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 <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>
35 static pgd_t
*boot_hyp_pgd
;
36 static pgd_t
*hyp_pgd
;
37 static pgd_t
*merged_hyp_pgd
;
38 static DEFINE_MUTEX(kvm_hyp_pgd_mutex
);
40 static unsigned long hyp_idmap_start
;
41 static unsigned long hyp_idmap_end
;
42 static phys_addr_t hyp_idmap_vector
;
44 #define S2_PGD_SIZE (PTRS_PER_S2_PGD * sizeof(pgd_t))
45 #define hyp_pgd_order get_order(PTRS_PER_PGD * sizeof(pgd_t))
47 #define KVM_S2PTE_FLAG_IS_IOMAP (1UL << 0)
48 #define KVM_S2_FLAG_LOGGING_ACTIVE (1UL << 1)
50 static bool memslot_is_logging(struct kvm_memory_slot
*memslot
)
52 return memslot
->dirty_bitmap
&& !(memslot
->flags
& KVM_MEM_READONLY
);
56 * kvm_flush_remote_tlbs() - flush all VM TLB entries for v7/8
57 * @kvm: pointer to kvm structure.
59 * Interface to HYP function to flush all VM TLB entries
61 void kvm_flush_remote_tlbs(struct kvm
*kvm
)
63 kvm_call_hyp(__kvm_tlb_flush_vmid
, kvm
);
66 static void kvm_tlb_flush_vmid_ipa(struct kvm
*kvm
, phys_addr_t ipa
)
68 kvm_call_hyp(__kvm_tlb_flush_vmid_ipa
, kvm
, ipa
);
72 * D-Cache management functions. They take the page table entries by
73 * value, as they are flushing the cache using the kernel mapping (or
76 static void kvm_flush_dcache_pte(pte_t pte
)
78 __kvm_flush_dcache_pte(pte
);
81 static void kvm_flush_dcache_pmd(pmd_t pmd
)
83 __kvm_flush_dcache_pmd(pmd
);
86 static void kvm_flush_dcache_pud(pud_t pud
)
88 __kvm_flush_dcache_pud(pud
);
91 static bool kvm_is_device_pfn(unsigned long pfn
)
93 return !pfn_valid(pfn
);
97 * stage2_dissolve_pmd() - clear and flush huge PMD entry
98 * @kvm: pointer to kvm structure.
100 * @pmd: pmd pointer for IPA
102 * Function clears a PMD entry, flushes addr 1st and 2nd stage TLBs. Marks all
103 * pages in the range dirty.
105 static void stage2_dissolve_pmd(struct kvm
*kvm
, phys_addr_t addr
, pmd_t
*pmd
)
107 if (!pmd_thp_or_huge(*pmd
))
111 kvm_tlb_flush_vmid_ipa(kvm
, addr
);
112 put_page(virt_to_page(pmd
));
115 static int mmu_topup_memory_cache(struct kvm_mmu_memory_cache
*cache
,
120 BUG_ON(max
> KVM_NR_MEM_OBJS
);
121 if (cache
->nobjs
>= min
)
123 while (cache
->nobjs
< max
) {
124 page
= (void *)__get_free_page(PGALLOC_GFP
);
127 cache
->objects
[cache
->nobjs
++] = page
;
132 static void mmu_free_memory_cache(struct kvm_mmu_memory_cache
*mc
)
135 free_page((unsigned long)mc
->objects
[--mc
->nobjs
]);
138 static void *mmu_memory_cache_alloc(struct kvm_mmu_memory_cache
*mc
)
142 BUG_ON(!mc
|| !mc
->nobjs
);
143 p
= mc
->objects
[--mc
->nobjs
];
147 static void clear_stage2_pgd_entry(struct kvm
*kvm
, pgd_t
*pgd
, phys_addr_t addr
)
149 pud_t
*pud_table __maybe_unused
= stage2_pud_offset(pgd
, 0UL);
150 stage2_pgd_clear(pgd
);
151 kvm_tlb_flush_vmid_ipa(kvm
, addr
);
152 stage2_pud_free(pud_table
);
153 put_page(virt_to_page(pgd
));
156 static void clear_stage2_pud_entry(struct kvm
*kvm
, pud_t
*pud
, phys_addr_t addr
)
158 pmd_t
*pmd_table __maybe_unused
= stage2_pmd_offset(pud
, 0);
159 VM_BUG_ON(stage2_pud_huge(*pud
));
160 stage2_pud_clear(pud
);
161 kvm_tlb_flush_vmid_ipa(kvm
, addr
);
162 stage2_pmd_free(pmd_table
);
163 put_page(virt_to_page(pud
));
166 static void clear_stage2_pmd_entry(struct kvm
*kvm
, pmd_t
*pmd
, phys_addr_t addr
)
168 pte_t
*pte_table
= pte_offset_kernel(pmd
, 0);
169 VM_BUG_ON(pmd_thp_or_huge(*pmd
));
171 kvm_tlb_flush_vmid_ipa(kvm
, addr
);
172 pte_free_kernel(NULL
, pte_table
);
173 put_page(virt_to_page(pmd
));
177 * Unmapping vs dcache management:
179 * If a guest maps certain memory pages as uncached, all writes will
180 * bypass the data cache and go directly to RAM. However, the CPUs
181 * can still speculate reads (not writes) and fill cache lines with
184 * Those cache lines will be *clean* cache lines though, so a
185 * clean+invalidate operation is equivalent to an invalidate
186 * operation, because no cache lines are marked dirty.
188 * Those clean cache lines could be filled prior to an uncached write
189 * by the guest, and the cache coherent IO subsystem would therefore
190 * end up writing old data to disk.
192 * This is why right after unmapping a page/section and invalidating
193 * the corresponding TLBs, we call kvm_flush_dcache_p*() to make sure
194 * the IO subsystem will never hit in the cache.
196 static void unmap_stage2_ptes(struct kvm
*kvm
, pmd_t
*pmd
,
197 phys_addr_t addr
, phys_addr_t end
)
199 phys_addr_t start_addr
= addr
;
200 pte_t
*pte
, *start_pte
;
202 start_pte
= pte
= pte_offset_kernel(pmd
, addr
);
204 if (!pte_none(*pte
)) {
205 pte_t old_pte
= *pte
;
207 kvm_set_pte(pte
, __pte(0));
208 kvm_tlb_flush_vmid_ipa(kvm
, addr
);
210 /* No need to invalidate the cache for device mappings */
211 if (!kvm_is_device_pfn(pte_pfn(old_pte
)))
212 kvm_flush_dcache_pte(old_pte
);
214 put_page(virt_to_page(pte
));
216 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
218 if (stage2_pte_table_empty(start_pte
))
219 clear_stage2_pmd_entry(kvm
, pmd
, start_addr
);
222 static void unmap_stage2_pmds(struct kvm
*kvm
, pud_t
*pud
,
223 phys_addr_t addr
, phys_addr_t end
)
225 phys_addr_t next
, start_addr
= addr
;
226 pmd_t
*pmd
, *start_pmd
;
228 start_pmd
= pmd
= stage2_pmd_offset(pud
, addr
);
230 next
= stage2_pmd_addr_end(addr
, end
);
231 if (!pmd_none(*pmd
)) {
232 if (pmd_thp_or_huge(*pmd
)) {
233 pmd_t old_pmd
= *pmd
;
236 kvm_tlb_flush_vmid_ipa(kvm
, addr
);
238 kvm_flush_dcache_pmd(old_pmd
);
240 put_page(virt_to_page(pmd
));
242 unmap_stage2_ptes(kvm
, pmd
, addr
, next
);
245 } while (pmd
++, addr
= next
, addr
!= end
);
247 if (stage2_pmd_table_empty(start_pmd
))
248 clear_stage2_pud_entry(kvm
, pud
, start_addr
);
251 static void unmap_stage2_puds(struct kvm
*kvm
, pgd_t
*pgd
,
252 phys_addr_t addr
, phys_addr_t end
)
254 phys_addr_t next
, start_addr
= addr
;
255 pud_t
*pud
, *start_pud
;
257 start_pud
= pud
= stage2_pud_offset(pgd
, addr
);
259 next
= stage2_pud_addr_end(addr
, end
);
260 if (!stage2_pud_none(*pud
)) {
261 if (stage2_pud_huge(*pud
)) {
262 pud_t old_pud
= *pud
;
264 stage2_pud_clear(pud
);
265 kvm_tlb_flush_vmid_ipa(kvm
, addr
);
266 kvm_flush_dcache_pud(old_pud
);
267 put_page(virt_to_page(pud
));
269 unmap_stage2_pmds(kvm
, pud
, addr
, next
);
272 } while (pud
++, addr
= next
, addr
!= end
);
274 if (stage2_pud_table_empty(start_pud
))
275 clear_stage2_pgd_entry(kvm
, pgd
, start_addr
);
279 * unmap_stage2_range -- Clear stage2 page table entries to unmap a range
280 * @kvm: The VM pointer
281 * @start: The intermediate physical base address of the range to unmap
282 * @size: The size of the area to unmap
284 * Clear a range of stage-2 mappings, lowering the various ref-counts. Must
285 * be called while holding mmu_lock (unless for freeing the stage2 pgd before
286 * destroying the VM), otherwise another faulting VCPU may come in and mess
287 * with things behind our backs.
