1 /*
2 * Copyright (C) 2012 Red Hat, Inc. All rights reserved.
3 * Author: Alex Williamson <alex.williamson@redhat.com>
4 *
5 * This program is free software; you can redistribute it and/or modify
6 * it under the terms of the GNU General Public License version 2 as
7 * published by the Free Software Foundation.
8 *
9 * Derived from original vfio:
10 * Copyright 2010 Cisco Systems, Inc. All rights reserved.
11 * Author: Tom Lyon, pugs@cisco.com
12 */
13
14 #include <linux/device.h>
15 #include <linux/eventfd.h>
16 #include <linux/file.h>
17 #include <linux/interrupt.h>
18 #include <linux/iommu.h>
19 #include <linux/module.h>
20 #include <linux/mutex.h>
21 #include <linux/notifier.h>
22 #include <linux/pci.h>
23 #include <linux/pm_runtime.h>
24 #include <linux/slab.h>
25 #include <linux/types.h>
26 #include <linux/uaccess.h>
27 #include <linux/vfio.h>
28
29 #include "vfio_pci_private.h"
30
31 #define DRIVER_VERSION "0.2"
32 #define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>"
33 #define DRIVER_DESC "VFIO PCI - User Level meta-driver"
34
35 static bool nointxmask;
36 module_param_named(nointxmask, nointxmask, bool, S_IRUGO | S_IWUSR);
37 MODULE_PARM_DESC(nointxmask,
38 "Disable support for PCI 2.3 style INTx masking. If this resolves problems for specific devices, report lspci -vvvxxx to linux-pci@vger.kernel.org so the device can be fixed automatically via the broken_intx_masking flag.");
39
40 static DEFINE_MUTEX(driver_lock);
41
42 static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev);
43
vfio_pci_enable(struct vfio_pci_device * vdev)44 static int vfio_pci_enable(struct vfio_pci_device *vdev)
45 {
46 struct pci_dev *pdev = vdev->pdev;
47 int ret;
48 u16 cmd;
49 u8 msix_pos;
50
51 /* Don't allow our initial saved state to include busmaster */
52 pci_clear_master(pdev);
53
54 ret = pci_enable_device(pdev);
55 if (ret)
56 return ret;
57
58 vdev->reset_works = (pci_reset_function(pdev) == 0);
59 pci_save_state(pdev);
60 vdev->pci_saved_state = pci_store_saved_state(pdev);
61 if (!vdev->pci_saved_state)
62 pr_debug("%s: Couldn't store %s saved state\n",
63 __func__, dev_name(&pdev->dev));
64
65 ret = vfio_config_init(vdev);
66 if (ret) {
67 kfree(vdev->pci_saved_state);
68 vdev->pci_saved_state = NULL;
69 pci_disable_device(pdev);
70 return ret;
71 }
72
73 if (likely(!nointxmask))
74 vdev->pci_2_3 = pci_intx_mask_supported(pdev);
75
76 pci_read_config_word(pdev, PCI_COMMAND, &cmd);
77 if (vdev->pci_2_3 && (cmd & PCI_COMMAND_INTX_DISABLE)) {
78 cmd &= ~PCI_COMMAND_INTX_DISABLE;
79 pci_write_config_word(pdev, PCI_COMMAND, cmd);
80 }
81
82 msix_pos = pdev->msix_cap;
83 if (msix_pos) {
84 u16 flags;
85 u32 table;
86
87 pci_read_config_word(pdev, msix_pos + PCI_MSIX_FLAGS, &flags);
88 pci_read_config_dword(pdev, msix_pos + PCI_MSIX_TABLE, &table);
89
90 vdev->msix_bar = table & PCI_MSIX_TABLE_BIR;
91 vdev->msix_offset = table & PCI_MSIX_TABLE_OFFSET;
92 vdev->msix_size = ((flags & PCI_MSIX_FLAGS_QSIZE) + 1) * 16;
93 } else
94 vdev->msix_bar = 0xFF;
95
96 #ifdef CONFIG_VFIO_PCI_VGA
97 if ((pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA)
98 vdev->has_vga = true;
99 #endif
100
101 return 0;
102 }
103
vfio_pci_disable(struct vfio_pci_device * vdev)104 static void vfio_pci_disable(struct vfio_pci_device *vdev)
105 {
106 struct pci_dev *pdev = vdev->pdev;
107 int bar;
108
109 /* Stop the device from further DMA */
110 pci_clear_master(pdev);
111
112 vfio_pci_set_irqs_ioctl(vdev, VFIO_IRQ_SET_DATA_NONE |
113 VFIO_IRQ_SET_ACTION_TRIGGER,
114 vdev->irq_type, 0, 0, NULL);
115
116 vdev->virq_disabled = false;
117
118 vfio_config_free(vdev);
119
120 for (bar = PCI_STD_RESOURCES; bar <= PCI_STD_RESOURCE_END; bar++) {
121 if (!vdev->barmap[bar])
122 continue;
123 pci_iounmap(pdev, vdev->barmap[bar]);
124 pci_release_selected_regions(pdev, 1 << bar);
125 vdev->barmap[bar] = NULL;
126 }
127
128 vdev->needs_reset = true;
129
130 /*
131 * If we have saved state, restore it. If we can reset the device,
132 * even better. Resetting with current state seems better than
133 * nothing, but saving and restoring current state without reset
134 * is just busy work.
