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Linux/virt/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 
 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         assigned_dev->dev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
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(dev->dev, dev->host_msix_entries, dev->entries_nr);
399         if (r)
400                 return r;
401 
402         for (i = 0; i < dev->entries_nr; i++) {
403                 r = request_threaded_irq(dev->host_msix_entries[i].vector,
404                                          kvm_assigned_dev_msix,
405                                          kvm_assigned_dev_thread_msix,
406                                          0, dev->irq_name, dev);
407                 if (r)
408                         goto err;
409         }
410 
411         return 0;
412 err:
413         for (i -= 1; i >= 0; i--)
414                 free_irq(dev->host_msix_entries[i].vector, dev);
415         pci_disable_msix(dev->dev);
416         return r;
417 }
418 
419 #endif
420 
421 static int assigned_device_enable_guest_intx(struct kvm *kvm,
422                                 struct kvm_assigned_dev_kernel *dev,
423                                 struct kvm_assigned_irq *irq)
424 {
425         dev->guest_irq = irq->guest_irq;
426         dev->ack_notifier.gsi = irq->guest_irq;
427         return 0;
428 }
429 
430 #ifdef __KVM_HAVE_MSI
431 static int assigned_device_enable_guest_msi(struct kvm *kvm,
432                         struct kvm_assigned_dev_kernel *dev,
433                         struct kvm_assigned_irq *irq)
434 {
435         dev->guest_irq = irq->guest_irq;
436         dev->ack_notifier.gsi = -1;
437         return 0;
438 }
439 #endif
440 
441 #ifdef __KVM_HAVE_MSIX
442 static int assigned_device_enable_guest_msix(struct kvm *kvm,
443                         struct kvm_assigned_dev_kernel *dev,
444                         struct kvm_assigned_irq *irq)
445 {
446         dev->guest_irq = irq->guest_irq;
447         dev->ack_notifier.gsi = -1;
448         return 0;
449 }
450 #endif
451 
452 static int assign_host_irq(struct kvm *kvm,
453                            struct kvm_assigned_dev_kernel *dev,
454                            __u32 host_irq_type)
455 {
456         int r = -EEXIST;
457 
458         if (dev->irq_requested_type & KVM_DEV_IRQ_HOST_MASK)
459                 return r;
460 
461         snprintf(dev->irq_name, sizeof(dev->irq_name), "kvm:%s",
462                  pci_name(dev->dev));
463 
464         switch (host_irq_type) {
465         case KVM_DEV_IRQ_HOST_INTX:
466                 r = assigned_device_enable_host_intx(kvm, dev);
467                 break;
468 #ifdef __KVM_HAVE_MSI
469         case KVM_DEV_IRQ_HOST_MSI:
470                 r = assigned_device_enable_host_msi(kvm, dev);
471                 break;
472 #endif
473 #ifdef __KVM_HAVE_MSIX
474         case KVM_DEV_IRQ_HOST_MSIX:
475                 r = assigned_device_enable_host_msix(kvm, dev);
476                 break;
477 #endif
478         default:
479                 r = -EINVAL;
480         }
481         dev->host_irq_disabled = false;
482 
483         if (!r)
484                 dev->irq_requested_type |= host_irq_type;
485 
486         return r;
487 }
488 
489 static int assign_guest_irq(struct kvm *kvm,
490                             struct kvm_assigned_dev_kernel *dev,
491                             struct kvm_assigned_irq *irq,
492                             unsigned long guest_irq_type)
493 {
494         int id;
495         int r = -EEXIST;
496 
497         if (dev->irq_requested_type & KVM_DEV_IRQ_GUEST_MASK)
498                 return r;
499 
500         id = kvm_request_irq_source_id(kvm);
501         if (id < 0)
502                 return id;
503 
504         dev->irq_source_id = id;
505 
506         switch (guest_irq_type) {
