~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/arch/arm/kvm/mmu.c

Version: ~ [ linux-5.3-rc4 ] ~ [ linux-5.2.8 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.66 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.138 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.189 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.189 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.71 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  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 
 32 #include "trace.h"
 33 
 34 extern char  __hyp_idmap_text_start[], __hyp_idmap_text_end[];
 35 
 36 static pgd_t *boot_hyp_pgd;
 37 static pgd_t *hyp_pgd;
 38 static pgd_t *merged_hyp_pgd;
 39 static DEFINE_MUTEX(kvm_hyp_pgd_mutex);
 40 
 41 static unsigned long hyp_idmap_start;
 42 static unsigned long hyp_idmap_end;
 43 static phys_addr_t hyp_idmap_vector;
 44 
 45 #define hyp_pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t))
 46 
 47 #define kvm_pmd_huge(_x)        (pmd_huge(_x) || pmd_trans_huge(_x))
 48 #define kvm_pud_huge(_x)        pud_huge(_x)
 49 
 50 #define KVM_S2PTE_FLAG_IS_IOMAP         (1UL << 0)
 51 #define KVM_S2_FLAG_LOGGING_ACTIVE      (1UL << 1)
 52 
 53 static bool memslot_is_logging(struct kvm_memory_slot *memslot)
 54 {
 55         return memslot->dirty_bitmap && !(memslot->flags & KVM_MEM_READONLY);
 56 }
 57 
 58 /**
 59  * kvm_flush_remote_tlbs() - flush all VM TLB entries for v7/8
 60  * @kvm:        pointer to kvm structure.
 61  *
 62  * Interface to HYP function to flush all VM TLB entries
 63  */
 64 void kvm_flush_remote_tlbs(struct kvm *kvm)
 65 {
 66         kvm_call_hyp(__kvm_tlb_flush_vmid, kvm);
 67 }
 68 
 69 static void kvm_tlb_flush_vmid_ipa(struct kvm *kvm, phys_addr_t ipa)
 70 {
 71         /*
 72          * This function also gets called when dealing with HYP page
 73          * tables. As HYP doesn't have an associated struct kvm (and
 74          * the HYP page tables are fairly static), we don't do
 75          * anything there.
 76          */
 77         if (kvm)
 78                 kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, kvm, ipa);
 79 }
 80 
 81 /*
 82  * D-Cache management functions. They take the page table entries by
 83  * value, as they are flushing the cache using the kernel mapping (or
 84  * kmap on 32bit).
 85  */
 86 static void kvm_flush_dcache_pte(pte_t pte)
 87 {
 88         __kvm_flush_dcache_pte(pte);
 89 }
 90 
 91 static void kvm_flush_dcache_pmd(pmd_t pmd)
 92 {
 93         __kvm_flush_dcache_pmd(pmd);
 94 }
 95 
 96 static void kvm_flush_dcache_pud(pud_t pud)
 97 {
 98         __kvm_flush_dcache_pud(pud);
 99 }
100 
101 /**
102  * stage2_dissolve_pmd() - clear and flush huge PMD entry
103  * @kvm:        pointer to kvm structure.
104  * @addr:       IPA
105  * @pmd:        pmd pointer for IPA
106  *
107  * Function clears a PMD entry, flushes addr 1st and 2nd stage TLBs. Marks all
108  * pages in the range dirty.
109  */
110 static void stage2_dissolve_pmd(struct kvm *kvm, phys_addr_t addr, pmd_t *pmd)
111 {
112         if (!kvm_pmd_huge(*pmd))
113                 return;
114 
115         pmd_clear(pmd);
116         kvm_tlb_flush_vmid_ipa(kvm, addr);
117         put_page(virt_to_page(pmd));
118 }
119 
120 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache *cache,
121                                   int min, int max)
122 {
123         void *page;
124 
125         BUG_ON(max > KVM_NR_MEM_OBJS);
126         if (cache->nobjs >= min)
127                 return 0;
128         while (cache->nobjs < max) {
129                 page = (void *)__get_free_page(PGALLOC_GFP);
130                 if (!page)
131                         return -ENOMEM;
132                 cache->objects[cache->nobjs++] = page;
133         }
134         return 0;
135 }
136 
137 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache *mc)
138 {
139         while (mc->nobjs)
140                 free_page((unsigned long)mc->objects[--mc->nobjs]);
141 }
142 
143 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache *mc)
144 {
145         void *p;
146 
147         BUG_ON(!mc || !mc->nobjs);
148         p = mc->objects[--mc->nobjs];
149         return p;
150 }
151 
152 static void clear_pgd_entry(struct kvm *kvm, pgd_t *pgd, phys_addr_t addr)
153 {
154         pud_t *pud_table __maybe_unused = pud_offset(pgd, 0);
155         pgd_clear(pgd);
156         kvm_tlb_flush_vmid_ipa(kvm, addr);
157         pud_free(NULL, pud_table);
158         put_page(virt_to_page(pgd));
159 }
160 
161 static void clear_pud_entry(struct kvm *kvm, pud_t *pud, phys_addr_t addr)
162 {
163         pmd_t *pmd_table = pmd_offset(pud, 0);
164         VM_BUG_ON(pud_huge(*pud));
165         pud_clear(pud);
166         kvm_tlb_flush_vmid_ipa(kvm, addr);
167         pmd_free(NULL, pmd_table);
168         put_page(virt_to_page(pud));
169 }
170 
171 static void clear_pmd_entry(struct kvm *kvm, pmd_t *pmd, phys_addr_t addr)
172 {
173         pte_t *pte_table = pte_offset_kernel(pmd, 0);
174         VM_BUG_ON(kvm_pmd_huge(*pmd));
175         pmd_clear(pmd);
176         kvm_tlb_flush_vmid_ipa(kvm, addr);
177         pte_free_kernel(NULL, pte_table);
178         put_page(virt_to_page(pmd));
179 }
180 
181 /*
182  * Unmapping vs dcache management:
183  *
184  * If a guest maps certain memory pages as uncached, all writes will
185  * bypass the data cache and go directly to RAM.  However, the CPUs
186  * can still speculate reads (not writes) and fill cache lines with
187  * data.
188  *
189  * Those cache lines will be *clean* cache lines though, so a
190  * clean+invalidate operation is equivalent to an invalidate
191  * operation, because no cache lines are marked dirty.
192  *
193  * Those clean cache lines could be filled prior to an uncached write
194  * by the guest, and the cache coherent IO subsystem would therefore
195  * end up writing old data to disk.
196  *
197  * This is why right after unmapping a page/section and invalidating
198  * the corresponding TLBs, we call kvm_flush_dcache_p*() to make sure
199  * the IO subsystem will never hit in the cache.
