#define KVM_INVALID_PTE_OWNER_MASK GENMASK(9, 2)
#define KVM_MAX_OWNER_ID 1
+/*
+ * Used to indicate a pte for which a 'break-before-make' sequence is in
+ * progress.
+ */
+#define KVM_INVALID_PTE_LOCKED BIT(10)
+
struct kvm_pgtable_walk_data {
- struct kvm_pgtable *pgt;
struct kvm_pgtable_walker *walker;
u64 addr;
return phys < BIT(id_aa64mmfr0_parange_to_phys_shift(ID_AA64MMFR0_EL1_PARANGE_MAX));
}
-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))
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)
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;
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)
{
struct kvm_pgtable pgt = {
.start_level = start_level,
};
- return __kvm_pgd_page_idx(&pgt, -1ULL) + 1;
+ return kvm_pgd_page_idx(&pgt, -1ULL) + 1;
}
static bool kvm_pte_table(kvm_pte_t pte, u32 level)
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)
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 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, u32 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, u32 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,
+ .addr = data->addr,
+ .end = data->end,
+ .level = level,
+ .flags = flags,
+ };
+ int ret = 0;
+ 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);
- 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);
+ ctx.old = READ_ONCE(*ptep);
+ table = kvm_pte_table(ctx.old, level);
}
if (ret)
goto out;
}
- childp = kvm_pte_follow(pte, data->pgt->mm_ops);
- ret = __kvm_pgtable_walk(data, childp, level + 1);
+ childp = (kvm_pteref_t)kvm_pte_follow(ctx.old, mm_ops);
+ ret = __kvm_pgtable_walk(data, mm_ops, childp, level + 1);
if (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:
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, u32 level)
{
u32 idx;
int ret = 0;
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;
}
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)
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;
}
struct kvm_pgtable_walker *walker)
{
struct kvm_pgtable_walk_data walk_data = {
- .pgt = pgt,
.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;
- return _kvm_pgtable_walk(&walk_data);
+ r = _kvm_pgtable_walk(pgt, &walk_data);
+ kvm_pgtable_walk_end(walker);
+
+ return r;
}
struct leaf_walk_data {
u32 level;
};
-static int leaf_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
- enum kvm_pgtable_walk_flags flag, void * const arg)
+static int leaf_walker(const struct kvm_pgtable_visit_ctx *ctx,
+ enum kvm_pgtable_walk_flags visit)
{
- struct leaf_walk_data *data = arg;
+ struct leaf_walk_data *data = ctx->arg;
- data->pte = *ptep;
- data->level = level;
+ data->pte = ctx->old;
+ data->level = ctx->level;
return 0;
}
struct hyp_map_data {
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)
return prot;
}
-static bool hyp_map_walker_try_leaf(u64 addr, u64 end, u32 level,
- kvm_pte_t *ptep, struct hyp_map_data *data)
+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;
+ kvm_pte_t new;
+ u64 granule = kvm_granule_size(ctx->level), phys = data->phys;
- if (!kvm_block_mapping_supported(addr, end, phys, level))
+ if (!kvm_block_mapping_supported(ctx, phys))
return false;
data->phys += granule;
- new = kvm_init_valid_leaf_pte(phys, data->attr, level);
- if (old == new)
+ new = kvm_init_valid_leaf_pte(phys, data->attr, ctx->level);
+ if (ctx->old == new)
return true;
- if (!kvm_pte_valid(old))
- data->mm_ops->get_page(ptep);
- else if (WARN_ON((old ^ new) & ~KVM_PTE_LEAF_ATTR_HI_SW))
+ 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;
- smp_store_release(ptep, new);
+ 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_MAX_LEVELS - 1))
return -EINVAL;
childp = (kvm_pte_t *)mm_ops->zalloc_page(NULL);
if (!childp)
return -ENOMEM;
- kvm_set_table_pte(ptep, childp, mm_ops);
- mm_ops->get_page(ptep);
+ new = kvm_init_table_pte(childp, mm_ops);
+ mm_ops->get_page(ctx->ptep);
+ smp_store_release(ctx->ptep, new);
+
return 0;
}
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,
return ret;
}
-struct hyp_unmap_data {
- u64 unmapped;
- struct kvm_pgtable_mm_ops *mm_ops;
-};
-
-static int hyp_unmap_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
- enum kvm_pgtable_walk_flags flag, void * const arg)
+static int hyp_unmap_walker(const struct kvm_pgtable_visit_ctx *ctx,
+ enum kvm_pgtable_walk_flags visit)
{
- kvm_pte_t pte = *ptep, *childp = NULL;
- u64 granule = kvm_granule_size(level);
- struct hyp_unmap_data *data = arg;
- struct kvm_pgtable_mm_ops *mm_ops = data->mm_ops;
+ 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(pte))
+ if (!kvm_pte_valid(ctx->old))
return -EINVAL;
- 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;
- kvm_clear_pte(ptep);
