1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * VFIO: IOMMU DMA mapping support for Type1 IOMMU
4  *
5  * Copyright (C) 2012 Red Hat, Inc.  All rights reserved.
6  *     Author: Alex Williamson <alex.williamson@redhat.com>
7  *
8  * Derived from original vfio:
9  * Copyright 2010 Cisco Systems, Inc.  All rights reserved.
10  * Author: Tom Lyon, pugs@cisco.com
11  *
12  * We arbitrarily define a Type1 IOMMU as one matching the below code.
13  * It could be called the x86 IOMMU as it's designed for AMD-Vi & Intel
14  * VT-d, but that makes it harder to re-use as theoretically anyone
15  * implementing a similar IOMMU could make use of this.  We expect the
16  * IOMMU to support the IOMMU API and have few to no restrictions around
17  * the IOVA range that can be mapped.  The Type1 IOMMU is currently
18  * optimized for relatively static mappings of a userspace process with
19  * userspace pages pinned into memory.  We also assume devices and IOMMU
20  * domains are PCI based as the IOMMU API is still centered around a
21  * device/bus interface rather than a group interface.
22  */
23 
24 #include <linux/compat.h>
25 #include <linux/device.h>
26 #include <linux/fs.h>
27 #include <linux/highmem.h>
28 #include <linux/iommu.h>
29 #include <linux/module.h>
30 #include <linux/mm.h>
31 #include <linux/kthread.h>
32 #include <linux/rbtree.h>
33 #include <linux/sched/signal.h>
34 #include <linux/sched/mm.h>
35 #include <linux/slab.h>
36 #include <linux/uaccess.h>
37 #include <linux/vfio.h>
38 #include <linux/workqueue.h>
39 #include <linux/notifier.h>
40 #include <linux/dma-iommu.h>
41 #include <linux/irqdomain.h>
42 #include "vfio.h"
43 
44 #define DRIVER_VERSION  "0.2"
45 #define DRIVER_AUTHOR   "Alex Williamson <alex.williamson@redhat.com>"
46 #define DRIVER_DESC     "Type1 IOMMU driver for VFIO"
47 
48 static bool allow_unsafe_interrupts;
49 module_param_named(allow_unsafe_interrupts,
50 		   allow_unsafe_interrupts, bool, S_IRUGO | S_IWUSR);
51 MODULE_PARM_DESC(allow_unsafe_interrupts,
52 		 "Enable VFIO IOMMU support for on platforms without interrupt remapping support.");
53 
54 static bool disable_hugepages;
55 module_param_named(disable_hugepages,
56 		   disable_hugepages, bool, S_IRUGO | S_IWUSR);
57 MODULE_PARM_DESC(disable_hugepages,
58 		 "Disable VFIO IOMMU support for IOMMU hugepages.");
59 
60 static unsigned int dma_entry_limit __read_mostly = U16_MAX;
61 module_param_named(dma_entry_limit, dma_entry_limit, uint, 0644);
62 MODULE_PARM_DESC(dma_entry_limit,
63 		 "Maximum number of user DMA mappings per container (65535).");
64 
65 struct vfio_iommu {
66 	struct list_head	domain_list;
67 	struct list_head	iova_list;
68 	struct mutex		lock;
69 	struct rb_root		dma_list;
70 	struct list_head	device_list;
71 	struct mutex		device_list_lock;
72 	unsigned int		dma_avail;
73 	unsigned int		vaddr_invalid_count;
74 	uint64_t		pgsize_bitmap;
75 	uint64_t		num_non_pinned_groups;
76 	wait_queue_head_t	vaddr_wait;
77 	bool			v2;
78 	bool			nesting;
79 	bool			dirty_page_tracking;
80 	bool			container_open;
81 	struct list_head	emulated_iommu_groups;
82 };
83 
84 struct vfio_domain {
85 	struct iommu_domain	*domain;
86 	struct list_head	next;
87 	struct list_head	group_list;
88 	bool			fgsp : 1;	/* Fine-grained super pages */
89 	bool			enforce_cache_coherency : 1;
90 };
91 
92 struct vfio_dma {
93 	struct rb_node		node;
94 	dma_addr_t		iova;		/* Device address */
95 	unsigned long		vaddr;		/* Process virtual addr */
96 	size_t			size;		/* Map size (bytes) */
97 	int			prot;		/* IOMMU_READ/WRITE */
98 	bool			iommu_mapped;
99 	bool			lock_cap;	/* capable(CAP_IPC_LOCK) */
100 	bool			vaddr_invalid;
101 	struct task_struct	*task;
102 	struct rb_root		pfn_list;	/* Ex-user pinned pfn list */
103 	unsigned long		*bitmap;
104 };
105 
106 struct vfio_batch {
107 	struct page		**pages;	/* for pin_user_pages_remote */
108 	struct page		*fallback_page; /* if pages alloc fails */
109 	int			capacity;	/* length of pages array */
110 	int			size;		/* of batch currently */
111 	int			offset;		/* of next entry in pages */
112 };
113 
114 struct vfio_iommu_group {
115 	struct iommu_group	*iommu_group;
116 	struct list_head	next;
117 	bool			pinned_page_dirty_scope;
118 };
119 
120 struct vfio_iova {
121 	struct list_head	list;
122 	dma_addr_t		start;
123 	dma_addr_t		end;
124 };
125 
126 /*
127  * Guest RAM pinning working set or DMA target
128  */
129 struct vfio_pfn {
130 	struct rb_node		node;
131 	dma_addr_t		iova;		/* Device address */
132 	unsigned long		pfn;		/* Host pfn */
133 	unsigned int		ref_count;
134 };
135 
136 struct vfio_regions {
137 	struct list_head list;
138 	dma_addr_t iova;
139 	phys_addr_t phys;
140 	size_t len;
141 };
142 
143 #define DIRTY_BITMAP_BYTES(n)	(ALIGN(n, BITS_PER_TYPE(u64)) / BITS_PER_BYTE)
144 
145 /*
146  * Input argument of number of bits to bitmap_set() is unsigned integer, which
147  * further casts to signed integer for unaligned multi-bit operation,
148  * __bitmap_set().
149  * Then maximum bitmap size supported is 2^31 bits divided by 2^3 bits/byte,
150  * that is 2^28 (256 MB) which maps to 2^31 * 2^12 = 2^43 (8TB) on 4K page
151  * system.
152  */
153 #define DIRTY_BITMAP_PAGES_MAX	 ((u64)INT_MAX)
154 #define DIRTY_BITMAP_SIZE_MAX	 DIRTY_BITMAP_BYTES(DIRTY_BITMAP_PAGES_MAX)
155 
156 #define WAITED 1
157 
158 static int put_pfn(unsigned long pfn, int prot);
159 
160 static struct vfio_iommu_group*
161 vfio_iommu_find_iommu_group(struct vfio_iommu *iommu,
162 			    struct iommu_group *iommu_group);
163 
164 /*
165  * This code handles mapping and unmapping of user data buffers
166  * into DMA'ble space using the IOMMU
167  */
168 
169 static struct vfio_dma *vfio_find_dma(struct vfio_iommu *iommu,
170 				      dma_addr_t start, size_t size)
171 {
172 	struct rb_node *node = iommu->dma_list.rb_node;
173 
174 	while (node) {
175 		struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node);
176 
177 		if (start + size <= dma->iova)
178 			node = node->rb_left;
179 		else if (start >= dma->iova + dma->size)
180 			node = node->rb_right;
181 		else
182 			return dma;
183 	}
184 
185 	return NULL;
186 }
187 
188 static struct rb_node *vfio_find_dma_first_node(struct vfio_iommu *iommu,
189 						dma_addr_t start, u64 size)
190 {
191 	struct rb_node *res = NULL;
192 	struct rb_node *node = iommu->dma_list.rb_node;
193 	struct vfio_dma *dma_res = NULL;
194 
195 	while (node) {
196 		struct vfio_dma *dma = rb_entry(node, struct vfio_dma, node);
197 
198 		if (start < dma->iova + dma->size) {
199 			res = node;
200 			dma_res = dma;
201 			if (start >= dma->iova)
202 				break;
203 			node = node->rb_left;
204 		} else {
205 			node = node->rb_right;
206 		}
207 	}
208 	if (res && size && dma_res->iova >= start + size)
209 		res = NULL;
210 	return res;
211 }
212 
213 static void vfio_link_dma(struct vfio_iommu *iommu, struct vfio_dma *new)
214 {
215 	struct rb_node **link = &iommu->dma_list.rb_node, *parent = NULL;
216 	struct vfio_dma *dma;
217 
218 	while (*link) {
219 		parent = *link;
220 		dma = rb_entry(parent, struct vfio_dma, node);
221 
222 		if (new->iova + new->size <= dma->iova)
223 			link = &(*link)->rb_left;
224 		else
225 			link = &(*link)->rb_right;
226 	}
227 
228 	rb_link_node(&new->node, parent, link);
229 	rb_insert_color(&new->node, &iommu->dma_list);
230 }
231 
232 static void vfio_unlink_dma(struct vfio_iommu *iommu, struct vfio_dma *old)
233 {
234 	rb_erase(&old->node, &iommu->dma_list);
235 }
236 
237 
238 static int vfio_dma_bitmap_alloc(struct vfio_dma *dma, size_t pgsize)
239 {
240 	uint64_t npages = dma->size / pgsize;
241 
242 	if (npages > DIRTY_BITMAP_PAGES_MAX)
243 		return -EINVAL;
244 
245 	/*
246 	 * Allocate extra 64 bits that are used to calculate shift required for
247 	 * bitmap_shift_left() to manipulate and club unaligned number of pages
248 	 * in adjacent vfio_dma ranges.
249 	 */
250 	dma->bitmap = kvzalloc(DIRTY_BITMAP_BYTES(npages) + sizeof(u64),
251 			       GFP_KERNEL);
252 	if (!dma->bitmap)
253 		return -ENOMEM;
254 
255 	return 0;
256 }
257 
258 static void vfio_dma_bitmap_free(struct vfio_dma *dma)
259 {
260 	kvfree(dma->bitmap);
261 	dma->bitmap = NULL;
262 }
263 
264 static void vfio_dma_populate_bitmap(struct vfio_dma *dma, size_t pgsize)
265 {
266 	struct rb_node *p;
267 	unsigned long pgshift = __ffs(pgsize);
268 
269 	for (p = rb_first(&dma->pfn_list); p; p = rb_next(p)) {
270 		struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn, node);
271 
272 		bitmap_set(dma->bitmap, (vpfn->iova - dma->iova) >> pgshift, 1);
273 	}
274 }
275 
276 static void vfio_iommu_populate_bitmap_full(struct vfio_iommu *iommu)
277 {
278 	struct rb_node *n;
279 	unsigned long pgshift = __ffs(iommu->pgsize_bitmap);
280 
281 	for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
282 		struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
283 
284 		bitmap_set(dma->bitmap, 0, dma->size >> pgshift);
285 	}
286 }
287 
288 static int vfio_dma_bitmap_alloc_all(struct vfio_iommu *iommu, size_t pgsize)
289 {
290 	struct rb_node *n;
291 
292 	for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
293 		struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
294 		int ret;
295 
296 		ret = vfio_dma_bitmap_alloc(dma, pgsize);
297 		if (ret) {
298 			struct rb_node *p;
299 
300 			for (p = rb_prev(n); p; p = rb_prev(p)) {
301 				struct vfio_dma *dma = rb_entry(n,
302 							struct vfio_dma, node);
303 
304 				vfio_dma_bitmap_free(dma);
305 			}
306 			return ret;
307 		}
308 		vfio_dma_populate_bitmap(dma, pgsize);
309 	}
310 	return 0;
311 }
312 
313 static void vfio_dma_bitmap_free_all(struct vfio_iommu *iommu)
314 {
315 	struct rb_node *n;
316 
317 	for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
318 		struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
319 
320 		vfio_dma_bitmap_free(dma);
321 	}
322 }
323 
324 /*
325  * Helper Functions for host iova-pfn list
326  */
327 static struct vfio_pfn *vfio_find_vpfn(struct vfio_dma *dma, dma_addr_t iova)
328 {
329 	struct vfio_pfn *vpfn;
330 	struct rb_node *node = dma->pfn_list.rb_node;
331 
332 	while (node) {
333 		vpfn = rb_entry(node, struct vfio_pfn, node);
334 
335 		if (iova < vpfn->iova)
336 			node = node->rb_left;
337 		else if (iova > vpfn->iova)
338 			node = node->rb_right;
339 		else
340 			return vpfn;
341 	}
342 	return NULL;
343 }
344 
345 static void vfio_link_pfn(struct vfio_dma *dma,
346 			  struct vfio_pfn *new)
347 {
348 	struct rb_node **link, *parent = NULL;
349 	struct vfio_pfn *vpfn;
350 
351 	link = &dma->pfn_list.rb_node;
352 	while (*link) {
353 		parent = *link;
354 		vpfn = rb_entry(parent, struct vfio_pfn, node);
355 
356 		if (new->iova < vpfn->iova)
357 			link = &(*link)->rb_left;
358 		else
359 			link = &(*link)->rb_right;
360 	}
361 
362 	rb_link_node(&new->node, parent, link);
363 	rb_insert_color(&new->node, &dma->pfn_list);
364 }
365 
366 static void vfio_unlink_pfn(struct vfio_dma *dma, struct vfio_pfn *old)
367 {
368 	rb_erase(&old->node, &dma->pfn_list);
369 }
370 
371 static int vfio_add_to_pfn_list(struct vfio_dma *dma, dma_addr_t iova,
372 				unsigned long pfn)
373 {
374 	struct vfio_pfn *vpfn;
375 
376 	vpfn = kzalloc(sizeof(*vpfn), GFP_KERNEL);
377 	if (!vpfn)
378 		return -ENOMEM;
379 
380 	vpfn->iova = iova;
381 	vpfn->pfn = pfn;
382 	vpfn->ref_count = 1;
383 	vfio_link_pfn(dma, vpfn);
384 	return 0;
385 }
386 
387 static void vfio_remove_from_pfn_list(struct vfio_dma *dma,
388 				      struct vfio_pfn *vpfn)
389 {
390 	vfio_unlink_pfn(dma, vpfn);
391 	kfree(vpfn);
392 }
393 
394 static struct vfio_pfn *vfio_iova_get_vfio_pfn(struct vfio_dma *dma,
395 					       unsigned long iova)
396 {
397 	struct vfio_pfn *vpfn = vfio_find_vpfn(dma, iova);
398 
399 	if (vpfn)
400 		vpfn->ref_count++;
401 	return vpfn;
402 }
403 
404 static int vfio_iova_put_vfio_pfn(struct vfio_dma *dma, struct vfio_pfn *vpfn)
405 {
406 	int ret = 0;
407 
408 	vpfn->ref_count--;
409 	if (!vpfn->ref_count) {
410 		ret = put_pfn(vpfn->pfn, dma->prot);
411 		vfio_remove_from_pfn_list(dma, vpfn);
412 	}
413 	return ret;
414 }
415 
416 static int vfio_lock_acct(struct vfio_dma *dma, long npage, bool async)
417 {
418 	struct mm_struct *mm;
419 	int ret;
420 
421 	if (!npage)
422 		return 0;
423 
424 	mm = async ? get_task_mm(dma->task) : dma->task->mm;
425 	if (!mm)
426 		return -ESRCH; /* process exited */
427 
428 	ret = mmap_write_lock_killable(mm);
429 	if (!ret) {
430 		ret = __account_locked_vm(mm, abs(npage), npage > 0, dma->task,
431 					  dma->lock_cap);
432 		mmap_write_unlock(mm);
433 	}
434 
435 	if (async)
436 		mmput(mm);
437 
438 	return ret;
439 }
440 
441 /*
442  * Some mappings aren't backed by a struct page, for example an mmap'd
443  * MMIO range for our own or another device.  These use a different
444  * pfn conversion and shouldn't be tracked as locked pages.
