summaryrefslogtreecommitdiff
path: root/arch/arm/kvm/mmu.c
blob: 41fa75df107fba964975bf24cc965ae2445c6324 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
/*
 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License, version 2, as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
 */

#include <linux/mman.h>
#include <linux/kvm_host.h>
#include <linux/io.h>
#include <trace/events/kvm.h>
#include <asm/idmap.h>
#include <asm/pgalloc.h>
#include <asm/cacheflush.h>
#include <asm/kvm_arm.h>
#include <asm/kvm_mmu.h>
#include <asm/kvm_mmio.h>
#include <asm/kvm_asm.h>
#include <asm/kvm_emulate.h>
#include <asm/mach/map.h>
#include <trace/events/kvm.h>

#include "trace.h"

extern char  __hyp_idmap_text_start[], __hyp_idmap_text_end[];

static DEFINE_MUTEX(kvm_hyp_pgd_mutex);

static void kvm_tlb_flush_vmid(struct kvm *kvm)
{
	kvm_call_hyp(__kvm_tlb_flush_vmid, kvm);
}

static void kvm_set_pte(pte_t *pte, pte_t new_pte)
{
	pte_val(*pte) = new_pte;
	/*
	 * flush_pmd_entry just takes a void pointer and cleans the necessary
	 * cache entries, so we can reuse the function for ptes.
	 */
	flush_pmd_entry(pte);
}

static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
				  int min, int max)
{
	void *page;

	BUG_ON(max > KVM_NR_MEM_OBJS);
	if (cache->nobjs >= min)
		return 0;
	while (cache->nobjs < max) {
		page = (void *)__get_free_page(PGALLOC_GFP);
		if (!page)
			return -ENOMEM;
		cache->objects[cache->nobjs++] = page;
	}
	return 0;
}

static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
{
	while (mc->nobjs)
		free_page((unsigned long)mc->objects[--mc->nobjs]);
}

static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
{
	void *p;

	BUG_ON(!mc || !mc->nobjs);
	p = mc->objects[--mc->nobjs];
	return p;
}

static void free_ptes(pmd_t *pmd, unsigned long addr)
{
	pte_t *pte;
	unsigned int i;

	for (i = 0; i < PTRS_PER_PMD; i++, addr += PMD_SIZE) {
		if (!pmd_none(*pmd) && pmd_table(*pmd)) {
			pte = pte_offset_kernel(pmd, addr);
			pte_free_kernel(NULL, pte);
		}
		pmd++;
	}
}

/**
 * free_hyp_pmds - free a Hyp-mode level-2 tables and child level-3 tables
 *
 * Assumes this is a page table used strictly in Hyp-mode and therefore contains
 * only mappings in the kernel memory area, which is above PAGE_OFFSET.
 */
void free_hyp_pmds(void)
{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	unsigned long addr;

	mutex_lock(&kvm_hyp_pgd_mutex);
	for (addr = PAGE_OFFSET; addr != 0; addr += PGDIR_SIZE) {
		pgd = hyp_pgd + pgd_index(addr);
		pud = pud_offset(pgd, addr);

		if (pud_none(*pud))
			continue;
		BUG_ON(pud_bad(*pud));

		pmd = pmd_offset(pud, addr);
		free_ptes(pmd, addr);
		pmd_free(NULL, pmd);
		pud_clear(pud);
	}
	mutex_unlock(&kvm_hyp_pgd_mutex);
}

static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start,
				    unsigned long end)
{
	pte_t *pte;
	unsigned long addr;
	struct page *page;

	for (addr = start & PAGE_MASK; addr < end; addr += PAGE_SIZE) {
		pte = pte_offset_kernel(pmd, addr);
		BUG_ON(!virt_addr_valid(addr));
		page = virt_to_page(addr);
		kvm_set_pte(pte, mk_pte(page, PAGE_HYP));
	}
}

static void create_hyp_io_pte_mappings(pmd_t *pmd, unsigned long start,
				       unsigned long end,
				       unsigned long *pfn_base)
{
	pte_t *pte;
	unsigned long addr;

