2 * Copyright (C) 2012 - Virtual Open Systems and Columbia University
3 * Author: Christoffer Dall <c.dall@virtualopensystems.com>
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.
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.
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.
19 #include <linux/mman.h>
20 #include <linux/kvm_host.h>
22 #include <linux/hugetlb.h>
23 #include <linux/sched/signal.h>
24 #include <trace/events/kvm.h>
25 #include <asm/pgalloc.h>
26 #include <asm/cacheflush.h>
27 #include <asm/kvm_arm.h>
28 #include <asm/kvm_mmu.h>
29 #include <asm/kvm_mmio.h>
30 #include <asm/kvm_asm.h>
31 #include <asm/kvm_emulate.h>
33 #include <asm/system_misc.h>
37 static pgd_t
*boot_hyp_pgd
;
38 static pgd_t
*hyp_pgd
;
39 static pgd_t
*merged_hyp_pgd
;
40 static DEFINE_MUTEX(kvm_hyp_pgd_mutex
);
42 static unsigned long hyp_idmap_start
;
43 static unsigned long hyp_idmap_end
;
44 static phys_addr_t hyp_idmap_vector
;
46 #define S2_PGD_SIZE (PTRS_PER_S2_PGD * sizeof(pgd_t))
47 #define hyp_pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t))
49 #define KVM_S2PTE_FLAG_IS_IOMAP (1UL << 0)
50 #define KVM_S2_FLAG_LOGGING_ACTIVE (1UL << 1)
52 static bool memslot_is_logging(struct kvm_memory_slot
*memslot
)
54 return memslot
->dirty_bitmap
&& !(memslot
->flags
& KVM_MEM_READONLY
);
58 * kvm_flush_remote_tlbs() - flush all VM TLB entries for v7/8
59 * @kvm: pointer to kvm structure.
61 * Interface to HYP function to flush all VM TLB entries
63 void kvm_flush_remote_tlbs(struct kvm
*kvm
)
65 kvm_call_hyp(__kvm_tlb_flush_vmid
, kvm
);
68 static void kvm_tlb_flush_vmid_ipa(struct kvm
*kvm
, phys_addr_t ipa
)
70 kvm_call_hyp(__kvm_tlb_flush_vmid_ipa
, kvm
, ipa
);
74 * D-Cache management functions. They take the page table entries by
75 * value, as they are flushing the cache using the kernel mapping (or
78 static void kvm_flush_dcache_pte(pte_t pte
)
80 __kvm_flush_dcache_pte(pte
);
83 static void kvm_flush_dcache_pmd(pmd_t pmd
)
85 __kvm_flush_dcache_pmd(pmd
);
88 static void kvm_flush_dcache_pud(pud_t pud
)
90 __kvm_flush_dcache_pud(pud
);
93 static bool kvm_is_device_pfn(unsigned long pfn
)
95 return !pfn_valid(pfn
);
99 * stage2_dissolve_pmd() - clear and flush huge PMD entry
100 * @kvm: pointer to kvm structure.
102 * @pmd: pmd pointer for IPA
104 * Function clears a PMD entry, flushes addr 1st and 2nd stage TLBs. Marks all
105 * pages in the range dirty.
107 static void stage2_dissolve_pmd(struct kvm
*kvm
, phys_addr_t addr
, pmd_t
*pmd
)
109 if (!pmd_thp_or_huge(*pmd
))
113 kvm_tlb_flush_vmid_ipa(kvm
, addr
);
114 put_page(virt_to_page(pmd
));
117 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache
*cache
,
122 BUG_ON(max
> KVM_NR_MEM_OBJS
);
123 if (cache
->nobjs
>= min
)
125 while (cache
->nobjs
< max
) {
126 page
= (void *)__get_free_page(PGALLOC_GFP
);
129 cache
->objects
[cache
->nobjs
++] = page
;
134 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache
*mc
)
137 free_page((unsigned long)mc
->objects
[--mc
->nobjs
]);
140 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache
*mc
)
144 BUG_ON(!mc
|| !mc
->nobjs
);
145 p
= mc
->objects
[--mc
->nobjs
];
149 static void clear_stage2_pgd_entry(struct kvm
*kvm
, pgd_t
*pgd
, phys_addr_t addr
)
151 pud_t
*pud_table __maybe_unused
= stage2_pud_offset(pgd
, 0UL);
152 stage2_pgd_clear(pgd
);
153 kvm_tlb_flush_vmid_ipa(kvm
, addr
);
154 stage2_pud_free(pud_table
);
155 put_page(virt_to_page(pgd
));
158 static void clear_stage2_pud_entry(struct kvm
*kvm
, pud_t
*pud
, phys_addr_t addr
)
160 pmd_t
*pmd_table __maybe_unused
= stage2_pmd_offset(pud
, 0);
161 VM_BUG_ON(stage2_pud_huge(*pud
));
162 stage2_pud_clear(pud
);
163 kvm_tlb_flush_vmid_ipa(kvm
, addr
);
164 stage2_pmd_free(pmd_table
);
165 put_page(virt_to_page(pud
));
168 static void clear_stage2_pmd_entry(struct kvm
*kvm
, pmd_t
*pmd
, phys_addr_t addr
)
170 pte_t
*pte_table
= pte_offset_kernel(pmd
, 0);
171 VM_BUG_ON(pmd_thp_or_huge(*pmd
));
173 kvm_tlb_flush_vmid_ipa(kvm
, addr
);
174 pte_free_kernel(NULL
, pte_table
);
175 put_page(virt_to_page(pmd
));
179 * Unmapping vs dcache management:
181 * If a guest maps certain memory pages as uncached, all writes will
182 * bypass the data cache and go directly to RAM. However, the CPUs
183 * can still speculate reads (not writes) and fill cache lines with
186 * Those cache lines will be *clean* cache lines though, so a
187 * clean+invalidate operation is equivalent to an invalidate
188 * operation, because no cache lines are marked dirty.
190 * Those clean cache lines could be filled prior to an uncached write
191 * by the guest, and the cache coherent IO subsystem would therefore
192 * end up writing old data to disk.
194 * This is why right after unmapping a page/section and invalidating
195 * the corresponding TLBs, we call kvm_flush_dcache_p*() to make sure
196 * the IO subsystem will never hit in the cache.
198 static void unmap_stage2_ptes(struct kvm
*kvm
, pmd_t
*pmd
,
199 phys_addr_t addr
, phys_addr_t end
)
201 phys_addr_t start_addr
= addr
;
202 pte_t
*pte
, *start_pte
;
204 start_pte
= pte
= pte_offset_kernel(pmd
, addr
);
206 if (!pte_none(*pte
)) {
207 pte_t old_pte
= *pte
;
209 kvm_set_pte(pte
, __pte(0));
210 kvm_tlb_flush_vmid_ipa(kvm
, addr
);
212 /* No need to invalidate the cache for device mappings */
213 if (!kvm_is_device_pfn(pte_pfn(old_pte
)))
214 kvm_flush_dcache_pte(old_pte
);
216 put_page(virt_to_page(pte
));
218 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
220 if (stage2_pte_table_empty(start_pte
))
221 clear_stage2_pmd_entry(kvm
, pmd
, start_addr
);
224 static void unmap_stage2_pmds(struct kvm
*kvm
, pud_t
*pud
,
225 phys_addr_t addr
, phys_addr_t end
)
227 phys_addr_t next
, start_addr
= addr
;
228 pmd_t
*pmd
, *start_pmd
;
230 start_pmd
= pmd
= stage2_pmd_offset(pud
, addr
);
232 next
= stage2_pmd_addr_end(addr
, end
);
233 if (!pmd_none(*pmd
)) {
234 if (pmd_thp_or_huge(*pmd
)) {
235 pmd_t old_pmd
= *pmd
;
238 kvm_tlb_flush_vmid_ipa(kvm
, addr
);
240 kvm_flush_dcache_pmd(old_pmd
);
242 put_page(virt_to_page(pmd
));
244 unmap_stage2_ptes(kvm
, pmd
, addr
, next
);
247 } while (pmd
++, addr
= next
, addr
!= end
);
249 if (stage2_pmd_table_empty(start_pmd
))
250 clear_stage2_pud_entry(kvm
, pud
, start_addr
);
253 static void unmap_stage2_puds(struct kvm
*kvm
, pgd_t
*pgd
,
254 phys_addr_t addr
, phys_addr_t end
)
256 phys_addr_t next
, start_addr
= addr
;
257 pud_t
*pud
, *start_pud
;
259 start_pud
= pud
= stage2_pud_offset(pgd
, addr
);
261 next
= stage2_pud_addr_end(addr
, end
);
262 if (!stage2_pud_none(*pud
)) {
263 if (stage2_pud_huge(*pud
)) {
264 pud_t old_pud
= *pud
;
266 stage2_pud_clear(pud
);
267 kvm_tlb_flush_vmid_ipa(kvm
, addr
);
268 kvm_flush_dcache_pud(old_pud
);
269 put_page(virt_to_page(pud
));
271 unmap_stage2_pmds(kvm
, pud
, addr
, next
);
274 } while (pud
++, addr
= next
, addr
!= end
);
276 if (stage2_pud_table_empty(start_pud
))
277 clear_stage2_pgd_entry(kvm
, pgd
, start_addr
);
281 * unmap_stage2_range -- Clear stage2 page table entries to unmap a range
282 * @kvm: The VM pointer
283 * @start: The intermediate physical base address of the range to unmap
284 * @size: The size of the area to unmap
286 * Clear a range of stage-2 mappings, lowering the various ref-counts. Must
287 * be called while holding mmu_lock (unless for freeing the stage2 pgd before
288 * destroying the VM), otherwise another faulting VCPU may come in and mess
289 * with things behind our backs.
