1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * VFIO: IOMMU DMA mapping support for TCE on POWER
4 *
5 * Copyright (C) 2013 IBM Corp. All rights reserved.
6 * Author: Alexey Kardashevskiy <aik@ozlabs.ru>
7 *
8 * Derived from original vfio_iommu_type1.c:
9 * Copyright (C) 2012 Red Hat, Inc. All rights reserved.
10 * Author: Alex Williamson <alex.williamson@redhat.com>
11 */
12
13 #include <linux/module.h>
14 #include <linux/pci.h>
15 #include <linux/slab.h>
16 #include <linux/uaccess.h>
17 #include <linux/err.h>
18 #include <linux/vfio.h>
19 #include <linux/vmalloc.h>
20 #include <linux/sched/mm.h>
21 #include <linux/sched/signal.h>
22 #include <linux/mm.h>
23 #include "vfio.h"
24
25 #include <asm/iommu.h>
26 #include <asm/tce.h>
27 #include <asm/mmu_context.h>
28
29 #define DRIVER_VERSION "0.1"
30 #define DRIVER_AUTHOR "aik@ozlabs.ru"
31 #define DRIVER_DESC "VFIO IOMMU SPAPR TCE"
32
33 static void tce_iommu_detach_group(void *iommu_data,
34 struct iommu_group *iommu_group);
35
36 /*
37 * VFIO IOMMU fd for SPAPR_TCE IOMMU implementation
38 *
39 * This code handles mapping and unmapping of user data buffers
40 * into DMA'ble space using the IOMMU
41 */
42
43 struct tce_iommu_group {
44 struct list_head next;
45 struct iommu_group *grp;
46 };
47
48 /*
49 * A container needs to remember which preregistered region it has
50 * referenced to do proper cleanup at the userspace process exit.
51 */
52 struct tce_iommu_prereg {
53 struct list_head next;
54 struct mm_iommu_table_group_mem_t *mem;
55 };
56
57 /*
58 * The container descriptor supports only a single group per container.
59 * Required by the API as the container is not supplied with the IOMMU group
60 * at the moment of initialization.
61 */
62 struct tce_container {
63 struct mutex lock;
64 bool enabled;
65 bool v2;
66 bool def_window_pending;
67 unsigned long locked_pages;
68 struct mm_struct *mm;
69 struct iommu_table *tables[IOMMU_TABLE_GROUP_MAX_TABLES];
70 struct list_head group_list;
71 struct list_head prereg_list;
72 };
73
tce_iommu_mm_set(struct tce_container * container)74 static long tce_iommu_mm_set(struct tce_container *container)
75 {
76 if (container->mm) {
77 if (container->mm == current->mm)
78 return 0;
79 return -EPERM;
80 }
81 BUG_ON(!current->mm);
82 container->mm = current->mm;
83 mmgrab(container->mm);
84
85 return 0;
86 }
87
tce_iommu_prereg_free(struct tce_container * container,struct tce_iommu_prereg * tcemem)88 static long tce_iommu_prereg_free(struct tce_container *container,
89 struct tce_iommu_prereg *tcemem)
90 {
91 long ret;
92
93 ret = mm_iommu_put(container->mm, tcemem->mem);
94 if (ret)
95 return ret;
96
97 list_del(&tcemem->next);
98 kfree(tcemem);
99
100 return 0;
101 }
102
tce_iommu_unregister_pages(struct tce_container * container,__u64 vaddr,__u64 size)103 static long tce_iommu_unregister_pages(struct tce_container *container,
104 __u64 vaddr, __u64 size)
105 {
106 struct mm_iommu_table_group_mem_t *mem;
107 struct tce_iommu_prereg *tcemem;
108 bool found = false;
109 long ret;
110
111 if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK))
112 return -EINVAL;
113
114 mem = mm_iommu_get(container->mm, vaddr, size >> PAGE_SHIFT);
115 if (!mem)
116 return -ENOENT;
117
118 list_for_each_entry(tcemem, &container->prereg_list, next) {
119 if (tcemem->mem == mem) {
120 found = true;
121 break;
122 }
123 }
124
125 if (!found)
126 ret = -ENOENT;
127 else
128 ret = tce_iommu_prereg_free(container, tcemem);
129
130 mm_iommu_put(container->mm, mem);
131
132 return ret;
133 }
134
tce_iommu_register_pages(struct tce_container * container,__u64 vaddr,__u64 size)135 static long tce_iommu_register_pages(struct tce_container *container,
136 __u64 vaddr, __u64 size)
137 {
138 long ret = 0;
139 struct mm_iommu_table_group_mem_t *mem = NULL;
140 struct tce_iommu_prereg *tcemem;
141 unsigned long entries = size >> PAGE_SHIFT;
142
143 if ((vaddr & ~PAGE_MASK) || (size & ~PAGE_MASK) ||
144 ((vaddr + size) < vaddr))
145 return -EINVAL;
146
147 mem = mm_iommu_get(container->mm, vaddr, entries);
148 if (mem) {
149 list_for_each_entry(tcemem, &container->prereg_list, next) {
150 if (tcemem->mem == mem) {
151 ret = -EBUSY;
152 goto put_exit;
153 }
154 }
155 } else {
156 ret = mm_iommu_new(container->mm, vaddr, entries, &mem);
157 if (ret)
158 return ret;
159 }
160
161 tcemem = kzalloc(sizeof(*tcemem), GFP_KERNEL);
162 if (!tcemem) {
163 ret = -ENOMEM;
164 goto put_exit;
165 }
166
167 tcemem->mem = mem;
168 list_add(&tcemem->next, &container->prereg_list);
169
170 container->enabled = true;
171
172 return 0;
173
174 put_exit:
175 mm_iommu_put(container->mm, mem);
176 return ret;
177 }
178
tce_page_is_contained(struct mm_struct * mm,unsigned long hpa,unsigned int it_page_shift)179 static bool tce_page_is_contained(struct mm_struct *mm, unsigned long hpa,
180 unsigned int it_page_shift)
181 {
182 struct page *page;
183 unsigned long size = 0;
184
185 if (mm_iommu_is_devmem(mm, hpa, it_page_shift, &size))
186 return size == (1UL << it_page_shift);
187
188 page = pfn_to_page(hpa >> PAGE_SHIFT);
189 /*
190 * Check that the TCE table granularity is not bigger than the size of
191 * a page we just found. Otherwise the hardware can get access to
192 * a bigger memory chunk that it should.