507         case KVM_DEV_IRQ_GUEST_INTX:
508                 r = assigned_device_enable_guest_intx(kvm, dev, irq);
509                 break;
510 #ifdef __KVM_HAVE_MSI
511         case KVM_DEV_IRQ_GUEST_MSI:
512                 r = assigned_device_enable_guest_msi(kvm, dev, irq);
513                 break;
514 #endif
515 #ifdef __KVM_HAVE_MSIX
516         case KVM_DEV_IRQ_GUEST_MSIX:
517                 r = assigned_device_enable_guest_msix(kvm, dev, irq);
518                 break;
519 #endif
520         default:
521                 r = -EINVAL;
522         }
523 
524         if (!r) {
525                 dev->irq_requested_type |= guest_irq_type;
526                 if (dev->ack_notifier.gsi != -1)
527                         kvm_register_irq_ack_notifier(kvm, &dev->ack_notifier);
528         } else
529                 kvm_free_irq_source_id(kvm, dev->irq_source_id);
530 
531         return r;
532 }
533 
534 /* TODO Deal with KVM_DEV_IRQ_ASSIGNED_MASK_MSIX */
535 static int kvm_vm_ioctl_assign_irq(struct kvm *kvm,
536                                    struct kvm_assigned_irq *assigned_irq)
537 {
538         int r = -EINVAL;
539         struct kvm_assigned_dev_kernel *match;
540         unsigned long host_irq_type, guest_irq_type;
541 
542         if (!irqchip_in_kernel(kvm))
543                 return r;
544 
545         mutex_lock(&kvm->lock);
546         r = -ENODEV;
547         match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
548                                       assigned_irq->assigned_dev_id);
549         if (!match)
550                 goto out;
551 
552         host_irq_type = (assigned_irq->flags & KVM_DEV_IRQ_HOST_MASK);
553         guest_irq_type = (assigned_irq->flags & KVM_DEV_IRQ_GUEST_MASK);
554 
555         r = -EINVAL;
556         /* can only assign one type at a time */
557         if (hweight_long(host_irq_type) > 1)
558                 goto out;
559         if (hweight_long(guest_irq_type) > 1)
560                 goto out;
561         if (host_irq_type == 0 && guest_irq_type == 0)
562                 goto out;
563 
564         r = 0;
565         if (host_irq_type)
566                 r = assign_host_irq(kvm, match, host_irq_type);
567         if (r)
568                 goto out;
569 
570         if (guest_irq_type)
571                 r = assign_guest_irq(kvm, match, assigned_irq, guest_irq_type);
572 out:
573         mutex_unlock(&kvm->lock);
574         return r;
575 }
576 
577 static int kvm_vm_ioctl_deassign_dev_irq(struct kvm *kvm,
578                                          struct kvm_assigned_irq
579                                          *assigned_irq)
580 {
581         int r = -ENODEV;
582         struct kvm_assigned_dev_kernel *match;
583         unsigned long irq_type;
584 
585         mutex_lock(&kvm->lock);
586 
587         match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
588                                       assigned_irq->assigned_dev_id);
589         if (!match)
590                 goto out;
591 
592         irq_type = assigned_irq->flags & (KVM_DEV_IRQ_HOST_MASK |
593                                           KVM_DEV_IRQ_GUEST_MASK);
594         r = kvm_deassign_irq(kvm, match, irq_type);
595 out:
596         mutex_unlock(&kvm->lock);
597         return r;
598 }
599 
600 /*
601  * We want to test whether the caller has been granted permissions to
602  * use this device.  To be able to configure and control the device,
603  * the user needs access to PCI configuration space and BAR resources.
604  * These are accessed through PCI sysfs.  PCI config space is often
605  * passed to the process calling this ioctl via file descriptor, so we
606  * can't rely on access to that file.  We can check for permissions
607  * on each of the BAR resource files, which is a pretty clear
608  * indicator that the user has been granted access to the device.
