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TOMOYO Linux Cross Reference
Linux/arch/x86/kvm/assigned-dev.c

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  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 #include "assigned-dev.h"
 24 
 25 struct kvm_assigned_dev_kernel {
 26         struct kvm_irq_ack_notifier ack_notifier;
 27         struct list_head list;
 28         int assigned_dev_id;
 29         int host_segnr;
 30         int host_busnr;
 31         int host_devfn;
 32         unsigned int entries_nr;
 33         int host_irq;
 34         bool host_irq_disabled;
 35         bool pci_2_3;
 36         struct msix_entry *host_msix_entries;
 37         int guest_irq;
 38         struct msix_entry *guest_msix_entries;
 39         unsigned long irq_requested_type;
 40         int irq_source_id;
 41         int flags;
 42         struct pci_dev *dev;
 43         struct kvm *kvm;
 44         spinlock_t intx_lock;
 45         spinlock_t intx_mask_lock;
 46         char irq_name[32];
 47         struct pci_saved_state *pci_saved_state;
 48 };
 49 
 50 static struct kvm_assigned_dev_kernel *kvm_find_assigned_dev(struct list_head *head,
 51                                                       int assigned_dev_id)
 52 {
 53         struct list_head *ptr;
 54         struct kvm_assigned_dev_kernel *match;
 55 
 56         list_for_each(ptr, head) {
 57                 match = list_entry(ptr, struct kvm_assigned_dev_kernel, list);
 58                 if (match->assigned_dev_id == assigned_dev_id)
 59                         return match;
 60         }
 61         return NULL;
 62 }
 63 
 64 static int find_index_from_host_irq(struct kvm_assigned_dev_kernel
 65                                     *assigned_dev, int irq)
 66 {
 67         int i, index;
 68         struct msix_entry *host_msix_entries;
 69 
 70         host_msix_entries = assigned_dev->host_msix_entries;
 71 
 72         index = -1;
 73         for (i = 0; i < assigned_dev->entries_nr; i++)
 74                 if (irq == host_msix_entries[i].vector) {
 75                         index = i;
 76                         break;
 77                 }
 78         if (index < 0)
 79                 printk(KERN_WARNING "Fail to find correlated MSI-X entry!\n");
 80 
 81         return index;
 82 }
 83 
 84 static irqreturn_t kvm_assigned_dev_intx(int irq, void *dev_id)
 85 {
 86         struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
 87         int ret;
 88 
 89         spin_lock(&assigned_dev->intx_lock);
 90         if (pci_check_and_mask_intx(assigned_dev->dev)) {
 91                 assigned_dev->host_irq_disabled = true;
 92                 ret = IRQ_WAKE_THREAD;
 93         } else
 94                 ret = IRQ_NONE;
 95         spin_unlock(&assigned_dev->intx_lock);
 96 
 97         return ret;
 98 }
 99 
100 static void
101 kvm_assigned_dev_raise_guest_irq(struct kvm_assigned_dev_kernel *assigned_dev,
102                                  int vector)
103 {
104         if (unlikely(assigned_dev->irq_requested_type &
105                      KVM_DEV_IRQ_GUEST_INTX)) {
106                 spin_lock(&assigned_dev->intx_mask_lock);
107                 if (!(assigned_dev->flags & KVM_DEV_ASSIGN_MASK_INTX))
108                         kvm_set_irq(assigned_dev->kvm,
109                                     assigned_dev->irq_source_id, vector, 1,
110                                     false);
111                 spin_unlock(&assigned_dev->intx_mask_lock);
112         } else
113                 kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id,
114                             vector, 1, false);
115 }
116 
117 static irqreturn_t kvm_assigned_dev_thread_intx(int irq, void *dev_id)
118 {
119         struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
120 
121         if (!(assigned_dev->flags & KVM_DEV_ASSIGN_PCI_2_3)) {
122                 spin_lock_irq(&assigned_dev->intx_lock);
123                 disable_irq_nosync(irq);
124                 assigned_dev->host_irq_disabled = true;
125                 spin_unlock_irq(&assigned_dev->intx_lock);
126         }
127 
128         kvm_assigned_dev_raise_guest_irq(assigned_dev,
129                                          assigned_dev->guest_irq);
130 
131         return IRQ_HANDLED;
132 }
133 
134 #ifdef __KVM_HAVE_MSI
135 static irqreturn_t kvm_assigned_dev_msi(int irq, void *dev_id)
136 {
137         struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
138         int ret = kvm_set_irq_inatomic(assigned_dev->kvm,
139                                        assigned_dev->irq_source_id,