291 static void unmap_stage2_range(struct kvm
*kvm
, phys_addr_t start
, u64 size
)
294 phys_addr_t addr
= start
, end
= start
+ size
;
297 assert_spin_locked(&kvm
->mmu_lock
);
298 pgd
= kvm
->arch
.pgd
+ stage2_pgd_index(addr
);
301 * Make sure the page table is still active, as another thread
302 * could have possibly freed the page table, while we released
305 if (!READ_ONCE(kvm
->arch
.pgd
))
307 next
= stage2_pgd_addr_end(addr
, end
);
308 if (!stage2_pgd_none(*pgd
))
309 unmap_stage2_puds(kvm
, pgd
, addr
, next
);
311 * If the range is too large, release the kvm->mmu_lock
312 * to prevent starvation and lockup detector warnings.
315 cond_resched_lock(&kvm
->mmu_lock
);
316 } while (pgd
++, addr
= next
, addr
!= end
);
319 static void stage2_flush_ptes(struct kvm
*kvm
, pmd_t
*pmd
,
320 phys_addr_t addr
, phys_addr_t end
)
324 pte
= pte_offset_kernel(pmd
, addr
);
326 if (!pte_none(*pte
) && !kvm_is_device_pfn(pte_pfn(*pte
)))
327 kvm_flush_dcache_pte(*pte
);
328 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
331 static void stage2_flush_pmds(struct kvm
*kvm
, pud_t
*pud
,
332 phys_addr_t addr
, phys_addr_t end
)
337 pmd
= stage2_pmd_offset(pud
, addr
);
339 next
= stage2_pmd_addr_end(addr
, end
);
340 if (!pmd_none(*pmd
)) {
341 if (pmd_thp_or_huge(*pmd
))
342 kvm_flush_dcache_pmd(*pmd
);
344 stage2_flush_ptes(kvm
, pmd
, addr
, next
);
346 } while (pmd
++, addr
= next
, addr
!= end
);
349 static void stage2_flush_puds(struct kvm
*kvm
, pgd_t
*pgd
,
350 phys_addr_t addr
, phys_addr_t end
)
355 pud
= stage2_pud_offset(pgd
, addr
);
357 next
= stage2_pud_addr_end(addr
, end
);
358 if (!stage2_pud_none(*pud
)) {
359 if (stage2_pud_huge(*pud
))
360 kvm_flush_dcache_pud(*pud
);
362 stage2_flush_pmds(kvm
, pud
, addr
, next
);
364 } while (pud
++, addr
= next
, addr
!= end
);
367 static void stage2_flush_memslot(struct kvm
*kvm
,
368 struct kvm_memory_slot
*memslot
)
370 phys_addr_t addr
= memslot
->base_gfn
<< PAGE_SHIFT
;
371 phys_addr_t end
= addr
+ PAGE_SIZE
* memslot
->npages
;
375 pgd
= kvm
->arch
.pgd
+ stage2_pgd_index(addr
);
377 next
= stage2_pgd_addr_end(addr
, end
);
378 stage2_flush_puds(kvm
, pgd
, addr
, next
);
379 } while (pgd
++, addr
= next
, addr
!= end
);
383 * stage2_flush_vm - Invalidate cache for pages mapped in stage 2
384 * @kvm: The struct kvm pointer
386 * Go through the stage 2 page tables and invalidate any cache lines
387 * backing memory already mapped to the VM.
389 static void stage2_flush_vm(struct kvm
*kvm
)
391 struct kvm_memslots
*slots
;
392 struct kvm_memory_slot
*memslot
;
395 idx
= srcu_read_lock(&kvm
->srcu
);
396 spin_lock(&kvm
->mmu_lock
);
398 slots
= kvm_memslots(kvm
);
399 kvm_for_each_memslot(memslot
, slots
)
400 stage2_flush_memslot(kvm
, memslot
);
402 spin_unlock(&kvm
->mmu_lock
);
403 srcu_read_unlock(&kvm
->srcu
, idx
);
406 static void clear_hyp_pgd_entry(pgd_t
*pgd
)
408 pud_t
*pud_table __maybe_unused
= pud_offset(pgd
, 0UL);
410 pud_free(NULL
, pud_table
);
411 put_page(virt_to_page(pgd
));
414 static void clear_hyp_pud_entry(pud_t
*pud
)
416 pmd_t
*pmd_table __maybe_unused
= pmd_offset(pud
, 0);
417 VM_BUG_ON(pud_huge(*pud
));
419 pmd_free(NULL
, pmd_table
);
420 put_page(virt_to_page(pud
));
423 static void clear_hyp_pmd_entry(pmd_t
*pmd
)
425 pte_t
*pte_table
= pte_offset_kernel(pmd
, 0);
426 VM_BUG_ON(pmd_thp_or_huge(*pmd
));
428 pte_free_kernel(NULL
, pte_table
);
429 put_page(virt_to_page(pmd
));
432 static void unmap_hyp_ptes(pmd_t
*pmd
, phys_addr_t addr
, phys_addr_t end
)
434 pte_t
*pte
, *start_pte
;
436 start_pte
= pte
= pte_offset_kernel(pmd
, addr
);
438 if (!pte_none(*pte
)) {
439 kvm_set_pte(pte
, __pte(0));
440 put_page(virt_to_page(pte
));
442 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
444 if (hyp_pte_table_empty(start_pte
))
445 clear_hyp_pmd_entry(pmd
);
448 static void unmap_hyp_pmds(pud_t
*pud
, phys_addr_t addr
, phys_addr_t end
)
451 pmd_t
*pmd
, *start_pmd
;
453 start_pmd
= pmd
= pmd_offset(pud
, addr
);
455 next
= pmd_addr_end(addr
, end
);
456 /* Hyp doesn't use huge pmds */
458 unmap_hyp_ptes(pmd
, addr
, next
);
459 } while (pmd
++, addr
= next
, addr
!= end
);
461 if (hyp_pmd_table_empty(start_pmd
))
462 clear_hyp_pud_entry(pud
);
465 static void unmap_hyp_puds(pgd_t
*pgd
, phys_addr_t addr
, phys_addr_t end
)
468 pud_t
*pud
, *start_pud
;
470 start_pud
= pud
= pud_offset(pgd
, addr
);
472 next
= pud_addr_end(addr
, end
);
473 /* Hyp doesn't use huge puds */
475 unmap_hyp_pmds(pud
, addr
, next
);
476 } while (pud
++, addr
= next
, addr
!= end
);
478 if (hyp_pud_table_empty(start_pud
))
479 clear_hyp_pgd_entry(pgd
);
482 static void unmap_hyp_range(pgd_t
*pgdp
, phys_addr_t start
, u64 size
)
485 phys_addr_t addr
= start
, end
= start
+ size
;
489 * We don't unmap anything from HYP, except at the hyp tear down.
490 * Hence, we don't have to invalidate the TLBs here.
492 pgd
= pgdp
+ pgd_index(addr
);
494 next
= pgd_addr_end(addr
, end
);
496 unmap_hyp_puds(pgd
, addr
, next
);
497 } while (pgd
++, addr
= next
, addr
!= end
);
501 * free_hyp_pgds - free Hyp-mode page tables
503 * Assumes hyp_pgd is a page table used strictly in Hyp-mode and
504 * therefore contains either mappings in the kernel memory area (above
505 * PAGE_OFFSET), or device mappings in the vmalloc range (from
506 * VMALLOC_START to VMALLOC_END).