135 */
136 if (pci_load_and_free_saved_state(pdev, &vdev->pci_saved_state)) {
137 pr_info("%s: Couldn't reload %s saved state\n",
138 __func__, dev_name(&pdev->dev));
139
140 if (!vdev->reset_works)
141 goto out;
142
143 pci_save_state(pdev);
144 }
145
146 /*
147 * Disable INTx and MSI, presumably to avoid spurious interrupts
148 * during reset. Stolen from pci_reset_function()
149 */
150 pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
151
152 /*
153 * Try to reset the device. The success of this is dependent on
154 * being able to lock the device, which is not always possible.
155 */
156 if (vdev->reset_works) {
157 int ret = pci_try_reset_function(pdev);
158 if (ret)
159 pr_warn("%s: Failed to reset device %s (%d)\n",
160 __func__, dev_name(&pdev->dev), ret);
161 else
162 vdev->needs_reset = false;
163 }
164
165 pci_restore_state(pdev);
166 out:
167 pci_disable_device(pdev);
168
169 vfio_pci_try_bus_reset(vdev);
170 }
171
vfio_pci_release(void * device_data)172 static void vfio_pci_release(void *device_data)
173 {
174 struct vfio_pci_device *vdev = device_data;
175
176 mutex_lock(&driver_lock);
177
178 if (!(--vdev->refcnt)) {
179 vfio_spapr_pci_eeh_release(vdev->pdev);
180 vfio_pci_disable(vdev);
181 }
182
183 mutex_unlock(&driver_lock);
184
185 module_put(THIS_MODULE);
186 }
187
vfio_pci_open(void * device_data)188 static int vfio_pci_open(void *device_data)
189 {
190 struct vfio_pci_device *vdev = device_data;
191 int ret = 0;
192
193 if (!try_module_get(THIS_MODULE))
194 return -ENODEV;
195
196 mutex_lock(&driver_lock);
197
198 if (!vdev->refcnt) {
199 ret = vfio_pci_enable(vdev);
200 if (ret)
201 goto error;
202
203 vfio_spapr_pci_eeh_open(vdev->pdev);
204 }
205 vdev->refcnt++;
206 error:
207 mutex_unlock(&driver_lock);
208 if (ret)
209 module_put(THIS_MODULE);
210 return ret;
211 }
212
vfio_pci_get_irq_count(struct vfio_pci_device * vdev,int irq_type)213 static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type)
214 {
215 if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) {
216 u8 pin;
217 pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN, &pin);
218 if (pin)
219 return 1;
220
221 } else if (irq_type == VFIO_PCI_MSI_IRQ_INDEX) {
222 u8 pos;
223 u16 flags;
224
225 pos = vdev->pdev->msi_cap;
226 if (pos) {
227 pci_read_config_word(vdev->pdev,
228 pos + PCI_MSI_FLAGS, &flags);
229 return 1 << ((flags & PCI_MSI_FLAGS_QMASK) >> 1);
230 }
231 } else if (irq_type == VFIO_PCI_MSIX_IRQ_INDEX) {
232 u8 pos;
233 u16 flags;
234
235 pos = vdev->pdev->msix_cap;
236 if (pos) {
237 pci_read_config_word(vdev->pdev,
238 pos + PCI_MSIX_FLAGS, &flags);
239
240 return (flags & PCI_MSIX_FLAGS_QSIZE) + 1;
241 }
242 } else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX)
243 if (pci_is_pcie(vdev->pdev))
244 return 1;
245
246 return 0;
247 }
248
vfio_pci_count_devs(struct pci_dev * pdev,void * data)249 static int vfio_pci_count_devs(struct pci_dev *pdev, void *data)
250 {
251 (*(int *)data)++;
252 return 0;
253 }
254
255 struct vfio_pci_fill_info {
256 int max;
257 int cur;
258 struct vfio_pci_dependent_device *devices;
259 };
260
vfio_pci_fill_devs(struct pci_dev * pdev,void * data)261 static int vfio_pci_fill_devs(struct pci_dev *pdev, void *data)
262 {
263 struct vfio_pci_fill_info *fill = data;
264 struct iommu_group *iommu_group;
