Merge branch 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...
[platform/kernel/linux-exynos.git] / virt / kvm / arm / mmu.c
1 /*
2  * Copyright (C) 2012 - Virtual Open Systems and Columbia University
3  * Author: Christoffer Dall <c.dall@virtualopensystems.com>
4  *
5  * This program is free software; you can redistribute it and/or modify
6  * it under the terms of the GNU General Public License, version 2, as
7  * published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12  * GNU General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, write to the Free Software
16  * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
17  */
18
19 #include <linux/mman.h>
20 #include <linux/kvm_host.h>
21 #include <linux/io.h>
22 #include <linux/hugetlb.h>
23 #include <linux/sched/signal.h>
24 #include <trace/events/kvm.h>
25 #include <asm/pgalloc.h>
26 #include <asm/cacheflush.h>
27 #include <asm/kvm_arm.h>
28 #include <asm/kvm_mmu.h>
29 #include <asm/kvm_mmio.h>
30 #include <asm/kvm_asm.h>
31 #include <asm/kvm_emulate.h>
32 #include <asm/virt.h>
33 #include <asm/system_misc.h>
34
35 #include "trace.h"
36
37 static pgd_t *boot_hyp_pgd;
38 static pgd_t *hyp_pgd;
39 static pgd_t *merged_hyp_pgd;
40 static DEFINE_MUTEX(kvm_hyp_pgd_mutex);
41
42 static unsigned long hyp_idmap_start;
43 static unsigned long hyp_idmap_end;
44 static phys_addr_t hyp_idmap_vector;
45
46 #define S2_PGD_SIZE     (PTRS_PER_S2_PGD * sizeof(pgd_t))
47 #define hyp_pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t))
48
49 #define KVM_S2PTE_FLAG_IS_IOMAP         (1UL << 0)
50 #define KVM_S2_FLAG_LOGGING_ACTIVE      (1UL << 1)
51
52 static bool memslot_is_logging(struct kvm_memory_slot *memslot)
53 {
54         return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY);
55 }
56
57 /**
58  * kvm_flush_remote_tlbs() - flush all VM TLB entries for v7/8
59  * @kvm:        pointer to kvm structure.
60  *
61  * Interface to HYP function to flush all VM TLB entries
62  */
63 void kvm_flush_remote_tlbs(struct kvm *kvm)
64 {
65         kvm_call_hyp(__kvm_tlb_flush_vmid, kvm);
66 }
67
68 static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
69 {
70         kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa);
71 }
72
73 /*
74  * D-Cache management functions. They take the page table entries by
75  * value, as they are flushing the cache using the kernel mapping (or
76  * kmap on 32bit).
77  */
78 static void kvm_flush_dcache_pte(pte_t pte)
79 {
80         __kvm_flush_dcache_pte(pte);
81 }
82
83 static void kvm_flush_dcache_pmd(pmd_t pmd)
84 {
85         __kvm_flush_dcache_pmd(pmd);
86 }
87
88 static void kvm_flush_dcache_pud(pud_t pud)
89 {
90         __kvm_flush_dcache_pud(pud);
91 }
92
93 static bool kvm_is_device_pfn(unsigned long pfn)
94 {
95         return !pfn_valid(pfn);
96 }
97
98 /**
99  * stage2_dissolve_pmd() - clear and flush huge PMD entry
100  * @kvm:        pointer to kvm structure.
101  * @addr:       IPA
102  * @pmd:        pmd pointer for IPA
103  *
104  * Function clears a PMD entry, flushes addr 1st and 2nd stage TLBs. Marks all
105  * pages in the range dirty.
106  */
107 static void stage2_dissolve_pmd(struct kvm *kvm, phys_addr_t addr, pmd_t *pmd)
108 {
109         if (!pmd_thp_or_huge(*pmd))
110                 return;
111
112         pmd_clear(pmd);
113         kvm_tlb_flush_vmid_ipa(kvm, addr);
114         put_page(virt_to_page(pmd));
115 }
116
117 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
118                                   int min, int max)
119 {
120         void *page;
121
122         BUG_ON(max > KVM_NR_MEM_OBJS);
123         if (cache->nobjs >= min)
124                 return 0;
125         while (cache->nobjs < max) {
126                 page = (void *)__get_free_page(PGALLOC_GFP);
127                 if (!page)
128                         return -ENOMEM;
129                 cache->objects[cache->nobjs++] = page;
130         }
131         return 0;
132 }
133
134 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
135 {
136         while (mc->nobjs)
137                 free_page((unsigned long)mc->objects[--mc->nobjs]);
138 }
139
140 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
141 {
142         void *p;
143
144         BUG_ON(!mc || !mc->nobjs);
145         p = mc->objects[--mc->nobjs];
146         return p;
147 }
148
149 static void clear_stage2_pgd_entry(struct kvm *kvm, pgd_t *pgd, phys_addr_t addr)
150 {
151         pud_t *pud_table __maybe_unused = stage2_pud_offset(pgd, 0UL);
152         stage2_pgd_clear(pgd);
153         kvm_tlb_flush_vmid_ipa(kvm, addr);
154         stage2_pud_free(pud_table);
155         put_page(virt_to_page(pgd));
156 }
157
158 static void clear_stage2_pud_entry(struct kvm *kvm, pud_t *pud, phys_addr_t addr)
159 {
160         pmd_t *pmd_table __maybe_unused = stage2_pmd_offset(pud, 0);
161         VM_BUG_ON(stage2_pud_huge(*pud));
162         stage2_pud_clear(pud);
163         kvm_tlb_flush_vmid_ipa(kvm, addr);
164         stage2_pmd_free(pmd_table);
165         put_page(virt_to_page(pud));
166 }
167
168 static void clear_stage2_pmd_entry(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr)
169 {
170         pte_t *pte_table = pte_offset_kernel(pmd, 0);
171         VM_BUG_ON(pmd_thp_or_huge(*pmd));
172         pmd_clear(pmd);
173         kvm_tlb_flush_vmid_ipa(kvm, addr);
174         pte_free_kernel(NULL, pte_table);
175         put_page(virt_to_page(pmd));
176 }
177
178 /*
179  * Unmapping vs dcache management:
180  *
181  * If a guest maps certain memory pages as uncached, all writes will
182  * bypass the data cache and go directly to RAM.  However, the CPUs
183  * can still speculate reads (not writes) and fill cache lines with
184  * data.
185  *
186  * Those cache lines will be *clean* cache lines though, so a
187  * clean+invalidate operation is equivalent to an invalidate
188  * operation, because no cache lines are marked dirty.
189  *
190  * Those clean cache lines could be filled prior to an uncached write
191  * by the guest, and the cache coherent IO subsystem would therefore
192  * end up writing old data to disk.
193  *
194  * This is why right after unmapping a page/section and invalidating
195  * the corresponding TLBs, we call kvm_flush_dcache_p*() to make sure
196  * the IO subsystem will never hit in the cache.
197  */
198 static void unmap_stage2_ptes(struct kvm *kvm, pmd_t *pmd,
199                        phys_addr_t addr, phys_addr_t end)
200 {
201         phys_addr_t start_addr = addr;
202         pte_t *pte, *start_pte;
203
204         start_pte = pte = pte_offset_kernel(pmd, addr);
205         do {
206                 if (!pte_none(*pte)) {
207                         pte_t old_pte = *pte;
208
209                         kvm_set_pte(pte, __pte(0));
210                         kvm_tlb_flush_vmid_ipa(kvm, addr);
211
212                         /* No need to invalidate the cache for device mappings */
213                         if (!kvm_is_device_pfn(pte_pfn(old_pte)))
214                                 kvm_flush_dcache_pte(old_pte);
215
216                         put_page(virt_to_page(pte));
217                 }
218         } while (pte++, addr += PAGE_SIZE, addr != end);
219
220         if (stage2_pte_table_empty(start_pte))
221                 clear_stage2_pmd_entry(kvm, pmd, start_addr);
222 }
223
224 static void unmap_stage2_pmds(struct kvm *kvm, pud_t *pud,
225                        phys_addr_t addr, phys_addr_t end)
226 {
227         phys_addr_t next, start_addr = addr;
228         pmd_t *pmd, *start_pmd;
229
230         start_pmd = pmd = stage2_pmd_offset(pud, addr);
231         do {
232                 next = stage2_pmd_addr_end(addr, end);
233                 if (!pmd_none(*pmd)) {
234                         if (pmd_thp_or_huge(*pmd)) {
235                                 pmd_t old_pmd = *pmd;
236
237                                 pmd_clear(pmd);
238                                 kvm_tlb_flush_vmid_ipa(kvm, addr);
239
240                                 kvm_flush_dcache_pmd(old_pmd);
241
242                                 put_page(virt_to_page(pmd));
243                         } else {
244                                 unmap_stage2_ptes(kvm, pmd, addr, next);
245                         }
246                 }
247         } while (pmd++, addr = next, addr != end);
248
249         if (stage2_pmd_table_empty(start_pmd))
250                 clear_stage2_pud_entry(kvm, pud, start_addr);
251 }
252
253 static void unmap_stage2_puds(struct kvm *kvm, pgd_t *pgd,
254                        phys_addr_t addr, phys_addr_t end)
255 {
256         phys_addr_t next, start_addr = addr;
257         pud_t *pud, *start_pud;
258
259         start_pud = pud = stage2_pud_offset(pgd, addr);
260         do {
261                 next = stage2_pud_addr_end(addr, end);
262                 if (!stage2_pud_none(*pud)) {
263                         if (stage2_pud_huge(*pud)) {
264                                 pud_t old_pud = *pud;
265
266                                 stage2_pud_clear(pud);
267                                 kvm_tlb_flush_vmid_ipa(kvm, addr);
268                                 kvm_flush_dcache_pud(old_pud);
269                                 put_page(virt_to_page(pud));
270                         } else {
271                                 unmap_stage2_pmds(kvm, pud, addr, next);
272                         }
273                 }
274         } while (pud++, addr = next, addr != end);
275
276         if (stage2_pud_table_empty(start_pud))
277                 clear_stage2_pgd_entry(kvm, pgd, start_addr);
278 }
279
280 /**
281  * unmap_stage2_range -- Clear stage2 page table entries to unmap a range
282  * @kvm:   The VM pointer
283  * @start: The intermediate physical base address of the range to unmap
284  * @size:  The size of the area to unmap
285  *
286  * Clear a range of stage-2 mappings, lowering the various ref-counts.  Must
287  * be called while holding mmu_lock (unless for freeing the stage2 pgd before
288  * destroying the VM), otherwise another faulting VCPU may come in and mess
289  * with things behind our backs.
