1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Physical device callbacks for vfio_ccw
4 *
5 * Copyright IBM Corp. 2017
6 * Copyright Red Hat, Inc. 2019
7 *
8 * Author(s): Dong Jia Shi <bjsdjshi@linux.vnet.ibm.com>
9 * Xiao Feng Ren <renxiaof@linux.vnet.ibm.com>
10 * Cornelia Huck <cohuck@redhat.com>
11 */
12
13 #include <linux/vfio.h>
14 #include <linux/mdev.h>
15 #include <linux/nospec.h>
16 #include <linux/slab.h>
17
18 #include "vfio_ccw_private.h"
19
vfio_ccw_mdev_reset(struct mdev_device * mdev)20 static int vfio_ccw_mdev_reset(struct mdev_device *mdev)
21 {
22 struct vfio_ccw_private *private;
23 struct subchannel *sch;
24 int ret;
25
26 private = dev_get_drvdata(mdev_parent_dev(mdev));
27 sch = private->sch;
28 /*
29 * TODO:
30 * In the cureent stage, some things like "no I/O running" and "no
31 * interrupt pending" are clear, but we are not sure what other state
32 * we need to care about.
33 * There are still a lot more instructions need to be handled. We
34 * should come back here later.
35 */
36 ret = vfio_ccw_sch_quiesce(sch);
37 if (ret)
38 return ret;
39
40 ret = cio_enable_subchannel(sch, (u32)(unsigned long)sch);
41 if (!ret)
42 private->state = VFIO_CCW_STATE_IDLE;
43
44 return ret;
45 }
46
vfio_ccw_mdev_notifier(struct notifier_block * nb,unsigned long action,void * data)47 static int vfio_ccw_mdev_notifier(struct notifier_block *nb,
48 unsigned long action,
49 void *data)
50 {
51 struct vfio_ccw_private *private =
52 container_of(nb, struct vfio_ccw_private, nb);
53
54 /*
55 * Vendor drivers MUST unpin pages in response to an
56 * invalidation.
57 */
58 if (action == VFIO_IOMMU_NOTIFY_DMA_UNMAP) {
59 struct vfio_iommu_type1_dma_unmap *unmap = data;
60
61 if (!cp_iova_pinned(&private->cp, unmap->iova))
62 return NOTIFY_OK;
63
64 if (vfio_ccw_mdev_reset(private->mdev))
65 return NOTIFY_BAD;
66
67 cp_free(&private->cp);
68 return NOTIFY_OK;
69 }
70
71 return NOTIFY_DONE;
72 }
73
name_show(struct kobject * kobj,struct device * dev,char * buf)74 static ssize_t name_show(struct kobject *kobj, struct device *dev, char *buf)
75 {
76 return sprintf(buf, "I/O subchannel (Non-QDIO)\n");
77 }
78 static MDEV_TYPE_ATTR_RO(name);
79
device_api_show(struct kobject * kobj,struct device * dev,char * buf)80 static ssize_t device_api_show(struct kobject *kobj, struct device *dev,
81 char *buf)
82 {
83 return sprintf(buf, "%s\n", VFIO_DEVICE_API_CCW_STRING);
84 }
85 static MDEV_TYPE_ATTR_RO(device_api);
86
available_instances_show(struct kobject * kobj,struct device * dev,char * buf)87 static ssize_t available_instances_show(struct kobject *kobj,
88 struct device *dev, char *buf)
89 {
90 struct vfio_ccw_private *private = dev_get_drvdata(dev);
91
92 return sprintf(buf, "%d\n", atomic_read(&private->avail));
93 }
94 static MDEV_TYPE_ATTR_RO(available_instances);
95
96 static struct attribute *mdev_types_attrs[] = {
97 &mdev_type_attr_name.attr,
98 &mdev_type_attr_device_api.attr,
99 &mdev_type_attr_available_instances.attr,
100 NULL,
101 };
102
103 static struct attribute_group mdev_type_group = {
104 .name = "io",
105 .attrs = mdev_types_attrs,
106 };
107
108 static struct attribute_group *mdev_type_groups[] = {
109 &mdev_type_group,
110 NULL,
111 };
112
vfio_ccw_mdev_create(struct kobject * kobj,struct mdev_device * mdev)113 static int vfio_ccw_mdev_create(struct kobject *kobj, struct mdev_device *mdev)
114 {
115 struct vfio_ccw_private *private =
