source: src/linux/universal/linux-4.9/arch/arm/kvm/mmu.c @ 31859

Last change on this file since 31859 was 31859, checked in by brainslayer, 10 days ago

kernel update

File size: 52.2 KB
Line 
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 <trace/events/kvm.h>
24#include <asm/pgalloc.h>
25#include <asm/cacheflush.h>
26#include <asm/kvm_arm.h>
27#include <asm/kvm_mmu.h>
28#include <asm/kvm_mmio.h>
29#include <asm/kvm_asm.h>
30#include <asm/kvm_emulate.h>
31#include <asm/virt.h>
32
33#include "trace.h"
34
35static pgd_t *boot_hyp_pgd;
36static pgd_t *hyp_pgd;
37static pgd_t *merged_hyp_pgd;
38static DEFINE_MUTEX(kvm_hyp_pgd_mutex);
39
40static unsigned long hyp_idmap_start;
41static unsigned long hyp_idmap_end;
42static phys_addr_t hyp_idmap_vector;
43
44#define S2_PGD_SIZE     (PTRS_PER_S2_PGD * sizeof(pgd_t))
45#define hyp_pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t))
46
47#define KVM_S2PTE_FLAG_IS_IOMAP         (1UL << 0)
48#define KVM_S2_FLAG_LOGGING_ACTIVE      (1UL << 1)
49
50static bool memslot_is_logging(struct kvm_memory_slot *memslot)
51{
52        return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY);
53}
54
55/**
56 * kvm_flush_remote_tlbs() - flush all VM TLB entries for v7/8
57 * @kvm:        pointer to kvm structure.
58 *
59 * Interface to HYP function to flush all VM TLB entries
60 */
61void kvm_flush_remote_tlbs(struct kvm *kvm)
62{
63        kvm_call_hyp(__kvm_tlb_flush_vmid, kvm);
64}
65
66static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
67{
68        kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa);
69}
70
71/*
72 * D-Cache management functions. They take the page table entries by
73 * value, as they are flushing the cache using the kernel mapping (or
74 * kmap on 32bit).
75 */
76static void kvm_flush_dcache_pte(pte_t pte)
77{
78        __kvm_flush_dcache_pte(pte);
79}
80
81static void kvm_flush_dcache_pmd(pmd_t pmd)
82{
83        __kvm_flush_dcache_pmd(pmd);
84}
85
86static void kvm_flush_dcache_pud(pud_t pud)
87{
88        __kvm_flush_dcache_pud(pud);
89}
90
91static bool kvm_is_device_pfn(unsigned long pfn)
92{
93        return !pfn_valid(pfn);
94}
95
96/**
97 * stage2_dissolve_pmd() - clear and flush huge PMD entry
98 * @kvm:        pointer to kvm structure.
99 * @addr:       IPA
100 * @pmd:        pmd pointer for IPA
101 *
102 * Function clears a PMD entry, flushes addr 1st and 2nd stage TLBs. Marks all
103 * pages in the range dirty.
104 */
105static void stage2_dissolve_pmd(struct kvm *kvm, phys_addr_t addr, pmd_t *pmd)
106{
107        if (!pmd_thp_or_huge(*pmd))
108                return;
109
110        pmd_clear(pmd);
111        kvm_tlb_flush_vmid_ipa(kvm, addr);
112        put_page(virt_to_page(pmd));
113}
114
115static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
116                                  int min, int max)
117{
118        void *page;
119
120        BUG_ON(max > KVM_NR_MEM_OBJS);
121        if (cache->nobjs >= min)
122                return 0;
123        while (cache->nobjs < max) {
124                page = (void *)__get_free_page(PGALLOC_GFP);
125                if (!page)
126                        return -ENOMEM;
127                cache->objects[cache->nobjs++] = page;
128        }
129        return 0;
130}
131
132static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
133{
134        while (mc->nobjs)
135                free_page((unsigned long)mc->objects[--mc->nobjs]);
136}
137
138static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
139{
140        void *p;
141
142        BUG_ON(!mc || !mc->nobjs);
143        p = mc->objects[--mc->nobjs];
144        return p;
145}
146
147static void clear_stage2_pgd_entry(struct kvm *kvm, pgd_t *pgd, phys_addr_t addr)
148{
149        pud_t *pud_table __maybe_unused = stage2_pud_offset(pgd, 0UL);
150        stage2_pgd_clear(pgd);
151        kvm_tlb_flush_vmid_ipa(kvm, addr);
152        stage2_pud_free(pud_table);
153        put_page(virt_to_page(pgd));
154}
155
156static void clear_stage2_pud_entry(struct kvm *kvm, pud_t *pud, phys_addr_t addr)
157{
158        pmd_t *pmd_table __maybe_unused = stage2_pmd_offset(pud, 0);
159        VM_BUG_ON(stage2_pud_huge(*pud));
160        stage2_pud_clear(pud);
161        kvm_tlb_flush_vmid_ipa(kvm, addr);
162        stage2_pmd_free(pmd_table);
163        put_page(virt_to_page(pud));
164}
165
166static void clear_stage2_pmd_entry(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr)
167{
168        pte_t *pte_table = pte_offset_kernel(pmd, 0);
169        VM_BUG_ON(pmd_thp_or_huge(*pmd));
170        pmd_clear(pmd);
171        kvm_tlb_flush_vmid_ipa(kvm, addr);
172        pte_free_kernel(NULL, pte_table);
173        put_page(virt_to_page(pmd));
174}
175
176/*
177 * Unmapping vs dcache management:
178 *
179 * If a guest maps certain memory pages as uncached, all writes will
180 * bypass the data cache and go directly to RAM.  However, the CPUs
181 * can still speculate reads (not writes) and fill cache lines with
182 * data.
183 *
184 * Those cache lines will be *clean* cache lines though, so a
185 * clean+invalidate operation is equivalent to an invalidate
186 * operation, because no cache lines are marked dirty.
187 *
188 * Those clean cache lines could be filled prior to an uncached write
189 * by the guest, and the cache coherent IO subsystem would therefore
190 * end up writing old data to disk.
191 *
192 * This is why right after unmapping a page/section and invalidating
193 * the corresponding TLBs, we call kvm_flush_dcache_p*() to make sure
194 * the IO subsystem will never hit in the cache.
195 */
196static void unmap_stage2_ptes(struct kvm *kvm, pmd_t *pmd,
197                       phys_addr_t addr, phys_addr_t end)
198{
199        phys_addr_t start_addr = addr;
200        pte_t *pte, *start_pte;
201
202        start_pte = pte = pte_offset_kernel(pmd, addr);
203        do {
204                if (!pte_none(*pte)) {
205                        pte_t old_pte = *pte;
206
207                        kvm_set_pte(pte, __pte(0));
208                        kvm_tlb_flush_vmid_ipa(kvm, addr);
209
210                        /* No need to invalidate the cache for device mappings */
211                        if (!kvm_is_device_pfn(pte_pfn(old_pte)))
212                                kvm_flush_dcache_pte(old_pte);
213
214                        put_page(virt_to_page(pte));
215                }
216        } while (pte++, addr += PAGE_SIZE, addr != end);
217
218        if (stage2_pte_table_empty(start_pte))
219                clear_stage2_pmd_entry(kvm, pmd, start_addr);
220}
221
222static void unmap_stage2_pmds(struct kvm *kvm, pud_t *pud,
223                       phys_addr_t addr, phys_addr_t end)
224{
225        phys_addr_t next, start_addr = addr;
226        pmd_t *pmd, *start_pmd;
227
228        start_pmd = pmd = stage2_pmd_offset(pud, addr);
229        do {
230                next = stage2_pmd_addr_end(addr, end);
231                if (!pmd_none(*pmd)) {
232                        if (pmd_thp_or_huge(*pmd)) {
233                                pmd_t old_pmd = *pmd;
234
235                                pmd_clear(pmd);
236                                kvm_tlb_flush_vmid_ipa(kvm, addr);
237
238                                kvm_flush_dcache_pmd(old_pmd);
239
240                                put_page(virt_to_page(pmd));
241                        } else {
242                                unmap_stage2_ptes(kvm, pmd, addr, next);
243                        }
244                }
245        } while (pmd++, addr = next, addr != end);
246
247        if (stage2_pmd_table_empty(start_pmd))
248                clear_stage2_pud_entry(kvm, pud, start_addr);
249}
250
251static void unmap_stage2_puds(struct kvm *kvm, pgd_t *pgd,
252                       phys_addr_t addr, phys_addr_t end)
253{
254        phys_addr_t next, start_addr = addr;
255        pud_t *pud, *start_pud;
256
257        start_pud = pud = stage2_pud_offset(pgd, addr);
258        do {
259                next = stage2_pud_addr_end(addr, end);
260                if (!stage2_pud_none(*pud)) {
261                        if (stage2_pud_huge(*pud)) {
262                                pud_t old_pud = *pud;
263
264                                stage2_pud_clear(pud);
265                                kvm_tlb_flush_vmid_ipa(kvm, addr);
266                                kvm_flush_dcache_pud(old_pud);
267                                put_page(virt_to_page(pud));
268                        } else {
269                                unmap_stage2_pmds(kvm, pud, addr, next);
270                        }
271                }
272        } while (pud++, addr = next, addr != end);
273
274        if (stage2_pud_table_empty(start_pud))
275                clear_stage2_pgd_entry(kvm, pgd, start_addr);
276}
277
278/**
279 * unmap_stage2_range -- Clear stage2 page table entries to unmap a range
280 * @kvm:   The VM pointer
281 * @start: The intermediate physical base address of the range to unmap
282 * @size:  The size of the area to unmap
283 *
284 * Clear a range of stage-2 mappings, lowering the various ref-counts.  Must
285 * be called while holding mmu_lock (unless for freeing the stage2 pgd before
286 * destroying the VM), otherwise another faulting VCPU may come in and mess
287 * with things behind our backs.