200  */
201 static void unmap_ptes(struct kvm *kvm, pmd_t *pmd,
202                        phys_addr_t addr, phys_addr_t end)
203 {
204         phys_addr_t start_addr = addr;
205         pte_t *pte, *start_pte;
206 
207         start_pte = pte = pte_offset_kernel(pmd, addr);
208         do {
209                 if (!pte_none(*pte)) {
210                         pte_t old_pte = *pte;
211 
212                         kvm_set_pte(pte, __pte(0));
213                         kvm_tlb_flush_vmid_ipa(kvm, addr);
214 
215                         /* No need to invalidate the cache for device mappings */
216                         if ((pte_val(old_pte) & PAGE_S2_DEVICE) != PAGE_S2_DEVICE)
217                                 kvm_flush_dcache_pte(old_pte);
218 
219                         put_page(virt_to_page(pte));
220                 }
221         } while (pte++, addr += PAGE_SIZE, addr != end);
222 
223         if (kvm_pte_table_empty(kvm, start_pte))
224                 clear_pmd_entry(kvm, pmd, start_addr);
225 }
226 
227 static void unmap_pmds(struct kvm *kvm, pud_t *pud,
228                        phys_addr_t addr, phys_addr_t end)
229 {
230         phys_addr_t next, start_addr = addr;
231         pmd_t *pmd, *start_pmd;
232 
233         start_pmd = pmd = pmd_offset(pud, addr);
234         do {
235                 next = kvm_pmd_addr_end(addr, end);
236                 if (!pmd_none(*pmd)) {
237                         if (kvm_pmd_huge(*pmd)) {
238                                 pmd_t old_pmd = *pmd;
239 
240                                 pmd_clear(pmd);
241                                 kvm_tlb_flush_vmid_ipa(kvm, addr);
242 
243                                 kvm_flush_dcache_pmd(old_pmd);
244 
245                                 put_page(virt_to_page(pmd));
246                         } else {
247                                 unmap_ptes(kvm, pmd, addr, next);
248                         }
249                 }
250         } while (pmd++, addr = next, addr != end);
251 
252         if (kvm_pmd_table_empty(kvm, start_pmd))
253                 clear_pud_entry(kvm, pud, start_addr);
254 }
255 
256 static void unmap_puds(struct kvm *kvm, pgd_t *pgd,
257                        phys_addr_t addr, phys_addr_t end)
258 {
259         phys_addr_t next, start_addr = addr;
260         pud_t *pud, *start_pud;
261 
262         start_pud = pud = pud_offset(pgd, addr);
263         do {
264                 next = kvm_pud_addr_end(addr, end);
265                 if (!pud_none(*pud)) {
266                         if (pud_huge(*pud)) {
267                                 pud_t old_pud = *pud;
268 
269                                 pud_clear(pud);
270                                 kvm_tlb_flush_vmid_ipa(kvm, addr);
271 
272                                 kvm_flush_dcache_pud(old_pud);
273 
274                                 put_page(virt_to_page(pud));
275                         } else {
276                                 unmap_pmds(kvm, pud, addr, next);
277                         }
278                 }
279         } while (pud++, addr = next, addr != end);
280 
281         if (kvm_pud_table_empty(kvm, start_pud))
282                 clear_pgd_entry(kvm, pgd, start_addr);
283 }
284 
285 
286 static void unmap_range(struct kvm *kvm, pgd_t *pgdp,
287                         phys_addr_t start, u64 size)
288 {
289         pgd_t *pgd;
290         phys_addr_t addr = start, end = start + size;
291         phys_addr_t next;
292 
293         pgd = pgdp + kvm_pgd_index(addr);
294         do {
295                 next = kvm_pgd_addr_end(addr, end);
296                 if (!pgd_none(*pgd))
297                         unmap_puds(kvm, pgd, addr, next);
298         } while (pgd++, addr = next, addr != end);
299 }
300 
301 static void stage2_flush_ptes(struct kvm *kvm, pmd_t *pmd,
302                               phys_addr_t addr, phys_addr_t end)
303 {
304         pte_t *pte;
305 
306         pte = pte_offset_kernel(pmd, addr);
307         do {
308                 if (!pte_none(*pte) &&
309                     (pte_val(*pte) & PAGE_S2_DEVICE) != PAGE_S2_DEVICE)
310                         kvm_flush_dcache_pte(*pte);
311         } while (pte++, addr += PAGE_SIZE, addr != end);
312 }
313 
314 static void stage2_flush_pmds(struct kvm *kvm, pud_t *pud,
315                               phys_addr_t addr, phys_addr_t end)
316 {
317         pmd_t *pmd;
318         phys_addr_t next;
319 
320         pmd = pmd_offset(pud, addr);
321         do {
322                 next = kvm_pmd_addr_end(addr, end);
323                 if (!pmd_none(*pmd)) {
324                         if (kvm_pmd_huge(*pmd))
325                                 kvm_flush_dcache_pmd(*pmd);
326                         else
327                                 stage2_flush_ptes(kvm, pmd, addr, next);
328                 }
329         } while (pmd++, addr = next, addr != end);
330 }
331 
332 static void stage2_flush_puds(struct kvm *kvm, pgd_t *pgd,
333                               phys_addr_t addr, phys_addr_t end)
334 {
335         pud_t *pud;
336         phys_addr_t next;
337 
338         pud = pud_offset(pgd, addr);
339         do {
340                 next = kvm_pud_addr_end(addr, end);
341                 if (!pud_none(*pud)) {
342                         if (pud_huge(*pud))
343                                 kvm_flush_dcache_pud(*pud);
344                         else
345                                 stage2_flush_pmds(kvm, pud, addr, next);
346                 }
347         } while (pud++, addr = next, addr != end);
348 }
349 
350 static void stage2_flush_memslot(struct kvm *kvm,
351                                  struct kvm_memory_slot *memslot)
352 {
353         phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
354         phys_addr_t end = addr + PAGE_SIZE * memslot->npages;
355         phys_addr_t next;
356         pgd_t *pgd;
357 
358         pgd = kvm->arch.pgd + kvm_pgd_index(addr);
359         do {
360                 next = kvm_pgd_addr_end(addr, end);
361                 stage2_flush_puds(kvm, pgd, addr, next);
362         } while (pgd++, addr = next, addr != end);
363 }
364 
365 /**
366  * stage2_flush_vm - Invalidate cache for pages mapped in stage 2
367  * @kvm: The struct kvm pointer
368  *
369  * Go through the stage 2 page tables and invalidate any cache lines
370  * backing memory already mapped to the VM.
371  */
372 static void stage2_flush_vm(struct kvm *kvm)
373 {
374         struct kvm_memslots *slots;
375         struct kvm_memory_slot *memslot;
376         int idx;
377 
378         idx = srcu_read_lock(&kvm->srcu);
379         spin_lock(&kvm->mmu_lock);
380 
381         slots = kvm_memslots(kvm);
382         kvm_for_each_memslot(memslot, slots)
383                 stage2_flush_memslot(kvm, memslot);
384 
385         spin_unlock(&kvm->mmu_lock);
386         srcu_read_unlock(&kvm->srcu, idx);
387 }
388 
389 /**
390  * free_boot_hyp_pgd - free HYP boot page tables
391  *
392  * Free the HYP boot page tables. The bounce page is also freed.
393  */
394 void free_boot_hyp_pgd(void)
395 {
396         mutex_lock(&kvm_hyp_pgd_mutex);
397 
398         if (boot_hyp_pgd) {
399                 unmap_range(NULL, boot_hyp_pgd, hyp_idmap_start, PAGE_SIZE);
400                 unmap_range(NULL, boot_hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);
401                 free_pages((unsigned long)boot_hyp_pgd, hyp_pgd_order);
402                 boot_hyp_pgd = NULL;
403         }
404 
405         if (hyp_pgd)
406                 unmap_range(NULL, hyp_pgd, TRAMPOLINE_VA, PAGE_SIZE);
407 
408         mutex_unlock(&kvm_hyp_pgd_mutex);
409 }
410 
411 /**
412  * free_hyp_pgds - free Hyp-mode page tables
413  *
414  * Assumes hyp_pgd is a page table used strictly in Hyp-mode and
415  * therefore contains either mappings in the kernel memory area (above
416  * PAGE_OFFSET), or device mappings in the vmalloc range (from
417  * VMALLOC_START to VMALLOC_END).
418  *
419  * boot_hyp_pgd should only map two pages for the init code.
420  */
421 void free_hyp_pgds(void)
422 {
423         unsigned long addr;
424 
425         free_boot_hyp_pgd();
426 
427         mutex_lock(&kvm_hyp_pgd_mutex);
428 
429         if (hyp_pgd) {
430                 for (addr = PAGE_OFFSET; virt_addr_valid(addr); addr += PGDIR_SIZE)
431                         unmap_range(NULL, hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE);
432                 for (addr = VMALLOC_START; is_vmalloc_addr((void*)addr); addr += PGDIR_SIZE)
433                         unmap_range(NULL, hyp_pgd, KERN_TO_HYP(addr), PGDIR_SIZE);
434 
435                 free_pages((unsigned long)hyp_pgd, hyp_pgd_order);
436                 hyp_pgd = NULL;
437         }
438         if (merged_hyp_pgd) {
439                 clear_page(merged_hyp_pgd);
440                 free_page((unsigned long)merged_hyp_pgd);
441                 merged_hyp_pgd = NULL;
442         }
443 
444         mutex_unlock(&kvm_hyp_pgd_mutex);
445 }
446 
447 static void create_hyp_pte_mappings(pmd_t *pmd, unsigned long start,
448                                     unsigned long end, unsigned long pfn,
449                                     pgprot_t prot)
450 {
451         pte_t *pte;
452         unsigned long addr;
453 
454         addr = start;
455         do {
456                 pte = pte_offset_kernel(pmd, addr);
457                 kvm_set_pte(pte, pfn_pte(pfn, prot));
458                 get_page(virt_to_page(pte));
459                 kvm_flush_dcache_to_poc(pte, sizeof(*pte));
460                 pfn++;
461         } while (addr += PAGE_SIZE, addr != end);
462 }
463 
464 static int create_hyp_pmd_mappings(pud_t *pud, unsigned long start,
465                                    unsigned long end, unsigned long pfn,
466                                    pgprot_t prot)
467 {
468         pmd_t *pmd;
469         pte_t *pte;
470         unsigned long addr, next;
471 
472         addr = start;
473         do {
474                 pmd = pmd_offset(pud, addr);
475 
476                 BUG_ON(pmd_sect(*pmd));
477 
478                 if (pmd_none(*pmd)) {
479                         pte = pte_alloc_one_kernel(NULL, addr);
480                         if (!pte) {
481                                 kvm_err("Cannot allocate Hyp pte\n");
482                                 return -ENOMEM;
483                         }
484                         pmd_populate_kernel(NULL, pmd, pte);
485                         get_page(virt_to_page(pmd));
486                         kvm_flush_dcache_to_poc(pmd, sizeof(*pmd));
487                 }
488 
489                 next = pmd_addr_end(addr, end);
490 
491                 create_hyp_pte_mappings(pmd, addr, next, pfn, prot);
492                 pfn += (next - addr) >> PAGE_SHIFT;
493         } while (addr = next, addr != end);
494 
495         return 0;
496 }
497 
498 static int create_hyp_pud_mappings(pgd_t *pgd, unsigned long start,
499                                    unsigned long end, unsigned long pfn,
500                                    pgprot_t prot)
501 {
502         pud_t *pud;
503         pmd_t *pmd;
504         unsigned long addr, next;
505         int ret;
506 
507         addr = start;
508         do {
509                 pud = pud_offset(pgd, addr);
510 
511                 if (pud_none_or_clear_bad(pud)) {
512                         pmd = pmd_alloc_one(NULL, addr);
513                         if (!pmd) {
514                                 kvm_err("Cannot allocate Hyp pmd\n");
515                                 return -ENOMEM;
516                         }
517                         pud_populate(NULL, pud, pmd);
518                         get_page(virt_to_page(pud));
519                         kvm_flush_dcache_to_poc(pud, sizeof(*pud));
520                 }
521 
522                 next = pud_addr_end(addr, end);
523                 ret = create_hyp_pmd_mappings(pud, addr, next, pfn, prot);
524                 if (ret)
525                         return ret;
526                 pfn += (next - addr) >> PAGE_SHIFT;
527         } while (addr = next, addr != end);
528 
529         return 0;
530 }
531 
532 static int __create_hyp_mappings(pgd_t *pgdp,
533                                  unsigned long start, unsigned long end,
534                                  unsigned long pfn, pgprot_t prot)
535 {
536         pgd_t *pgd;
537         pud_t *pud;
538         unsigned long addr, next;
539         int err = 0;
540 
541         mutex_lock(&kvm_hyp_pgd_mutex);
542         addr = start & PAGE_MASK;
543         end = PAGE_ALIGN(end);
544         do {
545                 pgd = pgdp + pgd_index(addr);
546 
547                 if (pgd_none(*pgd)) {
548                         pud = pud_alloc_one(NULL, addr);
549                         if (!pud) {
550                                 kvm_err("Cannot allocate Hyp pud\n");
551                                 err = -ENOMEM;
552                                 goto out;
553                         }
554                         pgd_populate(NULL, pgd, pud);
555                         get_page(virt_to_page(pgd));
556                         kvm_flush_dcache_to_poc(pgd, sizeof(*pgd));
557                 }
558 
559                 next = pgd_addr_end(addr, end);
560                 err = create_hyp_pud_mappings(pgd, addr, next, pfn, prot);
561                 if (err)
562                         goto out;
563                 pfn += (next - addr) >> PAGE_SHIFT;
564         } while (addr = next, addr != end);
565 out:
566         mutex_unlock(&kvm_hyp_pgd_mutex);
567         return err;
568 }
569 
570 static phys_addr_t kvm_kaddr_to_phys(void *kaddr)
571 {
572         if (!is_vmalloc_addr(kaddr)) {
573                 BUG_ON(!virt_addr_valid(kaddr));
574                 return __pa(kaddr);
575         } else {
576                 return page_to_phys(vmalloc_to_page(kaddr)) +
577                        offset_in_page(kaddr);
578         }
579 }
580 
581 /**
582  * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode
583  * @from:       The virtual kernel start address of the range
584  * @to:         The virtual kernel end address of the range (exclusive)
585  *
586  * The same virtual address as the kernel virtual address is also used
587  * in Hyp-mode mapping (modulo HYP_PAGE_OFFSET) to the same underlying
588  * physical pages.