290  */
291 static void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size)
292 {
293         pgd_t *pgd;
294         phys_addr_t addr = start, end = start + size;
295         phys_addr_t next;
296
297         assert_spin_locked(&kvm->mmu_lock);
298         pgd = kvm->arch.pgd + stage2_pgd_index(addr);
299         do {
300                 /*
301                  * Make sure the page table is still active, as another thread
302                  * could have possibly freed the page table, while we released
303                  * the lock.
304                  */
305                 if (!READ_ONCE(kvm->arch.pgd))
306                         break;
307                 next = stage2_pgd_addr_end(addr, end);
308                 if (!stage2_pgd_none(*pgd))
309                         unmap_stage2_puds(kvm, pgd, addr, next);
310                 /*
311                  * If the range is too large, release the kvm->mmu_lock
312                  * to prevent starvation and lockup detector warnings.
313                  */
314                 if (next != end)
315                         cond_resched_lock(&kvm->mmu_lock);
316         } while (pgd++, addr = next, addr != end);
317 }
318
319 static void stage2_flush_ptes(struct kvm *kvm, pmd_t *pmd,
320                               phys_addr_t addr, phys_addr_t end)
321 {
322         pte_t *pte;
323
324         pte = pte_offset_kernel(pmd, addr);
325         do {
326                 if (!pte_none(*pte) && !kvm_is_device_pfn(pte_pfn(*pte)))
327                         kvm_flush_dcache_pte(*pte);
328         } while (pte++, addr += PAGE_SIZE, addr != end);
329 }
330
331 static void stage2_flush_pmds(struct kvm *kvm, pud_t *pud,
332                               phys_addr_t addr, phys_addr_t end)
333 {
334         pmd_t *pmd;
335         phys_addr_t next;
336
337         pmd = stage2_pmd_offset(pud, addr);
338         do {
339                 next = stage2_pmd_addr_end(addr, end);
340                 if (!pmd_none(*pmd)) {
341                         if (pmd_thp_or_huge(*pmd))
342                                 kvm_flush_dcache_pmd(*pmd);
343                         else
344                                 stage2_flush_ptes(kvm, pmd, addr, next);
345                 }
346         } while (pmd++, addr = next, addr != end);
347 }
348
349 static void stage2_flush_puds(struct kvm *kvm, pgd_t *pgd,
350                               phys_addr_t addr, phys_addr_t end)
351 {
352         pud_t *pud;
353         phys_addr_t next;
354
355         pud = stage2_pud_offset(pgd, addr);
356         do {
357                 next = stage2_pud_addr_end(addr, end);
358                 if (!stage2_pud_none(*pud)) {
359                         if (stage2_pud_huge(*pud))
360                                 kvm_flush_dcache_pud(*pud);
361                         else
362                                 stage2_flush_pmds(kvm, pud, addr, next);
363                 }
364         } while (pud++, addr = next, addr != end);
365 }
366
367 static void stage2_flush_memslot(struct kvm *kvm,
368                                  struct kvm_memory_slot *memslot)
369 {
370         phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
371         phys_addr_t end = addr + PAGE_SIZE * memslot->npages;
372         phys_addr_t next;
373         pgd_t *pgd;
374
375         pgd = kvm->arch.pgd + stage2_pgd_index(addr);
376         do {
377                 next = stage2_pgd_addr_end(addr, end);
378                 stage2_flush_puds(kvm, pgd, addr, next);
379         } while (pgd++, addr = next, addr != end);
380 }
381
382 /**
383  * stage2_flush_vm - Invalidate cache for pages mapped in stage 2
384  * @kvm: The struct kvm pointer
385  *
386  * Go through the stage 2 page tables and invalidate any cache lines
387  * backing memory already mapped to the VM.
388  */
389 static void stage2_flush_vm(struct kvm *kvm)
390 {
391         struct kvm_memslots *slots;
392         struct kvm_memory_slot *memslot;
393         int idx;
394
395         idx = srcu_read_lock(&kvm->srcu);
396         spin_lock(&kvm->mmu_lock);
397
398         slots = kvm_memslots(kvm);
399         kvm_for_each_memslot(memslot, slots)
400                 stage2_flush_memslot(kvm, memslot);
401
402         spin_unlock(&kvm->mmu_lock);
403         srcu_read_unlock(&kvm->srcu, idx);
404 }
405
406 static void clear_hyp_pgd_entry(pgd_t *pgd)
407 {
408         pud_t *pud_table __maybe_unused = pud_offset(pgd, 0UL);
409         pgd_clear(pgd);
410         pud_free(NULL, pud_table);
411         put_page(virt_to_page(pgd));
412 }
413
414 static void clear_hyp_pud_entry(pud_t *pud)
415 {
416         pmd_t *pmd_table __maybe_unused = pmd_offset(pud, 0);
417         VM_BUG_ON(pud_huge(*pud));
418         pud_clear(pud);
419         pmd_free(NULL, pmd_table);
420         put_page(virt_to_page(pud));
421 }
422
423 static void clear_hyp_pmd_entry(pmd_t *pmd)
424 {
425         pte_t *pte_table = pte_offset_kernel(pmd, 0);
426         VM_BUG_ON(pmd_thp_or_huge(*pmd));
427         pmd_clear(pmd);
428         pte_free_kernel(NULL, pte_table);
429         put_page(virt_to_page(pmd));
430 }
431
432 static void unmap_hyp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end)
433 {
434         pte_t *pte, *start_pte;
435
436         start_pte = pte = pte_offset_kernel(pmd, addr);
437         do {
438                 if (!pte_none(*pte)) {
439                         kvm_set_pte(pte, __pte(0));
440                         put_page(virt_to_page(pte));
441                 }
442         } while (pte++, addr += PAGE_SIZE, addr != end);
443
444         if (hyp_pte_table_empty(start_pte))
445                 clear_hyp_pmd_entry(pmd);
446 }
447
448 static void unmap_hyp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end)
449 {
450         phys_addr_t next;
451         pmd_t *pmd, *start_pmd;
452
453         start_pmd = pmd = pmd_offset(pud, addr);
454         do {
455                 next = pmd_addr_end(addr, end);
456                 /* Hyp doesn't use huge pmds */
457                 if (!pmd_none(*pmd))
458                         unmap_hyp_ptes(pmd, addr, next);
459         } while (pmd++, addr = next, addr != end);
460
461         if (hyp_pmd_table_empty(start_pmd))
462                 clear_hyp_pud_entry(pud);
463 }
464
465 static void unmap_hyp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end)
466 {
467         phys_addr_t next;
468         pud_t *pud, *start_pud;
469
470         start_pud = pud = pud_offset(pgd, addr);
471         do {
472                 next = pud_addr_end(addr, end);
473                 /* Hyp doesn't use huge puds */
474                 if (!pud_none(*pud))
475                         unmap_hyp_pmds(pud, addr, next);
476         } while (pud++, addr = next, addr != end);
477
478         if (hyp_pud_table_empty(start_pud))
479                 clear_hyp_pgd_entry(pgd);
480 }
481
482 static void unmap_hyp_range(pgd_t *pgdp, phys_addr_t start, u64 size)
483 {
484         pgd_t *pgd;
485         phys_addr_t addr = start, end = start + size;
486         phys_addr_t next;
487
488         /*
489          * We don't unmap anything from HYP, except at the hyp tear down.
490          * Hence, we don't have to invalidate the TLBs here.
491          */
492         pgd = pgdp + pgd_index(addr);
493         do {
494                 next = pgd_addr_end(addr, end);
495                 if (!pgd_none(*pgd))
496                         unmap_hyp_puds(pgd, addr, next);
497         } while (pgd++, addr = next, addr != end);
498 }
499
500 /**
501  * free_hyp_pgds - free Hyp-mode page tables
502  *
503  * Assumes hyp_pgd is a page table used strictly in Hyp-mode and
504  * therefore contains either mappings in the kernel memory area (above
505  * PAGE_OFFSET), or device mappings in the vmalloc range (from
506  * VMALLOC_START to VMALLOC_END).
507  *
508  * boot_hyp_pgd should only map two pages for the init code.