+ kvm_clear_pte(ctx->ptep);
dsb(ishst);
- __tlbi_level(vae2is, __TLBI_VADDR(addr, 0), level);
+ __tlbi_level(vae2is, __TLBI_VADDR(ctx->addr, 0), ctx->level);
} else {
- if (end - addr < granule)
+ if (ctx->end - ctx->addr < granule)
return -EINVAL;
- kvm_clear_pte(ptep);
+ kvm_clear_pte(ctx->ptep);
dsb(ishst);
- __tlbi_level(vale2is, __TLBI_VADDR(addr, 0), level);
- data->unmapped += granule;
+ __tlbi_level(vale2is, __TLBI_VADDR(ctx->addr, 0), ctx->level);
+ *unmapped += granule;
}
dsb(ish);
isb();
- mm_ops->put_page(ptep);
+ mm_ops->put_page(ctx->ptep);
if (childp)
mm_ops->put_page(childp);
u64 kvm_pgtable_hyp_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size)
{
- struct hyp_unmap_data unmap_data = {
- .mm_ops = pgt->mm_ops,
- };
+ u64 unmapped = 0;
struct kvm_pgtable_walker walker = {
.cb = hyp_unmap_walker,
- .arg = &unmap_data,
+ .arg = &unmapped,
.flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST,
};
return 0;
kvm_pgtable_walk(pgt, addr, size, &walker);
- return unmap_data.unmapped;
+ return unmapped;
}
int kvm_pgtable_hyp_init(struct kvm_pgtable *pgt, u32 va_bits,
{
u64 levels = ARM64_HW_PGTABLE_LEVELS(va_bits);
- 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;
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;
- kvm_pte_t pte = *ptep;
+ struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
- if (!kvm_pte_valid(pte))
+ if (!kvm_pte_valid(ctx->old))
return 0;
- mm_ops->put_page(ptep);
+ mm_ops->put_page(ctx->ptep);
- if (kvm_pte_table(pte, level))
- mm_ops->put_page(kvm_pte_follow(pte, mm_ops));
+ if (kvm_pte_table(ctx->old, ctx->level))
+ mm_ops->put_page(kvm_pte_follow(ctx->old, mm_ops));
return 0;
}
struct kvm_pgtable_walker walker = {
.cb = hyp_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));
- pgt->mm_ops->put_page(pgt->pgd);
+ pgt->mm_ops->put_page(kvm_dereference_pteref(&walker, pgt->pgd));
pgt->pgd = NULL;
}
struct kvm_s2_mmu *mmu;
void *memcache;
- struct kvm_pgtable_mm_ops *mm_ops;
-
/* Force mappings to page granularity */
bool force_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;
+
+ /*
+ * Perform the appropriate TLB invalidation based on the evicted pte
+ * value (if any).
+ */
+ if (kvm_pte_table(ctx->old, ctx->level))
+ kvm_call_hyp(__kvm_tlb_flush_vmid, mmu);
+ 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 void stage2_put_pte(const struct kvm_pgtable_visit_ctx *ctx, struct kvm_s2_mmu *mmu,
+ struct kvm_pgtable_mm_ops *mm_ops)
{
/*
* Clear the existing PTE, and perform break-before-make with
* TLB maintenance if it was valid.
*/
- if (kvm_pte_valid(*ptep)) {
- kvm_clear_pte(ptep);
- kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, mmu, addr, level);
+ if (kvm_pte_valid(ctx->old)) {
+ kvm_clear_pte(ctx->ptep);
+ 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)
return !(pte & KVM_PTE_LEAF_ATTR_HI_S2_XN);
}
-static bool stage2_leaf_mapping_allowed(u64 addr, u64 end, u32 level,
+static bool stage2_leaf_mapping_allowed(const struct kvm_pgtable_visit_ctx *ctx,
struct stage2_map_data *data)
{
- if (data->force_pte && (level < (KVM_PGTABLE_MAX_LEVELS - 1)))
+ if (data->force_pte && (ctx->level < (KVM_PGTABLE_MAX_LEVELS - 1)))
return false;
- return kvm_block_mapping_supported(addr, end, data->phys, level);
+ return kvm_block_mapping_supported(ctx, data->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 granule = kvm_granule_size(ctx->level), phys = data->phys;
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 (!stage2_leaf_mapping_allowed(addr, end, level, data))
+ 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);
+ 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;
+ /*
+ * 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;
- stage2_put_pte(ptep, data->mmu, addr, level, mm_ops);
- }
+ 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 (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);
+ stage2_make_pte(ctx, new);
+
if (kvm_phys_is_valid(phys))
data->phys += granule;
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 (!stage2_leaf_mapping_allowed(addr, end, level, data))
+ 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_removed_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_MAX_LEVELS - 1))
return -EINVAL;
if (!data->memcache)
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_removed_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,
};
.phys = KVM_PHYS_INVALID,
.mmu = pgt->mmu,
.memcache = mc,
- .mm_ops = pgt->mm_ops,
.owner_id = owner_id,
.force_pte = 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,
};
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);
}
* block entry and rely on the remaining portions being faulted
* back lazily.