508 * boot_hyp_pgd should only map two pages for the init code.
510 void free_hyp_pgds(void)
514 mutex_lock(&kvm_hyp_pgd_mutex
);
517 unmap_hyp_range(boot_hyp_pgd
, hyp_idmap_start
, PAGE_SIZE
);
518 free_pages((unsigned long)boot_hyp_pgd
, hyp_pgd_order
);
523 unmap_hyp_range(hyp_pgd
, hyp_idmap_start
, PAGE_SIZE
);
524 for (addr
= PAGE_OFFSET
; virt_addr_valid(addr
); addr
+= PGDIR_SIZE
)
525 unmap_hyp_range(hyp_pgd
, kern_hyp_va(addr
), PGDIR_SIZE
);
526 for (addr
= VMALLOC_START
; is_vmalloc_addr((void*)addr
); addr
+= PGDIR_SIZE
)
527 unmap_hyp_range(hyp_pgd
, kern_hyp_va(addr
), PGDIR_SIZE
);
529 free_pages((unsigned long)hyp_pgd
, hyp_pgd_order
);
532 if (merged_hyp_pgd
) {
533 clear_page(merged_hyp_pgd
);
534 free_page((unsigned long)merged_hyp_pgd
);
535 merged_hyp_pgd
= NULL
;
538 mutex_unlock(&kvm_hyp_pgd_mutex
);
541 static void create_hyp_pte_mappings(pmd_t
*pmd
, unsigned long start
,
542 unsigned long end
, unsigned long pfn
,
550 pte
= pte_offset_kernel(pmd
, addr
);
551 kvm_set_pte(pte
, pfn_pte(pfn
, prot
));
552 get_page(virt_to_page(pte
));
553 kvm_flush_dcache_to_poc(pte
, sizeof(*pte
));
555 } while (addr
+= PAGE_SIZE
, addr
!= end
);
558 static int create_hyp_pmd_mappings(pud_t
*pud
, unsigned long start
,
559 unsigned long end
, unsigned long pfn
,
564 unsigned long addr
, next
;
568 pmd
= pmd_offset(pud
, addr
);
570 BUG_ON(pmd_sect(*pmd
));
572 if (pmd_none(*pmd
)) {
573 pte
= pte_alloc_one_kernel(NULL
, addr
);
575 kvm_err("Cannot allocate Hyp pte\n");
578 pmd_populate_kernel(NULL
, pmd
, pte
);
579 get_page(virt_to_page(pmd
));
580 kvm_flush_dcache_to_poc(pmd
, sizeof(*pmd
));
583 next
= pmd_addr_end(addr
, end
);
585 create_hyp_pte_mappings(pmd
, addr
, next
, pfn
, prot
);
586 pfn
+= (next
- addr
) >> PAGE_SHIFT
;
587 } while (addr
= next
, addr
!= end
);
592 static int create_hyp_pud_mappings(pgd_t
*pgd
, unsigned long start
,
593 unsigned long end
, unsigned long pfn
,
598 unsigned long addr
, next
;
603 pud
= pud_offset(pgd
, addr
);
605 if (pud_none_or_clear_bad(pud
)) {
606 pmd
= pmd_alloc_one(NULL
, addr
);
608 kvm_err("Cannot allocate Hyp pmd\n");
611 pud_populate(NULL
, pud
, pmd
);
612 get_page(virt_to_page(pud
));
613 kvm_flush_dcache_to_poc(pud
, sizeof(*pud
));
616 next
= pud_addr_end(addr
, end
);
617 ret
= create_hyp_pmd_mappings(pud
, addr
, next
, pfn
, prot
);
620 pfn
+= (next
- addr
) >> PAGE_SHIFT
;
621 } while (addr
= next
, addr
!= end
);
626 static int __create_hyp_mappings(pgd_t
*pgdp
,
627 unsigned long start
, unsigned long end
,
628 unsigned long pfn
, pgprot_t prot
)
632 unsigned long addr
, next
;
635 mutex_lock(&kvm_hyp_pgd_mutex
);
636 addr
= start
& PAGE_MASK
;
637 end
= PAGE_ALIGN(end
);
639 pgd
= pgdp
+ pgd_index(addr
);
641 if (pgd_none(*pgd
)) {
642 pud
= pud_alloc_one(NULL
, addr
);
644 kvm_err("Cannot allocate Hyp pud\n");
648 pgd_populate(NULL
, pgd
, pud
);
649 get_page(virt_to_page(pgd
));
650 kvm_flush_dcache_to_poc(pgd
, sizeof(*pgd
));
653 next
= pgd_addr_end(addr
, end
);
654 err
= create_hyp_pud_mappings(pgd
, addr
, next
, pfn
, prot
);
657 pfn
+= (next
- addr
) >> PAGE_SHIFT
;
658 } while (addr
= next
, addr
!= end
);
660 mutex_unlock(&kvm_hyp_pgd_mutex
);
664 static phys_addr_t
kvm_kaddr_to_phys(void *kaddr
)
666 if (!is_vmalloc_addr(kaddr
)) {
667 BUG_ON(!virt_addr_valid(kaddr
));
670 return page_to_phys(vmalloc_to_page(kaddr
)) +
671 offset_in_page(kaddr
);
676 * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode
677 * @from: The virtual kernel start address of the range
678 * @to: The virtual kernel end address of the range (exclusive)
679 * @prot: The protection to be applied to this range
681 * The same virtual address as the kernel virtual address is also used
682 * in Hyp-mode mapping (modulo HYP_PAGE_OFFSET) to the same underlying
685 int create_hyp_mappings(void *from
, void *to
, pgprot_t prot
)
687 phys_addr_t phys_addr
;
688 unsigned long virt_addr
;
689 unsigned long start
= kern_hyp_va((unsigned long)from
);
690 unsigned long end
= kern_hyp_va((unsigned long)to
);
692 if (is_kernel_in_hyp_mode())
695 start
= start
& PAGE_MASK
;
696 end
= PAGE_ALIGN(end
);
698 for (virt_addr
= start
; virt_addr
< end
; virt_addr
+= PAGE_SIZE
) {
701 phys_addr
= kvm_kaddr_to_phys(from
+ virt_addr
- start
);
702 err
= __create_hyp_mappings(hyp_pgd
, virt_addr
,
703 virt_addr
+ PAGE_SIZE
,
704 __phys_to_pfn(phys_addr
),
714 * create_hyp_io_mappings - duplicate a kernel IO mapping into Hyp mode
715 * @from: The kernel start VA of the range
716 * @to: The kernel end VA of the range (exclusive)
717 * @phys_addr: The physical start address which gets mapped
719 * The resulting HYP VA is the same as the kernel VA, modulo
722 int create_hyp_io_mappings(void *from
, void *to
, phys_addr_t phys_addr
)
724 unsigned long start
= kern_hyp_va((unsigned long)from
);
725 unsigned long end
= kern_hyp_va((unsigned long)to
);
727 if (is_kernel_in_hyp_mode())
730 /* Check for a valid kernel IO mapping */
731 if (!is_vmalloc_addr(from
) || !is_vmalloc_addr(to
- 1))
734 return __create_hyp_mappings(hyp_pgd
, start
, end
,
735 __phys_to_pfn(phys_addr
), PAGE_HYP_DEVICE
);
739 * kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation.
740 * @kvm: The KVM struct pointer for the VM.
742 * Allocates only the stage-2 HW PGD level table(s) (can support either full
743 * 40-bit input addresses or limited to 32-bit input addresses). Clears the
746 * Note we don't need locking here as this is only called when the VM is
747 * created, which can only be done once.