589  */
590 int create_hyp_mappings(void *from, void *to)
591 {
592         phys_addr_t phys_addr;
593         unsigned long virt_addr;
594         unsigned long start = KERN_TO_HYP((unsigned long)from);
595         unsigned long end = KERN_TO_HYP((unsigned long)to);
596 
597         start = start & PAGE_MASK;
598         end = PAGE_ALIGN(end);
599 
600         for (virt_addr = start; virt_addr < end; virt_addr += PAGE_SIZE) {
601                 int err;
602 
603                 phys_addr = kvm_kaddr_to_phys(from + virt_addr - start);
604                 err = __create_hyp_mappings(hyp_pgd, virt_addr,
605                                             virt_addr + PAGE_SIZE,
606                                             __phys_to_pfn(phys_addr),
607                                             PAGE_HYP);
608                 if (err)
609                         return err;
610         }
611 
612         return 0;
613 }
614 
615 /**
616  * create_hyp_io_mappings - duplicate a kernel IO mapping into Hyp mode
617  * @from:       The kernel start VA of the range
618  * @to:         The kernel end VA of the range (exclusive)
619  * @phys_addr:  The physical start address which gets mapped
620  *
621  * The resulting HYP VA is the same as the kernel VA, modulo
622  * HYP_PAGE_OFFSET.
623  */
624 int create_hyp_io_mappings(void *from, void *to, phys_addr_t phys_addr)
625 {
626         unsigned long start = KERN_TO_HYP((unsigned long)from);
627         unsigned long end = KERN_TO_HYP((unsigned long)to);
628 
629         /* Check for a valid kernel IO mapping */
630         if (!is_vmalloc_addr(from) || !is_vmalloc_addr(to - 1))
631                 return -EINVAL;
632 
633         return __create_hyp_mappings(hyp_pgd, start, end,
634                                      __phys_to_pfn(phys_addr), PAGE_HYP_DEVICE);
635 }
636 
637 /* Free the HW pgd, one page at a time */
638 static void kvm_free_hwpgd(void *hwpgd)
639 {
640         free_pages_exact(hwpgd, kvm_get_hwpgd_size());
641 }
642 
643 /* Allocate the HW PGD, making sure that each page gets its own refcount */
644 static void *kvm_alloc_hwpgd(void)
645 {
646         unsigned int size = kvm_get_hwpgd_size();
647 
648         return alloc_pages_exact(size, GFP_KERNEL | __GFP_ZERO);
649 }
650 
651 /**
652  * kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation.
653  * @kvm:        The KVM struct pointer for the VM.
654  *
655  * Allocates the 1st level table only of size defined by S2_PGD_ORDER (can
656  * support either full 40-bit input addresses or limited to 32-bit input
657  * addresses). Clears the allocated pages.
658  *
659  * Note we don't need locking here as this is only called when the VM is
660  * created, which can only be done once.
661  */
662 int kvm_alloc_stage2_pgd(struct kvm *kvm)
663 {
664         pgd_t *pgd;
665         void *hwpgd;
666 
667         if (kvm->arch.pgd != NULL) {
668                 kvm_err("kvm_arch already initialized?\n");
669                 return -EINVAL;
670         }
671 
672         hwpgd = kvm_alloc_hwpgd();
673         if (!hwpgd)
674                 return -ENOMEM;
675 
676         /* When the kernel uses more levels of page tables than the
677          * guest, we allocate a fake PGD and pre-populate it to point
678          * to the next-level page table, which will be the real
679          * initial page table pointed to by the VTTBR.
680          *
681          * When KVM_PREALLOC_LEVEL==2, we allocate a single page for
682          * the PMD and the kernel will use folded pud.
683          * When KVM_PREALLOC_LEVEL==1, we allocate 2 consecutive PUD
684          * pages.
685          */
686         if (KVM_PREALLOC_LEVEL > 0) {
687                 int i;
688 
689                 /*
690                  * Allocate fake pgd for the page table manipulation macros to
691                  * work.  This is not used by the hardware and we have no
692                  * alignment requirement for this allocation.
693                  */
694                 pgd = kmalloc(PTRS_PER_S2_PGD * sizeof(pgd_t),
695                                 GFP_KERNEL | __GFP_ZERO);
696 
697                 if (!pgd) {
698                         kvm_free_hwpgd(hwpgd);
699                         return -ENOMEM;
700                 }
701 
702                 /* Plug the HW PGD into the fake one. */
703                 for (i = 0; i < PTRS_PER_S2_PGD; i++) {
704                         if (KVM_PREALLOC_LEVEL == 1)
705                                 pgd_populate(NULL, pgd + i,
706                                              (pud_t *)hwpgd + i * PTRS_PER_PUD);
707                         else if (KVM_PREALLOC_LEVEL == 2)
708                                 pud_populate(NULL, pud_offset(pgd, 0) + i,
709                                              (pmd_t *)hwpgd + i * PTRS_PER_PMD);
710                 }
711         } else {
712                 /*
713                  * Allocate actual first-level Stage-2 page table used by the
714                  * hardware for Stage-2 page table walks.
715                  */
716                 pgd = (pgd_t *)hwpgd;
717         }
718 
719         kvm_clean_pgd(pgd);
720         kvm->arch.pgd = pgd;
721         return 0;
722 }
723 
724 /**
725  * unmap_stage2_range -- Clear stage2 page table entries to unmap a range
726  * @kvm:   The VM pointer
727  * @start: The intermediate physical base address of the range to unmap
728  * @size:  The size of the area to unmap
729  *
730  * Clear a range of stage-2 mappings, lowering the various ref-counts.  Must
731  * be called while holding mmu_lock (unless for freeing the stage2 pgd before
732  * destroying the VM), otherwise another faulting VCPU may come in and mess
733  * with things behind our backs.
734  */
735 static void unmap_stage2_range(struct kvm *kvm, phys_addr_t start, u64 size)
736 {
737         unmap_range(kvm, kvm->arch.pgd, start, size);
738 }
739 
740 static void stage2_unmap_memslot(struct kvm *kvm,
741                                  struct kvm_memory_slot *memslot)
742 {
743         hva_t hva = memslot->userspace_addr;
744         phys_addr_t addr = memslot->base_gfn << PAGE_SHIFT;
745         phys_addr_t size = PAGE_SIZE * memslot->npages;
746         hva_t reg_end = hva + size;
747 
748         /*
749          * A memory region could potentially cover multiple VMAs, and any holes
750          * between them, so iterate over all of them to find out if we should
751          * unmap any of them.