289 static void unmap_stage2_range(struct kvm
*kvm
, phys_addr_t start
, u64 size
)
292 phys_addr_t addr
= start
, end
= start
+ size
;
295 assert_spin_locked(&kvm
->mmu_lock
);
296 pgd
= kvm
->arch
.pgd
+ stage2_pgd_index(addr
);
298 next
= stage2_pgd_addr_end(addr
, end
);
299 if (!stage2_pgd_none(*pgd
))
300 unmap_stage2_puds(kvm
, pgd
, addr
, next
);
302 * If the range is too large, release the kvm->mmu_lock
303 * to prevent starvation and lockup detector warnings.
306 cond_resched_lock(&kvm
->mmu_lock
);
307 } while (pgd
++, addr
= next
, addr
!= end
);
310 static void stage2_flush_ptes(struct kvm
*kvm
, pmd_t
*pmd
,
311 phys_addr_t addr
, phys_addr_t end
)
315 pte
= pte_offset_kernel(pmd
, addr
);
317 if (!pte_none(*pte
) && !kvm_is_device_pfn(pte_pfn(*pte
)))
318 kvm_flush_dcache_pte(*pte
);
319 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
322 static void stage2_flush_pmds(struct kvm
*kvm
, pud_t
*pud
,
323 phys_addr_t addr
, phys_addr_t end
)
328 pmd
= stage2_pmd_offset(pud
, addr
);
330 next
= stage2_pmd_addr_end(addr
, end
);
331 if (!pmd_none(*pmd
)) {
332 if (pmd_thp_or_huge(*pmd
))
333 kvm_flush_dcache_pmd(*pmd
);
335 stage2_flush_ptes(kvm
, pmd
, addr
, next
);
337 } while (pmd
++, addr
= next
, addr
!= end
);
340 static void stage2_flush_puds(struct kvm
*kvm
, pgd_t
*pgd
,
341 phys_addr_t addr
, phys_addr_t end
)
346 pud
= stage2_pud_offset(pgd
, addr
);
348 next
= stage2_pud_addr_end(addr
, end
);
349 if (!stage2_pud_none(*pud
)) {
350 if (stage2_pud_huge(*pud
))
351 kvm_flush_dcache_pud(*pud
);
353 stage2_flush_pmds(kvm
, pud
, addr
, next
);
355 } while (pud
++, addr
= next
, addr
!= end
);
358 static void stage2_flush_memslot(struct kvm
*kvm
,
359 struct kvm_memory_slot
*memslot
)
361 phys_addr_t addr
= memslot
->base_gfn
<< PAGE_SHIFT
;
362 phys_addr_t end
= addr
+ PAGE_SIZE
* memslot
->npages
;
366 pgd
= kvm
->arch
.pgd
+ stage2_pgd_index(addr
);
368 next
= stage2_pgd_addr_end(addr
, end
);
369 stage2_flush_puds(kvm
, pgd
, addr
, next
);
370 } while (pgd
++, addr
= next
, addr
!= end
);
374 * stage2_flush_vm - Invalidate cache for pages mapped in stage 2
375 * @kvm: The struct kvm pointer
377 * Go through the stage 2 page tables and invalidate any cache lines
378 * backing memory already mapped to the VM.
380 static void stage2_flush_vm(struct kvm
*kvm
)
382 struct kvm_memslots
*slots
;
383 struct kvm_memory_slot
*memslot
;
386 idx
= srcu_read_lock(&kvm
->srcu
);
387 spin_lock(&kvm
->mmu_lock
);
389 slots
= kvm_memslots(kvm
);
390 kvm_for_each_memslot(memslot
, slots
)
391 stage2_flush_memslot(kvm
, memslot
);
393 spin_unlock(&kvm
->mmu_lock
);
394 srcu_read_unlock(&kvm
->srcu
, idx
);
397 static void clear_hyp_pgd_entry(pgd_t
*pgd
)
399 pud_t
*pud_table __maybe_unused
= pud_offset(pgd
, 0UL);
401 pud_free(NULL
, pud_table
);
402 put_page(virt_to_page(pgd
));
405 static void clear_hyp_pud_entry(pud_t
*pud
)
407 pmd_t
*pmd_table __maybe_unused
= pmd_offset(pud
, 0);
408 VM_BUG_ON(pud_huge(*pud
));
410 pmd_free(NULL
, pmd_table
);
411 put_page(virt_to_page(pud
));
414 static void clear_hyp_pmd_entry(pmd_t
*pmd
)
416 pte_t
*pte_table
= pte_offset_kernel(pmd
, 0);
417 VM_BUG_ON(pmd_thp_or_huge(*pmd
));
419 pte_free_kernel(NULL
, pte_table
);
420 put_page(virt_to_page(pmd
));
423 static void unmap_hyp_ptes(pmd_t
*pmd
, phys_addr_t addr
, phys_addr_t end
)
425 pte_t
*pte
, *start_pte
;
427 start_pte
= pte
= pte_offset_kernel(pmd
, addr
);
429 if (!pte_none(*pte
)) {
430 kvm_set_pte(pte
, __pte(0));
431 put_page(virt_to_page(pte
));
433 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
435 if (hyp_pte_table_empty(start_pte
))
436 clear_hyp_pmd_entry(pmd
);
439 static void unmap_hyp_pmds(pud_t
*pud
, phys_addr_t addr
, phys_addr_t end
)
442 pmd_t
*pmd
, *start_pmd
;
444 start_pmd
= pmd
= pmd_offset(pud
, addr
);
446 next
= pmd_addr_end(addr
, end
);
447 /* Hyp doesn't use huge pmds */
449 unmap_hyp_ptes(pmd
, addr
, next
);
450 } while (pmd
++, addr
= next
, addr
!= end
);
452 if (hyp_pmd_table_empty(start_pmd
))
453 clear_hyp_pud_entry(pud
);
456 static void unmap_hyp_puds(pgd_t
*pgd
, phys_addr_t addr
, phys_addr_t end
)
459 pud_t
*pud
, *start_pud
;
461 start_pud
= pud
= pud_offset(pgd
, addr
);
463 next
= pud_addr_end(addr
, end
);
464 /* Hyp doesn't use huge puds */
466 unmap_hyp_pmds(pud
, addr
, next
);
467 } while (pud
++, addr
= next
, addr
!= end
);
469 if (hyp_pud_table_empty(start_pud
))
470 clear_hyp_pgd_entry(pgd
);
473 static void unmap_hyp_range(pgd_t
*pgdp
, phys_addr_t start
, u64 size
)
476 phys_addr_t addr
= start
, end
= start
+ size
;
480 * We don't unmap anything from HYP, except at the hyp tear down.
481 * Hence, we don't have to invalidate the TLBs here.
483 pgd
= pgdp
+ pgd_index(addr
);
485 next
= pgd_addr_end(addr
, end
);
487 unmap_hyp_puds(pgd
, addr
, next
);
488 } while (pgd
++, addr
= next
, addr
!= end
);
492 * free_hyp_pgds - free Hyp-mode page tables
494 * Assumes hyp_pgd is a page table used strictly in Hyp-mode and
495 * therefore contains either mappings in the kernel memory area (above
496 * PAGE_OFFSET), or device mappings in the vmalloc range (from
497 * VMALLOC_START to VMALLOC_END).
499 * boot_hyp_pgd should only map two pages for the init code.
