1 // SPDX-License-Identifier: GPL-2.0-only
3 * Stand-alone page-table allocator for hyp stage-1 and guest stage-2.
4 * No bombay mix was harmed in the writing of this file.
6 * Copyright (C) 2020 Google LLC
10 #include <linux/bitfield.h>
11 #include <asm/kvm_pgtable.h>
12 #include <asm/stage2_pgtable.h>
15 #define KVM_PTE_TYPE BIT(1)
16 #define KVM_PTE_TYPE_BLOCK 0
17 #define KVM_PTE_TYPE_PAGE 1
18 #define KVM_PTE_TYPE_TABLE 1
20 #define KVM_PTE_LEAF_ATTR_LO GENMASK(11, 2)
22 #define KVM_PTE_LEAF_ATTR_LO_S1_ATTRIDX GENMASK(4, 2)
23 #define KVM_PTE_LEAF_ATTR_LO_S1_AP GENMASK(7, 6)
24 #define KVM_PTE_LEAF_ATTR_LO_S1_AP_RO 3
25 #define KVM_PTE_LEAF_ATTR_LO_S1_AP_RW 1
26 #define KVM_PTE_LEAF_ATTR_LO_S1_SH GENMASK(9, 8)
27 #define KVM_PTE_LEAF_ATTR_LO_S1_SH_IS 3
28 #define KVM_PTE_LEAF_ATTR_LO_S1_AF BIT(10)
30 #define KVM_PTE_LEAF_ATTR_LO_S2_MEMATTR GENMASK(5, 2)
31 #define KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R BIT(6)
32 #define KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W BIT(7)
33 #define KVM_PTE_LEAF_ATTR_LO_S2_SH GENMASK(9, 8)
34 #define KVM_PTE_LEAF_ATTR_LO_S2_SH_IS 3
35 #define KVM_PTE_LEAF_ATTR_LO_S2_AF BIT(10)
37 #define KVM_PTE_LEAF_ATTR_HI GENMASK(63, 51)
39 #define KVM_PTE_LEAF_ATTR_HI_SW GENMASK(58, 55)
41 #define KVM_PTE_LEAF_ATTR_HI_S1_XN BIT(54)
43 #define KVM_PTE_LEAF_ATTR_HI_S2_XN BIT(54)
45 #define KVM_PTE_LEAF_ATTR_S2_PERMS (KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R | \
46 KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W | \
47 KVM_PTE_LEAF_ATTR_HI_S2_XN)
49 #define KVM_INVALID_PTE_OWNER_MASK GENMASK(9, 2)
50 #define KVM_MAX_OWNER_ID 1
53 * Used to indicate a pte for which a 'break-before-make' sequence is in
56 #define KVM_INVALID_PTE_LOCKED BIT(10)
58 struct kvm_pgtable_walk_data {
59 struct kvm_pgtable_walker *walker;
65 static bool kvm_phys_is_valid(u64 phys)
67 return phys < BIT(id_aa64mmfr0_parange_to_phys_shift(ID_AA64MMFR0_EL1_PARANGE_MAX));
70 static bool kvm_block_mapping_supported(const struct kvm_pgtable_visit_ctx *ctx, u64 phys)
72 u64 granule = kvm_granule_size(ctx->level);
74 if (!kvm_level_supports_block_mapping(ctx->level))
77 if (granule > (ctx->end - ctx->addr))
80 if (kvm_phys_is_valid(phys) && !IS_ALIGNED(phys, granule))
83 return IS_ALIGNED(ctx->addr, granule);
86 static u32 kvm_pgtable_idx(struct kvm_pgtable_walk_data *data, u32 level)
88 u64 shift = kvm_granule_shift(level);
89 u64 mask = BIT(PAGE_SHIFT - 3) - 1;
91 return (data->addr >> shift) & mask;
94 static u32 kvm_pgd_page_idx(struct kvm_pgtable *pgt, u64 addr)
96 u64 shift = kvm_granule_shift(pgt->start_level - 1); /* May underflow */
97 u64 mask = BIT(pgt->ia_bits) - 1;
99 return (addr & mask) >> shift;
102 static u32 kvm_pgd_pages(u32 ia_bits, u32 start_level)
104 struct kvm_pgtable pgt = {
106 .start_level = start_level,
109 return kvm_pgd_page_idx(&pgt, -1ULL) + 1;
112 static bool kvm_pte_table(kvm_pte_t pte, u32 level)
114 if (level == KVM_PGTABLE_MAX_LEVELS - 1)
117 if (!kvm_pte_valid(pte))
120 return FIELD_GET(KVM_PTE_TYPE, pte) == KVM_PTE_TYPE_TABLE;
123 static kvm_pte_t *kvm_pte_follow(kvm_pte_t pte, struct kvm_pgtable_mm_ops *mm_ops)
125 return mm_ops->phys_to_virt(kvm_pte_to_phys(pte));
128 static void kvm_clear_pte(kvm_pte_t *ptep)
130 WRITE_ONCE(*ptep, 0);
133 static kvm_pte_t kvm_init_table_pte(kvm_pte_t *childp, struct kvm_pgtable_mm_ops *mm_ops)