116 dev_get_drvdata(mdev_parent_dev(mdev));
117
118 if (private->state == VFIO_CCW_STATE_NOT_OPER)
119 return -ENODEV;
120
121 if (atomic_dec_if_positive(&private->avail) < 0)
122 return -EPERM;
123
124 private->mdev = mdev;
125 private->state = VFIO_CCW_STATE_IDLE;
126
127 VFIO_CCW_MSG_EVENT(2, "mdev %pUl, sch %x.%x.%04x: create\n",
128 mdev_uuid(mdev), private->sch->schid.cssid,
129 private->sch->schid.ssid,
130 private->sch->schid.sch_no);
131
132 return 0;
133 }
134
vfio_ccw_mdev_remove(struct mdev_device * mdev)135 static int vfio_ccw_mdev_remove(struct mdev_device *mdev)
136 {
137 struct vfio_ccw_private *private =
138 dev_get_drvdata(mdev_parent_dev(mdev));
139
140 VFIO_CCW_MSG_EVENT(2, "mdev %pUl, sch %x.%x.%04x: remove\n",
141 mdev_uuid(mdev), private->sch->schid.cssid,
142 private->sch->schid.ssid,
143 private->sch->schid.sch_no);
144
145 if ((private->state != VFIO_CCW_STATE_NOT_OPER) &&
146 (private->state != VFIO_CCW_STATE_STANDBY)) {
147 if (!vfio_ccw_sch_quiesce(private->sch))
148 private->state = VFIO_CCW_STATE_STANDBY;
149 /* The state will be NOT_OPER on error. */
150 }
151
152 cp_free(&private->cp);
153 private->mdev = NULL;
154 atomic_inc(&private->avail);
155
156 return 0;
157 }
158
vfio_ccw_mdev_open(struct mdev_device * mdev)159 static int vfio_ccw_mdev_open(struct mdev_device *mdev)
160 {
161 struct vfio_ccw_private *private =
162 dev_get_drvdata(mdev_parent_dev(mdev));
163 unsigned long events = VFIO_IOMMU_NOTIFY_DMA_UNMAP;
164 int ret;
165
166 private->nb.notifier_call = vfio_ccw_mdev_notifier;
167
168 ret = vfio_register_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
169 &events, &private->nb);
170 if (ret)
171 return ret;
172
173 ret = vfio_ccw_register_async_dev_regions(private);
174 if (ret)
175 vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
176 &private->nb);
177 return ret;
178 }
179
vfio_ccw_mdev_release(struct mdev_device * mdev)180 static void vfio_ccw_mdev_release(struct mdev_device *mdev)
181 {
182 struct vfio_ccw_private *private =
183 dev_get_drvdata(mdev_parent_dev(mdev));
184 int i;
185
186 if ((private->state != VFIO_CCW_STATE_NOT_OPER) &&
187 (private->state != VFIO_CCW_STATE_STANDBY)) {
188 if (!vfio_ccw_mdev_reset(mdev))
189 private->state = VFIO_CCW_STATE_STANDBY;
190 /* The state will be NOT_OPER on error. */
191 }
192
193 cp_free(&private->cp);
194 vfio_unregister_notifier(mdev_dev(mdev), VFIO_IOMMU_NOTIFY,
195 &private->nb);
196
197 for (i = 0; i < private->num_regions; i++)
198 private->region[i].ops->release(private, &private->region[i]);
199
200 private->num_regions = 0;
201 kfree(private->region);
202 private->region = NULL;
203 }
204
vfio_ccw_mdev_read_io_region(struct vfio_ccw_private * private,char __user * buf,size_t count,loff_t * ppos)205 static ssize_t vfio_ccw_mdev_read_io_region(struct vfio_ccw_private *private,
206 char __user *buf, size_t count,
207 loff_t *ppos)
208 {
209 loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
210 struct ccw_io_region *region;
211 int ret;
212
213 if (pos + count > sizeof(*region))
214 return -EINVAL;
215
216 mutex_lock(&private->io_mutex);
217 region = private->io_region;
218 if (copy_to_user(buf, (void *)region + pos, count))
219 ret = -EFAULT;
220 else
221 ret = count;
222 mutex_unlock(&private->io_mutex);
223 return ret;
224 }
225
vfio_ccw_mdev_read(struct mdev_device * mdev,char __user * buf,size_t count,loff_t * ppos)226 static ssize_t vfio_ccw_mdev_read(struct mdev_device *mdev,