501 void free_hyp_pgds(void)
505 mutex_lock(&kvm_hyp_pgd_mutex
);
508 unmap_hyp_range(boot_hyp_pgd
, hyp_idmap_start
, PAGE_SIZE
);
509 free_pages((unsigned long)boot_hyp_pgd
, hyp_pgd_order
);
514 unmap_hyp_range(hyp_pgd
, hyp_idmap_start
, PAGE_SIZE
);
515 for (addr
= PAGE_OFFSET
; virt_addr_valid(addr
); addr
+= PGDIR_SIZE
)
516 unmap_hyp_range(hyp_pgd
, kern_hyp_va(addr
), PGDIR_SIZE
);
517 for (addr
= VMALLOC_START
; is_vmalloc_addr((void*)addr
); addr
+= PGDIR_SIZE
)
518 unmap_hyp_range(hyp_pgd
, kern_hyp_va(addr
), PGDIR_SIZE
);
520 free_pages((unsigned long)hyp_pgd
, hyp_pgd_order
);
523 if (merged_hyp_pgd
) {
524 clear_page(merged_hyp_pgd
);
525 free_page((unsigned long)merged_hyp_pgd
);
526 merged_hyp_pgd
= NULL
;
529 mutex_unlock(&kvm_hyp_pgd_mutex
);
532 static void create_hyp_pte_mappings(pmd_t
*pmd
, unsigned long start
,
533 unsigned long end
, unsigned long pfn
,
541 pte
= pte_offset_kernel(pmd
, addr
);
542 kvm_set_pte(pte
, pfn_pte(pfn
, prot
));
543 get_page(virt_to_page(pte
));
544 kvm_flush_dcache_to_poc(pte
, sizeof(*pte
));
546 } while (addr
+= PAGE_SIZE
, addr
!= end
);
549 static int create_hyp_pmd_mappings(pud_t
*pud
, unsigned long start
,
550 unsigned long end
, unsigned long pfn
,
555 unsigned long addr
, next
;
559 pmd
= pmd_offset(pud
, addr
);
561 BUG_ON(pmd_sect(*pmd
));
563 if (pmd_none(*pmd
)) {
564 pte
= pte_alloc_one_kernel(NULL
, addr
);
566 kvm_err("Cannot allocate Hyp pte\n");
569 pmd_populate_kernel(NULL
, pmd
, pte
);
570 get_page(virt_to_page(pmd
));
571 kvm_flush_dcache_to_poc(pmd
, sizeof(*pmd
));
574 next
= pmd_addr_end(addr
, end
);
576 create_hyp_pte_mappings(pmd
, addr
, next
, pfn
, prot
);
577 pfn
+= (next
- addr
) >> PAGE_SHIFT
;
578 } while (addr
= next
, addr
!= end
);
583 static int create_hyp_pud_mappings(pgd_t
*pgd
, unsigned long start
,
584 unsigned long end
, unsigned long pfn
,
589 unsigned long addr
, next
;
594 pud
= pud_offset(pgd
, addr
);
596 if (pud_none_or_clear_bad(pud
)) {
597 pmd
= pmd_alloc_one(NULL
, addr
);
599 kvm_err("Cannot allocate Hyp pmd\n");
602 pud_populate(NULL
, pud
, pmd
);
603 get_page(virt_to_page(pud
));
604 kvm_flush_dcache_to_poc(pud
, sizeof(*pud
));
607 next
= pud_addr_end(addr
, end
);
608 ret
= create_hyp_pmd_mappings(pud
, addr
, next
, pfn
, prot
);
611 pfn
+= (next
- addr
) >> PAGE_SHIFT
;
612 } while (addr
= next
, addr
!= end
);
617 static int __create_hyp_mappings(pgd_t
*pgdp
,
618 unsigned long start
, unsigned long end
,
619 unsigned long pfn
, pgprot_t prot
)
623 unsigned long addr
, next
;
626 mutex_lock(&kvm_hyp_pgd_mutex
);
627 addr
= start
& PAGE_MASK
;
628 end
= PAGE_ALIGN(end
);
630 pgd
= pgdp
+ pgd_index(addr
);
632 if (pgd_none(*pgd
)) {
633 pud
= pud_alloc_one(NULL
, addr
);
635 kvm_err("Cannot allocate Hyp pud\n");
639 pgd_populate(NULL
, pgd
, pud
);
640 get_page(virt_to_page(pgd
));
641 kvm_flush_dcache_to_poc(pgd
, sizeof(*pgd
));
644 next
= pgd_addr_end(addr
, end
);
645 err
= create_hyp_pud_mappings(pgd
, addr
, next
, pfn
, prot
);
648 pfn
+= (next
- addr
) >> PAGE_SHIFT
;
649 } while (addr
= next
, addr
!= end
);
651 mutex_unlock(&kvm_hyp_pgd_mutex
);
655 static phys_addr_t
kvm_kaddr_to_phys(void *kaddr
)
657 if (!is_vmalloc_addr(kaddr
)) {
658 BUG_ON(!virt_addr_valid(kaddr
));
661 return page_to_phys(vmalloc_to_page(kaddr
)) +
662 offset_in_page(kaddr
);
667 * create_hyp_mappings - duplicate a kernel virtual address range in Hyp mode
668 * @from: The virtual kernel start address of the range
669 * @to: The virtual kernel end address of the range (exclusive)
670 * @prot: The protection to be applied to this range
672 * The same virtual address as the kernel virtual address is also used
673 * in Hyp-mode mapping (modulo HYP_PAGE_OFFSET) to the same underlying
676 int create_hyp_mappings(void *from
, void *to
, pgprot_t prot
)
678 phys_addr_t phys_addr
;
679 unsigned long virt_addr
;
680 unsigned long start
= kern_hyp_va((unsigned long)from
);
681 unsigned long end
= kern_hyp_va((unsigned long)to
);
683 if (is_kernel_in_hyp_mode())
686 start
= start
& PAGE_MASK
;
687 end
= PAGE_ALIGN(end
);
689 for (virt_addr
= start
; virt_addr
< end
; virt_addr
+= PAGE_SIZE
) {
692 phys_addr
= kvm_kaddr_to_phys(from
+ virt_addr
- start
);
693 err
= __create_hyp_mappings(hyp_pgd
, virt_addr
,
694 virt_addr
+ PAGE_SIZE
,
695 __phys_to_pfn(phys_addr
),
705 * create_hyp_io_mappings - duplicate a kernel IO mapping into Hyp mode
706 * @from: The kernel start VA of the range
707 * @to: The kernel end VA of the range (exclusive)
708 * @phys_addr: The physical start address which gets mapped
710 * The resulting HYP VA is the same as the kernel VA, modulo
713 int create_hyp_io_mappings(void *from
, void *to
, phys_addr_t phys_addr
)
715 unsigned long start
= kern_hyp_va((unsigned long)from
);
716 unsigned long end
= kern_hyp_va((unsigned long)to
);
718 if (is_kernel_in_hyp_mode())
721 /* Check for a valid kernel IO mapping */
722 if (!is_vmalloc_addr(from
) || !is_vmalloc_addr(to
- 1))
725 return __create_hyp_mappings(hyp_pgd
, start
, end
,
726 __phys_to_pfn(phys_addr
), PAGE_HYP_DEVICE
);
730 * kvm_alloc_stage2_pgd - allocate level-1 table for stage-2 translation.
731 * @kvm: The KVM struct pointer for the VM.
733 * Allocates only the stage-2 HW PGD level table(s) (can support either full
734 * 40-bit input addresses or limited to 32-bit input addresses). Clears the
737 * Note we don't need locking here as this is only called when the VM is
738 * created, which can only be done once.
740 int kvm_alloc_stage2_pgd(struct kvm
*kvm
)
744 if (kvm
->arch
.pgd
!= NULL
) {
745 kvm_err("kvm_arch already initialized?\n");
749 /* Allocate the HW PGD, making sure that each page gets its own refcount */
750 pgd
= alloc_pages_exact(S2_PGD_SIZE
, GFP_KERNEL
| __GFP_ZERO
);
758 static void stage2_unmap_memslot(struct kvm
*kvm
,
759 struct kvm_memory_slot
*memslot
)
761 hva_t hva
= memslot
->userspace_addr
;
762 phys_addr_t addr
= memslot
->base_gfn
<< PAGE_SHIFT
;
763 phys_addr_t size
= PAGE_SIZE
* memslot
->npages
;
764 hva_t reg_end
= hva
+ size
;
767 * A memory region could potentially cover multiple VMAs, and any holes
768 * between them, so iterate over all of them to find out if we should
771 * +--------------------------------------------+
772 * +---------------+----------------+ +----------------+
773 * | : VMA 1 | VMA 2 | | VMA 3 : |
774 * +---------------+----------------+ +----------------+
776 * +--------------------------------------------+
779 struct vm_area_struct
*vma
= find_vma(current
->mm
, hva
);
780 hva_t vm_start
, vm_end
;
782 if (!vma
|| vma
->vm_start
>= reg_end
)
786 * Take the intersection of this VMA with the memory region
788 vm_start
= max(hva
, vma
->vm_start
);
789 vm_end
= min(reg_end
, vma
->vm_end
);
791 if (!(vma
->vm_flags
& VM_PFNMAP
)) {
792 gpa_t gpa
= addr
+ (vm_start
- memslot
->userspace_addr
);
793 unmap_stage2_range(kvm
, gpa
, vm_end
- vm_start
);
796 } while (hva
< reg_end
);
800 * stage2_unmap_vm - Unmap Stage-2 RAM mappings
801 * @kvm: The struct kvm pointer
803 * Go through the memregions and unmap any reguler RAM
804 * backing memory already mapped to the VM.