135 kvm_pte_t pte = kvm_phys_to_pte(mm_ops->virt_to_phys(childp));
137 pte |= FIELD_PREP(KVM_PTE_TYPE, KVM_PTE_TYPE_TABLE);
138 pte |= KVM_PTE_VALID;
142 static kvm_pte_t kvm_init_valid_leaf_pte(u64 pa, kvm_pte_t attr, u32 level)
144 kvm_pte_t pte = kvm_phys_to_pte(pa);
145 u64 type = (level == KVM_PGTABLE_MAX_LEVELS - 1) ? KVM_PTE_TYPE_PAGE :
148 pte |= attr & (KVM_PTE_LEAF_ATTR_LO | KVM_PTE_LEAF_ATTR_HI);
149 pte |= FIELD_PREP(KVM_PTE_TYPE, type);
150 pte |= KVM_PTE_VALID;
155 static kvm_pte_t kvm_init_invalid_leaf_owner(u8 owner_id)
157 return FIELD_PREP(KVM_INVALID_PTE_OWNER_MASK, owner_id);
160 static int kvm_pgtable_visitor_cb(struct kvm_pgtable_walk_data *data,
161 const struct kvm_pgtable_visit_ctx *ctx,
162 enum kvm_pgtable_walk_flags visit)
164 struct kvm_pgtable_walker *walker = data->walker;
166 /* Ensure the appropriate lock is held (e.g. RCU lock for stage-2 MMU) */
167 WARN_ON_ONCE(kvm_pgtable_walk_shared(ctx) && !kvm_pgtable_walk_lock_held());
168 return walker->cb(ctx, visit);
171 static bool kvm_pgtable_walk_continue(const struct kvm_pgtable_walker *walker,
175 * Visitor callbacks return EAGAIN when the conditions that led to a
176 * fault are no longer reflected in the page tables due to a race to
177 * update a PTE. In the context of a fault handler this is interpreted
178 * as a signal to retry guest execution.
180 * Ignore the return code altogether for walkers outside a fault handler
181 * (e.g. write protecting a range of memory) and chug along with the
185 return !(walker->flags & KVM_PGTABLE_WALK_HANDLE_FAULT);
190 static int __kvm_pgtable_walk(struct kvm_pgtable_walk_data *data,
191 struct kvm_pgtable_mm_ops *mm_ops, kvm_pteref_t pgtable, u32 level);
193 static inline int __kvm_pgtable_visit(struct kvm_pgtable_walk_data *data,
194 struct kvm_pgtable_mm_ops *mm_ops,
195 kvm_pteref_t pteref, u32 level)
197 enum kvm_pgtable_walk_flags flags = data->walker->flags;
198 kvm_pte_t *ptep = kvm_dereference_pteref(data->walker, pteref);
199 struct kvm_pgtable_visit_ctx ctx = {
201 .old = READ_ONCE(*ptep),
202 .arg = data->walker->arg,
211 bool table = kvm_pte_table(ctx.old, level);
213 if (table && (ctx.flags & KVM_PGTABLE_WALK_TABLE_PRE))
214 ret = kvm_pgtable_visitor_cb(data, &ctx, KVM_PGTABLE_WALK_TABLE_PRE);
216 if (!table && (ctx.flags & KVM_PGTABLE_WALK_LEAF)) {
217 ret = kvm_pgtable_visitor_cb(data, &ctx, KVM_PGTABLE_WALK_LEAF);
218 ctx.old = READ_ONCE(*ptep);
219 table = kvm_pte_table(ctx.old, level);
222 if (!kvm_pgtable_walk_continue(data->walker, ret))
226 data->addr = ALIGN_DOWN(data->addr, kvm_granule_size(level));
227 data->addr += kvm_granule_size(level);
231 childp = (kvm_pteref_t)kvm_pte_follow(ctx.old, mm_ops);
232 ret = __kvm_pgtable_walk(data, mm_ops, childp, level + 1);
233 if (!kvm_pgtable_walk_continue(data->walker, ret))
236 if (ctx.flags & KVM_PGTABLE_WALK_TABLE_POST)
237 ret = kvm_pgtable_visitor_cb(data, &ctx, KVM_PGTABLE_WALK_TABLE_POST);
240 if (kvm_pgtable_walk_continue(data->walker, ret))
246 static int __kvm_pgtable_walk(struct kvm_pgtable_walk_data *data,
247 struct kvm_pgtable_mm_ops *mm_ops, kvm_pteref_t pgtable, u32 level)
252 if (WARN_ON_ONCE(level >= KVM_PGTABLE_MAX_LEVELS))
255 for (idx = kvm_pgtable_idx(data, level); idx < PTRS_PER_PTE; ++idx) {
256 kvm_pteref_t pteref = &pgtable[idx];
258 if (data->addr >= data->end)
261 ret = __kvm_pgtable_visit(data, mm_ops, pteref, level);
