To prepare the ground for allowing hyp stage-1 mappings to be removed at
run-time, update the KVM page-table code to maintain a correct refcount
using the ->{get,put}_page() function callbacks.Signed-off-by: Quentin Perret <[email protected]> --- arch/arm64/kvm/hyp/pgtable.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-) diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index f8ceebe4982e..768a58835153 100644 --- a/arch/arm64/kvm/hyp/pgtable.c +++ b/arch/arm64/kvm/hyp/pgtable.c @@ -408,8 +408,10 @@ static bool hyp_map_walker_try_leaf(u64 addr, u64 end, u32 level, return false; new = kvm_init_valid_leaf_pte(phys, data->attr, level); - if (hyp_pte_needs_update(old, new)) + if (hyp_pte_needs_update(old, new)) { smp_store_release(ptep, new); + data->mm_ops->get_page(ptep); + } data->phys += granule; return true; @@ -433,6 +435,7 @@ static int hyp_map_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, return -ENOMEM; kvm_set_table_pte(ptep, childp, mm_ops); + mm_ops->get_page(ptep); return 0; } @@ -482,8 +485,16 @@ static int hyp_free_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, enum kvm_pgtable_walk_flags flag, void * const arg) { struct kvm_pgtable_mm_ops *mm_ops = arg; + kvm_pte_t pte = *ptep; + + if (!kvm_pte_valid(pte)) + return 0; + + mm_ops->put_page(ptep); + + if (kvm_pte_table(pte, level)) + mm_ops->put_page(kvm_pte_follow(pte, mm_ops)); - mm_ops->put_page((void *)kvm_pte_follow(*ptep, mm_ops)); return 0; } @@ -491,7 +502,7 @@ void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt) { struct kvm_pgtable_walker walker = { .cb = hyp_free_walker, - .flags = KVM_PGTABLE_WALK_TABLE_POST, + .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST, .arg = pgt->mm_ops, }; -- 2.33.0.882.g93a45727a2-goog _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