749 int kvm_alloc_stage2_pgd(struct kvm
*kvm
)
753 if (kvm
->arch
.pgd
!= NULL
) {
754 kvm_err("kvm_arch already initialized?\n");
758 /* Allocate the HW PGD, making sure that each page gets its own refcount */
759 pgd
= alloc_pages_exact(S2_PGD_SIZE
, GFP_KERNEL
| __GFP_ZERO
);
767 static void stage2_unmap_memslot(struct kvm
*kvm
,
768 struct kvm_memory_slot
*memslot
)
770 hva_t hva
= memslot
->userspace_addr
;
771 phys_addr_t addr
= memslot
->base_gfn
<< PAGE_SHIFT
;
772 phys_addr_t size
= PAGE_SIZE
* memslot
->npages
;
773 hva_t reg_end
= hva
+ size
;
776 * A memory region could potentially cover multiple VMAs, and any holes
777 * between them, so iterate over all of them to find out if we should
780 * +--------------------------------------------+
781 * +---------------+----------------+ +----------------+
782 * | : VMA 1 | VMA 2 | | VMA 3 : |
783 * +---------------+----------------+ +----------------+
785 * +--------------------------------------------+
788 struct vm_area_struct
*vma
= find_vma(current
->mm
, hva
);
789 hva_t vm_start
, vm_end
;
791 if (!vma
|| vma
->vm_start
>= reg_end
)
795 * Take the intersection of this VMA with the memory region
797 vm_start
= max(hva
, vma
->vm_start
);
798 vm_end
= min(reg_end
, vma
->vm_end
);
800 if (!(vma
->vm_flags
& VM_PFNMAP
)) {
801 gpa_t gpa
= addr
+ (vm_start
- memslot
->userspace_addr
);
802 unmap_stage2_range(kvm
, gpa
, vm_end
- vm_start
);
805 } while (hva
< reg_end
);
809 * stage2_unmap_vm - Unmap Stage-2 RAM mappings
810 * @kvm: The struct kvm pointer
812 * Go through the memregions and unmap any reguler RAM
813 * backing memory already mapped to the VM.
815 void stage2_unmap_vm(struct kvm
*kvm
)
817 struct kvm_memslots
*slots
;
818 struct kvm_memory_slot
*memslot
;
821 idx
= srcu_read_lock(&kvm
->srcu
);
822 down_read(¤t
->mm
->mmap_sem
);
823 spin_lock(&kvm
->mmu_lock
);
825 slots
= kvm_memslots(kvm
);
826 kvm_for_each_memslot(memslot
, slots
)
827 stage2_unmap_memslot(kvm
, memslot
);
829 spin_unlock(&kvm
->mmu_lock
);
830 up_read(¤t
->mm
->mmap_sem
);
831 srcu_read_unlock(&kvm
->srcu
, idx
);
835 * kvm_free_stage2_pgd - free all stage-2 tables
836 * @kvm: The KVM struct pointer for the VM.
838 * Walks the level-1 page table pointed to by kvm->arch.pgd and frees all
839 * underlying level-2 and level-3 tables before freeing the actual level-1 table
840 * and setting the struct pointer to NULL.
842 void kvm_free_stage2_pgd(struct kvm
*kvm
)
846 spin_lock(&kvm
->mmu_lock
);
848 unmap_stage2_range(kvm
, 0, KVM_PHYS_SIZE
);
849 pgd
= READ_ONCE(kvm
->arch
.pgd
);
850 kvm
->arch
.pgd
= NULL
;
852 spin_unlock(&kvm
->mmu_lock
);
854 /* Free the HW pgd, one page at a time */
856 free_pages_exact(pgd
, S2_PGD_SIZE
);
859 static pud_t
*stage2_get_pud(struct kvm
*kvm
, struct kvm_mmu_memory_cache
*cache
,
865 pgd
= kvm
->arch
.pgd
+ stage2_pgd_index(addr
);
866 if (WARN_ON(stage2_pgd_none(*pgd
))) {
869 pud
= mmu_memory_cache_alloc(cache
);
870 stage2_pgd_populate(pgd
, pud
);
871 get_page(virt_to_page(pgd
));
874 return stage2_pud_offset(pgd
, addr
);
877 static pmd_t
*stage2_get_pmd(struct kvm
*kvm
, struct kvm_mmu_memory_cache
*cache
,
883 pud
= stage2_get_pud(kvm
, cache
, addr
);
887 if (stage2_pud_none(*pud
)) {
890 pmd
= mmu_memory_cache_alloc(cache
);
891 stage2_pud_populate(pud
, pmd
);
892 get_page(virt_to_page(pud
));
895 return stage2_pmd_offset(pud
, addr
);
898 static int stage2_set_pmd_huge(struct kvm
*kvm
, struct kvm_mmu_memory_cache
899 *cache
, phys_addr_t addr
, const pmd_t
*new_pmd
)
903 pmd
= stage2_get_pmd(kvm
, cache
, addr
);
907 * Mapping in huge pages should only happen through a fault. If a
908 * page is merged into a transparent huge page, the individual
909 * subpages of that huge page should be unmapped through MMU
910 * notifiers before we get here.
912 * Merging of CompoundPages is not supported; they should become
913 * splitting first, unmapped, merged, and mapped back in on-demand.
915 VM_BUG_ON(pmd_present(*pmd
) && pmd_pfn(*pmd
) != pmd_pfn(*new_pmd
));
918 if (pmd_present(old_pmd
)) {
920 kvm_tlb_flush_vmid_ipa(kvm
, addr
);
922 get_page(virt_to_page(pmd
));
925 kvm_set_pmd(pmd
, *new_pmd
);
929 static int stage2_set_pte(struct kvm
*kvm
, struct kvm_mmu_memory_cache
*cache
,
930 phys_addr_t addr
, const pte_t
*new_pte
,
935 bool iomap
= flags
& KVM_S2PTE_FLAG_IS_IOMAP
;
936 bool logging_active
= flags
& KVM_S2_FLAG_LOGGING_ACTIVE
;
938 VM_BUG_ON(logging_active
&& !cache
);
940 /* Create stage-2 page table mapping - Levels 0 and 1 */
941 pmd
= stage2_get_pmd(kvm
, cache
, addr
);
944 * Ignore calls from kvm_set_spte_hva for unallocated
951 * While dirty page logging - dissolve huge PMD, then continue on to
955 stage2_dissolve_pmd(kvm
, addr
, pmd
);
957 /* Create stage-2 page mappings - Level 2 */
958 if (pmd_none(*pmd
)) {
960 return 0; /* ignore calls from kvm_set_spte_hva */
961 pte
= mmu_memory_cache_alloc(cache
);
962 pmd_populate_kernel(NULL
, pmd
, pte
);
963 get_page(virt_to_page(pmd
));
966 pte
= pte_offset_kernel(pmd
, addr
);
968 if (iomap
&& pte_present(*pte
))
971 /* Create 2nd stage page table mapping - Level 3 */
973 if (pte_present(old_pte
)) {
974 kvm_set_pte(pte
, __pte(0));
975 kvm_tlb_flush_vmid_ipa(kvm
, addr
);
977 get_page(virt_to_page(pte
));
980 kvm_set_pte(pte
, *new_pte
);
984 #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
985 static int stage2_ptep_test_and_clear_young(pte_t
*pte
)
987 if (pte_young(*pte
)) {
988 *pte
= pte_mkold(*pte
);
994 static int stage2_ptep_test_and_clear_young(pte_t
*pte
)
996 return __ptep_test_and_clear_young(pte
);
1000 static int stage2_pmdp_test_and_clear_young(pmd_t
*pmd
)
1002 return stage2_ptep_test_and_clear_young((pte_t
*)pmd
);
1006 * kvm_phys_addr_ioremap - map a device range to guest IPA
1008 * @kvm: The KVM pointer
1009 * @guest_ipa: The IPA at which to insert the mapping
1010 * @pa: The physical address of the device
1011 * @size: The size of the mapping
1013 int kvm_phys_addr_ioremap(struct kvm
*kvm
, phys_addr_t guest_ipa
,
1014 phys_addr_t pa
, unsigned long size
, bool writable
)
1016 phys_addr_t addr
, end
;
1019 struct kvm_mmu_memory_cache cache
= { 0, };
1021 end
= (guest_ipa
+ size
+ PAGE_SIZE
- 1) & PAGE_MASK
;
1022 pfn
= __phys_to_pfn(pa
);
1024 for (addr
= guest_ipa
; addr
< end
; addr
+= PAGE_SIZE
) {
1025 pte_t pte
= pfn_pte(pfn
, PAGE_S2_DEVICE
);
1028 pte
= kvm_s2pte_mkwrite(pte
);
1030 ret
= mmu_topup_memory_cache(&cache
, KVM_MMU_CACHE_MIN_PAGES
,
1034 spin_lock(&kvm
->mmu_lock
);
1035 ret
= stage2_set_pte(kvm
, &cache
, addr
, &pte
,
1036 KVM_S2PTE_FLAG_IS_IOMAP
);
1037 spin_unlock(&kvm
->mmu_lock
);
1045 mmu_free_memory_cache(&cache
);
1049 static bool transparent_hugepage_adjust(kvm_pfn_t
*pfnp
, phys_addr_t
*ipap
)
1051 kvm_pfn_t pfn
= *pfnp
;
1052 gfn_t gfn
= *ipap
>> PAGE_SHIFT
;
1054 if (PageTransCompoundMap(pfn_to_page(pfn
))) {
1057 * The address we faulted on is backed by a transparent huge
1058 * page. However, because we map the compound huge page and
1059 * not the individual tail page, we need to transfer the
1060 * refcount to the head page. We have to be careful that the
1061 * THP doesn't start to split while we are adjusting the
1064 * We are sure this doesn't happen, because mmu_notifier_retry
1065 * was successful and we are holding the mmu_lock, so if this
1066 * THP is trying to split, it will be blocked in the mmu
1067 * notifier before touching any of the pages, specifically
1068 * before being able to call __split_huge_page_refcount().