288 */
289static void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size)
290{
291        pgd_t *pgd;
292        phys_addr_t addr = start, end = start + size;
293        phys_addr_t next;
294
295        assert_spin_locked(&kvm->mmu_lock);
296        pgd = kvm->arch.pgd + stage2_pgd_index(addr);
297        do {
298                next = stage2_pgd_addr_end(addr, end);
299                if (!stage2_pgd_none(*pgd))
300                        unmap_stage2_puds(kvm, pgd, addr, next);
301                /*
302                 * If the range is too large, release the kvm->mmu_lock
303                 * to prevent starvation and lockup detector warnings.
304                 */
305                if (next != end)
306                        cond_resched_lock(&kvm->mmu_lock);
307        } while (pgd++, addr = next, addr != end);
308}
309
310static void stage2_flush_ptes(struct kvm *kvm, pmd_t *pmd,
311                              phys_addr_t addr, phys_addr_t end)
312{
313        pte_t *pte;
314
315        pte = pte_offset_kernel(pmd, addr);
316        do {
317                if (!pte_none(*pte) && !kvm_is_device_pfn(pte_pfn(*pte)))
318                        kvm_flush_dcache_pte(*pte);
319        } while (pte++, addr += PAGE_SIZE, addr != end);
320}
321
322static void stage2_flush_pmds(struct kvm *kvm, pud_t *pud,
323                              phys_addr_t addr, phys_addr_t end)
324{
325        pmd_t *pmd;
326        phys_addr_t next;
327
328        pmd = stage2_pmd_offset(pud, addr);
329        do {
330                next = stage2_pmd_addr_end(addr, end);
331                if (!pmd_none(*pmd)) {
332                        if (pmd_thp_or_huge(*pmd))
333                                kvm_flush_dcache_pmd(*pmd);
334                        else
335                                stage2_flush_ptes(kvm, pmd, addr, next);
336                }
337        } while (pmd++, addr = next, addr != end);
338}
339
340static void stage2_flush_puds(struct kvm *kvm, pgd_t *pgd,
341                              phys_addr_t addr, phys_addr_t end)
342{
343        pud_t *pud;
344        phys_addr_t next;
345
346        pud = stage2_pud_offset(pgd, addr);
347        do {
348                next = stage2_pud_addr_end(addr, end);
349                if (!stage2_pud_none(*pud)) {
350                        if (stage2_pud_huge(*pud))
351                                kvm_flush_dcache_pud(*pud);
352                        else
353                                stage2_flush_pmds(kvm, pud, addr, next);
354                }
355        } while (pud++, addr = next, addr != end);
356}
357
358static void stage2_flush_memslot(struct kvm *kvm,
359                                 struct kvm_memory_slot *memslot)
360{
361        phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
362        phys_addr_t end = addr + PAGE_SIZE * memslot->npages;
363        phys_addr_t next;
364        pgd_t *pgd;
365
366        pgd = kvm->arch.pgd + stage2_pgd_index(addr);
367        do {
368                next = stage2_pgd_addr_end(addr, end);
369                stage2_flush_puds(kvm, pgd, addr, next);
370        } while (pgd++, addr = next, addr != end);
371}
372
373/**
374 * stage2_flush_vm - Invalidate cache for pages mapped in stage 2
375 * @kvm: The struct kvm pointer
376 *
377 * Go through the stage 2 page tables and invalidate any cache lines
378 * backing memory already mapped to the VM.
379 */
380static void stage2_flush_vm(struct kvm *kvm)
381{
382        struct kvm_memslots *slots;
383        struct kvm_memory_slot *memslot;
384        int idx;
385
386        idx = srcu_read_lock(&kvm->srcu);
387        spin_lock(&kvm->mmu_lock);
388
389        slots = kvm_memslots(kvm);
390        kvm_for_each_memslot(memslot, slots)
391                stage2_flush_memslot(kvm, memslot);
392
393        spin_unlock(&kvm->mmu_lock);
394        srcu_read_unlock(&kvm->srcu, idx);
395}
396
397static void clear_hyp_pgd_entry(pgd_t *pgd)
398{
399        pud_t *pud_table __maybe_unused = pud_offset(pgd, 0UL);
400        pgd_clear(pgd);
401        pud_free(NULL, pud_table);
402        put_page(virt_to_page(pgd));
403}
404
405static void clear_hyp_pud_entry(pud_t *pud)
406{
407        pmd_t *pmd_table __maybe_unused = pmd_offset(pud, 0);
408        VM_BUG_ON(pud_huge(*pud));
409        pud_clear(pud);
410        pmd_free(NULL, pmd_table);
411        put_page(virt_to_page(pud));
412}
413
414static void clear_hyp_pmd_entry(pmd_t *pmd)
415{
416        pte_t *pte_table = pte_offset_kernel(pmd, 0);
417        VM_BUG_ON(pmd_thp_or_huge(*pmd));
418        pmd_clear(pmd);
419        pte_free_kernel(NULL, pte_table);
420        put_page(virt_to_page(pmd));
421}
422
423static void unmap_hyp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end)
424{
425        pte_t *pte, *start_pte;
426
427        start_pte = pte = pte_offset_kernel(pmd, addr);
428        do {
429                if (!pte_none(*pte)) {
430                        kvm_set_pte(pte, __pte(0));
431                        put_page(virt_to_page(pte));
432                }
433        } while (pte++, addr += PAGE_SIZE, addr != end);
434
435        if (hyp_pte_table_empty(start_pte))
436                clear_hyp_pmd_entry(pmd);
437}
438
439static void unmap_hyp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end)
440{
441        phys_addr_t next;
442        pmd_t *pmd, *start_pmd;
443
444        start_pmd = pmd = pmd_offset(pud, addr);
445        do {
446                next = pmd_addr_end(addr, end);
447                /* Hyp doesn't use huge pmds */
448                if (!pmd_none(*pmd))
449                        unmap_hyp_ptes(pmd, addr, next);
450        } while (pmd++, addr = next, addr != end);
451
452        if (hyp_pmd_table_empty(start_pmd))
453                clear_hyp_pud_entry(pud);
454}
455
456static void unmap_hyp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end)
457{
458        phys_addr_t next;
459        pud_t *pud, *start_pud;
460
461        start_pud = pud = pud_offset(pgd, addr);
462        do {
463                next = pud_addr_end(addr, end);
464                /* Hyp doesn't use huge puds */
465                if (!pud_none(*pud))
466                        unmap_hyp_pmds(pud, addr, next);
467        } while (pud++, addr = next, addr != end);
468
469        if (hyp_pud_table_empty(start_pud))
470                clear_hyp_pgd_entry(pgd);
471}
472
473static void unmap_hyp_range(pgd_t *pgdp, phys_addr_t start, u64 size)
474{
475        pgd_t *pgd;
476        phys_addr_t addr = start, end = start + size;
477        phys_addr_t next;
478
479        /*
480         * We don't unmap anything from HYP, except at the hyp tear down.
481         * Hence, we don't have to invalidate the TLBs here.
482         */
483        pgd = pgdp + pgd_index(addr);
484        do {
485                next = pgd_addr_end(addr, end);
486                if (!pgd_none(*pgd))
487                        unmap_hyp_puds(pgd, addr, next);
488        } while (pgd++, addr = next, addr != end);
489}
490
491/**
492 * free_hyp_pgds - free Hyp-mode page tables
493 *
494 * Assumes hyp_pgd is a page table used strictly in Hyp-mode and
495 * therefore contains either mappings in the kernel memory area (above
496 * PAGE_OFFSET), or device mappings in the vmalloc range (from
497 * VMALLOC_START to VMALLOC_END).
498 *
499 * boot_hyp_pgd should only map two pages for the init code.