609  */
610 static int probe_sysfs_permissions(struct pci_dev *dev)
611 {
612 #ifdef CONFIG_SYSFS
613         int i;
614         bool bar_found = false;
615 
616         for (i = PCI_STD_RESOURCES; i <= PCI_STD_RESOURCE_END; i++) {
617                 char *kpath, *syspath;
618                 struct path path;
619                 struct inode *inode;
620                 int r;
621 
622                 if (!pci_resource_len(dev, i))
623                         continue;
624 
625                 kpath = kobject_get_path(&dev->dev.kobj, GFP_KERNEL);
626                 if (!kpath)
627                         return -ENOMEM;
628 
629                 /* Per sysfs-rules, sysfs is always at /sys */
630                 syspath = kasprintf(GFP_KERNEL, "/sys%s/resource%d", kpath, i);
631                 kfree(kpath);
632                 if (!syspath)
633                         return -ENOMEM;
634 
635                 r = kern_path(syspath, LOOKUP_FOLLOW, &path);
636                 kfree(syspath);
637                 if (r)
638                         return r;
639 
640                 inode = path.dentry->d_inode;
641 
642                 r = inode_permission(inode, MAY_READ | MAY_WRITE | MAY_ACCESS);
643                 path_put(&path);
644                 if (r)
645                         return r;
646 
647                 bar_found = true;
648         }
649 
650         /* If no resources, probably something special */
651         if (!bar_found)
652                 return -EPERM;
653 
654         return 0;
655 #else
656         return -EINVAL; /* No way to control the device without sysfs */
657 #endif
658 }
659 
660 static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
661                                       struct kvm_assigned_pci_dev *assigned_dev)
662 {
663         int r = 0, idx;
664         struct kvm_assigned_dev_kernel *match;
665         struct pci_dev *dev;
666 
667         if (!(assigned_dev->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU))
668                 return -EINVAL;
669 
670         mutex_lock(&kvm->lock);
671         idx = srcu_read_lock(&kvm->srcu);
672 
673         match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
674                                       assigned_dev->assigned_dev_id);
675         if (match) {
676                 /* device already assigned */
677                 r = -EEXIST;
678                 goto out;
679         }
680 
681         match = kzalloc(sizeof(struct kvm_assigned_dev_kernel), GFP_KERNEL);
682         if (match == NULL) {
683                 printk(KERN_INFO "%s: Couldn't allocate memory\n",
684                        __func__);
685                 r = -ENOMEM;
686                 goto out;
687         }
688         dev = pci_get_domain_bus_and_slot(assigned_dev->segnr,
689                                    assigned_dev->busnr,
690                                    assigned_dev->devfn);
691         if (!dev) {
692                 printk(KERN_INFO "%s: host device not found\n", __func__);
693                 r = -EINVAL;
694                 goto out_free;
695         }
696 
697         /* Don't allow bridges to be assigned */
698         if (dev->hdr_type != PCI_HEADER_TYPE_NORMAL) {
699                 r = -EPERM;
700                 goto out_put;
701         }
702 
703         r = probe_sysfs_permissions(dev);
704         if (r)
705                 goto out_put;
706 
707         if (pci_enable_device(dev)) {
708                 printk(KERN_INFO "%s: Could not enable PCI device\n", __func__);
709                 r = -EBUSY;
710                 goto out_put;
711         }
712         r = pci_request_regions(dev, "kvm_assigned_device");
713         if (r) {
714                 printk(KERN_INFO "%s: Could not get access to device regions\n",
715                        __func__);
716                 goto out_disable;
717         }
718 
719         pci_reset_function(dev);
720         pci_save_state(dev);
721         match->pci_saved_state = pci_store_saved_state(dev);
722         if (!match->pci_saved_state)
723                 printk(KERN_DEBUG "%s: Couldn't store %s saved state\n",
724                        __func__, dev_name(&dev->dev));
725 
726         if (!pci_intx_mask_supported(dev))
727                 assigned_dev->flags &= ~KVM_DEV_ASSIGN_PCI_2_3;
728 
729         match->assigned_dev_id = assigned_dev->assigned_dev_id;
730         match->host_segnr = assigned_dev->segnr;
731         match->host_busnr = assigned_dev->busnr;
732         match->host_devfn = assigned_dev->devfn;
733         match->flags = assigned_dev->flags;
734         match->dev = dev;
735         spin_lock_init(&match->intx_lock);
736         spin_lock_init(&match->intx_mask_lock);
737         match->irq_source_id = -1;
738         match->kvm = kvm;
739         match->ack_notifier.irq_acked = kvm_assigned_dev_ack_irq;
740 
741         list_add(&match->list, &kvm->arch.assigned_dev_head);
742 
743         if (!kvm->arch.iommu_domain) {
744                 r = kvm_iommu_map_guest(kvm);
745                 if (r)
746                         goto out_list_del;
747         }
748         r = kvm_assign_device(kvm, match);
749         if (r)
750                 goto out_list_del;
751 
752 out:
753         srcu_read_unlock(&kvm->srcu, idx);
754         mutex_unlock(&kvm->lock);
755         return r;
756 out_list_del:
757         if (pci_load_and_free_saved_state(dev, &match->pci_saved_state))
758                 printk(KERN_INFO "%s: Couldn't reload %s saved state\n",