	for (addr = start & PAGE_MASK; addr < end; addr += PAGE_SIZE) {
		pte = pte_offset_kernel(pmd, addr);
		BUG_ON(pfn_valid(*pfn_base));
		kvm_set_pte(pte, pfn_pte(*pfn_base, PAGE_HYP_DEVICE));
		(*pfn_base)++;
	}
}

static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start,
				   unsigned long end, unsigned long *pfn_base)
{
	pmd_t *pmd;
	pte_t *pte;
	unsigned long addr, next;

	for (addr = start; addr < end; addr = next) {
		pmd = pmd_offset(pud, addr);

		BUG_ON(pmd_sect(*pmd));

		if (pmd_none(*pmd)) {
			pte = pte_alloc_one_kernel(NULL, addr);
			if (!pte) {
				kvm_err("Cannot allocate Hyp pte\n");
				return -ENOMEM;
			}
			pmd_populate_kernel(NULL, pmd, pte);
		}

		next = pmd_addr_end(addr, end);

		/*
		 * If pfn_base is NULL, we map kernel pages into HYP with the
		 * virtual address. Otherwise, this is considered an I/O
		 * mapping and we map the physical region starting at
		 * *pfn_base to [start, end[.
		 */
		if (!pfn_base)
			create_hyp_pte_mappings(pmd, addr, next);
		else
			create_hyp_io_pte_mappings(pmd, addr, next, pfn_base);
	}

	return 0;
}

static int __create_hyp_mappings(void *from, void *to, unsigned long *pfn_base)
{
	unsigned long start = (unsigned long)from;
	unsigned long end = (unsigned long)to;
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	unsigned long addr, next;
	int err = 0;

	BUG_ON(start > end);
	if (start < PAGE_OFFSET)
		return -EINVAL;

	mutex_lock(&kvm_hyp_pgd_mutex);
	for (addr = start; addr < end; addr = next) {
		pgd = hyp_pgd + pgd_index(addr);
		pud = pud_offset(pgd, addr);

		if (pud_none_or_clear_bad(pud)) {
			pmd = pmd_alloc_one(NULL, addr);
			if (!pmd) {
				kvm_err("Cannot allocate Hyp pmd\n");
				err = -ENOMEM;
				goto out;
			}
			pud_populate(NULL, pud, pmd);
		}

		next = pgd_addr_end(addr, end);
		err = create_hyp_pmd_mappings(pud, addr, next, pfn_base);
		if (err)
			goto out;
	}
out:
	mutex_unlock(&kvm_hyp_pgd_mutex);
	return err;
}

/**
 * create_hyp_mappings - map a kernel virtual address range in Hyp mode
 * @from:	The virtual kernel start address of the range
 * @to:		The virtual kernel end address of the range (exclusive)
 *
 * The same virtual address as the kernel virtual address is also used in
 * Hyp-mode mapping to the same underlying physical pages.
 *
 * Note: Wrapping around zero in the "to" address is not supported.
 */
int create_hyp_mappings(void *from, void *to)
{
	return __create_hyp_mappings(from, to, NULL);
}

/**
 * create_hyp_io_mappings - map a physical IO range in Hyp mode
 * @from:	The virtual HYP start address of the range
 * @to:		The virtual HYP end address of the range (exclusive)
 * @addr:	The physical start address which gets mapped
 */
int create_hyp_io_mappings(void *from, void *to, phys_addr_t addr)
{
	unsigned long pfn = __phys_to_pfn(addr);
	return __create_hyp_mappings(from, to, &pfn);
}

/**
 * kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation.
 * @kvm:	The KVM struct pointer for the VM.
 *
 * Allocates the 1st level table only of size defined by S2_PGD_ORDER (can
 * support either full 40-bit input addresses or limited to 32-bit input
 * addresses). Clears the allocated pages.
 *
 * Note we don't need locking here as this is only called when the VM is
 * created, which can only be done once.
 */
int kvm_alloc_stage2_pgd(struct kvm *kvm)
{
	pgd_t *pgd;

	if (kvm->arch.pgd != NULL) {
		kvm_err("kvm_arch already initialized?\n");
		return -EINVAL;
	}

	pgd = (pgd_t *)__get_free_pages(GFP_KERNEL, S2_PGD_ORDER);
	if (!pgd)
		return -ENOMEM;