500 */
501void free_hyp_pgds(void)
502{
503        unsigned long addr;
504
505        mutex_lock(&kvm_hyp_pgd_mutex);
506
507        if (boot_hyp_pgd) {
508                unmap_hyp_range(boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE);
509                free_pages((unsigned long)boot_hyp_pgd, hyp_pgd_order);
510                boot_hyp_pgd = NULL;
511        }
512
513        if (hyp_pgd) {
514                unmap_hyp_range(hyp_pgd, hyp_idmap_start, PAGE_SIZE);
515                for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE)
516                        unmap_hyp_range(hyp_pgd, kern_hyp_va(addr), PGDIR_SIZE);
517                for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE)
518                        unmap_hyp_range(hyp_pgd, kern_hyp_va(addr), PGDIR_SIZE);
519
520                free_pages((unsigned long)hyp_pgd, hyp_pgd_order);
521                hyp_pgd = NULL;
522        }
523        if (merged_hyp_pgd) {
524                clear_page(merged_hyp_pgd);
525                free_page((unsigned long)merged_hyp_pgd);
526                merged_hyp_pgd = NULL;
527        }
528
529        mutex_unlock(&kvm_hyp_pgd_mutex);
530}
531
532static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start,
533                                    unsigned long end, unsigned long pfn,
534                                    pgprot_t prot)
535{
536        pte_t *pte;
537        unsigned long addr;
538
539        addr = start;
540        do {
541                pte = pte_offset_kernel(pmd, addr);
542                kvm_set_pte(pte, pfn_pte(pfn, prot));
543                get_page(virt_to_page(pte));
544                kvm_flush_dcache_to_poc(pte, sizeof(*pte));
545                pfn++;
546        } while (addr += PAGE_SIZE, addr != end);
547}
548
549static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start,
550                                   unsigned long end, unsigned long pfn,
551                                   pgprot_t prot)
552{
553        pmd_t *pmd;
554        pte_t *pte;
555        unsigned long addr, next;
556
557        addr = start;
558        do {
559                pmd = pmd_offset(pud, addr);
560
561                BUG_ON(pmd_sect(*pmd));
562
563                if (pmd_none(*pmd)) {
564                        pte = pte_alloc_one_kernel(NULL, addr);
565                        if (!pte) {
566                                kvm_err("Cannot allocate Hyp pte\n");
567                                return -ENOMEM;
568                        }
569                        pmd_populate_kernel(NULL, pmd, pte);
570                        get_page(virt_to_page(pmd));
571                        kvm_flush_dcache_to_poc(pmd, sizeof(*pmd));
572                }
573
574                next = pmd_addr_end(addr, end);
575
576                create_hyp_pte_mappings(pmd, addr, next, pfn, prot);
577                pfn += (next - addr) >> PAGE_SHIFT;
578        } while (addr = next, addr != end);
579
580        return 0;
581}
582
583static int create_hyp_pud_mappings(pgd_t *pgd, unsigned long start,
584                                   unsigned long end, unsigned long pfn,
585                                   pgprot_t prot)
586{
587        pud_t *pud;
588        pmd_t *pmd;
589        unsigned long addr, next;
590        int ret;
591
592        addr = start;
593        do {
594                pud = pud_offset(pgd, addr);
595
596                if (pud_none_or_clear_bad(pud)) {
597                        pmd = pmd_alloc_one(NULL, addr);
598                        if (!pmd) {
599                                kvm_err("Cannot allocate Hyp pmd\n");
600                                return -ENOMEM;
601                        }
602                        pud_populate(NULL, pud, pmd);
603                        get_page(virt_to_page(pud));
604                        kvm_flush_dcache_to_poc(pud, sizeof(*pud));
605                }
606
607                next = pud_addr_end(addr, end);
608                ret = create_hyp_pmd_mappings(pud, addr, next, pfn, prot);
609                if (ret)
610                        return ret;
611                pfn += (next - addr) >> PAGE_SHIFT;
612        } while (addr = next, addr != end);
613
614        return 0;
615}
616
617static int __create_hyp_mappings(pgd_t *pgdp,
618                                 unsigned long start, unsigned long end,
619                                 unsigned long pfn, pgprot_t prot)
620{
621        pgd_t *pgd;
622        pud_t *pud;
623        unsigned long addr, next;
624        int err = 0;
625
626        mutex_lock(&kvm_hyp_pgd_mutex);
627        addr = start & PAGE_MASK;
628        end = PAGE_ALIGN(end);
629        do {
630                pgd = pgdp + pgd_index(addr);
631
632                if (pgd_none(*pgd)) {
633                        pud = pud_alloc_one(NULL, addr);
634                        if (!pud) {
635                                kvm_err("Cannot allocate Hyp pud\n");
636                                err = -ENOMEM;
637                                goto out;
638                        }
639                        pgd_populate(NULL, pgd, pud);
640                        get_page(virt_to_page(pgd));
641                        kvm_flush_dcache_to_poc(pgd, sizeof(*pgd));
642                }
643
644                next = pgd_addr_end(addr, end);
645                err = create_hyp_pud_mappings(pgd, addr, next, pfn, prot);
646                if (err)
647                        goto out;
648                pfn += (next - addr) >> PAGE_SHIFT;
649        } while (addr = next, addr != end);
650out:
651        mutex_unlock(&kvm_hyp_pgd_mutex);
652        return err;
653}
654
655static phys_addr_t kvm_kaddr_to_phys(void *kaddr)
656{
657        if (!is_vmalloc_addr(kaddr)) {
658                BUG_ON(!virt_addr_valid(kaddr));
659                return __pa(kaddr);
660        } else {
661                return page_to_phys(vmalloc_to_page(kaddr)) +
662                       offset_in_page(kaddr);
663        }
664}
665
666/**
667 * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode
668 * @from:       The virtual kernel start address of the range
669 * @to:         The virtual kernel end address of the range (exclusive)
670 * @prot:       The protection to be applied to this range
671 *
672 * The same virtual address as the kernel virtual address is also used
673 * in Hyp-mode mapping (modulo HYP_PAGE_OFFSET) to the same underlying
674 * physical pages.
675 */
676int create_hyp_mappings(void *from, void *to, pgprot_t prot)
677{
678        phys_addr_t phys_addr;
679        unsigned long virt_addr;
680        unsigned long start = kern_hyp_va((unsigned long)from);
681        unsigned long end = kern_hyp_va((unsigned long)to);
682
683        if (is_kernel_in_hyp_mode())
684                return 0;
685
686        start = start & PAGE_MASK;
687        end = PAGE_ALIGN(end);
688
689        for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) {
690                int err;
691
692                phys_addr = kvm_kaddr_to_phys(from + virt_addr - start);
693                err = __create_hyp_mappings(hyp_pgd, virt_addr,
694                                            virt_addr + PAGE_SIZE,
695                                            __phys_to_pfn(phys_addr),
696                                            prot);
697                if (err)
698                        return err;
699        }
700
701        return 0;
702}
703
704/**
705 * create_hyp_io_mappings - duplicate a kernel IO mapping into Hyp mode
706 * @from:       The kernel start VA of the range
707 * @to:         The kernel end VA of the range (exclusive)
708 * @phys_addr:  The physical start address which gets mapped
709 *
710 * The resulting HYP VA is the same as the kernel VA, modulo
711 * HYP_PAGE_OFFSET.
712 */
713int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_addr)
714{
715        unsigned long start = kern_hyp_va((unsigned long)from);
716        unsigned long end = kern_hyp_va((unsigned long)to);
717
718        if (is_kernel_in_hyp_mode())
719                return 0;
720
721        /* Check for a valid kernel IO mapping */
722        if (!is_vmalloc_addr(from) || !is_vmalloc_addr(to - 1))
723                return -EINVAL;
724
725        return __create_hyp_mappings(hyp_pgd, start, end,
726                                     __phys_to_pfn(phys_addr), PAGE_HYP_DEVICE);
727}
728
729/**
730 * kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation.
731 * @kvm:        The KVM struct pointer for the VM.
732 *
733 * Allocates only the stage-2 HW PGD level table(s) (can support either full
734 * 40-bit input addresses or limited to 32-bit input addresses). Clears the
735 * allocated pages.
736 *
737 * Note we don't need locking here as this is only called when the VM is
738 * created, which can only be done once.
739 */
740int kvm_alloc_stage2_pgd(struct kvm *kvm)
741{
742        pgd_t *pgd;
743
744        if (kvm->arch.pgd != NULL) {
745                kvm_err("kvm_arch already initialized?\n");
746                return -EINVAL;
747        }
748
749        /* Allocate the HW PGD, making sure that each page gets its own refcount */
750        pgd = alloc_pages_exact(S2_PGD_SIZE, GFP_KERNEL | __GFP_ZERO);
751        if (!pgd)
752                return -ENOMEM;
753
754        kvm->arch.pgd = pgd;
755        return 0;
756}
757
758static void stage2_unmap_memslot(struct kvm *kvm,
759                                 struct kvm_memory_slot *memslot)
760{
761        hva_t hva = memslot->userspace_addr;
762        phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
763        phys_addr_t size = PAGE_SIZE * memslot->npages;
764        hva_t reg_end = hva + size;
765
766        /*
767         * A memory region could potentially cover multiple VMAs, and any holes
768         * between them, so iterate over all of them to find out if we should
769         * unmap any of them.
