assign one type at a time */
 560         if (hweight_long(host_irq_type) > 1)
 561                 goto out;
 562         if (hweight_long(guest_irq_type) > 1)
 563                 goto out;
 564         if (host_irq_type == 0 && guest_irq_type == 0)
 565                 goto out;
 566
 567         r = 0;
 568         if (host_irq_type)
 569                 r = assign_host_irq(kvm, match, host_irq_type);
 570         if (r)
 571                 goto out;
 572
 573         if (guest_irq_type)
 574                 r = assign_guest_irq(kvm, match, assigned_irq, guest_irq_type);
 575 out:
 576         mutex_unlock(&kvm->lock);
 577         return r;
 578 }
 579
 580 static int kvm_vm_ioctl_deassign_dev_irq(struct kvm *kvm,
 581                                          struct kvm_assigned_irq
 582                                          *assigned_irq)
 583 {
 584         int r = -ENODEV;
 585         struct kvm_assigned_dev_kernel *match;
 586         unsigned long irq_type;
 587
 588         mutex_lock(&kvm->lock);
 589
 590         match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
 591                                       assigned_irq->assigned_dev_id);
 592         if (!match)
 593                 goto out;
 594
 595         irq_type = assigned_irq->flags & (KVM_DEV_IRQ_HOST_MASK |
 596                                           KVM_DEV_IRQ_GUEST_MASK);
 597         r = kvm_deassign_irq(kvm, match, irq_type);
 598 out:
 599         mutex_unlock(&kvm->lock);
 600         return r;
 601 }
 602
 603 /*
 604  * We want to test whether the caller has been granted permissions to
 605  * use this device.  To be able to configure and control the device,
 606  * the user needs access to PCI configuration space and BAR resources.
 607  * These are accessed through PCI sysfs.  PCI config space is often
 608  * passed to the process calling this ioctl via file descriptor, so we
 609  * can't rely on access to that file.  We can check for permissions
 610  * on each of the BAR resource files, which is a pretty clear
 611  * indicator that the user has been granted access to the device.
 612  */
 613 static int probe_sysfs_permissions(struct pci_dev *dev)
 614 {
 615 #ifdef CONFIG_SYSFS
 616         int i;
 617         bool bar_found = false;
 618
 619         for (i = PCI_STD_RESOURCES; i <= PCI_STD_RESOURCE_END; i++) {
 620                 char *kpath, *syspath;
 621                 struct path path;
 622                 struct inode *inode;
 623                 int r;
 624
 625                 if (!pci_resource_len(dev, i))
 626                         continue;
 627
 628                 kpath = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
 629                 if (!kpath)
 630                         return -ENOMEM;
 631
 632                 /* Per sysfs-rules, sysfs is always at /sys */
 633                 syspath = kasprintf(GFP_KERNEL, "/sys%s/resource%d", kpath, i);
 634                 kfree(kpath);
 635                 if (!syspath)
 636                         return -ENOMEM;
 637
 638                 r = kern_path(syspath, LOOKUP_FOLLOW, &path);
 639                 kfree(syspath);
 640                 if (r)
 641                         return r;
 642
 643                 inode = path.dentry->d_inode;
 644
 645                 r = inode_permission(inode, MAY_READ | MAY_WRITE | MAY_ACCESS);
 646                 path_put(&path);
 647                 if (r)
 648                         return r;
 649
 650                 bar_found = true;
 651         }
 652
 653         /* If no resources, probably something special */
 654         if (!bar_found)
 655                 return -EPERM;
 656
 657         return 0;
 658 #else
 659         return -EINVAL; /* No way to control the device without sysfs */
 660 #endif
 661 }
 662
 663 static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
 664                                       struct kvm_assigned_pci_dev *assigned_dev)
 665 {
 666         int r = 0, idx;
 667         struct kvm_assigned_dev_kernel *match;
 668         struct pci_dev *dev;
 669
 670         if (!(assigned_dev->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU))
 671                 return -EINVAL;
 672
 673         mutex_lock(&kvm->lock);
 674         idx = srcu_read_lock(&kvm->srcu);
 675
 676         match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
 677                                       assigned_dev->assigned_dev_id);
 678         if (match) {