193 */
194 return page_shift(compound_head(page)) >= it_page_shift;
195 }
196
tce_groups_attached(struct tce_container * container)197 static inline bool tce_groups_attached(struct tce_container *container)
198 {
199 return !list_empty(&container->group_list);
200 }
201
tce_iommu_find_table(struct tce_container * container,phys_addr_t ioba,struct iommu_table ** ptbl)202 static long tce_iommu_find_table(struct tce_container *container,
203 phys_addr_t ioba, struct iommu_table **ptbl)
204 {
205 long i;
206
207 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
208 struct iommu_table *tbl = container->tables[i];
209
210 if (tbl) {
211 unsigned long entry = ioba >> tbl->it_page_shift;
212 unsigned long start = tbl->it_offset;
213 unsigned long end = start + tbl->it_size;
214
215 if ((start <= entry) && (entry < end)) {
216 *ptbl = tbl;
217 return i;
218 }
219 }
220 }
221
222 return -1;
223 }
224
tce_iommu_find_free_table(struct tce_container * container)225 static int tce_iommu_find_free_table(struct tce_container *container)
226 {
227 int i;
228
229 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
230 if (!container->tables[i])
231 return i;
232 }
233
234 return -ENOSPC;
235 }
236
tce_iommu_enable(struct tce_container * container)237 static int tce_iommu_enable(struct tce_container *container)
238 {
239 int ret = 0;
240 unsigned long locked;
241 struct iommu_table_group *table_group;
242 struct tce_iommu_group *tcegrp;
243
244 if (container->enabled)
245 return -EBUSY;
246
247 /*
248 * When userspace pages are mapped into the IOMMU, they are effectively
249 * locked memory, so, theoretically, we need to update the accounting
250 * of locked pages on each map and unmap. For powerpc, the map unmap
251 * paths can be very hot, though, and the accounting would kill
252 * performance, especially since it would be difficult to impossible
253 * to handle the accounting in real mode only.
254 *
255 * To address that, rather than precisely accounting every page, we
256 * instead account for a worst case on locked memory when the iommu is
257 * enabled and disabled. The worst case upper bound on locked memory
258 * is the size of the whole iommu window, which is usually relatively
259 * small (compared to total memory sizes) on POWER hardware.
260 *
261 * Also we don't have a nice way to fail on H_PUT_TCE due to ulimits,
262 * that would effectively kill the guest at random points, much better
263 * enforcing the limit based on the max that the guest can map.
264 *
265 * Unfortunately at the moment it counts whole tables, no matter how
266 * much memory the guest has. I.e. for 4GB guest and 4 IOMMU groups
267 * each with 2GB DMA window, 8GB will be counted here. The reason for
268 * this is that we cannot tell here the amount of RAM used by the guest
269 * as this information is only available from KVM and VFIO is
270 * KVM agnostic.
271 *
272 * So we do not allow enabling a container without a group attached
273 * as there is no way to know how much we should increment
274 * the locked_vm counter.
275 */
276 if (!tce_groups_attached(container))
277 return -ENODEV;
278
279 tcegrp = list_first_entry(&container->group_list,
280 struct tce_iommu_group, next);
281 table_group = iommu_group_get_iommudata(tcegrp->grp);
282 if (!table_group)
283 return -ENODEV;
284
285 if (!table_group->tce32_size)
286 return -EPERM;
287
288 ret = tce_iommu_mm_set(container);
289 if (ret)
290 return ret;
291
292 locked = table_group->tce32_size >> PAGE_SHIFT;
293 ret = account_locked_vm(container->mm, locked, true);
294 if (ret)
295 return ret;
296
297 container->locked_pages = locked;
298
299 container->enabled = true;
300
301 return ret;
302 }
303
tce_iommu_disable(struct tce_container * container)304 static void tce_iommu_disable(struct tce_container *container)
305 {
306 if (!container->enabled)
307 return;
308
309 container->enabled = false;
310
311 BUG_ON(!container->mm);
312 account_locked_vm(container->mm, container->locked_pages, false);
313 }
314
tce_iommu_open(unsigned long arg)315 static void *tce_iommu_open(unsigned long arg)
316 {
317 struct tce_container *container;
318
319 if ((arg != VFIO_SPAPR_TCE_IOMMU) && (arg != VFIO_SPAPR_TCE_v2_IOMMU)) {
320 pr_err("tce_vfio: Wrong IOMMU type\n");
321 return ERR_PTR(-EINVAL);
322 }
323
324 container = kzalloc(sizeof(*container), GFP_KERNEL);
325 if (!container)
326 return ERR_PTR(-ENOMEM);
327
328 mutex_init(&container->lock);
329 INIT_LIST_HEAD_RCU(&container->group_list);
330 INIT_LIST_HEAD_RCU(&container->prereg_list);
331
332 container->v2 = arg == VFIO_SPAPR_TCE_v2_IOMMU;
333
334 return container;
335 }
336
337 static int tce_iommu_clear(struct tce_container *container,
338 struct iommu_table *tbl,
339 unsigned long entry, unsigned long pages);
340 static void tce_iommu_free_table(struct tce_container *container,
341 struct iommu_table *tbl);
342
tce_iommu_release(void * iommu_data)343 static void tce_iommu_release(void *iommu_data)
344 {
345 struct tce_container *container = iommu_data;
346 struct tce_iommu_group *tcegrp;
347 struct tce_iommu_prereg *tcemem, *tmtmp;
348 long i;
349
350 while (tce_groups_attached(container)) {
351 tcegrp = list_first_entry(&container->group_list,
352 struct tce_iommu_group, next);
353 tce_iommu_detach_group(iommu_data, tcegrp->grp);
354 }
355
356 /*
357 * If VFIO created a table, it was not disposed
358 * by tce_iommu_detach_group() so do it now.