1070 * We can therefore safely transfer the refcount from PG_tail
1071 * to PG_head and switch the pfn from a tail page to the head
1074 mask
= PTRS_PER_PMD
- 1;
1075 VM_BUG_ON((gfn
& mask
) != (pfn
& mask
));
1078 kvm_release_pfn_clean(pfn
);
1090 static bool kvm_is_write_fault(struct kvm_vcpu
*vcpu
)
1092 if (kvm_vcpu_trap_is_iabt(vcpu
))
1095 return kvm_vcpu_dabt_iswrite(vcpu
);
1099 * stage2_wp_ptes - write protect PMD range
1100 * @pmd: pointer to pmd entry
1101 * @addr: range start address
1102 * @end: range end address
1104 static void stage2_wp_ptes(pmd_t
*pmd
, phys_addr_t addr
, phys_addr_t end
)
1108 pte
= pte_offset_kernel(pmd
, addr
);
1110 if (!pte_none(*pte
)) {
1111 if (!kvm_s2pte_readonly(pte
))
1112 kvm_set_s2pte_readonly(pte
);
1114 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
1118 * stage2_wp_pmds - write protect PUD range
1119 * @pud: pointer to pud entry
1120 * @addr: range start address
1121 * @end: range end address
1123 static void stage2_wp_pmds(pud_t
*pud
, phys_addr_t addr
, phys_addr_t end
)
1128 pmd
= stage2_pmd_offset(pud
, addr
);
1131 next
= stage2_pmd_addr_end(addr
, end
);
1132 if (!pmd_none(*pmd
)) {
1133 if (pmd_thp_or_huge(*pmd
)) {
1134 if (!kvm_s2pmd_readonly(pmd
))
1135 kvm_set_s2pmd_readonly(pmd
);
1137 stage2_wp_ptes(pmd
, addr
, next
);
1140 } while (pmd
++, addr
= next
, addr
!= end
);
1144 * stage2_wp_puds - write protect PGD range
1145 * @pgd: pointer to pgd entry
1146 * @addr: range start address
1147 * @end: range end address
1149 * Process PUD entries, for a huge PUD we cause a panic.
1151 static void stage2_wp_puds(pgd_t
*pgd
, phys_addr_t addr
, phys_addr_t end
)
1156 pud
= stage2_pud_offset(pgd
, addr
);
1158 next
= stage2_pud_addr_end(addr
, end
);
1159 if (!stage2_pud_none(*pud
)) {
1160 /* TODO:PUD not supported, revisit later if supported */
1161 BUG_ON(stage2_pud_huge(*pud
));
1162 stage2_wp_pmds(pud
, addr
, next
);
1164 } while (pud
++, addr
= next
, addr
!= end
);
1168 * stage2_wp_range() - write protect stage2 memory region range
1169 * @kvm: The KVM pointer
1170 * @addr: Start address of range
1171 * @end: End address of range
1173 static void stage2_wp_range(struct kvm
*kvm
, phys_addr_t addr
, phys_addr_t end
)
1178 pgd
= kvm
->arch
.pgd
+ stage2_pgd_index(addr
);
1181 * Release kvm_mmu_lock periodically if the memory region is
1182 * large. Otherwise, we may see kernel panics with
1183 * CONFIG_DETECT_HUNG_TASK, CONFIG_LOCKUP_DETECTOR,
1184 * CONFIG_LOCKDEP. Additionally, holding the lock too long
1185 * will also starve other vCPUs. We have to also make sure
1186 * that the page tables are not freed while we released
1189 cond_resched_lock(&kvm
->mmu_lock
);
1190 if (!READ_ONCE(kvm
->arch
.pgd
))
1192 next
= stage2_pgd_addr_end(addr
, end
);
1193 if (stage2_pgd_present(*pgd
))
1194 stage2_wp_puds(pgd
, addr
, next
);
1195 } while (pgd
++, addr
= next
, addr
!= end
);
1199 * kvm_mmu_wp_memory_region() - write protect stage 2 entries for memory slot
1200 * @kvm: The KVM pointer
1201 * @slot: The memory slot to write protect
1203 * Called to start logging dirty pages after memory region
1204 * KVM_MEM_LOG_DIRTY_PAGES operation is called. After this function returns
1205 * all present PMD and PTEs are write protected in the memory region.
1206 * Afterwards read of dirty page log can be called.
1208 * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired,
1209 * serializing operations for VM memory regions.
1211 void kvm_mmu_wp_memory_region(struct kvm
*kvm
, int slot
)
1213 struct kvm_memslots
*slots
= kvm_memslots(kvm
);
1214 struct kvm_memory_slot
*memslot
= id_to_memslot(slots
, slot
);
1215 phys_addr_t start
= memslot
->base_gfn
<< PAGE_SHIFT
;
1216 phys_addr_t end
= (memslot
->base_gfn
+ memslot
->npages
) << PAGE_SHIFT
;
1218 spin_lock(&kvm
->mmu_lock
);
1219 stage2_wp_range(kvm
, start
, end
);
1220 spin_unlock(&kvm
->mmu_lock
);
1221 kvm_flush_remote_tlbs(kvm
);
1225 * kvm_mmu_write_protect_pt_masked() - write protect dirty pages
1226 * @kvm: The KVM pointer
1227 * @slot: The memory slot associated with mask
1228 * @gfn_offset: The gfn offset in memory slot
1229 * @mask: The mask of dirty pages at offset 'gfn_offset' in this memory
1230 * slot to be write protected
1232 * Walks bits set in mask write protects the associated pte's. Caller must
1233 * acquire kvm_mmu_lock.
1235 static void kvm_mmu_write_protect_pt_masked(struct kvm
*kvm
,
1236 struct kvm_memory_slot
*slot
,
1237 gfn_t gfn_offset
, unsigned long mask
)
1239 phys_addr_t base_gfn
= slot
->base_gfn
+ gfn_offset
;
1240 phys_addr_t start
= (base_gfn
+ __ffs(mask
)) << PAGE_SHIFT
;
1241 phys_addr_t end
= (base_gfn
+ __fls(mask
) + 1) << PAGE_SHIFT
;
1243 stage2_wp_range(kvm
, start
, end
);
1247 * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected
1250 * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to
1251 * enable dirty logging for them.
1253 void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm
*kvm
,
1254 struct kvm_memory_slot
*slot
,
1255 gfn_t gfn_offset
, unsigned long mask
)
1257 kvm_mmu_write_protect_pt_masked(kvm
, slot
, gfn_offset
, mask
);
1260 static void coherent_cache_guest_page(struct kvm_vcpu
*vcpu
, kvm_pfn_t pfn
,
1263 __coherent_cache_guest_page(vcpu
, pfn
, size
);
1266 static void kvm_send_hwpoison_signal(unsigned long address
,
1267 struct vm_area_struct
*vma
)
1271 info
.si_signo
= SIGBUS
;
1273 info
.si_code
= BUS_MCEERR_AR
;
1274 info
.si_addr
= (void __user
*)address
;
1276 if (is_vm_hugetlb_page(vma
))
1277 info
.si_addr_lsb
= huge_page_shift(hstate_vma(vma
));
1279 info
.si_addr_lsb
= PAGE_SHIFT
;
1281 send_sig_info(SIGBUS
, &info
, current
);
1284 static int user_mem_abort(struct kvm_vcpu
*vcpu
, phys_addr_t fault_ipa
,
1285 struct kvm_memory_slot
*memslot
, unsigned long hva
,
1286 unsigned long fault_status
)
1289 bool write_fault
, writable
, hugetlb
= false, force_pte
= false;
1290 unsigned long mmu_seq
;
1291 gfn_t gfn
= fault_ipa
>> PAGE_SHIFT
;
1292 struct kvm
*kvm
= vcpu
->kvm
;
1293 struct kvm_mmu_memory_cache
*memcache
= &vcpu
->arch
.mmu_page_cache
;
1294 struct vm_area_struct
*vma
;
1296 pgprot_t mem_type
= PAGE_S2
;
1297 bool logging_active
= memslot_is_logging(memslot
);
1298 unsigned long flags
= 0;
1300 write_fault
= kvm_is_write_fault(vcpu
);
1301 if (fault_status
== FSC_PERM
&& !write_fault
) {
1302 kvm_err("Unexpected L2 read permission error\n");
1306 /* Let's check if we will get back a huge page backed by hugetlbfs */
1307 down_read(¤t
->mm
->mmap_sem
);
1308 vma
= find_vma_intersection(current
->mm
, hva
, hva
+ 1);
1309 if (unlikely(!vma
)) {
1310 kvm_err("Failed to find VMA for hva 0x%lx\n", hva
);
1311 up_read(¤t
->mm
->mmap_sem
);
1315 if (is_vm_hugetlb_page(vma
) && !logging_active
) {
1317 gfn
= (fault_ipa
& PMD_MASK
) >> PAGE_SHIFT
;
1320 * Pages belonging to memslots that don't have the same
1321 * alignment for userspace and IPA cannot be mapped using
1322 * block descriptors even if the pages belong to a THP for
1323 * the process, because the stage-2 block descriptor will
1324 * cover more than a single THP and we loose atomicity for
1325 * unmapping, updates, and splits of the THP or other pages
1326 * in the stage-2 block range.