265
266 if (fill->cur == fill->max)
267 return -EAGAIN; /* Something changed, try again */
268
269 iommu_group = iommu_group_get(&pdev->dev);
270 if (!iommu_group)
271 return -EPERM; /* Cannot reset non-isolated devices */
272
273 fill->devices[fill->cur].group_id = iommu_group_id(iommu_group);
274 fill->devices[fill->cur].segment = pci_domain_nr(pdev->bus);
275 fill->devices[fill->cur].bus = pdev->bus->number;
276 fill->devices[fill->cur].devfn = pdev->devfn;
277 fill->cur++;
278 iommu_group_put(iommu_group);
279 return 0;
280 }
281
282 struct vfio_pci_group_entry {
283 struct vfio_group *group;
284 int id;
285 };
286
287 struct vfio_pci_group_info {
288 int count;
289 struct vfio_pci_group_entry *groups;
290 };
291
vfio_pci_validate_devs(struct pci_dev * pdev,void * data)292 static int vfio_pci_validate_devs(struct pci_dev *pdev, void *data)
293 {
294 struct vfio_pci_group_info *info = data;
295 struct iommu_group *group;
296 int id, i;
297
298 group = iommu_group_get(&pdev->dev);
299 if (!group)
300 return -EPERM;
301
302 id = iommu_group_id(group);
303
304 for (i = 0; i < info->count; i++)
305 if (info->groups[i].id == id)
306 break;
307
308 iommu_group_put(group);
309
310 return (i == info->count) ? -EINVAL : 0;
311 }
312
vfio_pci_dev_below_slot(struct pci_dev * pdev,struct pci_slot * slot)313 static bool vfio_pci_dev_below_slot(struct pci_dev *pdev, struct pci_slot *slot)
314 {
315 for (; pdev; pdev = pdev->bus->self)
316 if (pdev->bus == slot->bus)
317 return (pdev->slot == slot);
318 return false;
319 }
320
321 struct vfio_pci_walk_info {
322 int (*fn)(struct pci_dev *, void *data);
323 void *data;
324 struct pci_dev *pdev;
325 bool slot;
326 int ret;
327 };
328
vfio_pci_walk_wrapper(struct pci_dev * pdev,void * data)329 static int vfio_pci_walk_wrapper(struct pci_dev *pdev, void *data)
330 {
331 struct vfio_pci_walk_info *walk = data;
332
333 if (!walk->slot || vfio_pci_dev_below_slot(pdev, walk->pdev->slot))
334 walk->ret = walk->fn(pdev, walk->data);
335
336 return walk->ret;
337 }
338
vfio_pci_for_each_slot_or_bus(struct pci_dev * pdev,int (* fn)(struct pci_dev *,void * data),void * data,bool slot)339 static int vfio_pci_for_each_slot_or_bus(struct pci_dev *pdev,
340 int (*fn)(struct pci_dev *,
341 void *data), void *data,
342 bool slot)
343 {
344 struct vfio_pci_walk_info walk = {
345 .fn = fn, .data = data, .pdev = pdev, .slot = slot, .ret = 0,
346 };
347
348 pci_walk_bus(pdev->bus, vfio_pci_walk_wrapper, &walk);
349
350 return walk.ret;
351 }
352
vfio_pci_ioctl(void * device_data,unsigned int cmd,unsigned long arg)353 static long vfio_pci_ioctl(void *device_data,
354 unsigned int cmd, unsigned long arg)
355 {
356 struct vfio_pci_device *vdev = device_data;
357 unsigned long minsz;
358
359 if (cmd == VFIO_DEVICE_GET_INFO) {
360 struct vfio_device_info info;
361
362 minsz = offsetofend(struct vfio_device_info, num_irqs);
363
364 if (copy_from_user(&info, (void __user *)arg, minsz))
365 return -EFAULT;
366
367 if (info.argsz < minsz)
368 return -EINVAL;
369
370 info.flags = VFIO_DEVICE_FLAGS_PCI;
371
372 if (vdev->reset_works)
373 info.flags |= VFIO_DEVICE_FLAGS_RESET;
374
375 info.num_regions = VFIO_PCI_NUM_REGIONS;
376 info.num_irqs = VFIO_PCI_NUM_IRQS;
377
378 return copy_to_user((void __user *)arg, &info, minsz) ?