752          *
753          *     +--------------------------------------------+
754          * +---------------+----------------+   +----------------+
755          * |   : VMA 1     |      VMA 2     |   |    VMA 3  :    |
756          * +---------------+----------------+   +----------------+
757          *     |               memory region                |
758          *     +--------------------------------------------+
759          */
760         do {
761                 struct vm_area_struct *vma = find_vma(current->mm, hva);
762                 hva_t vm_start, vm_end;
763 
764                 if (!vma || vma->vm_start >= reg_end)
765                         break;
766 
767                 /*
768                  * Take the intersection of this VMA with the memory region
769                  */
770                 vm_start = max(hva, vma->vm_start);
771                 vm_end = min(reg_end, vma->vm_end);
772 
773                 if (!(vma->vm_flags & VM_PFNMAP)) {
774                         gpa_t gpa = addr + (vm_start - memslot->userspace_addr);
775                         unmap_stage2_range(kvm, gpa, vm_end - vm_start);
776                 }
777                 hva = vm_end;
778         } while (hva < reg_end);
779 }
780 
781 /**
782  * stage2_unmap_vm - Unmap Stage-2 RAM mappings
783  * @kvm: The struct kvm pointer
784  *
785  * Go through the memregions and unmap any reguler RAM
786  * backing memory already mapped to the VM.
787  */
788 void stage2_unmap_vm(struct kvm *kvm)
789 {
790         struct kvm_memslots *slots;
791         struct kvm_memory_slot *memslot;
792         int idx;
793 
794         idx = srcu_read_lock(&kvm->srcu);
795         spin_lock(&kvm->mmu_lock);
796 
797         slots = kvm_memslots(kvm);
798         kvm_for_each_memslot(memslot, slots)
799                 stage2_unmap_memslot(kvm, memslot);
800 
801         spin_unlock(&kvm->mmu_lock);
802         srcu_read_unlock(&kvm->srcu, idx);
803 }
804 
805 /**
806  * kvm_free_stage2_pgd - free all stage-2 tables
807  * @kvm:        The KVM struct pointer for the VM.
808  *
809  * Walks the level-1 page table pointed to by kvm->arch.pgd and frees all
810  * underlying level-2 and level-3 tables before freeing the actual level-1 table
811  * and setting the struct pointer to NULL.
812  *
813  * Note we don't need locking here as this is only called when the VM is
814  * destroyed, which can only be done once.
815  */
816 void kvm_free_stage2_pgd(struct kvm *kvm)
817 {
818         if (kvm->arch.pgd == NULL)
819                 return;
820 
821         unmap_stage2_range(kvm, 0, KVM_PHYS_SIZE);
822         kvm_free_hwpgd(kvm_get_hwpgd(kvm));
823         if (KVM_PREALLOC_LEVEL > 0)
824                 kfree(kvm->arch.pgd);
825 
826         kvm->arch.pgd = NULL;
827 }
828 
829 static pud_t *stage2_get_pud(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
830                              phys_addr_t addr)
831 {
832         pgd_t *pgd;
833         pud_t *pud;
834 
835         pgd = kvm->arch.pgd + kvm_pgd_index(addr);
836         if (WARN_ON(pgd_none(*pgd))) {
837                 if (!cache)
838                         return NULL;
839                 pud = mmu_memory_cache_alloc(cache);
840                 pgd_populate(NULL, pgd, pud);
841                 get_page(virt_to_page(pgd));
842         }
843 
844         return pud_offset(pgd, addr);
845 }
846 
847 static pmd_t *stage2_get_pmd(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
848                              phys_addr_t addr)
849 {
850         pud_t *pud;
851         pmd_t *pmd;
852 
853         pud = stage2_get_pud(kvm, cache, addr);
854         if (pud_none(*pud)) {
855                 if (!cache)
856                         return NULL;
857                 pmd = mmu_memory_cache_alloc(cache);
858                 pud_populate(NULL, pud, pmd);
859                 get_page(virt_to_page(pud));
860         }
861 
862         return pmd_offset(pud, addr);
863 }
864 
865 static int stage2_set_pmd_huge(struct kvm *kvm, struct kvm_mmu_memory_cache
866                                *cache, phys_addr_t addr, const pmd_t *new_pmd)
867 {
868         pmd_t *pmd, old_pmd;
869 
870         pmd = stage2_get_pmd(kvm, cache, addr);
871         VM_BUG_ON(!pmd);
872 
873         /*
874          * Mapping in huge pages should only happen through a fault.  If a
875          * page is merged into a transparent huge page, the individual
876          * subpages of that huge page should be unmapped through MMU
877          * notifiers before we get here.
878          *
879          * Merging of CompoundPages is not supported; they should become
880          * splitting first, unmapped, merged, and mapped back in on-demand.
881          */
882         VM_BUG_ON(pmd_present(*pmd) && pmd_pfn(*pmd) != pmd_pfn(*new_pmd));
883 
884         old_pmd = *pmd;
885         kvm_set_pmd(pmd, *new_pmd);
886         if (pmd_present(old_pmd))
887                 kvm_tlb_flush_vmid_ipa(kvm, addr);
888         else
889                 get_page(virt_to_page(pmd));
890         return 0;
891 }
892 
893 static int stage2_set_pte(struct kvm *kvm, struct kvm_mmu_memory_cache *cache,
894                           phys_addr_t addr, const pte_t *new_pte,
895                           unsigned long flags)
896 {
897         pmd_t *pmd;
898         pte_t *pte, old_pte;
899         bool iomap = flags & KVM_S2PTE_FLAG_IS_IOMAP;
900         bool logging_active = flags & KVM_S2_FLAG_LOGGING_ACTIVE;
901 
902         VM_BUG_ON(logging_active && !cache);
903 
904         /* Create stage-2 page table mapping - Levels 0 and 1 */
905         pmd = stage2_get_pmd(kvm, cache, addr);
906         if (!pmd) {
907                 /*
908                  * Ignore calls from kvm_set_spte_hva for unallocated
909                  * address ranges.
910                  */
911                 return 0;
912         }
913 
914         /*
915          * While dirty page logging - dissolve huge PMD, then continue on to
916          * allocate page.
917          */
918         if (logging_active)
919                 stage2_dissolve_pmd(kvm, addr, pmd);
920 
921         /* Create stage-2 page mappings - Level 2 */
922         if (pmd_none(*pmd)) {
923                 if (!cache)
924                         return 0; /* ignore calls from kvm_set_spte_hva */
925                 pte = mmu_memory_cache_alloc(cache);
926                 kvm_clean_pte(pte);
927                 pmd_populate_kernel(NULL, pmd, pte);
928                 get_page(virt_to_page(pmd));
929         }
930 
931         pte = pte_offset_kernel(pmd, addr);
932 
933         if (iomap && pte_present(*pte))
934                 return -EFAULT;
935 
936         /* Create 2nd stage page table mapping - Level 3 */
937         old_pte = *pte;
938         kvm_set_pte(pte, *new_pte);
939         if (pte_present(old_pte))
940                 kvm_tlb_flush_vmid_ipa(kvm, addr);
941         else
942                 get_page(virt_to_page(pte));
943 
944         return 0;
945 }
946 
947 /**
948  * kvm_phys_addr_ioremap - map a device range to guest IPA
949  *
950  * @kvm:        The KVM pointer
951  * @guest_ipa:  The IPA at which to insert the mapping
952  * @pa:         The physical address of the device
953  * @size:       The size of the mapping
954  */
955 int kvm_phys_addr_ioremap(struct kvm *kvm, phys_addr_t guest_ipa,
956                           phys_addr_t pa, unsigned long size, bool writable)
957 {
958         phys_addr_t addr, end;
959         int ret = 0;
960         unsigned long pfn;
961         struct kvm_mmu_memory_cache cache = { 0, };
962 
963         end = (guest_ipa + size + PAGE_SIZE - 1) & PAGE_MASK;
964         pfn = __phys_to_pfn(pa);
965 
966         for (addr = guest_ipa; addr < end; addr += PAGE_SIZE) {
967                 pte_t pte = pfn_pte(pfn, PAGE_S2_DEVICE);
968 
969                 if (writable)
970                         kvm_set_s2pte_writable(&pte);
971 
972                 ret = mmu_topup_memory_cache(&cache, KVM_MMU_CACHE_MIN_PAGES,
973                                                 KVM_NR_MEM_OBJS);
974                 if (ret)
975                         goto out;
976                 spin_lock(&kvm->mmu_lock);
977                 ret = stage2_set_pte(kvm, &cache, addr, &pte,
978                                                 KVM_S2PTE_FLAG_IS_IOMAP);
979                 spin_unlock(&kvm->mmu_lock);
980                 if (ret)
981                         goto out;
982 
983                 pfn++;
984         }
985 
986 out:
987         mmu_free_memory_cache(&cache);
988         return ret;
989 }
990 
991 static bool transparent_hugepage_adjust(pfn_t *pfnp, phys_addr_t *ipap)
992 {
993         pfn_t pfn = *pfnp;
994         gfn_t gfn = *ipap >> PAGE_SHIFT;
995 
996         if (PageTransCompound(pfn_to_page(pfn))) {
997                 unsigned long mask;
998                 /*
999                  * The address we faulted on is backed by a transparent huge
1000                  * page.  However, because we map the compound huge page and
1001                  * not the individual tail page, we need to transfer the
1002                  * refcount to the head page.  We have to be careful that the
1003                  * THP doesn't start to split while we are adjusting the
1004                  * refcounts.
1005                  *
1006                  * We are sure this doesn't happen, because mmu_notifier_retry
1007                  * was successful and we are holding the mmu_lock, so if this
1008                  * THP is trying to split, it will be blocked in the mmu
1009                  * notifier before touching any of the pages, specifically
1010                  * before being able to call __split_huge_page_refcount().
1011                  *
1012                  * We can therefore safely transfer the refcount from PG_tail
1013                  * to PG_head and switch the pfn from a tail page to the head
1014                  * page accordingly.