269 static int _kvm_pgtable_walk(struct kvm_pgtable *pgt, struct kvm_pgtable_walk_data *data)
273 u64 limit = BIT(pgt->ia_bits);
275 if (data->addr > limit || data->end > limit)
281 for (idx = kvm_pgd_page_idx(pgt, data->addr); data->addr < data->end; ++idx) {
282 kvm_pteref_t pteref = &pgt->pgd[idx * PTRS_PER_PTE];
284 ret = __kvm_pgtable_walk(data, pgt->mm_ops, pteref, pgt->start_level);
292 int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size,
293 struct kvm_pgtable_walker *walker)
295 struct kvm_pgtable_walk_data walk_data = {
296 .addr = ALIGN_DOWN(addr, PAGE_SIZE),
297 .end = PAGE_ALIGN(walk_data.addr + size),
302 r = kvm_pgtable_walk_begin(walker);
306 r = _kvm_pgtable_walk(pgt, &walk_data);
307 kvm_pgtable_walk_end(walker);
312 struct leaf_walk_data {
317 static int leaf_walker(const struct kvm_pgtable_visit_ctx *ctx,
318 enum kvm_pgtable_walk_flags visit)
320 struct leaf_walk_data *data = ctx->arg;
322 data->pte = ctx->old;
323 data->level = ctx->level;
328 int kvm_pgtable_get_leaf(struct kvm_pgtable *pgt, u64 addr,
329 kvm_pte_t *ptep, u32 *level)
331 struct leaf_walk_data data;
332 struct kvm_pgtable_walker walker = {
334 .flags = KVM_PGTABLE_WALK_LEAF,
339 ret = kvm_pgtable_walk(pgt, ALIGN_DOWN(addr, PAGE_SIZE),
351 struct hyp_map_data {
356 static int hyp_set_prot_attr(enum kvm_pgtable_prot prot, kvm_pte_t *ptep)
358 bool device = prot & KVM_PGTABLE_PROT_DEVICE;
359 u32 mtype = device ? MT_DEVICE_nGnRE : MT_NORMAL;
360 kvm_pte_t attr = FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S1_ATTRIDX, mtype);
361 u32 sh = KVM_PTE_LEAF_ATTR_LO_S1_SH_IS;
362 u32 ap = (prot & KVM_PGTABLE_PROT_W) ? KVM_PTE_LEAF_ATTR_LO_S1_AP_RW :
363 KVM_PTE_LEAF_ATTR_LO_S1_AP_RO;
365 if (!(prot & KVM_PGTABLE_PROT_R))
368 if (prot & KVM_PGTABLE_PROT_X) {
369 if (prot & KVM_PGTABLE_PROT_W)
375 attr |= KVM_PTE_LEAF_ATTR_HI_S1_XN;
378 attr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S1_AP, ap);
379 attr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S1_SH, sh);
380 attr |= KVM_PTE_LEAF_ATTR_LO_S1_AF;
381 attr |= prot & KVM_PTE_LEAF_ATTR_HI_SW;
387 enum kvm_pgtable_prot kvm_pgtable_hyp_pte_prot(kvm_pte_t pte)
389 enum kvm_pgtable_prot prot = pte & KVM_PTE_LEAF_ATTR_HI_SW;
392 if (!kvm_pte_valid(pte))
395 if (!(pte & KVM_PTE_LEAF_ATTR_HI_S1_XN))
396 prot |= KVM_PGTABLE_PROT_X;
398 ap = FIELD_GET(KVM_PTE_LEAF_ATTR_LO_S1_AP, pte);
399 if (ap == KVM_PTE_LEAF_ATTR_LO_S1_AP_RO)
400 prot |= KVM_PGTABLE_PROT_R;
401 else if (ap == KVM_PTE_LEAF_ATTR_LO_S1_AP_RW)
402 prot |= KVM_PGTABLE_PROT_RW;
407 static bool hyp_map_walker_try_leaf(const struct kvm_pgtable_visit_ctx *ctx,
408 struct hyp_map_data *data)
411 u64 granule = kvm_granule_size(ctx->level), phys = data->phys;
413 if (!kvm_block_mapping_supported(ctx, phys))
416 data->phys += granule;
417 new = kvm_init_valid_leaf_pte(phys, data->attr, ctx->level);
420 if (!kvm_pte_valid(ctx->old))
421 ctx->mm_ops->get_page(ctx->ptep);
422 else if (WARN_ON((ctx->old ^ new) & ~KVM_PTE_LEAF_ATTR_HI_SW))
425 smp_store_release(ctx->ptep, new);
429 static int hyp_map_walker(const struct kvm_pgtable_visit_ctx *ctx,
430 enum kvm_pgtable_walk_flags visit)
432 kvm_pte_t *childp, new;
433 struct hyp_map_data *data = ctx->arg;
434 struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
436 if (hyp_map_walker_try_leaf(ctx, data))
439 if (WARN_ON(ctx->level == KVM_PGTABLE_MAX_LEVELS - 1))
442 childp = (kvm_pte_t *)mm_ops->zalloc_page(NULL);