140                                        assigned_dev->guest_irq, 1);
141         return unlikely(ret == -EWOULDBLOCK) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
142 }
143 
144 static irqreturn_t kvm_assigned_dev_thread_msi(int irq, void *dev_id)
145 {
146         struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
147 
148         kvm_assigned_dev_raise_guest_irq(assigned_dev,
149                                          assigned_dev->guest_irq);
150 
151         return IRQ_HANDLED;
152 }
153 #endif
154 
155 #ifdef __KVM_HAVE_MSIX
156 static irqreturn_t kvm_assigned_dev_msix(int irq, void *dev_id)
157 {
158         struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
159         int index = find_index_from_host_irq(assigned_dev, irq);
160         u32 vector;
161         int ret = 0;
162 
163         if (index >= 0) {
164                 vector = assigned_dev->guest_msix_entries[index].vector;
165                 ret = kvm_set_irq_inatomic(assigned_dev->kvm,
166                                            assigned_dev->irq_source_id,
167                                            vector, 1);
168         }
169 
170         return unlikely(ret == -EWOULDBLOCK) ? IRQ_WAKE_THREAD : IRQ_HANDLED;
171 }
172 
173 static irqreturn_t kvm_assigned_dev_thread_msix(int irq, void *dev_id)
174 {
175         struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
176         int index = find_index_from_host_irq(assigned_dev, irq);
177         u32 vector;
178 
179         if (index >= 0) {
180                 vector = assigned_dev->guest_msix_entries[index].vector;
181                 kvm_assigned_dev_raise_guest_irq(assigned_dev, vector);
182         }
183 
184         return IRQ_HANDLED;
185 }
186 #endif
187 
188 /* Ack the irq line for an assigned device */
189 static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
190 {
191         struct kvm_assigned_dev_kernel *dev =
192                 container_of(kian, struct kvm_assigned_dev_kernel,
193                              ack_notifier);
194 
195         kvm_set_irq(dev->kvm, dev->irq_source_id, dev->guest_irq, 0, false);
196 
197         spin_lock(&dev->intx_mask_lock);
198 
199         if (!(dev->flags & KVM_DEV_ASSIGN_MASK_INTX)) {
200                 bool reassert = false;
201 
202                 spin_lock_irq(&dev->intx_lock);
203                 /*
204                  * The guest IRQ may be shared so this ack can come from an
205                  * IRQ for another guest device.
206                  */
207                 if (dev->host_irq_disabled) {
208                         if (!(dev->flags & KVM_DEV_ASSIGN_PCI_2_3))
209                                 enable_irq(dev->host_irq);
210                         else if (!pci_check_and_unmask_intx(dev->dev))
211                                 reassert = true;
212                         dev->host_irq_disabled = reassert;
213                 }
214                 spin_unlock_irq(&dev->intx_lock);
215 
216                 if (reassert)
217                         kvm_set_irq(dev->kvm, dev->irq_source_id,
218                                     dev->guest_irq, 1, false);
219         }
220 
221         spin_unlock(&dev->intx_mask_lock);
222 }
223 
224 static void deassign_guest_irq(struct kvm *kvm,
225                                struct kvm_assigned_dev_kernel *assigned_dev)
226 {
227         if (assigned_dev->ack_notifier.gsi != -1)
228                 kvm_unregister_irq_ack_notifier(kvm,
229                                                 &assigned_dev->ack_notifier);
230 
231         kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id,
232                     assigned_dev->guest_irq, 0, false);
233 
234         if (assigned_dev->irq_source_id != -1)
235                 kvm_free_irq_source_id(kvm, assigned_dev->irq_source_id);
236         assigned_dev->irq_source_id = -1;
237         assigned_dev->irq_requested_type &= ~(KVM_DEV_IRQ_GUEST_MASK);
238 }
239 
240 /* The function implicit hold kvm->lock mutex due to cancel_work_sync() */
241 static void deassign_host_irq(struct kvm *kvm,
242                               struct kvm_assigned_dev_kernel *assigned_dev)
243 {
244         /*
245          * We disable irq here to prevent further events.
246          *
247          * Notice this maybe result in nested disable if the interrupt type is
248          * INTx, but it's OK for we are going to free it.
249          *
250          * If this function is a part of VM destroy, please ensure that till
251          * now, the kvm state is still legal for probably we also have to wait
252          * on a currently running IRQ handler.