509  */
510 void free_hyp_pgds(void)
511 {
512         unsigned long addr;
513
514         mutex_lock(&kvm_hyp_pgd_mutex);
515
516         if (boot_hyp_pgd) {
517                 unmap_hyp_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE);
518                 free_pages((unsigned long)boot_hyp_pgd, hyp_pgd_order);
519                 boot_hyp_pgd = NULL;
520         }
521
522         if (hyp_pgd) {
523                 unmap_hyp_range(hyp_pgd, hyp_idmap_start, PAGE_SIZE);
524                 for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE)
525                         unmap_hyp_range(hyp_pgd, kern_hyp_va(addr), PGDIR_SIZE);
526                 for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE)
527                         unmap_hyp_range(hyp_pgd, kern_hyp_va(addr), PGDIR_SIZE);
528
529                 free_pages((unsigned long)hyp_pgd, hyp_pgd_order);
530                 hyp_pgd = NULL;
531         }
532         if (merged_hyp_pgd) {
533                 clear_page(merged_hyp_pgd);
534                 free_page((unsigned long)merged_hyp_pgd);
535                 merged_hyp_pgd = NULL;
536         }
537
538         mutex_unlock(&kvm_hyp_pgd_mutex);
539 }
540
541 static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start,
542                                     unsigned long end, unsigned long pfn,
543                                     pgprot_t prot)
544 {
545         pte_t *pte;
546         unsigned long addr;
547
548         addr = start;
549         do {
550                 pte = pte_offset_kernel(pmd, addr);
551                 kvm_set_pte(pte, pfn_pte(pfn, prot));
552                 get_page(virt_to_page(pte));
553                 kvm_flush_dcache_to_poc(pte, sizeof(*pte));
554                 pfn++;
555         } while (addr += PAGE_SIZE, addr != end);
556 }
557
558 static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start,
559                                    unsigned long end, unsigned long pfn,
560                                    pgprot_t prot)
561 {
562         pmd_t *pmd;
563         pte_t *pte;
564         unsigned long addr, next;
565
566         addr = start;
567         do {
568                 pmd = pmd_offset(pud, addr);
569
570                 BUG_ON(pmd_sect(*pmd));
571
572                 if (pmd_none(*pmd)) {
573                         pte = pte_alloc_one_kernel(NULL, addr);
574                         if (!pte) {
575                                 kvm_err("Cannot allocate Hyp pte\n");
576                                 return -ENOMEM;
577                         }
578                         pmd_populate_kernel(NULL, pmd, pte);
579                         get_page(virt_to_page(pmd));
580                         kvm_flush_dcache_to_poc(pmd, sizeof(*pmd));
581                 }
582
583                 next = pmd_addr_end(addr, end);
584
585                 create_hyp_pte_mappings(pmd, addr, next, pfn, prot);
586                 pfn += (next - addr) >> PAGE_SHIFT;
587         } while (addr = next, addr != end);
588
589         return 0;
590 }
591
592 static int create_hyp_pud_mappings(pgd_t *pgd, unsigned long start,
593                                    unsigned long end, unsigned long pfn,
594                                    pgprot_t prot)
595 {
596         pud_t *pud;
597         pmd_t *pmd;
598         unsigned long addr, next;
599         int ret;
600
601         addr = start;
602         do {
603                 pud = pud_offset(pgd, addr);
604
605                 if (pud_none_or_clear_bad(pud)) {
606                         pmd = pmd_alloc_one(NULL, addr);
607                         if (!pmd) {
608                                 kvm_err("Cannot allocate Hyp pmd\n");
609                                 return -ENOMEM;
610                         }
611                         pud_populate(NULL, pud, pmd);
612                         get_page(virt_to_page(pud));
613                         kvm_flush_dcache_to_poc(pud, sizeof(*pud));
614                 }
615
616                 next = pud_addr_end(addr, end);
617                 ret = create_hyp_pmd_mappings(pud, addr, next, pfn, prot);
618                 if (ret)
619                         return ret;
620                 pfn += (next - addr) >> PAGE_SHIFT;
621         } while (addr = next, addr != end);
622
623         return 0;
624 }
625
626 static int __create_hyp_mappings(pgd_t *pgdp,
627                                  unsigned long start, unsigned long end,
628                                  unsigned long pfn, pgprot_t prot)
629 {
630         pgd_t *pgd;
631         pud_t *pud;
632         unsigned long addr, next;
633         int err = 0;
634
635         mutex_lock(&kvm_hyp_pgd_mutex);
636         addr = start & PAGE_MASK;
637         end = PAGE_ALIGN(end);
638         do {
639                 pgd = pgdp + pgd_index(addr);
640
641                 if (pgd_none(*pgd)) {
642                         pud = pud_alloc_one(NULL, addr);
643                         if (!pud) {
644                                 kvm_err("Cannot allocate Hyp pud\n");
645                                 err = -ENOMEM;
646                                 goto out;
647                         }
648                         pgd_populate(NULL, pgd, pud);
649                         get_page(virt_to_page(pgd));
650                         kvm_flush_dcache_to_poc(pgd, sizeof(*pgd));
651                 }
652
653                 next = pgd_addr_end(addr, end);
654                 err = create_hyp_pud_mappings(pgd, addr, next, pfn, prot);
655                 if (err)
656                         goto out;
657                 pfn += (next - addr) >> PAGE_SHIFT;
658         } while (addr = next, addr != end);
659 out:
660         mutex_unlock(&kvm_hyp_pgd_mutex);
661         return err;
662 }
663
664 static phys_addr_t kvm_kaddr_to_phys(void *kaddr)
665 {
666         if (!is_vmalloc_addr(kaddr)) {
667                 BUG_ON(!virt_addr_valid(kaddr));
668                 return __pa(kaddr);
669         } else {
670                 return page_to_phys(vmalloc_to_page(kaddr)) +
671                        offset_in_page(kaddr);
672         }
673 }
674
675 /**
676  * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode
677  * @from:       The virtual kernel start address of the range
678  * @to:         The virtual kernel end address of the range (exclusive)
679  * @prot:       The protection to be applied to this range
680  *
681  * The same virtual address as the kernel virtual address is also used
682  * in Hyp-mode mapping (modulo HYP_PAGE_OFFSET) to the same underlying
683  * physical pages.
684  */
685 int create_hyp_mappings(void *from, void *to, pgprot_t prot)
686 {
687         phys_addr_t phys_addr;
688         unsigned long virt_addr;
689         unsigned long start = kern_hyp_va((unsigned long)from);
690         unsigned long end = kern_hyp_va((unsigned long)to);
691
692         if (is_kernel_in_hyp_mode())
693                 return 0;
694
695         start = start & PAGE_MASK;
696         end = PAGE_ALIGN(end);
697
698         for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) {
699                 int err;
700
701                 phys_addr = kvm_kaddr_to_phys(from + virt_addr - start);
702                 err = __create_hyp_mappings(hyp_pgd, virt_addr,
703                                             virt_addr + PAGE_SIZE,
704                                             __phys_to_pfn(phys_addr),
705                                             prot);
706                 if (err)
707                         return err;
708         }
709
710         return 0;
711 }
712
713 /**
714  * create_hyp_io_mappings - duplicate a kernel IO mapping into Hyp mode
715  * @from:       The kernel start VA of the range
716  * @to:         The kernel end VA of the range (exclusive)
717  * @phys_addr:  The physical start address which gets mapped
718  *
719  * The resulting HYP VA is the same as the kernel VA, modulo
720  * HYP_PAGE_OFFSET.
721  */
722 int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_addr)
723 {
724         unsigned long start = kern_hyp_va((unsigned long)from);
725         unsigned long end = kern_hyp_va((unsigned long)to);
726
727         if (is_kernel_in_hyp_mode())
728                 return 0;
729
730         /* Check for a valid kernel IO mapping */
731         if (!is_vmalloc_addr(from) || !is_vmalloc_addr(to - 1))
732                 return -EINVAL;
733
734         return __create_hyp_mappings(hyp_pgd, start, end,
735                                      __phys_to_pfn(phys_addr), PAGE_HYP_DEVICE);
736 }
737
738 /**
739  * kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation.
740  * @kvm:        The KVM struct pointer for the VM.
741  *
742  * Allocates only the stage-2 HW PGD level table(s) (can support either full
743  * 40-bit input addresses or limited to 32-bit input addresses). Clears the
744  * allocated pages.
745  *
746  * Note we don't need locking here as this is only called when the VM is
747  * created, which can only be done once.
748  */
749 int kvm_alloc_stage2_pgd(struct kvm *kvm)
750 {
751         pgd_t *pgd;
752
753         if (kvm->arch.pgd != NULL) {
754                 kvm_err("kvm_arch already initialized?\n");
755                 return -EINVAL;
756         }
757
758         /* Allocate the HW PGD, making sure that each page gets its own refcount */
759         pgd = alloc_pages_exact(S2_PGD_SIZE, GFP_KERNEL | __GFP_ZERO);
760         if (!pgd)
761                 return -ENOMEM;
762
763         kvm->arch.pgd = pgd;
764         return 0;
765 }
766
767 static void stage2_unmap_memslot(struct kvm *kvm,
768                                  struct kvm_memory_slot *memslot)
769 {
770         hva_t hva = memslot->userspace_addr;
771         phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
772         phys_addr_t size = PAGE_SIZE * memslot->npages;
773         hva_t reg_end = hva + size;
774
775         /*
776          * A memory region could potentially cover multiple VMAs, and any holes
777          * between them, so iterate over all of them to find out if we should
778          * unmap any of them.
