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14#include <linux/device.h>
15#include <linux/eventfd.h>
16#include <linux/interrupt.h>
17#include <linux/iommu.h>
18#include <linux/module.h>
19#include <linux/mutex.h>
20#include <linux/notifier.h>
21#include <linux/pci.h>
22#include <linux/pm_runtime.h>
23#include <linux/slab.h>
24#include <linux/types.h>
25#include <linux/uaccess.h>
26#include <linux/vfio.h>
27
28#include "vfio_pci_private.h"
29
30#define DRIVER_VERSION "0.2"
31#define DRIVER_AUTHOR "Alex Williamson <alex.williamson@redhat.com>"
32#define DRIVER_DESC "VFIO PCI - User Level meta-driver"
33
34static bool nointxmask;
35module_param_named(nointxmask, nointxmask, bool, S_IRUGO | S_IWUSR);
36MODULE_PARM_DESC(nointxmask,
37 "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.");
38
39static int vfio_pci_enable(struct vfio_pci_device *vdev)
40{
41 struct pci_dev *pdev = vdev->pdev;
42 int ret;
43 u16 cmd;
44 u8 msix_pos;
45
46 ret = pci_enable_device(pdev);
47 if (ret)
48 return ret;
49
50 vdev->reset_works = (pci_reset_function(pdev) == 0);
51 pci_save_state(pdev);
52 vdev->pci_saved_state = pci_store_saved_state(pdev);
53 if (!vdev->pci_saved_state)
54 pr_debug("%s: Couldn't store %s saved state\n",
55 __func__, dev_name(&pdev->dev));
56
57 ret = vfio_config_init(vdev);
58 if (ret) {
59 pci_load_and_free_saved_state(pdev, &vdev->pci_saved_state);
60 pci_disable_device(pdev);
61 return ret;
62 }
63
64 if (likely(!nointxmask))
65 vdev->pci_2_3 = pci_intx_mask_supported(pdev);
66
67 pci_read_config_word(pdev, PCI_COMMAND, &cmd);
68 if (vdev->pci_2_3 && (cmd & PCI_COMMAND_INTX_DISABLE)) {
69 cmd &= ~PCI_COMMAND_INTX_DISABLE;
70 pci_write_config_word(pdev, PCI_COMMAND, cmd);
71 }
72
73 msix_pos = pdev->msix_cap;
74 if (msix_pos) {
75 u16 flags;
76 u32 table;
77
78 pci_read_config_word(pdev, msix_pos + PCI_MSIX_FLAGS, &flags);
79 pci_read_config_dword(pdev, msix_pos + PCI_MSIX_TABLE, &table);
80
81 vdev->msix_bar = table & PCI_MSIX_TABLE_BIR;
82 vdev->msix_offset = table & PCI_MSIX_TABLE_OFFSET;
83 vdev->msix_size = ((flags & PCI_MSIX_FLAGS_QSIZE) + 1) * 16;
84 } else
85 vdev->msix_bar = 0xFF;
86
87#ifdef CONFIG_VFIO_PCI_VGA
88 if ((pdev->class >> 8) == PCI_CLASS_DISPLAY_VGA)
89 vdev->has_vga = true;
90#endif
91
92 return 0;
93}
94
95static void vfio_pci_disable(struct vfio_pci_device *vdev)
96{
97 struct pci_dev *pdev = vdev->pdev;
98 int bar;
99
100 pci_disable_device(pdev);
101
102 vfio_pci_set_irqs_ioctl(vdev, VFIO_IRQ_SET_DATA_NONE |
103 VFIO_IRQ_SET_ACTION_TRIGGER,
104 vdev->irq_type, 0, 0, NULL);
105
106 vdev->virq_disabled = false;
107
108 vfio_config_free(vdev);
109
110 for (bar = PCI_STD_RESOURCES; bar <= PCI_STD_RESOURCE_END; bar++) {
111 if (!vdev->barmap[bar])
112 continue;
113 pci_iounmap(pdev, vdev->barmap[bar]);
114 pci_release_selected_regions(pdev, 1 << bar);
115 vdev->barmap[bar] = NULL;
116 }
117
118
119
120
121
122
123
124 if (pci_load_and_free_saved_state(pdev, &vdev->pci_saved_state)) {
125 pr_info("%s: Couldn't reload %s saved state\n",
126 __func__, dev_name(&pdev->dev));
127
128 if (!vdev->reset_works)
129 return;
130
131 pci_save_state(pdev);
132 }
133
134
135
136
137