359 */
360 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
361 struct iommu_table *tbl = container->tables[i];
362
363 if (!tbl)
364 continue;
365
366 tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
367 tce_iommu_free_table(container, tbl);
368 }
369
370 list_for_each_entry_safe(tcemem, tmtmp, &container->prereg_list, next)
371 WARN_ON(tce_iommu_prereg_free(container, tcemem));
372
373 tce_iommu_disable(container);
374 if (container->mm)
375 mmdrop(container->mm);
376 mutex_destroy(&container->lock);
377
378 kfree(container);
379 }
380
tce_iommu_unuse_page(unsigned long hpa)381 static void tce_iommu_unuse_page(unsigned long hpa)
382 {
383 struct page *page;
384
385 page = pfn_to_page(hpa >> PAGE_SHIFT);
386 unpin_user_page(page);
387 }
388
tce_iommu_prereg_ua_to_hpa(struct tce_container * container,unsigned long tce,unsigned long shift,unsigned long * phpa,struct mm_iommu_table_group_mem_t ** pmem)389 static int tce_iommu_prereg_ua_to_hpa(struct tce_container *container,
390 unsigned long tce, unsigned long shift,
391 unsigned long *phpa, struct mm_iommu_table_group_mem_t **pmem)
392 {
393 long ret = 0;
394 struct mm_iommu_table_group_mem_t *mem;
395
396 mem = mm_iommu_lookup(container->mm, tce, 1ULL << shift);
397 if (!mem)
398 return -EINVAL;
399
400 ret = mm_iommu_ua_to_hpa(mem, tce, shift, phpa);
401 if (ret)
402 return -EINVAL;
403
404 *pmem = mem;
405
406 return 0;
407 }
408
tce_iommu_unuse_page_v2(struct tce_container * container,struct iommu_table * tbl,unsigned long entry)409 static void tce_iommu_unuse_page_v2(struct tce_container *container,
410 struct iommu_table *tbl, unsigned long entry)
411 {
412 struct mm_iommu_table_group_mem_t *mem = NULL;
413 int ret;
414 unsigned long hpa = 0;
415 __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl, entry);
416
417 if (!pua)
418 return;
419
420 ret = tce_iommu_prereg_ua_to_hpa(container, be64_to_cpu(*pua),
421 tbl->it_page_shift, &hpa, &mem);
422 if (ret)
423 pr_debug("%s: tce %llx at #%lx was not cached, ret=%d\n",
424 __func__, be64_to_cpu(*pua), entry, ret);
425 if (mem)
426 mm_iommu_mapped_dec(mem);
427
428 *pua = cpu_to_be64(0);
429 }
430
tce_iommu_clear(struct tce_container * container,struct iommu_table * tbl,unsigned long entry,unsigned long pages)431 static int tce_iommu_clear(struct tce_container *container,
432 struct iommu_table *tbl,
433 unsigned long entry, unsigned long pages)
434 {
435 unsigned long oldhpa;
436 long ret;
437 enum dma_data_direction direction;
438 unsigned long lastentry = entry + pages, firstentry = entry;
439
440 for ( ; entry < lastentry; ++entry) {
441 if (tbl->it_indirect_levels && tbl->it_userspace) {
442 /*
443 * For multilevel tables, we can take a shortcut here
444 * and skip some TCEs as we know that the userspace
445 * addresses cache is a mirror of the real TCE table
446 * and if it is missing some indirect levels, then
447 * the hardware table does not have them allocated
448 * either and therefore does not require updating.
449 */
450 __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY_RO(tbl,
451 entry);
452 if (!pua) {
453 /* align to level_size which is power of two */
454 entry |= tbl->it_level_size - 1;
455 continue;
456 }
457 }
458
459 cond_resched();
460
461 direction = DMA_NONE;
462 oldhpa = 0;
463 ret = iommu_tce_xchg_no_kill(container->mm, tbl, entry, &oldhpa,
464 &direction);
465 if (ret)
466 continue;
467
468 if (direction == DMA_NONE)
469 continue;
470
471 if (container->v2) {
472 tce_iommu_unuse_page_v2(container, tbl, entry);
473 continue;
474 }
475
476 tce_iommu_unuse_page(oldhpa);
477 }
478
479 iommu_tce_kill(tbl, firstentry, pages);
480
481 return 0;
482 }
483
tce_iommu_use_page(unsigned long tce,unsigned long * hpa)484 static int tce_iommu_use_page(unsigned long tce, unsigned long *hpa)
485 {
486 struct page *page = NULL;
487 enum dma_data_direction direction = iommu_tce_direction(tce);
488
489 if (pin_user_pages_fast(tce & PAGE_MASK, 1,
490 direction != DMA_TO_DEVICE ? FOLL_WRITE : 0,
491 &page) != 1)
492 return -EFAULT;
493
494 *hpa = __pa((unsigned long) page_address(page));
495
496 return 0;
497 }
498
tce_iommu_build(struct tce_container * container,struct iommu_table * tbl,unsigned long entry,unsigned long tce,unsigned long pages,enum dma_data_direction direction)499 static long tce_iommu_build(struct tce_container *container,
500 struct iommu_table *tbl,
501 unsigned long entry, unsigned long tce, unsigned long pages,
502 enum dma_data_direction direction)
503 {
504 long i, ret = 0;
505 unsigned long hpa;
506 enum dma_data_direction dirtmp;
507
508 for (i = 0; i < pages; ++i) {
509 unsigned long offset = tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK;
510
511 ret = tce_iommu_use_page(tce, &hpa);
512 if (ret)
513 break;
514
515 if (!tce_page_is_contained(container->mm, hpa,
516 tbl->it_page_shift)) {