1328 if ((memslot
->userspace_addr
& ~PMD_MASK
) !=
1329 ((memslot
->base_gfn
<< PAGE_SHIFT
) & ~PMD_MASK
))
1332 up_read(¤t
->mm
->mmap_sem
);
1334 /* We need minimum second+third level pages */
1335 ret
= mmu_topup_memory_cache(memcache
, KVM_MMU_CACHE_MIN_PAGES
,
1340 mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
1342 * Ensure the read of mmu_notifier_seq happens before we call
1343 * gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk
1344 * the page we just got a reference to gets unmapped before we have a
1345 * chance to grab the mmu_lock, which ensure that if the page gets
1346 * unmapped afterwards, the call to kvm_unmap_hva will take it away
1347 * from us again properly. This smp_rmb() interacts with the smp_wmb()
1348 * in kvm_mmu_notifier_invalidate_<page|range_end>.
1352 pfn
= gfn_to_pfn_prot(kvm
, gfn
, write_fault
, &writable
);
1353 if (pfn
== KVM_PFN_ERR_HWPOISON
) {
1354 kvm_send_hwpoison_signal(hva
, vma
);
1357 if (is_error_noslot_pfn(pfn
))
1360 if (kvm_is_device_pfn(pfn
)) {
1361 mem_type
= PAGE_S2_DEVICE
;
1362 flags
|= KVM_S2PTE_FLAG_IS_IOMAP
;
1363 } else if (logging_active
) {
1365 * Faults on pages in a memslot with logging enabled
1366 * should not be mapped with huge pages (it introduces churn
1367 * and performance degradation), so force a pte mapping.
1370 flags
|= KVM_S2_FLAG_LOGGING_ACTIVE
;
1373 * Only actually map the page as writable if this was a write
1380 spin_lock(&kvm
->mmu_lock
);
1381 if (mmu_notifier_retry(kvm
, mmu_seq
))
1384 if (!hugetlb
&& !force_pte
)
1385 hugetlb
= transparent_hugepage_adjust(&pfn
, &fault_ipa
);
1388 pmd_t new_pmd
= pfn_pmd(pfn
, mem_type
);
1389 new_pmd
= pmd_mkhuge(new_pmd
);
1391 new_pmd
= kvm_s2pmd_mkwrite(new_pmd
);
1392 kvm_set_pfn_dirty(pfn
);
1394 coherent_cache_guest_page(vcpu
, pfn
, PMD_SIZE
);
1395 ret
= stage2_set_pmd_huge(kvm
, memcache
, fault_ipa
, &new_pmd
);
1397 pte_t new_pte
= pfn_pte(pfn
, mem_type
);
1400 new_pte
= kvm_s2pte_mkwrite(new_pte
);
1401 kvm_set_pfn_dirty(pfn
);
1402 mark_page_dirty(kvm
, gfn
);
1404 coherent_cache_guest_page(vcpu
, pfn
, PAGE_SIZE
);
1405 ret
= stage2_set_pte(kvm
, memcache
, fault_ipa
, &new_pte
, flags
);
1409 spin_unlock(&kvm
->mmu_lock
);
1410 kvm_set_pfn_accessed(pfn
);
1411 kvm_release_pfn_clean(pfn
);
1416 * Resolve the access fault by making the page young again.
1417 * Note that because the faulting entry is guaranteed not to be
1418 * cached in the TLB, we don't need to invalidate anything.
1419 * Only the HW Access Flag updates are supported for Stage 2 (no DBM),
1420 * so there is no need for atomic (pte|pmd)_mkyoung operations.
1422 static void handle_access_fault(struct kvm_vcpu
*vcpu
, phys_addr_t fault_ipa
)
1427 bool pfn_valid
= false;
1429 trace_kvm_access_fault(fault_ipa
);
1431 spin_lock(&vcpu
->kvm
->mmu_lock
);
1433 pmd
= stage2_get_pmd(vcpu
->kvm
, NULL
, fault_ipa
);
1434 if (!pmd
|| pmd_none(*pmd
)) /* Nothing there */
1437 if (pmd_thp_or_huge(*pmd
)) { /* THP, HugeTLB */
1438 *pmd
= pmd_mkyoung(*pmd
);
1439 pfn
= pmd_pfn(*pmd
);
1444 pte
= pte_offset_kernel(pmd
, fault_ipa
);
1445 if (pte_none(*pte
)) /* Nothing there either */
1448 *pte
= pte_mkyoung(*pte
); /* Just a page... */
1449 pfn
= pte_pfn(*pte
);
1452 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1454 kvm_set_pfn_accessed(pfn
);
1457 static bool is_abort_sea(unsigned long fault_status
)
1459 switch (fault_status
) {
1477 * kvm_handle_guest_abort - handles all 2nd stage aborts
1478 * @vcpu: the VCPU pointer
1479 * @run: the kvm_run structure
1481 * Any abort that gets to the host is almost guaranteed to be caused by a
1482 * missing second stage translation table entry, which can mean that either the
1483 * guest simply needs more memory and we must allocate an appropriate page or it
1484 * can mean that the guest tried to access I/O memory, which is emulated by user
1485 * space. The distinction is based on the IPA causing the fault and whether this
1486 * memory region has been registered as standard RAM by user space.
1488 int kvm_handle_guest_abort(struct kvm_vcpu
*vcpu
, struct kvm_run
*run
)
1490 unsigned long fault_status
;
1491 phys_addr_t fault_ipa
;
1492 struct kvm_memory_slot
*memslot
;
1494 bool is_iabt
, write_fault
, writable
;
1498 fault_status
= kvm_vcpu_trap_get_fault_type(vcpu
);
1500 fault_ipa
= kvm_vcpu_get_fault_ipa(vcpu
);
1503 * The host kernel will handle the synchronous external abort. There
1504 * is no need to pass the error into the guest.
1506 if (is_abort_sea(fault_status
)) {
1507 if (!handle_guest_sea(fault_ipa
, kvm_vcpu_get_hsr(vcpu
)))
1511 is_iabt
= kvm_vcpu_trap_is_iabt(vcpu
);
1512 if (unlikely(!is_iabt
&& kvm_vcpu_dabt_isextabt(vcpu
))) {
1513 kvm_inject_vabt(vcpu
);
1517 trace_kvm_guest_fault(*vcpu_pc(vcpu
), kvm_vcpu_get_hsr(vcpu
),
1518 kvm_vcpu_get_hfar(vcpu
), fault_ipa
);
1520 /* Check the stage-2 fault is trans. fault or write fault */
1521 if (fault_status
!= FSC_FAULT
&& fault_status
!= FSC_PERM
&&
1522 fault_status
!= FSC_ACCESS
) {
1523 kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n",
1524 kvm_vcpu_trap_get_class(vcpu
),
1525 (unsigned long)kvm_vcpu_trap_get_fault(vcpu
),
1526 (unsigned long)kvm_vcpu_get_hsr(vcpu
));
1530 idx
= srcu_read_lock(&vcpu
->kvm
->srcu
);
1532 gfn
= fault_ipa
>> PAGE_SHIFT
;
1533 memslot
= gfn_to_memslot(vcpu
->kvm
, gfn
);
1534 hva
= gfn_to_hva_memslot_prot(memslot
, gfn
, &writable
);
1535 write_fault
= kvm_is_write_fault(vcpu
);
1536 if (kvm_is_error_hva(hva
) || (write_fault
&& !writable
)) {
1538 /* Prefetch Abort on I/O address */
1539 kvm_inject_pabt(vcpu
, kvm_vcpu_get_hfar(vcpu
));
1545 * Check for a cache maintenance operation. Since we
1546 * ended-up here, we know it is outside of any memory
1547 * slot. But we can't find out if that is for a device,
1548 * or if the guest is just being stupid. The only thing
1549 * we know for sure is that this range cannot be cached.