779          *
780          *     +--------------------------------------------+
781          * +---------------+----------------+   +----------------+
782          * |   : VMA 1     |      VMA 2     |   |    VMA 3  :    |
783          * +---------------+----------------+   +----------------+
784          *     |               memory region                |
785          *     +--------------------------------------------+
786          */
787         do {
788                 struct vm_area_struct *vma = find_vma(current->mm, hva);
789                 hva_t vm_start, vm_end;
790
791                 if (!vma || vma->vm_start >= reg_end)
792                         break;
793
794                 /*
795                  * Take the intersection of this VMA with the memory region
796                  */
797                 vm_start = max(hva, vma->vm_start);
798                 vm_end = min(reg_end, vma->vm_end);
799
800                 if (!(vma->vm_flags & VM_PFNMAP)) {
801                         gpa_t gpa = addr + (vm_start - memslot->userspace_addr);
802                         unmap_stage2_range(kvm, gpa, vm_end - vm_start);
803                 }
804                 hva = vm_end;
805         } while (hva < reg_end);
806 }
807
808 /**
809  * stage2_unmap_vm - Unmap Stage-2 RAM mappings
810  * @kvm: The struct kvm pointer
811  *
812  * Go through the memregions and unmap any reguler RAM
813  * backing memory already mapped to the VM.
814  */
815 void stage2_unmap_vm(struct kvm *kvm)
816 {
817         struct kvm_memslots *slots;
818         struct kvm_memory_slot *memslot;
819         int idx;
820
821         idx = srcu_read_lock(&kvm->srcu);
822         down_read(&current->mm->mmap_sem);
823         spin_lock(&kvm->mmu_lock);
824
825         slots = kvm_memslots(kvm);
826         kvm_for_each_memslot(memslot, slots)
827                 stage2_unmap_memslot(kvm, memslot);
828
829         spin_unlock(&kvm->mmu_lock);
830         up_read(&current->mm->mmap_sem);
831         srcu_read_unlock(&kvm->srcu, idx);
832 }
833
834 /**
835  * kvm_free_stage2_pgd - free all stage-2 tables
836  * @kvm:        The KVM struct pointer for the VM.
837  *
838  * Walks the level-1 page table pointed to by kvm->arch.pgd and frees all
839  * underlying level-2 and level-3 tables before freeing the actual level-1 table
840  * and setting the struct pointer to NULL.
841  */
842 void kvm_free_stage2_pgd(struct kvm *kvm)
843 {
844         void *pgd = NULL;
845
846         spin_lock(&kvm->mmu_lock);
847         if (kvm->arch.pgd) {
848                 unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE);
849                 pgd = READ_ONCE(kvm->arch.pgd);
850                 kvm->arch.pgd = NULL;
851         }
852         spin_unlock(&kvm->mmu_lock);
853
854         /* Free the HW pgd, one page at a time */
855         if (pgd)
856                 free_pages_exact(pgd, S2_PGD_SIZE);
857 }
858
859 static pud_t *stage2_get_pud(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
860                              phys_addr_t addr)
861 {
862         pgd_t *pgd;
863         pud_t *pud;
864
865         pgd = kvm->arch.pgd + stage2_pgd_index(addr);
866         if (WARN_ON(stage2_pgd_none(*pgd))) {
867                 if (!cache)
868                         return NULL;
869                 pud = mmu_memory_cache_alloc(cache);
870                 stage2_pgd_populate(pgd, pud);
871                 get_page(virt_to_page(pgd));
872         }
873
874         return stage2_pud_offset(pgd, addr);
875 }
876
877 static pmd_t *stage2_get_pmd(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
878                              phys_addr_t addr)
879 {
880         pud_t *pud;
881         pmd_t *pmd;
882
883         pud = stage2_get_pud(kvm, cache, addr);
884         if (!pud)
885                 return NULL;
886
887         if (stage2_pud_none(*pud)) {
888                 if (!cache)
889                         return NULL;
890                 pmd = mmu_memory_cache_alloc(cache);
891                 stage2_pud_populate(pud, pmd);
892                 get_page(virt_to_page(pud));
893         }
894
895         return stage2_pmd_offset(pud, addr);
896 }
897
898 static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache
899                                *cache, phys_addr_t addr, const pmd_t *new_pmd)
900 {
901         pmd_t *pmd, old_pmd;
902
903         pmd = stage2_get_pmd(kvm, cache, addr);
904         VM_BUG_ON(!pmd);
905
906         /*
907          * Mapping in huge pages should only happen through a fault.  If a
908          * page is merged into a transparent huge page, the individual
909          * subpages of that huge page should be unmapped through MMU
910          * notifiers before we get here.
911          *
912          * Merging of CompoundPages is not supported; they should become
913          * splitting first, unmapped, merged, and mapped back in on-demand.
914          */
915         VM_BUG_ON(pmd_present(*pmd) && pmd_pfn(*pmd) != pmd_pfn(*new_pmd));
916
917         old_pmd = *pmd;
918         if (pmd_present(old_pmd)) {
919                 pmd_clear(pmd);
920                 kvm_tlb_flush_vmid_ipa(kvm, addr);
921         } else {
922                 get_page(virt_to_page(pmd));
923         }
924
925         kvm_set_pmd(pmd, *new_pmd);
926         return 0;
927 }
928
929 static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
930                           phys_addr_t addr, const pte_t *new_pte,
931                           unsigned long flags)
932 {
933         pmd_t *pmd;
934         pte_t *pte, old_pte;
935         bool iomap = flags & KVM_S2PTE_FLAG_IS_IOMAP;
936         bool logging_active = flags & KVM_S2_FLAG_LOGGING_ACTIVE;
937
938         VM_BUG_ON(logging_active && !cache);
939
940         /* Create stage-2 page table mapping - Levels 0 and 1 */
941         pmd = stage2_get_pmd(kvm, cache, addr);
942         if (!pmd) {
943                 /*
944                  * Ignore calls from kvm_set_spte_hva for unallocated
945                  * address ranges.
946                  */
947                 return 0;
948         }
949
950         /*
951          * While dirty page logging - dissolve huge PMD, then continue on to
952          * allocate page.
953          */
954         if (logging_active)
955                 stage2_dissolve_pmd(kvm, addr, pmd);
956
957         /* Create stage-2 page mappings - Level 2 */
958         if (pmd_none(*pmd)) {
959                 if (!cache)
960                         return 0; /* ignore calls from kvm_set_spte_hva */
961                 pte = mmu_memory_cache_alloc(cache);
962                 pmd_populate_kernel(NULL, pmd, pte);
963                 get_page(virt_to_page(pmd));
964         }
965
966         pte = pte_offset_kernel(pmd, addr);
967
968         if (iomap && pte_present(*pte))
969                 return -EFAULT;
970
971         /* Create 2nd stage page table mapping - Level 3 */
972         old_pte = *pte;
973         if (pte_present(old_pte)) {
974                 kvm_set_pte(pte, __pte(0));
975                 kvm_tlb_flush_vmid_ipa(kvm, addr);
976         } else {
977                 get_page(virt_to_page(pte));
978         }
979
980         kvm_set_pte(pte, *new_pte);
981         return 0;
982 }
983
984 #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
985 static int stage2_ptep_test_and_clear_young(pte_t *pte)
986 {
987         if (pte_young(*pte)) {
988                 *pte = pte_mkold(*pte);
989                 return 1;
990         }
991         return 0;
992 }
993 #else
994 static int stage2_ptep_test_and_clear_young(pte_t *pte)
995 {
996         return __ptep_test_and_clear_young(pte);
997 }
998 #endif
999
1000 static int stage2_pmdp_test_and_clear_young(pmd_t *pmd)
1001 {
1002         return stage2_ptep_test_and_clear_young((pte_t *)pmd);
1003 }
1004
1005 /**
1006  * kvm_phys_addr_ioremap - map a device range to guest IPA
1007  *
1008  * @kvm:        The KVM pointer
1009  * @guest_ipa:  The IPA at which to insert the mapping
1010  * @pa:         The physical address of the device
1011  * @size:       The size of the mapping
1012  */
1013 int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
1014                           phys_addr_t pa, unsigned long size, bool writable)
1015 {
1016         phys_addr_t addr, end;
1017         int ret = 0;
1018         unsigned long pfn;
1019         struct kvm_mmu_memory_cache cache = { 0, };
1020
1021         end = (guest_ipa + size + PAGE_SIZE - 1) & PAGE_MASK;
1022         pfn = __phys_to_pfn(pa);
1023
1024         for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) {
1025                 pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE);
1026
1027                 if (writable)
1028                         pte = kvm_s2pte_mkwrite(pte);
1029
1030                 ret = mmu_topup_memory_cache(&cache, KVM_MMU_CACHE_MIN_PAGES,
1031                                                 KVM_NR_MEM_OBJS);
1032                 if (ret)
1033                         goto out;
1034                 spin_lock(&kvm->mmu_lock);
1035                 ret = stage2_set_pte(kvm, &cache, addr, &pte,
1036                                                 KVM_S2PTE_FLAG_IS_IOMAP);
1037                 spin_unlock(&kvm->mmu_lock);
1038                 if (ret)
1039                         goto out;
1040
1041                 pfn++;
1042         }
1043
1044 out:
1045         mmu_free_memory_cache(&cache);
1046         return ret;
1047 }
1048
1049 static bool transparent_hugepage_adjust(kvm_pfn_t *pfnp, phys_addr_t *ipap)
1050 {
1051         kvm_pfn_t pfn = *pfnp;
1052         gfn_t gfn = *ipap >> PAGE_SHIFT;
1053
1054         if (PageTransCompoundMap(pfn_to_page(pfn))) {
1055                 unsigned long mask;
1056                 /*
1057                  * The address we faulted on is backed by a transparent huge
1058                  * page.  However, because we map the compound huge page and
1059                  * not the individual tail page, we need to transfer the
1060                  * refcount to the head page.  We have to be careful that the
1061                  * THP doesn't start to split while we are adjusting the
1062                  * refcounts.