517 ret = -EPERM;
518 break;
519 }
520
521 hpa |= offset;
522 dirtmp = direction;
523 ret = iommu_tce_xchg_no_kill(container->mm, tbl, entry + i,
524 &hpa, &dirtmp);
525 if (ret) {
526 tce_iommu_unuse_page(hpa);
527 pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n",
528 __func__, entry << tbl->it_page_shift,
529 tce, ret);
530 break;
531 }
532
533 if (dirtmp != DMA_NONE)
534 tce_iommu_unuse_page(hpa);
535
536 tce += IOMMU_PAGE_SIZE(tbl);
537 }
538
539 if (ret)
540 tce_iommu_clear(container, tbl, entry, i);
541 else
542 iommu_tce_kill(tbl, entry, pages);
543
544 return ret;
545 }
546
tce_iommu_build_v2(struct tce_container * container,struct iommu_table * tbl,unsigned long entry,unsigned long tce,unsigned long pages,enum dma_data_direction direction)547 static long tce_iommu_build_v2(struct tce_container *container,
548 struct iommu_table *tbl,
549 unsigned long entry, unsigned long tce, unsigned long pages,
550 enum dma_data_direction direction)
551 {
552 long i, ret = 0;
553 unsigned long hpa;
554 enum dma_data_direction dirtmp;
555
556 for (i = 0; i < pages; ++i) {
557 struct mm_iommu_table_group_mem_t *mem = NULL;
558 __be64 *pua = IOMMU_TABLE_USERSPACE_ENTRY(tbl, entry + i);
559
560 ret = tce_iommu_prereg_ua_to_hpa(container,
561 tce, tbl->it_page_shift, &hpa, &mem);
562 if (ret)
563 break;
564
565 if (!tce_page_is_contained(container->mm, hpa,
566 tbl->it_page_shift)) {
567 ret = -EPERM;
568 break;
569 }
570
571 /* Preserve offset within IOMMU page */
572 hpa |= tce & IOMMU_PAGE_MASK(tbl) & ~PAGE_MASK;
573 dirtmp = direction;
574
575 /* The registered region is being unregistered */
576 if (mm_iommu_mapped_inc(mem))
577 break;
578
579 ret = iommu_tce_xchg_no_kill(container->mm, tbl, entry + i,
580 &hpa, &dirtmp);
581 if (ret) {
582 /* dirtmp cannot be DMA_NONE here */
583 tce_iommu_unuse_page_v2(container, tbl, entry + i);
584 pr_err("iommu_tce: %s failed ioba=%lx, tce=%lx, ret=%ld\n",
585 __func__, entry << tbl->it_page_shift,
586 tce, ret);
587 break;
588 }
589
590 if (dirtmp != DMA_NONE)
591 tce_iommu_unuse_page_v2(container, tbl, entry + i);
592
593 *pua = cpu_to_be64(tce);
594
595 tce += IOMMU_PAGE_SIZE(tbl);
596 }
597
598 if (ret)
599 tce_iommu_clear(container, tbl, entry, i);
600 else
601 iommu_tce_kill(tbl, entry, pages);
602
603 return ret;
604 }
605
tce_iommu_create_table(struct tce_container * container,struct iommu_table_group * table_group,int num,__u32 page_shift,__u64 window_size,__u32 levels,struct iommu_table ** ptbl)606 static long tce_iommu_create_table(struct tce_container *container,
607 struct iommu_table_group *table_group,
608 int num,
609 __u32 page_shift,
610 __u64 window_size,
611 __u32 levels,
612 struct iommu_table **ptbl)
613 {
614 long ret, table_size;
615
616 table_size = table_group->ops->get_table_size(page_shift, window_size,
617 levels);
618 if (!table_size)
619 return -EINVAL;
620
621 ret = account_locked_vm(container->mm, table_size >> PAGE_SHIFT, true);
622 if (ret)
623 return ret;
624
625 ret = table_group->ops->create_table(table_group, num,
626 page_shift, window_size, levels, ptbl);
627
628 WARN_ON(!ret && !(*ptbl)->it_ops->free);
629 WARN_ON(!ret && ((*ptbl)->it_allocated_size > table_size));
630
631 return ret;
632 }
633
tce_iommu_free_table(struct tce_container * container,struct iommu_table * tbl)634 static void tce_iommu_free_table(struct tce_container *container,
635 struct iommu_table *tbl)
636 {
637 unsigned long pages = tbl->it_allocated_size >> PAGE_SHIFT;
638
639 iommu_tce_table_put(tbl);
640 account_locked_vm(container->mm, pages, false);
641 }
642
tce_iommu_create_window(struct tce_container * container,__u32 page_shift,__u64 window_size,__u32 levels,__u64 * start_addr)643 static long tce_iommu_create_window(struct tce_container *container,
644 __u32 page_shift, __u64 window_size, __u32 levels,
645 __u64 *start_addr)
646 {
647 struct tce_iommu_group *tcegrp;
648 struct iommu_table_group *table_group;
649 struct iommu_table *tbl = NULL;
650 long ret, num;
651
652 num = tce_iommu_find_free_table(container);
653 if (num < 0)
654 return num;
655
656 /* Get the first group for ops::create_table */
657 tcegrp = list_first_entry(&container->group_list,
658 struct tce_iommu_group, next);
659 table_group = iommu_group_get_iommudata(tcegrp->grp);
660 if (!table_group)
661 return -EFAULT;
662
663 if (!(table_group->pgsizes & (1ULL << page_shift)))
664 return -EINVAL;
665
666 if (!table_group->ops->set_window || !table_group->ops->unset_window ||
667 !table_group->ops->get_table_size ||
668 !table_group->ops->create_table)
669 return -EPERM;
670
671 /* Create TCE table */
672 ret = tce_iommu_create_table(container, table_group, num,
673 page_shift, window_size, levels, &tbl);
674 if (ret)
675 return ret;
676
677 BUG_ON(!tbl->it_ops->free);
678
679 /*
680 * Program the table to every group.