1551 * So let's assume that the guest is just being
1552 * cautious, and skip the instruction.
1554 if (kvm_vcpu_dabt_is_cm(vcpu
)) {
1555 kvm_skip_instr(vcpu
, kvm_vcpu_trap_il_is32bit(vcpu
));
1561 * The IPA is reported as [MAX:12], so we need to
1562 * complement it with the bottom 12 bits from the
1563 * faulting VA. This is always 12 bits, irrespective
1566 fault_ipa
|= kvm_vcpu_get_hfar(vcpu
) & ((1 << 12) - 1);
1567 ret
= io_mem_abort(vcpu
, run
, fault_ipa
);
1571 /* Userspace should not be able to register out-of-bounds IPAs */
1572 VM_BUG_ON(fault_ipa
>= KVM_PHYS_SIZE
);
1574 if (fault_status
== FSC_ACCESS
) {
1575 handle_access_fault(vcpu
, fault_ipa
);
1580 ret
= user_mem_abort(vcpu
, fault_ipa
, memslot
, hva
, fault_status
);
1584 srcu_read_unlock(&vcpu
->kvm
->srcu
, idx
);
1588 static int handle_hva_to_gpa(struct kvm
*kvm
,
1589 unsigned long start
,
1591 int (*handler
)(struct kvm
*kvm
,
1592 gpa_t gpa
, u64 size
,
1596 struct kvm_memslots
*slots
;
1597 struct kvm_memory_slot
*memslot
;
1600 slots
= kvm_memslots(kvm
);
1602 /* we only care about the pages that the guest sees */
1603 kvm_for_each_memslot(memslot
, slots
) {
1604 unsigned long hva_start
, hva_end
;
1607 hva_start
= max(start
, memslot
->userspace_addr
);
1608 hva_end
= min(end
, memslot
->userspace_addr
+
1609 (memslot
->npages
<< PAGE_SHIFT
));
1610 if (hva_start
>= hva_end
)
1613 gpa
= hva_to_gfn_memslot(hva_start
, memslot
) << PAGE_SHIFT
;
1614 ret
|= handler(kvm
, gpa
, (u64
)(hva_end
- hva_start
), data
);
1620 static int kvm_unmap_hva_handler(struct kvm
*kvm
, gpa_t gpa
, u64 size
, void *data
)
1622 unmap_stage2_range(kvm
, gpa
, size
);
1626 int kvm_unmap_hva(struct kvm
*kvm
, unsigned long hva
)
1628 unsigned long end
= hva
+ PAGE_SIZE
;
1633 trace_kvm_unmap_hva(hva
);
1634 handle_hva_to_gpa(kvm
, hva
, end
, &kvm_unmap_hva_handler
, NULL
);
1638 int kvm_unmap_hva_range(struct kvm
*kvm
,
1639 unsigned long start
, unsigned long end
)
1644 trace_kvm_unmap_hva_range(start
, end
);
1645 handle_hva_to_gpa(kvm
, start
, end
, &kvm_unmap_hva_handler
, NULL
);
1649 static int kvm_set_spte_handler(struct kvm
*kvm
, gpa_t gpa
, u64 size
, void *data
)
1651 pte_t
*pte
= (pte_t
*)data
;
1653 WARN_ON(size
!= PAGE_SIZE
);
1655 * We can always call stage2_set_pte with KVM_S2PTE_FLAG_LOGGING_ACTIVE
1656 * flag clear because MMU notifiers will have unmapped a huge PMD before
1657 * calling ->change_pte() (which in turn calls kvm_set_spte_hva()) and
1658 * therefore stage2_set_pte() never needs to clear out a huge PMD
1659 * through this calling path.
1661 stage2_set_pte(kvm
, NULL
, gpa
, pte
, 0);
1666 void kvm_set_spte_hva(struct kvm
*kvm
, unsigned long hva
, pte_t pte
)
1668 unsigned long end
= hva
+ PAGE_SIZE
;
1674 trace_kvm_set_spte_hva(hva
);
1675 stage2_pte
= pfn_pte(pte_pfn(pte
), PAGE_S2
);
1676 handle_hva_to_gpa(kvm
, hva
, end
, &kvm_set_spte_handler
, &stage2_pte
);
1679 static int kvm_age_hva_handler(struct kvm
*kvm
, gpa_t gpa
, u64 size
, void *data
)
1684 WARN_ON(size
!= PAGE_SIZE
&& size
!= PMD_SIZE
);
1685 pmd
= stage2_get_pmd(kvm
, NULL
, gpa
);
1686 if (!pmd
|| pmd_none(*pmd
)) /* Nothing there */
1689 if (pmd_thp_or_huge(*pmd
)) /* THP, HugeTLB */
1690 return stage2_pmdp_test_and_clear_young(pmd
);
1692 pte
= pte_offset_kernel(pmd
, gpa
);
1696 return stage2_ptep_test_and_clear_young(pte
);
1699 static int kvm_test_age_hva_handler(struct kvm
*kvm
, gpa_t gpa
, u64 size
, void *data
)
1704 WARN_ON(size
!= PAGE_SIZE
&& size
!= PMD_SIZE
);
1705 pmd
= stage2_get_pmd(kvm
, NULL
, gpa
);
1706 if (!pmd
|| pmd_none(*pmd
)) /* Nothing there */
1709 if (pmd_thp_or_huge(*pmd
)) /* THP, HugeTLB */
1710 return pmd_young(*pmd
);
1712 pte
= pte_offset_kernel(pmd
, gpa
);
1713 if (!pte_none(*pte
)) /* Just a page... */
1714 return pte_young(*pte
);
1719 int kvm_age_hva(struct kvm
*kvm
, unsigned long start
, unsigned long end
)
1723 trace_kvm_age_hva(start
, end
);
1724 return handle_hva_to_gpa(kvm
, start
, end
, kvm_age_hva_handler
, NULL
);
1727 int kvm_test_age_hva(struct kvm
*kvm
, unsigned long hva
)
1731 trace_kvm_test_age_hva(hva
);
1732 return handle_hva_to_gpa(kvm
, hva
, hva
, kvm_test_age_hva_handler
, NULL
);
1735 void kvm_mmu_free_memory_caches(struct kvm_vcpu
*vcpu
)
1737 mmu_free_memory_cache(&vcpu
->arch
.mmu_page_cache
);
1740 phys_addr_t
kvm_mmu_get_httbr(void)
1742 if (__kvm_cpu_uses_extended_idmap())
1743 return virt_to_phys(merged_hyp_pgd
);
1745 return virt_to_phys(hyp_pgd
);
1748 phys_addr_t
kvm_get_idmap_vector(void)
1750 return hyp_idmap_vector
;
1753 static int kvm_map_idmap_text(pgd_t
*pgd
)
1757 /* Create the idmap in the boot page tables */
1758 err
= __create_hyp_mappings(pgd
,
1759 hyp_idmap_start
, hyp_idmap_end
,
1760 __phys_to_pfn(hyp_idmap_start
),
1763 kvm_err("Failed to idmap %lx-%lx\n",
1764 hyp_idmap_start
, hyp_idmap_end
);
1769 int kvm_mmu_init(void)
1773 hyp_idmap_start
= kvm_virt_to_phys(__hyp_idmap_text_start
);
1774 hyp_idmap_end
= kvm_virt_to_phys(__hyp_idmap_text_end
);
1775 hyp_idmap_vector
= kvm_virt_to_phys(__kvm_hyp_init
);
1778 * We rely on the linker script to ensure at build time that the HYP
1779 * init code does not cross a page boundary.
1781 BUG_ON((hyp_idmap_start
^ (hyp_idmap_end
- 1)) & PAGE_MASK
);
1783 kvm_info("IDMAP page: %lx\n", hyp_idmap_start
);
1784 kvm_info("HYP VA range: %lx:%lx\n",
1785 kern_hyp_va(PAGE_OFFSET
), kern_hyp_va(~0UL));
1787 if (hyp_idmap_start
>= kern_hyp_va(PAGE_OFFSET
) &&
1788 hyp_idmap_start
< kern_hyp_va(~0UL) &&
1789 hyp_idmap_start
!= (unsigned long)__hyp_idmap_text_start
) {
1791 * The idmap page is intersecting with the VA space,
1792 * it is not safe to continue further.