 679                 /* device already assigned */
 680                 r = -EEXIST;
 681                 goto out;
 682         }
 683
 684         match = kzalloc(sizeof(struct kvm_assigned_dev_kernel), GFP_KERNEL);
 685         if (match == NULL) {
 686                 printk(KERN_INFO "%s: Couldn't allocate memory\n",
 687                        __func__);
 688                 r = -ENOMEM;
 689                 goto out;
 690         }
 691         dev = pci_get_domain_bus_and_slot(assigned_dev->segnr,
 692                                    assigned_dev->busnr,
 693                                    assigned_dev->devfn);
 694         if (!dev) {
 695                 printk(KERN_INFO "%s: host device not found\n", __func__);
 696                 r = -EINVAL;
 697                 goto out_free;
 698         }
 699
 700         /* Don't allow bridges to be assigned */
 701         if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL) {
 702                 r = -EPERM;
 703                 goto out_put;
 704         }
 705
 706         r = probe_sysfs_permissions(dev);
 707         if (r)
 708                 goto out_put;
 709
 710         if (pci_enable_device(dev)) {
 711                 printk(KERN_INFO "%s: Could not enable PCI device\n", __func__);
 712                 r = -EBUSY;
 713                 goto out_put;
 714         }
 715         r = pci_request_regions(dev, "kvm_assigned_device");
 716         if (r) {
 717                 printk(KERN_INFO "%s: Could not get access to device regions\n",
 718                        __func__);
 719                 goto out_disable;
 720         }
 721
 722         pci_reset_function(dev);
 723         pci_save_state(dev);
 724         match->pci_saved_state = pci_store_saved_state(dev);
 725         if (!match->pci_saved_state)
 726                 printk(KERN_DEBUG "%s: Couldn't store %s saved state\n",
 727                        __func__, dev_name(&dev->dev));
 728
 729         if (!pci_intx_mask_supported(dev))
 730                 assigned_dev->flags &= ~KVM_DEV_ASSIGN_PCI_2_3;
 731
 732         match->assigned_dev_id = assigned_dev->assigned_dev_id;
 733         match->host_segnr = assigned_dev->segnr;
 734         match->host_busnr = assigned_dev->busnr;
 735         match->host_devfn = assigned_dev->devfn;
 736         match->flags = assigned_dev->flags;
 737         match->dev = dev;
 738         spin_lock_init(&match->intx_lock);
 739         spin_lock_init(&match->intx_mask_lock);
 740         match->irq_source_id = -1;
 741         match->kvm = kvm;
 742         match->ack_notifier.irq_acked = kvm_assigned_dev_ack_irq;
 743
 744         list_add(&match->list, &kvm->arch.assigned_dev_head);
 745
 746         if (!kvm->arch.iommu_domain) {
 747                 r = kvm_iommu_map_guest(kvm);
 748                 if (r)
 749                         goto out_list_del;
 750         }
 751         r = kvm_assign_device(kvm, match);
 752         if (r)
 753                 goto out_list_del;
 754
 755 out:
 756         srcu_read_unlock(&kvm->srcu, idx);
 757         mutex_unlock(&kvm->lock);
 758         return r;
 759 out_list_del:
 760         if (pci_load_and_free_saved_state(dev, &match->pci_saved_state))
 761                 printk(KERN_INFO "%s: Couldn't reload %s saved state\n",
 762                        __func__, dev_name(&dev->dev));
 763         list_del(&match->list);
 764         pci_release_regions(dev);
 765 out_disable:
 766         pci_disable_device(dev);
 767 out_put:
 768         pci_dev_put(dev);
 769 out_free:
 770         kfree(match);
 771         srcu_read_unlock(&kvm->srcu, idx);
 772         mutex_unlock(&kvm->lock);
 773         return r;
 774 }
 775
 776 static int kvm_vm_ioctl_deassign_device(struct kvm *kvm,
 777                 struct kvm_assigned_pci_dev *assigned_dev)
 778 {
 779         int r = 0;
 780         struct kvm_assigned_dev_kernel *match;
 781
 782         mutex_lock(&kvm->lock);
 783
 784         match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
 785                                       assigned_dev->assigned_dev_id);
 786         if (!match) {
 787                 printk(KERN_INFO "%s: device hasn't been assigned before, "
 788                   "so cannot be deassigned\n", __func__);
 789                 r = -EINVAL;
 790                 goto out;
 791         }
 792
 793         kvm_deassign_device(kvm, match);
 794
 795         kvm_free_assigned_device(kvm, match);