445  * For compound pages, any driver that sets the reserved bit in head
446  * page needs to set the reserved bit in all subpages to be safe.
447  */
448 static bool is_invalid_reserved_pfn(unsigned long pfn)
449 {
450 	if (pfn_valid(pfn))
451 		return PageReserved(pfn_to_page(pfn));
452 
453 	return true;
454 }
455 
456 static int put_pfn(unsigned long pfn, int prot)
457 {
458 	if (!is_invalid_reserved_pfn(pfn)) {
459 		struct page *page = pfn_to_page(pfn);
460 
461 		unpin_user_pages_dirty_lock(&page, 1, prot & IOMMU_WRITE);
462 		return 1;
463 	}
464 	return 0;
465 }
466 
467 #define VFIO_BATCH_MAX_CAPACITY (PAGE_SIZE / sizeof(struct page *))
468 
469 static void vfio_batch_init(struct vfio_batch *batch)
470 {
471 	batch->size = 0;
472 	batch->offset = 0;
473 
474 	if (unlikely(disable_hugepages))
475 		goto fallback;
476 
477 	batch->pages = (struct page **) __get_free_page(GFP_KERNEL);
478 	if (!batch->pages)
479 		goto fallback;
480 
481 	batch->capacity = VFIO_BATCH_MAX_CAPACITY;
482 	return;
483 
484 fallback:
485 	batch->pages = &batch->fallback_page;
486 	batch->capacity = 1;
487 }
488 
489 static void vfio_batch_unpin(struct vfio_batch *batch, struct vfio_dma *dma)
490 {
491 	while (batch->size) {
492 		unsigned long pfn = page_to_pfn(batch->pages[batch->offset]);
493 
494 		put_pfn(pfn, dma->prot);
495 		batch->offset++;
496 		batch->size--;
497 	}
498 }
499 
500 static void vfio_batch_fini(struct vfio_batch *batch)
501 {
502 	if (batch->capacity == VFIO_BATCH_MAX_CAPACITY)
503 		free_page((unsigned long)batch->pages);
504 }
505 
506 static int follow_fault_pfn(struct vm_area_struct *vma, struct mm_struct *mm,
507 			    unsigned long vaddr, unsigned long *pfn,
508 			    bool write_fault)
509 {
510 	pte_t *ptep;
511 	spinlock_t *ptl;
512 	int ret;
513 
514 	ret = follow_pte(vma->vm_mm, vaddr, &ptep, &ptl);
515 	if (ret) {
516 		bool unlocked = false;
517 
518 		ret = fixup_user_fault(mm, vaddr,
519 				       FAULT_FLAG_REMOTE |
520 				       (write_fault ?  FAULT_FLAG_WRITE : 0),
521 				       &unlocked);
522 		if (unlocked)
523 			return -EAGAIN;
524 
525 		if (ret)
526 			return ret;
527 
528 		ret = follow_pte(vma->vm_mm, vaddr, &ptep, &ptl);
529 		if (ret)
530 			return ret;
531 	}
532 
533 	if (write_fault && !pte_write(*ptep))
534 		ret = -EFAULT;
535 	else
536 		*pfn = pte_pfn(*ptep);
537 
538 	pte_unmap_unlock(ptep, ptl);
539 	return ret;
540 }
541 
542 /*
543  * Returns the positive number of pfns successfully obtained or a negative
544  * error code.
545  */
546 static int vaddr_get_pfns(struct mm_struct *mm, unsigned long vaddr,
547 			  long npages, int prot, unsigned long *pfn,
548 			  struct page **pages)
549 {
550 	struct vm_area_struct *vma;
551 	unsigned int flags = 0;
552 	int ret;
553 
554 	if (prot & IOMMU_WRITE)
555 		flags |= FOLL_WRITE;
556 
557 	mmap_read_lock(mm);
558 	ret = pin_user_pages_remote(mm, vaddr, npages, flags | FOLL_LONGTERM,
559 				    pages, NULL, NULL);
560 	if (ret > 0) {
561 		int i;
562 
563 		/*
564 		 * The zero page is always resident, we don't need to pin it
565 		 * and it falls into our invalid/reserved test so we don't
566 		 * unpin in put_pfn().  Unpin all zero pages in the batch here.
567 		 */
568 		for (i = 0 ; i < ret; i++) {
569 			if (unlikely(is_zero_pfn(page_to_pfn(pages[i]))))
570 				unpin_user_page(pages[i]);
571 		}
572 
573 		*pfn = page_to_pfn(pages[0]);
574 		goto done;
575 	}
576 
577 	vaddr = untagged_addr(vaddr);
578 
579 retry:
580 	vma = vma_lookup(mm, vaddr);
581 
582 	if (vma && vma->vm_flags & VM_PFNMAP) {
583 		ret = follow_fault_pfn(vma, mm, vaddr, pfn, prot & IOMMU_WRITE);
584 		if (ret == -EAGAIN)
585 			goto retry;
586 
587 		if (!ret) {
588 			if (is_invalid_reserved_pfn(*pfn))
589 				ret = 1;
590 			else
591 				ret = -EFAULT;
592 		}
593 	}
594 done:
595 	mmap_read_unlock(mm);
596 	return ret;
597 }
598 
599 static int vfio_wait(struct vfio_iommu *iommu)
600 {
601 	DEFINE_WAIT(wait);
602 
603 	prepare_to_wait(&iommu->vaddr_wait, &wait, TASK_KILLABLE);
604 	mutex_unlock(&iommu->lock);
605 	schedule();
606 	mutex_lock(&iommu->lock);
607 	finish_wait(&iommu->vaddr_wait, &wait);
608 	if (kthread_should_stop() || !iommu->container_open ||
609 	    fatal_signal_pending(current)) {
610 		return -EFAULT;
611 	}
612 	return WAITED;
613 }
614 
615 /*
616  * Find dma struct and wait for its vaddr to be valid.  iommu lock is dropped
617  * if the task waits, but is re-locked on return.  Return result in *dma_p.
618  * Return 0 on success with no waiting, WAITED on success if waited, and -errno
619  * on error.
620  */
621 static int vfio_find_dma_valid(struct vfio_iommu *iommu, dma_addr_t start,
622 			       size_t size, struct vfio_dma **dma_p)
623 {
624 	int ret = 0;
625 
626 	do {
627 		*dma_p = vfio_find_dma(iommu, start, size);
628 		if (!*dma_p)
629 			return -EINVAL;
630 		else if (!(*dma_p)->vaddr_invalid)
631 			return ret;
632 		else
633 			ret = vfio_wait(iommu);
634 	} while (ret == WAITED);
635 
636 	return ret;
637 }
638 
639 /*
640  * Wait for all vaddr in the dma_list to become valid.  iommu lock is dropped
641  * if the task waits, but is re-locked on return.  Return 0 on success with no
642  * waiting, WAITED on success if waited, and -errno on error.
643  */
644 static int vfio_wait_all_valid(struct vfio_iommu *iommu)
645 {
646 	int ret = 0;
647 
648 	while (iommu->vaddr_invalid_count && ret >= 0)
649 		ret = vfio_wait(iommu);
650 
651 	return ret;
652 }
653 
654 /*
655  * Attempt to pin pages.  We really don't want to track all the pfns and
656  * the iommu can only map chunks of consecutive pfns anyway, so get the
657  * first page and all consecutive pages with the same locking.
658  */
659 static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
660 				  long npage, unsigned long *pfn_base,
661 				  unsigned long limit, struct vfio_batch *batch)
662 {
663 	unsigned long pfn;
664 	struct mm_struct *mm = current->mm;
665 	long ret, pinned = 0, lock_acct = 0;
666 	bool rsvd;
667 	dma_addr_t iova = vaddr - dma->vaddr + dma->iova;
668 
669 	/* This code path is only user initiated */
670 	if (!mm)
671 		return -ENODEV;
672 
673 	if (batch->size) {
674 		/* Leftover pages in batch from an earlier call. */
675 		*pfn_base = page_to_pfn(batch->pages[batch->offset]);
676 		pfn = *pfn_base;
677 		rsvd = is_invalid_reserved_pfn(*pfn_base);
678 	} else {
679 		*pfn_base = 0;
680 	}
681 
682 	while (npage) {
683 		if (!batch->size) {
684 			/* Empty batch, so refill it. */
685 			long req_pages = min_t(long, npage, batch->capacity);
686 
687 			ret = vaddr_get_pfns(mm, vaddr, req_pages, dma->prot,
688 					     &pfn, batch->pages);
689 			if (ret < 0)
690 				goto unpin_out;
691 
692 			batch->size = ret;
693 			batch->offset = 0;
694 
695 			if (!*pfn_base) {
696 				*pfn_base = pfn;
697 				rsvd = is_invalid_reserved_pfn(*pfn_base);
698 			}
699 		}
700 
701 		/*
702 		 * pfn is preset for the first iteration of this inner loop and
703 		 * updated at the end to handle a VM_PFNMAP pfn.  In that case,
704 		 * batch->pages isn't valid (there's no struct page), so allow
705 		 * batch->pages to be touched only when there's more than one
706 		 * pfn to check, which guarantees the pfns are from a
707 		 * !VM_PFNMAP vma.
708 		 */
709 		while (true) {
710 			if (pfn != *pfn_base + pinned ||
711 			    rsvd != is_invalid_reserved_pfn(pfn))
712 				goto out;
713 
714 			/*
715 			 * Reserved pages aren't counted against the user,
716 			 * externally pinned pages are already counted against
717 			 * the user.
718 			 */
719 			if (!rsvd && !vfio_find_vpfn(dma, iova)) {
720 				if (!dma->lock_cap &&
721 				    mm->locked_vm + lock_acct + 1 > limit) {
722 					pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n",
723 						__func__, limit << PAGE_SHIFT);
724 					ret = -ENOMEM;
725 					goto unpin_out;
726 				}
727 				lock_acct++;
728 			}
729 
730 			pinned++;
731 			npage--;
732 			vaddr += PAGE_SIZE;
733 			iova += PAGE_SIZE;
734 			batch->offset++;
735 			batch->size--;
736 
737 			if (!batch->size)
738 				break;
739 
740 			pfn = page_to_pfn(batch->pages[batch->offset]);
741 		}
742 
743 		if (unlikely(disable_hugepages))
744 			break;
745 	}
746 
747 out:
748 	ret = vfio_lock_acct(dma, lock_acct, false);
749 
750 unpin_out:
751 	if (batch->size == 1 && !batch->offset) {
752 		/* May be a VM_PFNMAP pfn, which the batch can't remember. */
753 		put_pfn(pfn, dma->prot);
754 		batch->size = 0;
755 	}
756 
757 	if (ret < 0) {
758 		if (pinned && !rsvd) {
759 			for (pfn = *pfn_base ; pinned ; pfn++, pinned--)
760 				put_pfn(pfn, dma->prot);
761 		}
762 		vfio_batch_unpin(batch, dma);
763 
764 		return ret;
765 	}
766 
767 	return pinned;
768 }
769 
770 static long vfio_unpin_pages_remote(struct vfio_dma *dma, dma_addr_t iova,
771 				    unsigned long pfn, long npage,
772 				    bool do_accounting)
773 {
774 	long unlocked = 0, locked = 0;
775 	long i;
776 
777 	for (i = 0; i < npage; i++, iova += PAGE_SIZE) {
778 		if (put_pfn(pfn++, dma->prot)) {
779 			unlocked++;
780 			if (vfio_find_vpfn(dma, iova))
781 				locked++;
782 		}
783 	}
784 
785 	if (do_accounting)
786 		vfio_lock_acct(dma, locked - unlocked, true);
787 
788 	return unlocked;
789 }
790 
791 static int vfio_pin_page_external(struct vfio_dma *dma, unsigned long vaddr,
792 				  unsigned long *pfn_base, bool do_accounting)
793 {
794 	struct page *pages[1];
795 	struct mm_struct *mm;
796 	int ret;
797 
798 	mm = get_task_mm(dma->task);
799 	if (!mm)
800 		return -ENODEV;
801 
802 	ret = vaddr_get_pfns(mm, vaddr, 1, dma->prot, pfn_base, pages);
803 	if (ret != 1)
804 		goto out;
805 
806 	ret = 0;
807 
808 	if (do_accounting && !is_invalid_reserved_pfn(*pfn_base)) {
809 		ret = vfio_lock_acct(dma, 1, true);
810 		if (ret) {
811 			put_pfn(*pfn_base, dma->prot);
812 			if (ret == -ENOMEM)
813 				pr_warn("%s: Task %s (%d) RLIMIT_MEMLOCK "
814 					"(%ld) exceeded\n", __func__,
815 					dma->task->comm, task_pid_nr(dma->task),
816 					task_rlimit(dma->task, RLIMIT_MEMLOCK));
817 		}
818 	}
819 
820 out:
821 	mmput(mm);
822 	return ret;
823 }
824 
825 static int vfio_unpin_page_external(struct vfio_dma *dma, dma_addr_t iova,
826 				    bool do_accounting)
827 {
828 	int unlocked;
829 	struct vfio_pfn *vpfn = vfio_find_vpfn(dma, iova);
830 
831 	if (!vpfn)
832 		return 0;
833 
834 	unlocked = vfio_iova_put_vfio_pfn(dma, vpfn);
835 
836 	if (do_accounting)
837 		vfio_lock_acct(dma, -unlocked, true);
838 
839 	return unlocked;
840 }
841 
842 static int vfio_iommu_type1_pin_pages(void *iommu_data,
843 				      struct iommu_group *iommu_group,
844 				      dma_addr_t user_iova,
845 				      int npage, int prot,
846 				      struct page **pages)
847 {
848 	struct vfio_iommu *iommu = iommu_data;
849 	struct vfio_iommu_group *group;
850 	int i, j, ret;
851 	unsigned long remote_vaddr;
852 	struct vfio_dma *dma;
853 	bool do_accounting;
854 	dma_addr_t iova;
855 
856 	if (!iommu || !pages)
857 		return -EINVAL;
858 
859 	/* Supported for v2 version only */
860 	if (!iommu->v2)
861 		return -EACCES;
862 
863 	mutex_lock(&iommu->lock);
864 
865 	/*
866 	 * Wait for all necessary vaddr's to be valid so they can be used in
867 	 * the main loop without dropping the lock, to avoid racing vs unmap.