379 -EFAULT : 0;
380
381 } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
382 struct pci_dev *pdev = vdev->pdev;
383 struct vfio_region_info info;
384
385 minsz = offsetofend(struct vfio_region_info, offset);
386
387 if (copy_from_user(&info, (void __user *)arg, minsz))
388 return -EFAULT;
389
390 if (info.argsz < minsz)
391 return -EINVAL;
392
393 switch (info.index) {
394 case VFIO_PCI_CONFIG_REGION_INDEX:
395 info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
396 info.size = pdev->cfg_size;
397 info.flags = VFIO_REGION_INFO_FLAG_READ |
398 VFIO_REGION_INFO_FLAG_WRITE;
399 break;
400 case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
401 info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
402 info.size = pci_resource_len(pdev, info.index);
403 if (!info.size) {
404 info.flags = 0;
405 break;
406 }
407
408 info.flags = VFIO_REGION_INFO_FLAG_READ |
409 VFIO_REGION_INFO_FLAG_WRITE;
410 if (pci_resource_flags(pdev, info.index) &
411 IORESOURCE_MEM && info.size >= PAGE_SIZE)
412 info.flags |= VFIO_REGION_INFO_FLAG_MMAP;
413 break;
414 case VFIO_PCI_ROM_REGION_INDEX:
415 {
416 void __iomem *io;
417 size_t size;
418
419 info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
420 info.flags = 0;
421
422 /* Report the BAR size, not the ROM size */
423 info.size = pci_resource_len(pdev, info.index);
424 if (!info.size)
425 break;
426
427 /* Is it really there? */
428 io = pci_map_rom(pdev, &size);
429 if (!io || !size) {
430 info.size = 0;
431 break;
432 }
433 pci_unmap_rom(pdev, io);
434
435 info.flags = VFIO_REGION_INFO_FLAG_READ;
436 break;
437 }
438 case VFIO_PCI_VGA_REGION_INDEX:
439 if (!vdev->has_vga)
440 return -EINVAL;
441
442 info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
443 info.size = 0xc0000;
444 info.flags = VFIO_REGION_INFO_FLAG_READ |
445 VFIO_REGION_INFO_FLAG_WRITE;
446
447 break;
448 default:
449 return -EINVAL;
450 }
451
452 return copy_to_user((void __user *)arg, &info, minsz) ?
453 -EFAULT : 0;
454
455 } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
456 struct vfio_irq_info info;
457
458 minsz = offsetofend(struct vfio_irq_info, count);
459
460 if (copy_from_user(&info, (void __user *)arg, minsz))
461 return -EFAULT;
462
463 if (info.argsz < minsz || info.index >= VFIO_PCI_NUM_IRQS)
464 return -EINVAL;
465
466 switch (info.index) {
467 case VFIO_PCI_INTX_IRQ_INDEX ... VFIO_PCI_MSIX_IRQ_INDEX:
468 break;
469 case VFIO_PCI_ERR_IRQ_INDEX:
470 if (pci_is_pcie(vdev->pdev))
471 break;
472 /* pass thru to return error */
473 default:
474 return -EINVAL;
475 }
476
477 info.flags = VFIO_IRQ_INFO_EVENTFD;
478
479 info.count = vfio_pci_get_irq_count(vdev, info.index);
480
481 if (info.index == VFIO_PCI_INTX_IRQ_INDEX)
482 info.flags |= (VFIO_IRQ_INFO_MASKABLE |
483 VFIO_IRQ_INFO_AUTOMASKED);
484 else
485 info.flags |= VFIO_IRQ_INFO_NORESIZE;
486
487 return copy_to_user((void __user *)arg, &info, minsz) ?
488 -EFAULT : 0;
489
490 } else if (cmd == VFIO_DEVICE_SET_IRQS) {
491 struct vfio_irq_set hdr;
492 size_t size;
493 u8 *data = NULL;
494 int max, ret = 0;
495
496 minsz = offsetofend(struct vfio_irq_set, count);
497
498 if (copy_from_user(&hdr, (void __user *)arg, minsz))
499 return -EFAULT;
500
501 if (hdr.argsz < minsz || hdr.index >= VFIO_PCI_NUM_IRQS ||
502 hdr.count >= (U32_MAX - hdr.start) ||
503 hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
504 VFIO_IRQ_SET_ACTION_TYPE_MASK))
505 return -EINVAL;
506
507 max = vfio_pci_get_irq_count(vdev, hdr.index);
508 if (hdr.start >= max || hdr.start + hdr.count > max)
509 return -EINVAL;
510
511 switch (hdr.flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
512 case VFIO_IRQ_SET_DATA_NONE:
513 size = 0;
514 break;
515 case VFIO_IRQ_SET_DATA_BOOL:
516 size = sizeof(uint8_t);
517 break;
518 case VFIO_IRQ_SET_DATA_EVENTFD:
519 size = sizeof(int32_t);
520 break;
521 default:
522 return -EINVAL;
523 }
524
525 if (size) {
526 if (hdr.argsz - minsz < hdr.count * size)
527 return -EINVAL;
528
529 data = memdup_user((void __user *)(arg + minsz),
530 hdr.count * size);
531 if (IS_ERR(data))
532 return PTR_ERR(data);
533 }
534
535 mutex_lock(&vdev->igate);
536
537 ret = vfio_pci_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
538 hdr.start, hdr.count, data);
539
540 mutex_unlock(&vdev->igate);
541 kfree(data);
542
543 return ret;
544
545 } else if (cmd == VFIO_DEVICE_RESET) {
546 return vdev->reset_works ?