	/* stage-2 pgd must be aligned to its size */
	VM_BUG_ON((unsigned long)pgd & (S2_PGD_SIZE - 1));

	memset(pgd, 0, PTRS_PER_S2_PGD * sizeof(pgd_t));
	clean_dcache_area(pgd, PTRS_PER_S2_PGD * sizeof(pgd_t));
	kvm->arch.pgd = pgd;

	return 0;
}

static void clear_pud_entry(pud_t *pud)
{
	pmd_t *pmd_table = pmd_offset(pud, 0);
	pud_clear(pud);
	pmd_free(NULL, pmd_table);
	put_page(virt_to_page(pud));
}

static void clear_pmd_entry(pmd_t *pmd)
{
	pte_t *pte_table = pte_offset_kernel(pmd, 0);
	pmd_clear(pmd);
	pte_free_kernel(NULL, pte_table);
	put_page(virt_to_page(pmd));
}

static bool pmd_empty(pmd_t *pmd)
{
	struct page *pmd_page = virt_to_page(pmd);
	return page_count(pmd_page) == 1;
}

static void clear_pte_entry(pte_t *pte)
{
	if (pte_present(*pte)) {
		kvm_set_pte(pte, __pte(0));
		put_page(virt_to_page(pte));
	}
}

static bool pte_empty(pte_t *pte)
{
	struct page *pte_page = virt_to_page(pte);
	return page_count(pte_page) == 1;
}

/**
 * unmap_stage2_range -- Clear stage2 page table entries to unmap a range
 * @kvm:   The VM pointer
 * @start: The intermediate physical base address of the range to unmap
 * @size:  The size of the area to unmap
 *
 * Clear a range of stage-2 mappings, lowering the various ref-counts.  Must
 * be called while holding mmu_lock (unless for freeing the stage2 pgd before
 * destroying the VM), otherwise another faulting VCPU may come in and mess
 * with things behind our backs.
 */
static void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size)
{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte;
	phys_addr_t addr = start, end = start + size;
	u64 range;

	while (addr < end) {
		pgd = kvm->arch.pgd + pgd_index(addr);
		pud = pud_offset(pgd, addr);
		if (pud_none(*pud)) {
			addr += PUD_SIZE;
			continue;
		}

		pmd = pmd_offset(pud, addr);
		if (pmd_none(*pmd)) {
			addr += PMD_SIZE;
			continue;
		}

		pte = pte_offset_kernel(pmd, addr);
		clear_pte_entry(pte);
		range = PAGE_SIZE;

		/* If we emptied the pte, walk back up the ladder */
		if (pte_empty(pte)) {
			clear_pmd_entry(pmd);
			range = PMD_SIZE;
			if (pmd_empty(pmd)) {
				clear_pud_entry(pud);
				range = PUD_SIZE;
			}
		}

		addr += range;
	}
}

/**
 * kvm_free_stage2_pgd - free all stage-2 tables
 * @kvm:	The KVM struct pointer for the VM.
 *
 * Walks the level-1 page table pointed to by kvm->arch.pgd and frees all
 * underlying level-2 and level-3 tables before freeing the actual level-1 table
 * and setting the struct pointer to NULL.
 *
 * Note we don't need locking here as this is only called when the VM is
 * destroyed, which can only be done once.
 */
void kvm_free_stage2_pgd(struct kvm *kvm)
{
	if (kvm->arch.pgd == NULL)
		return;

	unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE);
	free_pages((unsigned long)kvm->arch.pgd, S2_PGD_ORDER);
	kvm->arch.pgd = NULL;
}


static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
			  phys_addr_t addr, const pte_t *new_pte, bool iomap)
{
	pgd_t *pgd;
	pud_t *pud;
	pmd_t *pmd;
	pte_t *pte, old_pte;