1063                  *
1064                  * We are sure this doesn't happen, because mmu_notifier_retry
1065                  * was successful and we are holding the mmu_lock, so if this
1066                  * THP is trying to split, it will be blocked in the mmu
1067                  * notifier before touching any of the pages, specifically
1068                  * before being able to call __split_huge_page_refcount().
1069                  *
1070                  * We can therefore safely transfer the refcount from PG_tail
1071                  * to PG_head and switch the pfn from a tail page to the head
1072                  * page accordingly.
1073                  */
1074                 mask = PTRS_PER_PMD - 1;
1075                 VM_BUG_ON((gfn & mask) != (pfn & mask));
1076                 if (pfn & mask) {
1077                         *ipap &= PMD_MASK;
1078                         kvm_release_pfn_clean(pfn);
1079                         pfn &= ~mask;
1080                         kvm_get_pfn(pfn);
1081                         *pfnp = pfn;
1082                 }
1083
1084                 return true;
1085         }
1086
1087         return false;
1088 }
1089
1090 static bool kvm_is_write_fault(struct kvm_vcpu *vcpu)
1091 {
1092         if (kvm_vcpu_trap_is_iabt(vcpu))
1093                 return false;
1094
1095         return kvm_vcpu_dabt_iswrite(vcpu);
1096 }
1097
1098 /**
1099  * stage2_wp_ptes - write protect PMD range
1100  * @pmd:        pointer to pmd entry
1101  * @addr:       range start address
1102  * @end:        range end address
1103  */
1104 static void stage2_wp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end)
1105 {
1106         pte_t *pte;
1107
1108         pte = pte_offset_kernel(pmd, addr);
1109         do {
1110                 if (!pte_none(*pte)) {
1111                         if (!kvm_s2pte_readonly(pte))
1112                                 kvm_set_s2pte_readonly(pte);
1113                 }
1114         } while (pte++, addr += PAGE_SIZE, addr != end);
1115 }
1116
1117 /**
1118  * stage2_wp_pmds - write protect PUD range
1119  * @pud:        pointer to pud entry
1120  * @addr:       range start address
1121  * @end:        range end address
1122  */
1123 static void stage2_wp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end)
1124 {
1125         pmd_t *pmd;
1126         phys_addr_t next;
1127
1128         pmd = stage2_pmd_offset(pud, addr);
1129
1130         do {
1131                 next = stage2_pmd_addr_end(addr, end);
1132                 if (!pmd_none(*pmd)) {
1133                         if (pmd_thp_or_huge(*pmd)) {
1134                                 if (!kvm_s2pmd_readonly(pmd))
1135                                         kvm_set_s2pmd_readonly(pmd);
1136                         } else {
1137                                 stage2_wp_ptes(pmd, addr, next);
1138                         }
1139                 }
1140         } while (pmd++, addr = next, addr != end);
1141 }
1142
1143 /**
1144   * stage2_wp_puds - write protect PGD range
1145   * @pgd:       pointer to pgd entry
1146   * @addr:      range start address
1147   * @end:       range end address
1148   *
1149   * Process PUD entries, for a huge PUD we cause a panic.
1150   */
1151 static void  stage2_wp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end)
1152 {
1153         pud_t *pud;
1154         phys_addr_t next;
1155
1156         pud = stage2_pud_offset(pgd, addr);
1157         do {
1158                 next = stage2_pud_addr_end(addr, end);
1159                 if (!stage2_pud_none(*pud)) {
1160                         /* TODO:PUD not supported, revisit later if supported */
1161                         BUG_ON(stage2_pud_huge(*pud));
1162                         stage2_wp_pmds(pud, addr, next);
1163                 }
1164         } while (pud++, addr = next, addr != end);
1165 }
1166
1167 /**
1168  * stage2_wp_range() - write protect stage2 memory region range
1169  * @kvm:        The KVM pointer
1170  * @addr:       Start address of range
1171  * @end:        End address of range
1172  */
1173 static void stage2_wp_range(struct kvm *kvm, phys_addr_t addr, phys_addr_t end)
1174 {
1175         pgd_t *pgd;
1176         phys_addr_t next;
1177
1178         pgd = kvm->arch.pgd + stage2_pgd_index(addr);
1179         do {
1180                 /*
1181                  * Release kvm_mmu_lock periodically if the memory region is
1182                  * large. Otherwise, we may see kernel panics with
1183                  * CONFIG_DETECT_HUNG_TASK, CONFIG_LOCKUP_DETECTOR,
1184                  * CONFIG_LOCKDEP. Additionally, holding the lock too long
1185                  * will also starve other vCPUs. We have to also make sure
1186                  * that the page tables are not freed while we released
1187                  * the lock.
1188                  */
1189                 cond_resched_lock(&kvm->mmu_lock);
1190                 if (!READ_ONCE(kvm->arch.pgd))
1191                         break;
1192                 next = stage2_pgd_addr_end(addr, end);
1193                 if (stage2_pgd_present(*pgd))
1194                         stage2_wp_puds(pgd, addr, next);
1195         } while (pgd++, addr = next, addr != end);
1196 }
1197
1198 /**
1199  * kvm_mmu_wp_memory_region() - write protect stage 2 entries for memory slot
1200  * @kvm:        The KVM pointer
1201  * @slot:       The memory slot to write protect
1202  *
1203  * Called to start logging dirty pages after memory region
1204  * KVM_MEM_LOG_DIRTY_PAGES operation is called. After this function returns
1205  * all present PMD and PTEs are write protected in the memory region.
1206  * Afterwards read of dirty page log can be called.
1207  *
1208  * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired,
1209  * serializing operations for VM memory regions.
1210  */
1211 void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot)
1212 {
1213         struct kvm_memslots *slots = kvm_memslots(kvm);
1214         struct kvm_memory_slot *memslot = id_to_memslot(slots, slot);
1215         phys_addr_t start = memslot->base_gfn << PAGE_SHIFT;
1216         phys_addr_t end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT;
1217
1218         spin_lock(&kvm->mmu_lock);
1219         stage2_wp_range(kvm, start, end);
1220         spin_unlock(&kvm->mmu_lock);
1221         kvm_flush_remote_tlbs(kvm);
1222 }
1223
1224 /**
1225  * kvm_mmu_write_protect_pt_masked() - write protect dirty pages
1226  * @kvm:        The KVM pointer
1227  * @slot:       The memory slot associated with mask
1228  * @gfn_offset: The gfn offset in memory slot
1229  * @mask:       The mask of dirty pages at offset 'gfn_offset' in this memory
1230  *              slot to be write protected
1231  *
1232  * Walks bits set in mask write protects the associated pte's. Caller must
1233  * acquire kvm_mmu_lock.
1234  */
1235 static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm,
1236                 struct kvm_memory_slot *slot,
1237                 gfn_t gfn_offset, unsigned long mask)
1238 {
1239         phys_addr_t base_gfn = slot->base_gfn + gfn_offset;
1240         phys_addr_t start = (base_gfn +  __ffs(mask)) << PAGE_SHIFT;
1241         phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT;
1242
1243         stage2_wp_range(kvm, start, end);
1244 }
1245
1246 /*
1247  * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected
1248  * dirty pages.
1249  *
1250  * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to
1251  * enable dirty logging for them.
