diff options
Diffstat (limited to 'arch/arm64/kvm/hyp/pgtable.c')
| -rw-r--r-- | arch/arm64/kvm/hyp/pgtable.c | 38 |
1 files changed, 32 insertions, 6 deletions
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index c351b4abd5db..6d6a23f7dedb 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -1535,20 +1535,46 @@ size_t kvm_pgtable_stage2_pgd_size(u64 vtcr) return kvm_pgd_pages(ia_bits, start_level) * PAGE_SIZE; } -static int stage2_free_walker(const struct kvm_pgtable_visit_ctx *ctx, - enum kvm_pgtable_walk_flags visit) +static int stage2_free_leaf(const struct kvm_pgtable_visit_ctx *ctx) { struct kvm_pgtable_mm_ops *mm_ops = ctx->mm_ops; - if (!stage2_pte_is_counted(ctx->old)) + 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 (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; +} - if (kvm_pte_table(ctx->old, ctx->level)) - mm_ops->put_page(kvm_pte_follow(ctx->old, mm_ops)); +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; - 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(struct kvm_pgtable *pgt) |