868 	 */
869 again:
870 	if (iommu->vaddr_invalid_count) {
871 		for (i = 0; i < npage; i++) {
872 			iova = user_iova + PAGE_SIZE * i;
873 			ret = vfio_find_dma_valid(iommu, iova, PAGE_SIZE, &dma);
874 			if (ret < 0)
875 				goto pin_done;
876 			if (ret == WAITED)
877 				goto again;
878 		}
879 	}
880 
881 	/* Fail if no dma_umap notifier is registered */
882 	if (list_empty(&iommu->device_list)) {
883 		ret = -EINVAL;
884 		goto pin_done;
885 	}
886 
887 	/*
888 	 * If iommu capable domain exist in the container then all pages are
889 	 * already pinned and accounted. Accounting should be done if there is no
890 	 * iommu capable domain in the container.
891 	 */
892 	do_accounting = list_empty(&iommu->domain_list);
893 
894 	for (i = 0; i < npage; i++) {
895 		unsigned long phys_pfn;
896 		struct vfio_pfn *vpfn;
897 
898 		iova = user_iova + PAGE_SIZE * i;
899 		dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
900 		if (!dma) {
901 			ret = -EINVAL;
902 			goto pin_unwind;
903 		}
904 
905 		if ((dma->prot & prot) != prot) {
906 			ret = -EPERM;
907 			goto pin_unwind;
908 		}
909 
910 		vpfn = vfio_iova_get_vfio_pfn(dma, iova);
911 		if (vpfn) {
912 			pages[i] = pfn_to_page(vpfn->pfn);
913 			continue;
914 		}
915 
916 		remote_vaddr = dma->vaddr + (iova - dma->iova);
917 		ret = vfio_pin_page_external(dma, remote_vaddr, &phys_pfn,
918 					     do_accounting);
919 		if (ret)
920 			goto pin_unwind;
921 
922 		ret = vfio_add_to_pfn_list(dma, iova, phys_pfn);
923 		if (ret) {
924 			if (put_pfn(phys_pfn, dma->prot) && do_accounting)
925 				vfio_lock_acct(dma, -1, true);
926 			goto pin_unwind;
927 		}
928 
929 		pages[i] = pfn_to_page(phys_pfn);
930 
931 		if (iommu->dirty_page_tracking) {
932 			unsigned long pgshift = __ffs(iommu->pgsize_bitmap);
933 
934 			/*
935 			 * Bitmap populated with the smallest supported page
936 			 * size
937 			 */
938 			bitmap_set(dma->bitmap,
939 				   (iova - dma->iova) >> pgshift, 1);
940 		}
941 	}
942 	ret = i;
943 
944 	group = vfio_iommu_find_iommu_group(iommu, iommu_group);
945 	if (!group->pinned_page_dirty_scope) {
946 		group->pinned_page_dirty_scope = true;
947 		iommu->num_non_pinned_groups--;
948 	}
949 
950 	goto pin_done;
951 
952 pin_unwind:
953 	pages[i] = NULL;
954 	for (j = 0; j < i; j++) {
955 		dma_addr_t iova;
956 
957 		iova = user_iova + PAGE_SIZE * j;
958 		dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
959 		vfio_unpin_page_external(dma, iova, do_accounting);
960 		pages[j] = NULL;
961 	}
962 pin_done:
963 	mutex_unlock(&iommu->lock);
964 	return ret;
965 }
966 
967 static void vfio_iommu_type1_unpin_pages(void *iommu_data,
968 					 dma_addr_t user_iova, int npage)
969 {
970 	struct vfio_iommu *iommu = iommu_data;
971 	bool do_accounting;
972 	int i;
973 
974 	/* Supported for v2 version only */
975 	if (WARN_ON(!iommu->v2))
976 		return;
977 
978 	mutex_lock(&iommu->lock);
979 
980 	do_accounting = list_empty(&iommu->domain_list);
981 	for (i = 0; i < npage; i++) {
982 		dma_addr_t iova = user_iova + PAGE_SIZE * i;
983 		struct vfio_dma *dma;
984 
985 		dma = vfio_find_dma(iommu, iova, PAGE_SIZE);
986 		if (!dma)
987 			break;
988 
989 		vfio_unpin_page_external(dma, iova, do_accounting);
990 	}
991 
992 	mutex_unlock(&iommu->lock);
993 
994 	WARN_ON(i != npage);
995 }
996 
997 static long vfio_sync_unpin(struct vfio_dma *dma, struct vfio_domain *domain,
998 			    struct list_head *regions,
999 			    struct iommu_iotlb_gather *iotlb_gather)
1000 {
1001 	long unlocked = 0;
1002 	struct vfio_regions *entry, *next;
1003 
1004 	iommu_iotlb_sync(domain->domain, iotlb_gather);
1005 
1006 	list_for_each_entry_safe(entry, next, regions, list) {
1007 		unlocked += vfio_unpin_pages_remote(dma,
1008 						    entry->iova,
1009 						    entry->phys >> PAGE_SHIFT,
1010 						    entry->len >> PAGE_SHIFT,
1011 						    false);
1012 		list_del(&entry->list);
1013 		kfree(entry);
1014 	}
1015 
1016 	cond_resched();
1017 
1018 	return unlocked;
1019 }
1020 
1021 /*
1022  * Generally, VFIO needs to unpin remote pages after each IOTLB flush.
1023  * Therefore, when using IOTLB flush sync interface, VFIO need to keep track
1024  * of these regions (currently using a list).
1025  *
1026  * This value specifies maximum number of regions for each IOTLB flush sync.
1027  */
1028 #define VFIO_IOMMU_TLB_SYNC_MAX		512
1029 
1030 static size_t unmap_unpin_fast(struct vfio_domain *domain,
1031 			       struct vfio_dma *dma, dma_addr_t *iova,
1032 			       size_t len, phys_addr_t phys, long *unlocked,
1033 			       struct list_head *unmapped_list,
1034 			       int *unmapped_cnt,
1035 			       struct iommu_iotlb_gather *iotlb_gather)
1036 {
1037 	size_t unmapped = 0;
1038 	struct vfio_regions *entry = kzalloc(sizeof(*entry), GFP_KERNEL);
1039 
1040 	if (entry) {
1041 		unmapped = iommu_unmap_fast(domain->domain, *iova, len,
1042 					    iotlb_gather);
1043 
1044 		if (!unmapped) {
1045 			kfree(entry);
1046 		} else {
1047 			entry->iova = *iova;
1048 			entry->phys = phys;
1049 			entry->len  = unmapped;
1050 			list_add_tail(&entry->list, unmapped_list);
1051 
1052 			*iova += unmapped;
1053 			(*unmapped_cnt)++;
1054 		}
1055 	}
1056 
1057 	/*
1058 	 * Sync if the number of fast-unmap regions hits the limit
1059 	 * or in case of errors.
1060 	 */
1061 	if (*unmapped_cnt >= VFIO_IOMMU_TLB_SYNC_MAX || !unmapped) {
1062 		*unlocked += vfio_sync_unpin(dma, domain, unmapped_list,
1063 					     iotlb_gather);
1064 		*unmapped_cnt = 0;
1065 	}
1066 
1067 	return unmapped;
1068 }
1069 
1070 static size_t unmap_unpin_slow(struct vfio_domain *domain,
1071 			       struct vfio_dma *dma, dma_addr_t *iova,
1072 			       size_t len, phys_addr_t phys,
1073 			       long *unlocked)
1074 {
1075 	size_t unmapped = iommu_unmap(domain->domain, *iova, len);
1076 
1077 	if (unmapped) {
1078 		*unlocked += vfio_unpin_pages_remote(dma, *iova,
1079 						     phys >> PAGE_SHIFT,
1080 						     unmapped >> PAGE_SHIFT,
1081 						     false);
1082 		*iova += unmapped;
1083 		cond_resched();
1084 	}
1085 	return unmapped;
1086 }
1087 
1088 static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma,
1089 			     bool do_accounting)
1090 {
1091 	dma_addr_t iova = dma->iova, end = dma->iova + dma->size;
1092 	struct vfio_domain *domain, *d;
1093 	LIST_HEAD(unmapped_region_list);
1094 	struct iommu_iotlb_gather iotlb_gather;
1095 	int unmapped_region_cnt = 0;
1096 	long unlocked = 0;
1097 
1098 	if (!dma->size)
1099 		return 0;
1100 
1101 	if (list_empty(&iommu->domain_list))
1102 		return 0;
1103 
1104 	/*
1105 	 * We use the IOMMU to track the physical addresses, otherwise we'd
1106 	 * need a much more complicated tracking system.  Unfortunately that
1107 	 * means we need to use one of the iommu domains to figure out the
1108 	 * pfns to unpin.  The rest need to be unmapped in advance so we have
1109 	 * no iommu translations remaining when the pages are unpinned.
1110 	 */
1111 	domain = d = list_first_entry(&iommu->domain_list,
1112 				      struct vfio_domain, next);
1113 
1114 	list_for_each_entry_continue(d, &iommu->domain_list, next) {
1115 		iommu_unmap(d->domain, dma->iova, dma->size);
1116 		cond_resched();
1117 	}
1118 
1119 	iommu_iotlb_gather_init(&iotlb_gather);
1120 	while (iova < end) {
1121 		size_t unmapped, len;
1122 		phys_addr_t phys, next;
1123 
1124 		phys = iommu_iova_to_phys(domain->domain, iova);
1125 		if (WARN_ON(!phys)) {
1126 			iova += PAGE_SIZE;
1127 			continue;
1128 		}
1129 
1130 		/*
1131 		 * To optimize for fewer iommu_unmap() calls, each of which
1132 		 * may require hardware cache flushing, try to find the
1133 		 * largest contiguous physical memory chunk to unmap.
1134 		 */
1135 		for (len = PAGE_SIZE;
1136 		     !domain->fgsp && iova + len < end; len += PAGE_SIZE) {
1137 			next = iommu_iova_to_phys(domain->domain, iova + len);
1138 			if (next != phys + len)
1139 				break;
1140 		}
1141 
1142 		/*
1143 		 * First, try to use fast unmap/unpin. In case of failure,
1144 		 * switch to slow unmap/unpin path.
1145 		 */
1146 		unmapped = unmap_unpin_fast(domain, dma, &iova, len, phys,
1147 					    &unlocked, &unmapped_region_list,
1148 					    &unmapped_region_cnt,
1149 					    &iotlb_gather);
1150 		if (!unmapped) {
1151 			unmapped = unmap_unpin_slow(domain, dma, &iova, len,
1152 						    phys, &unlocked);
1153 			if (WARN_ON(!unmapped))
1154 				break;
1155 		}
1156 	}
1157 
1158 	dma->iommu_mapped = false;
1159 
1160 	if (unmapped_region_cnt) {
1161 		unlocked += vfio_sync_unpin(dma, domain, &unmapped_region_list,
1162 					    &iotlb_gather);
1163 	}
1164 
1165 	if (do_accounting) {
1166 		vfio_lock_acct(dma, -unlocked, true);
1167 		return 0;
1168 	}
1169 	return unlocked;
1170 }
1171 
1172 static void vfio_remove_dma(struct vfio_iommu *iommu, struct vfio_dma *dma)
1173 {
1174 	WARN_ON(!RB_EMPTY_ROOT(&dma->pfn_list));
1175 	vfio_unmap_unpin(iommu, dma, true);
1176 	vfio_unlink_dma(iommu, dma);
1177 	put_task_struct(dma->task);
1178 	vfio_dma_bitmap_free(dma);
1179 	if (dma->vaddr_invalid) {
1180 		iommu->vaddr_invalid_count--;
1181 		wake_up_all(&iommu->vaddr_wait);
1182 	}
1183 	kfree(dma);
1184 	iommu->dma_avail++;
1185 }
1186 
1187 static void vfio_update_pgsize_bitmap(struct vfio_iommu *iommu)
1188 {
1189 	struct vfio_domain *domain;
1190 
1191 	iommu->pgsize_bitmap = ULONG_MAX;
1192 
1193 	list_for_each_entry(domain, &iommu->domain_list, next)
1194 		iommu->pgsize_bitmap &= domain->domain->pgsize_bitmap;
1195 
1196 	/*
1197 	 * In case the IOMMU supports page sizes smaller than PAGE_SIZE
1198 	 * we pretend PAGE_SIZE is supported and hide sub-PAGE_SIZE sizes.
1199 	 * That way the user will be able to map/unmap buffers whose size/
1200 	 * start address is aligned with PAGE_SIZE. Pinning code uses that
1201 	 * granularity while iommu driver can use the sub-PAGE_SIZE size
1202 	 * to map the buffer.
1203 	 */
1204 	if (iommu->pgsize_bitmap & ~PAGE_MASK) {
1205 		iommu->pgsize_bitmap &= PAGE_MASK;
1206 		iommu->pgsize_bitmap |= PAGE_SIZE;
1207 	}
1208 }
1209 
1210 static int update_user_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu,
1211 			      struct vfio_dma *dma, dma_addr_t base_iova,
1212 			      size_t pgsize)
1213 {
1214 	unsigned long pgshift = __ffs(pgsize);
1215 	unsigned long nbits = dma->size >> pgshift;
1216 	unsigned long bit_offset = (dma->iova - base_iova) >> pgshift;
1217 	unsigned long copy_offset = bit_offset / BITS_PER_LONG;
1218 	unsigned long shift = bit_offset % BITS_PER_LONG;
1219 	unsigned long leftover;
1220 
1221 	/*
1222 	 * mark all pages dirty if any IOMMU capable device is not able
1223 	 * to report dirty pages and all pages are pinned and mapped.
1224 	 */
1225 	if (iommu->num_non_pinned_groups && dma->iommu_mapped)
1226 		bitmap_set(dma->bitmap, 0, nbits);
1227 
1228 	if (shift) {
1229 		bitmap_shift_left(dma->bitmap, dma->bitmap, shift,
1230 				  nbits + shift);
1231 
1232 		if (copy_from_user(&leftover,
1233 				   (void __user *)(bitmap + copy_offset),
1234 				   sizeof(leftover)))
1235 			return -EFAULT;
1236 
1237 		bitmap_or(dma->bitmap, dma->bitmap, &leftover, shift);
1238 	}
1239 
1240 	if (copy_to_user((void __user *)(bitmap + copy_offset), dma->bitmap,
1241 			 DIRTY_BITMAP_BYTES(nbits + shift)))
1242 		return -EFAULT;
1243 
1244 	return 0;
1245 }
1246 
1247 static int vfio_iova_dirty_bitmap(u64 __user *bitmap, struct vfio_iommu *iommu,
1248 				  dma_addr_t iova, size_t size, size_t pgsize)
1249 {
1250 	struct vfio_dma *dma;
1251 	struct rb_node *n;
1252 	unsigned long pgshift = __ffs(pgsize);
1253 	int ret;
1254 
1255 	/*
1256 	 * GET_BITMAP request must fully cover vfio_dma mappings.  Multiple
1257 	 * vfio_dma mappings may be clubbed by specifying large ranges, but
1258 	 * there must not be any previous mappings bisected by the range.
1259 	 * An error will be returned if these conditions are not met.