1252  */
1253 void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
1254                 struct kvm_memory_slot *slot,
1255                 gfn_t gfn_offset, unsigned long mask)
1256 {
1257         kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
1258 }
1259
1260 static void coherent_cache_guest_page(struct kvm_vcpu *vcpu, kvm_pfn_t pfn,
1261                                       unsigned long size)
1262 {
1263         __coherent_cache_guest_page(vcpu, pfn, size);
1264 }
1265
1266 static void kvm_send_hwpoison_signal(unsigned long address,
1267                                      struct vm_area_struct *vma)
1268 {
1269         siginfo_t info;
1270
1271         info.si_signo   = SIGBUS;
1272         info.si_errno   = 0;
1273         info.si_code    = BUS_MCEERR_AR;
1274         info.si_addr    = (void __user *)address;
1275
1276         if (is_vm_hugetlb_page(vma))
1277                 info.si_addr_lsb = huge_page_shift(hstate_vma(vma));
1278         else
1279                 info.si_addr_lsb = PAGE_SHIFT;
1280
1281         send_sig_info(SIGBUS, &info, current);
1282 }
1283
1284 static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
1285                           struct kvm_memory_slot *memslot, unsigned long hva,
1286                           unsigned long fault_status)
1287 {
1288         int ret;
1289         bool write_fault, writable, hugetlb = false, force_pte = false;
1290         unsigned long mmu_seq;
1291         gfn_t gfn = fault_ipa >> PAGE_SHIFT;
1292         struct kvm *kvm = vcpu->kvm;
1293         struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
1294         struct vm_area_struct *vma;
1295         kvm_pfn_t pfn;
1296         pgprot_t mem_type = PAGE_S2;
1297         bool logging_active = memslot_is_logging(memslot);
1298         unsigned long flags = 0;
1299
1300         write_fault = kvm_is_write_fault(vcpu);
1301         if (fault_status == FSC_PERM && !write_fault) {
1302                 kvm_err("Unexpected L2 read permission error\n");
1303                 return -EFAULT;
1304         }
1305
1306         /* Let's check if we will get back a huge page backed by hugetlbfs */
1307         down_read(&current->mm->mmap_sem);
1308         vma = find_vma_intersection(current->mm, hva, hva + 1);
1309         if (unlikely(!vma)) {
1310                 kvm_err("Failed to find VMA for hva 0x%lx\n", hva);
1311                 up_read(&current->mm->mmap_sem);
1312                 return -EFAULT;
1313         }
1314
1315         if (is_vm_hugetlb_page(vma) && !logging_active) {
1316                 hugetlb = true;
1317                 gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT;
1318         } else {
1319                 /*
1320                  * Pages belonging to memslots that don't have the same
1321                  * alignment for userspace and IPA cannot be mapped using
1322                  * block descriptors even if the pages belong to a THP for
1323                  * the process, because the stage-2 block descriptor will
1324                  * cover more than a single THP and we loose atomicity for
1325                  * unmapping, updates, and splits of the THP or other pages
1326                  * in the stage-2 block range.
1327                  */
1328                 if ((memslot->userspace_addr & ~PMD_MASK) !=
1329                     ((memslot->base_gfn << PAGE_SHIFT) & ~PMD_MASK))
1330                         force_pte = true;
1331         }
1332         up_read(&current->mm->mmap_sem);
1333
1334         /* We need minimum second+third level pages */
1335         ret = mmu_topup_memory_cache(memcache, KVM_MMU_CACHE_MIN_PAGES,
1336                                      KVM_NR_MEM_OBJS);
1337         if (ret)
1338                 return ret;
1339
1340         mmu_seq = vcpu->kvm->mmu_notifier_seq;
1341         /*
1342          * Ensure the read of mmu_notifier_seq happens before we call
1343          * gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk
1344          * the page we just got a reference to gets unmapped before we have a
1345          * chance to grab the mmu_lock, which ensure that if the page gets
1346          * unmapped afterwards, the call to kvm_unmap_hva will take it away
1347          * from us again properly. This smp_rmb() interacts with the smp_wmb()
1348          * in kvm_mmu_notifier_invalidate_<page|range_end>.
1349          */
1350         smp_rmb();
1351
1352         pfn = gfn_to_pfn_prot(kvm, gfn, write_fault, &writable);
1353         if (pfn == KVM_PFN_ERR_HWPOISON) {
1354                 kvm_send_hwpoison_signal(hva, vma);
1355                 return 0;
1356         }
1357         if (is_error_noslot_pfn(pfn))
1358                 return -EFAULT;
1359
1360         if (kvm_is_device_pfn(pfn)) {
1361                 mem_type = PAGE_S2_DEVICE;
1362                 flags |= KVM_S2PTE_FLAG_IS_IOMAP;
1363         } else if (logging_active) {
1364                 /*
1365                  * Faults on pages in a memslot with logging enabled
1366                  * should not be mapped with huge pages (it introduces churn
1367                  * and performance degradation), so force a pte mapping.
1368                  */
1369                 force_pte = true;
1370                 flags |= KVM_S2_FLAG_LOGGING_ACTIVE;
1371
1372                 /*
1373                  * Only actually map the page as writable if this was a write
1374                  * fault.
1375                  */
1376                 if (!write_fault)
1377                         writable = false;
1378         }
1379
1380         spin_lock(&kvm->mmu_lock);
1381         if (mmu_notifier_retry(kvm, mmu_seq))
1382                 goto out_unlock;
1383
1384         if (!hugetlb && !force_pte)
1385                 hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa);
1386
1387         if (hugetlb) {
1388                 pmd_t new_pmd = pfn_pmd(pfn, mem_type);
1389                 new_pmd = pmd_mkhuge(new_pmd);
1390                 if (writable) {
1391                         new_pmd = kvm_s2pmd_mkwrite(new_pmd);
1392                         kvm_set_pfn_dirty(pfn);
1393                 }
1394                 coherent_cache_guest_page(vcpu, pfn, PMD_SIZE);
1395                 ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd);
1396         } else {
1397                 pte_t new_pte = pfn_pte(pfn, mem_type);
1398
1399                 if (writable) {
1400                         new_pte = kvm_s2pte_mkwrite(new_pte);
1401                         kvm_set_pfn_dirty(pfn);
1402                         mark_page_dirty(kvm, gfn);
1403                 }
1404                 coherent_cache_guest_page(vcpu, pfn, PAGE_SIZE);
1405                 ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, flags);
1406         }
1407
1408 out_unlock:
1409         spin_unlock(&kvm->mmu_lock);
1410         kvm_set_pfn_accessed(pfn);
1411         kvm_release_pfn_clean(pfn);
1412         return ret;
1413 }
1414
1415 /*
1416  * Resolve the access fault by making the page young again.
1417  * Note that because the faulting entry is guaranteed not to be
1418  * cached in the TLB, we don't need to invalidate anything.
1419  * Only the HW Access Flag updates are supported for Stage 2 (no DBM),
1420  * so there is no need for atomic (pte|pmd)_mkyoung operations.
1421  */
1422 static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
1423 {
1424         pmd_t *pmd;
1425         pte_t *pte;
1426         kvm_pfn_t pfn;
1427         bool pfn_valid = false;
1428
1429         trace_kvm_access_fault(fault_ipa);
1430
1431         spin_lock(&vcpu->kvm->mmu_lock);
1432
1433         pmd = stage2_get_pmd(vcpu->kvm, NULL, fault_ipa);
1434         if (!pmd || pmd_none(*pmd))     /* Nothing there */
1435                 goto out;
1436
1437         if (pmd_thp_or_huge(*pmd)) {    /* THP, HugeTLB */
1438                 *pmd = pmd_mkyoung(*pmd);
1439                 pfn = pmd_pfn(*pmd);
1440                 pfn_valid = true;
1441                 goto out;
1442         }
1443
1444         pte = pte_offset_kernel(pmd, fault_ipa);
1445         if (pte_none(*pte))             /* Nothing there either */
1446                 goto out;
1447
1448         *pte = pte_mkyoung(*pte);       /* Just a page... */
1449         pfn = pte_pfn(*pte);
1450         pfn_valid = true;
1451 out:
1452         spin_unlock(&vcpu->kvm->mmu_lock);
1453         if (pfn_valid)
1454                 kvm_set_pfn_accessed(pfn);
1455 }
1456
1457 /**
1458  * kvm_handle_guest_abort - handles all 2nd stage aborts
1459  * @vcpu:       the VCPU pointer
1460  * @run:        the kvm_run structure
1461  *
1462  * Any abort that gets to the host is almost guaranteed to be caused by a
1463  * missing second stage translation table entry, which can mean that either the
1464  * guest simply needs more memory and we must allocate an appropriate page or it
1465  * can mean that the guest tried to access I/O memory, which is emulated by user
1466  * space. The distinction is based on the IPA causing the fault and whether this
1467  * memory region has been registered as standard RAM by user space.
1468  */
1469 int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
1470 {
1471         unsigned long fault_status;
1472         phys_addr_t fault_ipa;
1473         struct kvm_memory_slot *memslot;
1474         unsigned long hva;
1475         bool is_iabt, write_fault, writable;
1476         gfn_t gfn;
1477         int ret, idx;
1478
1479         fault_status = kvm_vcpu_trap_get_fault_type(vcpu);
1480
1481         fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
1482         is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
1483
1484         /* Synchronous External Abort? */
1485         if (kvm_vcpu_dabt_isextabt(vcpu)) {
1486                 /*
1487                  * For RAS the host kernel may handle this abort.
1488                  * There is no need to pass the error into the guest.
1489                  */
1490                 if (!handle_guest_sea(fault_ipa, kvm_vcpu_get_hsr(vcpu)))
1491                         return 1;
1492
1493                 if (unlikely(!is_iabt)) {
1494                         kvm_inject_vabt(vcpu);
1495                         return 1;
1496                 }
1497         }
1498
1499         trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_hsr(vcpu),
1500                               kvm_vcpu_get_hfar(vcpu), fault_ipa);
1501
1502         /* Check the stage-2 fault is trans. fault or write fault */
1503         if (fault_status != FSC_FAULT && fault_status != FSC_PERM &&
1504             fault_status != FSC_ACCESS) {
1505                 kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n",
1506                         kvm_vcpu_trap_get_class(vcpu),
1507                         (unsigned long)kvm_vcpu_trap_get_fault(vcpu),
1508                         (unsigned long)kvm_vcpu_get_hsr(vcpu));
1509                 return -EFAULT;
1510         }
1511
1512         idx = srcu_read_lock(&vcpu->kvm->srcu);
1513
1514         gfn = fault_ipa >> PAGE_SHIFT;
1515         memslot = gfn_to_memslot(vcpu->kvm, gfn);
1516         hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
1517         write_fault = kvm_is_write_fault(vcpu);
1518         if (kvm_is_error_hva(hva) || (write_fault && !writable)) {
1519                 if (is_iabt) {
1520                         /* Prefetch Abort on I/O address */
1521                         kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu));
1522                         ret = 1;
1523                         goto out_unlock;
1524                 }
1525
1526                 /*
1527                  * Check for a cache maintenance operation. Since we
1528                  * ended-up here, we know it is outside of any memory
1529                  * slot. But we can't find out if that is for a device,
1530                  * or if the guest is just being stupid. The only thing
1531                  * we know for sure is that this range cannot be cached.