*/
- stage2_put_pte(ptep, mmu, addr, level, mm_ops);
+ stage2_put_pte(ctx, mmu, mm_ops);
if (need_flush && mm_ops->dcache_clean_inval_poc)
- mm_ops->dcache_clean_inval_poc(kvm_pte_follow(pte, mm_ops),
- kvm_granule_size(level));
+ 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);
kvm_pte_t attr_clr;
kvm_pte_t pte;
u32 level;
- struct kvm_pgtable_mm_ops *mm_ops;
};
-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))
+ if (!kvm_pte_valid(ctx->old))
return 0;
- data->level = level;
+ data->level = ctx->level;
data->pte = pte;
pte &= ~data->attr_clr;
pte |= data->attr_set;
* 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;
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)
+ u32 *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);
{
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)
{
kvm_pte_t pte = 0;
stage2_update_leaf_attrs(pgt, addr, 1, KVM_PTE_LEAF_ATTR_LO_S2_AF, 0,
- &pte, NULL);
+ &pte, NULL, 0);
dsb(ishst);
return pte;
}
{
kvm_pte_t pte = 0;
stage2_update_leaf_attrs(pgt, addr, 1, 0, KVM_PTE_LEAF_ATTR_LO_S2_AF,
- &pte, NULL);
+ &pte, NULL, 0);
/*
* "But where's the TLBI?!", you scream.
* "Over in the core code", I sigh.
bool kvm_pgtable_stage2_is_young(struct kvm_pgtable *pgt, u64 addr)
{
kvm_pte_t pte = 0;
- stage2_update_leaf_attrs(pgt, addr, 1, 0, 0, &pte, NULL);
+ stage2_update_leaf_attrs(pgt, addr, 1, 0, 0, &pte, NULL, 0);
return pte & KVM_PTE_LEAF_ATTR_LO_S2_AF;
}
if (prot & KVM_PGTABLE_PROT_X)
clr |= KVM_PTE_LEAF_ATTR_HI_S2_XN;
- ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, NULL, &level);
+ ret = stage2_update_leaf_attrs(pgt, addr, 1, set, clr, NULL, &level,
+ KVM_PGTABLE_WALK_SHARED);
if (!ret)
kvm_call_hyp(__kvm_tlb_flush_vmid_ipa, 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;
- if (!kvm_pte_valid(pte) || !stage2_pte_cacheable(pgt, pte))
+ if (!kvm_pte_valid(ctx->old) || !stage2_pte_cacheable(pgt, ctx->old))
return 0;
if (mm_ops->dcache_clean_inval_poc)
- mm_ops->dcache_clean_inval_poc(kvm_pte_follow(pte, mm_ops),
- kvm_granule_size(level));
+ mm_ops->dcache_clean_inval_poc(kvm_pte_follow(ctx->old, mm_ops),
+ kvm_granule_size(ctx->level));
return 0;
}
u32 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;
return kvm_pgd_pages(ia_bits, start_level) * PAGE_SIZE;
}
-static int stage2_free_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
- enum kvm_pgtable_walk_flags flag,
- void * const arg)
+static int stage2_free_walker(const struct kvm_pgtable_visit_ctx *ctx,
+ enum kvm_pgtable_walk_flags visit)
{
- struct kvm_pgtable_mm_ops *mm_ops = arg;
- kvm_pte_t pte = *ptep;
+ struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops;
- if (!stage2_pte_is_counted(pte))
+ if (!stage2_pte_is_counted(ctx->old))
return 0;
- mm_ops->put_page(ptep);
+ mm_ops->put_page(ctx->ptep);
- if (kvm_pte_table(pte, level))
- mm_ops->put_page(kvm_pte_follow(pte, mm_ops));
+ if (kvm_pte_table(ctx->old, ctx->level))
+ mm_ops->put_page(kvm_pte_follow(ctx->old, mm_ops));
return 0;
}
.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->mm_ops->free_pages_exact(kvm_dereference_pteref(&walker, pgt->pgd), pgd_sz);
pgt->pgd = NULL;
}
+
+void kvm_pgtable_stage2_free_removed(struct kvm_pgtable_mm_ops *mm_ops, void *pgtable, u32 level)
+{
+ 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,
+ };
+ struct kvm_pgtable_walk_data data = {
+ .walker = &walker,
+
+ /*
+ * 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.
+ */
+ .addr = 0,
+ .end = kvm_granule_size(level),
+ };
+
+ WARN_ON(__kvm_pgtable_walk(&data, mm_ops, ptep, level + 1));
+}
projects / linux-2.6-microblaze.git / blobdiff