1260 	 */
1261 	dma = vfio_find_dma(iommu, iova, 1);
1262 	if (dma && dma->iova != iova)
1263 		return -EINVAL;
1264 
1265 	dma = vfio_find_dma(iommu, iova + size - 1, 0);
1266 	if (dma && dma->iova + dma->size != iova + size)
1267 		return -EINVAL;
1268 
1269 	for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
1270 		struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
1271 
1272 		if (dma->iova < iova)
1273 			continue;
1274 
1275 		if (dma->iova > iova + size - 1)
1276 			break;
1277 
1278 		ret = update_user_bitmap(bitmap, iommu, dma, iova, pgsize);
1279 		if (ret)
1280 			return ret;
1281 
1282 		/*
1283 		 * Re-populate bitmap to include all pinned pages which are
1284 		 * considered as dirty but exclude pages which are unpinned and
1285 		 * pages which are marked dirty by vfio_dma_rw()
1286 		 */
1287 		bitmap_clear(dma->bitmap, 0, dma->size >> pgshift);
1288 		vfio_dma_populate_bitmap(dma, pgsize);
1289 	}
1290 	return 0;
1291 }
1292 
1293 static int verify_bitmap_size(uint64_t npages, uint64_t bitmap_size)
1294 {
1295 	if (!npages || !bitmap_size || (bitmap_size > DIRTY_BITMAP_SIZE_MAX) ||
1296 	    (bitmap_size < DIRTY_BITMAP_BYTES(npages)))
1297 		return -EINVAL;
1298 
1299 	return 0;
1300 }
1301 
1302 /*
1303  * Notify VFIO drivers using vfio_register_emulated_iommu_dev() to invalidate
1304  * and unmap iovas within the range we're about to unmap. Drivers MUST unpin
1305  * pages in response to an invalidation.
1306  */
1307 static void vfio_notify_dma_unmap(struct vfio_iommu *iommu,
1308 				  struct vfio_dma *dma)
1309 {
1310 	struct vfio_device *device;
1311 
1312 	if (list_empty(&iommu->device_list))
1313 		return;
1314 
1315 	/*
1316 	 * The device is expected to call vfio_unpin_pages() for any IOVA it has
1317 	 * pinned within the range. Since vfio_unpin_pages() will eventually
1318 	 * call back down to this code and try to obtain the iommu->lock we must
1319 	 * drop it.
1320 	 */
1321 	mutex_lock(&iommu->device_list_lock);
1322 	mutex_unlock(&iommu->lock);
1323 
1324 	list_for_each_entry(device, &iommu->device_list, iommu_entry)
1325 		device->ops->dma_unmap(device, dma->iova, dma->size);
1326 
1327 	mutex_unlock(&iommu->device_list_lock);
1328 	mutex_lock(&iommu->lock);
1329 }
1330 
1331 static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
1332 			     struct vfio_iommu_type1_dma_unmap *unmap,
1333 			     struct vfio_bitmap *bitmap)
1334 {
1335 	struct vfio_dma *dma, *dma_last = NULL;
1336 	size_t unmapped = 0, pgsize;
1337 	int ret = -EINVAL, retries = 0;
1338 	unsigned long pgshift;
1339 	dma_addr_t iova = unmap->iova;
1340 	u64 size = unmap->size;
1341 	bool unmap_all = unmap->flags & VFIO_DMA_UNMAP_FLAG_ALL;
1342 	bool invalidate_vaddr = unmap->flags & VFIO_DMA_UNMAP_FLAG_VADDR;
1343 	struct rb_node *n, *first_n;
1344 
1345 	mutex_lock(&iommu->lock);
1346 
1347 	pgshift = __ffs(iommu->pgsize_bitmap);
1348 	pgsize = (size_t)1 << pgshift;
1349 
1350 	if (iova & (pgsize - 1))
1351 		goto unlock;
1352 
1353 	if (unmap_all) {
1354 		if (iova || size)
1355 			goto unlock;
1356 		size = U64_MAX;
1357 	} else if (!size || size & (pgsize - 1) ||
1358 		   iova + size - 1 < iova || size > SIZE_MAX) {
1359 		goto unlock;
1360 	}
1361 
1362 	/* When dirty tracking is enabled, allow only min supported pgsize */
1363 	if ((unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) &&
1364 	    (!iommu->dirty_page_tracking || (bitmap->pgsize != pgsize))) {
1365 		goto unlock;
1366 	}
1367 
1368 	WARN_ON((pgsize - 1) & PAGE_MASK);
1369 again:
1370 	/*
1371 	 * vfio-iommu-type1 (v1) - User mappings were coalesced together to
1372 	 * avoid tracking individual mappings.  This means that the granularity
1373 	 * of the original mapping was lost and the user was allowed to attempt
1374 	 * to unmap any range.  Depending on the contiguousness of physical
1375 	 * memory and page sizes supported by the IOMMU, arbitrary unmaps may
1376 	 * or may not have worked.  We only guaranteed unmap granularity
1377 	 * matching the original mapping; even though it was untracked here,
1378 	 * the original mappings are reflected in IOMMU mappings.  This
1379 	 * resulted in a couple unusual behaviors.  First, if a range is not
1380 	 * able to be unmapped, ex. a set of 4k pages that was mapped as a
1381 	 * 2M hugepage into the IOMMU, the unmap ioctl returns success but with
1382 	 * a zero sized unmap.  Also, if an unmap request overlaps the first
1383 	 * address of a hugepage, the IOMMU will unmap the entire hugepage.
1384 	 * This also returns success and the returned unmap size reflects the
1385 	 * actual size unmapped.
1386 	 *
1387 	 * We attempt to maintain compatibility with this "v1" interface, but
1388 	 * we take control out of the hands of the IOMMU.  Therefore, an unmap
1389 	 * request offset from the beginning of the original mapping will
1390 	 * return success with zero sized unmap.  And an unmap request covering
1391 	 * the first iova of mapping will unmap the entire range.
1392 	 *
1393 	 * The v2 version of this interface intends to be more deterministic.
1394 	 * Unmap requests must fully cover previous mappings.  Multiple
1395 	 * mappings may still be unmaped by specifying large ranges, but there
1396 	 * must not be any previous mappings bisected by the range.  An error
1397 	 * will be returned if these conditions are not met.  The v2 interface
1398 	 * will only return success and a size of zero if there were no
1399 	 * mappings within the range.
1400 	 */
1401 	if (iommu->v2 && !unmap_all) {
1402 		dma = vfio_find_dma(iommu, iova, 1);
1403 		if (dma && dma->iova != iova)
1404 			goto unlock;
1405 
1406 		dma = vfio_find_dma(iommu, iova + size - 1, 0);
1407 		if (dma && dma->iova + dma->size != iova + size)
1408 			goto unlock;
1409 	}
1410 
1411 	ret = 0;
1412 	n = first_n = vfio_find_dma_first_node(iommu, iova, size);
1413 
1414 	while (n) {
1415 		dma = rb_entry(n, struct vfio_dma, node);
1416 		if (dma->iova >= iova + size)
1417 			break;
1418 
1419 		if (!iommu->v2 && iova > dma->iova)
1420 			break;
1421 
1422 		if (invalidate_vaddr) {
1423 			if (dma->vaddr_invalid) {
1424 				struct rb_node *last_n = n;
1425 
1426 				for (n = first_n; n != last_n; n = rb_next(n)) {
1427 					dma = rb_entry(n,
1428 						       struct vfio_dma, node);
1429 					dma->vaddr_invalid = false;
1430 					iommu->vaddr_invalid_count--;
1431 				}
1432 				ret = -EINVAL;
1433 				unmapped = 0;
1434 				break;
1435 			}
1436 			dma->vaddr_invalid = true;
1437 			iommu->vaddr_invalid_count++;
1438 			unmapped += dma->size;
1439 			n = rb_next(n);
1440 			continue;
1441 		}
1442 
1443 		if (!RB_EMPTY_ROOT(&dma->pfn_list)) {
1444 			if (dma_last == dma) {
1445 				BUG_ON(++retries > 10);
1446 			} else {
1447 				dma_last = dma;
1448 				retries = 0;
1449 			}
1450 
1451 			vfio_notify_dma_unmap(iommu, dma);
1452 			goto again;
1453 		}
1454 
1455 		if (unmap->flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) {
1456 			ret = update_user_bitmap(bitmap->data, iommu, dma,
1457 						 iova, pgsize);
1458 			if (ret)
1459 				break;
1460 		}
1461 
1462 		unmapped += dma->size;
1463 		n = rb_next(n);
1464 		vfio_remove_dma(iommu, dma);
1465 	}
1466 
1467 unlock:
1468 	mutex_unlock(&iommu->lock);
1469 
1470 	/* Report how much was unmapped */
1471 	unmap->size = unmapped;
1472 
1473 	return ret;
1474 }
1475 
1476 static int vfio_iommu_map(struct vfio_iommu *iommu, dma_addr_t iova,
1477 			  unsigned long pfn, long npage, int prot)
1478 {
1479 	struct vfio_domain *d;
1480 	int ret;
1481 
1482 	list_for_each_entry(d, &iommu->domain_list, next) {
1483 		ret = iommu_map(d->domain, iova, (phys_addr_t)pfn << PAGE_SHIFT,
1484 				npage << PAGE_SHIFT, prot | IOMMU_CACHE);
1485 		if (ret)
1486 			goto unwind;
1487 
1488 		cond_resched();
1489 	}
1490 
1491 	return 0;
1492 
1493 unwind:
1494 	list_for_each_entry_continue_reverse(d, &iommu->domain_list, next) {
1495 		iommu_unmap(d->domain, iova, npage << PAGE_SHIFT);
1496 		cond_resched();
1497 	}
1498 
1499 	return ret;
1500 }
1501 
1502 static int vfio_pin_map_dma(struct vfio_iommu *iommu, struct vfio_dma *dma,
1503 			    size_t map_size)
1504 {
1505 	dma_addr_t iova = dma->iova;
1506 	unsigned long vaddr = dma->vaddr;
1507 	struct vfio_batch batch;
1508 	size_t size = map_size;
1509 	long npage;
1510 	unsigned long pfn, limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
1511 	int ret = 0;
1512 
1513 	vfio_batch_init(&batch);
1514 
1515 	while (size) {
1516 		/* Pin a contiguous chunk of memory */
1517 		npage = vfio_pin_pages_remote(dma, vaddr + dma->size,
1518 					      size >> PAGE_SHIFT, &pfn, limit,
1519 					      &batch);
1520 		if (npage <= 0) {
1521 			WARN_ON(!npage);
1522 			ret = (int)npage;
1523 			break;
1524 		}
1525 
1526 		/* Map it! */
1527 		ret = vfio_iommu_map(iommu, iova + dma->size, pfn, npage,
1528 				     dma->prot);
1529 		if (ret) {
1530 			vfio_unpin_pages_remote(dma, iova + dma->size, pfn,
1531 						npage, true);
1532 			vfio_batch_unpin(&batch, dma);
1533 			break;
1534 		}
1535 
1536 		size -= npage << PAGE_SHIFT;
1537 		dma->size += npage << PAGE_SHIFT;
1538 	}
1539 
1540 	vfio_batch_fini(&batch);
1541 	dma->iommu_mapped = true;
1542 
1543 	if (ret)
1544 		vfio_remove_dma(iommu, dma);
1545 
1546 	return ret;
1547 }
1548 
1549 /*
1550  * Check dma map request is within a valid iova range
1551  */
1552 static bool vfio_iommu_iova_dma_valid(struct vfio_iommu *iommu,
1553 				      dma_addr_t start, dma_addr_t end)
1554 {
1555 	struct list_head *iova = &iommu->iova_list;
1556 	struct vfio_iova *node;
1557 
1558 	list_for_each_entry(node, iova, list) {
1559 		if (start >= node->start && end <= node->end)
1560 			return true;
1561 	}
1562 
1563 	/*
1564 	 * Check for list_empty() as well since a container with
1565 	 * a single mdev device will have an empty list.
1566 	 */
1567 	return list_empty(iova);
1568 }
1569 
1570 static int vfio_dma_do_map(struct vfio_iommu *iommu,
1571 			   struct vfio_iommu_type1_dma_map *map)
1572 {
1573 	bool set_vaddr = map->flags & VFIO_DMA_MAP_FLAG_VADDR;
1574 	dma_addr_t iova = map->iova;
1575 	unsigned long vaddr = map->vaddr;
1576 	size_t size = map->size;
1577 	int ret = 0, prot = 0;
1578 	size_t pgsize;
1579 	struct vfio_dma *dma;
1580 
1581 	/* Verify that none of our __u64 fields overflow */
1582 	if (map->size != size || map->vaddr != vaddr || map->iova != iova)
1583 		return -EINVAL;
1584 
1585 	/* READ/WRITE from device perspective */
1586 	if (map->flags & VFIO_DMA_MAP_FLAG_WRITE)
1587 		prot |= IOMMU_WRITE;
1588 	if (map->flags & VFIO_DMA_MAP_FLAG_READ)
1589 		prot |= IOMMU_READ;
1590 
1591 	if ((prot && set_vaddr) || (!prot && !set_vaddr))
1592 		return -EINVAL;
1593 
1594 	mutex_lock(&iommu->lock);
1595 
1596 	pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap);
1597 
1598 	WARN_ON((pgsize - 1) & PAGE_MASK);
1599 
1600 	if (!size || (size | iova | vaddr) & (pgsize - 1)) {
1601 		ret = -EINVAL;
1602 		goto out_unlock;
1603 	}
1604 
1605 	/* Don't allow IOVA or virtual address wrap */
1606 	if (iova + size - 1 < iova || vaddr + size - 1 < vaddr) {
1607 		ret = -EINVAL;
1608 		goto out_unlock;
1609 	}
1610 
1611 	dma = vfio_find_dma(iommu, iova, size);
1612 	if (set_vaddr) {
1613 		if (!dma) {
1614 			ret = -ENOENT;
1615 		} else if (!dma->vaddr_invalid || dma->iova != iova ||
1616 			   dma->size != size) {
1617 			ret = -EINVAL;
1618 		} else {
1619 			dma->vaddr = vaddr;
1620 			dma->vaddr_invalid = false;
1621 			iommu->vaddr_invalid_count--;
1622 			wake_up_all(&iommu->vaddr_wait);
1623 		}
1624 		goto out_unlock;
1625 	} else if (dma) {
1626 		ret = -EEXIST;
1627 		goto out_unlock;
1628 	}
1629 
1630 	if (!iommu->dma_avail) {
1631 		ret = -ENOSPC;
1632 		goto out_unlock;
1633 	}
1634 
1635 	if (!vfio_iommu_iova_dma_valid(iommu, iova, iova + size - 1)) {
1636 		ret = -EINVAL;
1637 		goto out_unlock;
1638 	}
1639 
1640 	dma = kzalloc(sizeof(*dma), GFP_KERNEL);
1641 	if (!dma) {
1642 		ret = -ENOMEM;
1643 		goto out_unlock;
1644 	}
1645 
1646 	iommu->dma_avail--;
1647 	dma->iova = iova;
1648 	dma->vaddr = vaddr;
1649 	dma->prot = prot;
1650 
1651 	/*
1652 	 * We need to be able to both add to a task's locked memory and test
1653 	 * against the locked memory limit and we need to be able to do both
1654 	 * outside of this call path as pinning can be asynchronous via the
1655 	 * external interfaces for mdev devices.  RLIMIT_MEMLOCK requires a
1656 	 * task_struct and VM locked pages requires an mm_struct, however
1657 	 * holding an indefinite mm reference is not recommended, therefore we
1658 	 * only hold a reference to a task.  We could hold a reference to
1659 	 * current, however QEMU uses this call path through vCPU threads,
1660 	 * which can be killed resulting in a NULL mm and failure in the unmap
1661 	 * path when called via a different thread.  Avoid this problem by
1662 	 * using the group_leader as threads within the same group require
1663 	 * both CLONE_THREAD and CLONE_VM and will therefore use the same
1664 	 * mm_struct.
1665 	 *
1666 	 * Previously we also used the task for testing CAP_IPC_LOCK at the
1667 	 * time of pinning and accounting, however has_capability() makes use
1668 	 * of real_cred, a copy-on-write field, so we can't guarantee that it
1669 	 * matches group_leader, or in fact that it might not change by the
1670 	 * time it's evaluated.  If a process were to call MAP_DMA with
1671 	 * CAP_IPC_LOCK but later drop it, it doesn't make sense that they
1672 	 * possibly see different results for an iommu_mapped vfio_dma vs
1673 	 * externally mapped.  Therefore track CAP_IPC_LOCK in vfio_dma at the
1674 	 * time of calling MAP_DMA.
1675 	 */
1676 	get_task_struct(current->group_leader);
1677 	dma->task = current->group_leader;
1678 	dma->lock_cap = capable(CAP_IPC_LOCK);
1679 
1680 	dma->pfn_list = RB_ROOT;
1681 
1682 	/* Insert zero-sized and grow as we map chunks of it */
1683 	vfio_link_dma(iommu, dma);
1684 
1685 	/* Don't pin and map if container doesn't contain IOMMU capable domain*/
1686 	if (list_empty(&iommu->domain_list))
1687 		dma->size = size;
1688 	else
1689 		ret = vfio_pin_map_dma(iommu, dma, size);
1690 
1691 	if (!ret && iommu->dirty_page_tracking) {
1692 		ret = vfio_dma_bitmap_alloc(dma, pgsize);
1693 		if (ret)
1694 			vfio_remove_dma(iommu, dma);
1695 	}
1696 
1697 out_unlock:
1698 	mutex_unlock(&iommu->lock);
1699 	return ret;
1700 }
1701 
1702 static int vfio_iommu_replay(struct vfio_iommu *iommu,
1703 			     struct vfio_domain *domain)
1704 {
1705 	struct vfio_batch batch;
1706 	struct vfio_domain *d = NULL;
1707 	struct rb_node *n;
1708 	unsigned long limit = rlimit(RLIMIT_MEMLOCK) >> PAGE_SHIFT;
1709 	int ret;
1710 
1711 	ret = vfio_wait_all_valid(iommu);
1712 	if (ret < 0)
1713 		return ret;
1714 
1715 	/* Arbitrarily pick the first domain in the list for lookups */
1716 	if (!list_empty(&iommu->domain_list))
1717 		d = list_first_entry(&iommu->domain_list,
1718 				     struct vfio_domain, next);
1719 
1720 	vfio_batch_init(&batch);
1721 
1722 	n = rb_first(&iommu->dma_list);
1723 
1724 	for (; n; n = rb_next(n)) {
1725 		struct vfio_dma *dma;
1726 		dma_addr_t iova;
1727 
1728 		dma = rb_entry(n, struct vfio_dma, node);
1729 		iova = dma->iova;
1730 
1731 		while (iova < dma->iova + dma->size) {
1732 			phys_addr_t phys;
1733 			size_t size;
1734 
1735 			if (dma->iommu_mapped) {
1736 				phys_addr_t p;
1737 				dma_addr_t i;
1738 
1739 				if (WARN_ON(!d)) { /* mapped w/o a domain?! */
1740 					ret = -EINVAL;
1741 					goto unwind;
1742 				}
1743 
1744 				phys = iommu_iova_to_phys(d->domain, iova);
1745 
1746 				if (WARN_ON(!phys)) {
1747 					iova += PAGE_SIZE;
1748 					continue;
1749 				}
1750 
1751 				size = PAGE_SIZE;
1752 				p = phys + size;
1753 				i = iova + size;
1754 				while (i < dma->iova + dma->size &&
1755 				       p == iommu_iova_to_phys(d->domain, i)) {
1756 					size += PAGE_SIZE;
1757 					p += PAGE_SIZE;
1758 					i += PAGE_SIZE;
1759 				}
1760 			} else {
1761 				unsigned long pfn;
1762 				unsigned long vaddr = dma->vaddr +
1763 						     (iova - dma->iova);
1764 				size_t n = dma->iova + dma->size - iova;
1765 				long npage;
1766 
1767 				npage = vfio_pin_pages_remote(dma, vaddr,
1768 							      n >> PAGE_SHIFT,
1769 							      &pfn, limit,
1770 							      &batch);
1771 				if (npage <= 0) {
1772 					WARN_ON(!npage);
1773 					ret = (int)npage;
1774 					goto unwind;
1775 				}
1776 
1777 				phys = pfn << PAGE_SHIFT;
1778 				size = npage << PAGE_SHIFT;
1779 			}
1780 
1781 			ret = iommu_map(domain->domain, iova, phys,
1782 					size, dma->prot | IOMMU_CACHE);
1783 			if (ret) {
1784 				if (!dma->iommu_mapped) {
1785 					vfio_unpin_pages_remote(dma, iova,
1786 							phys >> PAGE_SHIFT,
1787 							size >> PAGE_SHIFT,
1788 							true);
1789 					vfio_batch_unpin(&batch, dma);
1790 				}
1791 				goto unwind;
1792 			}
1793 
1794 			iova += size;
1795 		}
1796 	}
1797 
1798 	/* All dmas are now mapped, defer to second tree walk for unwind */
1799 	for (n = rb_first(&iommu->dma_list); n; n = rb_next(n)) {
1800 		struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
1801 
1802 		dma->iommu_mapped = true;
1803 	}
1804 
1805 	vfio_batch_fini(&batch);
1806 	return 0;
1807 
1808 unwind:
1809 	for (; n; n = rb_prev(n)) {
1810 		struct vfio_dma *dma = rb_entry(n, struct vfio_dma, node);
1811 		dma_addr_t iova;
1812 
1813 		if (dma->iommu_mapped) {
1814 			iommu_unmap(domain->domain, dma->iova, dma->size);
1815 			continue;
1816 		}
1817 
1818 		iova = dma->iova;
1819 		while (iova < dma->iova + dma->size) {
1820 			phys_addr_t phys, p;
1821 			size_t size;
1822 			dma_addr_t i;
1823 
1824 			phys = iommu_iova_to_phys(domain->domain, iova);
1825 			if (!phys) {
1826 				iova += PAGE_SIZE;
1827 				continue;
1828 			}
1829 
1830 			size = PAGE_SIZE;
1831 			p = phys + size;
1832 			i = iova + size;
1833 			while (i < dma->iova + dma->size &&
1834 			       p == iommu_iova_to_phys(domain->domain, i)) {
1835 				size += PAGE_SIZE;
1836 				p += PAGE_SIZE;
1837 				i += PAGE_SIZE;
1838 			}
1839 
1840 			iommu_unmap(domain->domain, iova, size);
1841 			vfio_unpin_pages_remote(dma, iova, phys >> PAGE_SHIFT,
1842 						size >> PAGE_SHIFT, true);
1843 		}
1844 	}
1845 
1846 	vfio_batch_fini(&batch);
1847 	return ret;
1848 }
1849 
1850 /*
1851  * We change our unmap behavior slightly depending on whether the IOMMU
1852  * supports fine-grained superpages.  IOMMUs like AMD-Vi will use a superpage
1853  * for practically any contiguous power-of-two mapping we give it.  This means
1854  * we don't need to look for contiguous chunks ourselves to make unmapping
1855  * more efficient.  On IOMMUs with coarse-grained super pages, like Intel VT-d
1856  * with discrete 2M/1G/512G/1T superpages, identifying contiguous chunks
1857  * significantly boosts non-hugetlbfs mappings and doesn't seem to hurt when
1858  * hugetlbfs is in use.
1859  */
1860 static void vfio_test_domain_fgsp(struct vfio_domain *domain)
1861 {
1862 	struct page *pages;
1863 	int ret, order = get_order(PAGE_SIZE * 2);
1864 
1865 	pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
1866 	if (!pages)
1867 		return;
1868 
1869 	ret = iommu_map(domain->domain, 0, page_to_phys(pages), PAGE_SIZE * 2,
1870 			IOMMU_READ | IOMMU_WRITE | IOMMU_CACHE);
1871 	if (!ret) {
1872 		size_t unmapped = iommu_unmap(domain->domain, 0, PAGE_SIZE);
1873 
1874 		if (unmapped == PAGE_SIZE)
1875 			iommu_unmap(domain->domain, PAGE_SIZE, PAGE_SIZE);
1876 		else
1877 			domain->fgsp = true;
1878 	}
1879 
1880 	__free_pages(pages, order);
1881 }
1882 
1883 static struct vfio_iommu_group *find_iommu_group(struct vfio_domain *domain,
1884 						 struct iommu_group *iommu_group)
1885 {
1886 	struct vfio_iommu_group *g;
1887 
1888 	list_for_each_entry(g, &domain->group_list, next) {
1889 		if (g->iommu_group == iommu_group)
1890 			return g;
1891 	}
1892 
1893 	return NULL;
1894 }
1895 
1896 static struct vfio_iommu_group*
1897 vfio_iommu_find_iommu_group(struct vfio_iommu *iommu,
1898 			    struct iommu_group *iommu_group)
1899 {
1900 	struct vfio_iommu_group *group;
1901 	struct vfio_domain *domain;
1902 
1903 	list_for_each_entry(domain, &iommu->domain_list, next) {
1904 		group = find_iommu_group(domain, iommu_group);
1905 		if (group)
1906 			return group;
1907 	}
1908 
1909 	list_for_each_entry(group, &iommu->emulated_iommu_groups, next)
1910 		if (group->iommu_group == iommu_group)
1911 			return group;
1912 	return NULL;
1913 }
1914 
1915 static bool vfio_iommu_has_sw_msi(struct list_head *group_resv_regions,
1916 				  phys_addr_t *base)
1917 {
1918 	struct iommu_resv_region *region;
1919 	bool ret = false;
1920 
1921 	list_for_each_entry(region, group_resv_regions, list) {
1922 		/*
1923 		 * The presence of any 'real' MSI regions should take
1924 		 * precedence over the software-managed one if the
1925 		 * IOMMU driver happens to advertise both types.
1926 		 */
1927 		if (region->type == IOMMU_RESV_MSI) {
1928 			ret = false;
1929 			break;
1930 		}
1931 
1932 		if (region->type == IOMMU_RESV_SW_MSI) {
1933 			*base = region->start;
1934 			ret = true;
1935 		}
1936 	}
1937 
1938 	return ret;
1939 }
1940 
1941 /*
1942  * This is a helper function to insert an address range to iova list.
1943  * The list is initially created with a single entry corresponding to
1944  * the IOMMU domain geometry to which the device group is attached.
1945  * The list aperture gets modified when a new domain is added to the
1946  * container if the new aperture doesn't conflict with the current one
1947  * or with any existing dma mappings. The list is also modified to
1948  * exclude any reserved regions associated with the device group.
1949  */
1950 static int vfio_iommu_iova_insert(struct list_head *head,
1951 				  dma_addr_t start, dma_addr_t end)
1952 {
1953 	struct vfio_iova *region;
1954 
1955 	region = kmalloc(sizeof(*region), GFP_KERNEL);
1956 	if (!region)
1957 		return -ENOMEM;
1958 
1959 	INIT_LIST_HEAD(&region->list);
1960 	region->start = start;
1961 	region->end = end;
1962 
1963 	list_add_tail(&region->list, head);
1964 	return 0;
1965 }
1966 
1967 /*
1968  * Check the new iommu aperture conflicts with existing aper or with any
1969  * existing dma mappings.
1970  */
1971 static bool vfio_iommu_aper_conflict(struct vfio_iommu *iommu,
1972 				     dma_addr_t start, dma_addr_t end)
1973 {
1974 	struct vfio_iova *first, *last;
1975 	struct list_head *iova = &iommu->iova_list;
1976 
1977 	if (list_empty(iova))
1978 		return false;
1979 
1980 	/* Disjoint sets, return conflict */
1981 	first = list_first_entry(iova, struct vfio_iova, list);
1982 	last = list_last_entry(iova, struct vfio_iova, list);
1983 	if (start > last->end || end < first->start)
1984 		return true;
1985 
1986 	/* Check for any existing dma mappings below the new start */
1987 	if (start > first->start) {
1988 		if (vfio_find_dma(iommu, first->start, start - first->start))
1989 			return true;
1990 	}
1991 
1992 	/* Check for any existing dma mappings beyond the new end */
1993 	if (end < last->end) {
1994 		if (vfio_find_dma(iommu, end + 1, last->end - end))
1995 			return true;
1996 	}
1997 
1998 	return false;
1999 }
2000 
2001 /*
2002  * Resize iommu iova aperture window. This is called only if the new
2003  * aperture has no conflict with existing aperture and dma mappings.
2004  */
2005 static int vfio_iommu_aper_resize(struct list_head *iova,
2006 				  dma_addr_t start, dma_addr_t end)
2007 {
2008 	struct vfio_iova *node, *next;
2009 
2010 	if (list_empty(iova))
2011 		return vfio_iommu_iova_insert(iova, start, end);
2012 
2013 	/* Adjust iova list start */
2014 	list_for_each_entry_safe(node, next, iova, list) {
2015 		if (start < node->start)
2016 			break;
2017 		if (start >= node->start && start < node->end) {
2018 			node->start = start;
2019 			break;
2020 		}
2021 		/* Delete nodes before new start */
2022 		list_del(&node->list);
2023 		kfree(node);
2024 	}
2025 
2026 	/* Adjust iova list end */
2027 	list_for_each_entry_safe(node, next, iova, list) {
2028 		if (end > node->end)
2029 			continue;
2030 		if (end > node->start && end <= node->end) {
2031 			node->end = end;
2032 			continue;
2033 		}
2034 		/* Delete nodes after new end */
2035 		list_del(&node->list);
2036 		kfree(node);
2037 	}
2038 
2039 	return 0;
2040 }
2041 
2042 /*
2043  * Check reserved region conflicts with existing dma mappings
2044  */
2045 static bool vfio_iommu_resv_conflict(struct vfio_iommu *iommu,
2046 				     struct list_head *resv_regions)
2047 {
2048 	struct iommu_resv_region *region;
2049 
2050 	/* Check for conflict with existing dma mappings */
2051 	list_for_each_entry(region, resv_regions, list) {
2052 		if (region->type == IOMMU_RESV_DIRECT_RELAXABLE)
2053 			continue;
2054 
2055 		if (vfio_find_dma(iommu, region->start, region->length))
2056 			return true;
2057 	}
2058 
2059 	return false;
2060 }
2061 
2062 /*
2063  * Check iova region overlap with  reserved regions and
2064  * exclude them from the iommu iova range
2065  */
2066 static int vfio_iommu_resv_exclude(struct list_head *iova,
2067 				   struct list_head *resv_regions)
2068 {
2069 	struct iommu_resv_region *resv;
2070 	struct vfio_iova *n, *next;
2071 
2072 	list_for_each_entry(resv, resv_regions, list) {
2073 		phys_addr_t start, end;
2074 
2075 		if (resv->type == IOMMU_RESV_DIRECT_RELAXABLE)
2076 			continue;
2077 
2078 		start = resv->start;
2079 		end = resv->start + resv->length - 1;
2080 
2081 		list_for_each_entry_safe(n, next, iova, list) {
2082 			int ret = 0;
2083 
2084 			/* No overlap */
2085 			if (start > n->end || end < n->start)
2086 				continue;
2087 			/*
2088 			 * Insert a new node if current node overlaps with the
2089 			 * reserve region to exclude that from valid iova range.
2090 			 * Note that, new node is inserted before the current
2091 			 * node and finally the current node is deleted keeping
2092 			 * the list updated and sorted.
2093 			 */
2094 			if (start > n->start)
2095 				ret = vfio_iommu_iova_insert(&n->list, n->start,
2096 							     start - 1);
2097 			if (!ret && end < n->end)
2098 				ret = vfio_iommu_iova_insert(&n->list, end + 1,
2099 							     n->end);
2100 			if (ret)
2101 				return ret;
2102 
2103 			list_del(&n->list);
2104 			kfree(n);
2105 		}
2106 	}
2107 
2108 	if (list_empty(iova))
2109 		return -EINVAL;
2110 
2111 	return 0;
2112 }
2113 
2114 static void vfio_iommu_resv_free(struct list_head *resv_regions)
2115 {
2116 	struct iommu_resv_region *n, *next;
2117 
2118 	list_for_each_entry_safe(n, next, resv_regions, list) {
2119 		list_del(&n->list);
2120 		kfree(n);
2121 	}
2122 }
2123 
2124 static void vfio_iommu_iova_free(struct list_head *iova)
2125 {
2126 	struct vfio_iova *n, *next;
2127 
2128 	list_for_each_entry_safe(n, next, iova, list) {
2129 		list_del(&n->list);
2130 		kfree(n);
2131 	}
2132 }
2133 
2134 static int vfio_iommu_iova_get_copy(struct vfio_iommu *iommu,
2135 				    struct list_head *iova_copy)
2136 {
2137 	struct list_head *iova = &iommu->iova_list;
2138 	struct vfio_iova *n;
2139 	int ret;
2140 
2141 	list_for_each_entry(n, iova, list) {
2142 		ret = vfio_iommu_iova_insert(iova_copy, n->start, n->end);
2143 		if (ret)
2144 			goto out_free;
2145 	}
2146 
2147 	return 0;
2148 
2149 out_free:
2150 	vfio_iommu_iova_free(iova_copy);
2151 	return ret;
2152 }
2153 
2154 static void vfio_iommu_iova_insert_copy(struct vfio_iommu *iommu,
2155 					struct list_head *iova_copy)
2156 {
2157 	struct list_head *iova = &iommu->iova_list;
2158 
2159 	vfio_iommu_iova_free(iova);
2160 
2161 	list_splice_tail(iova_copy, iova);
2162 }
2163 
2164 /* Redundantly walks non-present capabilities to simplify caller */
2165 static int vfio_iommu_device_capable(struct device *dev, void *data)
2166 {
2167 	return device_iommu_capable(dev, (enum iommu_cap)data);
2168 }
2169 
2170 static int vfio_iommu_domain_alloc(struct device *dev, void *data)
2171 {
2172 	struct iommu_domain **domain = data;
2173 
2174 	*domain = iommu_domain_alloc(dev->bus);
2175 	return 1; /* Don't iterate */
2176 }
2177 
2178 static int vfio_iommu_type1_attach_group(void *iommu_data,
2179 		struct iommu_group *iommu_group, enum vfio_group_type type)
2180 {
2181 	struct vfio_iommu *iommu = iommu_data;
2182 	struct vfio_iommu_group *group;
2183 	struct vfio_domain *domain, *d;
2184 	bool resv_msi, msi_remap;
2185 	phys_addr_t resv_msi_base = 0;
2186 	struct iommu_domain_geometry *geo;
2187 	LIST_HEAD(iova_copy);
2188 	LIST_HEAD(group_resv_regions);
2189 	int ret = -EINVAL;
2190 
2191 	mutex_lock(&iommu->lock);
2192 
2193 	/* Check for duplicates */
2194 	if (vfio_iommu_find_iommu_group(iommu, iommu_group))
2195 		goto out_unlock;
2196 
2197 	ret = -ENOMEM;
2198 	group = kzalloc(sizeof(*group), GFP_KERNEL);
2199 	if (!group)
2200 		goto out_unlock;
2201 	group->iommu_group = iommu_group;
2202 
2203 	if (type == VFIO_EMULATED_IOMMU) {
2204 		list_add(&group->next, &iommu->emulated_iommu_groups);
2205 		/*
2206 		 * An emulated IOMMU group cannot dirty memory directly, it can
2207 		 * only use interfaces that provide dirty tracking.
2208 		 * The iommu scope can only be promoted with the addition of a
2209 		 * dirty tracking group.
2210 		 */
2211 		group->pinned_page_dirty_scope = true;
2212 		ret = 0;
2213 		goto out_unlock;
2214 	}
2215 
2216 	ret = -ENOMEM;
2217 	domain = kzalloc(sizeof(*domain), GFP_KERNEL);
2218 	if (!domain)
2219 		goto out_free_group;
2220 
2221 	/*
2222 	 * Going via the iommu_group iterator avoids races, and trivially gives
2223 	 * us a representative device for the IOMMU API call. We don't actually
2224 	 * want to iterate beyond the first device (if any).
2225 	 */
2226 	ret = -EIO;
2227 	iommu_group_for_each_dev(iommu_group, &domain->domain,
2228 				 vfio_iommu_domain_alloc);
2229 	if (!domain->domain)
2230 		goto out_free_domain;
2231 
2232 	if (iommu->nesting) {
2233 		ret = iommu_enable_nesting(domain->domain);
2234 		if (ret)
2235 			goto out_domain;
2236 	}
2237 
2238 	ret = iommu_attach_group(domain->domain, group->iommu_group);
2239 	if (ret)
2240 		goto out_domain;
2241 
2242 	/* Get aperture info */
2243 	geo = &domain->domain->geometry;
2244 	if (vfio_iommu_aper_conflict(iommu, geo->aperture_start,
2245 				     geo->aperture_end)) {
2246 		ret = -EINVAL;
2247 		goto out_detach;
2248 	}
2249 
2250 	ret = iommu_get_group_resv_regions(iommu_group, &group_resv_regions);
2251 	if (ret)
2252 		goto out_detach;
2253 
2254 	if (vfio_iommu_resv_conflict(iommu, &group_resv_regions)) {
2255 		ret = -EINVAL;
2256 		goto out_detach;
2257 	}
2258 
2259 	/*
2260 	 * We don't want to work on the original iova list as the list
2261 	 * gets modified and in case of failure we have to retain the
2262 	 * original list. Get a copy here.
2263 	 */
2264 	ret = vfio_iommu_iova_get_copy(iommu, &iova_copy);
2265 	if (ret)
2266 		goto out_detach;
2267 
2268 	ret = vfio_iommu_aper_resize(&iova_copy, geo->aperture_start,
2269 				     geo->aperture_end);
2270 	if (ret)
2271 		goto out_detach;
2272 
2273 	ret = vfio_iommu_resv_exclude(&iova_copy, &group_resv_regions);
2274 	if (ret)
2275 		goto out_detach;
2276 
2277 	resv_msi = vfio_iommu_has_sw_msi(&group_resv_regions, &resv_msi_base);
2278 
2279 	INIT_LIST_HEAD(&domain->group_list);
2280 	list_add(&group->next, &domain->group_list);
2281 
2282 	msi_remap = irq_domain_check_msi_remap() ||
2283 		    iommu_group_for_each_dev(iommu_group, (void *)IOMMU_CAP_INTR_REMAP,
2284 					     vfio_iommu_device_capable);
2285 
2286 	if (!allow_unsafe_interrupts && !msi_remap) {
2287 		pr_warn("%s: No interrupt remapping support.  Use the module param \"allow_unsafe_interrupts\" to enable VFIO IOMMU support on this platform\n",
2288 		       __func__);
2289 		ret = -EPERM;
2290 		goto out_detach;
2291 	}
2292 
2293 	/*
2294 	 * If the IOMMU can block non-coherent operations (ie PCIe TLPs with
2295 	 * no-snoop set) then VFIO always turns this feature on because on Intel
2296 	 * platforms it optimizes KVM to disable wbinvd emulation.
2297 	 */
2298 	if (domain->domain->ops->enforce_cache_coherency)
2299 		domain->enforce_cache_coherency =
2300 			domain->domain->ops->enforce_cache_coherency(
2301 				domain->domain);
2302 
2303 	/*
2304 	 * Try to match an existing compatible domain.  We don't want to
2305 	 * preclude an IOMMU driver supporting multiple bus_types and being
2306 	 * able to include different bus_types in the same IOMMU domain, so
2307 	 * we test whether the domains use the same iommu_ops rather than
2308 	 * testing if they're on the same bus_type.
2309 	 */
2310 	list_for_each_entry(d, &iommu->domain_list, next) {
2311 		if (d->domain->ops == domain->domain->ops &&
2312 		    d->enforce_cache_coherency ==
2313 			    domain->enforce_cache_coherency) {
2314 			iommu_detach_group(domain->domain, group->iommu_group);
2315 			if (!iommu_attach_group(d->domain,
2316 						group->iommu_group)) {
2317 				list_add(&group->next, &d->group_list);
2318 				iommu_domain_free(domain->domain);
2319 				kfree(domain);
2320 				goto done;
2321 			}
2322 
2323 			ret = iommu_attach_group(domain->domain,
2324 						 group->iommu_group);
2325 			if (ret)
2326 				goto out_domain;
2327 		}
2328 	}
2329 
2330 	vfio_test_domain_fgsp(domain);
2331 
2332 	/* replay mappings on new domains */
2333 	ret = vfio_iommu_replay(iommu, domain);
2334 	if (ret)
2335 		goto out_detach;
2336 
2337 	if (resv_msi) {
2338 		ret = iommu_get_msi_cookie(domain->domain, resv_msi_base);
2339 		if (ret && ret != -ENODEV)
2340 			goto out_detach;
2341 	}
2342 
2343 	list_add(&domain->next, &iommu->domain_list);
2344 	vfio_update_pgsize_bitmap(iommu);
2345 done:
2346 	/* Delete the old one and insert new iova list */
2347 	vfio_iommu_iova_insert_copy(iommu, &iova_copy);
2348 
2349 	/*
2350 	 * An iommu backed group can dirty memory directly and therefore
2351 	 * demotes the iommu scope until it declares itself dirty tracking
2352 	 * capable via the page pinning interface.
2353 	 */
2354 	iommu->num_non_pinned_groups++;
2355 	mutex_unlock(&iommu->lock);
2356 	vfio_iommu_resv_free(&group_resv_regions);
2357 
2358 	return 0;
2359 
2360 out_detach:
2361 	iommu_detach_group(domain->domain, group->iommu_group);
2362 out_domain:
2363 	iommu_domain_free(domain->domain);
2364 	vfio_iommu_iova_free(&iova_copy);
2365 	vfio_iommu_resv_free(&group_resv_regions);
2366 out_free_domain:
2367 	kfree(domain);
2368 out_free_group:
2369 	kfree(group);
2370 out_unlock:
2371 	mutex_unlock(&iommu->lock);
2372 	return ret;
2373 }
2374 
2375 static void vfio_iommu_unmap_unpin_all(struct vfio_iommu *iommu)
2376 {
2377 	struct rb_node *node;
2378 
2379 	while ((node = rb_first(&iommu->dma_list)))
2380 		vfio_remove_dma(iommu, rb_entry(node, struct vfio_dma, node));
2381 }
2382 
2383 static void vfio_iommu_unmap_unpin_reaccount(struct vfio_iommu *iommu)
2384 {
2385 	struct rb_node *n, *p;
2386 
2387 	n = rb_first(&iommu->dma_list);
2388 	for (; n; n = rb_next(n)) {
2389 		struct vfio_dma *dma;
2390 		long locked = 0, unlocked = 0;
2391 
2392 		dma = rb_entry(n, struct vfio_dma, node);
2393 		unlocked += vfio_unmap_unpin(iommu, dma, false);
2394 		p = rb_first(&dma->pfn_list);
2395 		for (; p; p = rb_next(p)) {
2396 			struct vfio_pfn *vpfn = rb_entry(p, struct vfio_pfn,
2397 							 node);
2398 
2399 			if (!is_invalid_reserved_pfn(vpfn->pfn))
2400 				locked++;
2401 		}
2402 		vfio_lock_acct(dma, locked - unlocked, true);
2403 	}
2404 }
2405 
2406 /*
2407  * Called when a domain is removed in detach. It is possible that
2408  * the removed domain decided the iova aperture window. Modify the
2409  * iova aperture with the smallest window among existing domains.
2410  */
2411 static void vfio_iommu_aper_expand(struct vfio_iommu *iommu,
2412 				   struct list_head *iova_copy)
2413 {
2414 	struct vfio_domain *domain;
2415 	struct vfio_iova *node;
2416 	dma_addr_t start = 0;
2417 	dma_addr_t end = (dma_addr_t)~0;
2418 
2419 	if (list_empty(iova_copy))
2420 		return;
2421 
2422 	list_for_each_entry(domain, &iommu->domain_list, next) {
2423 		struct iommu_domain_geometry *geo = &domain->domain->geometry;
2424 
2425 		if (geo->aperture_start > start)
2426 			start = geo->aperture_start;
2427 		if (geo->aperture_end < end)
2428 			end = geo->aperture_end;
2429 	}
2430 
2431 	/* Modify aperture limits. The new aper is either same or bigger */
2432 	node = list_first_entry(iova_copy, struct vfio_iova, list);
2433 	node->start = start;
2434 	node = list_last_entry(iova_copy, struct vfio_iova, list);
2435 	node->end = end;
2436 }
2437 
2438 /*
2439  * Called when a group is detached. The reserved regions for that
2440  * group can be part of valid iova now. But since reserved regions
2441  * may be duplicated among groups, populate the iova valid regions
2442  * list again.
2443  */
2444 static int vfio_iommu_resv_refresh(struct vfio_iommu *iommu,
2445 				   struct list_head *iova_copy)
2446 {
2447 	struct vfio_domain *d;
2448 	struct vfio_iommu_group *g;
2449 	struct vfio_iova *node;
2450 	dma_addr_t start, end;
2451 	LIST_HEAD(resv_regions);
2452 	int ret;
2453 
2454 	if (list_empty(iova_copy))
2455 		return -EINVAL;
2456 
2457 	list_for_each_entry(d, &iommu->domain_list, next) {
2458 		list_for_each_entry(g, &d->group_list, next) {
2459 			ret = iommu_get_group_resv_regions(g->iommu_group,
2460 							   &resv_regions);
2461 			if (ret)
2462 				goto done;
2463 		}
2464 	}
2465 
2466 	node = list_first_entry(iova_copy, struct vfio_iova, list);
2467 	start = node->start;
2468 	node = list_last_entry(iova_copy, struct vfio_iova, list);
2469 	end = node->end;
2470 
2471 	/* purge the iova list and create new one */
2472 	vfio_iommu_iova_free(iova_copy);
2473 
2474 	ret = vfio_iommu_aper_resize(iova_copy, start, end);
2475 	if (ret)
2476 		goto done;
2477 
2478 	/* Exclude current reserved regions from iova ranges */
2479 	ret = vfio_iommu_resv_exclude(iova_copy, &resv_regions);
2480 done:
2481 	vfio_iommu_resv_free(&resv_regions);
2482 	return ret;
2483 }
2484 
2485 static void vfio_iommu_type1_detach_group(void *iommu_data,
2486 					  struct iommu_group *iommu_group)
2487 {
2488 	struct vfio_iommu *iommu = iommu_data;
2489 	struct vfio_domain *domain;
2490 	struct vfio_iommu_group *group;
2491 	bool update_dirty_scope = false;
2492 	LIST_HEAD(iova_copy);
2493 
2494 	mutex_lock(&iommu->lock);
2495 	list_for_each_entry(group, &iommu->emulated_iommu_groups, next) {
2496 		if (group->iommu_group != iommu_group)
2497 			continue;
2498 		update_dirty_scope = !group->pinned_page_dirty_scope;
2499 		list_del(&group->next);
2500 		kfree(group);
2501 
2502 		if (list_empty(&iommu->emulated_iommu_groups) &&
2503 		    list_empty(&iommu->domain_list)) {
2504 			WARN_ON(!list_empty(&iommu->device_list));
2505 			vfio_iommu_unmap_unpin_all(iommu);
2506 		}
2507 		goto detach_group_done;
2508 	}
2509 
2510 	/*
2511 	 * Get a copy of iova list. This will be used to update
2512 	 * and to replace the current one later. Please note that
2513 	 * we will leave the original list as it is if update fails.
2514 	 */
2515 	vfio_iommu_iova_get_copy(iommu, &iova_copy);
2516 
2517 	list_for_each_entry(domain, &iommu->domain_list, next) {
2518 		group = find_iommu_group(domain, iommu_group);
2519 		if (!group)
2520 			continue;
2521 
2522 		iommu_detach_group(domain->domain, group->iommu_group);
2523 		update_dirty_scope = !group->pinned_page_dirty_scope;
2524 		list_del(&group->next);
2525 		kfree(group);
2526 		/*
2527 		 * Group ownership provides privilege, if the group list is
2528 		 * empty, the domain goes away. If it's the last domain with
2529 		 * iommu and external domain doesn't exist, then all the
2530 		 * mappings go away too. If it's the last domain with iommu and
2531 		 * external domain exist, update accounting
2532 		 */
2533 		if (list_empty(&domain->group_list)) {
2534 			if (list_is_singular(&iommu->domain_list)) {
2535 				if (list_empty(&iommu->emulated_iommu_groups)) {
2536 					WARN_ON(!list_empty(
2537 						&iommu->device_list));
2538 					vfio_iommu_unmap_unpin_all(iommu);
2539 				} else {
2540 					vfio_iommu_unmap_unpin_reaccount(iommu);
2541 				}
2542 			}
2543 			iommu_domain_free(domain->domain);
2544 			list_del(&domain->next);
2545 			kfree(domain);
2546 			vfio_iommu_aper_expand(iommu, &iova_copy);
2547 			vfio_update_pgsize_bitmap(iommu);
2548 		}
2549 		break;
2550 	}
2551 
2552 	if (!vfio_iommu_resv_refresh(iommu, &iova_copy))
2553 		vfio_iommu_iova_insert_copy(iommu, &iova_copy);
2554 	else
2555 		vfio_iommu_iova_free(&iova_copy);
2556 
2557 detach_group_done:
2558 	/*
2559 	 * Removal of a group without dirty tracking may allow the iommu scope
2560 	 * to be promoted.
2561 	 */
2562 	if (update_dirty_scope) {
2563 		iommu->num_non_pinned_groups--;
2564 		if (iommu->dirty_page_tracking)
2565 			vfio_iommu_populate_bitmap_full(iommu);
2566 	}
2567 	mutex_unlock(&iommu->lock);
2568 }
2569 
2570 static void *vfio_iommu_type1_open(unsigned long arg)
2571 {
2572 	struct vfio_iommu *iommu;
2573 
2574 	iommu = kzalloc(sizeof(*iommu), GFP_KERNEL);
2575 	if (!iommu)
2576 		return ERR_PTR(-ENOMEM);
2577 
2578 	switch (arg) {
2579 	case VFIO_TYPE1_IOMMU:
2580 		break;
2581 	case VFIO_TYPE1_NESTING_IOMMU:
2582 		iommu->nesting = true;
2583 		fallthrough;
2584 	case VFIO_TYPE1v2_IOMMU:
2585 		iommu->v2 = true;
2586 		break;
2587 	default:
2588 		kfree(iommu);
2589 		return ERR_PTR(-EINVAL);
2590 	}
2591 
2592 	INIT_LIST_HEAD(&iommu->domain_list);
2593 	INIT_LIST_HEAD(&iommu->iova_list);
2594 	iommu->dma_list = RB_ROOT;
2595 	iommu->dma_avail = dma_entry_limit;
2596 	iommu->container_open = true;
2597 	mutex_init(&iommu->lock);
2598 	mutex_init(&iommu->device_list_lock);
2599 	INIT_LIST_HEAD(&iommu->device_list);
2600 	init_waitqueue_head(&iommu->vaddr_wait);
2601 	iommu->pgsize_bitmap = PAGE_MASK;
2602 	INIT_LIST_HEAD(&iommu->emulated_iommu_groups);
2603 
2604 	return iommu;
2605 }
2606 
2607 static void vfio_release_domain(struct vfio_domain *domain)
2608 {
2609 	struct vfio_iommu_group *group, *group_tmp;
2610 
2611 	list_for_each_entry_safe(group, group_tmp,
2612 				 &domain->group_list, next) {
2613 		iommu_detach_group(domain->domain, group->iommu_group);
2614 		list_del(&group->next);
2615 		kfree(group);
2616 	}
2617 
2618 	iommu_domain_free(domain->domain);
2619 }
2620 
2621 static void vfio_iommu_type1_release(void *iommu_data)
2622 {
2623 	struct vfio_iommu *iommu = iommu_data;
2624 	struct vfio_domain *domain, *domain_tmp;
2625 	struct vfio_iommu_group *group, *next_group;
2626 
2627 	list_for_each_entry_safe(group, next_group,
2628 			&iommu->emulated_iommu_groups, next) {
2629 		list_del(&group->next);
2630 		kfree(group);
2631 	}
2632 
2633 	vfio_iommu_unmap_unpin_all(iommu);
2634 
2635 	list_for_each_entry_safe(domain, domain_tmp,
2636 				 &iommu->domain_list, next) {
2637 		vfio_release_domain(domain);
2638 		list_del(&domain->next);
2639 		kfree(domain);
2640 	}
2641 
2642 	vfio_iommu_iova_free(&iommu->iova_list);
2643 
2644 	kfree(iommu);
2645 }
2646 
2647 static int vfio_domains_have_enforce_cache_coherency(struct vfio_iommu *iommu)
2648 {
2649 	struct vfio_domain *domain;
2650 	int ret = 1;
2651 
2652 	mutex_lock(&iommu->lock);
2653 	list_for_each_entry(domain, &iommu->domain_list, next) {
2654 		if (!(domain->enforce_cache_coherency)) {
2655 			ret = 0;
2656 			break;
2657 		}
2658 	}
2659 	mutex_unlock(&iommu->lock);
2660 
2661 	return ret;
2662 }
2663 
2664 static int vfio_iommu_type1_check_extension(struct vfio_iommu *iommu,
2665 					    unsigned long arg)
2666 {
2667 	switch (arg) {
2668 	case VFIO_TYPE1_IOMMU:
2669 	case VFIO_TYPE1v2_IOMMU:
2670 	case VFIO_TYPE1_NESTING_IOMMU:
2671 	case VFIO_UNMAP_ALL:
2672 	case VFIO_UPDATE_VADDR:
2673 		return 1;
2674 	case VFIO_DMA_CC_IOMMU:
2675 		if (!iommu)
2676 			return 0;
2677 		return vfio_domains_have_enforce_cache_coherency(iommu);
2678 	default:
2679 		return 0;
2680 	}
2681 }
2682 
2683 static int vfio_iommu_iova_add_cap(struct vfio_info_cap *caps,
2684 		 struct vfio_iommu_type1_info_cap_iova_range *cap_iovas,
2685 		 size_t size)
2686 {
2687 	struct vfio_info_cap_header *header;
2688 	struct vfio_iommu_type1_info_cap_iova_range *iova_cap;
2689 
2690 	header = vfio_info_cap_add(caps, size,
2691 				   VFIO_IOMMU_TYPE1_INFO_CAP_IOVA_RANGE, 1);
2692 	if (IS_ERR(header))
2693 		return PTR_ERR(header);
2694 
2695 	iova_cap = container_of(header,
2696 				struct vfio_iommu_type1_info_cap_iova_range,
2697 				header);
2698 	iova_cap->nr_iovas = cap_iovas->nr_iovas;
2699 	memcpy(iova_cap->iova_ranges, cap_iovas->iova_ranges,
2700 	       cap_iovas->nr_iovas * sizeof(*cap_iovas->iova_ranges));
2701 	return 0;
2702 }
2703 
2704 static int vfio_iommu_iova_build_caps(struct vfio_iommu *iommu,
2705 				      struct vfio_info_cap *caps)
2706 {
2707 	struct vfio_iommu_type1_info_cap_iova_range *cap_iovas;
2708 	struct vfio_iova *iova;
2709 	size_t size;
2710 	int iovas = 0, i = 0, ret;
2711 
2712 	list_for_each_entry(iova, &iommu->iova_list, list)
2713 		iovas++;
2714 
2715 	if (!iovas) {
2716 		/*
2717 		 * Return 0 as a container with a single mdev device
2718 		 * will have an empty list
2719 		 */
2720 		return 0;
2721 	}
2722 
2723 	size = struct_size(cap_iovas, iova_ranges, iovas);
2724 
2725 	cap_iovas = kzalloc(size, GFP_KERNEL);
2726 	if (!cap_iovas)
2727 		return -ENOMEM;
2728 
2729 	cap_iovas->nr_iovas = iovas;
2730 
2731 	list_for_each_entry(iova, &iommu->iova_list, list) {
2732 		cap_iovas->iova_ranges[i].start = iova->start;
2733 		cap_iovas->iova_ranges[i].end = iova->end;
2734 		i++;
2735 	}
2736 
2737 	ret = vfio_iommu_iova_add_cap(caps, cap_iovas, size);
2738 
2739 	kfree(cap_iovas);
2740 	return ret;
2741 }
2742 
2743 static int vfio_iommu_migration_build_caps(struct vfio_iommu *iommu,
2744 					   struct vfio_info_cap *caps)
2745 {
2746 	struct vfio_iommu_type1_info_cap_migration cap_mig;
2747 
2748 	cap_mig.header.id = VFIO_IOMMU_TYPE1_INFO_CAP_MIGRATION;
2749 	cap_mig.header.version = 1;
2750 
2751 	cap_mig.flags = 0;
2752 	/* support minimum pgsize */
2753 	cap_mig.pgsize_bitmap = (size_t)1 << __ffs(iommu->pgsize_bitmap);
2754 	cap_mig.max_dirty_bitmap_size = DIRTY_BITMAP_SIZE_MAX;
2755 
2756 	return vfio_info_add_capability(caps, &cap_mig.header, sizeof(cap_mig));
2757 }
2758 
2759 static int vfio_iommu_dma_avail_build_caps(struct vfio_iommu *iommu,
2760 					   struct vfio_info_cap *caps)
2761 {
2762 	struct vfio_iommu_type1_info_dma_avail cap_dma_avail;
2763 
2764 	cap_dma_avail.header.id = VFIO_IOMMU_TYPE1_INFO_DMA_AVAIL;
2765 	cap_dma_avail.header.version = 1;
2766 
2767 	cap_dma_avail.avail = iommu->dma_avail;
2768 
2769 	return vfio_info_add_capability(caps, &cap_dma_avail.header,
2770 					sizeof(cap_dma_avail));
2771 }
2772 
2773 static int vfio_iommu_type1_get_info(struct vfio_iommu *iommu,
2774 				     unsigned long arg)
2775 {
2776 	struct vfio_iommu_type1_info info;
2777 	unsigned long minsz;
2778 	struct vfio_info_cap caps = { .buf = NULL, .size = 0 };
2779 	unsigned long capsz;
2780 	int ret;
2781 
2782 	minsz = offsetofend(struct vfio_iommu_type1_info, iova_pgsizes);
2783 
2784 	/* For backward compatibility, cannot require this */
2785 	capsz = offsetofend(struct vfio_iommu_type1_info, cap_offset);
2786 
2787 	if (copy_from_user(&info, (void __user *)arg, minsz))
2788 		return -EFAULT;
2789 
2790 	if (info.argsz < minsz)
2791 		return -EINVAL;
2792 
2793 	if (info.argsz >= capsz) {
2794 		minsz = capsz;
2795 		info.cap_offset = 0; /* output, no-recopy necessary */
2796 	}
2797 
2798 	mutex_lock(&iommu->lock);
2799 	info.flags = VFIO_IOMMU_INFO_PGSIZES;
2800 
2801 	info.iova_pgsizes = iommu->pgsize_bitmap;
2802 
2803 	ret = vfio_iommu_migration_build_caps(iommu, &caps);
2804 
2805 	if (!ret)
2806 		ret = vfio_iommu_dma_avail_build_caps(iommu, &caps);
2807 
2808 	if (!ret)
2809 		ret = vfio_iommu_iova_build_caps(iommu, &caps);
2810 
2811 	mutex_unlock(&iommu->lock);
2812 
2813 	if (ret)
2814 		return ret;
2815 
2816 	if (caps.size) {
2817 		info.flags |= VFIO_IOMMU_INFO_CAPS;
2818 
2819 		if (info.argsz < sizeof(info) + caps.size) {
2820 			info.argsz = sizeof(info) + caps.size;
2821 		} else {
2822 			vfio_info_cap_shift(&caps, sizeof(info));
2823 			if (copy_to_user((void __user *)arg +
2824 					sizeof(info), caps.buf,
2825 					caps.size)) {
2826 				kfree(caps.buf);
2827 				return -EFAULT;
2828 			}
2829 			info.cap_offset = sizeof(info);
2830 		}
2831 
2832 		kfree(caps.buf);
2833 	}
2834 
2835 	return copy_to_user((void __user *)arg, &info, minsz) ?