547 pci_try_reset_function(vdev->pdev) : -EINVAL;
548
549 } else if (cmd == VFIO_DEVICE_GET_PCI_HOT_RESET_INFO) {
550 struct vfio_pci_hot_reset_info hdr;
551 struct vfio_pci_fill_info fill = { 0 };
552 struct vfio_pci_dependent_device *devices = NULL;
553 bool slot = false;
554 int ret = 0;
555
556 minsz = offsetofend(struct vfio_pci_hot_reset_info, count);
557
558 if (copy_from_user(&hdr, (void __user *)arg, minsz))
559 return -EFAULT;
560
561 if (hdr.argsz < minsz)
562 return -EINVAL;
563
564 hdr.flags = 0;
565
566 /* Can we do a slot or bus reset or neither? */
567 if (!pci_probe_reset_slot(vdev->pdev->slot))
568 slot = true;
569 else if (pci_probe_reset_bus(vdev->pdev->bus))
570 return -ENODEV;
571
572 /* How many devices are affected? */
573 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
574 vfio_pci_count_devs,
575 &fill.max, slot);
576 if (ret)
577 return ret;
578
579 WARN_ON(!fill.max); /* Should always be at least one */
580
581 /*
582 * If there's enough space, fill it now, otherwise return
583 * -ENOSPC and the number of devices affected.
584 */
585 if (hdr.argsz < sizeof(hdr) + (fill.max * sizeof(*devices))) {
586 ret = -ENOSPC;
587 hdr.count = fill.max;
588 goto reset_info_exit;
589 }
590
591 devices = kcalloc(fill.max, sizeof(*devices), GFP_KERNEL);
592 if (!devices)
593 return -ENOMEM;
594
595 fill.devices = devices;
596
597 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
598 vfio_pci_fill_devs,
599 &fill, slot);
600
601 /*
602 * If a device was removed between counting and filling,
603 * we may come up short of fill.max. If a device was
604 * added, we'll have a return of -EAGAIN above.
605 */
606 if (!ret)
607 hdr.count = fill.cur;
608
609 reset_info_exit:
610 if (copy_to_user((void __user *)arg, &hdr, minsz))
611 ret = -EFAULT;
612
613 if (!ret) {
614 if (copy_to_user((void __user *)(arg + minsz), devices,
615 hdr.count * sizeof(*devices)))
616 ret = -EFAULT;
617 }
618
619 kfree(devices);
620 return ret;
621
622 } else if (cmd == VFIO_DEVICE_PCI_HOT_RESET) {
623 struct vfio_pci_hot_reset hdr;
624 int32_t *group_fds;
625 struct vfio_pci_group_entry *groups;
626 struct vfio_pci_group_info info;
627 bool slot = false;
628 int i, count = 0, ret = 0;
629
630 minsz = offsetofend(struct vfio_pci_hot_reset, count);
631
632 if (copy_from_user(&hdr, (void __user *)arg, minsz))
633 return -EFAULT;
634
635 if (hdr.argsz < minsz || hdr.flags)
636 return -EINVAL;
637
638 /* Can we do a slot or bus reset or neither? */
639 if (!pci_probe_reset_slot(vdev->pdev->slot))
640 slot = true;
641 else if (pci_probe_reset_bus(vdev->pdev->bus))
642 return -ENODEV;
643
644 /*
645 * We can't let userspace give us an arbitrarily large
646 * buffer to copy, so verify how many we think there
647 * could be. Note groups can have multiple devices so
648 * one group per device is the max.