227 char __user *buf,
228 size_t count,
229 loff_t *ppos)
230 {
231 unsigned int index = VFIO_CCW_OFFSET_TO_INDEX(*ppos);
232 struct vfio_ccw_private *private;
233
234 private = dev_get_drvdata(mdev_parent_dev(mdev));
235
236 if (index >= VFIO_CCW_NUM_REGIONS + private->num_regions)
237 return -EINVAL;
238
239 switch (index) {
240 case VFIO_CCW_CONFIG_REGION_INDEX:
241 return vfio_ccw_mdev_read_io_region(private, buf, count, ppos);
242 default:
243 index -= VFIO_CCW_NUM_REGIONS;
244 return private->region[index].ops->read(private, buf, count,
245 ppos);
246 }
247
248 return -EINVAL;
249 }
250
vfio_ccw_mdev_write_io_region(struct vfio_ccw_private * private,const char __user * buf,size_t count,loff_t * ppos)251 static ssize_t vfio_ccw_mdev_write_io_region(struct vfio_ccw_private *private,
252 const char __user *buf,
253 size_t count, loff_t *ppos)
254 {
255 loff_t pos = *ppos & VFIO_CCW_OFFSET_MASK;
256 struct ccw_io_region *region;
257 int ret;
258
259 if (pos + count > sizeof(*region))
260 return -EINVAL;
261
262 if (!mutex_trylock(&private->io_mutex))
263 return -EAGAIN;
264
265 region = private->io_region;
266 if (copy_from_user((void *)region + pos, buf, count)) {
267 ret = -EFAULT;
268 goto out_unlock;
269 }
270
271 vfio_ccw_fsm_event(private, VFIO_CCW_EVENT_IO_REQ);
272 if (region->ret_code != 0)
273 private->state = VFIO_CCW_STATE_IDLE;
274 ret = (region->ret_code != 0) ? region->ret_code : count;
275
276 out_unlock:
277 mutex_unlock(&private->io_mutex);
278 return ret;
279 }
280
vfio_ccw_mdev_write(struct mdev_device * mdev,const char __user * buf,size_t count,loff_t * ppos)281 static ssize_t vfio_ccw_mdev_write(struct mdev_device *mdev,
282 const char __user *buf,
283 size_t count,
284 loff_t *ppos)
285 {
286 unsigned int index = VFIO_CCW_OFFSET_TO_INDEX(*ppos);
287 struct vfio_ccw_private *private;
288
289 private = dev_get_drvdata(mdev_parent_dev(mdev));
290
291 if (index >= VFIO_CCW_NUM_REGIONS + private->num_regions)
292 return -EINVAL;
293
294 switch (index) {
295 case VFIO_CCW_CONFIG_REGION_INDEX:
296 return vfio_ccw_mdev_write_io_region(private, buf, count, ppos);
297 default:
298 index -= VFIO_CCW_NUM_REGIONS;
299 return private->region[index].ops->write(private, buf, count,
300 ppos);
301 }
302
303 return -EINVAL;
304 }
305
vfio_ccw_mdev_get_device_info(struct vfio_device_info * info,struct mdev_device * mdev)306 static int vfio_ccw_mdev_get_device_info(struct vfio_device_info *info,
307 struct mdev_device *mdev)
308 {
309 struct vfio_ccw_private *private;
310
311 private = dev_get_drvdata(mdev_parent_dev(mdev));
312 info->flags = VFIO_DEVICE_FLAGS_CCW | VFIO_DEVICE_FLAGS_RESET;
313 info->num_regions = VFIO_CCW_NUM_REGIONS + private->num_regions;
314 info->num_irqs = VFIO_CCW_NUM_IRQS;
315
316 return 0;
317 }
318
vfio_ccw_mdev_get_region_info(struct vfio_region_info * info,struct mdev_device * mdev,unsigned long arg)319 static int vfio_ccw_mdev_get_region_info(struct vfio_region_info *info,
320 struct mdev_device *mdev,
321 unsigned long arg)
322 {
323 struct vfio_ccw_private *private;
324 int i;
325
326 private = dev_get_drvdata(mdev_parent_dev(mdev));
327 switch (info->index) {
328 case VFIO_CCW_CONFIG_REGION_INDEX:
329 info->offset = 0;
330 info->size = sizeof(struct ccw_io_region);
331 info->flags = VFIO_REGION_INFO_FLAG_READ
332 | VFIO_REGION_INFO_FLAG_WRITE;
333 return 0;