2836 			-EFAULT : 0;
2837 }
2838 
2839 static int vfio_iommu_type1_map_dma(struct vfio_iommu *iommu,
2840 				    unsigned long arg)
2841 {
2842 	struct vfio_iommu_type1_dma_map map;
2843 	unsigned long minsz;
2844 	uint32_t mask = VFIO_DMA_MAP_FLAG_READ | VFIO_DMA_MAP_FLAG_WRITE |
2845 			VFIO_DMA_MAP_FLAG_VADDR;
2846 
2847 	minsz = offsetofend(struct vfio_iommu_type1_dma_map, size);
2848 
2849 	if (copy_from_user(&map, (void __user *)arg, minsz))
2850 		return -EFAULT;
2851 
2852 	if (map.argsz < minsz || map.flags & ~mask)
2853 		return -EINVAL;
2854 
2855 	return vfio_dma_do_map(iommu, &map);
2856 }
2857 
2858 static int vfio_iommu_type1_unmap_dma(struct vfio_iommu *iommu,
2859 				      unsigned long arg)
2860 {
2861 	struct vfio_iommu_type1_dma_unmap unmap;
2862 	struct vfio_bitmap bitmap = { 0 };
2863 	uint32_t mask = VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP |
2864 			VFIO_DMA_UNMAP_FLAG_VADDR |
2865 			VFIO_DMA_UNMAP_FLAG_ALL;
2866 	unsigned long minsz;
2867 	int ret;
2868 
2869 	minsz = offsetofend(struct vfio_iommu_type1_dma_unmap, size);
2870 
2871 	if (copy_from_user(&unmap, (void __user *)arg, minsz))
2872 		return -EFAULT;
2873 
2874 	if (unmap.argsz < minsz || unmap.flags & ~mask)
2875 		return -EINVAL;
2876 
2877 	if ((unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) &&
2878 	    (unmap.flags & (VFIO_DMA_UNMAP_FLAG_ALL |
2879 			    VFIO_DMA_UNMAP_FLAG_VADDR)))
2880 		return -EINVAL;
2881 
2882 	if (unmap.flags & VFIO_DMA_UNMAP_FLAG_GET_DIRTY_BITMAP) {
2883 		unsigned long pgshift;
2884 
2885 		if (unmap.argsz < (minsz + sizeof(bitmap)))
2886 			return -EINVAL;
2887 
2888 		if (copy_from_user(&bitmap,
2889 				   (void __user *)(arg + minsz),
2890 				   sizeof(bitmap)))
2891 			return -EFAULT;
2892 
2893 		if (!access_ok((void __user *)bitmap.data, bitmap.size))
2894 			return -EINVAL;
2895 
2896 		pgshift = __ffs(bitmap.pgsize);
2897 		ret = verify_bitmap_size(unmap.size >> pgshift,
2898 					 bitmap.size);
2899 		if (ret)
2900 			return ret;
2901 	}
2902 
2903 	ret = vfio_dma_do_unmap(iommu, &unmap, &bitmap);
2904 	if (ret)
2905 		return ret;
2906 
2907 	return copy_to_user((void __user *)arg, &unmap, minsz) ?
2908 			-EFAULT : 0;
2909 }
2910 
2911 static int vfio_iommu_type1_dirty_pages(struct vfio_iommu *iommu,
2912 					unsigned long arg)
2913 {
2914 	struct vfio_iommu_type1_dirty_bitmap dirty;
2915 	uint32_t mask = VFIO_IOMMU_DIRTY_PAGES_FLAG_START |
2916 			VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP |
2917 			VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP;
2918 	unsigned long minsz;
2919 	int ret = 0;
2920 
2921 	if (!iommu->v2)
2922 		return -EACCES;
2923 
2924 	minsz = offsetofend(struct vfio_iommu_type1_dirty_bitmap, flags);
2925 
2926 	if (copy_from_user(&dirty, (void __user *)arg, minsz))
2927 		return -EFAULT;
2928 
2929 	if (dirty.argsz < minsz || dirty.flags & ~mask)
2930 		return -EINVAL;
2931 
2932 	/* only one flag should be set at a time */
2933 	if (__ffs(dirty.flags) != __fls(dirty.flags))
2934 		return -EINVAL;
2935 
2936 	if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_START) {
2937 		size_t pgsize;
2938 
2939 		mutex_lock(&iommu->lock);
2940 		pgsize = 1 << __ffs(iommu->pgsize_bitmap);
2941 		if (!iommu->dirty_page_tracking) {
2942 			ret = vfio_dma_bitmap_alloc_all(iommu, pgsize);
2943 			if (!ret)
2944 				iommu->dirty_page_tracking = true;
2945 		}
2946 		mutex_unlock(&iommu->lock);
2947 		return ret;
2948 	} else if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_STOP) {
2949 		mutex_lock(&iommu->lock);
2950 		if (iommu->dirty_page_tracking) {
2951 			iommu->dirty_page_tracking = false;
2952 			vfio_dma_bitmap_free_all(iommu);
2953 		}
2954 		mutex_unlock(&iommu->lock);
2955 		return 0;
2956 	} else if (dirty.flags & VFIO_IOMMU_DIRTY_PAGES_FLAG_GET_BITMAP) {
2957 		struct vfio_iommu_type1_dirty_bitmap_get range;
2958 		unsigned long pgshift;
2959 		size_t data_size = dirty.argsz - minsz;
2960 		size_t iommu_pgsize;
2961 
2962 		if (!data_size || data_size < sizeof(range))
2963 			return -EINVAL;
2964 
2965 		if (copy_from_user(&range, (void __user *)(arg + minsz),
2966 				   sizeof(range)))
2967 			return -EFAULT;
2968 
2969 		if (range.iova + range.size < range.iova)
2970 			return -EINVAL;
2971 		if (!access_ok((void __user *)range.bitmap.data,
2972 			       range.bitmap.size))
2973 			return -EINVAL;
2974 
2975 		pgshift = __ffs(range.bitmap.pgsize);
2976 		ret = verify_bitmap_size(range.size >> pgshift,
2977 					 range.bitmap.size);
2978 		if (ret)
2979 			return ret;
2980 
2981 		mutex_lock(&iommu->lock);
2982 
2983 		iommu_pgsize = (size_t)1 << __ffs(iommu->pgsize_bitmap);
2984 
2985 		/* allow only smallest supported pgsize */
2986 		if (range.bitmap.pgsize != iommu_pgsize) {
2987 			ret = -EINVAL;
2988 			goto out_unlock;
2989 		}
2990 		if (range.iova & (iommu_pgsize - 1)) {
2991 			ret = -EINVAL;
2992 			goto out_unlock;
2993 		}
2994 		if (!range.size || range.size & (iommu_pgsize - 1)) {
2995 			ret = -EINVAL;
2996 			goto out_unlock;
2997 		}
2998 
2999 		if (iommu->dirty_page_tracking)
3000 			ret = vfio_iova_dirty_bitmap(range.bitmap.data,
3001 						     iommu, range.iova,
3002 						     range.size,
3003 						     range.bitmap.pgsize);
3004 		else
3005 			ret = -EINVAL;
3006 out_unlock:
3007 		mutex_unlock(&iommu->lock);
3008 
3009 		return ret;
3010 	}
3011 
3012 	return -EINVAL;
3013 }
3014 
3015 static long vfio_iommu_type1_ioctl(void *iommu_data,
3016 				   unsigned int cmd, unsigned long arg)
3017 {
3018 	struct vfio_iommu *iommu = iommu_data;
3019 
3020 	switch (cmd) {
3021 	case VFIO_CHECK_EXTENSION:
3022 		return vfio_iommu_type1_check_extension(iommu, arg);
3023 	case VFIO_IOMMU_GET_INFO:
3024 		return vfio_iommu_type1_get_info(iommu, arg);
3025 	case VFIO_IOMMU_MAP_DMA:
3026 		return vfio_iommu_type1_map_dma(iommu, arg);
3027 	case VFIO_IOMMU_UNMAP_DMA:
3028 		return vfio_iommu_type1_unmap_dma(iommu, arg);
3029 	case VFIO_IOMMU_DIRTY_PAGES:
3030 		return vfio_iommu_type1_dirty_pages(iommu, arg);
3031 	default:
3032 		return -ENOTTY;
3033 	}
3034 }
3035 
3036 static void vfio_iommu_type1_register_device(void *iommu_data,
3037 					     struct vfio_device *vdev)
3038 {
3039 	struct vfio_iommu *iommu = iommu_data;
3040 
3041 	if (!vdev->ops->dma_unmap)
3042 		return;
3043 
3044 	/*
3045 	 * list_empty(&iommu->device_list) is tested under the iommu->lock while
3046 	 * iteration for dma_unmap must be done under the device_list_lock.
3047 	 * Holding both locks here allows avoiding the device_list_lock in
3048 	 * several fast paths. See vfio_notify_dma_unmap()
3049 	 */
3050 	mutex_lock(&iommu->lock);
3051 	mutex_lock(&iommu->device_list_lock);
3052 	list_add(&vdev->iommu_entry, &iommu->device_list);
3053 	mutex_unlock(&iommu->device_list_lock);
3054 	mutex_unlock(&iommu->lock);
3055 }
3056 
3057 static void vfio_iommu_type1_unregister_device(void *iommu_data,
3058 					       struct vfio_device *vdev)
3059 {
3060 	struct vfio_iommu *iommu = iommu_data;
3061 
3062 	if (!vdev->ops->dma_unmap)
3063 		return;
3064 
3065 	mutex_lock(&iommu->lock);
3066 	mutex_lock(&iommu->device_list_lock);
3067 	list_del(&vdev->iommu_entry);
3068 	mutex_unlock(&iommu->device_list_lock);
3069 	mutex_unlock(&iommu->lock);
3070 }
3071 
3072 static int vfio_iommu_type1_dma_rw_chunk(struct vfio_iommu *iommu,
3073 					 dma_addr_t user_iova, void *data,
3074 					 size_t count, bool write,
3075 					 size_t *copied)
3076 {
3077 	struct mm_struct *mm;
3078 	unsigned long vaddr;
3079 	struct vfio_dma *dma;
3080 	bool kthread = current->mm == NULL;
3081 	size_t offset;
3082 	int ret;
3083 
3084 	*copied = 0;
3085 
3086 	ret = vfio_find_dma_valid(iommu, user_iova, 1, &dma);
3087 	if (ret < 0)
3088 		return ret;
3089 
3090 	if ((write && !(dma->prot & IOMMU_WRITE)) ||
3091 			!(dma->prot & IOMMU_READ))
3092 		return -EPERM;
3093 
3094 	mm = get_task_mm(dma->task);
3095 
3096 	if (!mm)
3097 		return -EPERM;
3098 
3099 	if (kthread)
3100 		kthread_use_mm(mm);
3101 	else if (current->mm != mm)
3102 		goto out;
3103 
3104 	offset = user_iova - dma->iova;
3105 
3106 	if (count > dma->size - offset)
3107 		count = dma->size - offset;
3108 
3109 	vaddr = dma->vaddr + offset;
3110 
3111 	if (write) {
3112 		*copied = copy_to_user((void __user *)vaddr, data,
3113 					 count) ? 0 : count;
3114 		if (*copied && iommu->dirty_page_tracking) {
3115 			unsigned long pgshift = __ffs(iommu->pgsize_bitmap);
3116 			/*
3117 			 * Bitmap populated with the smallest supported page
3118 			 * size
3119 			 */
3120 			bitmap_set(dma->bitmap, offset >> pgshift,
3121 				   ((offset + *copied - 1) >> pgshift) -
3122 				   (offset >> pgshift) + 1);
3123 		}
3124 	} else
3125 		*copied = copy_from_user(data, (void __user *)vaddr,
3126 					   count) ? 0 : count;
3127 	if (kthread)
3128 		kthread_unuse_mm(mm);
3129 out:
3130 	mmput(mm);
3131 	return *copied ? 0 : -EFAULT;
3132 }
3133 
3134 static int vfio_iommu_type1_dma_rw(void *iommu_data, dma_addr_t user_iova,
3135 				   void *data, size_t count, bool write)
3136 {
3137 	struct vfio_iommu *iommu = iommu_data;
3138 	int ret = 0;
3139 	size_t done;
3140 
3141 	mutex_lock(&iommu->lock);
3142 	while (count > 0) {
3143 		ret = vfio_iommu_type1_dma_rw_chunk(iommu, user_iova, data,
3144 						    count, write, &done);
3145 		if (ret)
3146 			break;
3147 
3148 		count -= done;
3149 		data += done;
3150 		user_iova += done;
3151 	}
3152 
3153 	mutex_unlock(&iommu->lock);
3154 	return ret;
3155 }
3156 
3157 static struct iommu_domain *
3158 vfio_iommu_type1_group_iommu_domain(void *iommu_data,
3159 				    struct iommu_group *iommu_group)
3160 {
3161 	struct iommu_domain *domain = ERR_PTR(-ENODEV);
3162 	struct vfio_iommu *iommu = iommu_data;
3163 	struct vfio_domain *d;
3164 
3165 	if (!iommu || !iommu_group)
3166 		return ERR_PTR(-EINVAL);
3167 
3168 	mutex_lock(&iommu->lock);
3169 	list_for_each_entry(d, &iommu->domain_list, next) {
3170 		if (find_iommu_group(d, iommu_group)) {
3171 			domain = d->domain;
3172 			break;
3173 		}
3174 	}
3175 	mutex_unlock(&iommu->lock);
3176 
3177 	return domain;
3178 }
3179 
3180 static void vfio_iommu_type1_notify(void *iommu_data,
3181 				    enum vfio_iommu_notify_type event)
3182 {
3183 	struct vfio_iommu *iommu = iommu_data;
3184 
3185 	if (event != VFIO_IOMMU_CONTAINER_CLOSE)
3186 		return;
3187 	mutex_lock(&iommu->lock);
3188 	iommu->container_open = false;
3189 	mutex_unlock(&iommu->lock);
3190 	wake_up_all(&iommu->vaddr_wait);
3191 }
3192 
3193 static const struct vfio_iommu_driver_ops vfio_iommu_driver_ops_type1 = {
3194 	.name			= "vfio-iommu-type1",
3195 	.owner			= THIS_MODULE,
3196 	.open			= vfio_iommu_type1_open,
3197 	.release		= vfio_iommu_type1_release,
3198 	.ioctl			= vfio_iommu_type1_ioctl,
3199 	.attach_group		= vfio_iommu_type1_attach_group,
3200 	.detach_group		= vfio_iommu_type1_detach_group,
3201 	.pin_pages		= vfio_iommu_type1_pin_pages,
3202 	.unpin_pages		= vfio_iommu_type1_unpin_pages,
3203 	.register_device	= vfio_iommu_type1_register_device,
3204 	.unregister_device	= vfio_iommu_type1_unregister_device,
3205 	.dma_rw			= vfio_iommu_type1_dma_rw,
3206 	.group_iommu_domain	= vfio_iommu_type1_group_iommu_domain,
3207 	.notify			= vfio_iommu_type1_notify,
3208 };
3209 
3210 static int __init vfio_iommu_type1_init(void)
3211 {
3212 	return vfio_register_iommu_driver(&vfio_iommu_driver_ops_type1);
3213 }
3214 
3215 static void __exit vfio_iommu_type1_cleanup(void)
3216 {
3217 	vfio_unregister_iommu_driver(&vfio_iommu_driver_ops_type1);
3218 }
3219 
3220 module_init(vfio_iommu_type1_init);
3221 module_exit(vfio_iommu_type1_cleanup);
3222 
3223 MODULE_VERSION(DRIVER_VERSION);
3224 MODULE_LICENSE("GPL v2");
3225 MODULE_AUTHOR(DRIVER_AUTHOR);
3226 MODULE_DESCRIPTION(DRIVER_DESC);
3227