446 new = kvm_init_table_pte(childp, mm_ops);
447 mm_ops->get_page(ctx->ptep);
448 smp_store_release(ctx->ptep, new);
453 int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys,
454 enum kvm_pgtable_prot prot)
457 struct hyp_map_data map_data = {
458 .phys = ALIGN_DOWN(phys, PAGE_SIZE),
460 struct kvm_pgtable_walker walker = {
461 .cb = hyp_map_walker,
462 .flags = KVM_PGTABLE_WALK_LEAF,
466 ret = hyp_set_prot_attr(prot, &map_data.attr);
470 ret = kvm_pgtable_walk(pgt, addr, size, &walker);
476 static int hyp_unmap_walker(const struct kvm_pgtable_visit_ctx *ctx,
477 enum kvm_pgtable_walk_flags visit)
479 kvm_pte_t *childp = NULL;
480 u64 granule = kvm_granule_size(ctx->level);
481 u64 *unmapped = ctx->arg;
482 struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
484 if (!kvm_pte_valid(ctx->old))
487 if (kvm_pte_table(ctx->old, ctx->level)) {
488 childp = kvm_pte_follow(ctx->old, mm_ops);
490 if (mm_ops->page_count(childp) != 1)
493 kvm_clear_pte(ctx->ptep);
495 __tlbi_level(vae2is, __TLBI_VADDR(ctx->addr, 0), ctx->level);
497 if (ctx->end - ctx->addr < granule)
500 kvm_clear_pte(ctx->ptep);
502 __tlbi_level(vale2is, __TLBI_VADDR(ctx->addr, 0), ctx->level);
503 *unmapped += granule;
508 mm_ops->put_page(ctx->ptep);
511 mm_ops->put_page(childp);
516 u64 kvm_pgtable_hyp_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size)
519 struct kvm_pgtable_walker walker = {
520 .cb = hyp_unmap_walker,
522 .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST,
525 if (!pgt->mm_ops->page_count)
528 kvm_pgtable_walk(pgt, addr, size, &walker);
532 int kvm_pgtable_hyp_init(struct kvm_pgtable *pgt, u32 va_bits,
533 struct kvm_pgtable_mm_ops *mm_ops)
535 u64 levels = ARM64_HW_PGTABLE_LEVELS(va_bits);
537 pgt->pgd = (kvm_pteref_t)mm_ops->zalloc_page(NULL);
541 pgt->ia_bits = va_bits;
542 pgt->start_level = KVM_PGTABLE_MAX_LEVELS - levels;
543 pgt->mm_ops = mm_ops;
545 pgt->force_pte_cb = NULL;
550 static int hyp_free_walker(const struct kvm_pgtable_visit_ctx *ctx,
551 enum kvm_pgtable_walk_flags visit)
553 struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
555 if (!kvm_pte_valid(ctx->old))
558 mm_ops->put_page(ctx->ptep);
560 if (kvm_pte_table(ctx->old, ctx->level))
561 mm_ops->put_page(kvm_pte_follow(ctx->old, mm_ops));
566 void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt)
568 struct kvm_pgtable_walker walker = {
569 .cb = hyp_free_walker,
570 .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST,
573 WARN_ON(kvm_pgtable_walk(pgt, 0, BIT(pgt->ia_bits), &walker));
574 pgt->mm_ops->put_page(kvm_dereference_pteref(&walker, pgt->pgd));
578 struct stage2_map_data {
586 struct kvm_s2_mmu *mmu;
589 /* Force mappings to page granularity */
593 u64 kvm_get_vtcr(u64 mmfr0, u64 mmfr1, u32 phys_shift)
595 u64 vtcr = VTCR_EL2_FLAGS;
598 vtcr |= kvm_get_parange(mmfr0) << VTCR_EL2_PS_SHIFT;
599 vtcr |= VTCR_EL2_T0SZ(phys_shift);
601 * Use a minimum 2 level page table to prevent splitting
602 * host PMD huge pages at stage2.
604 lvls = stage2_pgtable_levels(phys_shift);
607 vtcr |= VTCR_EL2_LVLS_TO_SL0(lvls);
609 #ifdef CONFIG_ARM64_HW_AFDBM
611 * Enable the Hardware Access Flag management, unconditionally
612 * on all CPUs. The features is RES0 on CPUs without the support
613 * and must be ignored by the CPUs.
616 #endif /* CONFIG_ARM64_HW_AFDBM */
618 /* Set the vmid bits */
619 vtcr |= (get_vmid_bits(mmfr1) == 16) ?