681 * Groups have been tested for compatibility at the attach time.
682 */
683 list_for_each_entry(tcegrp, &container->group_list, next) {
684 table_group = iommu_group_get_iommudata(tcegrp->grp);
685
686 ret = table_group->ops->set_window(table_group, num, tbl);
687 if (ret)
688 goto unset_exit;
689 }
690
691 container->tables[num] = tbl;
692
693 /* Return start address assigned by platform in create_table() */
694 *start_addr = tbl->it_offset << tbl->it_page_shift;
695
696 return 0;
697
698 unset_exit:
699 list_for_each_entry(tcegrp, &container->group_list, next) {
700 table_group = iommu_group_get_iommudata(tcegrp->grp);
701 table_group->ops->unset_window(table_group, num);
702 }
703 tce_iommu_free_table(container, tbl);
704
705 return ret;
706 }
707
tce_iommu_remove_window(struct tce_container * container,__u64 start_addr)708 static long tce_iommu_remove_window(struct tce_container *container,
709 __u64 start_addr)
710 {
711 struct iommu_table_group *table_group = NULL;
712 struct iommu_table *tbl;
713 struct tce_iommu_group *tcegrp;
714 int num;
715
716 num = tce_iommu_find_table(container, start_addr, &tbl);
717 if (num < 0)
718 return -EINVAL;
719
720 BUG_ON(!tbl->it_size);
721
722 /* Detach groups from IOMMUs */
723 list_for_each_entry(tcegrp, &container->group_list, next) {
724 table_group = iommu_group_get_iommudata(tcegrp->grp);
725
726 /*
727 * SPAPR TCE IOMMU exposes the default DMA window to
728 * the guest via dma32_window_start/size of
729 * VFIO_IOMMU_SPAPR_TCE_GET_INFO. Some platforms allow
730 * the userspace to remove this window, some do not so
731 * here we check for the platform capability.
732 */
733 if (!table_group->ops || !table_group->ops->unset_window)
734 return -EPERM;
735
736 table_group->ops->unset_window(table_group, num);
737 }
738
739 /* Free table */
740 tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
741 tce_iommu_free_table(container, tbl);
742 container->tables[num] = NULL;
743
744 return 0;
745 }
746
tce_iommu_create_default_window(struct tce_container * container)747 static long tce_iommu_create_default_window(struct tce_container *container)
748 {
749 long ret;
750 __u64 start_addr = 0;
751 struct tce_iommu_group *tcegrp;
752 struct iommu_table_group *table_group;
753
754 if (!container->def_window_pending)
755 return 0;
756
757 if (!tce_groups_attached(container))
758 return -ENODEV;
759
760 tcegrp = list_first_entry(&container->group_list,
761 struct tce_iommu_group, next);
762 table_group = iommu_group_get_iommudata(tcegrp->grp);
763 if (!table_group)
764 return -ENODEV;
765
766 ret = tce_iommu_create_window(container, IOMMU_PAGE_SHIFT_4K,
767 table_group->tce32_size, 1, &start_addr);
768 WARN_ON_ONCE(!ret && start_addr);
769
770 if (!ret)
771 container->def_window_pending = false;
772
773 return ret;
774 }
775
tce_iommu_ioctl(void * iommu_data,unsigned int cmd,unsigned long arg)776 static long tce_iommu_ioctl(void *iommu_data,
777 unsigned int cmd, unsigned long arg)
778 {
779 struct tce_container *container = iommu_data;
780 unsigned long minsz, ddwsz;
781 long ret;
782
783 switch (cmd) {
784 case VFIO_CHECK_EXTENSION:
785 switch (arg) {
786 case VFIO_SPAPR_TCE_IOMMU:
787 case VFIO_SPAPR_TCE_v2_IOMMU:
788 ret = 1;
789 break;
790 default:
791 ret = vfio_spapr_iommu_eeh_ioctl(NULL, cmd, arg);
792 break;
793 }
794
795 return (ret < 0) ? 0 : ret;
796 }
797
798 /*
799 * Sanity check to prevent one userspace from manipulating
800 * another userspace mm.
801 */
802 BUG_ON(!container);
803 if (container->mm && container->mm != current->mm)
804 return -EPERM;
805
806 switch (cmd) {
807 case VFIO_IOMMU_SPAPR_TCE_GET_INFO: {
808 struct vfio_iommu_spapr_tce_info info;
809 struct tce_iommu_group *tcegrp;
810 struct iommu_table_group *table_group;
811
812 if (!tce_groups_attached(container))
813 return -ENXIO;
814
815 tcegrp = list_first_entry(&container->group_list,
816 struct tce_iommu_group, next);
817 table_group = iommu_group_get_iommudata(tcegrp->grp);
818
819 if (!table_group)
820 return -ENXIO;
821
822 minsz = offsetofend(struct vfio_iommu_spapr_tce_info,
823 dma32_window_size);
824
825 if (copy_from_user(&info, (void __user *)arg, minsz))
826 return -EFAULT;
827
828 if (info.argsz < minsz)
829 return -EINVAL;
830
831 info.dma32_window_start = table_group->tce32_start;
832 info.dma32_window_size = table_group->tce32_size;
833 info.flags = 0;
834 memset(&info.ddw, 0, sizeof(info.ddw));
835
836 if (table_group->max_dynamic_windows_supported &&
837 container->v2) {
838 info.flags |= VFIO_IOMMU_SPAPR_INFO_DDW;
839 info.ddw.pgsizes = table_group->pgsizes;
840 info.ddw.max_dynamic_windows_supported =
841 table_group->max_dynamic_windows_supported;
842 info.ddw.levels = table_group->max_levels;
843 }
844