 796
 797 out:
 798         mutex_unlock(&kvm->lock);
 799         return r;
 800 }
 801
 802
 803 #ifdef __KVM_HAVE_MSIX
 804 static int kvm_vm_ioctl_set_msix_nr(struct kvm *kvm,
 805                                     struct kvm_assigned_msix_nr *entry_nr)
 806 {
 807         int r = 0;
 808         struct kvm_assigned_dev_kernel *adev;
 809
 810         mutex_lock(&kvm->lock);
 811
 812         adev = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
 813                                       entry_nr->assigned_dev_id);
 814         if (!adev) {
 815                 r = -EINVAL;
 816                 goto msix_nr_out;
 817         }
 818
 819         if (adev->entries_nr == 0) {
 820                 adev->entries_nr = entry_nr->entry_nr;
 821                 if (adev->entries_nr == 0 ||
 822                     adev->entries_nr > KVM_MAX_MSIX_PER_DEV) {
 823                         r = -EINVAL;
 824                         goto msix_nr_out;
 825                 }
 826
 827                 adev->host_msix_entries = kzalloc(sizeof(struct msix_entry) *
 828                                                 entry_nr->entry_nr,
 829                                                 GFP_KERNEL);
 830                 if (!adev->host_msix_entries) {
 831                         r = -ENOMEM;
 832                         goto msix_nr_out;
 833                 }
 834                 adev->guest_msix_entries =
 835                         kzalloc(sizeof(struct msix_entry) * entry_nr->entry_nr,
 836                                 GFP_KERNEL);
 837                 if (!adev->guest_msix_entries) {
 838                         kfree(adev->host_msix_entries);
 839                         r = -ENOMEM;
 840                         goto msix_nr_out;
 841                 }
 842         } else /* Not allowed set MSI-X number twice */
 843                 r = -EINVAL;
 844 msix_nr_out:
 845         mutex_unlock(&kvm->lock);
 846         return r;
 847 }
 848
 849 static int kvm_vm_ioctl_set_msix_entry(struct kvm *kvm,
 850                                        struct kvm_assigned_msix_entry *entry)
 851 {
 852         int r = 0, i;
 853         struct kvm_assigned_dev_kernel *adev;
 854
 855         mutex_lock(&kvm->lock);
 856
 857         adev = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
 858                                       entry->assigned_dev_id);
 859
 860         if (!adev) {
 861                 r = -EINVAL;
 862                 goto msix_entry_out;
 863         }
 864
 865         for (i = 0; i < adev->entries_nr; i++)
 866                 if (adev->guest_msix_entries[i].vector == 0 ||
 867                     adev->guest_msix_entries[i].entry == entry->entry) {
 868                         adev->guest_msix_entries[i].entry = entry->entry;
 869                         adev->guest_msix_entries[i].vector = entry->gsi;
 870                         adev->host_msix_entries[i].entry = entry->entry;
 871                         break;
 872                 }
 873         if (i == adev->entries_nr) {
 874                 r = -ENOSPC;
 875                 goto msix_entry_out;
 876         }
 877
 878 msix_entry_out:
 879         mutex_unlock(&kvm->lock);
 880
 881         return r;
 882 }
 883 #endif
 884
 885 static int kvm_vm_ioctl_set_pci_irq_mask(struct kvm *kvm,
 886                 struct kvm_assigned_pci_dev *assigned_dev)
 887 {
 888         int r = 0;
 889         struct kvm_assigned_dev_kernel *match;
 890
 891         mutex_lock(&kvm->lock);
 892
 893         match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
 894                                       assigned_dev->assigned_dev_id);
 895         if (!match) {
 896                 r = -ENODEV;
 897                 goto out;
 898         }
 899
 900         spin_lock(&match->intx_mask_lock);
 901
 902         match->flags &= ~KVM_DEV_ASSIGN_MASK_INTX;
 903         match->flags |= assigned_dev->flags & KVM_DEV_ASSIGN_MASK_INTX;
 904
 905         if (match->irq_requested_type & KVM_DEV_IRQ_GUEST_INTX) {
 906                 if (assigned_dev->flags & KVM_DEV_ASSIGN_MASK_INTX) {
 907                         kvm_set_irq(match->kvm, match->irq_source_id,
 908                                     match->guest_irq, 0, false);
 909                         /*
 910                          * Masking at hardware-level is performed on demand,
 911                          * i.e. when an IRQ actually arrives at the host.