806 void stage2_unmap_vm(struct kvm
*kvm
)
808 struct kvm_memslots
*slots
;
809 struct kvm_memory_slot
*memslot
;
812 idx
= srcu_read_lock(&kvm
->srcu
);
813 down_read(¤t
->mm
->mmap_sem
);
814 spin_lock(&kvm
->mmu_lock
);
816 slots
= kvm_memslots(kvm
);
817 kvm_for_each_memslot(memslot
, slots
)
818 stage2_unmap_memslot(kvm
, memslot
);
820 spin_unlock(&kvm
->mmu_lock
);
821 up_read(¤t
->mm
->mmap_sem
);
822 srcu_read_unlock(&kvm
->srcu
, idx
);
826 * kvm_free_stage2_pgd - free all stage-2 tables
827 * @kvm: The KVM struct pointer for the VM.
829 * Walks the level-1 page table pointed to by kvm->arch.pgd and frees all
830 * underlying level-2 and level-3 tables before freeing the actual level-1 table
831 * and setting the struct pointer to NULL.
833 * Note we don't need locking here as this is only called when the VM is
834 * destroyed, which can only be done once.
836 void kvm_free_stage2_pgd(struct kvm
*kvm
)
838 if (kvm
->arch
.pgd
== NULL
)
841 spin_lock(&kvm
->mmu_lock
);
842 unmap_stage2_range(kvm
, 0, KVM_PHYS_SIZE
);
843 spin_unlock(&kvm
->mmu_lock
);
845 /* Free the HW pgd, one page at a time */
846 free_pages_exact(kvm
->arch
.pgd
, S2_PGD_SIZE
);
847 kvm
->arch
.pgd
= NULL
;
850 static pud_t
*stage2_get_pud(struct kvm
*kvm
, struct kvm_mmu_memory_cache
*cache
,
856 pgd
= kvm
->arch
.pgd
+ stage2_pgd_index(addr
);
857 if (WARN_ON(stage2_pgd_none(*pgd
))) {
860 pud
= mmu_memory_cache_alloc(cache
);
861 stage2_pgd_populate(pgd
, pud
);
862 get_page(virt_to_page(pgd
));
865 return stage2_pud_offset(pgd
, addr
);
868 static pmd_t
*stage2_get_pmd(struct kvm
*kvm
, struct kvm_mmu_memory_cache
*cache
,
874 pud
= stage2_get_pud(kvm
, cache
, addr
);
875 if (stage2_pud_none(*pud
)) {
878 pmd
= mmu_memory_cache_alloc(cache
);
879 stage2_pud_populate(pud
, pmd
);
880 get_page(virt_to_page(pud
));
883 return stage2_pmd_offset(pud
, addr
);
886 static int stage2_set_pmd_huge(struct kvm
*kvm
, struct kvm_mmu_memory_cache
887 *cache
, phys_addr_t addr
, const pmd_t
*new_pmd
)
891 pmd
= stage2_get_pmd(kvm
, cache
, addr
);
895 * Mapping in huge pages should only happen through a fault. If a
896 * page is merged into a transparent huge page, the individual
897 * subpages of that huge page should be unmapped through MMU
898 * notifiers before we get here.
900 * Merging of CompoundPages is not supported; they should become
901 * splitting first, unmapped, merged, and mapped back in on-demand.
903 VM_BUG_ON(pmd_present(*pmd
) && pmd_pfn(*pmd
) != pmd_pfn(*new_pmd
));
906 if (pmd_present(old_pmd
)) {
908 kvm_tlb_flush_vmid_ipa(kvm
, addr
);
910 get_page(virt_to_page(pmd
));
913 kvm_set_pmd(pmd
, *new_pmd
);
917 static int stage2_set_pte(struct kvm
*kvm
, struct kvm_mmu_memory_cache
*cache
,
918 phys_addr_t addr
, const pte_t
*new_pte
,
923 bool iomap
= flags
& KVM_S2PTE_FLAG_IS_IOMAP
;
924 bool logging_active
= flags
& KVM_S2_FLAG_LOGGING_ACTIVE
;
926 VM_BUG_ON(logging_active
&& !cache
);
928 /* Create stage-2 page table mapping - Levels 0 and 1 */
929 pmd
= stage2_get_pmd(kvm
, cache
, addr
);
932 * Ignore calls from kvm_set_spte_hva for unallocated
939 * While dirty page logging - dissolve huge PMD, then continue on to
943 stage2_dissolve_pmd(kvm
, addr
, pmd
);
945 /* Create stage-2 page mappings - Level 2 */
946 if (pmd_none(*pmd
)) {
948 return 0; /* ignore calls from kvm_set_spte_hva */
949 pte
= mmu_memory_cache_alloc(cache
);
950 pmd_populate_kernel(NULL
, pmd
, pte
);
951 get_page(virt_to_page(pmd
));
954 pte
= pte_offset_kernel(pmd
, addr
);
956 if (iomap
&& pte_present(*pte
))
959 /* Create 2nd stage page table mapping - Level 3 */
961 if (pte_present(old_pte
)) {
962 kvm_set_pte(pte
, __pte(0));
963 kvm_tlb_flush_vmid_ipa(kvm
, addr
);
965 get_page(virt_to_page(pte
));
968 kvm_set_pte(pte
, *new_pte
);
972 #ifndef __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
973 static int stage2_ptep_test_and_clear_young(pte_t
*pte
)
975 if (pte_young(*pte
)) {
976 *pte
= pte_mkold(*pte
);
982 static int stage2_ptep_test_and_clear_young(pte_t
*pte
)
984 return __ptep_test_and_clear_young(pte
);
988 static int stage2_pmdp_test_and_clear_young(pmd_t
*pmd
)
990 return stage2_ptep_test_and_clear_young((pte_t
*)pmd
);
994 * kvm_phys_addr_ioremap - map a device range to guest IPA
996 * @kvm: The KVM pointer
997 * @guest_ipa: The IPA at which to insert the mapping
998 * @pa: The physical address of the device
999 * @size: The size of the mapping
1001 int kvm_phys_addr_ioremap(struct kvm
*kvm
, phys_addr_t guest_ipa
,
1002 phys_addr_t pa
, unsigned long size
, bool writable
)
1004 phys_addr_t addr
, end
;
1007 struct kvm_mmu_memory_cache cache
= { 0, };
1009 end
= (guest_ipa
+ size
+ PAGE_SIZE
- 1) & PAGE_MASK
;
1010 pfn
= __phys_to_pfn(pa
);
1012 for (addr
= guest_ipa
; addr
< end
; addr
+= PAGE_SIZE
) {
1013 pte_t pte
= pfn_pte(pfn
, PAGE_S2_DEVICE
);
1016 pte
= kvm_s2pte_mkwrite(pte
);
1018 ret
= mmu_topup_memory_cache(&cache
, KVM_MMU_CACHE_MIN_PAGES
,
1022 spin_lock(&kvm
->mmu_lock
);
1023 ret
= stage2_set_pte(kvm
, &cache
, addr
, &pte
,
1024 KVM_S2PTE_FLAG_IS_IOMAP
);
1025 spin_unlock(&kvm
->mmu_lock
);
1033 mmu_free_memory_cache(&cache
);
1037 static bool transparent_hugepage_adjust(kvm_pfn_t
*pfnp
, phys_addr_t
*ipap
)
1039 kvm_pfn_t pfn
= *pfnp
;
1040 gfn_t gfn
= *ipap
>> PAGE_SHIFT
;
1042 if (PageTransCompoundMap(pfn_to_page(pfn
))) {
1045 * The address we faulted on is backed by a transparent huge
1046 * page. However, because we map the compound huge page and
1047 * not the individual tail page, we need to transfer the
1048 * refcount to the head page. We have to be careful that the
1049 * THP doesn't start to split while we are adjusting the
1052 * We are sure this doesn't happen, because mmu_notifier_retry
1053 * was successful and we are holding the mmu_lock, so if this
1054 * THP is trying to split, it will be blocked in the mmu
1055 * notifier before touching any of the pages, specifically
1056 * before being able to call __split_huge_page_refcount().