770         *
771         *     +--------------------------------------------+
772         * +---------------+----------------+   +----------------+
773         * |   : VMA 1     |      VMA 2     |   |    VMA 3  :    |
774         * +---------------+----------------+   +----------------+
775         *     |               memory region                |
776         *     +--------------------------------------------+
777         */
778        do {
779                struct vm_area_struct *vma = find_vma(current->mm, hva);
780                hva_t vm_start, vm_end;
781
782                if (!vma || vma->vm_start >= reg_end)
783                        break;
784
785                /*
786                 * Take the intersection of this VMA with the memory region
787                 */
788                vm_start = max(hva, vma->vm_start);
789                vm_end = min(reg_end, vma->vm_end);
790
791                if (!(vma->vm_flags & VM_PFNMAP)) {
792                        gpa_t gpa = addr + (vm_start - memslot->userspace_addr);
793                        unmap_stage2_range(kvm, gpa, vm_end - vm_start);
794                }
795                hva = vm_end;
796        } while (hva < reg_end);
797}
798
799/**
800 * stage2_unmap_vm - Unmap Stage-2 RAM mappings
801 * @kvm: The struct kvm pointer
802 *
803 * Go through the memregions and unmap any reguler RAM
804 * backing memory already mapped to the VM.
805 */
806void stage2_unmap_vm(struct kvm *kvm)
807{
808        struct kvm_memslots *slots;
809        struct kvm_memory_slot *memslot;
810        int idx;
811
812        idx = srcu_read_lock(&kvm->srcu);
813        down_read(&current->mm->mmap_sem);
814        spin_lock(&kvm->mmu_lock);
815
816        slots = kvm_memslots(kvm);
817        kvm_for_each_memslot(memslot, slots)
818                stage2_unmap_memslot(kvm, memslot);
819
820        spin_unlock(&kvm->mmu_lock);
821        up_read(&current->mm->mmap_sem);
822        srcu_read_unlock(&kvm->srcu, idx);
823}
824
825/**
826 * kvm_free_stage2_pgd - free all stage-2 tables
827 * @kvm:        The KVM struct pointer for the VM.
828 *
829 * Walks the level-1 page table pointed to by kvm->arch.pgd and frees all
830 * underlying level-2 and level-3 tables before freeing the actual level-1 table
831 * and setting the struct pointer to NULL.
832 *
833 * Note we don't need locking here as this is only called when the VM is
834 * destroyed, which can only be done once.
835 */
836void kvm_free_stage2_pgd(struct kvm *kvm)
837{
838        if (kvm->arch.pgd == NULL)
839                return;
840
841        spin_lock(&kvm->mmu_lock);
842        unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE);
843        spin_unlock(&kvm->mmu_lock);
844
845        /* Free the HW pgd, one page at a time */
846        free_pages_exact(kvm->arch.pgd, S2_PGD_SIZE);
847        kvm->arch.pgd = NULL;
848}
849
850static pud_t *stage2_get_pud(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
851                             phys_addr_t addr)
852{
853        pgd_t *pgd;
854        pud_t *pud;
855
856        pgd = kvm->arch.pgd + stage2_pgd_index(addr);
857        if (WARN_ON(stage2_pgd_none(*pgd))) {
858                if (!cache)
859                        return NULL;
860                pud = mmu_memory_cache_alloc(cache);
861                stage2_pgd_populate(pgd, pud);
862                get_page(virt_to_page(pgd));
863        }
864
865        return stage2_pud_offset(pgd, addr);
866}
867
868static pmd_t *stage2_get_pmd(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
869                             phys_addr_t addr)
870{
871        pud_t *pud;
872        pmd_t *pmd;
873
874        pud = stage2_get_pud(kvm, cache, addr);
875        if (stage2_pud_none(*pud)) {
876                if (!cache)
877                        return NULL;
878                pmd = mmu_memory_cache_alloc(cache);
879                stage2_pud_populate(pud, pmd);
880                get_page(virt_to_page(pud));
881        }
882
883        return stage2_pmd_offset(pud, addr);
884}
885
886static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache
887                               *cache, phys_addr_t addr, const pmd_t *new_pmd)
888{
889        pmd_t *pmd, old_pmd;
890
891        pmd = stage2_get_pmd(kvm, cache, addr);
892        VM_BUG_ON(!pmd);
893
894        /*
895         * Mapping in huge pages should only happen through a fault.  If a
896         * page is merged into a transparent huge page, the individual
897         * subpages of that huge page should be unmapped through MMU
898         * notifiers before we get here.
899         *
900         * Merging of CompoundPages is not supported; they should become
901         * splitting first, unmapped, merged, and mapped back in on-demand.
902         */
903        VM_BUG_ON(pmd_present(*pmd) && pmd_pfn(*pmd) != pmd_pfn(*new_pmd));
904
905        old_pmd = *pmd;
906        if (pmd_present(old_pmd)) {
907                pmd_clear(pmd);
908                kvm_tlb_flush_vmid_ipa(kvm, addr);
909        } else {
910                get_page(virt_to_page(pmd));
911        }
912
913        kvm_set_pmd(pmd, *new_pmd);
914        return 0;
915}
916
917static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
918                          phys_addr_t addr, const pte_t *new_pte,
919                          unsigned long flags)
920{
921        pmd_t *pmd;
922        pte_t *pte, old_pte;
923        bool iomap = flags & KVM_S2PTE_FLAG_IS_IOMAP;
924        bool logging_active = flags & KVM_S2_FLAG_LOGGING_ACTIVE;
925
926        VM_BUG_ON(logging_active && !cache);
927
928        /* Create stage-2 page table mapping - Levels 0 and 1 */
929        pmd = stage2_get_pmd(kvm, cache, addr);
930        if (!pmd) {
931                /*
932                 * Ignore calls from kvm_set_spte_hva for unallocated
933                 * address ranges.
934                 */
935                return 0;
936        }
937
938        /*
939         * While dirty page logging - dissolve huge PMD, then continue on to
940         * allocate page.
941         */
942        if (logging_active)
943                stage2_dissolve_pmd(kvm, addr, pmd);
944
945        /* Create stage-2 page mappings - Level 2 */
946        if (pmd_none(*pmd)) {
947                if (!cache)
948                        return 0; /* ignore calls from kvm_set_spte_hva */
949                pte = mmu_memory_cache_alloc(cache);
950                pmd_populate_kernel(NULL, pmd, pte);
951                get_page(virt_to_page(pmd));
952        }
953
954        pte = pte_offset_kernel(pmd, addr);
955
956        if (iomap && pte_present(*pte))
957                return -EFAULT;
958
959        /* Create 2nd stage page table mapping - Level 3 */
960        old_pte = *pte;
961        if (pte_present(old_pte)) {
962                kvm_set_pte(pte, __pte(0));
963                kvm_tlb_flush_vmid_ipa(kvm, addr);
964        } else {
965                get_page(virt_to_page(pte));
966        }
967
968        kvm_set_pte(pte, *new_pte);
969        return 0;
970}
971
972#ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
973static int stage2_ptep_test_and_clear_young(pte_t *pte)
974{
975        if (pte_young(*pte)) {
976                *pte = pte_mkold(*pte);
977                return 1;
978        }
979        return 0;
980}
981#else
982static int stage2_ptep_test_and_clear_young(pte_t *pte)
983{
984        return __ptep_test_and_clear_young(pte);
985}
986#endif
987
988static int stage2_pmdp_test_and_clear_young(pmd_t *pmd)
989{
990        return stage2_ptep_test_and_clear_young((pte_t *)pmd);
991}
992
993/**
994 * kvm_phys_addr_ioremap - map a device range to guest IPA
995 *
996 * @kvm:        The KVM pointer
997 * @guest_ipa:  The IPA at which to insert the mapping
998 * @pa:         The physical address of the device
999 * @size:       The size of the mapping
1000 */
1001int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
1002                          phys_addr_t pa, unsigned long size, bool writable)
1003{
1004        phys_addr_t addr, end;
1005        int ret = 0;
1006        unsigned long pfn;
1007        struct kvm_mmu_memory_cache cache = { 0, };
1008
1009        end = (guest_ipa + size + PAGE_SIZE - 1) & PAGE_MASK;
1010        pfn = __phys_to_pfn(pa);
1011
1012        for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) {
1013                pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE);
1014
1015                if (writable)
1016                        pte = kvm_s2pte_mkwrite(pte);
1017
1018                ret = mmu_topup_memory_cache(&cache, KVM_MMU_CACHE_MIN_PAGES,
1019                                                KVM_NR_MEM_OBJS);
1020                if (ret)
1021                        goto out;
1022                spin_lock(&kvm->mmu_lock);
1023                ret = stage2_set_pte(kvm, &cache, addr, &pte,
1024                                                KVM_S2PTE_FLAG_IS_IOMAP);
1025                spin_unlock(&kvm->mmu_lock);
1026                if (ret)
1027                        goto out;
1028
1029                pfn++;
1030        }
1031
1032out:
1033        mmu_free_memory_cache(&cache);
1034        return ret;
1035}
1036
1037static bool transparent_hugepage_adjust(kvm_pfn_t *pfnp, phys_addr_t *ipap)
1038{
1039        kvm_pfn_t pfn = *pfnp;
1040        gfn_t gfn = *ipap >> PAGE_SHIFT;
1041
1042        if (PageTransCompoundMap(pfn_to_page(pfn))) {
1043                unsigned long mask;
1044                /*
1045                 * The address we faulted on is backed by a transparent huge
1046                 * page.  However, because we map the compound huge page and
1047                 * not the individual tail page, we need to transfer the
1048                 * refcount to the head page.  We have to be careful that the
1049                 * THP doesn't start to split while we are adjusting the
1050                 * refcounts.
1051                 *
1052                 * We are sure this doesn't happen, because mmu_notifier_retry
1053                 * was successful and we are holding the mmu_lock, so if this
1054                 * THP is trying to split, it will be blocked in the mmu
1055                 * notifier before touching any of the pages, specifically
1056                 * before being able to call __split_huge_page_refcount().
1057                 *
1058                 * We can therefore safely transfer the refcount from PG_tail
1059                 * to PG_head and switch the pfn from a tail page to the head
1060                 * page accordingly.
1061                 */
1062                mask = PTRS_PER_PMD - 1;
1063                VM_BUG_ON((gfn & mask) != (pfn & mask));
1064                if (pfn & mask) {
1065                        *ipap &= PMD_MASK;
1066                        kvm_release_pfn_clean(pfn);
1067                        pfn &= ~mask;
1068                        kvm_get_pfn(pfn);
1069                        *pfnp = pfn;
1070                }
1071
1072                return true;
1073        }
1074
1075        return false;
1076}
1077
1078static bool kvm_is_write_fault(struct kvm_vcpu *vcpu)
1079{
1080        if (kvm_vcpu_trap_is_iabt(vcpu))
1081                return false;
1082
1083        return kvm_vcpu_dabt_iswrite(vcpu);
1084}
1085
1086/**
1087 * stage2_wp_ptes - write protect PMD range
1088 * @pmd:        pointer to pmd entry
1089 * @addr:       range start address
1090 * @end:        range end address
1091 */
1092static void stage2_wp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end)
1093{
1094        pte_t *pte;
1095
1096        pte = pte_offset_kernel(pmd, addr);
1097        do {
1098                if (!pte_none(*pte)) {
1099                        if (!kvm_s2pte_readonly(pte))
1100                                kvm_set_s2pte_readonly(pte);
1101                }
1102        } while (pte++, addr += PAGE_SIZE, addr != end);
1103}
1104
1105/**
1106 * stage2_wp_pmds - write protect PUD range
1107 * @pud:        pointer to pud entry
1108 * @addr:       range start address
1109 * @end:        range end address
1110 */
1111static void stage2_wp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end)
1112{
1113        pmd_t *pmd;
1114        phys_addr_t next;
1115
1116        pmd = stage2_pmd_offset(pud, addr);
1117
1118        do {
1119                next = stage2_pmd_addr_end(addr, end);
1120                if (!pmd_none(*pmd)) {
1121                        if (pmd_thp_or_huge(*pmd)) {
1122                                if (!kvm_s2pmd_readonly(pmd))
1123                                        kvm_set_s2pmd_readonly(pmd);
1124                        } else {
1125                                stage2_wp_ptes(pmd, addr, next);
1126                        }
1127                }
1128        } while (pmd++, addr = next, addr != end);
1129}
1130
1131/**
1132  * stage2_wp_puds - write protect PGD range
1133  * @pgd:       pointer to pgd entry
1134  * @addr:      range start address
1135  * @end:       range end address
1136  *
1137  * Process PUD entries, for a huge PUD we cause a panic.
1138  */
1139static void  stage2_wp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end)
1140{
1141        pud_t *pud;
1142        phys_addr_t next;
1143
1144        pud = stage2_pud_offset(pgd, addr);
1145        do {
1146                next = stage2_pud_addr_end(addr, end);
1147                if (!stage2_pud_none(*pud)) {
1148                        /* TODO:PUD not supported, revisit later if supported */
1149                        BUG_ON(stage2_pud_huge(*pud));
1150                        stage2_wp_pmds(pud, addr, next);
1151                }
1152        } while (pud++, addr = next, addr != end);
1153}
1154
1155/**
1156 * stage2_wp_range() - write protect stage2 memory region range
1157 * @kvm:        The KVM pointer
1158 * @addr:       Start address of range
1159 * @end:        End address of range
1160 */
1161static void stage2_wp_range(struct kvm *kvm, phys_addr_t addr, phys_addr_t end)
1162{
1163        pgd_t *pgd;
1164        phys_addr_t next;
1165
1166        pgd = kvm->arch.pgd + stage2_pgd_index(addr);
1167        do {
1168                /*
1169                 * Release kvm_mmu_lock periodically if the memory region is
1170                 * large. Otherwise, we may see kernel panics with
1171                 * CONFIG_DETECT_HUNG_TASK, CONFIG_LOCKUP_DETECTOR,
1172                 * CONFIG_LOCKDEP. Additionally, holding the lock too long
1173                 * will also starve other vCPUs.
1174                 */
1175                if (need_resched() || spin_needbreak(&kvm->mmu_lock))
1176                        cond_resched_lock(&kvm->mmu_lock);
1177
1178                next = stage2_pgd_addr_end(addr, end);
1179                if (stage2_pgd_present(*pgd))
1180                        stage2_wp_puds(pgd, addr, next);
1181        } while (pgd++, addr = next, addr != end);
1182}
1183
1184/**
1185 * kvm_mmu_wp_memory_region() - write protect stage 2 entries for memory slot
1186 * @kvm:        The KVM pointer
1187 * @slot:       The memory slot to write protect
1188 *
1189 * Called to start logging dirty pages after memory region
1190 * KVM_MEM_LOG_DIRTY_PAGES operation is called. After this function returns
1191 * all present PMD and PTEs are write protected in the memory region.
1192 * Afterwards read of dirty page log can be called.
1193 *
1194 * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired,
1195 * serializing operations for VM memory regions.
1196 */
1197void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot)
1198{
1199        struct kvm_memslots *slots = kvm_memslots(kvm);
1200        struct kvm_memory_slot *memslot = id_to_memslot(slots, slot);
1201        phys_addr_t start = memslot->base_gfn << PAGE_SHIFT;
1202        phys_addr_t end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT;
1203
1204        spin_lock(&kvm->mmu_lock);
1205        stage2_wp_range(kvm, start, end);
1206        spin_unlock(&kvm->mmu_lock);
1207        kvm_flush_remote_tlbs(kvm);
1208}
1209
1210/**
1211 * kvm_mmu_write_protect_pt_masked() - write protect dirty pages
1212 * @kvm:        The KVM pointer
1213 * @slot:       The memory slot associated with mask
1214 * @gfn_offset: The gfn offset in memory slot
1215 * @mask:       The mask of dirty pages at offset 'gfn_offset' in this memory
1216 *              slot to be write protected
1217 *
1218 * Walks bits set in mask write protects the associated pte's. Caller must
1219 * acquire kvm_mmu_lock.
1220 */
1221static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm,
1222                struct kvm_memory_slot *slot,
1223                gfn_t gfn_offset, unsigned long mask)
1224{
1225        phys_addr_t base_gfn = slot->base_gfn + gfn_offset;
1226        phys_addr_t start = (base_gfn +  __ffs(mask)) << PAGE_SHIFT;
1227        phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT;
1228
1229        stage2_wp_range(kvm, start, end);
1230}
1231
1232/*
1233 * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected
1234 * dirty pages.
1235 *
1236 * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to
1237 * enable dirty logging for them.
1238 */
1239void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
1240                struct kvm_memory_slot *slot,
1241                gfn_t gfn_offset, unsigned long mask)
1242{
1243        kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
1244}
1245
1246static void coherent_cache_guest_page(struct kvm_vcpu *vcpu, kvm_pfn_t pfn,
1247                                      unsigned long size, bool uncached)
1248{
1249        __coherent_cache_guest_page(vcpu, pfn, size, uncached);
1250}
1251
1252static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
1253                          struct kvm_memory_slot *memslot, unsigned long hva,
1254                          unsigned long fault_status)
1255{
1256        int ret;
1257        bool write_fault, writable, hugetlb = false, force_pte = false;
1258        unsigned long mmu_seq;
1259        gfn_t gfn = fault_ipa >> PAGE_SHIFT;
1260        struct kvm *kvm = vcpu->kvm;
1261        struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
1262        struct vm_area_struct *vma;
1263        kvm_pfn_t pfn;
1264        pgprot_t mem_type = PAGE_S2;
1265        bool fault_ipa_uncached;
1266        bool logging_active = memslot_is_logging(memslot);
1267        unsigned long flags = 0;
1268
1269        write_fault = kvm_is_write_fault(vcpu);
1270        if (fault_status == FSC_PERM && !write_fault) {
1271                kvm_err("Unexpected L2 read permission error\n");
1272                return -EFAULT;
1273        }
1274
1275        /* Let's check if we will get back a huge page backed by hugetlbfs */
1276        down_read(&current->mm->mmap_sem);
1277        vma = find_vma_intersection(current->mm, hva, hva + 1);
1278        if (unlikely(!vma)) {
1279                kvm_err("Failed to find VMA for hva 0x%lx\n", hva);
1280                up_read(&current->mm->mmap_sem);
1281                return -EFAULT;
1282        }
1283
1284        if (is_vm_hugetlb_page(vma) && !logging_active) {
1285                hugetlb = true;
1286                gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT;
1287        } else {
1288                /*
1289                 * Pages belonging to memslots that don't have the same
1290                 * alignment for userspace and IPA cannot be mapped using
1291                 * block descriptors even if the pages belong to a THP for
1292                 * the process, because the stage-2 block descriptor will
1293                 * cover more than a single THP and we loose atomicity for
1294                 * unmapping, updates, and splits of the THP or other pages
1295                 * in the stage-2 block range.