253          */
254         if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) {
255                 int i;
256                 for (i = 0; i < assigned_dev->entries_nr; i++)
257                         disable_irq(assigned_dev->host_msix_entries[i].vector);
258 
259                 for (i = 0; i < assigned_dev->entries_nr; i++)
260                         free_irq(assigned_dev->host_msix_entries[i].vector,
261                                  assigned_dev);
262 
263                 assigned_dev->entries_nr = 0;
264                 kfree(assigned_dev->host_msix_entries);
265                 kfree(assigned_dev->guest_msix_entries);
266                 pci_disable_msix(assigned_dev->dev);
267         } else {
268                 /* Deal with MSI and INTx */
269                 if ((assigned_dev->irq_requested_type &
270                      KVM_DEV_IRQ_HOST_INTX) &&
271                     (assigned_dev->flags & KVM_DEV_ASSIGN_PCI_2_3)) {
272                         spin_lock_irq(&assigned_dev->intx_lock);
273                         pci_intx(assigned_dev->dev, false);
274                         spin_unlock_irq(&assigned_dev->intx_lock);
275                         synchronize_irq(assigned_dev->host_irq);
276                 } else
277                         disable_irq(assigned_dev->host_irq);
278 
279                 free_irq(assigned_dev->host_irq, assigned_dev);
280 
281                 if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSI)
282                         pci_disable_msi(assigned_dev->dev);
283         }
284 
285         assigned_dev->irq_requested_type &= ~(KVM_DEV_IRQ_HOST_MASK);
286 }
287 
288 static int kvm_deassign_irq(struct kvm *kvm,
289                             struct kvm_assigned_dev_kernel *assigned_dev,
290                             unsigned long irq_requested_type)
291 {
292         unsigned long guest_irq_type, host_irq_type;
293 
294         if (!irqchip_in_kernel(kvm))
295                 return -EINVAL;
296         /* no irq assignment to deassign */
297         if (!assigned_dev->irq_requested_type)
298                 return -ENXIO;
299 
300         host_irq_type = irq_requested_type & KVM_DEV_IRQ_HOST_MASK;
301         guest_irq_type = irq_requested_type & KVM_DEV_IRQ_GUEST_MASK;
302 
303         if (host_irq_type)
304                 deassign_host_irq(kvm, assigned_dev);
305         if (guest_irq_type)
306                 deassign_guest_irq(kvm, assigned_dev);
307 
308         return 0;
309 }
310 
311 static void kvm_free_assigned_irq(struct kvm *kvm,
312                                   struct kvm_assigned_dev_kernel *assigned_dev)
313 {
314         kvm_deassign_irq(kvm, assigned_dev, assigned_dev->irq_requested_type);
315 }
316 
317 static void kvm_free_assigned_device(struct kvm *kvm,
318                                      struct kvm_assigned_dev_kernel
319                                      *assigned_dev)
320 {
321         kvm_free_assigned_irq(kvm, assigned_dev);
322 
323         pci_reset_function(assigned_dev->dev);
324         if (pci_load_and_free_saved_state(assigned_dev->dev,
325                                           &assigned_dev->pci_saved_state))
326                 printk(KERN_INFO "%s: Couldn't reload %s saved state\n",
327                        __func__, dev_name(&assigned_dev->dev->dev));
328         else
329                 pci_restore_state(assigned_dev->dev);
330 
331         pci_clear_dev_assigned(assigned_dev->dev);
332 
333         pci_release_regions(assigned_dev->dev);
334         pci_disable_device(assigned_dev->dev);
335         pci_dev_put(assigned_dev->dev);
336 
337         list_del(&assigned_dev->list);
338         kfree(assigned_dev);
339 }
340 
341 void kvm_free_all_assigned_devices(struct kvm *kvm)
342 {
343         struct list_head *ptr, *ptr2;
344         struct kvm_assigned_dev_kernel *assigned_dev;
345 
346         list_for_each_safe(ptr, ptr2, &kvm->arch.assigned_dev_head) {
347                 assigned_dev = list_entry(ptr,
348                                           struct kvm_assigned_dev_kernel,
349                                           list);
350 
351                 kvm_free_assigned_device(kvm, assigned_dev);
352         }
353 }
354 
355 static int assigned_device_enable_host_intx(struct kvm *kvm,
356                                             struct kvm_assigned_dev_kernel *dev)
357 {
358         irq_handler_t irq_handler;
359         unsigned long flags;
360 
361         dev->host_irq = dev->dev->irq;
362 
363         /*
364          * We can only share the IRQ line with other host devices if we are
365          * able to disable the IRQ source at device-level - independently of
366          * the guest driver. Otherwise host devices may suffer from unbounded
367          * IRQ latencies when the guest keeps the line asserted.