626 static bool stage2_has_fwb(struct kvm_pgtable *pgt)
628 if (!cpus_have_const_cap(ARM64_HAS_STAGE2_FWB))
631 return !(pgt->flags & KVM_PGTABLE_S2_NOFWB);
634 #define KVM_S2_MEMATTR(pgt, attr) PAGE_S2_MEMATTR(attr, stage2_has_fwb(pgt))
636 static int stage2_set_prot_attr(struct kvm_pgtable *pgt, enum kvm_pgtable_prot prot,
639 bool device = prot & KVM_PGTABLE_PROT_DEVICE;
640 kvm_pte_t attr = device ? KVM_S2_MEMATTR(pgt, DEVICE_nGnRE) :
641 KVM_S2_MEMATTR(pgt, NORMAL);
642 u32 sh = KVM_PTE_LEAF_ATTR_LO_S2_SH_IS;
644 if (!(prot & KVM_PGTABLE_PROT_X))
645 attr |= KVM_PTE_LEAF_ATTR_HI_S2_XN;
649 if (prot & KVM_PGTABLE_PROT_R)
650 attr |= KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R;
652 if (prot & KVM_PGTABLE_PROT_W)
653 attr |= KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W;
655 attr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S2_SH, sh);
656 attr |= KVM_PTE_LEAF_ATTR_LO_S2_AF;
657 attr |= prot & KVM_PTE_LEAF_ATTR_HI_SW;
663 enum kvm_pgtable_prot kvm_pgtable_stage2_pte_prot(kvm_pte_t pte)
665 enum kvm_pgtable_prot prot = pte & KVM_PTE_LEAF_ATTR_HI_SW;
667 if (!kvm_pte_valid(pte))
670 if (pte & KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R)
671 prot |= KVM_PGTABLE_PROT_R;
672 if (pte & KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W)
673 prot |= KVM_PGTABLE_PROT_W;
674 if (!(pte & KVM_PTE_LEAF_ATTR_HI_S2_XN))
675 prot |= KVM_PGTABLE_PROT_X;
680 static bool stage2_pte_needs_update(kvm_pte_t old, kvm_pte_t new)
682 if (!kvm_pte_valid(old) || !kvm_pte_valid(new))
685 return ((old ^ new) & (~KVM_PTE_LEAF_ATTR_S2_PERMS));
688 static bool stage2_pte_is_counted(kvm_pte_t pte)
691 * The refcount tracks valid entries as well as invalid entries if they
692 * encode ownership of a page to another entity than the page-table
693 * owner, whose id is 0.
698 static bool stage2_pte_is_locked(kvm_pte_t pte)
700 return !kvm_pte_valid(pte) && (pte & KVM_INVALID_PTE_LOCKED);
703 static bool stage2_try_set_pte(const struct kvm_pgtable_visit_ctx *ctx, kvm_pte_t new)
705 if (!kvm_pgtable_walk_shared(ctx)) {
706 WRITE_ONCE(*ctx->ptep, new);
710 return cmpxchg(ctx->ptep, ctx->old, new) == ctx->old;
714 * stage2_try_break_pte() - Invalidates a pte according to the
715 * 'break-before-make' requirements of the
718 * @ctx: context of the visited pte.
721 * Returns: true if the pte was successfully broken.
723 * If the removed pte was valid, performs the necessary serialization and TLB
724 * invalidation for the old value. For counted ptes, drops the reference count
725 * on the containing table page.
727 static bool stage2_try_break_pte(const struct kvm_pgtable_visit_ctx *ctx,
728 struct kvm_s2_mmu *mmu)
730 struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
732 if (stage2_pte_is_locked(ctx->old)) {
734 * Should never occur if this walker has exclusive access to the
737 WARN_ON(!kvm_pgtable_walk_shared(ctx));
741 if (!stage2_try_set_pte(ctx, KVM_INVALID_PTE_LOCKED))
745 * Perform the appropriate TLB invalidation based on the evicted pte
748 if (kvm_pte_table(ctx->old, ctx->level))
749 kvm_call_hyp(__kvm_tlb_flush_vmid, mmu);
750 else if (kvm_pte_valid(ctx->old))
751 kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu, ctx->addr, ctx->level);
753 if (stage2_pte_is_counted(ctx->old))
754 mm_ops->put_page(ctx->ptep);
759 static void stage2_make_pte(const struct kvm_pgtable_visit_ctx *ctx, kvm_pte_t new)
761 struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
763 WARN_ON(!stage2_pte_is_locked(*ctx->ptep));
765 if (stage2_pte_is_counted(new))
766 mm_ops->get_page(ctx->ptep);
768 smp_store_release(ctx->ptep, new);
771 static void stage2_put_pte(const struct kvm_pgtable_visit_ctx *ctx, struct kvm_s2_mmu *mmu,
772 struct kvm_pgtable_mm_ops *mm_ops)
775 * Clear the existing PTE, and perform break-before-make with
776 * TLB maintenance if it was valid.
778 if (kvm_pte_valid(ctx->old)) {
779 kvm_clear_pte(ctx->ptep);
780 kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu, ctx->addr, ctx->level);
783 mm_ops->put_page(ctx->ptep);
786 static bool stage2_pte_cacheable(struct kvm_pgtable *pgt, kvm_pte_t pte)
788 u64 memattr = pte & KVM_PTE_LEAF_ATTR_LO_S2_MEMATTR;
789 return memattr == KVM_S2_MEMATTR(pgt, NORMAL);
792 static bool stage2_pte_executable(kvm_pte_t pte)
794 return !(pte & KVM_PTE_LEAF_ATTR_HI_S2_XN);
797 static bool stage2_leaf_mapping_allowed(const struct kvm_pgtable_visit_ctx *ctx,
798 struct stage2_map_data *data)
800 if (data->force_pte && (ctx->level < (KVM_PGTABLE_MAX_LEVELS - 1)))
803 return kvm_block_mapping_supported(ctx, data->phys);
806 static int stage2_map_walker_try_leaf(const struct kvm_pgtable_visit_ctx *ctx,
807 struct stage2_map_data *data)
810 u64 granule = kvm_granule_size(ctx->level), phys = data->phys;
811 struct kvm_pgtable *pgt = data->mmu->pgt;
812 struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
814 if (!stage2_leaf_mapping_allowed(ctx, data))
817 if (kvm_phys_is_valid(phys))
818 new = kvm_init_valid_leaf_pte(phys, data->attr, ctx->level);
820 new = kvm_init_invalid_leaf_owner(data->owner_id);
823 * Skip updating the PTE if we are trying to recreate the exact
824 * same mapping or only change the access permissions. Instead,
825 * the vCPU will exit one more time from guest if still needed
826 * and then go through the path of relaxing permissions.
828 if (!stage2_pte_needs_update(ctx->old, new))
831 if (!stage2_try_break_pte(ctx, data->mmu))
834 /* Perform CMOs before installation of the guest stage-2 PTE */
835 if (mm_ops->dcache_clean_inval_poc && stage2_pte_cacheable(pgt, new))
836 mm_ops->dcache_clean_inval_poc(kvm_pte_follow(new, mm_ops),
839 if (mm_ops->icache_inval_pou && stage2_pte_executable(new))
840 mm_ops->icache_inval_pou(kvm_pte_follow(new, mm_ops), granule);
842 stage2_make_pte(ctx, new);
844 if (kvm_phys_is_valid(phys))
845 data->phys += granule;
849 static int stage2_map_walk_table_pre(const struct kvm_pgtable_visit_ctx *ctx,
850 struct stage2_map_data *data)
852 struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
853 kvm_pte_t *childp = kvm_pte_follow(ctx->old, mm_ops);
856 if (!stage2_leaf_mapping_allowed(ctx, data))
859 ret = stage2_map_walker_try_leaf(ctx, data);
863 mm_ops->free_removed_table(childp, ctx->level);
867 static int stage2_map_walk_leaf(const struct kvm_pgtable_visit_ctx *ctx,
868 struct stage2_map_data *data)
870 struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
871 kvm_pte_t *childp, new;
874 ret = stage2_map_walker_try_leaf(ctx, data);
878 if (WARN_ON(ctx->level == KVM_PGTABLE_MAX_LEVELS - 1))
884 childp = mm_ops->zalloc_page(data->memcache);
888 if (!stage2_try_break_pte(ctx, data->mmu)) {
889 mm_ops->put_page(childp);
894 * If we've run into an existing block mapping then replace it with
895 * a table. Accesses beyond 'end' that fall within the new table
896 * will be mapped lazily.
898 new = kvm_init_table_pte(childp, mm_ops);
899 stage2_make_pte(ctx, new);
905 * The TABLE_PRE callback runs for table entries on the way down, looking
906 * for table entries which we could conceivably replace with a block entry
907 * for this mapping. If it finds one it replaces the entry and calls
908 * kvm_pgtable_mm_ops::free_removed_table() to tear down the detached table.
910 * Otherwise, the LEAF callback performs the mapping at the existing leaves
913 static int stage2_map_walker(const struct kvm_pgtable_visit_ctx *ctx,
914 enum kvm_pgtable_walk_flags visit)
916 struct stage2_map_data *data = ctx->arg;
919 case KVM_PGTABLE_WALK_TABLE_PRE:
920 return stage2_map_walk_table_pre(ctx, data);
921 case KVM_PGTABLE_WALK_LEAF:
922 return stage2_map_walk_leaf(ctx, data);
928 int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size,
929 u64 phys, enum kvm_pgtable_prot prot,
930 void *mc, enum kvm_pgtable_walk_flags flags)
933 struct stage2_map_data map_data = {
934 .phys = ALIGN_DOWN(phys, PAGE_SIZE),
937 .force_pte = pgt->force_pte_cb && pgt->force_pte_cb(addr, addr + size, prot),
939 struct kvm_pgtable_walker walker = {
940 .cb = stage2_map_walker,
942 KVM_PGTABLE_WALK_TABLE_PRE |
943 KVM_PGTABLE_WALK_LEAF,
