xref: /linux/drivers/iommu/iommufd/hw_pagetable.c (revision 4b01712311c6e209137c4fa3e7d7920ec509456a) 
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (c) 2021-2022, NVIDIA CORPORATION & AFFILIATES
4  */
5 #include <linux/iommu.h>
6 #include <uapi/linux/iommufd.h>
7 
8 #include "../iommu-priv.h"
9 #include "iommufd_private.h"
10 
11 static void __iommufd_hwpt_destroy(struct iommufd_hw_pagetable *hwpt)
12 {
13 	if (hwpt->domain)
14 		iommu_domain_free(hwpt->domain);
15 
16 	if (hwpt->fault)
17 		refcount_dec(&hwpt->fault->obj.users);
18 }
19 
20 void iommufd_hwpt_paging_destroy(struct iommufd_object *obj)
21 {
22 	struct iommufd_hwpt_paging *hwpt_paging =
23 		container_of(obj, struct iommufd_hwpt_paging, common.obj);
24 
25 	if (!list_empty(&hwpt_paging->hwpt_item)) {
26 		mutex_lock(&hwpt_paging->ioas->mutex);
27 		list_del(&hwpt_paging->hwpt_item);
28 		mutex_unlock(&hwpt_paging->ioas->mutex);
29 
30 		iopt_table_remove_domain(&hwpt_paging->ioas->iopt,
31 					 hwpt_paging->common.domain);
32 	}
33 
34 	__iommufd_hwpt_destroy(&hwpt_paging->common);
35 	refcount_dec(&hwpt_paging->ioas->obj.users);
36 }
37 
38 void iommufd_hwpt_paging_abort(struct iommufd_object *obj)
39 {
40 	struct iommufd_hwpt_paging *hwpt_paging =
41 		container_of(obj, struct iommufd_hwpt_paging, common.obj);
42 
43 	/* The ioas->mutex must be held until finalize is called. */
44 	lockdep_assert_held(&hwpt_paging->ioas->mutex);
45 
46 	if (!list_empty(&hwpt_paging->hwpt_item)) {
47 		list_del_init(&hwpt_paging->hwpt_item);
48 		iopt_table_remove_domain(&hwpt_paging->ioas->iopt,
49 					 hwpt_paging->common.domain);
50 	}
51 	iommufd_hwpt_paging_destroy(obj);
52 }
53 
54 void iommufd_hwpt_nested_destroy(struct iommufd_object *obj)
55 {
56 	struct iommufd_hwpt_nested *hwpt_nested =
57 		container_of(obj, struct iommufd_hwpt_nested, common.obj);
58 
59 	__iommufd_hwpt_destroy(&hwpt_nested->common);
60 	if (hwpt_nested->viommu)
61 		refcount_dec(&hwpt_nested->viommu->obj.users);
62 	else
63 		refcount_dec(&hwpt_nested->parent->common.obj.users);
64 }
65 
66 void iommufd_hwpt_nested_abort(struct iommufd_object *obj)
67 {
68 	iommufd_hwpt_nested_destroy(obj);
69 }
70 
71 static int
72 iommufd_hwpt_paging_enforce_cc(struct iommufd_hwpt_paging *hwpt_paging)
73 {
74 	struct iommu_domain *paging_domain = hwpt_paging->common.domain;
75 
76 	if (hwpt_paging->enforce_cache_coherency)
77 		return 0;
78 
79 	if (paging_domain->ops->enforce_cache_coherency)
80 		hwpt_paging->enforce_cache_coherency =
81 			paging_domain->ops->enforce_cache_coherency(
82 				paging_domain);
83 	if (!hwpt_paging->enforce_cache_coherency)
84 		return -EINVAL;
85 	return 0;
86 }
87 
88 /**
89  * iommufd_hwpt_paging_alloc() - Get a PAGING iommu_domain for a device
90  * @ictx: iommufd context
91  * @ioas: IOAS to associate the domain with
92  * @idev: Device to get an iommu_domain for
93  * @flags: Flags from userspace
94  * @immediate_attach: True if idev should be attached to the hwpt
95  * @user_data: The user provided driver specific data describing the domain to
96  *             create
97  *
98  * Allocate a new iommu_domain and return it as a hw_pagetable. The HWPT
99  * will be linked to the given ioas and upon return the underlying iommu_domain
100  * is fully popoulated.