368          */
369         if (dev->flags & KVM_DEV_ASSIGN_PCI_2_3) {
370                 irq_handler = kvm_assigned_dev_intx;
371                 flags = IRQF_SHARED;
372         } else {
373                 irq_handler = NULL;
374                 flags = IRQF_ONESHOT;
375         }
376         if (request_threaded_irq(dev->host_irq, irq_handler,
377                                  kvm_assigned_dev_thread_intx, flags,
378                                  dev->irq_name, dev))
379                 return -EIO;
380 
381         if (dev->flags & KVM_DEV_ASSIGN_PCI_2_3) {
382                 spin_lock_irq(&dev->intx_lock);
383                 pci_intx(dev->dev, true);
384                 spin_unlock_irq(&dev->intx_lock);
385         }
386         return 0;
387 }
388 
389 #ifdef __KVM_HAVE_MSI
390 static int assigned_device_enable_host_msi(struct kvm *kvm,
391                                            struct kvm_assigned_dev_kernel *dev)
392 {
393         int r;
394 
395         if (!dev->dev->msi_enabled) {
396                 r = pci_enable_msi(dev->dev);
397                 if (r)
398                         return r;
399         }
400 
401         dev->host_irq = dev->dev->irq;
402         if (request_threaded_irq(dev->host_irq, kvm_assigned_dev_msi,
403                                  kvm_assigned_dev_thread_msi, 0,
404                                  dev->irq_name, dev)) {
405                 pci_disable_msi(dev->dev);
406                 return -EIO;
407         }
408 
409         return 0;
410 }
411 #endif
412 
413 #ifdef __KVM_HAVE_MSIX
414 static int assigned_device_enable_host_msix(struct kvm *kvm,
415                                             struct kvm_assigned_dev_kernel *dev)
416 {
417         int i, r = -EINVAL;
418 
419         /* host_msix_entries and guest_msix_entries should have been
420          * initialized */
421         if (dev->entries_nr == 0)
422                 return r;
423 
424         r = pci_enable_msix_exact(dev->dev,
425                                   dev->host_msix_entries, dev->entries_nr);
426         if (r)
427                 return r;
428 
429         for (i = 0; i < dev->entries_nr; i++) {
430                 r = request_threaded_irq(dev->host_msix_entries[i].vector,
431                                          kvm_assigned_dev_msix,
432                                          kvm_assigned_dev_thread_msix,
433                                          0, dev->irq_name, dev);
434                 if (r)
435                         goto err;
436         }
437 
438         return 0;
439 err:
440         for (i -= 1; i >= 0; i--)
441                 free_irq(dev->host_msix_entries[i].vector, dev);
442         pci_disable_msix(dev->dev);
443         return r;
444 }
445 
446 #endif
447 
448 static int assigned_device_enable_guest_intx(struct kvm *kvm,
449                                 struct kvm_assigned_dev_kernel *dev,
450                                 struct kvm_assigned_irq *irq)
451 {
452         dev->guest_irq = irq->guest_irq;
453         dev->ack_notifier.gsi = irq->guest_irq;
454         return 0;
455 }
456 
457 #ifdef __KVM_HAVE_MSI
458 static int assigned_device_enable_guest_msi(struct kvm *kvm,
459                         struct kvm_assigned_dev_kernel *dev,
460                         struct kvm_assigned_irq *irq)
461 {
462         dev->guest_irq = irq->guest_irq;
463         dev->ack_notifier.gsi = -1;
464         return 0;
465 }
466 #endif
467 
468 #ifdef __KVM_HAVE_MSIX
469 static int assigned_device_enable_guest_msix(struct kvm *kvm,
470                         struct kvm_assigned_dev_kernel *dev,
471                         struct kvm_assigned_irq *irq)
472 {
473         dev->guest_irq = irq->guest_irq;
474         dev->ack_notifier.gsi = -1;
475         return 0;
476 }
477 #endif
478 
479 static int assign_host_irq(struct kvm *kvm,
480                            struct kvm_assigned_dev_kernel *dev,
481                            __u32 host_irq_type)
482 {
483         int r = -EEXIST;
484 
485         if (dev->irq_requested_type & KVM_DEV_IRQ_HOST_MASK)
486                 return r;
487 
488         snprintf(dev->irq_name, sizeof(dev->irq_name), "kvm:%s",
489                  pci_name(dev->dev));
490 
491         switch (host_irq_type) {
492         case KVM_DEV_IRQ_HOST_INTX:
493                 r = assigned_device_enable_host_intx(kvm, dev);
494                 break;
495 #ifdef __KVM_HAVE_MSI
496         case KVM_DEV_IRQ_HOST_MSI:
497                 r = assigned_device_enable_host_msi(kvm, dev);
498                 break;
499 #endif
500 #ifdef __KVM_HAVE_MSIX
501         case KVM_DEV_IRQ_HOST_MSIX:
502                 r = assigned_device_enable_host_msix(kvm, dev);
503                 break;
504 #endif
505         default:
506                 r = -EINVAL;
507         }
508         dev->host_irq_disabled = false;
509 
510         if (!r)
511                 dev->irq_requested_type |= host_irq_type;
512 
513         return r;
514 }
515 
516 static int assign_guest_irq(struct kvm *kvm,
517                             struct kvm_assigned_dev_kernel *dev,
518                             struct kvm_assigned_irq *irq,
519                             unsigned long guest_irq_type)
520 {
521         int id;
522         int r = -EEXIST;
523 
524         if (dev->irq_requested_type & KVM_DEV_IRQ_GUEST_MASK)
525                 return r;
526 
527         id = kvm_request_irq_source_id(kvm);
528         if (id < 0)
529                 return id;
530 
531         dev->irq_source_id = id;
532 
533         switch (guest_irq_type) {
534         case KVM_DEV_IRQ_GUEST_INTX:
535                 r = assigned_device_enable_guest_intx(kvm, dev, irq);
536                 break;
537 #ifdef __KVM_HAVE_MSI
538         case KVM_DEV_IRQ_GUEST_MSI:
539                 r = assigned_device_enable_guest_msi(kvm, dev, irq);
540                 break;
541 #endif
542 #ifdef __KVM_HAVE_MSIX
543         case KVM_DEV_IRQ_GUEST_MSIX:
544                 r = assigned_device_enable_guest_msix(kvm, dev, irq);
545                 break;
546 #endif
547         default:
548                 r = -EINVAL;
549         }
550 
551         if (!r) {
552                 dev->irq_requested_type |= guest_irq_type;
553                 if (dev->ack_notifier.gsi != -1)
554                         kvm_register_irq_ack_notifier(kvm, &dev->ack_notifier);
555         } else {
556                 kvm_free_irq_source_id(kvm, dev->irq_source_id);
557                 dev->irq_source_id = -1;
558         }
559 
560         return r;
561 }
562 
563 /* TODO Deal with KVM_DEV_IRQ_ASSIGNED_MASK_MSIX */
564 static int kvm_vm_ioctl_assign_irq(struct kvm *kvm,
565                                    struct kvm_assigned_irq *assigned_irq)
566 {
567         int r = -EINVAL;
568         struct kvm_assigned_dev_kernel *match;
569         unsigned long host_irq_type, guest_irq_type;
570 
571         if (!irqchip_in_kernel(kvm))
572                 return r;
573 
574         mutex_lock(&kvm->lock);
575         r = -ENODEV;
576         match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
577                                       assigned_irq->assigned_dev_id);
578         if (!match)
579                 goto out;
580 
581         host_irq_type = (assigned_irq->flags & KVM_DEV_IRQ_HOST_MASK);
582         guest_irq_type = (assigned_irq->flags & KVM_DEV_IRQ_GUEST_MASK);
583 
584         r = -EINVAL;
585         /* can only assign one type at a time */
586         if (hweight_long(host_irq_type) > 1)
587                 goto out;
588         if (hweight_long(guest_irq_type) > 1)
589                 goto out;
590         if (host_irq_type == 0 && guest_irq_type == 0)
591                 goto out;
592 
593         r = 0;
594         if (host_irq_type)
595                 r = assign_host_irq(kvm, match, host_irq_type);
596         if (r)
597                 goto out;
598 
599         if (guest_irq_type)
600                 r = assign_guest_irq(kvm, match, assigned_irq, guest_irq_type);
601 out:
602         mutex_unlock(&kvm->lock);
603         return r;
604 }
605 
606 static int kvm_vm_ioctl_deassign_dev_irq(struct kvm *kvm,
607                                          struct kvm_assigned_irq
608                                          *assigned_irq)
609 {
610         int r = -ENODEV;
611         struct kvm_assigned_dev_kernel *match;
612         unsigned long irq_type;
613 
614         mutex_lock(&kvm->lock);
615 
616         match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
617                                       assigned_irq->assigned_dev_id);
618         if (!match)
619                 goto out;
620 
621         irq_type = assigned_irq->flags & (KVM_DEV_IRQ_HOST_MASK |
622                                           KVM_DEV_IRQ_GUEST_MASK);
623         r = kvm_deassign_irq(kvm, match, irq_type);
624 out:
625         mutex_unlock(&kvm->lock);
626         return r;
627 }
628 
629 /*
630  * We want to test whether the caller has been granted permissions to
631  * use this device.  To be able to configure and control the device,
632  * the user needs access to PCI configuration space and BAR resources.
633  * These are accessed through PCI sysfs.  PCI config space is often
634  * passed to the process calling this ioctl via file descriptor, so we
635  * can't rely on access to that file.  We can check for permissions
636  * on each of the BAR resource files, which is a pretty clear
637  * indicator that the user has been granted access to the device.