947 if (WARN_ON((pgt->flags & KVM_PGTABLE_S2_IDMAP) && (addr != phys)))
950 ret = stage2_set_prot_attr(pgt, prot, &map_data.attr);
954 ret = kvm_pgtable_walk(pgt, addr, size, &walker);
959 int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size,
960 void *mc, u8 owner_id)
963 struct stage2_map_data map_data = {
964 .phys = KVM_PHYS_INVALID,
967 .owner_id = owner_id,
970 struct kvm_pgtable_walker walker = {
971 .cb = stage2_map_walker,
972 .flags = KVM_PGTABLE_WALK_TABLE_PRE |
973 KVM_PGTABLE_WALK_LEAF,
977 if (owner_id > KVM_MAX_OWNER_ID)
980 ret = kvm_pgtable_walk(pgt, addr, size, &walker);
984 static int stage2_unmap_walker(const struct kvm_pgtable_visit_ctx *ctx,
985 enum kvm_pgtable_walk_flags visit)
987 struct kvm_pgtable *pgt = ctx->arg;
988 struct kvm_s2_mmu *mmu = pgt->mmu;
989 struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
990 kvm_pte_t *childp = NULL;
991 bool need_flush = false;
993 if (!kvm_pte_valid(ctx->old)) {
994 if (stage2_pte_is_counted(ctx->old)) {
995 kvm_clear_pte(ctx->ptep);
996 mm_ops->put_page(ctx->ptep);
1001 if (kvm_pte_table(ctx->old, ctx->level)) {
1002 childp = kvm_pte_follow(ctx->old, mm_ops);
1004 if (mm_ops->page_count(childp) != 1)
1006 } else if (stage2_pte_cacheable(pgt, ctx->old)) {
1007 need_flush = !stage2_has_fwb(pgt);
1011 * This is similar to the map() path in that we unmap the entire
1012 * block entry and rely on the remaining portions being faulted
1015 stage2_put_pte(ctx, mmu, mm_ops);
1017 if (need_flush && mm_ops->dcache_clean_inval_poc)
1018 mm_ops->dcache_clean_inval_poc(kvm_pte_follow(ctx->old, mm_ops),
1019 kvm_granule_size(ctx->level));
1022 mm_ops->put_page(childp);
1027 int kvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size)
1029 struct kvm_pgtable_walker walker = {
1030 .cb = stage2_unmap_walker,
1032 .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST,
1035 return kvm_pgtable_walk(pgt, addr, size, &walker);
1038 struct stage2_attr_data {
1045 static int stage2_attr_walker(const struct kvm_pgtable_visit_ctx *ctx,
1046 enum kvm_pgtable_walk_flags visit)
1048 kvm_pte_t pte = ctx->old;
1049 struct stage2_attr_data *data = ctx->arg;
1050 struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
1052 if (!kvm_pte_valid(ctx->old))
1055 data->level = ctx->level;
1057 pte &= ~data->attr_clr;
1058 pte |= data->attr_set;
1061 * We may race with the CPU trying to set the access flag here,
1062 * but worst-case the access flag update gets lost and will be
1063 * set on the next access instead.
1065 if (data->pte != pte) {
1067 * Invalidate instruction cache before updating the guest
1068 * stage-2 PTE if we are going to add executable permission.
1070 if (mm_ops->icache_inval_pou &&
1071 stage2_pte_executable(pte) && !stage2_pte_executable(ctx->old))
1072 mm_ops->icache_inval_pou(kvm_pte_follow(pte, mm_ops),
1073 kvm_granule_size(ctx->level));
1075 if (!stage2_try_set_pte(ctx, pte))
1082 static int stage2_update_leaf_attrs(struct kvm_pgtable *pgt, u64 addr,
1083 u64 size, kvm_pte_t attr_set,
1084 kvm_pte_t attr_clr, kvm_pte_t *orig_pte,
1085 u32 *level, enum kvm_pgtable_walk_flags flags)
1088 kvm_pte_t attr_mask = KVM_PTE_LEAF_ATTR_LO | KVM_PTE_LEAF_ATTR_HI;
1089 struct stage2_attr_data data = {
1090 .attr_set = attr_set & attr_mask,
1091 .attr_clr = attr_clr & attr_mask,
1093 struct kvm_pgtable_walker walker = {
1094 .cb = stage2_attr_walker,
1096 .flags = flags | KVM_PGTABLE_WALK_LEAF,
1099 ret = kvm_pgtable_walk(pgt, addr, size, &walker);
1104 *orig_pte = data.pte;
1107 *level = data.level;
1111 int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size)
1113 return stage2_update_leaf_attrs(pgt, addr, size, 0,
1114 KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W,
1118 kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr)
1123 ret = stage2_update_leaf_attrs(pgt, addr, 1, KVM_PTE_LEAF_ATTR_LO_S2_AF, 0,
1125 KVM_PGTABLE_WALK_HANDLE_FAULT |
1126 KVM_PGTABLE_WALK_SHARED);
1133 kvm_pte_t kvm_pgtable_stage2_mkold(struct kvm_pgtable *pgt, u64 addr)
1136 stage2_update_leaf_attrs(pgt, addr, 1, 0, KVM_PTE_LEAF_ATTR_LO_S2_AF,
1139 * "But where's the TLBI?!", you scream.
1140 * "Over in the core code", I sigh.
1142 * See the '->clear_flush_young()' callback on the KVM mmu notifier.