649 */
650 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
651 vfio_pci_count_devs,
652 &count, slot);
653 if (ret)
654 return ret;
655
656 /* Somewhere between 1 and count is OK */
657 if (!hdr.count || hdr.count > count)
658 return -EINVAL;
659
660 group_fds = kcalloc(hdr.count, sizeof(*group_fds), GFP_KERNEL);
661 groups = kcalloc(hdr.count, sizeof(*groups), GFP_KERNEL);
662 if (!group_fds || !groups) {
663 kfree(group_fds);
664 kfree(groups);
665 return -ENOMEM;
666 }
667
668 if (copy_from_user(group_fds, (void __user *)(arg + minsz),
669 hdr.count * sizeof(*group_fds))) {
670 kfree(group_fds);
671 kfree(groups);
672 return -EFAULT;
673 }
674
675 /*
676 * For each group_fd, get the group through the vfio external
677 * user interface and store the group and iommu ID. This
678 * ensures the group is held across the reset.
679 */
680 for (i = 0; i < hdr.count; i++) {
681 struct vfio_group *group;
682 struct fd f = fdget(group_fds[i]);
683 if (!f.file) {
684 ret = -EBADF;
685 break;
686 }
687
688 group = vfio_group_get_external_user(f.file);
689 fdput(f);
690 if (IS_ERR(group)) {
691 ret = PTR_ERR(group);
692 break;
693 }
694
695 groups[i].group = group;
696 groups[i].id = vfio_external_user_iommu_id(group);
697 }
698
699 kfree(group_fds);
700
701 /* release reference to groups on error */
702 if (ret)
703 goto hot_reset_release;
704
705 info.count = hdr.count;
706 info.groups = groups;
707
708 /*
709 * Test whether all the affected devices are contained
710 * by the set of groups provided by the user.
711 */
712 ret = vfio_pci_for_each_slot_or_bus(vdev->pdev,
713 vfio_pci_validate_devs,
714 &info, slot);
715 if (!ret)
716 /* User has access, do the reset */
717 ret = slot ? pci_try_reset_slot(vdev->pdev->slot) :
718 pci_try_reset_bus(vdev->pdev->bus);
719
720 hot_reset_release:
721 for (i--; i >= 0; i--)
722 vfio_group_put_external_user(groups[i].group);
723
724 kfree(groups);
725 return ret;
726 }
727
728 return -ENOTTY;
729 }
730
vfio_pci_rw(void * device_data,char __user * buf,size_t count,loff_t * ppos,bool iswrite)731 static ssize_t vfio_pci_rw(void *device_data, char __user *buf,
732 size_t count, loff_t *ppos, bool iswrite)
733 {
734 unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
735 struct vfio_pci_device *vdev = device_data;
736
737 if (index >= VFIO_PCI_NUM_REGIONS)
738 return -EINVAL;
739
740 switch (index) {
741 case VFIO_PCI_CONFIG_REGION_INDEX:
742 return vfio_pci_config_rw(vdev, buf, count, ppos, iswrite);
743
744 case VFIO_PCI_ROM_REGION_INDEX:
745 if (iswrite)
746 return -EINVAL;
747 return vfio_pci_bar_rw(vdev, buf, count, ppos, false);
748
749 case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
750 return vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite);
751
752 case VFIO_PCI_VGA_REGION_INDEX:
753 return vfio_pci_vga_rw(vdev, buf, count, ppos, iswrite);
754 }
755
756 return -EINVAL;
757 }
758
vfio_pci_read(void * device_data,char __user * buf,size_t count,loff_t * ppos)759 static ssize_t vfio_pci_read(void *device_data, char __user *buf,
760 size_t count, loff_t *ppos)
761 {
762 if (!count)
763 return 0;
764
765 return vfio_pci_rw(device_data, buf, count, ppos, false);
766 }
767
vfio_pci_write(void * device_data,const char __user * buf,size_t count,loff_t * ppos)768 static ssize_t vfio_pci_write(void *device_data, const char __user *buf,
769 size_t count, loff_t *ppos)
770 {
771 if (!count)
772 return 0;
773
774 return vfio_pci_rw(device_data, (char __user *)buf, count, ppos, true);
775 }
776
vfio_pci_mmap(void * device_data,struct vm_area_struct * vma)777 static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma)
778 {
779 struct vfio_pci_device *vdev = device_data;
780 struct pci_dev *pdev = vdev->pdev;
781 unsigned int index;
782 u64 phys_len, req_len, pgoff, req_start;
783 int ret;
784
785 index = vma->vm_pgoff >> (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT);
786
787 if (vma->vm_end < vma->vm_start)
788 return -EINVAL;
789 if ((vma->vm_flags & VM_SHARED) == 0)
790 return -EINVAL;
791 if (index >= VFIO_PCI_ROM_REGION_INDEX)
792 return -EINVAL;
793 if (!(pci_resource_flags(pdev, index) & IORESOURCE_MEM))
794 return -EINVAL;
795
796 phys_len = pci_resource_len(pdev, index);
797 req_len = vma->vm_end - vma->vm_start;
798 pgoff = vma->vm_pgoff &
799 ((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
800 req_start = pgoff << PAGE_SHIFT;
801
802 if (phys_len < PAGE_SIZE || req_start + req_len > phys_len)
803 return -EINVAL;
804
805 if (index == vdev->msix_bar) {
806 /*
807 * Disallow mmaps overlapping the MSI-X table; users don't
808 * get to touch this directly. We could find somewhere
809 * else to map the overlap, but page granularity is only
810 * a recommendation, not a requirement, so the user needs
811 * to know which bits are real. Requiring them to mmap
812 * around the table makes that clear.