638  */
639 static int probe_sysfs_permissions(struct pci_dev *dev)
640 {
641 #ifdef CONFIG_SYSFS
642         int i;
643         bool bar_found = false;
644 
645         for (i = PCI_STD_RESOURCES; i <= PCI_STD_RESOURCE_END; i++) {
646                 char *kpath, *syspath;
647                 struct path path;
648                 struct inode *inode;
649                 int r;
650 
651                 if (!pci_resource_len(dev, i))
652                         continue;
653 
654                 kpath = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
655                 if (!kpath)
656                         return -ENOMEM;
657 
658                 /* Per sysfs-rules, sysfs is always at /sys */
659                 syspath = kasprintf(GFP_KERNEL, "/sys%s/resource%d", kpath, i);
660                 kfree(kpath);
661                 if (!syspath)
662                         return -ENOMEM;
663 
664                 r = kern_path(syspath, LOOKUP_FOLLOW, &path);
665                 kfree(syspath);
666                 if (r)
667                         return r;
668 
669                 inode = path.dentry->d_inode;
670 
671                 r = inode_permission(inode, MAY_READ | MAY_WRITE | MAY_ACCESS);
672                 path_put(&path);
673                 if (r)
674                         return r;
675 
676                 bar_found = true;
677         }
678 
679         /* If no resources, probably something special */
680         if (!bar_found)
681                 return -EPERM;
682 
683         return 0;
684 #else
685         return -EINVAL; /* No way to control the device without sysfs */
686 #endif
687 }
688 
689 static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
690                                       struct kvm_assigned_pci_dev *assigned_dev)
691 {
692         int r = 0, idx;
693         struct kvm_assigned_dev_kernel *match;
694         struct pci_dev *dev;
695 
696         if (!(assigned_dev->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU))
697                 return -EINVAL;
698 
699         mutex_lock(&kvm->lock);
700         idx = srcu_read_lock(&kvm->srcu);
701 
702         match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
703                                       assigned_dev->assigned_dev_id);
704         if (match) {
705                 /* device already assigned */
706                 r = -EEXIST;
707                 goto out;
708         }
709 
710         match = kzalloc(sizeof(struct kvm_assigned_dev_kernel), GFP_KERNEL);
711         if (match == NULL) {
712                 printk(KERN_INFO "%s: Couldn't allocate memory\n",
713                        __func__);
714                 r = -ENOMEM;
715                 goto out;
716         }
717         dev = pci_get_domain_bus_and_slot(assigned_dev->segnr,
718                                    assigned_dev->busnr,
719                                    assigned_dev->devfn);
720         if (!dev) {
721                 printk(KERN_INFO "%s: host device not found\n", __func__);
722                 r = -EINVAL;
723                 goto out_free;
724         }
725 
726         /* Don't allow bridges to be assigned */
727         if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL) {
728                 r = -EPERM;
729                 goto out_put;
730         }
731 
732         r = probe_sysfs_permissions(dev);
733         if (r)
734                 goto out_put;
735 
736         if (pci_enable_device(dev)) {
737                 printk(KERN_INFO "%s: Could not enable PCI device\n", __func__);
738                 r = -EBUSY;
739                 goto out_put;
740         }
741         r = pci_request_regions(dev, "kvm_assigned_device");
742         if (r) {
743                 printk(KERN_INFO "%s: Could not get access to device regions\n",
744                        __func__);
745                 goto out_disable;
746         }
747 
748         pci_reset_function(dev);
749         pci_save_state(dev);
750         match->pci_saved_state = pci_store_saved_state(dev);
751         if (!match->pci_saved_state)
752                 printk(KERN_DEBUG "%s: Couldn't store %s saved state\n",
753                        __func__, dev_name(&dev->dev));
754 
755         if (!pci_intx_mask_supported(dev))
756                 assigned_dev->flags &= ~KVM_DEV_ASSIGN_PCI_2_3;
757 
758         match->assigned_dev_id = assigned_dev->assigned_dev_id;
759         match->host_segnr = assigned_dev->segnr;
760         match->host_busnr = assigned_dev->busnr;
761         match->host_devfn = assigned_dev->devfn;
762         match->flags = assigned_dev->flags;
763         match->dev = dev;
764         spin_lock_init(&match->intx_lock);
765         spin_lock_init(&match->intx_mask_lock);
766         match->irq_source_id = -1;
767         match->kvm = kvm;
768         match->ack_notifier.irq_acked = kvm_assigned_dev_ack_irq;
769 
770         list_add(&match->list, &kvm->arch.assigned_dev_head);
771 
772         if (!kvm->arch.iommu_domain) {
773                 r = kvm_iommu_map_guest(kvm);
774                 if (r)
775                         goto out_list_del;
776         }
777         r = kvm_assign_device(kvm, match->dev);
778         if (r)
779                 goto out_list_del;
780 
781 out:
782         srcu_read_unlock(&kvm->srcu, idx);
783         mutex_unlock(&kvm->lock);
784         return r;
785 out_list_del:
786         if (pci_load_and_free_saved_state(dev, &match->pci_saved_state))
787                 printk(KERN_INFO "%s: Couldn't reload %s saved state\n",