1532                  *
1533                  * So let's assume that the guest is just being
1534                  * cautious, and skip the instruction.
1535                  */
1536                 if (kvm_vcpu_dabt_is_cm(vcpu)) {
1537                         kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
1538                         ret = 1;
1539                         goto out_unlock;
1540                 }
1541
1542                 /*
1543                  * The IPA is reported as [MAX:12], so we need to
1544                  * complement it with the bottom 12 bits from the
1545                  * faulting VA. This is always 12 bits, irrespective
1546                  * of the page size.
1547                  */
1548                 fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ((1 << 12) - 1);
1549                 ret = io_mem_abort(vcpu, run, fault_ipa);
1550                 goto out_unlock;
1551         }
1552
1553         /* Userspace should not be able to register out-of-bounds IPAs */
1554         VM_BUG_ON(fault_ipa >= KVM_PHYS_SIZE);
1555
1556         if (fault_status == FSC_ACCESS) {
1557                 handle_access_fault(vcpu, fault_ipa);
1558                 ret = 1;
1559                 goto out_unlock;
1560         }
1561
1562         ret = user_mem_abort(vcpu, fault_ipa, memslot, hva, fault_status);
1563         if (ret == 0)
1564                 ret = 1;
1565 out_unlock:
1566         srcu_read_unlock(&vcpu->kvm->srcu, idx);
1567         return ret;
1568 }
1569
1570 static int handle_hva_to_gpa(struct kvm *kvm,
1571                              unsigned long start,
1572                              unsigned long end,
1573                              int (*handler)(struct kvm *kvm,
1574                                             gpa_t gpa, u64 size,
1575                                             void *data),
1576                              void *data)
1577 {
1578         struct kvm_memslots *slots;
1579         struct kvm_memory_slot *memslot;
1580         int ret = 0;
1581
1582         slots = kvm_memslots(kvm);
1583
1584         /* we only care about the pages that the guest sees */
1585         kvm_for_each_memslot(memslot, slots) {
1586                 unsigned long hva_start, hva_end;
1587                 gfn_t gpa;
1588
1589                 hva_start = max(start, memslot->userspace_addr);
1590                 hva_end = min(end, memslot->userspace_addr +
1591                                         (memslot->npages << PAGE_SHIFT));
1592                 if (hva_start >= hva_end)
1593                         continue;
1594
1595                 gpa = hva_to_gfn_memslot(hva_start, memslot) << PAGE_SHIFT;
1596                 ret |= handler(kvm, gpa, (u64)(hva_end - hva_start), data);
1597         }
1598
1599         return ret;
1600 }
1601
1602 static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
1603 {
1604         unmap_stage2_range(kvm, gpa, size);
1605         return 0;
1606 }
1607
1608 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
1609 {
1610         unsigned long end = hva + PAGE_SIZE;
1611
1612         if (!kvm->arch.pgd)
1613                 return 0;
1614
1615         trace_kvm_unmap_hva(hva);
1616         handle_hva_to_gpa(kvm, hva, end, &kvm_unmap_hva_handler, NULL);
1617         return 0;
1618 }
1619
1620 int kvm_unmap_hva_range(struct kvm *kvm,
1621                         unsigned long start, unsigned long end)
1622 {
1623         if (!kvm->arch.pgd)
1624                 return 0;
1625
1626         trace_kvm_unmap_hva_range(start, end);
1627         handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, NULL);
1628         return 0;
1629 }
1630
1631 static int kvm_set_spte_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
1632 {
1633         pte_t *pte = (pte_t *)data;
1634
1635         WARN_ON(size != PAGE_SIZE);
1636         /*
1637          * We can always call stage2_set_pte with KVM_S2PTE_FLAG_LOGGING_ACTIVE
1638          * flag clear because MMU notifiers will have unmapped a huge PMD before
1639          * calling ->change_pte() (which in turn calls kvm_set_spte_hva()) and
1640          * therefore stage2_set_pte() never needs to clear out a huge PMD
1641          * through this calling path.
1642          */
1643         stage2_set_pte(kvm, NULL, gpa, pte, 0);
1644         return 0;
1645 }
1646
1647
1648 void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
1649 {
1650         unsigned long end = hva + PAGE_SIZE;
1651         pte_t stage2_pte;
1652
1653         if (!kvm->arch.pgd)
1654                 return;
1655
1656         trace_kvm_set_spte_hva(hva);
1657         stage2_pte = pfn_pte(pte_pfn(pte), PAGE_S2);
1658         handle_hva_to_gpa(kvm, hva, end, &kvm_set_spte_handler, &stage2_pte);
1659 }
1660
1661 static int kvm_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
1662 {
1663         pmd_t *pmd;
1664         pte_t *pte;
1665
1666         WARN_ON(size != PAGE_SIZE && size != PMD_SIZE);
1667         pmd = stage2_get_pmd(kvm, NULL, gpa);
1668         if (!pmd || pmd_none(*pmd))     /* Nothing there */
1669                 return 0;
1670
1671         if (pmd_thp_or_huge(*pmd))      /* THP, HugeTLB */
1672                 return stage2_pmdp_test_and_clear_young(pmd);
1673
1674         pte = pte_offset_kernel(pmd, gpa);
1675         if (pte_none(*pte))
1676                 return 0;
1677
1678         return stage2_ptep_test_and_clear_young(pte);
1679 }
1680
1681 static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, u64 size, void *data)
1682 {
1683         pmd_t *pmd;
1684         pte_t *pte;
1685
1686         WARN_ON(size != PAGE_SIZE && size != PMD_SIZE);
1687         pmd = stage2_get_pmd(kvm, NULL, gpa);
1688         if (!pmd || pmd_none(*pmd))     /* Nothing there */
1689                 return 0;
1690
1691         if (pmd_thp_or_huge(*pmd))              /* THP, HugeTLB */
1692                 return pmd_young(*pmd);
1693
1694         pte = pte_offset_kernel(pmd, gpa);
1695         if (!pte_none(*pte))            /* Just a page... */
1696                 return pte_young(*pte);
1697
1698         return 0;
1699 }
1700
1701 int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end)
1702 {
1703         if (!kvm->arch.pgd)
1704                 return 0;
1705         trace_kvm_age_hva(start, end);
1706         return handle_hva_to_gpa(kvm, start, end, kvm_age_hva_handler, NULL);
1707 }
1708
1709 int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
1710 {
1711         if (!kvm->arch.pgd)
1712                 return 0;
1713         trace_kvm_test_age_hva(hva);
1714         return handle_hva_to_gpa(kvm, hva, hva, kvm_test_age_hva_handler, NULL);
1715 }
1716
1717 void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu)
1718 {
1719         mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
1720 }
1721
1722 phys_addr_t kvm_mmu_get_httbr(void)
1723 {
1724         if (__kvm_cpu_uses_extended_idmap())
1725                 return virt_to_phys(merged_hyp_pgd);
1726         else
1727                 return virt_to_phys(hyp_pgd);
1728 }
1729
1730 phys_addr_t kvm_get_idmap_vector(void)
1731 {
1732         return hyp_idmap_vector;
1733 }
1734
1735 static int kvm_map_idmap_text(pgd_t *pgd)
1736 {
1737         int err;
1738
1739         /* Create the idmap in the boot page tables */
1740         err =   __create_hyp_mappings(pgd,
1741                                       hyp_idmap_start, hyp_idmap_end,
1742                                       __phys_to_pfn(hyp_idmap_start),
1743                                       PAGE_HYP_EXEC);
1744         if (err)
1745                 kvm_err("Failed to idmap %lx-%lx\n",
1746                         hyp_idmap_start, hyp_idmap_end);
1747
1748         return err;
1749 }
1750
1751 int kvm_mmu_init(void)
1752 {
1753         int err;
1754
1755         hyp_idmap_start = kvm_virt_to_phys(__hyp_idmap_text_start);
1756         hyp_idmap_end = kvm_virt_to_phys(__hyp_idmap_text_end);
1757         hyp_idmap_vector = kvm_virt_to_phys(__kvm_hyp_init);
1758
1759         /*
1760          * We rely on the linker script to ensure at build time that the HYP
1761          * init code does not cross a page boundary.
1762          */
1763         BUG_ON((hyp_idmap_start ^ (hyp_idmap_end - 1)) & PAGE_MASK);
1764
1765         kvm_info("IDMAP page: %lx\n", hyp_idmap_start);
1766         kvm_info("HYP VA range: %lx:%lx\n",
1767                  kern_hyp_va(PAGE_OFFSET), kern_hyp_va(~0UL));
1768
1769         if (hyp_idmap_start >= kern_hyp_va(PAGE_OFFSET) &&
1770             hyp_idmap_start <  kern_hyp_va(~0UL) &&
1771             hyp_idmap_start != (unsigned long)__hyp_idmap_text_start) {
1772                 /*
1773                  * The idmap page is intersecting with the VA space,
1774                  * it is not safe to continue further.