334 default: /* all other regions are handled via capability chain */
335 {
336 struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
337 struct vfio_region_info_cap_type cap_type = {
338 .header.id = VFIO_REGION_INFO_CAP_TYPE,
339 .header.version = 1 };
340 int ret;
341
342 if (info->index >=
343 VFIO_CCW_NUM_REGIONS + private->num_regions)
344 return -EINVAL;
345
346 info->index = array_index_nospec(info->index,
347 VFIO_CCW_NUM_REGIONS +
348 private->num_regions);
349
350 i = info->index - VFIO_CCW_NUM_REGIONS;
351
352 info->offset = VFIO_CCW_INDEX_TO_OFFSET(info->index);
353 info->size = private->region[i].size;
354 info->flags = private->region[i].flags;
355
356 cap_type.type = private->region[i].type;
357 cap_type.subtype = private->region[i].subtype;
358
359 ret = vfio_info_add_capability(&caps, &cap_type.header,
360 sizeof(cap_type));
361 if (ret)
362 return ret;
363
364 info->flags |= VFIO_REGION_INFO_FLAG_CAPS;
365 if (info->argsz < sizeof(*info) + caps.size) {
366 info->argsz = sizeof(*info) + caps.size;
367 info->cap_offset = 0;
368 } else {
369 vfio_info_cap_shift(&caps, sizeof(*info));
370 if (copy_to_user((void __user *)arg + sizeof(*info),
371 caps.buf, caps.size)) {
372 kfree(caps.buf);
373 return -EFAULT;
374 }
375 info->cap_offset = sizeof(*info);
376 }
377
378 kfree(caps.buf);
379
380 }
381 }
382 return 0;
383 }
384
vfio_ccw_mdev_get_irq_info(struct vfio_irq_info * info)385 static int vfio_ccw_mdev_get_irq_info(struct vfio_irq_info *info)
386 {
387 if (info->index != VFIO_CCW_IO_IRQ_INDEX)
388 return -EINVAL;
389
390 info->count = 1;
391 info->flags = VFIO_IRQ_INFO_EVENTFD;
392
393 return 0;
394 }
395
vfio_ccw_mdev_set_irqs(struct mdev_device * mdev,uint32_t flags,void __user * data)396 static int vfio_ccw_mdev_set_irqs(struct mdev_device *mdev,
397 uint32_t flags,
398 void __user *data)
399 {
400 struct vfio_ccw_private *private;
401 struct eventfd_ctx **ctx;
402
403 if (!(flags & VFIO_IRQ_SET_ACTION_TRIGGER))
404 return -EINVAL;
405
406 private = dev_get_drvdata(mdev_parent_dev(mdev));
407 ctx = &private->io_trigger;
408
409 switch (flags & VFIO_IRQ_SET_DATA_TYPE_MASK) {
410 case VFIO_IRQ_SET_DATA_NONE:
411 {
412 if (*ctx)
413 eventfd_signal(*ctx, 1);
414 return 0;
415 }
416 case VFIO_IRQ_SET_DATA_BOOL:
417 {
418 uint8_t trigger;
419
420 if (get_user(trigger, (uint8_t __user *)data))
421 return -EFAULT;
422
423 if (trigger && *ctx)
424 eventfd_signal(*ctx, 1);
425 return 0;
426 }
427 case VFIO_IRQ_SET_DATA_EVENTFD:
428 {
429 int32_t fd;
430
431 if (get_user(fd, (int32_t __user *)data))
432 return -EFAULT;
433
434 if (fd == -1) {
435 if (*ctx)
436 eventfd_ctx_put(*ctx);
437 *ctx = NULL;
438 } else if (fd >= 0) {
439 struct eventfd_ctx *efdctx;
440
441 efdctx = eventfd_ctx_fdget(fd);
442 if (IS_ERR(efdctx))
443 return PTR_ERR(efdctx);
444
445 if (*ctx)
446 eventfd_ctx_put(*ctx);
447
448 *ctx = efdctx;
449 } else
450 return -EINVAL;
451
452 return 0;
453 }
454 default:
455 return -EINVAL;
456 }
457 }
458
vfio_ccw_register_dev_region(struct vfio_ccw_private * private,unsigned int subtype,const struct vfio_ccw_regops * ops,size_t size,u32 flags,void * data)459 int vfio_ccw_register_dev_region(struct vfio_ccw_private *private,
460 unsigned int subtype,
461 const struct vfio_ccw_regops *ops,
462 size_t size, u32 flags, void *data)
463 {
464 struct vfio_ccw_region *region;
465
466 region = krealloc(private->region,
467 (private->num_regions + 1) * sizeof(*region),
468 GFP_KERNEL);