788                        __func__, dev_name(&dev->dev));
789         list_del(&match->list);
790         pci_release_regions(dev);
791 out_disable:
792         pci_disable_device(dev);
793 out_put:
794         pci_dev_put(dev);
795 out_free:
796         kfree(match);
797         srcu_read_unlock(&kvm->srcu, idx);
798         mutex_unlock(&kvm->lock);
799         return r;
800 }
801 
802 static int kvm_vm_ioctl_deassign_device(struct kvm *kvm,
803                 struct kvm_assigned_pci_dev *assigned_dev)
804 {
805         int r = 0;
806         struct kvm_assigned_dev_kernel *match;
807 
808         mutex_lock(&kvm->lock);
809 
810         match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
811                                       assigned_dev->assigned_dev_id);
812         if (!match) {
813                 printk(KERN_INFO "%s: device hasn't been assigned before, "
814                   "so cannot be deassigned\n", __func__);
815                 r = -EINVAL;
816                 goto out;
817         }
818 
819         kvm_deassign_device(kvm, match->dev);
820 
821         kvm_free_assigned_device(kvm, match);
822 
823 out:
824         mutex_unlock(&kvm->lock);
825         return r;
826 }
827 
828 
829 #ifdef __KVM_HAVE_MSIX
830 static int kvm_vm_ioctl_set_msix_nr(struct kvm *kvm,
831                                     struct kvm_assigned_msix_nr *entry_nr)
832 {
833         int r = 0;
834         struct kvm_assigned_dev_kernel *adev;
835 
836         mutex_lock(&kvm->lock);
837 
838         adev = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
839                                       entry_nr->assigned_dev_id);
840         if (!adev) {
841                 r = -EINVAL;
842                 goto msix_nr_out;
843         }
844 
845         if (adev->entries_nr == 0) {
846                 adev->entries_nr = entry_nr->entry_nr;
847                 if (adev->entries_nr == 0 ||
848                     adev->entries_nr > KVM_MAX_MSIX_PER_DEV) {
849                         r = -EINVAL;
850                         goto msix_nr_out;
851                 }
852 
853                 adev->host_msix_entries = kzalloc(sizeof(struct msix_entry) *
854                                                 entry_nr->entry_nr,
855                                                 GFP_KERNEL);
856                 if (!adev->host_msix_entries) {
857                         r = -ENOMEM;
858                         goto msix_nr_out;
859                 }
860                 adev->guest_msix_entries =
861                         kzalloc(sizeof(struct msix_entry) * entry_nr->entry_nr,
862                                 GFP_KERNEL);
863                 if (!adev->guest_msix_entries) {
864                         kfree(adev->host_msix_entries);
865                         r = -ENOMEM;
866                         goto msix_nr_out;
867                 }
868         } else /* Not allowed set MSI-X number twice */
869                 r = -EINVAL;
870 msix_nr_out:
871         mutex_unlock(&kvm->lock);
872         return r;
873 }
874 
875 static int kvm_vm_ioctl_set_msix_entry(struct kvm *kvm,
876                                        struct kvm_assigned_msix_entry *entry)
877 {
878         int r = 0, i;
879         struct kvm_assigned_dev_kernel *adev;
880 
881         mutex_lock(&kvm->lock);
882 
883         adev = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
884                                       entry->assigned_dev_id);
885 
886         if (!adev) {
887                 r = -EINVAL;
888                 goto msix_entry_out;
889         }
890 
891         for (i = 0; i < adev->entries_nr; i++)
892                 if (adev->guest_msix_entries[i].vector == 0 ||
893                     adev->guest_msix_entries[i].entry == entry->entry) {
894                         adev->guest_msix_entries[i].entry = entry->entry;
895                         adev->guest_msix_entries[i].vector = entry->gsi;
896                         adev->host_msix_entries[i].entry = entry->entry;
897                         break;
898                 }
899         if (i == adev->entries_nr) {
900                 r = -ENOSPC;
901                 goto msix_entry_out;
902         }
903 
904 msix_entry_out:
905         mutex_unlock(&kvm->lock);
906 
907         return r;
908 }
909 #endif
910 
911 static int kvm_vm_ioctl_set_pci_irq_mask(struct kvm *kvm,
912                 struct kvm_assigned_pci_dev *assigned_dev)
913 {
914         int r = 0;
915         struct kvm_assigned_dev_kernel *match;
916 
917         mutex_lock(&kvm->lock);
918 
919         match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
920                                       assigned_dev->assigned_dev_id);
921         if (!match) {
922                 r = -ENODEV;
923                 goto out;
924         }
925 
926         spin_lock(&match->intx_mask_lock);
927 
928         match->flags &= ~KVM_DEV_ASSIGN_MASK_INTX;
929         match->flags |= assigned_dev->flags & KVM_DEV_ASSIGN_MASK_INTX;
930 
931         if (match->irq_requested_type & KVM_DEV_IRQ_GUEST_INTX) {
932                 if (assigned_dev->flags & KVM_DEV_ASSIGN_MASK_INTX) {
933                         kvm_set_irq(match->kvm, match->irq_source_id,
934                                     match->guest_irq, 0, false);
935                         /*
936                          * Masking at hardware-level is performed on demand,
937                          * i.e. when an IRQ actually arrives at the host.