1015                  */
1016                 mask = PTRS_PER_PMD - 1;
1017                 VM_BUG_ON((gfn & mask) != (pfn & mask));
1018                 if (pfn & mask) {
1019                         *ipap &= PMD_MASK;
1020                         kvm_release_pfn_clean(pfn);
1021                         pfn &= ~mask;
1022                         kvm_get_pfn(pfn);
1023                         *pfnp = pfn;
1024                 }
1025 
1026                 return true;
1027         }
1028 
1029         return false;
1030 }
1031 
1032 static bool kvm_is_write_fault(struct kvm_vcpu *vcpu)
1033 {
1034         if (kvm_vcpu_trap_is_iabt(vcpu))
1035                 return false;
1036 
1037         return kvm_vcpu_dabt_iswrite(vcpu);
1038 }
1039 
1040 static bool kvm_is_device_pfn(unsigned long pfn)
1041 {
1042         return !pfn_valid(pfn);
1043 }
1044 
1045 /**
1046  * stage2_wp_ptes - write protect PMD range
1047  * @pmd:        pointer to pmd entry
1048  * @addr:       range start address
1049  * @end:        range end address
1050  */
1051 static void stage2_wp_ptes(pmd_t *pmd, phys_addr_t addr, phys_addr_t end)
1052 {
1053         pte_t *pte;
1054 
1055         pte = pte_offset_kernel(pmd, addr);
1056         do {
1057                 if (!pte_none(*pte)) {
1058                         if (!kvm_s2pte_readonly(pte))
1059                                 kvm_set_s2pte_readonly(pte);
1060                 }
1061         } while (pte++, addr += PAGE_SIZE, addr != end);
1062 }
1063 
1064 /**
1065  * stage2_wp_pmds - write protect PUD range
1066  * @pud:        pointer to pud entry
1067  * @addr:       range start address
1068  * @end:        range end address
1069  */
1070 static void stage2_wp_pmds(pud_t *pud, phys_addr_t addr, phys_addr_t end)
1071 {
1072         pmd_t *pmd;
1073         phys_addr_t next;
1074 
1075         pmd = pmd_offset(pud, addr);
1076 
1077         do {
1078                 next = kvm_pmd_addr_end(addr, end);
1079                 if (!pmd_none(*pmd)) {
1080                         if (kvm_pmd_huge(*pmd)) {
1081                                 if (!kvm_s2pmd_readonly(pmd))
1082                                         kvm_set_s2pmd_readonly(pmd);
1083                         } else {
1084                                 stage2_wp_ptes(pmd, addr, next);
1085                         }
1086                 }
1087         } while (pmd++, addr = next, addr != end);
1088 }
1089 
1090 /**
1091   * stage2_wp_puds - write protect PGD range
1092   * @pgd:       pointer to pgd entry
1093   * @addr:      range start address
1094   * @end:       range end address
1095   *
1096   * Process PUD entries, for a huge PUD we cause a panic.
1097   */
1098 static void  stage2_wp_puds(pgd_t *pgd, phys_addr_t addr, phys_addr_t end)
1099 {
1100         pud_t *pud;
1101         phys_addr_t next;
1102 
1103         pud = pud_offset(pgd, addr);
1104         do {
1105                 next = kvm_pud_addr_end(addr, end);
1106                 if (!pud_none(*pud)) {
1107                         /* TODO:PUD not supported, revisit later if supported */
1108                         BUG_ON(kvm_pud_huge(*pud));
1109                         stage2_wp_pmds(pud, addr, next);
1110                 }
1111         } while (pud++, addr = next, addr != end);
1112 }
1113 
1114 /**
1115  * stage2_wp_range() - write protect stage2 memory region range
1116  * @kvm:        The KVM pointer
1117  * @addr:       Start address of range
1118  * @end:        End address of range
1119  */
1120 static void stage2_wp_range(struct kvm *kvm, phys_addr_t addr, phys_addr_t end)
1121 {
1122         pgd_t *pgd;
1123         phys_addr_t next;
1124 
1125         pgd = kvm->arch.pgd + kvm_pgd_index(addr);
1126         do {
1127                 /*
1128                  * Release kvm_mmu_lock periodically if the memory region is
1129                  * large. Otherwise, we may see kernel panics with
1130                  * CONFIG_DETECT_HUNG_TASK, CONFIG_LOCKUP_DETECTOR,
1131                  * CONFIG_LOCKDEP. Additionally, holding the lock too long
1132                  * will also starve other vCPUs.
1133                  */
1134                 if (need_resched() || spin_needbreak(&kvm->mmu_lock))
1135                         cond_resched_lock(&kvm->mmu_lock);
1136 
1137                 next = kvm_pgd_addr_end(addr, end);
1138                 if (pgd_present(*pgd))
1139                         stage2_wp_puds(pgd, addr, next);
1140         } while (pgd++, addr = next, addr != end);
1141 }
1142 
1143 /**
1144  * kvm_mmu_wp_memory_region() - write protect stage 2 entries for memory slot
1145  * @kvm:        The KVM pointer
1146  * @slot:       The memory slot to write protect
1147  *
1148  * Called to start logging dirty pages after memory region
1149  * KVM_MEM_LOG_DIRTY_PAGES operation is called. After this function returns
1150  * all present PMD and PTEs are write protected in the memory region.
1151  * Afterwards read of dirty page log can be called.
1152  *
1153  * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired,
1154  * serializing operations for VM memory regions.
1155  */
1156 void kvm_mmu_wp_memory_region(struct kvm *kvm, int slot)
1157 {
1158         struct kvm_memslots *slots = kvm_memslots(kvm);
1159         struct kvm_memory_slot *memslot = id_to_memslot(slots, slot);
1160         phys_addr_t start = memslot->base_gfn << PAGE_SHIFT;
1161         phys_addr_t end = (memslot->base_gfn + memslot->npages) << PAGE_SHIFT;
1162 
1163         spin_lock(&kvm->mmu_lock);
1164         stage2_wp_range(kvm, start, end);
1165         spin_unlock(&kvm->mmu_lock);
1166         kvm_flush_remote_tlbs(kvm);
1167 }
1168 
1169 /**
1170  * kvm_mmu_write_protect_pt_masked() - write protect dirty pages
1171  * @kvm:        The KVM pointer
1172  * @slot:       The memory slot associated with mask
1173  * @gfn_offset: The gfn offset in memory slot
1174  * @mask:       The mask of dirty pages at offset 'gfn_offset' in this memory
1175  *              slot to be write protected
1176  *
1177  * Walks bits set in mask write protects the associated pte's. Caller must
1178  * acquire kvm_mmu_lock.
1179  */
1180 static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm,
1181                 struct kvm_memory_slot *slot,
1182                 gfn_t gfn_offset, unsigned long mask)
1183 {
1184         phys_addr_t base_gfn = slot->base_gfn + gfn_offset;
1185         phys_addr_t start = (base_gfn +  __ffs(mask)) << PAGE_SHIFT;
1186         phys_addr_t end = (base_gfn + __fls(mask) + 1) << PAGE_SHIFT;
1187 
1188         stage2_wp_range(kvm, start, end);
1189 }
1190 
1191 /*
1192  * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected
1193  * dirty pages.
1194  *
1195  * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to
1196  * enable dirty logging for them.
1197  */
1198 void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm *kvm,
1199                 struct kvm_memory_slot *slot,
1200                 gfn_t gfn_offset, unsigned long mask)
1201 {
1202         kvm_mmu_write_protect_pt_masked(kvm, slot, gfn_offset, mask);
1203 }
1204 
1205 static void coherent_cache_guest_page(struct kvm_vcpu *vcpu, pfn_t pfn,
1206                                       unsigned long size, bool uncached)
1207 {
1208         __coherent_cache_guest_page(vcpu, pfn, size, uncached);
1209 }
1210 
1211 static int user_mem_abort(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa,
1212                           struct kvm_memory_slot *memslot, unsigned long hva,
1213                           unsigned long fault_status)
1214 {
1215         int ret;
1216         bool write_fault, writable, hugetlb = false, force_pte = false;
1217         unsigned long mmu_seq;
1218         gfn_t gfn = fault_ipa >> PAGE_SHIFT;
1219         struct kvm *kvm = vcpu->kvm;
1220         struct kvm_mmu_memory_cache *memcache = &vcpu->arch.mmu_page_cache;
1221         struct vm_area_struct *vma;
1222         pfn_t pfn;
1223         pgprot_t mem_type = PAGE_S2;
1224         bool fault_ipa_uncached;
1225         bool logging_active = memslot_is_logging(memslot);
1226         unsigned long flags = 0;
1227 
1228         write_fault = kvm_is_write_fault(vcpu);
1229         if (fault_status == FSC_PERM && !write_fault) {
1230                 kvm_err("Unexpected L2 read permission error\n");
1231                 return -EFAULT;
1232         }
1233 
1234         /* Let's check if we will get back a huge page backed by hugetlbfs */
1235         down_read(&current->mm->mmap_sem);
1236         vma = find_vma_intersection(current->mm, hva, hva + 1);
1237         if (unlikely(!vma)) {
1238                 kvm_err("Failed to find VMA for hva 0x%lx\n", hva);
1239                 up_read(&current->mm->mmap_sem);
1240                 return -EFAULT;
1241         }
1242 
1243         if (is_vm_hugetlb_page(vma) && !logging_active) {
1244                 hugetlb = true;
1245                 gfn = (fault_ipa & PMD_MASK) >> PAGE_SHIFT;
1246         } else {
1247                 /*
1248                  * Pages belonging to memslots that don't have the same
1249                  * alignment for userspace and IPA cannot be mapped using
1250                  * block descriptors even if the pages belong to a THP for
1251                  * the process, because the stage-2 block descriptor will
1252                  * cover more than a single THP and we loose atomicity for
1253                  * unmapping, updates, and splits of the THP or other pages
1254                  * in the stage-2 block range.