1058 * We can therefore safely transfer the refcount from PG_tail
1059 * to PG_head and switch the pfn from a tail page to the head
1062 mask
= PTRS_PER_PMD
- 1;
1063 VM_BUG_ON((gfn
& mask
) != (pfn
& mask
));
1066 kvm_release_pfn_clean(pfn
);
1078 static bool kvm_is_write_fault(struct kvm_vcpu
*vcpu
)
1080 if (kvm_vcpu_trap_is_iabt(vcpu
))
1083 return kvm_vcpu_dabt_iswrite(vcpu
);
1087 * stage2_wp_ptes - write protect PMD range
1088 * @pmd: pointer to pmd entry
1089 * @addr: range start address
1090 * @end: range end address
1092 static void stage2_wp_ptes(pmd_t
*pmd
, phys_addr_t addr
, phys_addr_t end
)
1096 pte
= pte_offset_kernel(pmd
, addr
);
1098 if (!pte_none(*pte
)) {
1099 if (!kvm_s2pte_readonly(pte
))
1100 kvm_set_s2pte_readonly(pte
);
1102 } while (pte
++, addr
+= PAGE_SIZE
, addr
!= end
);
1106 * stage2_wp_pmds - write protect PUD range
1107 * @pud: pointer to pud entry
1108 * @addr: range start address
1109 * @end: range end address
1111 static void stage2_wp_pmds(pud_t
*pud
, phys_addr_t addr
, phys_addr_t end
)
1116 pmd
= stage2_pmd_offset(pud
, addr
);
1119 next
= stage2_pmd_addr_end(addr
, end
);
1120 if (!pmd_none(*pmd
)) {
1121 if (pmd_thp_or_huge(*pmd
)) {
1122 if (!kvm_s2pmd_readonly(pmd
))
1123 kvm_set_s2pmd_readonly(pmd
);
1125 stage2_wp_ptes(pmd
, addr
, next
);
1128 } while (pmd
++, addr
= next
, addr
!= end
);
1132 * stage2_wp_puds - write protect PGD range
1133 * @pgd: pointer to pgd entry
1134 * @addr: range start address
1135 * @end: range end address
1137 * Process PUD entries, for a huge PUD we cause a panic.
1139 static void stage2_wp_puds(pgd_t
*pgd
, phys_addr_t addr
, phys_addr_t end
)
1144 pud
= stage2_pud_offset(pgd
, addr
);
1146 next
= stage2_pud_addr_end(addr
, end
);
1147 if (!stage2_pud_none(*pud
)) {
1148 /* TODO:PUD not supported, revisit later if supported */
1149 BUG_ON(stage2_pud_huge(*pud
));
1150 stage2_wp_pmds(pud
, addr
, next
);
1152 } while (pud
++, addr
= next
, addr
!= end
);
1156 * stage2_wp_range() - write protect stage2 memory region range
1157 * @kvm: The KVM pointer
1158 * @addr: Start address of range
1159 * @end: End address of range
1161 static void stage2_wp_range(struct kvm
*kvm
, phys_addr_t addr
, phys_addr_t end
)
1166 pgd
= kvm
->arch
.pgd
+ stage2_pgd_index(addr
);
1169 * Release kvm_mmu_lock periodically if the memory region is
1170 * large. Otherwise, we may see kernel panics with
1171 * CONFIG_DETECT_HUNG_TASK, CONFIG_LOCKUP_DETECTOR,
1172 * CONFIG_LOCKDEP. Additionally, holding the lock too long
1173 * will also starve other vCPUs.
1175 if (need_resched() || spin_needbreak(&kvm
->mmu_lock
))
1176 cond_resched_lock(&kvm
->mmu_lock
);
1178 next
= stage2_pgd_addr_end(addr
, end
);
1179 if (stage2_pgd_present(*pgd
))
1180 stage2_wp_puds(pgd
, addr
, next
);
1181 } while (pgd
++, addr
= next
, addr
!= end
);
1185 * kvm_mmu_wp_memory_region() - write protect stage 2 entries for memory slot
1186 * @kvm: The KVM pointer
1187 * @slot: The memory slot to write protect
1189 * Called to start logging dirty pages after memory region
1190 * KVM_MEM_LOG_DIRTY_PAGES operation is called. After this function returns
1191 * all present PMD and PTEs are write protected in the memory region.
1192 * Afterwards read of dirty page log can be called.
1194 * Acquires kvm_mmu_lock. Called with kvm->slots_lock mutex acquired,
1195 * serializing operations for VM memory regions.
1197 void kvm_mmu_wp_memory_region(struct kvm
*kvm
, int slot
)
1199 struct kvm_memslots
*slots
= kvm_memslots(kvm
);
1200 struct kvm_memory_slot
*memslot
= id_to_memslot(slots
, slot
);
1201 phys_addr_t start
= memslot
->base_gfn
<< PAGE_SHIFT
;
1202 phys_addr_t end
= (memslot
->base_gfn
+ memslot
->npages
) << PAGE_SHIFT
;
1204 spin_lock(&kvm
->mmu_lock
);
1205 stage2_wp_range(kvm
, start
, end
);
1206 spin_unlock(&kvm
->mmu_lock
);
1207 kvm_flush_remote_tlbs(kvm
);
1211 * kvm_mmu_write_protect_pt_masked() - write protect dirty pages
1212 * @kvm: The KVM pointer
1213 * @slot: The memory slot associated with mask
1214 * @gfn_offset: The gfn offset in memory slot
1215 * @mask: The mask of dirty pages at offset 'gfn_offset' in this memory
1216 * slot to be write protected
1218 * Walks bits set in mask write protects the associated pte's. Caller must
1219 * acquire kvm_mmu_lock.
1221 static void kvm_mmu_write_protect_pt_masked(struct kvm
*kvm
,
1222 struct kvm_memory_slot
*slot
,
1223 gfn_t gfn_offset
, unsigned long mask
)
1225 phys_addr_t base_gfn
= slot
->base_gfn
+ gfn_offset
;
1226 phys_addr_t start
= (base_gfn
+ __ffs(mask
)) << PAGE_SHIFT
;
1227 phys_addr_t end
= (base_gfn
+ __fls(mask
) + 1) << PAGE_SHIFT
;
1229 stage2_wp_range(kvm
, start
, end
);
1233 * kvm_arch_mmu_enable_log_dirty_pt_masked - enable dirty logging for selected
1236 * It calls kvm_mmu_write_protect_pt_masked to write protect selected pages to
1237 * enable dirty logging for them.
1239 void kvm_arch_mmu_enable_log_dirty_pt_masked(struct kvm
*kvm
,
1240 struct kvm_memory_slot
*slot
,
1241 gfn_t gfn_offset
, unsigned long mask
)
1243 kvm_mmu_write_protect_pt_masked(kvm
, slot
, gfn_offset
, mask
);
1246 static void coherent_cache_guest_page(struct kvm_vcpu
*vcpu
, kvm_pfn_t pfn
,
1249 __coherent_cache_guest_page(vcpu
, pfn
, size
);
1252 static int user_mem_abort(struct kvm_vcpu
*vcpu
, phys_addr_t fault_ipa
,
1253 struct kvm_memory_slot
*memslot
, unsigned long hva
,
1254 unsigned long fault_status
)
1257 bool write_fault
, writable
, hugetlb
= false, force_pte
= false;
1258 unsigned long mmu_seq
;
1259 gfn_t gfn
= fault_ipa
>> PAGE_SHIFT
;
1260 struct kvm
*kvm
= vcpu
->kvm
;
1261 struct kvm_mmu_memory_cache
*memcache
= &vcpu
->arch
.mmu_page_cache
;
1262 struct vm_area_struct
*vma
;
1264 pgprot_t mem_type
= PAGE_S2
;
1265 bool logging_active
= memslot_is_logging(memslot
);
1266 unsigned long flags
= 0;
1268 write_fault
= kvm_is_write_fault(vcpu
);
1269 if (fault_status
== FSC_PERM
&& !write_fault
) {
1270 kvm_err("Unexpected L2 read permission error\n");
1274 /* Let's check if we will get back a huge page backed by hugetlbfs */
1275 down_read(¤t
->mm
->mmap_sem
);
1276 vma
= find_vma_intersection(current
->mm
, hva
, hva
+ 1);
1277 if (unlikely(!vma
)) {
1278 kvm_err("Failed to find VMA for hva 0x%lx\n", hva
);
1279 up_read(¤t
->mm
->mmap_sem
);
1283 if (is_vm_hugetlb_page(vma
) && !logging_active
) {
1285 gfn
= (fault_ipa
& PMD_MASK
) >> PAGE_SHIFT
;
1288 * Pages belonging to memslots that don't have the same
1289 * alignment for userspace and IPA cannot be mapped using
1290 * block descriptors even if the pages belong to a THP for
1291 * the process, because the stage-2 block descriptor will
1292 * cover more than a single THP and we loose atomicity for
1293 * unmapping, updates, and splits of the THP or other pages
1294 * in the stage-2 block range.