1794 kvm_err("IDMAP intersecting with HYP VA, unable to continue\n");
1799 hyp_pgd
= (pgd_t
*)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
, hyp_pgd_order
);
1801 kvm_err("Hyp mode PGD not allocated\n");
1806 if (__kvm_cpu_uses_extended_idmap()) {
1807 boot_hyp_pgd
= (pgd_t
*)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
,
1809 if (!boot_hyp_pgd
) {
1810 kvm_err("Hyp boot PGD not allocated\n");
1815 err
= kvm_map_idmap_text(boot_hyp_pgd
);
1819 merged_hyp_pgd
= (pgd_t
*)__get_free_page(GFP_KERNEL
| __GFP_ZERO
);
1820 if (!merged_hyp_pgd
) {
1821 kvm_err("Failed to allocate extra HYP pgd\n");
1824 __kvm_extend_hypmap(boot_hyp_pgd
, hyp_pgd
, merged_hyp_pgd
,
1827 err
= kvm_map_idmap_text(hyp_pgd
);
1838 void kvm_arch_commit_memory_region(struct kvm
*kvm
,
1839 const struct kvm_userspace_memory_region
*mem
,
1840 const struct kvm_memory_slot
*old
,
1841 const struct kvm_memory_slot
*new,
1842 enum kvm_mr_change change
)
1845 * At this point memslot has been committed and there is an
1846 * allocated dirty_bitmap[], dirty pages will be be tracked while the
1847 * memory slot is write protected.
1849 if (change
!= KVM_MR_DELETE
&& mem
->flags
& KVM_MEM_LOG_DIRTY_PAGES
)
1850 kvm_mmu_wp_memory_region(kvm
, mem
->slot
);
1853 int kvm_arch_prepare_memory_region(struct kvm
*kvm
,
1854 struct kvm_memory_slot
*memslot
,
1855 const struct kvm_userspace_memory_region
*mem
,
1856 enum kvm_mr_change change
)
1858 hva_t hva
= mem
->userspace_addr
;
1859 hva_t reg_end
= hva
+ mem
->memory_size
;
1860 bool writable
= !(mem
->flags
& KVM_MEM_READONLY
);
1863 if (change
!= KVM_MR_CREATE
&& change
!= KVM_MR_MOVE
&&
1864 change
!= KVM_MR_FLAGS_ONLY
)
1868 * Prevent userspace from creating a memory region outside of the IPA
1869 * space addressable by the KVM guest IPA space.
1871 if (memslot
->base_gfn
+ memslot
->npages
>=
1872 (KVM_PHYS_SIZE
>> PAGE_SHIFT
))
1875 down_read(¤t
->mm
->mmap_sem
);
1877 * A memory region could potentially cover multiple VMAs, and any holes
1878 * between them, so iterate over all of them to find out if we can map
1879 * any of them right now.
1881 * +--------------------------------------------+
1882 * +---------------+----------------+ +----------------+
1883 * | : VMA 1 | VMA 2 | | VMA 3 : |
1884 * +---------------+----------------+ +----------------+
1886 * +--------------------------------------------+
1889 struct vm_area_struct
*vma
= find_vma(current
->mm
, hva
);
1890 hva_t vm_start
, vm_end
;
1892 if (!vma
|| vma
->vm_start
>= reg_end
)
1896 * Mapping a read-only VMA is only allowed if the
1897 * memory region is configured as read-only.
1899 if (writable
&& !(vma
->vm_flags
& VM_WRITE
)) {
1905 * Take the intersection of this VMA with the memory region
1907 vm_start
= max(hva
, vma
->vm_start
);
1908 vm_end
= min(reg_end
, vma
->vm_end
);
1910 if (vma
->vm_flags
& VM_PFNMAP
) {
1911 gpa_t gpa
= mem
->guest_phys_addr
+
1912 (vm_start
- mem
->userspace_addr
);
1915 pa
= (phys_addr_t
)vma
->vm_pgoff
<< PAGE_SHIFT
;
1916 pa
+= vm_start
- vma
->vm_start
;
1918 /* IO region dirty page logging not allowed */
1919 if (memslot
->flags
& KVM_MEM_LOG_DIRTY_PAGES
) {
1924 ret
= kvm_phys_addr_ioremap(kvm
, gpa
, pa
,
1931 } while (hva
< reg_end
);
1933 if (change
== KVM_MR_FLAGS_ONLY
)
1936 spin_lock(&kvm
->mmu_lock
);
1938 unmap_stage2_range(kvm
, mem
->guest_phys_addr
, mem
->memory_size
);
1940 stage2_flush_memslot(kvm
, memslot
);
1941 spin_unlock(&kvm
->mmu_lock
);
1943 up_read(¤t
->mm
->mmap_sem
);
1947 void kvm_arch_free_memslot(struct kvm
*kvm
, struct kvm_memory_slot
*free
,
1948 struct kvm_memory_slot
*dont
)
1952 int kvm_arch_create_memslot(struct kvm
*kvm
, struct kvm_memory_slot
*slot
,
1953 unsigned long npages
)
1958 void kvm_arch_memslots_updated(struct kvm
*kvm
, struct kvm_memslots
*slots
)
1962 void kvm_arch_flush_shadow_all(struct kvm
*kvm
)
1964 kvm_free_stage2_pgd(kvm
);
1967 void kvm_arch_flush_shadow_memslot(struct kvm
*kvm
,
1968 struct kvm_memory_slot
*slot
)
1970 gpa_t gpa
= slot
->base_gfn
<< PAGE_SHIFT
;
1971 phys_addr_t size
= slot
->npages
<< PAGE_SHIFT
;
1973 spin_lock(&kvm
->mmu_lock
);
1974 unmap_stage2_range(kvm
, gpa
, size
);
1975 spin_unlock(&kvm
->mmu_lock
);
1979 * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
1982 * - S/W ops are local to a CPU (not broadcast)
1983 * - We have line migration behind our back (speculation)
1984 * - System caches don't support S/W at all (damn!)
1986 * In the face of the above, the best we can do is to try and convert
1987 * S/W ops to VA ops. Because the guest is not allowed to infer the
1988 * S/W to PA mapping, it can only use S/W to nuke the whole cache,
1989 * which is a rather good thing for us.
1991 * Also, it is only used when turning caches on/off ("The expected
1992 * usage of the cache maintenance instructions that operate by set/way
1993 * is associated with the cache maintenance instructions associated
1994 * with the powerdown and powerup of caches, if this is required by
1995 * the implementation.").
1997 * We use the following policy:
1999 * - If we trap a S/W operation, we enable VM trapping to detect
2000 * caches being turned on/off, and do a full clean.
2002 * - We flush the caches on both caches being turned on and off.
2004 * - Once the caches are enabled, we stop trapping VM ops.
2006 void kvm_set_way_flush(struct kvm_vcpu
*vcpu
)
2008 unsigned long hcr
= vcpu_get_hcr(vcpu
);
2011 * If this is the first time we do a S/W operation
2012 * (i.e. HCR_TVM not set) flush the whole memory, and set the
2015 * Otherwise, rely on the VM trapping to wait for the MMU +
2016 * Caches to be turned off. At that point, we'll be able to
2017 * clean the caches again.
2019 if (!(hcr
& HCR_TVM
)) {
2020 trace_kvm_set_way_flush(*vcpu_pc(vcpu
),
2021 vcpu_has_cache_enabled(vcpu
));
2022 stage2_flush_vm(vcpu
->kvm
);
2023 vcpu_set_hcr(vcpu
, hcr
| HCR_TVM
);
2027 void kvm_toggle_cache(struct kvm_vcpu
*vcpu
, bool was_enabled
)
2029 bool now_enabled
= vcpu_has_cache_enabled(vcpu
);
2032 * If switching the MMU+caches on, need to invalidate the caches.
2033 * If switching it off, need to clean the caches.
2034 * Clean + invalidate does the trick always.
2036 if (now_enabled
!= was_enabled
)
2037 stage2_flush_vm(vcpu
->kvm
);
2039 /* Caches are now on, stop trapping VM ops (until a S/W op) */
2041 vcpu_set_hcr(vcpu
, vcpu_get_hcr(vcpu
) & ~HCR_TVM
);
2043 trace_kvm_toggle_cache(*vcpu_pc(vcpu
), was_enabled
, now_enabled
);