1147 bool kvm_pgtable_stage2_is_young(struct kvm_pgtable *pgt, u64 addr)
1150 stage2_update_leaf_attrs(pgt, addr, 1, 0, 0, &pte, NULL, 0);
1151 return pte & KVM_PTE_LEAF_ATTR_LO_S2_AF;
1154 int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr,
1155 enum kvm_pgtable_prot prot)
1159 kvm_pte_t set = 0, clr = 0;
1161 if (prot & KVM_PTE_LEAF_ATTR_HI_SW)
1164 if (prot & KVM_PGTABLE_PROT_R)
1165 set |= KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R;
1167 if (prot & KVM_PGTABLE_PROT_W)
1168 set |= KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W;
1170 if (prot & KVM_PGTABLE_PROT_X)
1171 clr |= KVM_PTE_LEAF_ATTR_HI_S2_XN;
1173 ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, NULL, &level,
1174 KVM_PGTABLE_WALK_HANDLE_FAULT |
1175 KVM_PGTABLE_WALK_SHARED);
1177 kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, pgt->mmu, addr, level);
1181 static int stage2_flush_walker(const struct kvm_pgtable_visit_ctx *ctx,
1182 enum kvm_pgtable_walk_flags visit)
1184 struct kvm_pgtable *pgt = ctx->arg;
1185 struct kvm_pgtable_mm_ops *mm_ops = pgt->mm_ops;
1187 if (!kvm_pte_valid(ctx->old) || !stage2_pte_cacheable(pgt, ctx->old))
1190 if (mm_ops->dcache_clean_inval_poc)
1191 mm_ops->dcache_clean_inval_poc(kvm_pte_follow(ctx->old, mm_ops),
1192 kvm_granule_size(ctx->level));
1196 int kvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size)
1198 struct kvm_pgtable_walker walker = {
1199 .cb = stage2_flush_walker,
1200 .flags = KVM_PGTABLE_WALK_LEAF,
1204 if (stage2_has_fwb(pgt))
1207 return kvm_pgtable_walk(pgt, addr, size, &walker);
1211 int __kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu,
1212 struct kvm_pgtable_mm_ops *mm_ops,
1213 enum kvm_pgtable_stage2_flags flags,
1214 kvm_pgtable_force_pte_cb_t force_pte_cb)
1217 u64 vtcr = mmu->arch->vtcr;
1218 u32 ia_bits = VTCR_EL2_IPA(vtcr);
1219 u32 sl0 = FIELD_GET(VTCR_EL2_SL0_MASK, vtcr);
1220 u32 start_level = VTCR_EL2_TGRAN_SL0_BASE - sl0;
1222 pgd_sz = kvm_pgd_pages(ia_bits, start_level) * PAGE_SIZE;
1223 pgt->pgd = (kvm_pteref_t)mm_ops->zalloc_pages_exact(pgd_sz);
1227 pgt->ia_bits = ia_bits;
1228 pgt->start_level = start_level;
1229 pgt->mm_ops = mm_ops;
1232 pgt->force_pte_cb = force_pte_cb;
1234 /* Ensure zeroed PGD pages are visible to the hardware walker */
1239 size_t kvm_pgtable_stage2_pgd_size(u64 vtcr)
1241 u32 ia_bits = VTCR_EL2_IPA(vtcr);
1242 u32 sl0 = FIELD_GET(VTCR_EL2_SL0_MASK, vtcr);
1243 u32 start_level = VTCR_EL2_TGRAN_SL0_BASE - sl0;
1245 return kvm_pgd_pages(ia_bits, start_level) * PAGE_SIZE;
1248 static int stage2_free_walker(const struct kvm_pgtable_visit_ctx *ctx,
1249 enum kvm_pgtable_walk_flags visit)
1251 struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
1253 if (!stage2_pte_is_counted(ctx->old))
1256 mm_ops->put_page(ctx->ptep);
1258 if (kvm_pte_table(ctx->old, ctx->level))
1259 mm_ops->put_page(kvm_pte_follow(ctx->old, mm_ops));
1264 void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt)
1267 struct kvm_pgtable_walker walker = {
1268 .cb = stage2_free_walker,
1269 .flags = KVM_PGTABLE_WALK_LEAF |
1270 KVM_PGTABLE_WALK_TABLE_POST,
1273 WARN_ON(kvm_pgtable_walk(pgt, 0, BIT(pgt->ia_bits), &walker));
1274 pgd_sz = kvm_pgd_pages(pgt->ia_bits, pgt->start_level) * PAGE_SIZE;
1275 pgt->mm_ops->free_pages_exact(kvm_dereference_pteref(&walker, pgt->pgd), pgd_sz);
1279 void kvm_pgtable_stage2_free_removed(struct kvm_pgtable_mm_ops *mm_ops, void *pgtable, u32 level)
1281 kvm_pteref_t ptep = (kvm_pteref_t)pgtable;
1282 struct kvm_pgtable_walker walker = {
1283 .cb = stage2_free_walker,
1284 .flags = KVM_PGTABLE_WALK_LEAF |
1285 KVM_PGTABLE_WALK_TABLE_POST,
1287 struct kvm_pgtable_walk_data data = {
1291 * At this point the IPA really doesn't matter, as the page
1292 * table being traversed has already been removed from the stage
1293 * 2. Set an appropriate range to cover the entire page table.
1296 .end = kvm_granule_size(level),
1299 WARN_ON(__kvm_pgtable_walk(&data, mm_ops, ptep, level + 1));