101  *
102  * The caller must hold the ioas->mutex until after
103  * iommufd_object_abort_and_destroy() or iommufd_object_finalize() is called on
104  * the returned hwpt.
105  */
106 struct iommufd_hwpt_paging *
107 iommufd_hwpt_paging_alloc(struct iommufd_ctx *ictx, struct iommufd_ioas *ioas,
108 			  struct iommufd_device *idev, u32 flags,
109 			  bool immediate_attach,
110 			  const struct iommu_user_data *user_data)
111 {
112 	const u32 valid_flags = IOMMU_HWPT_ALLOC_NEST_PARENT |
113 				IOMMU_HWPT_ALLOC_DIRTY_TRACKING;
114 	const struct iommu_ops *ops = dev_iommu_ops(idev->dev);
115 	struct iommufd_hwpt_paging *hwpt_paging;
116 	struct iommufd_hw_pagetable *hwpt;
117 	int rc;
118 
119 	lockdep_assert_held(&ioas->mutex);
120 
121 	if ((flags || user_data) && !ops->domain_alloc_user)
122 		return ERR_PTR(-EOPNOTSUPP);
123 	if (flags & ~valid_flags)
124 		return ERR_PTR(-EOPNOTSUPP);
125 	if ((flags & IOMMU_HWPT_ALLOC_DIRTY_TRACKING) &&
126 	    !device_iommu_capable(idev->dev, IOMMU_CAP_DIRTY_TRACKING))
127 		return ERR_PTR(-EOPNOTSUPP);
128 
129 	hwpt_paging = __iommufd_object_alloc(
130 		ictx, hwpt_paging, IOMMUFD_OBJ_HWPT_PAGING, common.obj);
131 	if (IS_ERR(hwpt_paging))
132 		return ERR_CAST(hwpt_paging);
133 	hwpt = &hwpt_paging->common;
134 
135 	INIT_LIST_HEAD(&hwpt_paging->hwpt_item);
136 	/* Pairs with iommufd_hw_pagetable_destroy() */
137 	refcount_inc(&ioas->obj.users);
138 	hwpt_paging->ioas = ioas;
139 	hwpt_paging->nest_parent = flags & IOMMU_HWPT_ALLOC_NEST_PARENT;
140 
141 	if (ops->domain_alloc_user) {
142 		hwpt->domain = ops->domain_alloc_user(idev->dev, flags, NULL,
143 						      user_data);
144 		if (IS_ERR(hwpt->domain)) {
145 			rc = PTR_ERR(hwpt->domain);
146 			hwpt->domain = NULL;
147 			goto out_abort;
148 		}
149 		hwpt->domain->owner = ops;
150 	} else {
151 		hwpt->domain = iommu_paging_domain_alloc(idev->dev);
152 		if (IS_ERR(hwpt->domain)) {
153 			rc = PTR_ERR(hwpt->domain);
154 			hwpt->domain = NULL;
155 			goto out_abort;
156 		}
157 	}
158 
159 	/*
160 	 * Set the coherency mode before we do iopt_table_add_domain() as some
161 	 * iommus have a per-PTE bit that controls it and need to decide before
162 	 * doing any maps. It is an iommu driver bug to report
163 	 * IOMMU_CAP_ENFORCE_CACHE_COHERENCY but fail enforce_cache_coherency on
164 	 * a new domain.
165 	 *
166 	 * The cache coherency mode must be configured here and unchanged later.
167 	 * Note that a HWPT (non-CC) created for a device (non-CC) can be later
168 	 * reused by another device (either non-CC or CC). However, A HWPT (CC)
169 	 * created for a device (CC) cannot be reused by another device (non-CC)
170 	 * but only devices (CC). Instead user space in this case would need to
171 	 * allocate a separate HWPT (non-CC).
172 	 */
173 	if (idev->enforce_cache_coherency) {
174 		rc = iommufd_hwpt_paging_enforce_cc(hwpt_paging);
175 		if (WARN_ON(rc))
176 			goto out_abort;
177 	}
178 
179 	/*
180 	 * immediate_attach exists only to accommodate iommu drivers that cannot
181 	 * directly allocate a domain. These drivers do not finish creating the
182 	 * domain until attach is completed. Thus we must have this call
183 	 * sequence. Once those drivers are fixed this should be removed.
184 	 */
185 	if (immediate_attach) {
186 		rc = iommufd_hw_pagetable_attach(hwpt, idev);
187 		if (rc)
188 			goto out_abort;
189 	}
190 
191 	rc = iopt_table_add_domain(&ioas->iopt, hwpt->domain);
192 	if (rc)
193 		goto out_detach;
194 	list_add_tail(&hwpt_paging->hwpt_item, &ioas->hwpt_list);
195 	return hwpt_paging;
196 
197 out_detach:
198 	if (immediate_attach)
199 		iommufd_hw_pagetable_detach(idev);
200 out_abort:
201 	iommufd_object_abort_and_destroy(ictx, &hwpt->obj);
202 	return ERR_PTR(rc);
203 }
204 
205 /**
206  * iommufd_hwpt_nested_alloc() - Get a NESTED iommu_domain for a device
207  * @ictx: iommufd context
208  * @parent: Parent PAGING-type hwpt to associate the domain with
209  * @idev: Device to get an iommu_domain for
210  * @flags: Flags from userspace
211  * @user_data: user_data pointer. Must be valid
212  *
213  * Allocate a new iommu_domain (must be IOMMU_DOMAIN_NESTED) and return it as
214  * a NESTED hw_pagetable. The given parent PAGING-type hwpt must be capable of
215  * being a parent.
216  */
217 static struct iommufd_hwpt_nested *
218 iommufd_hwpt_nested_alloc(struct iommufd_ctx *ictx,
219 			  struct iommufd_hwpt_paging *parent,
220 			  struct iommufd_device *idev, u32 flags,
221 			  const struct iommu_user_data *user_data)
222 {
223 	const struct iommu_ops *ops = dev_iommu_ops(idev->dev);
224 	struct iommufd_hwpt_nested *hwpt_nested;
225 	struct iommufd_hw_pagetable *hwpt;
226 	int rc;
227 
228 	if ((flags & ~IOMMU_HWPT_FAULT_ID_VALID) ||
229 	    !user_data->len || !ops->domain_alloc_user)
230 		return ERR_PTR(-EOPNOTSUPP);
231 	if (parent->auto_domain || !parent->nest_parent ||
232 	    parent->common.domain->owner != ops)
233 		return ERR_PTR(-EINVAL);
234 
235 	hwpt_nested = __iommufd_object_alloc(
236 		ictx, hwpt_nested, IOMMUFD_OBJ_HWPT_NESTED, common.obj);
237 	if (IS_ERR(hwpt_nested))
238 		return ERR_CAST(hwpt_nested);
239 	hwpt = &hwpt_nested->common;
240 
241 	refcount_inc(&parent->common.obj.users);
242 	hwpt_nested->parent = parent;
243 
244 	hwpt->domain = ops->domain_alloc_user(idev->dev,
245 					      flags & ~IOMMU_HWPT_FAULT_ID_VALID,
246 					      parent->common.domain, user_data);
247 	if (IS_ERR(hwpt->domain)) {
248 		rc = PTR_ERR(hwpt->domain);
249 		hwpt->domain = NULL;
250 		goto out_abort;
251 	}
252 	hwpt->domain->owner = ops;
253 
254 	if (WARN_ON_ONCE(hwpt->domain->type != IOMMU_DOMAIN_NESTED)) {
255 		rc = -EINVAL;
256 		goto out_abort;
257 	}
258 	return hwpt_nested;
259 
260 out_abort:
261 	iommufd_object_abort_and_destroy(ictx, &hwpt->obj);
262 	return ERR_PTR(rc);
263 }
264 
265 /**
266  * iommufd_viommu_alloc_hwpt_nested() - Get a hwpt_nested for a vIOMMU
267  * @viommu: vIOMMU ojbect to associate the hwpt_nested/domain with
268  * @flags: Flags from userspace
269  * @user_data: user_data pointer. Must be valid
270  *
271  * Allocate a new IOMMU_DOMAIN_NESTED for a vIOMMU and return it as a NESTED
272  * hw_pagetable.
273  */
274 static struct iommufd_hwpt_nested *
275 iommufd_viommu_alloc_hwpt_nested(struct iommufd_viommu *viommu, u32 flags,
276 				 const struct iommu_user_data *user_data)
277 {
278 	struct iommufd_hwpt_nested *hwpt_nested;
279 	struct iommufd_hw_pagetable *hwpt;
280 	int rc;
281 
282 	if (!user_data->len)
283 		return ERR_PTR(-EOPNOTSUPP);
284 	if (!viommu->ops || !viommu->ops->alloc_domain_nested)
285 		return ERR_PTR(-EOPNOTSUPP);
286 
287 	hwpt_nested = __iommufd_object_alloc(
288 		viommu->ictx, hwpt_nested, IOMMUFD_OBJ_HWPT_NESTED, common.obj);
289 	if (IS_ERR(hwpt_nested))
290 		return ERR_CAST(hwpt_nested);
291 	hwpt = &hwpt_nested->common;
292 
293 	hwpt_nested->viommu = viommu;
294 	refcount_inc(&viommu->obj.users);
295 	hwpt_nested->parent = viommu->hwpt;
296 
297 	hwpt->domain =
298 		viommu->ops->alloc_domain_nested(viommu, flags, user_data);
299 	if (IS_ERR(hwpt->domain)) {
300 		rc = PTR_ERR(hwpt->domain);
301 		hwpt->domain = NULL;
302 		goto out_abort;
303 	}
304 	hwpt->domain->owner = viommu->iommu_dev->ops;
305 
306 	if (WARN_ON_ONCE(hwpt->domain->type != IOMMU_DOMAIN_NESTED)) {
307 		rc = -EINVAL;
308 		goto out_abort;
309 	}
310 	return hwpt_nested;
311 
312 out_abort:
313 	iommufd_object_abort_and_destroy(viommu->ictx, &hwpt->obj);
314 	return ERR_PTR(rc);
315 }
316 
317 int iommufd_hwpt_alloc(struct iommufd_ucmd *ucmd)
318 {
319 	struct iommu_hwpt_alloc *cmd = ucmd->cmd;
320 	const struct iommu_user_data user_data = {
321 		.type = cmd->data_type,
322 		.uptr = u64_to_user_ptr(cmd->data_uptr),
323 		.len = cmd->data_len,
324 	};
325 	struct iommufd_hw_pagetable *hwpt;
326 	struct iommufd_ioas *ioas = NULL;
327 	struct iommufd_object *pt_obj;
328 	struct iommufd_device *idev;
329 	int rc;
330 
331 	if (cmd->__reserved)
332 		return -EOPNOTSUPP;
333 	if ((cmd->data_type == IOMMU_HWPT_DATA_NONE && cmd->data_len) ||
334 	    (cmd->data_type != IOMMU_HWPT_DATA_NONE && !cmd->data_len))
335 		return -EINVAL;
336 
337 	idev = iommufd_get_device(ucmd, cmd->dev_id);
338 	if (IS_ERR(idev))
339 		return PTR_ERR(idev);
340 
341 	pt_obj = iommufd_get_object(ucmd->ictx, cmd->pt_id, IOMMUFD_OBJ_ANY);
342 	if (IS_ERR(pt_obj)) {
343 		rc = -EINVAL;
344 		goto out_put_idev;
345 	}
346 
347 	if (pt_obj->type == IOMMUFD_OBJ_IOAS) {
348 		struct iommufd_hwpt_paging *hwpt_paging;
349 
350 		ioas = container_of(pt_obj, struct iommufd_ioas, obj);
351 		mutex_lock(&ioas->mutex);
352 		hwpt_paging = iommufd_hwpt_paging_alloc(
353 			ucmd->ictx, ioas, idev, cmd->flags, false,
354 			user_data.len ? &user_data : NULL);
355 		if (IS_ERR(hwpt_paging)) {
356 			rc = PTR_ERR(hwpt_paging);
357 			goto out_unlock;
358 		}
359 		hwpt = &hwpt_paging->common;
360 	} else if (pt_obj->type == IOMMUFD_OBJ_HWPT_PAGING) {
361 		struct iommufd_hwpt_nested *hwpt_nested;
362 
363 		hwpt_nested = iommufd_hwpt_nested_alloc(
364 			ucmd->ictx,
365 			container_of(pt_obj, struct iommufd_hwpt_paging,
366 				     common.obj),
367 			idev, cmd->flags, &user_data);
368 		if (IS_ERR(hwpt_nested)) {
369 			rc = PTR_ERR(hwpt_nested);
370 			goto out_unlock;
371 		}
372 		hwpt = &hwpt_nested->common;
373 	} else if (pt_obj->type == IOMMUFD_OBJ_VIOMMU) {
374 		struct iommufd_hwpt_nested *hwpt_nested;
375 		struct iommufd_viommu *viommu;
376 
377 		viommu = container_of(pt_obj, struct iommufd_viommu, obj);
378 		if (viommu->iommu_dev != __iommu_get_iommu_dev(idev->dev)) {
379 			rc = -EINVAL;
380 			goto out_unlock;
381 		}
382 		hwpt_nested = iommufd_viommu_alloc_hwpt_nested(
383 			viommu, cmd->flags, &user_data);
384 		if (IS_ERR(hwpt_nested)) {
385 			rc = PTR_ERR(hwpt_nested);
386 			goto out_unlock;
387 		}
388 		hwpt = &hwpt_nested->common;
389 	} else {
390 		rc = -EINVAL;
391 		goto out_put_pt;
392 	}
393 
394 	if (cmd->flags & IOMMU_HWPT_FAULT_ID_VALID) {
395 		struct iommufd_fault *fault;
396 
397 		fault = iommufd_get_fault(ucmd, cmd->fault_id);
398 		if (IS_ERR(fault)) {
399 			rc = PTR_ERR(fault);
400 			goto out_hwpt;
401 		}
402 		hwpt->fault = fault;
403 		hwpt->domain->iopf_handler = iommufd_fault_iopf_handler;
404 		hwpt->domain->fault_data = hwpt;
405 		refcount_inc(&fault->obj.users);
406 		iommufd_put_object(ucmd->ictx, &fault->obj);
407 	}
408 
409 	cmd->out_hwpt_id = hwpt->obj.id;
410 	rc = iommufd_ucmd_respond(ucmd, sizeof(*cmd));
411 	if (rc)
412 		goto out_hwpt;
413 	iommufd_object_finalize(ucmd->ictx, &hwpt->obj);
414 	goto out_unlock;
415 
416 out_hwpt:
417 	iommufd_object_abort_and_destroy(ucmd->ictx, &hwpt->obj);
418 out_unlock:
419 	if (ioas)
420 		mutex_unlock(&ioas->mutex);
421 out_put_pt:
422 	iommufd_put_object(ucmd->ictx, pt_obj);
423 out_put_idev:
424 	iommufd_put_object(ucmd->ictx, &idev->obj);
425 	return rc;
426 }
427 
428 int iommufd_hwpt_set_dirty_tracking(struct iommufd_ucmd *ucmd)
429 {
430 	struct iommu_hwpt_set_dirty_tracking *cmd = ucmd->cmd;
431 	struct iommufd_hwpt_paging *hwpt_paging;
432 	struct iommufd_ioas *ioas;
433 	int rc = -EOPNOTSUPP;
434 	bool enable;
435 
436 	if (cmd->flags & ~IOMMU_HWPT_DIRTY_TRACKING_ENABLE)
437 		return rc;
438 
439 	hwpt_paging = iommufd_get_hwpt_paging(ucmd, cmd->hwpt_id);
440 	if (IS_ERR(hwpt_paging))
441 		return PTR_ERR(hwpt_paging);
442 
443 	ioas = hwpt_paging->ioas;
444 	enable = cmd->flags & IOMMU_HWPT_DIRTY_TRACKING_ENABLE;
445 
446 	rc = iopt_set_dirty_tracking(&ioas->iopt, hwpt_paging->common.domain,
447 				     enable);
448 
449 	iommufd_put_object(ucmd->ictx, &hwpt_paging->common.obj);
450 	return rc;
451 }
452 
453 int iommufd_hwpt_get_dirty_bitmap(struct iommufd_ucmd *ucmd)
454 {
455 	struct iommu_hwpt_get_dirty_bitmap *cmd = ucmd->cmd;
456 	struct iommufd_hwpt_paging *hwpt_paging;
457 	struct iommufd_ioas *ioas;
458 	int rc = -EOPNOTSUPP;
459 
460 	if ((cmd->flags & ~(IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR)) ||
461 	    cmd->__reserved)
462 		return -EOPNOTSUPP;
463 
464 	hwpt_paging = iommufd_get_hwpt_paging(ucmd, cmd->hwpt_id);
465 	if (IS_ERR(hwpt_paging))
466 		return PTR_ERR(hwpt_paging);
467 
468 	ioas = hwpt_paging->ioas;
469 	rc = iopt_read_and_clear_dirty_data(
470 		&ioas->iopt, hwpt_paging->common.domain, cmd->flags, cmd);
471 
472 	iommufd_put_object(ucmd->ictx, &hwpt_paging->common.obj);
473 	return rc;
474 }
475 
476 int iommufd_hwpt_invalidate(struct iommufd_ucmd *ucmd)
477 {
478 	struct iommu_hwpt_invalidate *cmd = ucmd->cmd;
479 	struct iommu_user_data_array data_array = {
480 		.type = cmd->data_type,
481 		.uptr = u64_to_user_ptr(cmd->data_uptr),
482 		.entry_len = cmd->entry_len,
483 		.entry_num = cmd->entry_num,
484 	};
485 	struct iommufd_object *pt_obj;
486 	u32 done_num = 0;
487 	int rc;
488 
489 	if (cmd->__reserved) {
490 		rc = -EOPNOTSUPP;
491 		goto out;
492 	}
493 
494 	if (cmd->entry_num && (!cmd->data_uptr || !cmd->entry_len)) {
495 		rc = -EINVAL;
496 		goto out;
497 	}
498 
499 	pt_obj = iommufd_get_object(ucmd->ictx, cmd->hwpt_id, IOMMUFD_OBJ_ANY);
500 	if (IS_ERR(pt_obj)) {
501 		rc = PTR_ERR(pt_obj);
502 		goto out;
503 	}
504 	if (pt_obj->type == IOMMUFD_OBJ_HWPT_NESTED) {
505 		struct iommufd_hw_pagetable *hwpt =
506 			container_of(pt_obj, struct iommufd_hw_pagetable, obj);
507 
508 		if (!hwpt->domain->ops ||
509 		    !hwpt->domain->ops->cache_invalidate_user) {
510 			rc = -EOPNOTSUPP;
511 			goto out_put_pt;
512 		}
513 		rc = hwpt->domain->ops->cache_invalidate_user(hwpt->domain,
514 							      &data_array);
515 	} else if (pt_obj->type == IOMMUFD_OBJ_VIOMMU) {
516 		struct iommufd_viommu *viommu =
517 			container_of(pt_obj, struct iommufd_viommu, obj);
518 
519 		if (!viommu->ops || !viommu->ops->cache_invalidate) {
520 			rc = -EOPNOTSUPP;
521 			goto out_put_pt;
522 		}
523 		rc = viommu->ops->cache_invalidate(viommu, &data_array);
524 	} else {
525 		rc = -EINVAL;
526 		goto out_put_pt;
527 	}
528 
529 	done_num = data_array.entry_num;
530 
531 out_put_pt:
532 	iommufd_put_object(ucmd->ictx, pt_obj);
533 out:
534 	cmd->entry_num = done_num;
535 	if (iommufd_ucmd_respond(ucmd, sizeof(*cmd)))
536 		return -EFAULT;
537 	return rc;
538 }
539