813 */
814
815 /* If neither entirely above nor below, then it overlaps */
816 if (!(req_start >= vdev->msix_offset + vdev->msix_size ||
817 req_start + req_len <= vdev->msix_offset))
818 return -EINVAL;
819 }
820
821 /*
822 * Even though we don't make use of the barmap for the mmap,
823 * we need to request the region and the barmap tracks that.
824 */
825 if (!vdev->barmap[index]) {
826 ret = pci_request_selected_regions(pdev,
827 1 << index, "vfio-pci");
828 if (ret)
829 return ret;
830
831 vdev->barmap[index] = pci_iomap(pdev, index, 0);
832 }
833
834 vma->vm_private_data = vdev;
835 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
836 vma->vm_pgoff = (pci_resource_start(pdev, index) >> PAGE_SHIFT) + pgoff;
837
838 return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
839 req_len, vma->vm_page_prot);
840 }
841
842 static const struct vfio_device_ops vfio_pci_ops = {
843 .name = "vfio-pci",
844 .open = vfio_pci_open,
845 .release = vfio_pci_release,
846 .ioctl = vfio_pci_ioctl,
847 .read = vfio_pci_read,
848 .write = vfio_pci_write,
849 .mmap = vfio_pci_mmap,
850 };
851
vfio_pci_probe(struct pci_dev * pdev,const struct pci_device_id * id)852 static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
853 {
854 struct vfio_pci_device *vdev;
855 struct iommu_group *group;
856 int ret;
857
858 if (pdev->hdr_type != PCI_HEADER_TYPE_NORMAL)
859 return -EINVAL;
860
861 group = iommu_group_get(&pdev->dev);
862 if (!group)
863 return -EINVAL;
864
865 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
866 if (!vdev) {
867 iommu_group_put(group);
868 return -ENOMEM;
869 }
870
871 vdev->pdev = pdev;
872 vdev->irq_type = VFIO_PCI_NUM_IRQS;
873 mutex_init(&vdev->igate);
874 spin_lock_init(&vdev->irqlock);
875
876 ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev);
877 if (ret) {
878 iommu_group_put(group);
879 kfree(vdev);
880 }
881
882 return ret;
883 }
884
vfio_pci_remove(struct pci_dev * pdev)885 static void vfio_pci_remove(struct pci_dev *pdev)
886 {
887 struct vfio_pci_device *vdev;
888
889 vdev = vfio_del_group_dev(&pdev->dev);
890 if (vdev) {
891 iommu_group_put(pdev->dev.iommu_group);
892 kfree(vdev);
893 }
894 }
895
vfio_pci_aer_err_detected(struct pci_dev * pdev,pci_channel_state_t state)896 static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
897 pci_channel_state_t state)
898 {
899 struct vfio_pci_device *vdev;
900 struct vfio_device *device;
901
902 device = vfio_device_get_from_dev(&pdev->dev);
903 if (device == NULL)
904 return PCI_ERS_RESULT_DISCONNECT;
905
906 vdev = vfio_device_data(device);
907 if (vdev == NULL) {
908 vfio_device_put(device);
909 return PCI_ERS_RESULT_DISCONNECT;
910 }
911
912 mutex_lock(&vdev->igate);
913
914 if (vdev->err_trigger)
915 eventfd_signal(vdev->err_trigger, 1);
916
917 mutex_unlock(&vdev->igate);
918
919 vfio_device_put(device);
920
921 return PCI_ERS_RESULT_CAN_RECOVER;
922 }
923
924 static struct pci_error_handlers vfio_err_handlers = {
925 .error_detected = vfio_pci_aer_err_detected,
926 };
927
928 static struct pci_driver vfio_pci_driver = {
929 .name = "vfio-pci",
930 .id_table = NULL, /* only dynamic ids */
931 .probe = vfio_pci_probe,
932 .remove = vfio_pci_remove,
933 .err_handler = &vfio_err_handlers,
934 };
935
936 struct vfio_devices {
937 struct vfio_device **devices;
938 int cur_index;
939 int max_index;
940 };
941
vfio_pci_get_devs(struct pci_dev * pdev,void * data)942 static int vfio_pci_get_devs(struct pci_dev *pdev, void *data)
943 {
944 struct vfio_devices *devs = data;
945 struct pci_driver *pci_drv = ACCESS_ONCE(pdev->driver);
946
947 if (pci_drv != &vfio_pci_driver)
948 return -EBUSY;
949
950 if (devs->cur_index == devs->max_index)
951 return -ENOSPC;
952
953 devs->devices[devs->cur_index] = vfio_device_get_from_dev(&pdev->dev);
954 if (!devs->devices[devs->cur_index])
955 return -EINVAL;
956
957 devs->cur_index++;
958 return 0;
959 }
960
961 /*
962 * Attempt to do a bus/slot reset if there are devices affected by a reset for
963 * this device that are needs_reset and all of the affected devices are unused
964 * (!refcnt). Callers are required to hold driver_lock when calling this to
965 * prevent device opens and concurrent bus reset attempts. We prevent device
966 * unbinds by acquiring and holding a reference to the vfio_device.