 912                          */
 913                 } else if (!(assigned_dev->flags & KVM_DEV_ASSIGN_PCI_2_3)) {
 914                         /*
 915                          * Unmask the IRQ line if required. Unmasking at
 916                          * device level will be performed by user space.
 917                          */
 918                         spin_lock_irq(&match->intx_lock);
 919                         if (match->host_irq_disabled) {
 920                                 enable_irq(match->host_irq);
 921                                 match->host_irq_disabled = false;
 922                         }
 923                         spin_unlock_irq(&match->intx_lock);
 924                 }
 925         }
 926
 927         spin_unlock(&match->intx_mask_lock);
 928
 929 out:
 930         mutex_unlock(&kvm->lock);
 931         return r;
 932 }
 933
 934 long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl,
 935                                   unsigned long arg)
 936 {
 937         void __user *argp = (void __user *)arg;
 938         int r;
 939
 940         switch (ioctl) {
 941         case KVM_ASSIGN_PCI_DEVICE: {
 942                 struct kvm_assigned_pci_dev assigned_dev;
 943
 944                 r = -EFAULT;
 945                 if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
 946                         goto out;
 947                 r = kvm_vm_ioctl_assign_device(kvm, &assigned_dev);
 948                 if (r)
 949                         goto out;
 950                 break;
 951         }
 952         case KVM_ASSIGN_IRQ: {
 953                 r = -EOPNOTSUPP;
 954                 break;
 955         }
 956         case KVM_ASSIGN_DEV_IRQ: {
 957                 struct kvm_assigned_irq assigned_irq;
 958
 959                 r = -EFAULT;
 960                 if (copy_from_user(&assigned_irq, argp, sizeof assigned_irq))
 961                         goto out;
 962                 r = kvm_vm_ioctl_assign_irq(kvm, &assigned_irq);
 963                 if (r)
 964                         goto out;
 965                 break;
 966         }
 967         case KVM_DEASSIGN_DEV_IRQ: {
 968                 struct kvm_assigned_irq assigned_irq;
 969
 970                 r = -EFAULT;
 971                 if (copy_from_user(&assigned_irq, argp, sizeof assigned_irq))
 972                         goto out;
 973                 r = kvm_vm_ioctl_deassign_dev_irq(kvm, &assigned_irq);
 974                 if (r)
 975                         goto out;
 976                 break;
 977         }
 978         case KVM_DEASSIGN_PCI_DEVICE: {
 979                 struct kvm_assigned_pci_dev assigned_dev;
 980
 981                 r = -EFAULT;
 982                 if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
 983                         goto out;
 984                 r = kvm_vm_ioctl_deassign_device(kvm, &assigned_dev);
 985                 if (r)
 986                         goto out;
 987                 break;
 988         }
 989 #ifdef __KVM_HAVE_MSIX
 990         case KVM_ASSIGN_SET_MSIX_NR: {
 991                 struct kvm_assigned_msix_nr entry_nr;
 992                 r = -EFAULT;
 993                 if (copy_from_user(&entry_nr, argp, sizeof entry_nr))
 994                         goto out;
 995                 r = kvm_vm_ioctl_set_msix_nr(kvm, &entry_nr);
 996                 if (r)
 997                         goto out;
 998                 break;
 999         }
1000         case KVM_ASSIGN_SET_MSIX_ENTRY: {
1001                 struct kvm_assigned_msix_entry entry;
1002                 r = -EFAULT;
1003                 if (copy_from_user(&entry, argp, sizeof entry))
1004                         goto out;
1005                 r = kvm_vm_ioctl_set_msix_entry(kvm, &entry);
1006                 if (r)
1007                         goto out;
1008                 break;
1009         }
1010 #endif
1011         case KVM_ASSIGN_SET_INTX_MASK: {
1012                 struct kvm_assigned_pci_dev assigned_dev;
1013
1014                 r = -EFAULT;
1015                 if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
1016                         goto out;
1017                 r = kvm_vm_ioctl_set_pci_irq_mask(kvm, &assigned_dev);
1018                 break;
1019         }
1020         default:
1021                 r = -ENOTTY;
1022                 break;
1023         }
1024 out:
1025         return r;
1026 }