1255                  */
1256                 if ((memslot->userspace_addr & ~PMD_MASK) !=
1257                     ((memslot->base_gfn << PAGE_SHIFT) & ~PMD_MASK))
1258                         force_pte = true;
1259         }
1260         up_read(&current->mm->mmap_sem);
1261 
1262         /* We need minimum second+third level pages */
1263         ret = mmu_topup_memory_cache(memcache, KVM_MMU_CACHE_MIN_PAGES,
1264                                      KVM_NR_MEM_OBJS);
1265         if (ret)
1266                 return ret;
1267 
1268         mmu_seq = vcpu->kvm->mmu_notifier_seq;
1269         /*
1270          * Ensure the read of mmu_notifier_seq happens before we call
1271          * gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk
1272          * the page we just got a reference to gets unmapped before we have a
1273          * chance to grab the mmu_lock, which ensure that if the page gets
1274          * unmapped afterwards, the call to kvm_unmap_hva will take it away
1275          * from us again properly. This smp_rmb() interacts with the smp_wmb()
1276          * in kvm_mmu_notifier_invalidate_<page|range_end>.
1277          */
1278         smp_rmb();
1279 
1280         pfn = gfn_to_pfn_prot(kvm, gfn, write_fault, &writable);
1281         if (is_error_pfn(pfn))
1282                 return -EFAULT;
1283 
1284         if (kvm_is_device_pfn(pfn)) {
1285                 mem_type = PAGE_S2_DEVICE;
1286                 flags |= KVM_S2PTE_FLAG_IS_IOMAP;
1287         } else if (logging_active) {
1288                 /*
1289                  * Faults on pages in a memslot with logging enabled
1290                  * should not be mapped with huge pages (it introduces churn
1291                  * and performance degradation), so force a pte mapping.
1292                  */
1293                 force_pte = true;
1294                 flags |= KVM_S2_FLAG_LOGGING_ACTIVE;
1295 
1296                 /*
1297                  * Only actually map the page as writable if this was a write
1298                  * fault.
1299                  */
1300                 if (!write_fault)
1301                         writable = false;
1302         }
1303 
1304         spin_lock(&kvm->mmu_lock);
1305         if (mmu_notifier_retry(kvm, mmu_seq))
1306                 goto out_unlock;
1307 
1308         if (!hugetlb && !force_pte)
1309                 hugetlb = transparent_hugepage_adjust(&pfn, &fault_ipa);
1310 
1311         fault_ipa_uncached = memslot->flags & KVM_MEMSLOT_INCOHERENT;
1312 
1313         if (hugetlb) {
1314                 pmd_t new_pmd = pfn_pmd(pfn, mem_type);
1315                 new_pmd = pmd_mkhuge(new_pmd);
1316                 if (writable) {
1317                         kvm_set_s2pmd_writable(&new_pmd);
1318                         kvm_set_pfn_dirty(pfn);
1319                 }
1320                 coherent_cache_guest_page(vcpu, pfn, PMD_SIZE, fault_ipa_uncached);
1321                 ret = stage2_set_pmd_huge(kvm, memcache, fault_ipa, &new_pmd);
1322         } else {
1323                 pte_t new_pte = pfn_pte(pfn, mem_type);
1324 
1325                 if (writable) {
1326                         kvm_set_s2pte_writable(&new_pte);
1327                         kvm_set_pfn_dirty(pfn);
1328                         mark_page_dirty(kvm, gfn);
1329                 }
1330                 coherent_cache_guest_page(vcpu, pfn, PAGE_SIZE, fault_ipa_uncached);
1331                 ret = stage2_set_pte(kvm, memcache, fault_ipa, &new_pte, flags);
1332         }
1333 
1334 out_unlock:
1335         spin_unlock(&kvm->mmu_lock);
1336         kvm_set_pfn_accessed(pfn);
1337         kvm_release_pfn_clean(pfn);
1338         return ret;
1339 }
1340 
1341 /*
1342  * Resolve the access fault by making the page young again.
1343  * Note that because the faulting entry is guaranteed not to be
1344  * cached in the TLB, we don't need to invalidate anything.
1345  */
1346 static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
1347 {
1348         pmd_t *pmd;
1349         pte_t *pte;
1350         pfn_t pfn;
1351         bool pfn_valid = false;
1352 
1353         trace_kvm_access_fault(fault_ipa);
1354 
1355         spin_lock(&vcpu->kvm->mmu_lock);
1356 
1357         pmd = stage2_get_pmd(vcpu->kvm, NULL, fault_ipa);
1358         if (!pmd || pmd_none(*pmd))     /* Nothing there */
1359                 goto out;
1360 
1361         if (kvm_pmd_huge(*pmd)) {       /* THP, HugeTLB */
1362                 *pmd = pmd_mkyoung(*pmd);
1363                 pfn = pmd_pfn(*pmd);
1364                 pfn_valid = true;
1365                 goto out;
1366         }
1367 
1368         pte = pte_offset_kernel(pmd, fault_ipa);
1369         if (pte_none(*pte))             /* Nothing there either */
1370                 goto out;
1371 
1372         *pte = pte_mkyoung(*pte);       /* Just a page... */
1373         pfn = pte_pfn(*pte);
1374         pfn_valid = true;
1375 out:
1376         spin_unlock(&vcpu->kvm->mmu_lock);
1377         if (pfn_valid)
1378                 kvm_set_pfn_accessed(pfn);
1379 }
1380 
1381 /**
1382  * kvm_handle_guest_abort - handles all 2nd stage aborts
1383  * @vcpu:       the VCPU pointer
1384  * @run:        the kvm_run structure
1385  *
1386  * Any abort that gets to the host is almost guaranteed to be caused by a
1387  * missing second stage translation table entry, which can mean that either the
1388  * guest simply needs more memory and we must allocate an appropriate page or it
1389  * can mean that the guest tried to access I/O memory, which is emulated by user
1390  * space. The distinction is based on the IPA causing the fault and whether this
1391  * memory region has been registered as standard RAM by user space.
1392  */
1393 int kvm_handle_guest_abort(struct kvm_vcpu *vcpu, struct kvm_run *run)
1394 {
1395         unsigned long fault_status;
1396         phys_addr_t fault_ipa;
1397         struct kvm_memory_slot *memslot;
1398         unsigned long hva;
1399         bool is_iabt, write_fault, writable;
1400         gfn_t gfn;
1401         int ret, idx;
1402 
1403         is_iabt = kvm_vcpu_trap_is_iabt(vcpu);
1404         fault_ipa = kvm_vcpu_get_fault_ipa(vcpu);
1405 
1406         trace_kvm_guest_fault(*vcpu_pc(vcpu), kvm_vcpu_get_hsr(vcpu),
1407                               kvm_vcpu_get_hfar(vcpu), fault_ipa);
1408 
1409         /* Check the stage-2 fault is trans. fault or write fault */
1410         fault_status = kvm_vcpu_trap_get_fault_type(vcpu);
1411         if (fault_status != FSC_FAULT && fault_status != FSC_PERM &&
1412             fault_status != FSC_ACCESS) {
1413                 kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n",
1414                         kvm_vcpu_trap_get_class(vcpu),
1415                         (unsigned long)kvm_vcpu_trap_get_fault(vcpu),
1416                         (unsigned long)kvm_vcpu_get_hsr(vcpu));
1417                 return -EFAULT;
1418         }
1419 
1420         idx = srcu_read_lock(&vcpu->kvm->srcu);
1421 
1422         gfn = fault_ipa >> PAGE_SHIFT;
1423         memslot = gfn_to_memslot(vcpu->kvm, gfn);
1424         hva = gfn_to_hva_memslot_prot(memslot, gfn, &writable);
1425         write_fault = kvm_is_write_fault(vcpu);
1426         if (kvm_is_error_hva(hva) || (write_fault && !writable)) {
1427                 if (is_iabt) {
1428                         /* Prefetch Abort on I/O address */
1429                         kvm_inject_pabt(vcpu, kvm_vcpu_get_hfar(vcpu));
1430                         ret = 1;
1431                         goto out_unlock;
1432                 }
1433 
1434                 /*
1435                  * The IPA is reported as [MAX:12], so we need to
1436                  * complement it with the bottom 12 bits from the
1437                  * faulting VA. This is always 12 bits, irrespective
1438                  * of the page size.