138 pci_write_config_word(pdev, PCI_COMMAND, PCI_COMMAND_INTX_DISABLE);
139
140 if (vdev->reset_works)
141 __pci_reset_function(pdev);
142
143 pci_restore_state(pdev);
144}
145
146static void vfio_pci_release(void *device_data)
147{
148 struct vfio_pci_device *vdev = device_data;
149
150 if (atomic_dec_and_test(&vdev->refcnt))
151 vfio_pci_disable(vdev);
152
153 module_put(THIS_MODULE);
154}
155
156static int vfio_pci_open(void *device_data)
157{
158 struct vfio_pci_device *vdev = device_data;
159
160 if (!try_module_get(THIS_MODULE))
161 return -ENODEV;
162
163 if (atomic_inc_return(&vdev->refcnt) == 1) {
164 int ret = vfio_pci_enable(vdev);
165 if (ret) {
166 module_put(THIS_MODULE);
167 return ret;
168 }
169 }
170
171 return 0;
172}
173
174static int vfio_pci_get_irq_count(struct vfio_pci_device *vdev, int irq_type)
175{
176 if (irq_type == VFIO_PCI_INTX_IRQ_INDEX) {
177 u8 pin;
178 pci_read_config_byte(vdev->pdev, PCI_INTERRUPT_PIN, &pin);
179 if (pin)
180 return 1;
181
182 } else if (irq_type == VFIO_PCI_MSI_IRQ_INDEX) {
183 u8 pos;
184 u16 flags;
185
186 pos = vdev->pdev->msi_cap;
187 if (pos) {
188 pci_read_config_word(vdev->pdev,
189 pos + PCI_MSI_FLAGS, &flags);
190
191 return 1 << (flags & PCI_MSI_FLAGS_QMASK);
192 }
193 } else if (irq_type == VFIO_PCI_MSIX_IRQ_INDEX) {
194 u8 pos;
195 u16 flags;
196
197 pos = vdev->pdev->msix_cap;
198 if (pos) {
199 pci_read_config_word(vdev->pdev,
200 pos + PCI_MSIX_FLAGS, &flags);
201
202 return (flags & PCI_MSIX_FLAGS_QSIZE) + 1;
203 }
204 } else if (irq_type == VFIO_PCI_ERR_IRQ_INDEX)
205 if (pci_is_pcie(vdev->pdev))
206 return 1;
207
208 return 0;
209}
210
211static long vfio_pci_ioctl(void *device_data,
212 unsigned int cmd, unsigned long arg)
213{
214 struct vfio_pci_device *vdev = device_data;
215 unsigned long minsz;
216
217 if (cmd == VFIO_DEVICE_GET_INFO) {
218 struct vfio_device_info info;
219
220 minsz = offsetofend(struct vfio_device_info, num_irqs);
221
222 if (copy_from_user(&info, (void __user *)arg, minsz))
223 return -EFAULT;
224
225 if (info.argsz < minsz)
226 return -EINVAL;
227
228 info.flags = VFIO_DEVICE_FLAGS_PCI;
229
230 if (vdev->reset_works)
231 info.flags |= VFIO_DEVICE_FLAGS_RESET;
232
233 info.num_regions = VFIO_PCI_NUM_REGIONS;
234 info.num_irqs = VFIO_PCI_NUM_IRQS;
235
236 return copy_to_user((void __user *)arg, &info, minsz);
237
238 } else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
239 struct pci_dev *pdev = vdev->pdev;
240 struct vfio_region_info info;
241
242 minsz = offsetofend(struct vfio_region_info, offset);
243
244 if (copy_from_user(&info, (void __user *)arg, minsz))
245 return -EFAULT;
246
247 if (info.argsz < minsz)
248 return -EINVAL;
249
250 switch (info.index) {
251 case VFIO_PCI_CONFIG_REGION_INDEX:
252 info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
253 info.size = pdev->cfg_size;
254 info.flags = VFIO_REGION_INFO_FLAG_READ |
255 VFIO_REGION_INFO_FLAG_WRITE;
256 break;
257 case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
258 info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
259 info.size = pci_resource_len(pdev, info.index);
260 if (!info.size) {
261 info.flags = 0;
262 break;
263 }
264
265 info.flags = VFIO_REGION_INFO_FLAG_READ |