	/* Create 2nd stage page table mapping - Level 1 */
	pgd = kvm->arch.pgd + pgd_index(addr);
	pud = pud_offset(pgd, addr);
	if (pud_none(*pud)) {
		if (!cache)
			return 0; /* ignore calls from kvm_set_spte_hva */
		pmd = mmu_memory_cache_alloc(cache);
		pud_populate(NULL, pud, pmd);
		pmd += pmd_index(addr);
		get_page(virt_to_page(pud));
	} else
		pmd = pmd_offset(pud, addr);

	/* Create 2nd stage page table mapping - Level 2 */
	if (pmd_none(*pmd)) {
		if (!cache)
			return 0; /* ignore calls from kvm_set_spte_hva */
		pte = mmu_memory_cache_alloc(cache);
		clean_pte_table(pte);
		pmd_populate_kernel(NULL, pmd, pte);
		pte += pte_index(addr);
		get_page(virt_to_page(pmd));
	} else
		pte = pte_offset_kernel(pmd, addr);

	if (iomap && pte_present(*pte))
		return -EFAULT;

	/* Create 2nd stage page table mapping - Level 3 */
	old_pte = *pte;
	kvm_set_pte(pte, *new_pte);
	if (pte_present(old_pte))
		kvm_tlb_flush_vmid(kvm);
	else
		get_page(virt_to_page(pte));

	return 0;
}

/**
 * kvm_phys_addr_ioremap - map a device range to guest IPA
 *
 * @kvm:	The KVM pointer
 * @guest_ipa:	The IPA at which to insert the mapping
 * @pa:		The physical address of the device
 * @size:	The size of the mapping
 */
int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
			  phys_addr_t pa, unsigned long size)
{
	phys_addr_t addr, end;
	int ret = 0;
	unsigned long pfn;
	struct kvm_mmu_memory_cache cache = { 0, };

	end = (guest_ipa + size + PAGE_SIZE - 1) & PAGE_MASK;
	pfn = __phys_to_pfn(pa);

	for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) {
		pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE | L_PTE_S2_RDWR);

		ret = mmu_topup_memory_cache(&cache, 2, 2);
		if (ret)
			goto out;
		spin_lock(&kvm->mmu_lock);
		ret = stage2_set_pte(kvm, &cache, addr, &pte, true);
		spin_unlock(&kvm->mmu_lock);
		if (ret)
			goto out;

		pfn++;
	}

out:
	mmu_free_memory_cache(&cache);
	return ret;
}

static void coherent_icache_guest_page(struct kvm *kvm, gfn_t gfn)
{
	/*
	 * If we are going to insert an instruction page and the icache is
	 * either VIPT or PIPT, there is a potential problem where the host
	 * (or another VM) may have used the same page as this guest, and we
	 * read incorrect data from the icache.  If we're using a PIPT cache,
	 * we can invalidate just that page, but if we are using a VIPT cache
	 * we need to invalidate the entire icache - damn shame - as written
	 * in the ARM ARM (DDI 0406C.b - Page B3-1393).
	 *
	 * VIVT caches are tagged using both the ASID and the VMID and doesn't
	 * need any kind of flushing (DDI 0406C.b - Page B3-1392).
	 */
	if (icache_is_pipt()) {
		unsigned long hva = gfn_to_hva(kvm, gfn);
		__cpuc_coherent_user_range(hva, hva + PAGE_SIZE);
	} else if (!icache_is_vivt_asid_tagged()) {
		/* any kind of VIPT cache */
		__flush_icache_all();
	}
}

static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
			  gfn_t gfn, struct kvm_memory_slot *memslot,
			  unsigned long fault_status)
{
	pte_t new_pte;
	pfn_t pfn;
	int ret;
	bool write_fault, writable;
	unsigned long mmu_seq;
	struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;

	write_fault = kvm_is_write_fault(kvm_vcpu_get_hsr(vcpu));
	if (fault_status == FSC_PERM && !write_fault) {
		kvm_err("Unexpected L2 read permission error\n");
		return -EFAULT;
	}