1439                  */
1440                 fault_ipa |= kvm_vcpu_get_hfar(vcpu) & ((1 << 12) - 1);
1441                 ret = io_mem_abort(vcpu, run, fault_ipa);
1442                 goto out_unlock;
1443         }
1444 
1445         /* Userspace should not be able to register out-of-bounds IPAs */
1446         VM_BUG_ON(fault_ipa >= KVM_PHYS_SIZE);
1447 
1448         if (fault_status == FSC_ACCESS) {
1449                 handle_access_fault(vcpu, fault_ipa);
1450                 ret = 1;
1451                 goto out_unlock;
1452         }
1453 
1454         ret = user_mem_abort(vcpu, fault_ipa, memslot, hva, fault_status);
1455         if (ret == 0)
1456                 ret = 1;
1457 out_unlock:
1458         srcu_read_unlock(&vcpu->kvm->srcu, idx);
1459         return ret;
1460 }
1461 
1462 static int handle_hva_to_gpa(struct kvm *kvm,
1463                              unsigned long start,
1464                              unsigned long end,
1465                              int (*handler)(struct kvm *kvm,
1466                                             gpa_t gpa, void *data),
1467                              void *data)
1468 {
1469         struct kvm_memslots *slots;
1470         struct kvm_memory_slot *memslot;
1471         int ret = 0;
1472 
1473         slots = kvm_memslots(kvm);
1474 
1475         /* we only care about the pages that the guest sees */
1476         kvm_for_each_memslot(memslot, slots) {
1477                 unsigned long hva_start, hva_end;
1478                 gfn_t gfn, gfn_end;
1479 
1480                 hva_start = max(start, memslot->userspace_addr);
1481                 hva_end = min(end, memslot->userspace_addr +
1482                                         (memslot->npages << PAGE_SHIFT));
1483                 if (hva_start >= hva_end)
1484                         continue;
1485 
1486                 /*
1487                  * {gfn(page) | page intersects with [hva_start, hva_end)} =
1488                  * {gfn_start, gfn_start+1, ..., gfn_end-1}.
1489                  */
1490                 gfn = hva_to_gfn_memslot(hva_start, memslot);
1491                 gfn_end = hva_to_gfn_memslot(hva_end + PAGE_SIZE - 1, memslot);
1492 
1493                 for (; gfn < gfn_end; ++gfn) {
1494                         gpa_t gpa = gfn << PAGE_SHIFT;
1495                         ret |= handler(kvm, gpa, data);
1496                 }
1497         }
1498 
1499         return ret;
1500 }
1501 
1502 static int kvm_unmap_hva_handler(struct kvm *kvm, gpa_t gpa, void *data)
1503 {
1504         unmap_stage2_range(kvm, gpa, PAGE_SIZE);
1505         return 0;
1506 }
1507 
1508 int kvm_unmap_hva(struct kvm *kvm, unsigned long hva)
1509 {
1510         unsigned long end = hva + PAGE_SIZE;
1511 
1512         if (!kvm->arch.pgd)
1513                 return 0;
1514 
1515         trace_kvm_unmap_hva(hva);
1516         handle_hva_to_gpa(kvm, hva, end, &kvm_unmap_hva_handler, NULL);
1517         return 0;
1518 }
1519 
1520 int kvm_unmap_hva_range(struct kvm *kvm,
1521                         unsigned long start, unsigned long end)
1522 {
1523         if (!kvm->arch.pgd)
1524                 return 0;
1525 
1526         trace_kvm_unmap_hva_range(start, end);
1527         handle_hva_to_gpa(kvm, start, end, &kvm_unmap_hva_handler, NULL);
1528         return 0;
1529 }
1530 
1531 static int kvm_set_spte_handler(struct kvm *kvm, gpa_t gpa, void *data)
1532 {
1533         pte_t *pte = (pte_t *)data;
1534 
1535         /*
1536          * We can always call stage2_set_pte with KVM_S2PTE_FLAG_LOGGING_ACTIVE
1537          * flag clear because MMU notifiers will have unmapped a huge PMD before
1538          * calling ->change_pte() (which in turn calls kvm_set_spte_hva()) and
1539          * therefore stage2_set_pte() never needs to clear out a huge PMD
1540          * through this calling path.
1541          */
1542         stage2_set_pte(kvm, NULL, gpa, pte, 0);
1543         return 0;
1544 }
1545 
1546 
1547 void kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
1548 {
1549         unsigned long end = hva + PAGE_SIZE;
1550         pte_t stage2_pte;
1551 
1552         if (!kvm->arch.pgd)
1553                 return;
1554 
1555         trace_kvm_set_spte_hva(hva);
1556         stage2_pte = pfn_pte(pte_pfn(pte), PAGE_S2);
1557         handle_hva_to_gpa(kvm, hva, end, &kvm_set_spte_handler, &stage2_pte);
1558 }
1559 
1560 static int kvm_age_hva_handler(struct kvm *kvm, gpa_t gpa, void *data)
1561 {
1562         pmd_t *pmd;
1563         pte_t *pte;
1564 
1565         pmd = stage2_get_pmd(kvm, NULL, gpa);
1566         if (!pmd || pmd_none(*pmd))     /* Nothing there */
1567                 return 0;
1568 
1569         if (kvm_pmd_huge(*pmd)) {       /* THP, HugeTLB */
1570                 if (pmd_young(*pmd)) {
1571                         *pmd = pmd_mkold(*pmd);
1572                         return 1;
1573                 }
1574 
1575                 return 0;
1576         }
1577 
1578         pte = pte_offset_kernel(pmd, gpa);
1579         if (pte_none(*pte))
1580                 return 0;
1581 
1582         if (pte_young(*pte)) {
1583                 *pte = pte_mkold(*pte); /* Just a page... */
1584                 return 1;
1585         }
1586 
1587         return 0;
1588 }
1589 
1590 static int kvm_test_age_hva_handler(struct kvm *kvm, gpa_t gpa, void *data)
1591 {
1592         pmd_t *pmd;
1593         pte_t *pte;
1594 
1595         pmd = stage2_get_pmd(kvm, NULL, gpa);
1596         if (!pmd || pmd_none(*pmd))     /* Nothing there */
1597                 return 0;
1598 
1599         if (kvm_pmd_huge(*pmd))         /* THP, HugeTLB */
1600                 return pmd_young(*pmd);
1601 
1602         pte = pte_offset_kernel(pmd, gpa);
1603         if (!pte_none(*pte))            /* Just a page... */
1604                 return pte_young(*pte);
1605 
1606         return 0;
1607 }
1608 
1609 int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end)
1610 {
1611         trace_kvm_age_hva(start, end);
1612         return handle_hva_to_gpa(kvm, start, end, kvm_age_hva_handler, NULL);
1613 }
1614 
1615 int kvm_test_age_hva(struct kvm *kvm, unsigned long hva)
1616 {
1617         trace_kvm_test_age_hva(hva);
1618         return handle_hva_to_gpa(kvm, hva, hva, kvm_test_age_hva_handler, NULL);
1619 }
1620 
1621 void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu)
1622 {
1623         mmu_free_memory_cache(&vcpu->arch.mmu_page_cache);
1624 }
1625 
1626 phys_addr_t kvm_mmu_get_httbr(void)
1627 {
1628         if (__kvm_cpu_uses_extended_idmap())
1629                 return virt_to_phys(merged_hyp_pgd);
1630         else
1631                 return virt_to_phys(hyp_pgd);
1632 }
1633 
1634 phys_addr_t kvm_mmu_get_boot_httbr(void)
1635 {
1636         if (__kvm_cpu_uses_extended_idmap())
1637                 return virt_to_phys(merged_hyp_pgd);
1638         else
1639                 return virt_to_phys(boot_hyp_pgd);
1640 }
1641 
1642 phys_addr_t kvm_get_idmap_vector(void)
1643 {
1644         return hyp_idmap_vector;
1645 }
1646 
1647 int kvm_mmu_init(void)
1648 {
1649         int err;
1650 
1651         hyp_idmap_start = kvm_virt_to_phys(__hyp_idmap_text_start);
1652         hyp_idmap_end = kvm_virt_to_phys(__hyp_idmap_text_end);
1653         hyp_idmap_vector = kvm_virt_to_phys(__kvm_hyp_init);
1654 
1655         /*
1656          * We rely on the linker script to ensure at build time that the HYP
1657          * init code does not cross a page boundary.
1658          */
1659         BUG_ON((hyp_idmap_start ^ (hyp_idmap_end - 1)) & PAGE_MASK);
1660 
1661         hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, hyp_pgd_order);
1662         boot_hyp_pgd = (pgd_t *)__get_free_pages(GFP_KERNEL | __GFP_ZERO, hyp_pgd_order);
1663 
1664         if (!hyp_pgd || !boot_hyp_pgd) {
1665                 kvm_err("Hyp mode PGD not allocated\n");
1666                 err = -ENOMEM;
1667                 goto out;
1668         }
1669 
1670         /* Create the idmap in the boot page tables */
1671         err =   __create_hyp_mappings(boot_hyp_pgd,
1672                                       hyp_idmap_start, hyp_idmap_end,
1673                                       __phys_to_pfn(hyp_idmap_start),
1674                                       PAGE_HYP);
1675 
1676         if (err) {
1677                 kvm_err("Failed to idmap %lx-%lx\n",
1678                         hyp_idmap_start, hyp_idmap_end);
1679                 goto out;
1680         }
1681 
1682         if (__kvm_cpu_uses_extended_idmap()) {
1683                 merged_hyp_pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
1684                 if (!merged_hyp_pgd) {
1685                         kvm_err("Failed to allocate extra HYP pgd\n");
1686                         goto out;
1687                 }
1688                 __kvm_extend_hypmap(boot_hyp_pgd, hyp_pgd, merged_hyp_pgd,
1689                                     hyp_idmap_start);
1690                 return 0;
1691         }
1692 
1693         /* Map the very same page at the trampoline VA */
1694         err =   __create_hyp_mappings(boot_hyp_pgd,
1695                                       TRAMPOLINE_VA, TRAMPOLINE_VA + PAGE_SIZE,
1696                                       __phys_to_pfn(hyp_idmap_start),
1697                                       PAGE_HYP);
1698         if (err) {
1699                 kvm_err("Failed to map trampoline @%lx into boot HYP pgd\n",
1700                         TRAMPOLINE_VA);
1701                 goto out;
1702         }
1703 
1704         /* Map the same page again into the runtime page tables */
1705         err =   __create_hyp_mappings(hyp_pgd,
1706                                       TRAMPOLINE_VA, TRAMPOLINE_VA + PAGE_SIZE,
1707                                       __phys_to_pfn(hyp_idmap_start),
1708                                       PAGE_HYP);
1709         if (err) {
1710                 kvm_err("Failed to map trampoline @%lx into runtime HYP pgd\n",
1711                         TRAMPOLINE_VA);
1712                 goto out;
1713         }
1714 
1715         return 0;
1716 out:
1717         free_hyp_pgds();
1718         return err;
1719 }
1720 
1721 void kvm_arch_commit_memory_region(struct kvm *kvm,
1722                                    const struct kvm_userspace_memory_region *mem,
1723                                    const struct kvm_memory_slot *old,
1724                                    const struct kvm_memory_slot *new,
1725                                    enum kvm_mr_change change)
1726 {
1727         /*
1728          * At this point memslot has been committed and there is an
1729          * allocated dirty_bitmap[], dirty pages will be be tracked while the
1730          * memory slot is write protected.