1296                 */
1297                if ((memslot->userspace_addr & ~PMD_MASK) !=
1298                    ((memslot->base_gfn << PAGE_SHIFT) & ~PMD_MASK))
1299                        force_pte = true;
1300        }
1301        up_read(&current->mm->mmap_sem);
1302
1303        /* We need minimum second+third level pages */
1304        ret = mmu_topup_memory_cache(memcache, KVM_MMU_CACHE_MIN_PAGES,
1305                                     KVM_NR_MEM_OBJS);
1306        if (ret)
1307                return ret;
1308
1309        mmu_seq = vcpu->kvm->mmu_notifier_seq;
1310        /*
1311         * Ensure the read of mmu_notifier_seq happens before we call
1312         * gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk
1313         * the page we just got a reference to gets unmapped before we have a
1314         * chance to grab the mmu_lock, which ensure that if the page gets
1315         * unmapped afterwards, the call to kvm_unmap_hva will take it away
1316         * from us again properly. This smp_rmb() interacts with the smp_wmb()
1317         * in kvm_mmu_notifier_invalidate_<page|range_end>.
1318         */
1319        smp_rmb();
1320
1321        pfn = gfn_to_pfn_prot(kvm, gfn, write_fault, &writable);
1322        if (is_error_noslot_pfn(pfn))
1323                return -EFAULT;
1324
1325        if (kvm_is_device_pfn(pfn)) {
1326                mem_type = PAGE_S2_DEVICE;
1327                flags |= KVM_S2PTE_FLAG_IS_IOMAP;
1328        } else if (logging_active) {
1329                /*
1330                 * Faults on pages in a memslot with logging enabled
1331                 * should not be mapped with huge pages (it introduces churn
1332                 * and performance degradation), so force a pte mapping.
1333                 */
1334                force_pte = true;
1335                flags |= KVM_S2_FLAG_LOGGING_ACTIVE;
1336
1337                /*
1338                 * Only actually map the page as writable if this was a write
1339                 * fault.
1340                 */
1341                if (!write_fault)
1342                        writable = false;
1343        }
1344
1345        spin_lock(&kvm->mmu_lock);
1346        if (mmu_notifier_retry(kvm, mmu_seq))
1347                goto out_unlock;
1348
1349        if (!hugetlb && !force_pte)
1350                hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa);
1351
1352        fault_ipa_uncached = memslot->flags & KVM_MEMSLOT_INCOHERENT;
1353
1354        if (hugetlb) {
1355                pmd_t new_pmd = pfn_pmd(pfn, mem_type);
1356                new_pmd = pmd_mkhuge(new_pmd);
1357                if (writable) {
1358                        new_pmd = kvm_s2pmd_mkwrite(new_pmd);
1359                        kvm_set_pfn_dirty(pfn);
1360                }
1361                coherent_cache_guest_page(vcpu, pfn, PMD_SIZE, fault_ipa_uncached);
1362                ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd);
1363        } else {
1364                pte_t new_pte = pfn_pte(pfn, mem_type);
1365
1366                if (writable) {
1367                        new_pte = kvm_s2pte_mkwrite(new_pte);
1368                        kvm_set_pfn_dirty(pfn);
1369                        mark_page_dirty(kvm, gfn);
1370                }
1371                coherent_cache_guest_page(vcpu, pfn, PAGE_SIZE, fault_ipa_uncached);
1372                ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, flags);
1373        }
1374
1375out_unlock:
1376        spin_unlock(&kvm->mmu_lock);
1377        kvm_set_pfn_accessed(pfn);
1378        kvm_release_pfn_clean(pfn);
1379        return ret;
1380}
1381
1382/*
1383 * Resolve the access fault by making the page young again.
1384 * Note that because the faulting entry is guaranteed not to be
1385 * cached in the TLB, we don't need to invalidate anything.
1386 * Only the HW Access Flag updates are supported for Stage 2 (no DBM),
1387 * so there is no need for atomic (pte|pmd)_mkyoung operations.
1388 */
1389static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
1390{
1391        pmd_t *pmd;
1392        pte_t *pte;
1393        kvm_pfn_t pfn;
1394        bool pfn_valid = false;
1395
1396        trace_kvm_access_fault(fault_ipa);
1397
1398        spin_lock(&vcpu->kvm->mmu_lock);
1399
1400        pmd = stage2_get_pmd(vcpu->kvm, NULL, fault_ipa);
1401        if (!pmd || pmd_none(*pmd))     /* Nothing there */
1402                goto out;
1403
1404        if (pmd_thp_or_huge(*pmd)) {    /* THP, HugeTLB */
1405                *pmd = pmd_mkyoung(*pmd);
1406                pfn = pmd_pfn(*pmd);
1407                pfn_valid = true;
1408                goto out;
1409        }
1410
1411        pte = pte_offset_kernel(pmd, fault_ipa);
1412        if (pte_none(*pte))             /* Nothing there either */
1413                goto out;
1414
1415        *pte = pte_mkyoung(*pte);       /* Just a page... */
1416        pfn = pte_pfn(*pte);
1417        pfn_valid = true;
1418out:
1419        spin_unlock(&vcpu->kvm->mmu_lock);
1420        if (pfn_valid)
1421                kvm_set_pfn_accessed(pfn);
1422}
1423
1424/**
1425 * kvm_handle_guest_abort - handles all 2nd stage aborts
1426 * @vcpu:       the VCPU pointer
1427 * @run:        the kvm_run structure
1428 *
1429 * Any abort that gets to the host is almost guaranteed to be caused by a
1430 * missing second stage translation table entry, which can mean that either the
1431 * guest simply needs more memory and we must allocate an appropriate page or it
1432 * can mean that the guest tried to access I/O memory, which is emulated by user
1433 * space. The distinction is based on the IPA causing the fault and whether this
1434 * memory region has been registered as standard RAM by user space.
1435 */
1436int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
1437{
1438        unsigned long fault_status;
1439        phys_addr_t fault_ipa;
1440        struct kvm_memory_slot *memslot;
1441        unsigned long hva;
1442        bool is_iabt, write_fault, writable;
1443        gfn_t gfn;
1444        int ret, idx;
1445
1446        is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
1447        if (unlikely(!is_iabt && kvm_vcpu_dabt_isextabt(vcpu))) {
1448                kvm_inject_vabt(vcpu);
1449                return 1;
1450        }
1451
1452        fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
1453
1454        trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_hsr(vcpu),
1455                              kvm_vcpu_get_hfar(vcpu), fault_ipa);
1456
1457        /* Check the stage-2 fault is trans. fault or write fault */
1458        fault_status = kvm_vcpu_trap_get_fault_type(vcpu);
1459        if (fault_status != FSC_FAULT && fault_status != FSC_PERM &&
1460            fault_status != FSC_ACCESS) {
1461                kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n",
1462                        kvm_vcpu_trap_get_class(vcpu),
1463                        (unsigned long)kvm_vcpu_trap_get_fault(vcpu),
1464                        (unsigned long)kvm_vcpu_get_hsr(vcpu));
1465                return -EFAULT;
1466        }
1467
1468        idx = srcu_read_lock(&vcpu->kvm->srcu);
1469
1470        gfn = fault_ipa >> PAGE_SHIFT;
1471        memslot = gfn_to_memslot(vcpu->kvm, gfn);
1472        hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
1473        write_fault = kvm_is_write_fault(vcpu);
1474        if (kvm_is_error_hva(hva) || (write_fault && !writable)) {
1475                if (is_iabt) {
1476                        /* Prefetch Abort on I/O address */
1477                        kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu));
1478                        ret = 1;
1479                        goto out_unlock;
1480                }
1481
1482                /*
1483                 * Check for a cache maintenance operation. Since we
1484                 * ended-up here, we know it is outside of any memory
1485                 * slot. But we can't find out if that is for a device,
1486                 * or if the guest is just being stupid. The only thing
1487                 * we know for sure is that this range cannot be cached.
1488                 *
1489                 * So let's assume that the guest is just being
1490                 * cautious, and skip the instruction.
1491                 */
1492                if (kvm_vcpu_dabt_is_cm(vcpu)) {
1493                        kvm_skip_instr(vcpu, kvm_vcpu_trap_il_is32bit(vcpu));
1494                        ret = 1;
1495                        goto out_unlock;
1496                }
1497
1498                /*
1499                 * The IPA is reported as [MAX:12], so we need to
1500                 * complement it with the bottom 12 bits from the
1501                 * faulting VA. This is always 12 bits, irrespective
1502                 * of the page size.