266 VFIO_REGION_INFO_FLAG_WRITE;
267 if (pci_resource_flags(pdev, info.index) &
268 IORESOURCE_MEM && info.size >= PAGE_SIZE)
269 info.flags |= VFIO_REGION_INFO_FLAG_MMAP;
270 break;
271 case VFIO_PCI_ROM_REGION_INDEX:
272 {
273 void __iomem *io;
274 size_t size;
275
276 info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
277 info.flags = 0;
278
279
280 info.size = pci_resource_len(pdev, info.index);
281 if (!info.size)
282 break;
283
284
285 io = pci_map_rom(pdev, &size);
286 if (!io || !size) {
287 info.size = 0;
288 break;
289 }
290 pci_unmap_rom(pdev, io);
291
292 info.flags = VFIO_REGION_INFO_FLAG_READ;
293 break;
294 }
295 case VFIO_PCI_VGA_REGION_INDEX:
296 if (!vdev->has_vga)
297 return -EINVAL;
298
299 info.offset = VFIO_PCI_INDEX_TO_OFFSET(info.index);
300 info.size = 0xc0000;
301 info.flags = VFIO_REGION_INFO_FLAG_READ |
302 VFIO_REGION_INFO_FLAG_WRITE;
303
304 break;
305 default:
306 return -EINVAL;
307 }
308
309 return copy_to_user((void __user *)arg, &info, minsz);
310
311 } else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
312 struct vfio_irq_info info;
313
314 minsz = offsetofend(struct vfio_irq_info, count);
315
316 if (copy_from_user(&info, (void __user *)arg, minsz))
317 return -EFAULT;
318
319 if (info.argsz < minsz || info.index >= VFIO_PCI_NUM_IRQS)
320 return -EINVAL;
321
322 switch (info.index) {
323 case VFIO_PCI_INTX_IRQ_INDEX ... VFIO_PCI_MSIX_IRQ_INDEX:
324 break;
325 case VFIO_PCI_ERR_IRQ_INDEX:
326 if (pci_is_pcie(vdev->pdev))
327 break;
328
329 default:
330 return -EINVAL;
331 }
332
333 info.flags = VFIO_IRQ_INFO_EVENTFD;
334
335 info.count = vfio_pci_get_irq_count(vdev, info.index);
336
337 if (info.index == VFIO_PCI_INTX_IRQ_INDEX)
338 info.flags |= (VFIO_IRQ_INFO_MASKABLE |
339 VFIO_IRQ_INFO_AUTOMASKED);
340 else
341 info.flags |= VFIO_IRQ_INFO_NORESIZE;
342
343 return copy_to_user((void __user *)arg, &info, minsz);
344
345 } else if (cmd == VFIO_DEVICE_SET_IRQS) {
346 struct vfio_irq_set hdr;
347 u8 *data = NULL;
348 int ret = 0;
349
350 minsz = offsetofend(struct vfio_irq_set, count);
351
352 if (copy_from_user(&hdr, (void __user *)arg, minsz))
353 return -EFAULT;
354
355 if (hdr.argsz < minsz || hdr.index >= VFIO_PCI_NUM_IRQS ||
356 hdr.flags & ~(VFIO_IRQ_SET_DATA_TYPE_MASK |
357 VFIO_IRQ_SET_ACTION_TYPE_MASK))
358 return -EINVAL;
359
360 if (!(hdr.flags & VFIO_IRQ_SET_DATA_NONE)) {
361 size_t size;
362 int max = vfio_pci_get_irq_count(vdev, hdr.index);
363
364 if (hdr.flags & VFIO_IRQ_SET_DATA_BOOL)
365 size = sizeof(uint8_t);
366 else if (hdr.flags & VFIO_IRQ_SET_DATA_EVENTFD)
367 size = sizeof(int32_t);
368 else
369 return -EINVAL;
370
371 if (hdr.argsz - minsz < hdr.count * size ||
372 hdr.start >= max || hdr.start + hdr.count > max)
373 return -EINVAL;
374
375 data = memdup_user((void __user *)(arg + minsz),
376 hdr.count * size);
377 if (IS_ERR(data))
378 return PTR_ERR(data);
379 }
380
381 mutex_lock(&vdev->igate);
382
383 ret = vfio_pci_set_irqs_ioctl(vdev, hdr.flags, hdr.index,
384 hdr.start, hdr.count, data);
385
386 mutex_unlock(&vdev->igate);
387 kfree(data);
388
389 return ret;
390
391 } else if (cmd == VFIO_DEVICE_RESET)
392 return vdev->reset_works ?