845 ddwsz = offsetofend(struct vfio_iommu_spapr_tce_info, ddw);
846
847 if (info.argsz >= ddwsz)
848 minsz = ddwsz;
849
850 if (copy_to_user((void __user *)arg, &info, minsz))
851 return -EFAULT;
852
853 return 0;
854 }
855 case VFIO_IOMMU_MAP_DMA: {
856 struct vfio_iommu_type1_dma_map param;
857 struct iommu_table *tbl = NULL;
858 long num;
859 enum dma_data_direction direction;
860
861 if (!container->enabled)
862 return -EPERM;
863
864 minsz = offsetofend(struct vfio_iommu_type1_dma_map, size);
865
866 if (copy_from_user(¶m, (void __user *)arg, minsz))
867 return -EFAULT;
868
869 if (param.argsz < minsz)
870 return -EINVAL;
871
872 if (param.flags & ~(VFIO_DMA_MAP_FLAG_READ |
873 VFIO_DMA_MAP_FLAG_WRITE))
874 return -EINVAL;
875
876 ret = tce_iommu_create_default_window(container);
877 if (ret)
878 return ret;
879
880 num = tce_iommu_find_table(container, param.iova, &tbl);
881 if (num < 0)
882 return -ENXIO;
883
884 if ((param.size & ~IOMMU_PAGE_MASK(tbl)) ||
885 (param.vaddr & ~IOMMU_PAGE_MASK(tbl)))
886 return -EINVAL;
887
888 /* iova is checked by the IOMMU API */
889 if (param.flags & VFIO_DMA_MAP_FLAG_READ) {
890 if (param.flags & VFIO_DMA_MAP_FLAG_WRITE)
891 direction = DMA_BIDIRECTIONAL;
892 else
893 direction = DMA_TO_DEVICE;
894 } else {
895 if (param.flags & VFIO_DMA_MAP_FLAG_WRITE)
896 direction = DMA_FROM_DEVICE;
897 else
898 return -EINVAL;
899 }
900
901 ret = iommu_tce_put_param_check(tbl, param.iova, param.vaddr);
902 if (ret)
903 return ret;
904
905 if (container->v2)
906 ret = tce_iommu_build_v2(container, tbl,
907 param.iova >> tbl->it_page_shift,
908 param.vaddr,
909 param.size >> tbl->it_page_shift,
910 direction);
911 else
912 ret = tce_iommu_build(container, tbl,
913 param.iova >> tbl->it_page_shift,
914 param.vaddr,
915 param.size >> tbl->it_page_shift,
916 direction);
917
918 iommu_flush_tce(tbl);
919
920 return ret;
921 }
922 case VFIO_IOMMU_UNMAP_DMA: {
923 struct vfio_iommu_type1_dma_unmap param;
924 struct iommu_table *tbl = NULL;
925 long num;
926
927 if (!container->enabled)
928 return -EPERM;
929
930 minsz = offsetofend(struct vfio_iommu_type1_dma_unmap,
931 size);
932
933 if (copy_from_user(¶m, (void __user *)arg, minsz))
934 return -EFAULT;
935
936 if (param.argsz < minsz)
937 return -EINVAL;
938
939 /* No flag is supported now */
940 if (param.flags)
941 return -EINVAL;
942
943 ret = tce_iommu_create_default_window(container);
944 if (ret)
945 return ret;
946
947 num = tce_iommu_find_table(container, param.iova, &tbl);
948 if (num < 0)
949 return -ENXIO;
950
951 if (param.size & ~IOMMU_PAGE_MASK(tbl))
952 return -EINVAL;
953
954 ret = iommu_tce_clear_param_check(tbl, param.iova, 0,
955 param.size >> tbl->it_page_shift);
956 if (ret)
957 return ret;
958
959 ret = tce_iommu_clear(container, tbl,
960 param.iova >> tbl->it_page_shift,
961 param.size >> tbl->it_page_shift);
962 iommu_flush_tce(tbl);
963
964 return ret;
965 }
966 case VFIO_IOMMU_SPAPR_REGISTER_MEMORY: {
967 struct vfio_iommu_spapr_register_memory param;
968
969 if (!container->v2)
970 break;
971
972 minsz = offsetofend(struct vfio_iommu_spapr_register_memory,
973 size);
974
975 ret = tce_iommu_mm_set(container);
976 if (ret)
977 return ret;
978
979 if (copy_from_user(¶m, (void __user *)arg, minsz))
980 return -EFAULT;
981
982 if (param.argsz < minsz)
983 return -EINVAL;
984
985 /* No flag is supported now */
986 if (param.flags)
987 return -EINVAL;
988
989 mutex_lock(&container->lock);
990 ret = tce_iommu_register_pages(container, param.vaddr,
991 param.size);
992 mutex_unlock(&container->lock);
993
994 return ret;
995 }
996 case VFIO_IOMMU_SPAPR_UNREGISTER_MEMORY: {
997 struct vfio_iommu_spapr_register_memory param;
998
999 if (!container->v2)
1000 break;
1001
1002 if (!container->mm)
1003 return -EPERM;
1004
1005 minsz = offsetofend(struct vfio_iommu_spapr_register_memory,
1006 size);
1007
1008 if (copy_from_user(¶m, (void __user *)arg, minsz))
1009 return -EFAULT;
1010
1011 if (param.argsz < minsz)
1012 return -EINVAL;
1013
1014 /* No flag is supported now */
1015 if (param.flags)
1016 return -EINVAL;
1017
1018 mutex_lock(&container->lock);
1019 ret = tce_iommu_unregister_pages(container, param.vaddr,
1020 param.size);
1021 mutex_unlock(&container->lock);
1022
1023 return ret;
1024 }
1025 case VFIO_IOMMU_ENABLE:
1026 if (container->v2)
1027 break;
1028
1029 mutex_lock(&container->lock);
1030 ret = tce_iommu_enable(container);
1031 mutex_unlock(&container->lock);
1032 return ret;
1033
1034
1035 case VFIO_IOMMU_DISABLE:
1036 if (container->v2)
1037 break;
1038
1039 mutex_lock(&container->lock);
1040 tce_iommu_disable(container);
1041 mutex_unlock(&container->lock);
1042 return 0;
1043
1044 case VFIO_EEH_PE_OP: {
1045 struct tce_iommu_group *tcegrp;
1046
1047 ret = 0;
1048 list_for_each_entry(tcegrp, &container->group_list, next) {