	/* We need minimum second+third level pages */
	ret = mmu_topup_memory_cache(memcache, 2, KVM_NR_MEM_OBJS);
	if (ret)
		return ret;

	mmu_seq = vcpu->kvm->mmu_notifier_seq;
	/*
	 * Ensure the read of mmu_notifier_seq happens before we call
	 * gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk
	 * the page we just got a reference to gets unmapped before we have a
	 * chance to grab the mmu_lock, which ensure that if the page gets
	 * unmapped afterwards, the call to kvm_unmap_hva will take it away
	 * from us again properly. This smp_rmb() interacts with the smp_wmb()
	 * in kvm_mmu_notifier_invalidate_<page|range_end>.
	 */
	smp_rmb();

	pfn = gfn_to_pfn_prot(vcpu->kvm, gfn, write_fault, &writable);
	if (is_error_pfn(pfn))
		return -EFAULT;

	new_pte = pfn_pte(pfn, PAGE_S2);
	coherent_icache_guest_page(vcpu->kvm, gfn);

	spin_lock(&vcpu->kvm->mmu_lock);
	if (mmu_notifier_retry(vcpu->kvm, mmu_seq))
		goto out_unlock;
	if (writable) {
		pte_val(new_pte) |= L_PTE_S2_RDWR;
		kvm_set_pfn_dirty(pfn);
	}
	stage2_set_pte(vcpu->kvm, memcache, fault_ipa, &new_pte, false);

out_unlock:
	spin_unlock(&vcpu->kvm->mmu_lock);
	kvm_release_pfn_clean(pfn);
	return 0;
}

/**
 * kvm_handle_guest_abort - handles all 2nd stage aborts
 * @vcpu:	the VCPU pointer
 * @run:	the kvm_run structure
 *
 * Any abort that gets to the host is almost guaranteed to be caused by a
 * missing second stage translation table entry, which can mean that either the
 * guest simply needs more memory and we must allocate an appropriate page or it
 * can mean that the guest tried to access I/O memory, which is emulated by user
 * space. The distinction is based on the IPA causing the fault and whether this
 * memory region has been registered as standard RAM by user space.
 */
int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
{
	unsigned long hsr_ec;
	unsigned long fault_status;
	phys_addr_t fault_ipa;
	struct kvm_memory_slot *memslot;
	bool is_iabt;
	gfn_t gfn;
	int ret, idx;

	hsr_ec = kvm_vcpu_trap_get_class(vcpu);
	is_iabt = (hsr_ec == HSR_EC_IABT);
	fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);

	trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_hsr(vcpu),
			      kvm_vcpu_get_hfar(vcpu), fault_ipa);

	/* Check the stage-2 fault is trans. fault or write fault */
	fault_status = (kvm_vcpu_get_hsr(vcpu) & HSR_FSC_TYPE);
	if (fault_status != FSC_FAULT && fault_status != FSC_PERM) {
		kvm_err("Unsupported fault status: EC=%#lx DFCS=%#lx\n",
			hsr_ec, fault_status);
		return -EFAULT;
	}

	idx = srcu_read_lock(&vcpu->kvm->srcu);

	gfn = fault_ipa >> PAGE_SHIFT;
	if (!kvm_is_visible_gfn(vcpu->kvm, gfn)) {
		if (is_iabt) {
			/* Prefetch Abort on I/O address */
			kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu));
			ret = 1;
			goto out_unlock;
		}

		if (fault_status != FSC_FAULT) {
			kvm_err("Unsupported fault status on io memory: %#lx\n",
				fault_status);
			ret = -EFAULT;
			goto out_unlock;
		}

		/* Adjust page offset */
		fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ~PAGE_MASK;
		ret = io_mem_abort(vcpu, run, fault_ipa);
		goto out_unlock;
	}

	memslot = gfn_to_memslot(vcpu->kvm, gfn);

	ret = user_mem_abort(vcpu, fault_ipa, gfn, memslot, fault_status);
	if (ret == 0)
		ret = 1;
out_unlock:
	srcu_read_unlock(&vcpu->kvm->srcu, idx);
	return ret;
}

static void handle_hva_to_gpa(struct kvm *kvm,
			      unsigned long start,
			      unsigned long end,
			      void (*handler)(struct kvm *kvm,
					      gpa_t gpa, void *data),
			      void *data)
{
	struct kvm_memslots *slots;
	struct kvm_memory_slot *memslot;

	slots = kvm_memslots(kvm);

	/* we only care about the pages that the guest sees */
	kvm_for_each_memslot(memslot, slots) {
		unsigned long hva_start, hva_end;
		gfn_t gfn, gfn_end;

		hva_start = max(start, memslot->userspace_addr);
		hva_end = min(end, memslot->userspace_addr +
					(memslot->npages << PAGE_SHIFT));
		if (hva_start >= hva_end)
			continue;

		/*
		 * {gfn(page) | page intersects with [hva_start, hva_end)} =
		 * {gfn_start, gfn_start+1, ..., gfn_end-1}.
		 */
		gfn = hva_to_gfn_memslot(hva_start, memslot);
		gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);

		for (; gfn < gfn_end; ++gfn) {
			gpa_t gpa = gfn << PAGE_SHIFT;
			handler(kvm, gpa, data);
		}
	}
}

static void kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, void *data)
{
	unmap_stage2_range(kvm, gpa, PAGE_SIZE);
	kvm_tlb_flush_vmid(kvm);
}

int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
{
	unsigned long end = hva + PAGE_SIZE;

	if (!kvm->arch.pgd)
		return 0;

	trace_kvm_unmap_hva(hva);
	handle_hva_to_gpa(kvm, hva, end, &kvm_unmap_hva_handler, NULL);
	return 0;
}

int kvm_unmap_hva_range(struct kvm *kvm,
			unsigned long start, unsigned long end)
{
	if (!kvm->arch.pgd)
		return 0;

	trace_kvm_unmap_hva_range(start, end);
	handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, NULL);
	return 0;
}

static void kvm_set_spte_handler(struct kvm *kvm, gpa_t gpa, void *data)
{
	pte_t *pte = (pte_t *)data;

	stage2_set_pte(kvm, NULL, gpa, pte, false);
}


void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
{
	unsigned long end = hva + PAGE_SIZE;
	pte_t stage2_pte;

	if (!kvm->arch.pgd)
		return;

	trace_kvm_set_spte_hva(hva);
	stage2_pte = pfn_pte(pte_pfn(pte), PAGE_S2);
	handle_hva_to_gpa(kvm, hva, end, &kvm_set_spte_handler, &stage2_pte);
}

void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu)
{
	mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
}

phys_addr_t kvm_mmu_get_httbr(void)
{
	VM_BUG_ON(!virt_addr_valid(hyp_pgd));
	return virt_to_phys(hyp_pgd);
}

int kvm_mmu_init(void)
{
	if (!hyp_pgd) {
		kvm_err("Hyp mode PGD not allocated\n");
		return -ENOMEM;
	}

	return 0;
}

/**
 * kvm_clear_idmap - remove all idmaps from the hyp pgd
 *
 * Free the underlying pmds for all pgds in range and clear the pgds (but
 * don't free them) afterwards.
 */
void kvm_clear_hyp_idmap(void)
{
	unsigned long addr, end;
	unsigned long next;
	pgd_t *pgd = hyp_pgd;
	pud_t *pud;
	pmd_t *pmd;

	addr = virt_to_phys(__hyp_idmap_text_start);
	end = virt_to_phys(__hyp_idmap_text_end);

	pgd += pgd_index(addr);
	do {
		next = pgd_addr_end(addr, end);
		if (pgd_none_or_clear_bad(pgd))
			continue;
		pud = pud_offset(pgd, addr);
		pmd = pmd_offset(pud, addr);

		pud_clear(pud);
		clean_pmd_entry(pmd);
		pmd_free(NULL, (pmd_t *)((unsigned long)pmd & PAGE_MASK));
	} while (pgd++, addr = next, addr < end);
}