393 pci_reset_function(vdev->pdev) : -EINVAL;
394
395 return -ENOTTY;
396}
397
398static ssize_t vfio_pci_rw(void *device_data, char __user *buf,
399 size_t count, loff_t *ppos, bool iswrite)
400{
401 unsigned int index = VFIO_PCI_OFFSET_TO_INDEX(*ppos);
402 struct vfio_pci_device *vdev = device_data;
403
404 if (index >= VFIO_PCI_NUM_REGIONS)
405 return -EINVAL;
406
407 switch (index) {
408 case VFIO_PCI_CONFIG_REGION_INDEX:
409 return vfio_pci_config_rw(vdev, buf, count, ppos, iswrite);
410
411 case VFIO_PCI_ROM_REGION_INDEX:
412 if (iswrite)
413 return -EINVAL;
414 return vfio_pci_bar_rw(vdev, buf, count, ppos, false);
415
416 case VFIO_PCI_BAR0_REGION_INDEX ... VFIO_PCI_BAR5_REGION_INDEX:
417 return vfio_pci_bar_rw(vdev, buf, count, ppos, iswrite);
418
419 case VFIO_PCI_VGA_REGION_INDEX:
420 return vfio_pci_vga_rw(vdev, buf, count, ppos, iswrite);
421 }
422
423 return -EINVAL;
424}
425
426static ssize_t vfio_pci_read(void *device_data, char __user *buf,
427 size_t count, loff_t *ppos)
428{
429 if (!count)
430 return 0;
431
432 return vfio_pci_rw(device_data, buf, count, ppos, false);
433}
434
435static ssize_t vfio_pci_write(void *device_data, const char __user *buf,
436 size_t count, loff_t *ppos)
437{
438 if (!count)
439 return 0;
440
441 return vfio_pci_rw(device_data, (char __user *)buf, count, ppos, true);
442}
443
444static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma)
445{
446 struct vfio_pci_device *vdev = device_data;
447 struct pci_dev *pdev = vdev->pdev;
448 unsigned int index;
449 u64 phys_len, req_len, pgoff, req_start;
450 int ret;
451
452 index = vma->vm_pgoff >> (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT);
453
454 if (vma->vm_end < vma->vm_start)
455 return -EINVAL;
456 if ((vma->vm_flags & VM_SHARED) == 0)
457 return -EINVAL;
458 if (index >= VFIO_PCI_ROM_REGION_INDEX)
459 return -EINVAL;
460 if (!(pci_resource_flags(pdev, index) & IORESOURCE_MEM))
461 return -EINVAL;
462
463 phys_len = pci_resource_len(pdev, index);
464 req_len = vma->vm_end - vma->vm_start;
465 pgoff = vma->vm_pgoff &
466 ((1U << (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT)) - 1);
467 req_start = pgoff << PAGE_SHIFT;
468
469 if (phys_len < PAGE_SIZE || req_start + req_len > phys_len)
470 return -EINVAL;
471
472 if (index == vdev->msix_bar) {
473
474
475
476
477
478
479
480
481
482
483 if (!(req_start >= vdev->msix_offset + vdev->msix_size ||
484 req_start + req_len <= vdev->msix_offset))
485 return -EINVAL;
486 }
487
488
489
490
491
492 if (!vdev->barmap[index]) {
493 ret = pci_request_selected_regions(pdev,
494 1 << index, "vfio-pci");
495 if (ret)
496 return ret;
497
498 vdev->barmap[index] = pci_iomap(pdev, index, 0);
499 }
500
501 vma->vm_private_data = vdev;
502 vma->vm_flags |= VM_IO | VM_DONTEXPAND | VM_DONTDUMP;
503 vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
504 vma->vm_pgoff = (pci_resource_start(pdev, index) >> PAGE_SHIFT) + pgoff;
505
506 return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
507 req_len, vma->vm_page_prot);
508}
509