1049 ret = vfio_spapr_iommu_eeh_ioctl(tcegrp->grp,
1050 cmd, arg);
1051 if (ret)
1052 return ret;
1053 }
1054 return ret;
1055 }
1056
1057 case VFIO_IOMMU_SPAPR_TCE_CREATE: {
1058 struct vfio_iommu_spapr_tce_create create;
1059
1060 if (!container->v2)
1061 break;
1062
1063 ret = tce_iommu_mm_set(container);
1064 if (ret)
1065 return ret;
1066
1067 if (!tce_groups_attached(container))
1068 return -ENXIO;
1069
1070 minsz = offsetofend(struct vfio_iommu_spapr_tce_create,
1071 start_addr);
1072
1073 if (copy_from_user(&create, (void __user *)arg, minsz))
1074 return -EFAULT;
1075
1076 if (create.argsz < minsz)
1077 return -EINVAL;
1078
1079 if (create.flags)
1080 return -EINVAL;
1081
1082 mutex_lock(&container->lock);
1083
1084 ret = tce_iommu_create_default_window(container);
1085 if (!ret)
1086 ret = tce_iommu_create_window(container,
1087 create.page_shift,
1088 create.window_size, create.levels,
1089 &create.start_addr);
1090
1091 mutex_unlock(&container->lock);
1092
1093 if (!ret && copy_to_user((void __user *)arg, &create, minsz))
1094 ret = -EFAULT;
1095
1096 return ret;
1097 }
1098 case VFIO_IOMMU_SPAPR_TCE_REMOVE: {
1099 struct vfio_iommu_spapr_tce_remove remove;
1100
1101 if (!container->v2)
1102 break;
1103
1104 ret = tce_iommu_mm_set(container);
1105 if (ret)
1106 return ret;
1107
1108 if (!tce_groups_attached(container))
1109 return -ENXIO;
1110
1111 minsz = offsetofend(struct vfio_iommu_spapr_tce_remove,
1112 start_addr);
1113
1114 if (copy_from_user(&remove, (void __user *)arg, minsz))
1115 return -EFAULT;
1116
1117 if (remove.argsz < minsz)
1118 return -EINVAL;
1119
1120 if (remove.flags)
1121 return -EINVAL;
1122
1123 if (container->def_window_pending && !remove.start_addr) {
1124 container->def_window_pending = false;
1125 return 0;
1126 }
1127
1128 mutex_lock(&container->lock);
1129
1130 ret = tce_iommu_remove_window(container, remove.start_addr);
1131
1132 mutex_unlock(&container->lock);
1133
1134 return ret;
1135 }
1136 }
1137
1138 return -ENOTTY;
1139 }
1140
tce_iommu_release_ownership(struct tce_container * container,struct iommu_table_group * table_group)1141 static void tce_iommu_release_ownership(struct tce_container *container,
1142 struct iommu_table_group *table_group)
1143 {
1144 int i;
1145
1146 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1147 struct iommu_table *tbl = container->tables[i];
1148
1149 if (!tbl)
1150 continue;
1151
1152 tce_iommu_clear(container, tbl, tbl->it_offset, tbl->it_size);
1153 if (tbl->it_map)
1154 iommu_release_ownership(tbl);
1155
1156 container->tables[i] = NULL;
1157 }
1158 }
1159
tce_iommu_take_ownership(struct tce_container * container,struct iommu_table_group * table_group)1160 static int tce_iommu_take_ownership(struct tce_container *container,
1161 struct iommu_table_group *table_group)
1162 {
1163 int i, j, rc = 0;
1164
1165 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1166 struct iommu_table *tbl = table_group->tables[i];
1167
1168 if (!tbl || !tbl->it_map)
1169 continue;
1170
1171 rc = iommu_take_ownership(tbl);
1172 if (rc) {
1173 for (j = 0; j < i; ++j)
1174 iommu_release_ownership(
1175 table_group->tables[j]);
1176
1177 return rc;
1178 }
1179 }
1180
1181 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
1182 container->tables[i] = table_group->tables[i];
1183
1184 return 0;
1185 }
1186
tce_iommu_release_ownership_ddw(struct tce_container * container,struct iommu_table_group * table_group)1187 static void tce_iommu_release_ownership_ddw(struct tce_container *container,
1188 struct iommu_table_group *table_group)
1189 {
1190 long i;
1191
1192 if (!table_group->ops->unset_window) {
1193 WARN_ON_ONCE(1);
1194 return;
1195 }
1196
1197 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
1198 if (container->tables[i])
1199 table_group->ops->unset_window(table_group, i);
1200
1201 table_group->ops->release_ownership(table_group);
1202 }
1203
tce_iommu_take_ownership_ddw(struct tce_container * container,struct iommu_table_group * table_group)1204 static long tce_iommu_take_ownership_ddw(struct tce_container *container,
1205 struct iommu_table_group *table_group)
1206 {
1207 long i, ret = 0;
1208
1209 if (!table_group->ops->create_table || !table_group->ops->set_window ||
1210 !table_group->ops->release_ownership) {
1211 WARN_ON_ONCE(1);
1212 return -EFAULT;
1213 }
1214
1215 table_group->ops->take_ownership(table_group);
1216
1217 /* Set all windows to the new group */
1218 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i) {
1219 struct iommu_table *tbl = container->tables[i];
1220
1221 if (!tbl)
1222 continue;
1223
1224 ret = table_group->ops->set_window(table_group, i, tbl);
1225 if (ret)
1226 goto release_exit;
1227 }
1228
1229 return 0;
1230
1231 release_exit:
1232 for (i = 0; i < IOMMU_TABLE_GROUP_MAX_TABLES; ++i)
1233 table_group->ops->unset_window(table_group, i);
1234
1235 table_group->ops->release_ownership(table_group);
1236
1237 return ret;
1238 }
1239
tce_iommu_attach_group(void * iommu_data,struct iommu_group * iommu_group,enum vfio_group_type type)1240 static int tce_iommu_attach_group(void *iommu_data,
1241 struct iommu_group *iommu_group, enum vfio_group_type type)
1242 {
1243 int ret = 0;
1244 struct tce_container *container = iommu_data;
1245 struct iommu_table_group *table_group;
1246 struct tce_iommu_group *tcegrp = NULL;
1247
1248 if (type == VFIO_EMULATED_IOMMU)
1249 return -EINVAL;
1250
1251 mutex_lock(&container->lock);
1252
1253 /* pr_debug("tce_vfio: Attaching group #%u to iommu %p\n",
1254 iommu_group_id(iommu_group), iommu_group); */
1255 table_group = iommu_group_get_iommudata(iommu_group);
1256 if (!table_group) {
1257 ret = -ENODEV;
1258 goto unlock_exit;
1259 }
1260
1261 if (tce_groups_attached(container) && (!table_group->ops ||
1262 !table_group->ops->take_ownership ||
1263 !table_group->ops->release_ownership)) {
1264 ret = -EBUSY;
1265 goto unlock_exit;
1266 }
1267
1268 /*
1269 * Check if new group has the same iommu_table_group_ops
1270 * (i.e. compatible)
1271 */
1272 list_for_each_entry(tcegrp, &container->group_list, next) {
1273 struct iommu_table_group *table_group_tmp;
1274
1275 if (tcegrp->grp == iommu_group) {
1276 pr_warn("tce_vfio: Group %d is already attached\n",
1277 iommu_group_id(iommu_group));
1278 ret = -EBUSY;
1279 goto unlock_exit;
1280 }
1281 table_group_tmp = iommu_group_get_iommudata(tcegrp->grp);
1282 if (table_group_tmp->ops->create_table !=
1283 table_group->ops->create_table) {
1284 pr_warn("tce_vfio: Group %d is incompatible with group %d\n",
1285 iommu_group_id(iommu_group),
1286 iommu_group_id(tcegrp->grp));
1287 ret = -EPERM;
1288 goto unlock_exit;
1289 }
1290 }
1291
1292 tcegrp = kzalloc(sizeof(*tcegrp), GFP_KERNEL);
1293 if (!tcegrp) {
1294 ret = -ENOMEM;
1295 goto unlock_exit;
1296 }
1297
1298 if (!table_group->ops || !table_group->ops->take_ownership ||
1299 !table_group->ops->release_ownership) {
1300 if (container->v2) {
1301 ret = -EPERM;
1302 goto free_exit;
1303 }
1304 ret = tce_iommu_take_ownership(container, table_group);
1305 } else {
1306 if (!container->v2) {
1307 ret = -EPERM;
1308 goto free_exit;
1309 }
1310 ret = tce_iommu_take_ownership_ddw(container, table_group);
1311 if (!tce_groups_attached(container) && !container->tables[0])
1312 container->def_window_pending = true;
1313 }
1314
1315 if (!ret) {
1316 tcegrp->grp = iommu_group;
1317 list_add(&tcegrp->next, &container->group_list);
1318 }
1319
1320 free_exit:
1321 if (ret && tcegrp)
1322 kfree(tcegrp);
1323
1324 unlock_exit:
1325 mutex_unlock(&container->lock);
1326
1327 return ret;
1328 }
1329
tce_iommu_detach_group(void * iommu_data,struct iommu_group * iommu_group)1330 static void tce_iommu_detach_group(void *iommu_data,
1331 struct iommu_group *iommu_group)
1332 {
1333 struct tce_container *container = iommu_data;
1334 struct iommu_table_group *table_group;
1335 bool found = false;
1336 struct tce_iommu_group *tcegrp;
1337
1338 mutex_lock(&container->lock);
1339
1340 list_for_each_entry(tcegrp, &container->group_list, next) {
1341 if (tcegrp->grp == iommu_group) {
1342 found = true;
1343 break;
1344 }
1345 }
1346
1347 if (!found) {
1348 pr_warn("tce_vfio: detaching unattached group #%u\n",
1349 iommu_group_id(iommu_group));
1350 goto unlock_exit;
1351 }
1352
1353 list_del(&tcegrp->next);
1354 kfree(tcegrp);
1355
1356 table_group = iommu_group_get_iommudata(iommu_group);
1357 BUG_ON(!table_group);
1358
1359 if (!table_group->ops || !table_group->ops->release_ownership)
1360 tce_iommu_release_ownership(container, table_group);
1361 else
1362 tce_iommu_release_ownership_ddw(container, table_group);
1363
1364 unlock_exit:
1365 mutex_unlock(&container->lock);
1366 }
1367
1368 static const struct vfio_iommu_driver_ops tce_iommu_driver_ops = {
1369 .name = "iommu-vfio-powerpc",
1370 .owner = THIS_MODULE,
1371 .open = tce_iommu_open,
1372 .release = tce_iommu_release,
1373 .ioctl = tce_iommu_ioctl,
1374 .attach_group = tce_iommu_attach_group,
1375 .detach_group = tce_iommu_detach_group,
1376 };
1377
tce_iommu_init(void)1378 static int __init tce_iommu_init(void)
1379 {
1380 return vfio_register_iommu_driver(&tce_iommu_driver_ops);
1381 }
1382
tce_iommu_cleanup(void)1383 static void __exit tce_iommu_cleanup(void)
1384 {
1385 vfio_unregister_iommu_driver(&tce_iommu_driver_ops);
1386 }
1387
1388 module_init(tce_iommu_init);
1389 module_exit(tce_iommu_cleanup);
1390
1391 MODULE_VERSION(DRIVER_VERSION);
1392 MODULE_LICENSE("GPL v2");
1393 MODULE_AUTHOR(DRIVER_AUTHOR);
1394 MODULE_DESCRIPTION(DRIVER_DESC);
1395
1396