1503                 */
1504                fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ((1 << 12) - 1);
1505                ret = io_mem_abort(vcpu, run, fault_ipa);
1506                goto out_unlock;
1507        }
1508
1509        /* Userspace should not be able to register out-of-bounds IPAs */
1510        VM_BUG_ON(fault_ipa >= KVM_PHYS_SIZE);
1511
1512        if (fault_status == FSC_ACCESS) {
1513                handle_access_fault(vcpu, fault_ipa);
1514                ret = 1;
1515                goto out_unlock;
1516        }
1517
1518        ret = user_mem_abort(vcpu, fault_ipa, memslot, hva, fault_status);
1519        if (ret == 0)
1520                ret = 1;
1521out_unlock:
1522        srcu_read_unlock(&vcpu->kvm->srcu, idx);
1523        return ret;
1524}
1525
1526static int handle_hva_to_gpa(struct kvm *kvm,
1527                             unsigned long start,
1528                             unsigned long end,
1529                             int (*handler)(struct kvm *kvm,
1530                                            gpa_t gpa, void *data),
1531                             void *data)
1532{
1533        struct kvm_memslots *slots;
1534        struct kvm_memory_slot *memslot;
1535        int ret = 0;
1536
1537        slots = kvm_memslots(kvm);
1538
1539        /* we only care about the pages that the guest sees */
1540        kvm_for_each_memslot(memslot, slots) {
1541                unsigned long hva_start, hva_end;
1542                gfn_t gfn, gfn_end;
1543
1544                hva_start = max(start, memslot->userspace_addr);
1545                hva_end = min(end, memslot->userspace_addr +
1546                                        (memslot->npages << PAGE_SHIFT));
1547                if (hva_start >= hva_end)
1548                        continue;
1549
1550                /*
1551                 * {gfn(page) | page intersects with [hva_start, hva_end)} =
1552                 * {gfn_start, gfn_start+1, ..., gfn_end-1}.
1553                 */
1554                gfn = hva_to_gfn_memslot(hva_start, memslot);
1555                gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
1556
1557                for (; gfn < gfn_end; ++gfn) {
1558                        gpa_t gpa = gfn << PAGE_SHIFT;
1559                        ret |= handler(kvm, gpa, data);
1560                }
1561        }
1562
1563        return ret;
1564}
1565
1566static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, void *data)
1567{
1568        unmap_stage2_range(kvm, gpa, PAGE_SIZE);
1569        return 0;
1570}
1571
1572int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
1573{
1574        unsigned long end = hva + PAGE_SIZE;
1575
1576        if (!kvm->arch.pgd)
1577                return 0;
1578
1579        trace_kvm_unmap_hva(hva);
1580        handle_hva_to_gpa(kvm, hva, end, &kvm_unmap_hva_handler, NULL);
1581        return 0;
1582}
1583
1584int kvm_unmap_hva_range(struct kvm *kvm,
1585                        unsigned long start, unsigned long end)
1586{
1587        if (!kvm->arch.pgd)
1588                return 0;
1589
1590        trace_kvm_unmap_hva_range(start, end);
1591        handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, NULL);
1592        return 0;
1593}
1594
1595static int kvm_set_spte_handler(struct kvm *kvm, gpa_t gpa, void *data)
1596{
1597        pte_t *pte = (pte_t *)data;
1598
1599        /*
1600         * We can always call stage2_set_pte with KVM_S2PTE_FLAG_LOGGING_ACTIVE
1601         * flag clear because MMU notifiers will have unmapped a huge PMD before
1602         * calling ->change_pte() (which in turn calls kvm_set_spte_hva()) and
1603         * therefore stage2_set_pte() never needs to clear out a huge PMD
1604         * through this calling path.
1605         */
1606        stage2_set_pte(kvm, NULL, gpa, pte, 0);
1607        return 0;
1608}
1609
1610
1611void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
1612{
1613        unsigned long end = hva + PAGE_SIZE;
1614        pte_t stage2_pte;
1615
1616        if (!kvm->arch.pgd)
1617                return;
1618
1619        trace_kvm_set_spte_hva(hva);
1620        stage2_pte = pfn_pte(pte_pfn(pte), PAGE_S2);
1621        handle_hva_to_gpa(kvm, hva, end, &kvm_set_spte_handler, &stage2_pte);
1622}
1623
1624static int kvm_age_hva_handler(struct kvm *kvm, gpa_t gpa, void *data)
1625{
1626        pmd_t *pmd;
1627        pte_t *pte;
1628
1629        pmd = stage2_get_pmd(kvm, NULL, gpa);
1630        if (!pmd || pmd_none(*pmd))     /* Nothing there */
1631                return 0;
1632
1633        if (pmd_thp_or_huge(*pmd))      /* THP, HugeTLB */
1634                return stage2_pmdp_test_and_clear_young(pmd);
1635
1636        pte = pte_offset_kernel(pmd, gpa);
1637        if (pte_none(*pte))
1638                return 0;
1639
1640        return stage2_ptep_test_and_clear_young(pte);
1641}
1642
1643static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, void *data)
1644{
1645        pmd_t *pmd;
1646        pte_t *pte;
1647
1648        pmd = stage2_get_pmd(kvm, NULL, gpa);
1649        if (!pmd || pmd_none(*pmd))     /* Nothing there */
1650                return 0;
1651
1652        if (pmd_thp_or_huge(*pmd))              /* THP, HugeTLB */
1653                return pmd_young(*pmd);
1654
1655        pte = pte_offset_kernel(pmd, gpa);
1656        if (!pte_none(*pte))            /* Just a page... */
1657                return pte_young(*pte);
1658
1659        return 0;
1660}
1661
1662int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end)
1663{
1664        trace_kvm_age_hva(start, end);
1665        return handle_hva_to_gpa(kvm, start, end, kvm_age_hva_handler, NULL);
1666}
1667
1668int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
1669{
1670        trace_kvm_test_age_hva(hva);
1671        return handle_hva_to_gpa(kvm, hva, hva, kvm_test_age_hva_handler, NULL);
1672}
1673
1674void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu)
1675{
1676        mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
1677}
1678
1679phys_addr_t kvm_mmu_get_httbr(void)
1680{
1681        if (__kvm_cpu_uses_extended_idmap())
1682                return virt_to_phys(merged_hyp_pgd);
1683        else
1684                return virt_to_phys(hyp_pgd);
1685}
1686
1687phys_addr_t kvm_get_idmap_vector(void)
1688{
1689        return hyp_idmap_vector;
1690}
1691
1692phys_addr_t kvm_get_idmap_start(void)
1693{
1694        return hyp_idmap_start;
1695}
1696
1697static int kvm_map_idmap_text(pgd_t *pgd)
1698{
1699        int err;
1700
1701        /* Create the idmap in the boot page tables */
1702        err =   __create_hyp_mappings(pgd,
1703                                      hyp_idmap_start, hyp_idmap_end,
1704                                      __phys_to_pfn(hyp_idmap_start),
1705                                      PAGE_HYP_EXEC);
1706        if (err)
1707                kvm_err("Failed to idmap %lx-%lx\n",
1708                        hyp_idmap_start, hyp_idmap_end);
1709
1710        return err;
1711}
1712
1713int kvm_mmu_init(void)
1714{
1715        int err;
1716
1717        hyp_idmap_start = kvm_virt_to_phys(__hyp_idmap_text_start);
1718        hyp_idmap_end = kvm_virt_to_phys(__hyp_idmap_text_end);
1719        hyp_idmap_vector = kvm_virt_to_phys(__kvm_hyp_init);
1720
1721        /*
1722         * We rely on the linker script to ensure at build time that the HYP
1723         * init code does not cross a page boundary.
1724         */
1725        BUG_ON((hyp_idmap_start ^ (hyp_idmap_end - 1)) & PAGE_MASK);
1726
1727        kvm_info("IDMAP page: %lx\n", hyp_idmap_start);
1728        kvm_info("HYP VA range: %lx:%lx\n",
1729                 kern_hyp_va(PAGE_OFFSET), kern_hyp_va(~0UL));
1730
1731        if (hyp_idmap_start >= kern_hyp_va(PAGE_OFFSET) &&
1732            hyp_idmap_start <  kern_hyp_va(~0UL) &&
1733            hyp_idmap_start != (unsigned long)__hyp_idmap_text_start) {
1734                /*
1735                 * The idmap page is intersecting with the VA space,
1736                 * it is not safe to continue further.