510static const struct vfio_device_ops vfio_pci_ops = {
511 .name = "vfio-pci",
512 .open = vfio_pci_open,
513 .release = vfio_pci_release,
514 .ioctl = vfio_pci_ioctl,
515 .read = vfio_pci_read,
516 .write = vfio_pci_write,
517 .mmap = vfio_pci_mmap,
518};
519
520static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
521{
522 u8 type;
523 struct vfio_pci_device *vdev;
524 struct iommu_group *group;
525 int ret;
526
527 pci_read_config_byte(pdev, PCI_HEADER_TYPE, &type);
528 if ((type & PCI_HEADER_TYPE) != PCI_HEADER_TYPE_NORMAL)
529 return -EINVAL;
530
531 group = iommu_group_get(&pdev->dev);
532 if (!group)
533 return -EINVAL;
534
535 vdev = kzalloc(sizeof(*vdev), GFP_KERNEL);
536 if (!vdev) {
537 iommu_group_put(group);
538 return -ENOMEM;
539 }
540
541 vdev->pdev = pdev;
542 vdev->irq_type = VFIO_PCI_NUM_IRQS;
543 mutex_init(&vdev->igate);
544 spin_lock_init(&vdev->irqlock);
545 atomic_set(&vdev->refcnt, 0);
546
547 ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev);
548 if (ret) {
549 iommu_group_put(group);
550 kfree(vdev);
551 }
552
553 return ret;
554}
555
556static void vfio_pci_remove(struct pci_dev *pdev)
557{
558 struct vfio_pci_device *vdev;
559
560 vdev = vfio_del_group_dev(&pdev->dev);
561 if (!vdev)
562 return;
563
564 iommu_group_put(pdev->dev.iommu_group);
565 kfree(vdev);
566}
567
568static pci_ers_result_t vfio_pci_aer_err_detected(struct pci_dev *pdev,
569 pci_channel_state_t state)
570{
571 struct vfio_pci_device *vdev;
572 struct vfio_device *device;
573
574 device = vfio_device_get_from_dev(&pdev->dev);
575 if (device == NULL)
576 return PCI_ERS_RESULT_DISCONNECT;
577
578 vdev = vfio_device_data(device);
579 if (vdev == NULL) {
580 vfio_device_put(device);
581 return PCI_ERS_RESULT_DISCONNECT;
582 }
583
584 if (vdev->err_trigger)
585 eventfd_signal(vdev->err_trigger, 1);
586
587 vfio_device_put(device);
588
589 return PCI_ERS_RESULT_CAN_RECOVER;
590}
591
592static struct pci_error_handlers vfio_err_handlers = {
593 .error_detected = vfio_pci_aer_err_detected,
594};
595
596static struct pci_driver vfio_pci_driver = {
597 .name = "vfio-pci",
598 .id_table = NULL,
599 .probe = vfio_pci_probe,
600 .remove = vfio_pci_remove,
601 .err_handler = &vfio_err_handlers,
602};
603
604static void __exit vfio_pci_cleanup(void)
605{
606 pci_unregister_driver(&vfio_pci_driver);
607 vfio_pci_virqfd_exit();
608 vfio_pci_uninit_perm_bits();
609}
610
611static int __init vfio_pci_init(void)
612{
613 int ret;
614
615
616 ret = vfio_pci_init_perm_bits();
617 if (ret)
618 return ret;
619
620
621 ret = vfio_pci_virqfd_init();
622 if (ret)
623 goto out_virqfd;
624
625
626 ret = pci_register_driver(&vfio_pci_driver);
627 if (ret)
628 goto out_driver;
629
630 return 0;
631
632out_driver:
633 vfio_pci_virqfd_exit();
634out_virqfd:
635 vfio_pci_uninit_perm_bits();
636 return ret;
637}
638
639module_init(vfio_pci_init);
640module_exit(vfio_pci_cleanup);
641
642MODULE_VERSION(DRIVER_VERSION);
643MODULE_LICENSE("GPL v2");
644MODULE_AUTHOR(DRIVER_AUTHOR);
645MODULE_DESCRIPTION(DRIVER_DESC);
646