1296 if ((memslot
->userspace_addr
& ~PMD_MASK
) !=
1297 ((memslot
->base_gfn
<< PAGE_SHIFT
) & ~PMD_MASK
))
1300 up_read(¤t
->mm
->mmap_sem
);
1302 /* We need minimum second+third level pages */
1303 ret
= mmu_topup_memory_cache(memcache
, KVM_MMU_CACHE_MIN_PAGES
,
1308 mmu_seq
= vcpu
->kvm
->mmu_notifier_seq
;
1310 * Ensure the read of mmu_notifier_seq happens before we call
1311 * gfn_to_pfn_prot (which calls get_user_pages), so that we don't risk
1312 * the page we just got a reference to gets unmapped before we have a
1313 * chance to grab the mmu_lock, which ensure that if the page gets
1314 * unmapped afterwards, the call to kvm_unmap_hva will take it away
1315 * from us again properly. This smp_rmb() interacts with the smp_wmb()
1316 * in kvm_mmu_notifier_invalidate_<page|range_end>.
1320 pfn
= gfn_to_pfn_prot(kvm
, gfn
, write_fault
, &writable
);
1321 if (is_error_noslot_pfn(pfn
))
1324 if (kvm_is_device_pfn(pfn
)) {
1325 mem_type
= PAGE_S2_DEVICE
;
1326 flags
|= KVM_S2PTE_FLAG_IS_IOMAP
;
1327 } else if (logging_active
) {
1329 * Faults on pages in a memslot with logging enabled
1330 * should not be mapped with huge pages (it introduces churn
1331 * and performance degradation), so force a pte mapping.
1334 flags
|= KVM_S2_FLAG_LOGGING_ACTIVE
;
1337 * Only actually map the page as writable if this was a write
1344 spin_lock(&kvm
->mmu_lock
);
1345 if (mmu_notifier_retry(kvm
, mmu_seq
))
1348 if (!hugetlb
&& !force_pte
)
1349 hugetlb
= transparent_hugepage_adjust(&pfn
, &fault_ipa
);
1352 pmd_t new_pmd
= pfn_pmd(pfn
, mem_type
);
1353 new_pmd
= pmd_mkhuge(new_pmd
);
1355 new_pmd
= kvm_s2pmd_mkwrite(new_pmd
);
1356 kvm_set_pfn_dirty(pfn
);
1358 coherent_cache_guest_page(vcpu
, pfn
, PMD_SIZE
);
1359 ret
= stage2_set_pmd_huge(kvm
, memcache
, fault_ipa
, &new_pmd
);
1361 pte_t new_pte
= pfn_pte(pfn
, mem_type
);
1364 new_pte
= kvm_s2pte_mkwrite(new_pte
);
1365 kvm_set_pfn_dirty(pfn
);
1366 mark_page_dirty(kvm
, gfn
);
1368 coherent_cache_guest_page(vcpu
, pfn
, PAGE_SIZE
);
1369 ret
= stage2_set_pte(kvm
, memcache
, fault_ipa
, &new_pte
, flags
);
1373 spin_unlock(&kvm
->mmu_lock
);
1374 kvm_set_pfn_accessed(pfn
);
1375 kvm_release_pfn_clean(pfn
);
1380 * Resolve the access fault by making the page young again.
1381 * Note that because the faulting entry is guaranteed not to be
1382 * cached in the TLB, we don't need to invalidate anything.
1383 * Only the HW Access Flag updates are supported for Stage 2 (no DBM),
1384 * so there is no need for atomic (pte|pmd)_mkyoung operations.
1386 static void handle_access_fault(struct kvm_vcpu
*vcpu
, phys_addr_t fault_ipa
)
1391 bool pfn_valid
= false;
1393 trace_kvm_access_fault(fault_ipa
);
1395 spin_lock(&vcpu
->kvm
->mmu_lock
);
1397 pmd
= stage2_get_pmd(vcpu
->kvm
, NULL
, fault_ipa
);
1398 if (!pmd
|| pmd_none(*pmd
)) /* Nothing there */
1401 if (pmd_thp_or_huge(*pmd
)) { /* THP, HugeTLB */
1402 *pmd
= pmd_mkyoung(*pmd
);
1403 pfn
= pmd_pfn(*pmd
);
1408 pte
= pte_offset_kernel(pmd
, fault_ipa
);
1409 if (pte_none(*pte
)) /* Nothing there either */
1412 *pte
= pte_mkyoung(*pte
); /* Just a page... */
1413 pfn
= pte_pfn(*pte
);
1416 spin_unlock(&vcpu
->kvm
->mmu_lock
);
1418 kvm_set_pfn_accessed(pfn
);
1422 * kvm_handle_guest_abort - handles all 2nd stage aborts
1423 * @vcpu: the VCPU pointer
1424 * @run: the kvm_run structure
1426 * Any abort that gets to the host is almost guaranteed to be caused by a
1427 * missing second stage translation table entry, which can mean that either the
1428 * guest simply needs more memory and we must allocate an appropriate page or it
1429 * can mean that the guest tried to access I/O memory, which is emulated by user
1430 * space. The distinction is based on the IPA causing the fault and whether this
1431 * memory region has been registered as standard RAM by user space.
1433 int kvm_handle_guest_abort(struct kvm_vcpu
*vcpu
, struct kvm_run
*run
)
1435 unsigned long fault_status
;
1436 phys_addr_t fault_ipa
;
1437 struct kvm_memory_slot
*memslot
;
1439 bool is_iabt
, write_fault
, writable
;
1443 is_iabt
= kvm_vcpu_trap_is_iabt(vcpu
);
1444 if (unlikely(!is_iabt
&& kvm_vcpu_dabt_isextabt(vcpu
))) {
1445 kvm_inject_vabt(vcpu
);
1449 fault_ipa
= kvm_vcpu_get_fault_ipa(vcpu
);
1451 trace_kvm_guest_fault(*vcpu_pc(vcpu
), kvm_vcpu_get_hsr(vcpu
),
1452 kvm_vcpu_get_hfar(vcpu
), fault_ipa
);
1454 /* Check the stage-2 fault is trans. fault or write fault */
1455 fault_status
= kvm_vcpu_trap_get_fault_type(vcpu
);
1456 if (fault_status
!= FSC_FAULT
&& fault_status
!= FSC_PERM
&&
1457 fault_status
!= FSC_ACCESS
) {
1458 kvm_err("Unsupported FSC: EC=%#x xFSC=%#lx ESR_EL2=%#lx\n",
1459 kvm_vcpu_trap_get_class(vcpu
),
1460 (unsigned long)kvm_vcpu_trap_get_fault(vcpu
),
1461 (unsigned long)kvm_vcpu_get_hsr(vcpu
));
1465 idx
= srcu_read_lock(&vcpu
->kvm
->srcu
);
1467 gfn
= fault_ipa
>> PAGE_SHIFT
;
1468 memslot
= gfn_to_memslot(vcpu
->kvm
, gfn
);
1469 hva
= gfn_to_hva_memslot_prot(memslot
, gfn
, &writable
);
1470 write_fault
= kvm_is_write_fault(vcpu
);
1471 if (kvm_is_error_hva(hva
) || (write_fault
&& !writable
)) {
1473 /* Prefetch Abort on I/O address */
1474 kvm_inject_pabt(vcpu
, kvm_vcpu_get_hfar(vcpu
));
1480 * Check for a cache maintenance operation. Since we
1481 * ended-up here, we know it is outside of any memory
1482 * slot. But we can't find out if that is for a device,
1483 * or if the guest is just being stupid. The only thing
1484 * we know for sure is that this range cannot be cached.