1731          */
1732         if (change != KVM_MR_DELETE && mem->flags & KVM_MEM_LOG_DIRTY_PAGES)
1733                 kvm_mmu_wp_memory_region(kvm, mem->slot);
1734 }
1735 
1736 int kvm_arch_prepare_memory_region(struct kvm *kvm,
1737                                    struct kvm_memory_slot *memslot,
1738                                    const struct kvm_userspace_memory_region *mem,
1739                                    enum kvm_mr_change change)
1740 {
1741         hva_t hva = mem->userspace_addr;
1742         hva_t reg_end = hva + mem->memory_size;
1743         bool writable = !(mem->flags & KVM_MEM_READONLY);
1744         int ret = 0;
1745 
1746         if (change != KVM_MR_CREATE && change != KVM_MR_MOVE &&
1747                         change != KVM_MR_FLAGS_ONLY)
1748                 return 0;
1749 
1750         /*
1751          * Prevent userspace from creating a memory region outside of the IPA
1752          * space addressable by the KVM guest IPA space.
1753          */
1754         if (memslot->base_gfn + memslot->npages >=
1755             (KVM_PHYS_SIZE >> PAGE_SHIFT))
1756                 return -EFAULT;
1757 
1758         /*
1759          * A memory region could potentially cover multiple VMAs, and any holes
1760          * between them, so iterate over all of them to find out if we can map
1761          * any of them right now.
1762          *
1763          *     +--------------------------------------------+
1764          * +---------------+----------------+   +----------------+
1765          * |   : VMA 1     |      VMA 2     |   |    VMA 3  :    |
1766          * +---------------+----------------+   +----------------+
1767          *     |               memory region                |
1768          *     +--------------------------------------------+
1769          */
1770         do {
1771                 struct vm_area_struct *vma = find_vma(current->mm, hva);
1772                 hva_t vm_start, vm_end;
1773 
1774                 if (!vma || vma->vm_start >= reg_end)
1775                         break;
1776 
1777                 /*
1778                  * Mapping a read-only VMA is only allowed if the
1779                  * memory region is configured as read-only.
1780                  */
1781                 if (writable && !(vma->vm_flags & VM_WRITE)) {
1782                         ret = -EPERM;
1783                         break;
1784                 }
1785 
1786                 /*
1787                  * Take the intersection of this VMA with the memory region
1788                  */
1789                 vm_start = max(hva, vma->vm_start);
1790                 vm_end = min(reg_end, vma->vm_end);
1791 
1792                 if (vma->vm_flags & VM_PFNMAP) {
1793                         gpa_t gpa = mem->guest_phys_addr +
1794                                     (vm_start - mem->userspace_addr);
1795                         phys_addr_t pa;
1796 
1797                         pa = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT;
1798                         pa += vm_start - vma->vm_start;
1799 
1800                         /* IO region dirty page logging not allowed */
1801                         if (memslot->flags & KVM_MEM_LOG_DIRTY_PAGES)
1802                                 return -EINVAL;
1803 
1804                         ret = kvm_phys_addr_ioremap(kvm, gpa, pa,
1805                                                     vm_end - vm_start,
1806                                                     writable);
1807                         if (ret)
1808                                 break;
1809                 }
1810                 hva = vm_end;
1811         } while (hva < reg_end);
1812 
1813         if (change == KVM_MR_FLAGS_ONLY)
1814                 return ret;
1815 
1816         spin_lock(&kvm->mmu_lock);
1817         if (ret)
1818                 unmap_stage2_range(kvm, mem->guest_phys_addr, mem->memory_size);
1819         else
1820                 stage2_flush_memslot(kvm, memslot);
1821         spin_unlock(&kvm->mmu_lock);
1822         return ret;
1823 }
1824 
1825 void kvm_arch_free_memslot(struct kvm *kvm, struct kvm_memory_slot *free,
1826                            struct kvm_memory_slot *dont)
1827 {
1828 }
1829 
1830 int kvm_arch_create_memslot(struct kvm *kvm, struct kvm_memory_slot *slot,
1831                             unsigned long npages)
1832 {
1833         /*
1834          * Readonly memslots are not incoherent with the caches by definition,
1835          * but in practice, they are used mostly to emulate ROMs or NOR flashes
1836          * that the guest may consider devices and hence map as uncached.
1837          * To prevent incoherency issues in these cases, tag all readonly
1838          * regions as incoherent.
1839          */
1840         if (slot->flags & KVM_MEM_READONLY)
1841                 slot->flags |= KVM_MEMSLOT_INCOHERENT;
1842         return 0;
1843 }
1844 
1845 void kvm_arch_memslots_updated(struct kvm *kvm, struct kvm_memslots *slots)
1846 {
1847 }
1848 
1849 void kvm_arch_flush_shadow_all(struct kvm *kvm)
1850 {
1851 }
1852 
1853 void kvm_arch_flush_shadow_memslot(struct kvm *kvm,
1854                                    struct kvm_memory_slot *slot)
1855 {
1856         gpa_t gpa = slot->base_gfn << PAGE_SHIFT;
1857         phys_addr_t size = slot->npages << PAGE_SHIFT;
1858 
1859         spin_lock(&kvm->mmu_lock);
1860         unmap_stage2_range(kvm, gpa, size);
1861         spin_unlock(&kvm->mmu_lock);
1862 }
1863 
1864 /*
1865  * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
1866  *
1867  * Main problems:
1868  * - S/W ops are local to a CPU (not broadcast)
1869  * - We have line migration behind our back (speculation)
1870  * - System caches don't support S/W at all (damn!)
1871  *
1872  * In the face of the above, the best we can do is to try and convert
1873  * S/W ops to VA ops. Because the guest is not allowed to infer the
1874  * S/W to PA mapping, it can only use S/W to nuke the whole cache,
1875  * which is a rather good thing for us.
1876  *
1877  * Also, it is only used when turning caches on/off ("The expected
1878  * usage of the cache maintenance instructions that operate by set/way
1879  * is associated with the cache maintenance instructions associated
1880  * with the powerdown and powerup of caches, if this is required by
1881  * the implementation.").
1882  *
1883  * We use the following policy:
1884  *
1885  * - If we trap a S/W operation, we enable VM trapping to detect
1886  *   caches being turned on/off, and do a full clean.
1887  *
1888  * - We flush the caches on both caches being turned on and off.
1889  *
1890  * - Once the caches are enabled, we stop trapping VM ops.
1891  */
1892 void kvm_set_way_flush(struct kvm_vcpu *vcpu)
1893 {
1894         unsigned long hcr = vcpu_get_hcr(vcpu);
1895 
1896         /*
1897          * If this is the first time we do a S/W operation
1898          * (i.e. HCR_TVM not set) flush the whole memory, and set the
1899          * VM trapping.
1900          *
1901          * Otherwise, rely on the VM trapping to wait for the MMU +
1902          * Caches to be turned off. At that point, we'll be able to
1903          * clean the caches again.
1904          */
1905         if (!(hcr & HCR_TVM)) {
1906                 trace_kvm_set_way_flush(*vcpu_pc(vcpu),
1907                                         vcpu_has_cache_enabled(vcpu));
1908                 stage2_flush_vm(vcpu->kvm);
1909                 vcpu_set_hcr(vcpu, hcr | HCR_TVM);
1910         }
1911 }
1912 
1913 void kvm_toggle_cache(struct kvm_vcpu *vcpu, bool was_enabled)
1914 {
1915         bool now_enabled = vcpu_has_cache_enabled(vcpu);
1916 
1917         /*
1918          * If switching the MMU+caches on, need to invalidate the caches.
1919          * If switching it off, need to clean the caches.
1920          * Clean + invalidate does the trick always.
1921          */
1922         if (now_enabled != was_enabled)
1923                 stage2_flush_vm(vcpu->kvm);
1924 
1925         /* Caches are now on, stop trapping VM ops (until a S/W op) */
1926         if (now_enabled)
1927                 vcpu_set_hcr(vcpu, vcpu_get_hcr(vcpu) & ~HCR_TVM);
1928 
1929         trace_kvm_toggle_cache(*vcpu_pc(vcpu), was_enabled, now_enabled);
1930 }
1931 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp