diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/pgtable.c')
| -rw-r--r-- | arch/arm64/kvm/hyp/pgtable.c | 1469 |
1 files changed, 985 insertions, 484 deletions
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index 05321f4165e3..947ac1a951a5 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -11,100 +11,41 @@ #include <asm/kvm_pgtable.h> #include <asm/stage2_pgtable.h> -#define KVM_PTE_VALID BIT(0) - -#define KVM_PTE_TYPE BIT(1) -#define KVM_PTE_TYPE_BLOCK 0 -#define KVM_PTE_TYPE_PAGE 1 -#define KVM_PTE_TYPE_TABLE 1 - -#define KVM_PTE_ADDR_MASK GENMASK(47, PAGE_SHIFT) -#define KVM_PTE_ADDR_51_48 GENMASK(15, 12) - -#define KVM_PTE_LEAF_ATTR_LO GENMASK(11, 2) - -#define KVM_PTE_LEAF_ATTR_LO_S1_ATTRIDX GENMASK(4, 2) -#define KVM_PTE_LEAF_ATTR_LO_S1_AP GENMASK(7, 6) -#define KVM_PTE_LEAF_ATTR_LO_S1_AP_RO 3 -#define KVM_PTE_LEAF_ATTR_LO_S1_AP_RW 1 -#define KVM_PTE_LEAF_ATTR_LO_S1_SH GENMASK(9, 8) -#define KVM_PTE_LEAF_ATTR_LO_S1_SH_IS 3 -#define KVM_PTE_LEAF_ATTR_LO_S1_AF BIT(10) - -#define KVM_PTE_LEAF_ATTR_LO_S2_MEMATTR GENMASK(5, 2) -#define KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R BIT(6) -#define KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W BIT(7) -#define KVM_PTE_LEAF_ATTR_LO_S2_SH GENMASK(9, 8) -#define KVM_PTE_LEAF_ATTR_LO_S2_SH_IS 3 -#define KVM_PTE_LEAF_ATTR_LO_S2_AF BIT(10) - -#define KVM_PTE_LEAF_ATTR_HI GENMASK(63, 51) - -#define KVM_PTE_LEAF_ATTR_HI_S1_XN BIT(54) - -#define KVM_PTE_LEAF_ATTR_HI_S2_XN BIT(54) - -#define KVM_PTE_LEAF_ATTR_S2_PERMS (KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R | \ - KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W | \ - KVM_PTE_LEAF_ATTR_HI_S2_XN) - -#define KVM_PTE_LEAF_ATTR_S2_IGNORED GENMASK(58, 55) - -#define KVM_INVALID_PTE_OWNER_MASK GENMASK(63, 56) -#define KVM_MAX_OWNER_ID 1 - struct kvm_pgtable_walk_data { - struct kvm_pgtable *pgt; struct kvm_pgtable_walker *walker; + const u64 start; u64 addr; - u64 end; + const u64 end; }; -static u64 kvm_granule_shift(u32 level) -{ - /* Assumes KVM_PGTABLE_MAX_LEVELS is 4 */ - return ARM64_HW_PGTABLE_LEVEL_SHIFT(level); -} - -static u64 kvm_granule_size(u32 level) +static bool kvm_pgtable_walk_skip_bbm_tlbi(const struct kvm_pgtable_visit_ctx *ctx) { - return BIT(kvm_granule_shift(level)); + return unlikely(ctx->flags & KVM_PGTABLE_WALK_SKIP_BBM_TLBI); } -#define KVM_PHYS_INVALID (-1ULL) - -static bool kvm_phys_is_valid(u64 phys) +static bool kvm_pgtable_walk_skip_cmo(const struct kvm_pgtable_visit_ctx *ctx) { - return phys < BIT(id_aa64mmfr0_parange_to_phys_shift(ID_AA64MMFR0_PARANGE_MAX)); -} - -static bool kvm_level_supports_block_mapping(u32 level) -{ - /* - * Reject invalid block mappings and don't bother with 4TB mappings for - * 52-bit PAs. - */ - return !(level == 0 || (PAGE_SIZE != SZ_4K && level == 1)); + return unlikely(ctx->flags & KVM_PGTABLE_WALK_SKIP_CMO); } -static bool kvm_block_mapping_supported(u64 addr, u64 end, u64 phys, u32 level) +static bool kvm_block_mapping_supported(const struct kvm_pgtable_visit_ctx *ctx, u64 phys) { - u64 granule = kvm_granule_size(level); + u64 granule = kvm_granule_size(ctx->level); - if (!kvm_level_supports_block_mapping(level)) + if (!kvm_level_supports_block_mapping(ctx->level)) return false; - if (granule > (end - addr)) + if (granule > (ctx->end - ctx->addr)) return false; - if (kvm_phys_is_valid(phys) && !IS_ALIGNED(phys, granule)) + if (!IS_ALIGNED(phys, granule)) return false; - return IS_ALIGNED(addr, granule); + return IS_ALIGNED(ctx->addr, granule); } -static u32 kvm_pgtable_idx(struct kvm_pgtable_walk_data *data, u32 level) +static u32 kvm_pgtable_idx(struct kvm_pgtable_walk_data *data, s8 level) { u64 shift = kvm_granule_shift(level); u64 mask = BIT(PAGE_SHIFT - 3) - 1; @@ -112,7 +53,7 @@ static u32 kvm_pgtable_idx(struct kvm_pgtable_walk_data *data, u32 level) return (data->addr >> shift) & mask; } -static u32 __kvm_pgd_page_idx(struct kvm_pgtable *pgt, u64 addr) +static u32 kvm_pgd_page_idx(struct kvm_pgtable *pgt, u64 addr) { u64 shift = kvm_granule_shift(pgt->start_level - 1); /* May underflow */ u64 mask = BIT(pgt->ia_bits) - 1; @@ -120,29 +61,19 @@ static u32 __kvm_pgd_page_idx(struct kvm_pgtable *pgt, u64 addr) return (addr & mask) >> shift; } -static u32 kvm_pgd_page_idx(struct kvm_pgtable_walk_data *data) -{ - return __kvm_pgd_page_idx(data->pgt, data->addr); -} - -static u32 kvm_pgd_pages(u32 ia_bits, u32 start_level) +static u32 kvm_pgd_pages(u32 ia_bits, s8 start_level) { struct kvm_pgtable pgt = { .ia_bits = ia_bits, .start_level = start_level, }; - return __kvm_pgd_page_idx(&pgt, -1ULL) + 1; + return kvm_pgd_page_idx(&pgt, -1ULL) + 1; } -static bool kvm_pte_valid(kvm_pte_t pte) +static bool kvm_pte_table(kvm_pte_t pte, s8 level) { - return pte & KVM_PTE_VALID; -} - -static bool kvm_pte_table(kvm_pte_t pte, u32 level) -{ - if (level == KVM_PGTABLE_MAX_LEVELS - 1) + if (level == KVM_PGTABLE_LAST_LEVEL) return false; if (!kvm_pte_valid(pte)) @@ -151,26 +82,6 @@ static bool kvm_pte_table(kvm_pte_t pte, u32 level) return FIELD_GET(KVM_PTE_TYPE, pte) == KVM_PTE_TYPE_TABLE; } -static u64 kvm_pte_to_phys(kvm_pte_t pte) -{ - u64 pa = pte & KVM_PTE_ADDR_MASK; - - if (PAGE_SHIFT == 16) - pa |= FIELD_GET(KVM_PTE_ADDR_51_48, pte) << 48; - - return pa; -} - -static kvm_pte_t kvm_phys_to_pte(u64 pa) -{ - kvm_pte_t pte = pa & KVM_PTE_ADDR_MASK; - - if (PAGE_SHIFT == 16) - pte |= FIELD_PREP(KVM_PTE_ADDR_51_48, pa >> 48); - - return pte; -} - static kvm_pte_t *kvm_pte_follow(kvm_pte_t pte, struct kvm_pgtable_mm_ops *mm_ops) { return mm_ops->phys_to_virt(kvm_pte_to_phys(pte)); @@ -181,23 +92,20 @@ static void kvm_clear_pte(kvm_pte_t *ptep) WRITE_ONCE(*ptep, 0); } -static void kvm_set_table_pte(kvm_pte_t *ptep, kvm_pte_t *childp, - struct kvm_pgtable_mm_ops *mm_ops) +static kvm_pte_t kvm_init_table_pte(kvm_pte_t *childp, struct kvm_pgtable_mm_ops *mm_ops) { - kvm_pte_t old = *ptep, pte = kvm_phys_to_pte(mm_ops->virt_to_phys(childp)); + kvm_pte_t pte = kvm_phys_to_pte(mm_ops->virt_to_phys(childp)); pte |= FIELD_PREP(KVM_PTE_TYPE, KVM_PTE_TYPE_TABLE); pte |= KVM_PTE_VALID; - - WARN_ON(kvm_pte_valid(old)); - smp_store_release(ptep, pte); + return pte; } -static kvm_pte_t kvm_init_valid_leaf_pte(u64 pa, kvm_pte_t attr, u32 level) +static kvm_pte_t kvm_init_valid_leaf_pte(u64 pa, kvm_pte_t attr, s8 level) { kvm_pte_t pte = kvm_phys_to_pte(pa); - u64 type = (level == KVM_PGTABLE_MAX_LEVELS - 1) ? KVM_PTE_TYPE_PAGE : - KVM_PTE_TYPE_BLOCK; + u64 type = (level == KVM_PGTABLE_LAST_LEVEL) ? KVM_PTE_TYPE_PAGE : + KVM_PTE_TYPE_BLOCK; pte |= attr & (KVM_PTE_LEAF_ATTR_LO | KVM_PTE_LEAF_ATTR_HI); pte |= FIELD_PREP(KVM_PTE_TYPE, type); @@ -211,39 +119,82 @@ static kvm_pte_t kvm_init_invalid_leaf_owner(u8 owner_id) return FIELD_PREP(KVM_INVALID_PTE_OWNER_MASK, owner_id); } -static int kvm_pgtable_visitor_cb(struct kvm_pgtable_walk_data *data, u64 addr, - u32 level, kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag) +static int kvm_pgtable_visitor_cb(struct kvm_pgtable_walk_data *data, + const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { struct kvm_pgtable_walker *walker = data->walker; - return walker->cb(addr, data->end, level, ptep, flag, walker->arg); + + /* Ensure the appropriate lock is held (e.g. RCU lock for stage-2 MMU) */ + WARN_ON_ONCE(kvm_pgtable_walk_shared(ctx) && !kvm_pgtable_walk_lock_held()); + return walker->cb(ctx, visit); +} + +static bool kvm_pgtable_walk_continue(const struct kvm_pgtable_walker *walker, + int r) +{ + /* + * Visitor callbacks return EAGAIN when the conditions that led to a + * fault are no longer reflected in the page tables due to a race to + * update a PTE. In the context of a fault handler this is interpreted + * as a signal to retry guest execution. + * + * Ignore the return code altogether for walkers outside a fault handler + * (e.g. write protecting a range of memory) and chug along with the + * page table walk. + */ + if (r == -EAGAIN) + return !(walker->flags & KVM_PGTABLE_WALK_HANDLE_FAULT); + + return !r; } static int __kvm_pgtable_walk(struct kvm_pgtable_walk_data *data, - kvm_pte_t *pgtable, u32 level); + struct kvm_pgtable_mm_ops *mm_ops, kvm_pteref_t pgtable, s8 level); static inline int __kvm_pgtable_visit(struct kvm_pgtable_walk_data *data, - kvm_pte_t *ptep, u32 level) + struct kvm_pgtable_mm_ops *mm_ops, + kvm_pteref_t pteref, s8 level) { - int ret = 0; - u64 addr = data->addr; - kvm_pte_t *childp, pte = *ptep; - bool table = kvm_pte_table(pte, level); enum kvm_pgtable_walk_flags flags = data->walker->flags; + kvm_pte_t *ptep = kvm_dereference_pteref(data->walker, pteref); + struct kvm_pgtable_visit_ctx ctx = { + .ptep = ptep, + .old = READ_ONCE(*ptep), + .arg = data->walker->arg, + .mm_ops = mm_ops, + .start = data->start, + .addr = data->addr, + .end = data->end, + .level = level, + .flags = flags, + }; + int ret = 0; + bool reload = false; + kvm_pteref_t childp; + bool table = kvm_pte_table(ctx.old, level); - if (table && (flags & KVM_PGTABLE_WALK_TABLE_PRE)) { - ret = kvm_pgtable_visitor_cb(data, addr, level, ptep, - KVM_PGTABLE_WALK_TABLE_PRE); + if (table && (ctx.flags & KVM_PGTABLE_WALK_TABLE_PRE)) { + ret = kvm_pgtable_visitor_cb(data, &ctx, KVM_PGTABLE_WALK_TABLE_PRE); + reload = true; } - if (!table && (flags & KVM_PGTABLE_WALK_LEAF)) { - ret = kvm_pgtable_visitor_cb(data, addr, level, ptep, - KVM_PGTABLE_WALK_LEAF); - pte = *ptep; - table = kvm_pte_table(pte, level); + if (!table && (ctx.flags & KVM_PGTABLE_WALK_LEAF)) { + ret = kvm_pgtable_visitor_cb(data, &ctx, KVM_PGTABLE_WALK_LEAF); + reload = true; } - if (ret) + /* + * Reload the page table after invoking the walker callback for leaf + * entries or after pre-order traversal, to allow the walker to descend + * into a newly installed or replaced table. + */ + if (reload) { + ctx.old = READ_ONCE(*ptep); + table = kvm_pte_table(ctx.old, level); + } + + if (!kvm_pgtable_walk_continue(data->walker, ret)) goto out; if (!table) { @@ -252,36 +203,38 @@ static inline int __kvm_pgtable_visit(struct kvm_pgtable_walk_data *data, goto out; } - childp = kvm_pte_follow(pte, data->pgt->mm_ops); - ret = __kvm_pgtable_walk(data, childp, level + 1); - if (ret) + childp = (kvm_pteref_t)kvm_pte_follow(ctx.old, mm_ops); + ret = __kvm_pgtable_walk(data, mm_ops, childp, level + 1); + if (!kvm_pgtable_walk_continue(data->walker, ret)) goto out; - if (flags & KVM_PGTABLE_WALK_TABLE_POST) { - ret = kvm_pgtable_visitor_cb(data, addr, level, ptep, - KVM_PGTABLE_WALK_TABLE_POST); - } + if (ctx.flags & KVM_PGTABLE_WALK_TABLE_POST) + ret = kvm_pgtable_visitor_cb(data, &ctx, KVM_PGTABLE_WALK_TABLE_POST); out: + if (kvm_pgtable_walk_continue(data->walker, ret)) + return 0; + return ret; } static int __kvm_pgtable_walk(struct kvm_pgtable_walk_data *data, - kvm_pte_t *pgtable, u32 level) + struct kvm_pgtable_mm_ops *mm_ops, kvm_pteref_t pgtable, s8 level) { u32 idx; int ret = 0; - if (WARN_ON_ONCE(level >= KVM_PGTABLE_MAX_LEVELS)) + if (WARN_ON_ONCE(level < KVM_PGTABLE_FIRST_LEVEL || + level > KVM_PGTABLE_LAST_LEVEL)) return -EINVAL; for (idx = kvm_pgtable_idx(data, level); idx < PTRS_PER_PTE; ++idx) { - kvm_pte_t *ptep = &pgtable[idx]; + kvm_pteref_t pteref = &pgtable[idx]; if (data->addr >= data->end) break; - ret = __kvm_pgtable_visit(data, ptep, level); + ret = __kvm_pgtable_visit(data, mm_ops, pteref, level); if (ret) break; } @@ -289,11 +242,10 @@ static int __kvm_pgtable_walk(struct kvm_pgtable_walk_data *data, return ret; } -static int _kvm_pgtable_walk(struct kvm_pgtable_walk_data *data) +static int _kvm_pgtable_walk(struct kvm_pgtable *pgt, struct kvm_pgtable_walk_data *data) { u32 idx; int ret = 0; - struct kvm_pgtable *pgt = data->pgt; u64 limit = BIT(pgt->ia_bits); if (data->addr > limit || data->end > limit) @@ -302,10 +254,10 @@ static int _kvm_pgtable_walk(struct kvm_pgtable_walk_data *data) if (!pgt->pgd) return -EINVAL; - for (idx = kvm_pgd_page_idx(data); data->addr < data->end; ++idx) { - kvm_pte_t *ptep = &pgt->pgd[idx * PTRS_PER_PTE]; + for (idx = kvm_pgd_page_idx(pgt, data->addr); data->addr < data->end; ++idx) { + kvm_pteref_t pteref = &pgt->pgd[idx * PTRS_PER_PTE]; - ret = __kvm_pgtable_walk(data, ptep, pgt->start_level); + ret = __kvm_pgtable_walk(data, pgt->mm_ops, pteref, pgt->start_level); if (ret) break; } @@ -317,19 +269,65 @@ int kvm_pgtable_walk(struct kvm_pgtable *pgt, u64 addr, u64 size, struct kvm_pgtable_walker *walker) { struct kvm_pgtable_walk_data walk_data = { - .pgt = pgt, + .start = ALIGN_DOWN(addr, PAGE_SIZE), .addr = ALIGN_DOWN(addr, PAGE_SIZE), .end = PAGE_ALIGN(walk_data.addr + size), .walker = walker, }; + int r; + + r = kvm_pgtable_walk_begin(walker); + if (r) + return r; + + r = _kvm_pgtable_walk(pgt, &walk_data); + kvm_pgtable_walk_end(walker); + + return r; +} + +struct leaf_walk_data { + kvm_pte_t pte; + s8 level; +}; + +static int leaf_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) +{ + struct leaf_walk_data *data = ctx->arg; + + data->pte = ctx->old; + data->level = ctx->level; - return _kvm_pgtable_walk(&walk_data); + return 0; +} + +int kvm_pgtable_get_leaf(struct kvm_pgtable *pgt, u64 addr, + kvm_pte_t *ptep, s8 *level) +{ + struct leaf_walk_data data; + struct kvm_pgtable_walker walker = { + .cb = leaf_walker, + .flags = KVM_PGTABLE_WALK_LEAF, + .arg = &data, + }; + int ret; + + ret = kvm_pgtable_walk(pgt, ALIGN_DOWN(addr, PAGE_SIZE), + PAGE_SIZE, &walker); + if (!ret) { + if (ptep) + *ptep = data.pte; + if (level) + *level = data.level; + } + + return ret; } struct hyp_map_data { - u64 phys; + const u64 phys; kvm_pte_t attr; - struct kvm_pgtable_mm_ops *mm_ops; }; static int hyp_set_prot_attr(enum kvm_pgtable_prot prot, kvm_pte_t *ptep) @@ -350,54 +348,85 @@ static int hyp_set_prot_attr(enum kvm_pgtable_prot prot, kvm_pte_t *ptep) if (device) return -EINVAL; + + if (system_supports_bti_kernel()) + attr |= KVM_PTE_LEAF_ATTR_HI_S1_GP; } else { attr |= KVM_PTE_LEAF_ATTR_HI_S1_XN; } attr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S1_AP, ap); - attr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S1_SH, sh); + if (!kvm_lpa2_is_enabled()) + attr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S1_SH, sh); attr |= KVM_PTE_LEAF_ATTR_LO_S1_AF; + attr |= prot & KVM_PTE_LEAF_ATTR_HI_SW; *ptep = attr; return 0; } -static bool hyp_map_walker_try_leaf(u64 addr, u64 end, u32 level, - kvm_pte_t *ptep, struct hyp_map_data *data) +enum kvm_pgtable_prot kvm_pgtable_hyp_pte_prot(kvm_pte_t pte) +{ + enum kvm_pgtable_prot prot = pte & KVM_PTE_LEAF_ATTR_HI_SW; + u32 ap; + + if (!kvm_pte_valid(pte)) + return prot; + + if (!(pte & KVM_PTE_LEAF_ATTR_HI_S1_XN)) + prot |= KVM_PGTABLE_PROT_X; + + ap = FIELD_GET(KVM_PTE_LEAF_ATTR_LO_S1_AP, pte); + if (ap == KVM_PTE_LEAF_ATTR_LO_S1_AP_RO) + prot |= KVM_PGTABLE_PROT_R; + else if (ap == KVM_PTE_LEAF_ATTR_LO_S1_AP_RW) + prot |= KVM_PGTABLE_PROT_RW; + + return prot; +} + +static bool hyp_map_walker_try_leaf(const struct kvm_pgtable_visit_ctx *ctx, + struct hyp_map_data *data) { - kvm_pte_t new, old = *ptep; - u64 granule = kvm_granule_size(level), phys = data->phys; + u64 phys = data->phys + (ctx->addr - ctx->start); + kvm_pte_t new; - if (!kvm_block_mapping_supported(addr, end, phys, level)) + if (!kvm_block_mapping_supported(ctx, phys)) return false; - /* Tolerate KVM recreating the exact same mapping */ - new = kvm_init_valid_leaf_pte(phys, data->attr, level); - if (old != new && !WARN_ON(kvm_pte_valid(old))) - smp_store_release(ptep, new); + new = kvm_init_valid_leaf_pte(phys, data->attr, ctx->level); + if (ctx->old == new) + return true; + if (!kvm_pte_valid(ctx->old)) + ctx->mm_ops->get_page(ctx->ptep); + else if (WARN_ON((ctx->old ^ new) & ~KVM_PTE_LEAF_ATTR_HI_SW)) + return false; - data->phys += granule; + smp_store_release(ctx->ptep, new); return true; } -static int hyp_map_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, void * const arg) +static int hyp_map_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { - kvm_pte_t *childp; - struct hyp_map_data *data = arg; - struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops; + kvm_pte_t *childp, new; + struct hyp_map_data *data = ctx->arg; + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; - if (hyp_map_walker_try_leaf(addr, end, level, ptep, arg)) + if (hyp_map_walker_try_leaf(ctx, data)) return 0; - if (WARN_ON(level == KVM_PGTABLE_MAX_LEVELS - 1)) + if (WARN_ON(ctx->level == KVM_PGTABLE_LAST_LEVEL)) return -EINVAL; childp = (kvm_pte_t *)mm_ops->zalloc_page(NULL); if (!childp) return -ENOMEM; - kvm_set_table_pte(ptep, childp, mm_ops); + new = kvm_init_table_pte(childp, mm_ops); + mm_ops->get_page(ctx->ptep); + smp_store_release(ctx->ptep, new); + return 0; } @@ -407,7 +436,6 @@ int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys, int ret; struct hyp_map_data map_data = { .phys = ALIGN_DOWN(phys, PAGE_SIZE), - .mm_ops = pgt->mm_ops, }; struct kvm_pgtable_walker walker = { .cb = hyp_map_walker, @@ -425,28 +453,98 @@ int kvm_pgtable_hyp_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys, return ret; } +static int hyp_unmap_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) +{ + kvm_pte_t *childp = NULL; + u64 granule = kvm_granule_size(ctx->level); + u64 *unmapped = ctx->arg; + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; + + if (!kvm_pte_valid(ctx->old)) + return -EINVAL; + + if (kvm_pte_table(ctx->old, ctx->level)) { + childp = kvm_pte_follow(ctx->old, mm_ops); + + if (mm_ops->page_count(childp) != 1) + return 0; + + kvm_clear_pte(ctx->ptep); + dsb(ishst); + __tlbi_level(vae2is, __TLBI_VADDR(ctx->addr, 0), TLBI_TTL_UNKNOWN); + } else { + if (ctx->end - ctx->addr < granule) + return -EINVAL; + + kvm_clear_pte(ctx->ptep); + dsb(ishst); + __tlbi_level(vale2is, __TLBI_VADDR(ctx->addr, 0), ctx->level); + *unmapped += granule; + } + + dsb(ish); + isb(); + mm_ops->put_page(ctx->ptep); + + if (childp) + mm_ops->put_page(childp); + + return 0; +} + +u64 kvm_pgtable_hyp_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size) +{ + u64 unmapped = 0; + struct kvm_pgtable_walker walker = { + .cb = hyp_unmap_walker, + .arg = &unmapped, + .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST, + }; + + if (!pgt->mm_ops->page_count) + return 0; + + kvm_pgtable_walk(pgt, addr, size, &walker); + return unmapped; +} + int kvm_pgtable_hyp_init(struct kvm_pgtable *pgt, u32 va_bits, struct kvm_pgtable_mm_ops *mm_ops) { - u64 levels = ARM64_HW_PGTABLE_LEVELS(va_bits); + s8 start_level = KVM_PGTABLE_LAST_LEVEL + 1 - + ARM64_HW_PGTABLE_LEVELS(va_bits); + + if (start_level < KVM_PGTABLE_FIRST_LEVEL || + start_level > KVM_PGTABLE_LAST_LEVEL) + return -EINVAL; - pgt->pgd = (kvm_pte_t *)mm_ops->zalloc_page(NULL); + pgt->pgd = (kvm_pteref_t)mm_ops->zalloc_page(NULL); if (!pgt->pgd) return -ENOMEM; pgt->ia_bits = va_bits; - pgt->start_level = KVM_PGTABLE_MAX_LEVELS - levels; + pgt->start_level = start_level; pgt->mm_ops = mm_ops; pgt->mmu = NULL; + pgt->force_pte_cb = NULL; + return 0; } -static int hyp_free_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, void * const arg) +static int hyp_free_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { - struct kvm_pgtable_mm_ops *mm_ops = arg; + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; + + if (!kvm_pte_valid(ctx->old)) + return 0; + + mm_ops->put_page(ctx->ptep); + + if (kvm_pte_table(ctx->old, ctx->level)) + mm_ops->put_page(kvm_pte_follow(ctx->old, mm_ops)); - mm_ops->put_page((void *)kvm_pte_follow(*ptep, mm_ops)); return 0; } @@ -454,17 +552,16 @@ void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt) { struct kvm_pgtable_walker walker = { .cb = hyp_free_walker, - .flags = KVM_PGTABLE_WALK_TABLE_POST, - .arg = pgt->mm_ops, + .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST, }; WARN_ON(kvm_pgtable_walk(pgt, 0, BIT(pgt->ia_bits), &walker)); - pgt->mm_ops->put_page(pgt->pgd); + pgt->mm_ops->put_page(kvm_dereference_pteref(&walker, pgt->pgd)); pgt->pgd = NULL; } struct stage2_map_data { - u64 phys; + const u64 phys; kvm_pte_t attr; u8 owner_id; @@ -474,13 +571,17 @@ struct stage2_map_data { struct kvm_s2_mmu *mmu; void *memcache; - struct kvm_pgtable_mm_ops *mm_ops; + /* Force mappings to page granularity */ + bool force_pte; + + /* Walk should update owner_id only */ + bool annotation; }; u64 kvm_get_vtcr(u64 mmfr0, u64 mmfr1, u32 phys_shift) { u64 vtcr = VTCR_EL2_FLAGS; - u8 lvls; + s8 lvls; vtcr |= kvm_get_parange(mmfr0) << VTCR_EL2_PS_SHIFT; vtcr |= VTCR_EL2_T0SZ(phys_shift); @@ -491,14 +592,36 @@ u64 kvm_get_vtcr(u64 mmfr0, u64 mmfr1, u32 phys_shift) lvls = stage2_pgtable_levels(phys_shift); if (lvls < 2) lvls = 2; + + /* + * When LPA2 is enabled, the HW supports an extra level of translation + * (for 5 in total) when using 4K pages. It also introduces VTCR_EL2.SL2 + * to as an addition to SL0 to enable encoding this extra start level. + * However, since we always use concatenated pages for the first level + * lookup, we will never need this extra level and therefore do not need + * to touch SL2. + */ vtcr |= VTCR_EL2_LVLS_TO_SL0(lvls); +#ifdef CONFIG_ARM64_HW_AFDBM /* * Enable the Hardware Access Flag management, unconditionally - * on all CPUs. The features is RES0 on CPUs without the support - * and must be ignored by the CPUs. + * on all CPUs. In systems that have asymmetric support for the feature + * this allows KVM to leverage hardware support on the subset of cores + * that implement the feature. + * + * The architecture requires VTCR_EL2.HA to be RES0 (thus ignored by + * hardware) on implementations that do not advertise support for the + * feature. As such, setting HA unconditionally is safe, unless you + * happen to be running on a design that has unadvertised support for + * HAFDBS. Here be dragons. */ - vtcr |= VTCR_EL2_HA; + if (!cpus_have_final_cap(ARM64_WORKAROUND_AMPERE_AC03_CPU_38)) + vtcr |= VTCR_EL2_HA; +#endif /* CONFIG_ARM64_HW_AFDBM */ + + if (kvm_lpa2_is_enabled()) + vtcr |= VTCR_EL2_DS; /* Set the vmid bits */ vtcr |= (get_vmid_bits(mmfr1) == 16) ? @@ -510,26 +633,87 @@ u64 kvm_get_vtcr(u64 mmfr0, u64 mmfr1, u32 phys_shift) static bool stage2_has_fwb(struct kvm_pgtable *pgt) { - if (!cpus_have_const_cap(ARM64_HAS_STAGE2_FWB)) + if (!cpus_have_final_cap(ARM64_HAS_STAGE2_FWB)) return false; return !(pgt->flags & KVM_PGTABLE_S2_NOFWB); } +void kvm_tlb_flush_vmid_range(struct kvm_s2_mmu *mmu, + phys_addr_t addr, size_t size) +{ + unsigned long pages, inval_pages; + + if (!system_supports_tlb_range()) { + kvm_call_hyp(__kvm_tlb_flush_vmid, mmu); + return; + } + + pages = size >> PAGE_SHIFT; + while (pages > 0) { + inval_pages = min(pages, MAX_TLBI_RANGE_PAGES); + kvm_call_hyp(__kvm_tlb_flush_vmid_range, mmu, addr, inval_pages); + + addr += inval_pages << PAGE_SHIFT; + pages -= inval_pages; + } +} + #define KVM_S2_MEMATTR(pgt, attr) PAGE_S2_MEMATTR(attr, stage2_has_fwb(pgt)) +static int stage2_set_xn_attr(enum kvm_pgtable_prot prot, kvm_pte_t *attr) +{ + bool px, ux; + u8 xn; + + px = prot & KVM_PGTABLE_PROT_PX; + ux = prot & KVM_PGTABLE_PROT_UX; + + if (!cpus_have_final_cap(ARM64_HAS_XNX) && px != ux) + return -EINVAL; + + if (px && ux) + xn = 0b00; + else if (!px && ux) + xn = 0b01; + else if (!px && !ux) + xn = 0b10; + else + xn = 0b11; + + *attr &= ~KVM_PTE_LEAF_ATTR_HI_S2_XN; + *attr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_HI_S2_XN, xn); + return 0; +} + static int stage2_set_prot_attr(struct kvm_pgtable *pgt, enum kvm_pgtable_prot prot, kvm_pte_t *ptep) { - bool device = prot & KVM_PGTABLE_PROT_DEVICE; - kvm_pte_t attr = device ? KVM_S2_MEMATTR(pgt, DEVICE_nGnRE) : - KVM_S2_MEMATTR(pgt, NORMAL); + kvm_pte_t attr; u32 sh = KVM_PTE_LEAF_ATTR_LO_S2_SH_IS; + int r; - if (!(prot & KVM_PGTABLE_PROT_X)) - attr |= KVM_PTE_LEAF_ATTR_HI_S2_XN; - else if (device) + switch (prot & (KVM_PGTABLE_PROT_DEVICE | + KVM_PGTABLE_PROT_NORMAL_NC)) { + case KVM_PGTABLE_PROT_DEVICE | KVM_PGTABLE_PROT_NORMAL_NC: return -EINVAL; + case KVM_PGTABLE_PROT_DEVICE: + if (prot & KVM_PGTABLE_PROT_X) + return -EINVAL; + attr = KVM_S2_MEMATTR(pgt, DEVICE_nGnRE); + break; + case KVM_PGTABLE_PROT_NORMAL_NC: + if (prot & KVM_PGTABLE_PROT_X) + return -EINVAL; + attr = KVM_S2_MEMATTR(pgt, NORMAL_NC); + break; + default: + attr = KVM_S2_MEMATTR(pgt, NORMAL); + } + + r = stage2_set_xn_attr(prot, &attr); + if (r) + return r; if (prot & KVM_PGTABLE_PROT_R) attr |= KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R; @@ -537,13 +721,45 @@ static int stage2_set_prot_attr(struct kvm_pgtable *pgt, enum kvm_pgtable_prot p if (prot & KVM_PGTABLE_PROT_W) attr |= KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W; - attr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S2_SH, sh); + if (!kvm_lpa2_is_enabled()) + attr |= FIELD_PREP(KVM_PTE_LEAF_ATTR_LO_S2_SH, sh); + attr |= KVM_PTE_LEAF_ATTR_LO_S2_AF; + attr |= prot & KVM_PTE_LEAF_ATTR_HI_SW; *ptep = attr; return 0; } +enum kvm_pgtable_prot kvm_pgtable_stage2_pte_prot(kvm_pte_t pte) +{ + enum kvm_pgtable_prot prot = pte & KVM_PTE_LEAF_ATTR_HI_SW; + + if (!kvm_pte_valid(pte)) + return prot; + + if (pte & KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R) + prot |= KVM_PGTABLE_PROT_R; + if (pte & KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W) + prot |= KVM_PGTABLE_PROT_W; + + switch (FIELD_GET(KVM_PTE_LEAF_ATTR_HI_S2_XN, pte)) { + case 0b00: + prot |= KVM_PGTABLE_PROT_PX | KVM_PGTABLE_PROT_UX; + break; + case 0b01: + prot |= KVM_PGTABLE_PROT_UX; + break; + case 0b11: + prot |= KVM_PGTABLE_PROT_PX; + break; + default: + break; + } + + return prot; +} + static bool stage2_pte_needs_update(kvm_pte_t old, kvm_pte_t new) { if (!kvm_pte_valid(old) || !kvm_pte_valid(new)) @@ -562,120 +778,248 @@ static bool stage2_pte_is_counted(kvm_pte_t pte) return !!pte; } -static void stage2_put_pte(kvm_pte_t *ptep, struct kvm_s2_mmu *mmu, u64 addr, - u32 level, struct kvm_pgtable_mm_ops *mm_ops) +static bool stage2_pte_is_locked(kvm_pte_t pte) +{ + return !kvm_pte_valid(pte) && (pte & KVM_INVALID_PTE_LOCKED); +} + +static bool stage2_try_set_pte(const struct kvm_pgtable_visit_ctx *ctx, kvm_pte_t new) +{ + if (!kvm_pgtable_walk_shared(ctx)) { + WRITE_ONCE(*ctx->ptep, new); + return true; + } + + return cmpxchg(ctx->ptep, ctx->old, new) == ctx->old; +} + +/** + * stage2_try_break_pte() - Invalidates a pte according to the + * 'break-before-make' requirements of the + * architecture. + * + * @ctx: context of the visited pte. + * @mmu: stage-2 mmu + * + * Returns: true if the pte was successfully broken. + * + * If the removed pte was valid, performs the necessary serialization and TLB + * invalidation for the old value. For counted ptes, drops the reference count + * on the containing table page. + */ +static bool stage2_try_break_pte(const struct kvm_pgtable_visit_ctx *ctx, + struct kvm_s2_mmu *mmu) +{ + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; + + if (stage2_pte_is_locked(ctx->old)) { + /* + * Should never occur if this walker has exclusive access to the + * page tables. + */ + WARN_ON(!kvm_pgtable_walk_shared(ctx)); + return false; + } + + if (!stage2_try_set_pte(ctx, KVM_INVALID_PTE_LOCKED)) + return false; + + if (!kvm_pgtable_walk_skip_bbm_tlbi(ctx)) { + /* + * Perform the appropriate TLB invalidation based on the + * evicted pte value (if any). + */ + if (kvm_pte_table(ctx->old, ctx->level)) { + u64 size = kvm_granule_size(ctx->level); + u64 addr = ALIGN_DOWN(ctx->addr, size); + + kvm_tlb_flush_vmid_range(mmu, addr, size); + } else if (kvm_pte_valid(ctx->old)) { + kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu, + ctx->addr, ctx->level); + } + } + + if (stage2_pte_is_counted(ctx->old)) + mm_ops->put_page(ctx->ptep); + + return true; +} + +static void stage2_make_pte(const struct kvm_pgtable_visit_ctx *ctx, kvm_pte_t new) +{ + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; + + WARN_ON(!stage2_pte_is_locked(*ctx->ptep)); + + if (stage2_pte_is_counted(new)) + mm_ops->get_page(ctx->ptep); + + smp_store_release(ctx->ptep, new); +} + +static bool stage2_unmap_defer_tlb_flush(struct kvm_pgtable *pgt) { /* - * Clear the existing PTE, and perform break-before-make with - * TLB maintenance if it was valid. + * If FEAT_TLBIRANGE is implemented, defer the individual + * TLB invalidations until the entire walk is finished, and + * then use the range-based TLBI instructions to do the + * invalidations. Condition deferred TLB invalidation on the + * system supporting FWB as the optimization is entirely + * pointless when the unmap walker needs to perform CMOs. */ - if (kvm_pte_valid(*ptep)) { - kvm_clear_pte(ptep); - kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu, addr, level); + return system_supports_tlb_range() && stage2_has_fwb(pgt); +} + +static void stage2_unmap_put_pte(const struct kvm_pgtable_visit_ctx *ctx, + struct kvm_s2_mmu *mmu, + struct kvm_pgtable_mm_ops *mm_ops) +{ + struct kvm_pgtable *pgt = ctx->arg; + + /* + * Clear the existing PTE, and perform break-before-make if it was + * valid. Depending on the system support, defer the TLB maintenance + * for the same until the entire unmap walk is completed. + */ + if (kvm_pte_valid(ctx->old)) { + kvm_clear_pte(ctx->ptep); + + if (kvm_pte_table(ctx->old, ctx->level)) { + kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu, ctx->addr, + TLBI_TTL_UNKNOWN); + } else if (!stage2_unmap_defer_tlb_flush(pgt)) { + kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu, ctx->addr, + ctx->level); + } } - mm_ops->put_page(ptep); + mm_ops->put_page(ctx->ptep); } static bool stage2_pte_cacheable(struct kvm_pgtable *pgt, kvm_pte_t pte) { u64 memattr = pte & KVM_PTE_LEAF_ATTR_LO_S2_MEMATTR; - return memattr == KVM_S2_MEMATTR(pgt, NORMAL); + return kvm_pte_valid(pte) && memattr == KVM_S2_MEMATTR(pgt, NORMAL); } static bool stage2_pte_executable(kvm_pte_t pte) { - return !(pte & KVM_PTE_LEAF_ATTR_HI_S2_XN); + return kvm_pte_valid(pte) && !(pte & KVM_PTE_LEAF_ATTR_HI_S2_XN); +} + +static u64 stage2_map_walker_phys_addr(const struct kvm_pgtable_visit_ctx *ctx, + const struct stage2_map_data *data) +{ + u64 phys = data->phys; + + /* Work out the correct PA based on how far the walk has gotten */ + return phys + (ctx->addr - ctx->start); +} + +static bool stage2_leaf_mapping_allowed(const struct kvm_pgtable_visit_ctx *ctx, + struct stage2_map_data *data) +{ + u64 phys = stage2_map_walker_phys_addr(ctx, data); + + if (data->force_pte && ctx->level < KVM_PGTABLE_LAST_LEVEL) + return false; + + if (data->annotation) + return true; + + return kvm_block_mapping_supported(ctx, phys); } -static int stage2_map_walker_try_leaf(u64 addr, u64 end, u32 level, - kvm_pte_t *ptep, +static int stage2_map_walker_try_leaf(const struct kvm_pgtable_visit_ctx *ctx, struct stage2_map_data *data) { - kvm_pte_t new, old = *ptep; - u64 granule = kvm_granule_size(level), phys = data->phys; + kvm_pte_t new; + u64 phys = stage2_map_walker_phys_addr(ctx, data); + u64 granule = kvm_granule_size(ctx->level); struct kvm_pgtable *pgt = data->mmu->pgt; - struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops; + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; - if (!kvm_block_mapping_supported(addr, end, phys, level)) + if (!stage2_leaf_mapping_allowed(ctx, data)) return -E2BIG; - if (kvm_phys_is_valid(phys)) - new = kvm_init_valid_leaf_pte(phys, data->attr, level); + if (!data->annotation) + new = kvm_init_valid_leaf_pte(phys, data->attr, ctx->level); else new = kvm_init_invalid_leaf_owner(data->owner_id); - if (stage2_pte_is_counted(old)) { - /* - * Skip updating the PTE if we are trying to recreate the exact - * same mapping or only change the access permissions. Instead, - * the vCPU will exit one more time from guest if still needed - * and then go through the path of relaxing permissions. - */ - if (!stage2_pte_needs_update(old, new)) - return -EAGAIN; - - stage2_put_pte(ptep, data->mmu, addr, level, mm_ops); + /* + * Skip updating the PTE if we are trying to recreate the exact + * same mapping or only change the access permissions. Instead, + * the vCPU will exit one more time from guest if still needed + * and then go through the path of relaxing permissions. + */ + if (!stage2_pte_needs_update(ctx->old, new)) + return -EAGAIN; + + /* If we're only changing software bits, then store them and go! */ + if (!kvm_pgtable_walk_shared(ctx) && + !((ctx->old ^ new) & ~KVM_PTE_LEAF_ATTR_HI_SW)) { + bool old_is_counted = stage2_pte_is_counted(ctx->old); + + if (old_is_counted != stage2_pte_is_counted(new)) { + if (old_is_counted) + mm_ops->put_page(ctx->ptep); + else + mm_ops->get_page(ctx->ptep); + } + WARN_ON_ONCE(!stage2_try_set_pte(ctx, new)); + return 0; } + if (!stage2_try_break_pte(ctx, data->mmu)) + return -EAGAIN; + /* Perform CMOs before installation of the guest stage-2 PTE */ - if (mm_ops->dcache_clean_inval_poc && stage2_pte_cacheable(pgt, new)) + if (!kvm_pgtable_walk_skip_cmo(ctx) && mm_ops->dcache_clean_inval_poc && + stage2_pte_cacheable(pgt, new)) mm_ops->dcache_clean_inval_poc(kvm_pte_follow(new, mm_ops), - granule); + granule); - if (mm_ops->icache_inval_pou && stage2_pte_executable(new)) + if (!kvm_pgtable_walk_skip_cmo(ctx) && mm_ops->icache_inval_pou && + stage2_pte_executable(new)) mm_ops->icache_inval_pou(kvm_pte_follow(new, mm_ops), granule); - smp_store_release(ptep, new); - if (stage2_pte_is_counted(new)) - mm_ops->get_page(ptep); - if (kvm_phys_is_valid(phys)) - data->phys += granule; + stage2_make_pte(ctx, new); + return 0; } -static int stage2_map_walk_table_pre(u64 addr, u64 end, u32 level, - kvm_pte_t *ptep, +static int stage2_map_walk_table_pre(const struct kvm_pgtable_visit_ctx *ctx, struct stage2_map_data *data) { - if (data->anchor) - return 0; + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; + kvm_pte_t *childp = kvm_pte_follow(ctx->old, mm_ops); + int ret; - if (!kvm_block_mapping_supported(addr, end, data->phys, level)) + if (!stage2_leaf_mapping_allowed(ctx, data)) return 0; - data->childp = kvm_pte_follow(*ptep, data->mm_ops); - kvm_clear_pte(ptep); + ret = stage2_map_walker_try_leaf(ctx, data); + if (ret) + return ret; - /* - * Invalidate the whole stage-2, as we may have numerous leaf - * entries below us which would otherwise need invalidating - * individually. - */ - kvm_call_hyp(__kvm_tlb_flush_vmid, data->mmu); - data->anchor = ptep; + mm_ops->free_unlinked_table(childp, ctx->level); return 0; } -static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, +static int stage2_map_walk_leaf(const struct kvm_pgtable_visit_ctx *ctx, struct stage2_map_data *data) { - struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops; - kvm_pte_t *childp, pte = *ptep; + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; + kvm_pte_t *childp, new; int ret; - if (data->anchor) { - if (stage2_pte_is_counted(pte)) - mm_ops->put_page(ptep); - - return 0; - } - - ret = stage2_map_walker_try_leaf(addr, end, level, ptep, data); + ret = stage2_map_walker_try_leaf(ctx, data); if (ret != -E2BIG) return ret; - if (WARN_ON(level == KVM_PGTABLE_MAX_LEVELS - 1)) + if (WARN_ON(ctx->level == KVM_PGTABLE_LAST_LEVEL)) return -EINVAL; if (!data->memcache) @@ -685,98 +1029,62 @@ static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, if (!childp) return -ENOMEM; + if (!stage2_try_break_pte(ctx, data->mmu)) { + mm_ops->put_page(childp); + return -EAGAIN; + } + /* * If we've run into an existing block mapping then replace it with * a table. Accesses beyond 'end' that fall within the new table * will be mapped lazily. */ - if (stage2_pte_is_counted(pte)) - stage2_put_pte(ptep, data->mmu, addr, level, mm_ops); - - kvm_set_table_pte(ptep, childp, mm_ops); - mm_ops->get_page(ptep); + new = kvm_init_table_pte(childp, mm_ops); + stage2_make_pte(ctx, new); return 0; } -static int stage2_map_walk_table_post(u64 addr, u64 end, u32 level, - kvm_pte_t *ptep, - struct stage2_map_data *data) -{ - struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops; - kvm_pte_t *childp; - int ret = 0; - - if (!data->anchor) - return 0; - - if (data->anchor == ptep) { - childp = data->childp; - data->anchor = NULL; - data->childp = NULL; - ret = stage2_map_walk_leaf(addr, end, level, ptep, data); - } else { - childp = kvm_pte_follow(*ptep, mm_ops); - } - - mm_ops->put_page(childp); - mm_ops->put_page(ptep); - - return ret; -} - /* - * This is a little fiddly, as we use all three of the walk flags. The idea - * is that the TABLE_PRE callback runs for table entries on the way down, - * looking for table entries which we could conceivably replace with a - * block entry for this mapping. If it finds one, then it sets the 'anchor' - * field in 'struct stage2_map_data' to point at the table entry, before - * clearing the entry to zero and descending into the now detached table. + * The TABLE_PRE callback runs for table entries on the way down, looking + * for table entries which we could conceivably replace with a block entry + * for this mapping. If it finds one it replaces the entry and calls + * kvm_pgtable_mm_ops::free_unlinked_table() to tear down the detached table. * - * The behaviour of the LEAF callback then depends on whether or not the - * anchor has been set. If not, then we're not using a block mapping higher - * up the table and we perform the mapping at the existing leaves instead. - * If, on the other hand, the anchor _is_ set, then we drop references to - * all valid leaves so that the pages beneath the anchor can be freed. - * - * Finally, the TABLE_POST callback does nothing if the anchor has not - * been set, but otherwise frees the page-table pages while walking back up - * the page-table, installing the block entry when it revisits the anchor - * pointer and clearing the anchor to NULL. + * Otherwise, the LEAF callback performs the mapping at the existing leaves + * instead. */ -static int stage2_map_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, void * const arg) +static int stage2_map_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { - struct stage2_map_data *data = arg; + struct stage2_map_data *data = ctx->arg; - switch (flag) { + switch (visit) { case KVM_PGTABLE_WALK_TABLE_PRE: - return stage2_map_walk_table_pre(addr, end, level, ptep, data); + return stage2_map_walk_table_pre(ctx, data); case KVM_PGTABLE_WALK_LEAF: - return stage2_map_walk_leaf(addr, end, level, ptep, data); - case KVM_PGTABLE_WALK_TABLE_POST: - return stage2_map_walk_table_post(addr, end, level, ptep, data); + return stage2_map_walk_leaf(ctx, data); + default: + return -EINVAL; } - - return -EINVAL; } int kvm_pgtable_stage2_map(struct kvm_pgtable *pgt, u64 addr, u64 size, u64 phys, enum kvm_pgtable_prot prot, - void *mc) + void *mc, enum kvm_pgtable_walk_flags flags) { int ret; struct stage2_map_data map_data = { .phys = ALIGN_DOWN(phys, PAGE_SIZE), .mmu = pgt->mmu, .memcache = mc, - .mm_ops = pgt->mm_ops, + .force_pte = pgt->force_pte_cb && pgt->force_pte_cb(addr, addr + size, prot), }; struct kvm_pgtable_walker walker = { .cb = stage2_map_walker, - .flags = KVM_PGTABLE_WALK_TABLE_PRE | - KVM_PGTABLE_WALK_LEAF | - KVM_PGTABLE_WALK_TABLE_POST, + .flags = flags | + KVM_PGTABLE_WALK_TABLE_PRE | + KVM_PGTABLE_WALK_LEAF, .arg = &map_data, }; @@ -797,17 +1105,16 @@ int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size, { int ret; struct stage2_map_data map_data = { - .phys = KVM_PHYS_INVALID, .mmu = pgt->mmu, .memcache = mc, - .mm_ops = pgt->mm_ops, .owner_id = owner_id, + .force_pte = true, + .annotation = true, }; struct kvm_pgtable_walker walker = { .cb = stage2_map_walker, .flags = KVM_PGTABLE_WALK_TABLE_PRE | - KVM_PGTABLE_WALK_LEAF | - KVM_PGTABLE_WALK_TABLE_POST, + KVM_PGTABLE_WALK_LEAF, .arg = &map_data, }; @@ -818,30 +1125,29 @@ int kvm_pgtable_stage2_set_owner(struct kvm_pgtable *pgt, u64 addr, u64 size, return ret; } -static int stage2_unmap_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, - void * const arg) +static int stage2_unmap_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { - struct kvm_pgtable *pgt = arg; + struct kvm_pgtable *pgt = ctx->arg; struct kvm_s2_mmu *mmu = pgt->mmu; - struct kvm_pgtable_mm_ops *mm_ops = pgt->mm_ops; - kvm_pte_t pte = *ptep, *childp = NULL; + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; + kvm_pte_t *childp = NULL; bool need_flush = false; - if (!kvm_pte_valid(pte)) { - if (stage2_pte_is_counted(pte)) { - kvm_clear_pte(ptep); - mm_ops->put_page(ptep); + if (!kvm_pte_valid(ctx->old)) { + if (stage2_pte_is_counted(ctx->old)) { + kvm_clear_pte(ctx->ptep); + mm_ops->put_page(ctx->ptep); } return 0; } - if (kvm_pte_table(pte, level)) { - childp = kvm_pte_follow(pte, mm_ops); + if (kvm_pte_table(ctx->old, ctx->level)) { + childp = kvm_pte_follow(ctx->old, mm_ops); if (mm_ops->page_count(childp) != 1) return 0; - } else if (stage2_pte_cacheable(pgt, pte)) { + } else if (stage2_pte_cacheable(pgt, ctx->old)) { need_flush = !stage2_has_fwb(pgt); } @@ -850,15 +1156,11 @@ static int stage2_unmap_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, * block entry and rely on the remaining portions being faulted * back lazily. */ - stage2_put_pte(ptep, mmu, addr, level, mm_ops); + stage2_unmap_put_pte(ctx, mmu, mm_ops); - if (need_flush) { - kvm_pte_t *pte_follow = kvm_pte_follow(pte, mm_ops); - - dcache_clean_inval_poc((unsigned long)pte_follow, - (unsigned long)pte_follow + - kvm_granule_size(level)); - } + if (need_flush && mm_ops->dcache_clean_inval_poc) + mm_ops->dcache_clean_inval_poc(kvm_pte_follow(ctx->old, mm_ops), + kvm_granule_size(ctx->level)); if (childp) mm_ops->put_page(childp); @@ -868,35 +1170,39 @@ static int stage2_unmap_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, int kvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size) { + int ret; struct kvm_pgtable_walker walker = { .cb = stage2_unmap_walker, .arg = pgt, .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST, }; - return kvm_pgtable_walk(pgt, addr, size, &walker); + ret = kvm_pgtable_walk(pgt, addr, size, &walker); + if (stage2_unmap_defer_tlb_flush(pgt)) + /* Perform the deferred TLB invalidations */ + kvm_tlb_flush_vmid_range(pgt->mmu, addr, size); + + return ret; } struct stage2_attr_data { kvm_pte_t attr_set; kvm_pte_t attr_clr; kvm_pte_t pte; - u32 level; - struct kvm_pgtable_mm_ops *mm_ops; + s8 level; }; -static int stage2_attr_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, - void * const arg) +static int stage2_attr_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { - kvm_pte_t pte = *ptep; - struct stage2_attr_data *data = arg; - struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops; + kvm_pte_t pte = ctx->old; + struct stage2_attr_data *data = ctx->arg; + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; - if (!kvm_pte_valid(pte)) - return 0; + if (!kvm_pte_valid(ctx->old)) + return -EAGAIN; - data->level = level; + data->level = ctx->level; data->pte = pte; pte &= ~data->attr_clr; pte |= data->attr_set; @@ -912,10 +1218,12 @@ static int stage2_attr_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, * stage-2 PTE if we are going to add executable permission. */ if (mm_ops->icache_inval_pou && - stage2_pte_executable(pte) && !stage2_pte_executable(*ptep)) + stage2_pte_executable(pte) && !stage2_pte_executable(ctx->old)) mm_ops->icache_inval_pou(kvm_pte_follow(pte, mm_ops), - kvm_granule_size(level)); - WRITE_ONCE(*ptep, pte); + kvm_granule_size(ctx->level)); + + if (!stage2_try_set_pte(ctx, pte)) + return -EAGAIN; } return 0; @@ -924,19 +1232,18 @@ static int stage2_attr_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, static int stage2_update_leaf_attrs(struct kvm_pgtable *pgt, u64 addr, u64 size, kvm_pte_t attr_set, kvm_pte_t attr_clr, kvm_pte_t *orig_pte, - u32 *level) + s8 *level, enum kvm_pgtable_walk_flags flags) { int ret; kvm_pte_t attr_mask = KVM_PTE_LEAF_ATTR_LO | KVM_PTE_LEAF_ATTR_HI; struct stage2_attr_data data = { .attr_set = attr_set & attr_mask, .attr_clr = attr_clr & attr_mask, - .mm_ops = pgt->mm_ops, }; struct kvm_pgtable_walker walker = { .cb = stage2_attr_walker, .arg = &data, - .flags = KVM_PGTABLE_WALK_LEAF, + .flags = flags | KVM_PGTABLE_WALK_LEAF, }; ret = kvm_pgtable_walk(pgt, addr, size, &walker); @@ -955,45 +1262,79 @@ int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size) { return stage2_update_leaf_attrs(pgt, addr, size, 0, KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W, - NULL, NULL); + NULL, NULL, 0); } -kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr) +void kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr, + enum kvm_pgtable_walk_flags flags) { - kvm_pte_t pte = 0; - stage2_update_leaf_attrs(pgt, addr, 1, KVM_PTE_LEAF_ATTR_LO_S2_AF, 0, - &pte, NULL); - dsb(ishst); - return pte; + int ret; + + ret = stage2_update_leaf_attrs(pgt, addr, 1, KVM_PTE_LEAF_ATTR_LO_S2_AF, 0, + NULL, NULL, flags); + if (!ret) + dsb(ishst); } -kvm_pte_t kvm_pgtable_stage2_mkold(struct kvm_pgtable *pgt, u64 addr) +struct stage2_age_data { + bool mkold; + bool young; +}; + +static int stage2_age_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { - kvm_pte_t pte = 0; - stage2_update_leaf_attrs(pgt, addr, 1, 0, KVM_PTE_LEAF_ATTR_LO_S2_AF, - &pte, NULL); + kvm_pte_t new = ctx->old & ~KVM_PTE_LEAF_ATTR_LO_S2_AF; + struct stage2_age_data *data = ctx->arg; + + if (!kvm_pte_valid(ctx->old) || new == ctx->old) + return 0; + + data->young = true; + + /* + * stage2_age_walker() is always called while holding the MMU lock for + * write, so this will always succeed. Nonetheless, this deliberately + * follows the race detection pattern of the other stage-2 walkers in + * case the locking mechanics of the MMU notifiers is ever changed. + */ + if (data->mkold && !stage2_try_set_pte(ctx, new)) + return -EAGAIN; + /* * "But where's the TLBI?!", you scream. * "Over in the core code", I sigh. * * See the '->clear_flush_young()' callback on the KVM mmu notifier. */ - return pte; + return 0; } -bool kvm_pgtable_stage2_is_young(struct kvm_pgtable *pgt, u64 addr) +bool kvm_pgtable_stage2_test_clear_young(struct kvm_pgtable *pgt, u64 addr, + u64 size, bool mkold) { - kvm_pte_t pte = 0; - stage2_update_leaf_attrs(pgt, addr, 1, 0, 0, &pte, NULL); - return pte & KVM_PTE_LEAF_ATTR_LO_S2_AF; + struct stage2_age_data data = { + .mkold = mkold, + }; + struct kvm_pgtable_walker walker = { + .cb = stage2_age_walker, + .arg = &data, + .flags = KVM_PGTABLE_WALK_LEAF, + }; + + WARN_ON(kvm_pgtable_walk(pgt, addr, size, &walker)); + return data.young; } int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr, - enum kvm_pgtable_prot prot) + enum kvm_pgtable_prot prot, enum kvm_pgtable_walk_flags flags) { + kvm_pte_t xn = 0, set = 0, clr = 0; + s8 level; int ret; - u32 level; - kvm_pte_t set = 0, clr = 0; + + if (prot & KVM_PTE_LEAF_ATTR_HI_SW) + return -EINVAL; if (prot & KVM_PGTABLE_PROT_R) set |= KVM_PTE_LEAF_ATTR_LO_S2_S2AP_R; @@ -1001,31 +1342,31 @@ int kvm_pgtable_stage2_relax_perms(struct kvm_pgtable *pgt, u64 addr, if (prot & KVM_PGTABLE_PROT_W) set |= KVM_PTE_LEAF_ATTR_LO_S2_S2AP_W; - if (prot & KVM_PGTABLE_PROT_X) - clr |= KVM_PTE_LEAF_ATTR_HI_S2_XN; + ret = stage2_set_xn_attr(prot, &xn); + if (ret) + return ret; - ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, NULL, &level); - if (!ret) - kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, pgt->mmu, addr, level); + set |= xn & KVM_PTE_LEAF_ATTR_HI_S2_XN; + clr |= ~xn & KVM_PTE_LEAF_ATTR_HI_S2_XN; + + ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, NULL, &level, flags); + if (!ret || ret == -EAGAIN) + kvm_call_hyp(__kvm_tlb_flush_vmid_ipa_nsh, pgt->mmu, addr, level); return ret; } -static int stage2_flush_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, - void * const arg) +static int stage2_flush_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) { - struct kvm_pgtable *pgt = arg; + struct kvm_pgtable *pgt = ctx->arg; struct kvm_pgtable_mm_ops *mm_ops = pgt->mm_ops; - kvm_pte_t pte = *ptep; - kvm_pte_t *pte_follow; - if (!kvm_pte_valid(pte) || !stage2_pte_cacheable(pgt, pte)) + if (!stage2_pte_cacheable(pgt, ctx->old)) return 0; - pte_follow = kvm_pte_follow(pte, mm_ops); - dcache_clean_inval_poc((unsigned long)pte_follow, - (unsigned long)pte_follow + - kvm_granule_size(level)); + if (mm_ops->dcache_clean_inval_poc) + mm_ops->dcache_clean_inval_poc(kvm_pte_follow(ctx->old, mm_ops), + kvm_granule_size(ctx->level)); return 0; } @@ -1043,136 +1384,296 @@ int kvm_pgtable_stage2_flush(struct kvm_pgtable *pgt, u64 addr, u64 size) return kvm_pgtable_walk(pgt, addr, size, &walker); } -int kvm_pgtable_stage2_init_flags(struct kvm_pgtable *pgt, struct kvm_arch *arch, - struct kvm_pgtable_mm_ops *mm_ops, - enum kvm_pgtable_stage2_flags flags) +kvm_pte_t *kvm_pgtable_stage2_create_unlinked(struct kvm_pgtable *pgt, + u64 phys, s8 level, + enum kvm_pgtable_prot prot, + void *mc, bool force_pte) +{ + struct stage2_map_data map_data = { + .phys = phys, + .mmu = pgt->mmu, + .memcache = mc, + .force_pte = force_pte, + }; + struct kvm_pgtable_walker walker = { + .cb = stage2_map_walker, + .flags = KVM_PGTABLE_WALK_LEAF | + KVM_PGTABLE_WALK_SKIP_BBM_TLBI | + KVM_PGTABLE_WALK_SKIP_CMO, + .arg = &map_data, + }; + /* + * The input address (.addr) is irrelevant for walking an + * unlinked table. Construct an ambiguous IA range to map + * kvm_granule_size(level) worth of memory. + */ + struct kvm_pgtable_walk_data data = { + .walker = &walker, + .addr = 0, + .end = kvm_granule_size(level), + }; + struct kvm_pgtable_mm_ops *mm_ops = pgt->mm_ops; + kvm_pte_t *pgtable; + int ret; + + if (!IS_ALIGNED(phys, kvm_granule_size(level))) + return ERR_PTR(-EINVAL); + + ret = stage2_set_prot_attr(pgt, prot, &map_data.attr); + if (ret) + return ERR_PTR(ret); + + pgtable = mm_ops->zalloc_page(mc); + if (!pgtable) + return ERR_PTR(-ENOMEM); + + ret = __kvm_pgtable_walk(&data, mm_ops, (kvm_pteref_t)pgtable, + level + 1); + if (ret) { + kvm_pgtable_stage2_free_unlinked(mm_ops, pgtable, level); + return ERR_PTR(ret); + } + + return pgtable; +} + +/* + * Get the number of page-tables needed to replace a block with a + * fully populated tree up to the PTE entries. Note that @level is + * interpreted as in "level @level entry". + */ +static int stage2_block_get_nr_page_tables(s8 level) +{ + switch (level) { + case 1: + return PTRS_PER_PTE + 1; + case 2: + return 1; + case 3: + return 0; + default: + WARN_ON_ONCE(level < KVM_PGTABLE_MIN_BLOCK_LEVEL || + level > KVM_PGTABLE_LAST_LEVEL); + return -EINVAL; + }; +} + +static int stage2_split_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) +{ + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; + struct kvm_mmu_memory_cache *mc = ctx->arg; + struct kvm_s2_mmu *mmu; + kvm_pte_t pte = ctx->old, new, *childp; + enum kvm_pgtable_prot prot; + s8 level = ctx->level; + bool force_pte; + int nr_pages; + u64 phys; + + /* No huge-pages exist at the last level */ + if (level == KVM_PGTABLE_LAST_LEVEL) + return 0; + + /* We only split valid block mappings */ + if (!kvm_pte_valid(pte)) + return 0; + + nr_pages = stage2_block_get_nr_page_tables(level); + if (nr_pages < 0) + return nr_pages; + + if (mc->nobjs >= nr_pages) { + /* Build a tree mapped down to the PTE granularity. */ + force_pte = true; + } else { + /* + * Don't force PTEs, so create_unlinked() below does + * not populate the tree up to the PTE level. The + * consequence is that the call will require a single + * page of level 2 entries at level 1, or a single + * page of PTEs at level 2. If we are at level 1, the + * PTEs will be created recursively. + */ + force_pte = false; + nr_pages = 1; + } + + if (mc->nobjs < nr_pages) + return -ENOMEM; + + mmu = container_of(mc, struct kvm_s2_mmu, split_page_cache); + phys = kvm_pte_to_phys(pte); + prot = kvm_pgtable_stage2_pte_prot(pte); + + childp = kvm_pgtable_stage2_create_unlinked(mmu->pgt, phys, + level, prot, mc, force_pte); + if (IS_ERR(childp)) + return PTR_ERR(childp); + + if (!stage2_try_break_pte(ctx, mmu)) { + kvm_pgtable_stage2_free_unlinked(mm_ops, childp, level); + return -EAGAIN; + } + + /* + * Note, the contents of the page table are guaranteed to be made + * visible before the new PTE is assigned because stage2_make_pte() + * writes the PTE using smp_store_release(). + */ + new = kvm_init_table_pte(childp, mm_ops); + stage2_make_pte(ctx, new); + return 0; +} + +int kvm_pgtable_stage2_split(struct kvm_pgtable *pgt, u64 addr, u64 size, + struct kvm_mmu_memory_cache *mc) +{ + struct kvm_pgtable_walker walker = { + .cb = stage2_split_walker, + .flags = KVM_PGTABLE_WALK_LEAF, + .arg = mc, + }; + int ret; + + ret = kvm_pgtable_walk(pgt, addr, size, &walker); + dsb(ishst); + return ret; +} + +int __kvm_pgtable_stage2_init(struct kvm_pgtable *pgt, struct kvm_s2_mmu *mmu, + struct kvm_pgtable_mm_ops *mm_ops, + enum kvm_pgtable_stage2_flags flags, + kvm_pgtable_force_pte_cb_t force_pte_cb) { size_t pgd_sz; - u64 vtcr = arch->vtcr; + u64 vtcr = mmu->vtcr; u32 ia_bits = VTCR_EL2_IPA(vtcr); u32 sl0 = FIELD_GET(VTCR_EL2_SL0_MASK, vtcr); - u32 start_level = VTCR_EL2_TGRAN_SL0_BASE - sl0; + s8 start_level = VTCR_EL2_TGRAN_SL0_BASE - sl0; pgd_sz = kvm_pgd_pages(ia_bits, start_level) * PAGE_SIZE; - pgt->pgd = mm_ops->zalloc_pages_exact(pgd_sz); + pgt->pgd = (kvm_pteref_t)mm_ops->zalloc_pages_exact(pgd_sz); if (!pgt->pgd) return -ENOMEM; pgt->ia_bits = ia_bits; pgt->start_level = start_level; pgt->mm_ops = mm_ops; - pgt->mmu = &arch->mmu; + pgt->mmu = mmu; pgt->flags = flags; + pgt->force_pte_cb = force_pte_cb; /* Ensure zeroed PGD pages are visible to the hardware walker */ dsb(ishst); return 0; } -static int stage2_free_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, - void * const arg) +size_t kvm_pgtable_stage2_pgd_size(u64 vtcr) { - struct kvm_pgtable_mm_ops *mm_ops = arg; - kvm_pte_t pte = *ptep; + u32 ia_bits = VTCR_EL2_IPA(vtcr); + u32 sl0 = FIELD_GET(VTCR_EL2_SL0_MASK, vtcr); + s8 start_level = VTCR_EL2_TGRAN_SL0_BASE - sl0; - if (!stage2_pte_is_counted(pte)) - return 0; + return kvm_pgd_pages(ia_bits, start_level) * PAGE_SIZE; +} + +static int stage2_free_leaf(const struct kvm_pgtable_visit_ctx *ctx) +{ + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; - mm_ops->put_page(ptep); + mm_ops->put_page(ctx->ptep); + return 0; +} + +static int stage2_free_table_post(const struct kvm_pgtable_visit_ctx *ctx) +{ + struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; + kvm_pte_t *childp = kvm_pte_follow(ctx->old, mm_ops); - if (kvm_pte_table(pte, level)) - mm_ops->put_page(kvm_pte_follow(pte, mm_ops)); + if (mm_ops->page_count(childp) != 1) + return 0; + /* + * Drop references and clear the now stale PTE to avoid rewalking the + * freed page table. + */ + mm_ops->put_page(ctx->ptep); + mm_ops->put_page(childp); + kvm_clear_pte(ctx->ptep); return 0; } -void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt) +static int stage2_free_walker(const struct kvm_pgtable_visit_ctx *ctx, + enum kvm_pgtable_walk_flags visit) +{ + if (!stage2_pte_is_counted(ctx->old)) + return 0; + + switch (visit) { + case KVM_PGTABLE_WALK_LEAF: + return stage2_free_leaf(ctx); + case KVM_PGTABLE_WALK_TABLE_POST: + return stage2_free_table_post(ctx); + default: + return -EINVAL; + } +} + +void kvm_pgtable_stage2_destroy_range(struct kvm_pgtable *pgt, + u64 addr, u64 size) { - size_t pgd_sz; struct kvm_pgtable_walker walker = { .cb = stage2_free_walker, .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST, - .arg = pgt->mm_ops, }; - WARN_ON(kvm_pgtable_walk(pgt, 0, BIT(pgt->ia_bits), &walker)); - pgd_sz = kvm_pgd_pages(pgt->ia_bits, pgt->start_level) * PAGE_SIZE; - pgt->mm_ops->free_pages_exact(pgt->pgd, pgd_sz); - pgt->pgd = NULL; + WARN_ON(kvm_pgtable_walk(pgt, addr, size, &walker)); } -#define KVM_PTE_LEAF_S2_COMPAT_MASK (KVM_PTE_LEAF_ATTR_S2_PERMS | \ - KVM_PTE_LEAF_ATTR_LO_S2_MEMATTR | \ - KVM_PTE_LEAF_ATTR_S2_IGNORED) - -static int stage2_check_permission_walker(u64 addr, u64 end, u32 level, - kvm_pte_t *ptep, - enum kvm_pgtable_walk_flags flag, - void * const arg) +void kvm_pgtable_stage2_destroy_pgd(struct kvm_pgtable *pgt) { - kvm_pte_t old_attr, pte = *ptep, *new_attr = arg; + size_t pgd_sz; + + pgd_sz = kvm_pgd_pages(pgt->ia_bits, pgt->start_level) * PAGE_SIZE; /* - * Compatible mappings are either invalid and owned by the page-table - * owner (whose id is 0), or valid with matching permission attributes. + * Since the pgtable is unlinked at this point, and not shared with + * other walkers, safely deference pgd with kvm_dereference_pteref_raw() */ - if (kvm_pte_valid(pte)) { - old_attr = pte & KVM_PTE_LEAF_S2_COMPAT_MASK; - if (old_attr != *new_attr) - return -EEXIST; - } else if (pte) { - return -EEXIST; - } + pgt->mm_ops->free_pages_exact(kvm_dereference_pteref_raw(pgt->pgd), pgd_sz); + pgt->pgd = NULL; +} - return 0; +void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt) +{ + kvm_pgtable_stage2_destroy_range(pgt, 0, BIT(pgt->ia_bits)); + kvm_pgtable_stage2_destroy_pgd(pgt); } -int kvm_pgtable_stage2_find_range(struct kvm_pgtable *pgt, u64 addr, - enum kvm_pgtable_prot prot, - struct kvm_mem_range *range) +void kvm_pgtable_stage2_free_unlinked(struct kvm_pgtable_mm_ops *mm_ops, void *pgtable, s8 level) { - kvm_pte_t attr; - struct kvm_pgtable_walker check_perm_walker = { - .cb = stage2_check_permission_walker, - .flags = KVM_PGTABLE_WALK_LEAF, - .arg = &attr, + kvm_pteref_t ptep = (kvm_pteref_t)pgtable; + struct kvm_pgtable_walker walker = { + .cb = stage2_free_walker, + .flags = KVM_PGTABLE_WALK_LEAF | + KVM_PGTABLE_WALK_TABLE_POST, }; - u64 granule, start, end; - u32 level; - int ret; - - ret = stage2_set_prot_attr(pgt, prot, &attr); - if (ret) - return ret; - attr &= KVM_PTE_LEAF_S2_COMPAT_MASK; - - for (level = pgt->start_level; level < KVM_PGTABLE_MAX_LEVELS; level++) { - granule = kvm_granule_size(level); - start = ALIGN_DOWN(addr, granule); - end = start + granule; - - if (!kvm_level_supports_block_mapping(level)) - continue; - - if (start < range->start || range->end < end) - continue; + struct kvm_pgtable_walk_data data = { + .walker = &walker, /* - * Check the presence of existing mappings with incompatible - * permissions within the current block range, and try one level - * deeper if one is found. + * At this point the IPA really doesn't matter, as the page + * table being traversed has already been removed from the stage + * 2. Set an appropriate range to cover the entire page table. */ - ret = kvm_pgtable_walk(pgt, start, granule, &check_perm_walker); - if (ret != -EEXIST) - break; - } + .addr = 0, + .end = kvm_granule_size(level), + }; - if (!ret) { - range->start = start; - range->end = end; - } + WARN_ON(__kvm_pgtable_walk(&data, mm_ops, ptep, level + 1)); - return ret; + WARN_ON(mm_ops->page_count(pgtable) != 1); + mm_ops->put_page(pgtable); } |