1486 * So let's assume that the guest is just being
1487 * cautious, and skip the instruction.
1489 if (kvm_vcpu_dabt_is_cm(vcpu
)) {
1490 kvm_skip_instr(vcpu
, kvm_vcpu_trap_il_is32bit(vcpu
));
1496 * The IPA is reported as [MAX:12], so we need to
1497 * complement it with the bottom 12 bits from the
1498 * faulting VA. This is always 12 bits, irrespective
1501 fault_ipa
|= kvm_vcpu_get_hfar(vcpu
) & ((1 << 12) - 1);
1502 ret
= io_mem_abort(vcpu
, run
, fault_ipa
);
1506 /* Userspace should not be able to register out-of-bounds IPAs */
1507 VM_BUG_ON(fault_ipa
>= KVM_PHYS_SIZE
);
1509 if (fault_status
== FSC_ACCESS
) {
1510 handle_access_fault(vcpu
, fault_ipa
);
1515 ret
= user_mem_abort(vcpu
, fault_ipa
, memslot
, hva
, fault_status
);
1519 srcu_read_unlock(&vcpu
->kvm
->srcu
, idx
);
1523 static int handle_hva_to_gpa(struct kvm
*kvm
,
1524 unsigned long start
,
1526 int (*handler
)(struct kvm
*kvm
,
1527 gpa_t gpa
, u64 size
,
1531 struct kvm_memslots
*slots
;
1532 struct kvm_memory_slot
*memslot
;
1535 slots
= kvm_memslots(kvm
);
1537 /* we only care about the pages that the guest sees */
1538 kvm_for_each_memslot(memslot
, slots
) {
1539 unsigned long hva_start
, hva_end
;
1542 hva_start
= max(start
, memslot
->userspace_addr
);
1543 hva_end
= min(end
, memslot
->userspace_addr
+
1544 (memslot
->npages
<< PAGE_SHIFT
));
1545 if (hva_start
>= hva_end
)
1548 gpa
= hva_to_gfn_memslot(hva_start
, memslot
) << PAGE_SHIFT
;
1549 ret
|= handler(kvm
, gpa
, (u64
)(hva_end
- hva_start
), data
);
1555 static int kvm_unmap_hva_handler(struct kvm
*kvm
, gpa_t gpa
, u64 size
, void *data
)
1557 unmap_stage2_range(kvm
, gpa
, size
);
1561 int kvm_unmap_hva(struct kvm
*kvm
, unsigned long hva
)
1563 unsigned long end
= hva
+ PAGE_SIZE
;
1568 trace_kvm_unmap_hva(hva
);
1569 handle_hva_to_gpa(kvm
, hva
, end
, &kvm_unmap_hva_handler
, NULL
);
1573 int kvm_unmap_hva_range(struct kvm
*kvm
,
1574 unsigned long start
, unsigned long end
)
1579 trace_kvm_unmap_hva_range(start
, end
);
1580 handle_hva_to_gpa(kvm
, start
, end
, &kvm_unmap_hva_handler
, NULL
);
1584 static int kvm_set_spte_handler(struct kvm
*kvm
, gpa_t gpa
, u64 size
, void *data
)
1586 pte_t
*pte
= (pte_t
*)data
;
1588 WARN_ON(size
!= PAGE_SIZE
);
1590 * We can always call stage2_set_pte with KVM_S2PTE_FLAG_LOGGING_ACTIVE
1591 * flag clear because MMU notifiers will have unmapped a huge PMD before
1592 * calling ->change_pte() (which in turn calls kvm_set_spte_hva()) and
1593 * therefore stage2_set_pte() never needs to clear out a huge PMD
1594 * through this calling path.
1596 stage2_set_pte(kvm
, NULL
, gpa
, pte
, 0);
1601 void kvm_set_spte_hva(struct kvm
*kvm
, unsigned long hva
, pte_t pte
)
1603 unsigned long end
= hva
+ PAGE_SIZE
;
1609 trace_kvm_set_spte_hva(hva
);
1610 stage2_pte
= pfn_pte(pte_pfn(pte
), PAGE_S2
);
1611 handle_hva_to_gpa(kvm
, hva
, end
, &kvm_set_spte_handler
, &stage2_pte
);
1614 static int kvm_age_hva_handler(struct kvm
*kvm
, gpa_t gpa
, u64 size
, void *data
)
1619 WARN_ON(size
!= PAGE_SIZE
&& size
!= PMD_SIZE
);
1620 pmd
= stage2_get_pmd(kvm
, NULL
, gpa
);
1621 if (!pmd
|| pmd_none(*pmd
)) /* Nothing there */
1624 if (pmd_thp_or_huge(*pmd
)) /* THP, HugeTLB */
1625 return stage2_pmdp_test_and_clear_young(pmd
);
1627 pte
= pte_offset_kernel(pmd
, gpa
);
1631 return stage2_ptep_test_and_clear_young(pte
);
1634 static int kvm_test_age_hva_handler(struct kvm
*kvm
, gpa_t gpa
, u64 size
, void *data
)
1639 WARN_ON(size
!= PAGE_SIZE
&& size
!= PMD_SIZE
);
1640 pmd
= stage2_get_pmd(kvm
, NULL
, gpa
);
1641 if (!pmd
|| pmd_none(*pmd
)) /* Nothing there */
1644 if (pmd_thp_or_huge(*pmd
)) /* THP, HugeTLB */
1645 return pmd_young(*pmd
);
1647 pte
= pte_offset_kernel(pmd
, gpa
);
1648 if (!pte_none(*pte
)) /* Just a page... */
1649 return pte_young(*pte
);
1654 int kvm_age_hva(struct kvm
*kvm
, unsigned long start
, unsigned long end
)
1656 trace_kvm_age_hva(start
, end
);
1657 return handle_hva_to_gpa(kvm
, start
, end
, kvm_age_hva_handler
, NULL
);
1660 int kvm_test_age_hva(struct kvm
*kvm
, unsigned long hva
)
1662 trace_kvm_test_age_hva(hva
);
1663 return handle_hva_to_gpa(kvm
, hva
, hva
, kvm_test_age_hva_handler
, NULL
);
1666 void kvm_mmu_free_memory_caches(struct kvm_vcpu
*vcpu
)
1668 mmu_free_memory_cache(&vcpu
->arch
.mmu_page_cache
);
1671 phys_addr_t
kvm_mmu_get_httbr(void)
1673 if (__kvm_cpu_uses_extended_idmap())
1674 return virt_to_phys(merged_hyp_pgd
);
1676 return virt_to_phys(hyp_pgd
);
1679 phys_addr_t
kvm_get_idmap_vector(void)
1681 return hyp_idmap_vector
;
1684 static int kvm_map_idmap_text(pgd_t
*pgd
)
1688 /* Create the idmap in the boot page tables */
1689 err
= __create_hyp_mappings(pgd
,
1690 hyp_idmap_start
, hyp_idmap_end
,
1691 __phys_to_pfn(hyp_idmap_start
),
1694 kvm_err("Failed to idmap %lx-%lx\n",
1695 hyp_idmap_start
, hyp_idmap_end
);
1700 int kvm_mmu_init(void)
1704 hyp_idmap_start
= kvm_virt_to_phys(__hyp_idmap_text_start
);
1705 hyp_idmap_end
= kvm_virt_to_phys(__hyp_idmap_text_end
);
1706 hyp_idmap_vector
= kvm_virt_to_phys(__kvm_hyp_init
);
1709 * We rely on the linker script to ensure at build time that the HYP
1710 * init code does not cross a page boundary.
1712 BUG_ON((hyp_idmap_start
^ (hyp_idmap_end
- 1)) & PAGE_MASK
);
1714 kvm_info("IDMAP page: %lx\n", hyp_idmap_start
);
1715 kvm_info("HYP VA range: %lx:%lx\n",
1716 kern_hyp_va(PAGE_OFFSET
), kern_hyp_va(~0UL));
1718 if (hyp_idmap_start
>= kern_hyp_va(PAGE_OFFSET
) &&
1719 hyp_idmap_start
< kern_hyp_va(~0UL) &&
1720 hyp_idmap_start
!= (unsigned long)__hyp_idmap_text_start
) {
1722 * The idmap page is intersecting with the VA space,
1723 * it is not safe to continue further.