1737                 */
1738                kvm_err("IDMAP intersecting with HYP VA, unable to continue\n");
1739                err = -EINVAL;
1740                goto out;
1741        }
1742
1743        hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, hyp_pgd_order);
1744        if (!hyp_pgd) {
1745                kvm_err("Hyp mode PGD not allocated\n");
1746                err = -ENOMEM;
1747                goto out;
1748        }
1749
1750        if (__kvm_cpu_uses_extended_idmap()) {
1751                boot_hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO,
1752                                                         hyp_pgd_order);
1753                if (!boot_hyp_pgd) {
1754                        kvm_err("Hyp boot PGD not allocated\n");
1755                        err = -ENOMEM;
1756                        goto out;
1757                }
1758
1759                err = kvm_map_idmap_text(boot_hyp_pgd);
1760                if (err)
1761                        goto out;
1762
1763                merged_hyp_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
1764                if (!merged_hyp_pgd) {
1765                        kvm_err("Failed to allocate extra HYP pgd\n");
1766                        goto out;
1767                }
1768                __kvm_extend_hypmap(boot_hyp_pgd, hyp_pgd, merged_hyp_pgd,
1769                                    hyp_idmap_start);
1770        } else {
1771                err = kvm_map_idmap_text(hyp_pgd);
1772                if (err)
1773                        goto out;
1774        }
1775
1776        return 0;
1777out:
1778        free_hyp_pgds();
1779        return err;
1780}
1781
1782void kvm_arch_commit_memory_region(struct kvm *kvm,
1783                                   const struct kvm_userspace_memory_region *mem,
1784                                   const struct kvm_memory_slot *old,
1785                                   const struct kvm_memory_slot *new,
1786                                   enum kvm_mr_change change)
1787{
1788        /*
1789         * At this point memslot has been committed and there is an
1790         * allocated dirty_bitmap[], dirty pages will be be tracked while the
1791         * memory slot is write protected.
1792         */
1793        if (change != KVM_MR_DELETE && mem->flags & KVM_MEM_LOG_DIRTY_PAGES)
1794                kvm_mmu_wp_memory_region(kvm, mem->slot);
1795}
1796
1797int kvm_arch_prepare_memory_region(struct kvm *kvm,
1798                                   struct kvm_memory_slot *memslot,
1799                                   const struct kvm_userspace_memory_region *mem,
1800                                   enum kvm_mr_change change)
1801{
1802        hva_t hva = mem->userspace_addr;
1803        hva_t reg_end = hva + mem->memory_size;
1804        bool writable = !(mem->flags & KVM_MEM_READONLY);
1805        int ret = 0;
1806
1807        if (change != KVM_MR_CREATE && change != KVM_MR_MOVE &&
1808                        change != KVM_MR_FLAGS_ONLY)
1809                return 0;
1810
1811        /*
1812         * Prevent userspace from creating a memory region outside of the IPA
1813         * space addressable by the KVM guest IPA space.
1814         */
1815        if (memslot->base_gfn + memslot->npages >=
1816            (KVM_PHYS_SIZE >> PAGE_SHIFT))
1817                return -EFAULT;
1818
1819        down_read(&current->mm->mmap_sem);
1820        /*
1821         * A memory region could potentially cover multiple VMAs, and any holes
1822         * between them, so iterate over all of them to find out if we can map
1823         * any of them right now.
1824         *
1825         *     +--------------------------------------------+
1826         * +---------------+----------------+   +----------------+
1827         * |   : VMA 1     |      VMA 2     |   |    VMA 3  :    |
1828         * +---------------+----------------+   +----------------+
1829         *     |               memory region                |
1830         *     +--------------------------------------------+
1831         */
1832        do {
1833                struct vm_area_struct *vma = find_vma(current->mm, hva);
1834                hva_t vm_start, vm_end;
1835
1836                if (!vma || vma->vm_start >= reg_end)
1837                        break;
1838
1839                /*
1840                 * Mapping a read-only VMA is only allowed if the
1841                 * memory region is configured as read-only.
1842                 */
1843                if (writable && !(vma->vm_flags & VM_WRITE)) {
1844                        ret = -EPERM;
1845                        break;
1846                }
1847
1848                /*
1849                 * Take the intersection of this VMA with the memory region
1850                 */
1851                vm_start = max(hva, vma->vm_start);
1852                vm_end = min(reg_end, vma->vm_end);
1853
1854                if (vma->vm_flags & VM_PFNMAP) {
1855                        gpa_t gpa = mem->guest_phys_addr +
1856                                    (vm_start - mem->userspace_addr);
1857                        phys_addr_t pa;
1858
1859                        pa = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT;
1860                        pa += vm_start - vma->vm_start;
1861
1862                        /* IO region dirty page logging not allowed */
1863                        if (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES) {
1864                                ret = -EINVAL;
1865                                goto out;
1866                        }
1867
1868                        ret = kvm_phys_addr_ioremap(kvm, gpa, pa,
1869                                                    vm_end - vm_start,
1870                                                    writable);
1871                        if (ret)
1872                                break;
1873                }
1874                hva = vm_end;
1875        } while (hva < reg_end);
1876
1877        if (change == KVM_MR_FLAGS_ONLY)
1878                goto out;
1879
1880        spin_lock(&kvm->mmu_lock);
1881        if (ret)
1882                unmap_stage2_range(kvm, mem->guest_phys_addr, mem->memory_size);
1883        else
1884                stage2_flush_memslot(kvm, memslot);
1885        spin_unlock(&kvm->mmu_lock);
1886out:
1887        up_read(&current->mm->mmap_sem);
1888        return ret;
1889}
1890
1891void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
1892                           struct kvm_memory_slot *dont)
1893{
1894}
1895
1896int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
1897                            unsigned long npages)
1898{
1899        /*
1900         * Readonly memslots are not incoherent with the caches by definition,
1901         * but in practice, they are used mostly to emulate ROMs or NOR flashes
1902         * that the guest may consider devices and hence map as uncached.
1903         * To prevent incoherency issues in these cases, tag all readonly
1904         * regions as incoherent.
1905         */
1906        if (slot->flags & KVM_MEM_READONLY)
1907                slot->flags |= KVM_MEMSLOT_INCOHERENT;
1908        return 0;
1909}
1910
1911void kvm_arch_memslots_updated(struct kvm *kvm, struct kvm_memslots *slots)
1912{
1913}
1914
1915void kvm_arch_flush_shadow_all(struct kvm *kvm)
1916{
1917        kvm_free_stage2_pgd(kvm);
1918}
1919
1920void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
1921                                   struct kvm_memory_slot *slot)
1922{
1923        gpa_t gpa = slot->base_gfn << PAGE_SHIFT;
1924        phys_addr_t size = slot->npages << PAGE_SHIFT;
1925
1926        spin_lock(&kvm->mmu_lock);
1927        unmap_stage2_range(kvm, gpa, size);
1928        spin_unlock(&kvm->mmu_lock);
1929}
1930
1931/*
1932 * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
1933 *
1934 * Main problems:
1935 * - S/W ops are local to a CPU (not broadcast)
1936 * - We have line migration behind our back (speculation)
1937 * - System caches don't support S/W at all (damn!)
1938 *
1939 * In the face of the above, the best we can do is to try and convert
1940 * S/W ops to VA ops. Because the guest is not allowed to infer the
1941 * S/W to PA mapping, it can only use S/W to nuke the whole cache,
1942 * which is a rather good thing for us.
1943 *
1944 * Also, it is only used when turning caches on/off ("The expected
1945 * usage of the cache maintenance instructions that operate by set/way
1946 * is associated with the cache maintenance instructions associated
1947 * with the powerdown and powerup of caches, if this is required by
1948 * the implementation.").
1949 *
1950 * We use the following policy:
1951 *
1952 * - If we trap a S/W operation, we enable VM trapping to detect
1953 *   caches being turned on/off, and do a full clean.
1954 *
1955 * - We flush the caches on both caches being turned on and off.
1956 *
1957 * - Once the caches are enabled, we stop trapping VM ops.
1958 */
1959void kvm_set_way_flush(struct kvm_vcpu *vcpu)
1960{
1961        unsigned long hcr = vcpu_get_hcr(vcpu);
1962
1963        /*
1964         * If this is the first time we do a S/W operation
1965         * (i.e. HCR_TVM not set) flush the whole memory, and set the
1966         * VM trapping.
1967         *
1968         * Otherwise, rely on the VM trapping to wait for the MMU +
1969         * Caches to be turned off. At that point, we'll be able to
1970         * clean the caches again.
1971         */
1972        if (!(hcr & HCR_TVM)) {
1973                trace_kvm_set_way_flush(*vcpu_pc(vcpu),
1974                                        vcpu_has_cache_enabled(vcpu));
1975                stage2_flush_vm(vcpu->kvm);
1976                vcpu_set_hcr(vcpu, hcr | HCR_TVM);
1977        }
1978}
1979
1980void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled)
1981{
1982        bool now_enabled = vcpu_has_cache_enabled(vcpu);
1983
1984        /*
1985         * If switching the MMU+caches on, need to invalidate the caches.
1986         * If switching it off, need to clean the caches.
1987         * Clean + invalidate does the trick always.
1988         */
1989        if (now_enabled != was_enabled)
1990                stage2_flush_vm(vcpu->kvm);
1991
1992        /* Caches are now on, stop trapping VM ops (until a S/W op) */
1993        if (now_enabled)
1994                vcpu_set_hcr(vcpu, vcpu_get_hcr(vcpu) & ~HCR_TVM);
1995
1996        trace_kvm_toggle_cache(*vcpu_pc(vcpu), was_enabled, now_enabled);
1997}
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