938                          */
939                 } else if (!(assigned_dev->flags & KVM_DEV_ASSIGN_PCI_2_3)) {
940                         /*
941                          * Unmask the IRQ line if required. Unmasking at
942                          * device level will be performed by user space.
943                          */
944                         spin_lock_irq(&match->intx_lock);
945                         if (match->host_irq_disabled) {
946                                 enable_irq(match->host_irq);
947                                 match->host_irq_disabled = false;
948                         }
949                         spin_unlock_irq(&match->intx_lock);
950                 }
951         }
952 
953         spin_unlock(&match->intx_mask_lock);
954 
955 out:
956         mutex_unlock(&kvm->lock);
957         return r;
958 }
959 
960 long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl,
961                                   unsigned long arg)
962 {
963         void __user *argp = (void __user *)arg;
964         int r;
965 
966         switch (ioctl) {
967         case KVM_ASSIGN_PCI_DEVICE: {
968                 struct kvm_assigned_pci_dev assigned_dev;
969 
970                 r = -EFAULT;
971                 if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
972                         goto out;
973                 r = kvm_vm_ioctl_assign_device(kvm, &assigned_dev);
974                 if (r)
975                         goto out;
976                 break;
977         }
978         case KVM_ASSIGN_IRQ: {
979                 r = -EOPNOTSUPP;
980                 break;
981         }
982         case KVM_ASSIGN_DEV_IRQ: {
983                 struct kvm_assigned_irq assigned_irq;
984 
985                 r = -EFAULT;
986                 if (copy_from_user(&assigned_irq, argp, sizeof assigned_irq))
987                         goto out;
988                 r = kvm_vm_ioctl_assign_irq(kvm, &assigned_irq);
989                 if (r)
990                         goto out;
991                 break;
992         }
993         case KVM_DEASSIGN_DEV_IRQ: {
994                 struct kvm_assigned_irq assigned_irq;
995 
996                 r = -EFAULT;
997                 if (copy_from_user(&assigned_irq, argp, sizeof assigned_irq))
998                         goto out;
999                 r = kvm_vm_ioctl_deassign_dev_irq(kvm, &assigned_irq);
1000                 if (r)
1001                         goto out;
1002                 break;
1003         }
1004         case KVM_DEASSIGN_PCI_DEVICE: {
1005                 struct kvm_assigned_pci_dev assigned_dev;
1006 
1007                 r = -EFAULT;
1008                 if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
1009                         goto out;
1010                 r = kvm_vm_ioctl_deassign_device(kvm, &assigned_dev);
1011                 if (r)
1012                         goto out;
1013                 break;
1014         }
1015 #ifdef __KVM_HAVE_MSIX
1016         case KVM_ASSIGN_SET_MSIX_NR: {
1017                 struct kvm_assigned_msix_nr entry_nr;
1018                 r = -EFAULT;
1019                 if (copy_from_user(&entry_nr, argp, sizeof entry_nr))
1020                         goto out;
1021                 r = kvm_vm_ioctl_set_msix_nr(kvm, &entry_nr);
1022                 if (r)
1023                         goto out;
1024                 break;
1025         }
1026         case KVM_ASSIGN_SET_MSIX_ENTRY: {
1027                 struct kvm_assigned_msix_entry entry;
1028                 r = -EFAULT;
1029                 if (copy_from_user(&entry, argp, sizeof entry))
1030                         goto out;
1031                 r = kvm_vm_ioctl_set_msix_entry(kvm, &entry);
1032                 if (r)
1033                         goto out;
1034                 break;
1035         }
1036 #endif
1037         case KVM_ASSIGN_SET_INTX_MASK: {
1038                 struct kvm_assigned_pci_dev assigned_dev;
1039 
1040                 r = -EFAULT;
1041                 if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
1042                         goto out;
1043                 r = kvm_vm_ioctl_set_pci_irq_mask(kvm, &assigned_dev);
1044                 break;
1045         }
1046         default:
1047                 r = -ENOTTY;
1048                 break;
1049         }
1050 out:
1051         return r;
1052 }
1053 

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