1725 kvm_err("IDMAP intersecting with HYP VA, unable to continue\n");
1730 hyp_pgd
= (pgd_t
*)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
, hyp_pgd_order
);
1732 kvm_err("Hyp mode PGD not allocated\n");
1737 if (__kvm_cpu_uses_extended_idmap()) {
1738 boot_hyp_pgd
= (pgd_t
*)__get_free_pages(GFP_KERNEL
| __GFP_ZERO
,
1740 if (!boot_hyp_pgd
) {
1741 kvm_err("Hyp boot PGD not allocated\n");
1746 err
= kvm_map_idmap_text(boot_hyp_pgd
);
1750 merged_hyp_pgd
= (pgd_t
*)__get_free_page(GFP_KERNEL
| __GFP_ZERO
);
1751 if (!merged_hyp_pgd
) {
1752 kvm_err("Failed to allocate extra HYP pgd\n");
1755 __kvm_extend_hypmap(boot_hyp_pgd
, hyp_pgd
, merged_hyp_pgd
,
1758 err
= kvm_map_idmap_text(hyp_pgd
);
1769 void kvm_arch_commit_memory_region(struct kvm
*kvm
,
1770 const struct kvm_userspace_memory_region
*mem
,
1771 const struct kvm_memory_slot
*old
,
1772 const struct kvm_memory_slot
*new,
1773 enum kvm_mr_change change
)
1776 * At this point memslot has been committed and there is an
1777 * allocated dirty_bitmap[], dirty pages will be be tracked while the
1778 * memory slot is write protected.
1780 if (change
!= KVM_MR_DELETE
&& mem
->flags
& KVM_MEM_LOG_DIRTY_PAGES
)
1781 kvm_mmu_wp_memory_region(kvm
, mem
->slot
);
1784 int kvm_arch_prepare_memory_region(struct kvm
*kvm
,
1785 struct kvm_memory_slot
*memslot
,
1786 const struct kvm_userspace_memory_region
*mem
,
1787 enum kvm_mr_change change
)
1789 hva_t hva
= mem
->userspace_addr
;
1790 hva_t reg_end
= hva
+ mem
->memory_size
;
1791 bool writable
= !(mem
->flags
& KVM_MEM_READONLY
);
1794 if (change
!= KVM_MR_CREATE
&& change
!= KVM_MR_MOVE
&&
1795 change
!= KVM_MR_FLAGS_ONLY
)
1799 * Prevent userspace from creating a memory region outside of the IPA
1800 * space addressable by the KVM guest IPA space.
1802 if (memslot
->base_gfn
+ memslot
->npages
>=
1803 (KVM_PHYS_SIZE
>> PAGE_SHIFT
))
1806 down_read(¤t
->mm
->mmap_sem
);
1808 * A memory region could potentially cover multiple VMAs, and any holes
1809 * between them, so iterate over all of them to find out if we can map
1810 * any of them right now.
1812 * +--------------------------------------------+
1813 * +---------------+----------------+ +----------------+
1814 * | : VMA 1 | VMA 2 | | VMA 3 : |
1815 * +---------------+----------------+ +----------------+
1817 * +--------------------------------------------+
1820 struct vm_area_struct
*vma
= find_vma(current
->mm
, hva
);
1821 hva_t vm_start
, vm_end
;
1823 if (!vma
|| vma
->vm_start
>= reg_end
)
1827 * Mapping a read-only VMA is only allowed if the
1828 * memory region is configured as read-only.
1830 if (writable
&& !(vma
->vm_flags
& VM_WRITE
)) {
1836 * Take the intersection of this VMA with the memory region
1838 vm_start
= max(hva
, vma
->vm_start
);
1839 vm_end
= min(reg_end
, vma
->vm_end
);
1841 if (vma
->vm_flags
& VM_PFNMAP
) {
1842 gpa_t gpa
= mem
->guest_phys_addr
+
1843 (vm_start
- mem
->userspace_addr
);
1846 pa
= (phys_addr_t
)vma
->vm_pgoff
<< PAGE_SHIFT
;
1847 pa
+= vm_start
- vma
->vm_start
;
1849 /* IO region dirty page logging not allowed */
1850 if (memslot
->flags
& KVM_MEM_LOG_DIRTY_PAGES
) {
1855 ret
= kvm_phys_addr_ioremap(kvm
, gpa
, pa
,
1862 } while (hva
< reg_end
);
1864 if (change
== KVM_MR_FLAGS_ONLY
)
1867 spin_lock(&kvm
->mmu_lock
);
1869 unmap_stage2_range(kvm
, mem
->guest_phys_addr
, mem
->memory_size
);
1871 stage2_flush_memslot(kvm
, memslot
);
1872 spin_unlock(&kvm
->mmu_lock
);
1874 up_read(¤t
->mm
->mmap_sem
);
1878 void kvm_arch_free_memslot(struct kvm
*kvm
, struct kvm_memory_slot
*free
,
1879 struct kvm_memory_slot
*dont
)
1883 int kvm_arch_create_memslot(struct kvm
*kvm
, struct kvm_memory_slot
*slot
,
1884 unsigned long npages
)
1889 void kvm_arch_memslots_updated(struct kvm
*kvm
, struct kvm_memslots
*slots
)
1893 void kvm_arch_flush_shadow_all(struct kvm
*kvm
)
1895 kvm_free_stage2_pgd(kvm
);
1898 void kvm_arch_flush_shadow_memslot(struct kvm
*kvm
,
1899 struct kvm_memory_slot
*slot
)
1901 gpa_t gpa
= slot
->base_gfn
<< PAGE_SHIFT
;
1902 phys_addr_t size
= slot
->npages
<< PAGE_SHIFT
;
1904 spin_lock(&kvm
->mmu_lock
);
1905 unmap_stage2_range(kvm
, gpa
, size
);
1906 spin_unlock(&kvm
->mmu_lock
);
1910 * See note at ARMv7 ARM B1.14.4 (TL;DR: S/W ops are not easily virtualized).
1913 * - S/W ops are local to a CPU (not broadcast)
1914 * - We have line migration behind our back (speculation)
1915 * - System caches don't support S/W at all (damn!)
1917 * In the face of the above, the best we can do is to try and convert
1918 * S/W ops to VA ops. Because the guest is not allowed to infer the
1919 * S/W to PA mapping, it can only use S/W to nuke the whole cache,
1920 * which is a rather good thing for us.
1922 * Also, it is only used when turning caches on/off ("The expected
1923 * usage of the cache maintenance instructions that operate by set/way
1924 * is associated with the cache maintenance instructions associated
1925 * with the powerdown and powerup of caches, if this is required by
1926 * the implementation.").
1928 * We use the following policy:
1930 * - If we trap a S/W operation, we enable VM trapping to detect
1931 * caches being turned on/off, and do a full clean.
1933 * - We flush the caches on both caches being turned on and off.
1935 * - Once the caches are enabled, we stop trapping VM ops.
1937 void kvm_set_way_flush(struct kvm_vcpu
*vcpu
)
1939 unsigned long hcr
= vcpu_get_hcr(vcpu
);
1942 * If this is the first time we do a S/W operation
1943 * (i.e. HCR_TVM not set) flush the whole memory, and set the
1946 * Otherwise, rely on the VM trapping to wait for the MMU +
1947 * Caches to be turned off. At that point, we'll be able to
1948 * clean the caches again.
1950 if (!(hcr
& HCR_TVM
)) {
1951 trace_kvm_set_way_flush(*vcpu_pc(vcpu
),
1952 vcpu_has_cache_enabled(vcpu
));
1953 stage2_flush_vm(vcpu
->kvm
);
1954 vcpu_set_hcr(vcpu
, hcr
| HCR_TVM
);
1958 void kvm_toggle_cache(struct kvm_vcpu
*vcpu
, bool was_enabled
)
1960 bool now_enabled
= vcpu_has_cache_enabled(vcpu
);
1963 * If switching the MMU+caches on, need to invalidate the caches.
1964 * If switching it off, need to clean the caches.
1965 * Clean + invalidate does the trick always.
1967 if (now_enabled
!= was_enabled
)
1968 stage2_flush_vm(vcpu
->kvm
);
1970 /* Caches are now on, stop trapping VM ops (until a S/W op) */
1972 vcpu_set_hcr(vcpu
, vcpu_get_hcr(vcpu
) & ~HCR_TVM
);
1974 trace_kvm_toggle_cache(*vcpu_pc(vcpu
), was_enabled
, now_enabled
);