1775                  */
1776                 kvm_err("IDMAP intersecting with HYP VA, unable to continue\n");
1777                 err = -EINVAL;
1778                 goto out;
1779         }
1780
1781         hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, hyp_pgd_order);
1782         if (!hyp_pgd) {
1783                 kvm_err("Hyp mode PGD not allocated\n");
1784                 err = -ENOMEM;
1785                 goto out;
1786         }
1787
1788         if (__kvm_cpu_uses_extended_idmap()) {
1789                 boot_hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
1790                                                          hyp_pgd_order);
1791                 if (!boot_hyp_pgd) {
1792                         kvm_err("Hyp boot PGD not allocated\n");
1793                         err = -ENOMEM;
1794                         goto out;
1795                 }
1796
1797                 err = kvm_map_idmap_text(boot_hyp_pgd);
1798                 if (err)
1799                         goto out;
1800
1801                 merged_hyp_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
1802                 if (!merged_hyp_pgd) {
1803                         kvm_err("Failed to allocate extra HYP pgd\n");
1804                         goto out;
1805                 }
1806                 __kvm_extend_hypmap(boot_hyp_pgd, hyp_pgd, merged_hyp_pgd,
1807                                     hyp_idmap_start);
1808         } else {
1809                 err = kvm_map_idmap_text(hyp_pgd);
1810                 if (err)
1811                         goto out;
1812         }
1813
1814         return 0;
1815 out:
1816         free_hyp_pgds();
1817         return err;
1818 }
1819
1820 void kvm_arch_commit_memory_region(struct kvm *kvm,
1821                                    const struct kvm_userspace_memory_region *mem,
1822                                    const struct kvm_memory_slot *old,
1823                                    const struct kvm_memory_slot *new,
1824                                    enum kvm_mr_change change)
1825 {
1826         /*
1827          * At this point memslot has been committed and there is an
1828          * allocated dirty_bitmap[], dirty pages will be be tracked while the
1829          * memory slot is write protected.
1830          */
1831         if (change != KVM_MR_DELETE && mem->flags & KVM_MEM_LOG_DIRTY_PAGES)
1832                 kvm_mmu_wp_memory_region(kvm, mem->slot);
1833 }
1834
1835 int kvm_arch_prepare_memory_region(struct kvm *kvm,
1836                                    struct kvm_memory_slot *memslot,
1837                                    const struct kvm_userspace_memory_region *mem,
1838                                    enum kvm_mr_change change)
1839 {
1840         hva_t hva = mem->userspace_addr;
1841         hva_t reg_end = hva + mem->memory_size;
1842         bool writable = !(mem->flags & KVM_MEM_READONLY);
1843         int ret = 0;
1844
1845         if (change != KVM_MR_CREATE && change != KVM_MR_MOVE &&
1846                         change != KVM_MR_FLAGS_ONLY)
1847                 return 0;
1848
1849         /*
1850          * Prevent userspace from creating a memory region outside of the IPA
1851          * space addressable by the KVM guest IPA space.
1852          */
1853         if (memslot->base_gfn + memslot->npages >=
1854             (KVM_PHYS_SIZE >> PAGE_SHIFT))
1855                 return -EFAULT;
1856
1857         down_read(&current->mm->mmap_sem);
1858         /*
1859          * A memory region could potentially cover multiple VMAs, and any holes
1860          * between them, so iterate over all of them to find out if we can map
1861          * any of them right now.
1862          *
1863          *     +--------------------------------------------+
1864          * +---------------+----------------+   +----------------+
1865          * |   : VMA 1     |      VMA 2     |   |    VMA 3  :    |
1866          * +---------------+----------------+   +----------------+
1867          *     |               memory region                |
1868          *     +--------------------------------------------+
1869          */
1870         do {
1871                 struct vm_area_struct *vma = find_vma(current->mm, hva);
1872                 hva_t vm_start, vm_end;
1873
1874                 if (!vma || vma->vm_start >= reg_end)
1875                         break;
1876
1877                 /*
1878                  * Mapping a read-only VMA is only allowed if the
1879                  * memory region is configured as read-only.
1880                  */
1881                 if (writable && !(vma->vm_flags & VM_WRITE)) {
1882                         ret = -EPERM;
1883                         break;
1884                 }
1885
1886                 /*
1887                  * Take the intersection of this VMA with the memory region
1888                  */
1889                 vm_start = max(hva, vma->vm_start);
1890                 vm_end = min(reg_end, vma->vm_end);
1891
1892                 if (vma->vm_flags & VM_PFNMAP) {
1893                         gpa_t gpa = mem->guest_phys_addr +
1894                                     (vm_start - mem->userspace_addr);
1895                         phys_addr_t pa;
1896
1897                         pa = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT;
1898                         pa += vm_start - vma->vm_start;
1899
1900                         /* IO region dirty page logging not allowed */
1901                         if (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES) {
1902                                 ret = -EINVAL;
1903                                 goto out;
1904                         }
1905
1906                         ret = kvm_phys_addr_ioremap(kvm, gpa, pa,
1907                                                     vm_end - vm_start,
1908                                                     writable);
1909                         if (ret)
1910                                 break;
1911                 }
1912                 hva = vm_end;
1913         } while (hva < reg_end);
1914
1915         if (change == KVM_MR_FLAGS_ONLY)
1916                 goto out;
1917
1918         spin_lock(&kvm->mmu_lock);
1919         if (ret)
1920                 unmap_stage2_range(kvm, mem->guest_phys_addr, mem->memory_size);
1921         else
1922                 stage2_flush_memslot(kvm, memslot);
1923         spin_unlock(&kvm->mmu_lock);
1924 out:
1925         up_read(&current->mm->mmap_sem);
1926         return ret;
1927 }
1928
1929 void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
1930                            struct kvm_memory_slot *dont)
1931 {
1932 }
1933
1934 int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
1935                             unsigned long npages)
1936 {
1937         return 0;
1938 }
1939
1940 void kvm_arch_memslots_updated(struct kvm *kvm, struct kvm_memslots *slots)
1941 {
1942 }
1943
1944 void kvm_arch_flush_shadow_all(struct kvm *kvm)
1945 {
1946         kvm_free_stage2_pgd(kvm);
1947 }
1948
1949 void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
1950                                    struct kvm_memory_slot *slot)
1951 {
1952         gpa_t gpa = slot->base_gfn << PAGE_SHIFT;
1953         phys_addr_t size = slot->npages << PAGE_SHIFT;
1954
1955         spin_lock(&kvm->mmu_lock);
1956         unmap_stage2_range(kvm, gpa, size);
1957         spin_unlock(&kvm->mmu_lock);
1958 }
1959
1960 /*
1961  * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
1962  *
1963  * Main problems:
1964  * - S/W ops are local to a CPU (not broadcast)
1965  * - We have line migration behind our back (speculation)
1966  * - System caches don't support S/W at all (damn!)
1967  *
1968  * In the face of the above, the best we can do is to try and convert
1969  * S/W ops to VA ops. Because the guest is not allowed to infer the
1970  * S/W to PA mapping, it can only use S/W to nuke the whole cache,
1971  * which is a rather good thing for us.
1972  *
1973  * Also, it is only used when turning caches on/off ("The expected
1974  * usage of the cache maintenance instructions that operate by set/way
1975  * is associated with the cache maintenance instructions associated
1976  * with the powerdown and powerup of caches, if this is required by
1977  * the implementation.").
1978  *
1979  * We use the following policy:
1980  *
1981  * - If we trap a S/W operation, we enable VM trapping to detect
1982  *   caches being turned on/off, and do a full clean.
1983  *
1984  * - We flush the caches on both caches being turned on and off.
1985  *
1986  * - Once the caches are enabled, we stop trapping VM ops.
1987  */
1988 void kvm_set_way_flush(struct kvm_vcpu *vcpu)
1989 {
1990         unsigned long hcr = vcpu_get_hcr(vcpu);
1991
1992         /*
1993          * If this is the first time we do a S/W operation
1994          * (i.e. HCR_TVM not set) flush the whole memory, and set the
1995          * VM trapping.
1996          *
1997          * Otherwise, rely on the VM trapping to wait for the MMU +
1998          * Caches to be turned off. At that point, we'll be able to
1999          * clean the caches again.
2000          */
2001         if (!(hcr & HCR_TVM)) {
2002                 trace_kvm_set_way_flush(*vcpu_pc(vcpu),
2003                                         vcpu_has_cache_enabled(vcpu));
2004                 stage2_flush_vm(vcpu->kvm);
2005                 vcpu_set_hcr(vcpu, hcr | HCR_TVM);
2006         }
2007 }
2008
2009 void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled)
2010 {
2011         bool now_enabled = vcpu_has_cache_enabled(vcpu);
2012
2013         /*
2014          * If switching the MMU+caches on, need to invalidate the caches.
2015          * If switching it off, need to clean the caches.
2016          * Clean + invalidate does the trick always.
2017          */
2018         if (now_enabled != was_enabled)
2019                 stage2_flush_vm(vcpu->kvm);
2020
2021         /* Caches are now on, stop trapping VM ops (until a S/W op) */
2022         if (now_enabled)
2023                 vcpu_set_hcr(vcpu, vcpu_get_hcr(vcpu) & ~HCR_TVM);
2024
2025         trace_kvm_toggle_cache(*vcpu_pc(vcpu), was_enabled, now_enabled);
2026 }