759                        __func__, dev_name(&dev->dev));
760         list_del(&match->list);
761         pci_release_regions(dev);
762 out_disable:
763         pci_disable_device(dev);
764 out_put:
765         pci_dev_put(dev);
766 out_free:
767         kfree(match);
768         srcu_read_unlock(&kvm->srcu, idx);
769         mutex_unlock(&kvm->lock);
770         return r;
771 }
772 
773 static int kvm_vm_ioctl_deassign_device(struct kvm *kvm,
774                 struct kvm_assigned_pci_dev *assigned_dev)
775 {
776         int r = 0;
777         struct kvm_assigned_dev_kernel *match;
778 
779         mutex_lock(&kvm->lock);
780 
781         match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
782                                       assigned_dev->assigned_dev_id);
783         if (!match) {
784                 printk(KERN_INFO "%s: device hasn't been assigned before, "
785                   "so cannot be deassigned\n", __func__);
786                 r = -EINVAL;
787                 goto out;
788         }
789 
790         kvm_deassign_device(kvm, match);
791 
792         kvm_free_assigned_device(kvm, match);
793 
794 out:
795         mutex_unlock(&kvm->lock);
796         return r;
797 }
798 
799 
800 #ifdef __KVM_HAVE_MSIX
801 static int kvm_vm_ioctl_set_msix_nr(struct kvm *kvm,
802                                     struct kvm_assigned_msix_nr *entry_nr)
803 {
804         int r = 0;
805         struct kvm_assigned_dev_kernel *adev;
806 
807         mutex_lock(&kvm->lock);
808 
809         adev = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
810                                       entry_nr->assigned_dev_id);
811         if (!adev) {
812                 r = -EINVAL;
813                 goto msix_nr_out;
814         }
815 
816         if (adev->entries_nr == 0) {
817                 adev->entries_nr = entry_nr->entry_nr;
818                 if (adev->entries_nr == 0 ||
819                     adev->entries_nr > KVM_MAX_MSIX_PER_DEV) {
820                         r = -EINVAL;
821                         goto msix_nr_out;
822                 }
823 
824                 adev->host_msix_entries = kzalloc(sizeof(struct msix_entry) *
825                                                 entry_nr->entry_nr,
826                                                 GFP_KERNEL);
827                 if (!adev->host_msix_entries) {
828                         r = -ENOMEM;
829                         goto msix_nr_out;
830                 }
831                 adev->guest_msix_entries =
832                         kzalloc(sizeof(struct msix_entry) * entry_nr->entry_nr,
833                                 GFP_KERNEL);
834                 if (!adev->guest_msix_entries) {
835                         kfree(adev->host_msix_entries);
836                         r = -ENOMEM;
837                         goto msix_nr_out;
838                 }
839         } else /* Not allowed set MSI-X number twice */
840                 r = -EINVAL;
841 msix_nr_out:
842         mutex_unlock(&kvm->lock);
843         return r;
844 }
845 
846 static int kvm_vm_ioctl_set_msix_entry(struct kvm *kvm,
847                                        struct kvm_assigned_msix_entry *entry)
848 {
849         int r = 0, i;
850         struct kvm_assigned_dev_kernel *adev;
851 
852         mutex_lock(&kvm->lock);
853 
854         adev = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
855                                       entry->assigned_dev_id);
856 
857         if (!adev) {
858                 r = -EINVAL;
859                 goto msix_entry_out;
860         }
861 
862         for (i = 0; i < adev->entries_nr; i++)
863                 if (adev->guest_msix_entries[i].vector == 0 ||
864                     adev->guest_msix_entries[i].entry == entry->entry) {
865                         adev->guest_msix_entries[i].entry = entry->entry;
866                         adev->guest_msix_entries[i].vector = entry->gsi;
867                         adev->host_msix_entries[i].entry = entry->entry;
868                         break;
869                 }
870         if (i == adev->entries_nr) {
871                 r = -ENOSPC;
872                 goto msix_entry_out;
873         }
874 
875 msix_entry_out:
876         mutex_unlock(&kvm->lock);
877 
878         return r;
879 }
880 #endif
881 
882 static int kvm_vm_ioctl_set_pci_irq_mask(struct kvm *kvm,
883                 struct kvm_assigned_pci_dev *assigned_dev)
884 {
885         int r = 0;
886         struct kvm_assigned_dev_kernel *match;
887 
888         mutex_lock(&kvm->lock);
889 
890         match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
891                                       assigned_dev->assigned_dev_id);
892         if (!match) {
893                 r = -ENODEV;
894                 goto out;
895         }
896 
897         spin_lock(&match->intx_mask_lock);
898 
899         match->flags &= ~KVM_DEV_ASSIGN_MASK_INTX;
900         match->flags |= assigned_dev->flags & KVM_DEV_ASSIGN_MASK_INTX;
901 
902         if (match->irq_requested_type & KVM_DEV_IRQ_GUEST_INTX) {
903                 if (assigned_dev->flags & KVM_DEV_ASSIGN_MASK_INTX) {
904                         kvm_set_irq(match->kvm, match->irq_source_id,
905                                     match->guest_irq, 0, false);
906                         /*
907                          * Masking at hardware-level is performed on demand,
908                          * i.e. when an IRQ actually arrives at the host.