967 *
968 * NB: vfio-core considers a group to be viable even if some devices are
969 * bound to drivers like pci-stub or pcieport. Here we require all devices
970 * to be bound to vfio_pci since that's the only way we can be sure they
971 * stay put.
972 */
vfio_pci_try_bus_reset(struct vfio_pci_device * vdev)973 static void vfio_pci_try_bus_reset(struct vfio_pci_device *vdev)
974 {
975 struct vfio_devices devs = { .cur_index = 0 };
976 int i = 0, ret = -EINVAL;
977 bool needs_reset = false, slot = false;
978 struct vfio_pci_device *tmp;
979
980 if (!pci_probe_reset_slot(vdev->pdev->slot))
981 slot = true;
982 else if (pci_probe_reset_bus(vdev->pdev->bus))
983 return;
984
985 if (vfio_pci_for_each_slot_or_bus(vdev->pdev, vfio_pci_count_devs,
986 &i, slot) || !i)
987 return;
988
989 devs.max_index = i;
990 devs.devices = kcalloc(i, sizeof(struct vfio_device *), GFP_KERNEL);
991 if (!devs.devices)
992 return;
993
994 if (vfio_pci_for_each_slot_or_bus(vdev->pdev,
995 vfio_pci_get_devs, &devs, slot))
996 goto put_devs;
997
998 for (i = 0; i < devs.cur_index; i++) {
999 tmp = vfio_device_data(devs.devices[i]);
1000 if (tmp->needs_reset)
1001 needs_reset = true;
1002 if (tmp->refcnt)
1003 goto put_devs;
1004 }
1005
1006 if (needs_reset)
1007 ret = slot ? pci_try_reset_slot(vdev->pdev->slot) :
1008 pci_try_reset_bus(vdev->pdev->bus);
1009
1010 put_devs:
1011 for (i = 0; i < devs.cur_index; i++) {
1012 if (!ret) {
1013 tmp = vfio_device_data(devs.devices[i]);
1014 tmp->needs_reset = false;
1015 }
1016 vfio_device_put(devs.devices[i]);
1017 }
1018
1019 kfree(devs.devices);
1020 }
1021
vfio_pci_cleanup(void)1022 static void __exit vfio_pci_cleanup(void)
1023 {
1024 pci_unregister_driver(&vfio_pci_driver);
1025 vfio_pci_virqfd_exit();
1026 vfio_pci_uninit_perm_bits();
1027 }
1028
vfio_pci_init(void)1029 static int __init vfio_pci_init(void)
1030 {
1031 int ret;
1032
1033 /* Allocate shared config space permision data used by all devices */
1034 ret = vfio_pci_init_perm_bits();
1035 if (ret)
1036 return ret;
1037
1038 /* Start the virqfd cleanup handler */
1039 ret = vfio_pci_virqfd_init();
1040 if (ret)
1041 goto out_virqfd;
1042
1043 /* Register and scan for devices */
1044 ret = pci_register_driver(&vfio_pci_driver);
1045 if (ret)
1046 goto out_driver;
1047
1048 return 0;
1049
1050 out_driver:
1051 vfio_pci_virqfd_exit();
1052 out_virqfd:
1053 vfio_pci_uninit_perm_bits();
1054 return ret;
1055 }
1056
1057 module_init(vfio_pci_init);
1058 module_exit(vfio_pci_cleanup);
1059
1060 MODULE_VERSION(DRIVER_VERSION);
1061 MODULE_LICENSE("GPL v2");
1062 MODULE_AUTHOR(DRIVER_AUTHOR);
1063 MODULE_DESCRIPTION(DRIVER_DESC);
1064