469 if (!region)
470 return -ENOMEM;
471
472 private->region = region;
473 private->region[private->num_regions].type = VFIO_REGION_TYPE_CCW;
474 private->region[private->num_regions].subtype = subtype;
475 private->region[private->num_regions].ops = ops;
476 private->region[private->num_regions].size = size;
477 private->region[private->num_regions].flags = flags;
478 private->region[private->num_regions].data = data;
479
480 private->num_regions++;
481
482 return 0;
483 }
484
vfio_ccw_mdev_ioctl(struct mdev_device * mdev,unsigned int cmd,unsigned long arg)485 static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev,
486 unsigned int cmd,
487 unsigned long arg)
488 {
489 int ret = 0;
490 unsigned long minsz;
491
492 switch (cmd) {
493 case VFIO_DEVICE_GET_INFO:
494 {
495 struct vfio_device_info info;
496
497 minsz = offsetofend(struct vfio_device_info, num_irqs);
498
499 if (copy_from_user(&info, (void __user *)arg, minsz))
500 return -EFAULT;
501
502 if (info.argsz < minsz)
503 return -EINVAL;
504
505 ret = vfio_ccw_mdev_get_device_info(&info, mdev);
506 if (ret)
507 return ret;
508
509 return copy_to_user((void __user *)arg, &info, minsz);
510 }
511 case VFIO_DEVICE_GET_REGION_INFO:
512 {
513 struct vfio_region_info info;
514
515 minsz = offsetofend(struct vfio_region_info, offset);
516
517 if (copy_from_user(&info, (void __user *)arg, minsz))
518 return -EFAULT;
519
520 if (info.argsz < minsz)
521 return -EINVAL;
522
523 ret = vfio_ccw_mdev_get_region_info(&info, mdev, arg);
524 if (ret)
525 return ret;
526
527 return copy_to_user((void __user *)arg, &info, minsz);
528 }
529 case VFIO_DEVICE_GET_IRQ_INFO:
530 {
531 struct vfio_irq_info info;
532
533 minsz = offsetofend(struct vfio_irq_info, count);
534
535 if (copy_from_user(&info, (void __user *)arg, minsz))
536 return -EFAULT;
537
538 if (info.argsz < minsz || info.index >= VFIO_CCW_NUM_IRQS)
539 return -EINVAL;
540
541 ret = vfio_ccw_mdev_get_irq_info(&info);
542 if (ret)
543 return ret;
544
545 if (info.count == -1)
546 return -EINVAL;
547
548 return copy_to_user((void __user *)arg, &info, minsz);
549 }
550 case VFIO_DEVICE_SET_IRQS:
551 {
552 struct vfio_irq_set hdr;
553 size_t data_size;
554 void __user *data;
555
556 minsz = offsetofend(struct vfio_irq_set, count);
557
558 if (copy_from_user(&hdr, (void __user *)arg, minsz))
559 return -EFAULT;
560
561 ret = vfio_set_irqs_validate_and_prepare(&hdr, 1,
562 VFIO_CCW_NUM_IRQS,
563 &data_size);
564 if (ret)
565 return ret;
566
567 data = (void __user *)(arg + minsz);
568 return vfio_ccw_mdev_set_irqs(mdev, hdr.flags, data);
569 }
570 case VFIO_DEVICE_RESET:
571 return vfio_ccw_mdev_reset(mdev);
572 default:
573 return -ENOTTY;
574 }
575 }
576
577 static const struct mdev_parent_ops vfio_ccw_mdev_ops = {
578 .owner = THIS_MODULE,
579 .supported_type_groups = mdev_type_groups,
580 .create = vfio_ccw_mdev_create,
581 .remove = vfio_ccw_mdev_remove,
582 .open = vfio_ccw_mdev_open,
583 .release = vfio_ccw_mdev_release,
584 .read = vfio_ccw_mdev_read,
585 .write = vfio_ccw_mdev_write,
586 .ioctl = vfio_ccw_mdev_ioctl,
587 };
588
vfio_ccw_mdev_reg(struct subchannel * sch)589 int vfio_ccw_mdev_reg(struct subchannel *sch)
590 {
591 return mdev_register_device(&sch->dev, &vfio_ccw_mdev_ops);
592 }
593
vfio_ccw_mdev_unreg(struct subchannel * sch)594 void vfio_ccw_mdev_unreg(struct subchannel *sch)
595 {
596 mdev_unregister_device(&sch->dev);
597 }
598