909                          */
910                 } else if (!(assigned_dev->flags & KVM_DEV_ASSIGN_PCI_2_3)) {
911                         /*
912                          * Unmask the IRQ line if required. Unmasking at
913                          * device level will be performed by user space.
914                          */
915                         spin_lock_irq(&match->intx_lock);
916                         if (match->host_irq_disabled) {
917                                 enable_irq(match->host_irq);
918                                 match->host_irq_disabled = false;
919                         }
920                         spin_unlock_irq(&match->intx_lock);
921                 }
922         }
923 
924         spin_unlock(&match->intx_mask_lock);
925 
926 out:
927         mutex_unlock(&kvm->lock);
928         return r;
929 }
930 
931 long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl,
932                                   unsigned long arg)
933 {
934         void __user *argp = (void __user *)arg;
935         int r;
936 
937         switch (ioctl) {
938         case KVM_ASSIGN_PCI_DEVICE: {
939                 struct kvm_assigned_pci_dev assigned_dev;
940 
941                 r = -EFAULT;
942                 if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
943                         goto out;
944                 r = kvm_vm_ioctl_assign_device(kvm, &assigned_dev);
945                 if (r)
946                         goto out;
947                 break;
948         }
949         case KVM_ASSIGN_IRQ: {
950                 r = -EOPNOTSUPP;
951                 break;
952         }
953         case KVM_ASSIGN_DEV_IRQ: {
954                 struct kvm_assigned_irq assigned_irq;
955 
956                 r = -EFAULT;
957                 if (copy_from_user(&assigned_irq, argp, sizeof assigned_irq))
958                         goto out;
959                 r = kvm_vm_ioctl_assign_irq(kvm, &assigned_irq);
960                 if (r)
961                         goto out;
962                 break;
963         }
964         case KVM_DEASSIGN_DEV_IRQ: {
965                 struct kvm_assigned_irq assigned_irq;
966 
967                 r = -EFAULT;
968                 if (copy_from_user(&assigned_irq, argp, sizeof assigned_irq))
969                         goto out;
970                 r = kvm_vm_ioctl_deassign_dev_irq(kvm, &assigned_irq);
971                 if (r)
972                         goto out;
973                 break;
974         }
975         case KVM_DEASSIGN_PCI_DEVICE: {
976                 struct kvm_assigned_pci_dev assigned_dev;
977 
978                 r = -EFAULT;
979                 if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
980                         goto out;
981                 r = kvm_vm_ioctl_deassign_device(kvm, &assigned_dev);
982                 if (r)
983                         goto out;
984                 break;
985         }
986 #ifdef __KVM_HAVE_MSIX
987         case KVM_ASSIGN_SET_MSIX_NR: {
988                 struct kvm_assigned_msix_nr entry_nr;
989                 r = -EFAULT;
990                 if (copy_from_user(&entry_nr, argp, sizeof entry_nr))
991                         goto out;
992                 r = kvm_vm_ioctl_set_msix_nr(kvm, &entry_nr);
993                 if (r)
994                         goto out;
995                 break;
996         }
997         case KVM_ASSIGN_SET_MSIX_ENTRY: {
998                 struct kvm_assigned_msix_entry entry;
999                 r = -EFAULT;
1000                 if (copy_from_user(&entry, argp, sizeof entry))
1001                         goto out;
1002                 r = kvm_vm_ioctl_set_msix_entry(kvm, &entry);
1003                 if (r)
1004                         goto out;
1005                 break;
1006         }
1007 #endif
1008         case KVM_ASSIGN_SET_INTX_MASK: {
1009                 struct kvm_assigned_pci_dev assigned_dev;
1010 
1011                 r = -EFAULT;
1012                 if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
1013                         goto out;
1014                 r = kvm_vm_ioctl_set_pci_irq_mask(kvm, &assigned_dev);
1015                 break;
1016         }
1017         default:
1018                 r = -ENOTTY;
1019                 break;
1020         }
1021 out:
1022         return r;
1023 }
1024 

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