The page table walker does not visit block PTEs in post-order. But there
are some cases where doing so would be beneficial, for example: breaking a
1G block PTE into a full tree in post-order avoids visiting the new tree.
Allow post order visits of block PTEs. This will be used in a subsequent
commit for eagerly breaking huge pages.
Signed-off-by: Ricardo Koller <ricarkol@xxxxxxxxxx>
---
arch/arm64/include/asm/kvm_pgtable.h | 4 ++--
arch/arm64/kvm/hyp/nvhe/setup.c | 2 +-
arch/arm64/kvm/hyp/pgtable.c | 25 ++++++++++++-------------
3 files changed, 15 insertions(+), 16 deletions(-)
diff --git a/arch/arm64/include/asm/kvm_pgtable.h b/arch/arm64/include/asm/kvm_pgtable.h
index e2edeed462e8..d2e4a5032146 100644
--- a/arch/arm64/include/asm/kvm_pgtable.h
+++ b/arch/arm64/include/asm/kvm_pgtable.h
@@ -255,7 +255,7 @@ struct kvm_pgtable {
* entries.
* @KVM_PGTABLE_WALK_TABLE_PRE: Visit table entries before their
* children.
- * @KVM_PGTABLE_WALK_TABLE_POST: Visit table entries after their
+ * @KVM_PGTABLE_WALK_POST: Visit leaf or table entries after their
* children.
* @KVM_PGTABLE_WALK_SHARED: Indicates the page-tables may be shared
* with other software walkers.
@@ -263,7 +263,7 @@ struct kvm_pgtable {
enum kvm_pgtable_walk_flags {
KVM_PGTABLE_WALK_LEAF = BIT(0),
KVM_PGTABLE_WALK_TABLE_PRE = BIT(1),
- KVM_PGTABLE_WALK_TABLE_POST = BIT(2),
+ KVM_PGTABLE_WALK_POST = BIT(2),
KVM_PGTABLE_WALK_SHARED = BIT(3),
};
diff --git a/arch/arm64/kvm/hyp/nvhe/setup.c b/arch/arm64/kvm/hyp/nvhe/setup.c
index b47d969ae4d3..b0c1618d053b 100644
--- a/arch/arm64/kvm/hyp/nvhe/setup.c
+++ b/arch/arm64/kvm/hyp/nvhe/setup.c
@@ -265,7 +265,7 @@ static int fix_hyp_pgtable_refcnt(void)
{
struct kvm_pgtable_walker walker = {
.cb = fix_hyp_pgtable_refcnt_walker,
- .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST,
+ .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_POST,
.arg = pkvm_pgtable.mm_ops,
};
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index b16107bf917c..1b371f6dbac2 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -206,16 +206,15 @@ static inline int __kvm_pgtable_visit(struct kvm_pgtable_walk_data *data,
if (!table) {
data->addr = ALIGN_DOWN(data->addr, kvm_granule_size(level));
data->addr += kvm_granule_size(level);
- goto out;
+ } else {
+ 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;
}
- 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 (ctx.flags & KVM_PGTABLE_WALK_TABLE_POST)
- ret = kvm_pgtable_visitor_cb(data, &ctx, KVM_PGTABLE_WALK_TABLE_POST);
+ if (ctx.flags & KVM_PGTABLE_WALK_POST)
+ ret = kvm_pgtable_visitor_cb(data, &ctx, KVM_PGTABLE_WALK_POST);
out:
return ret;
@@ -494,7 +493,7 @@ u64 kvm_pgtable_hyp_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size)
struct kvm_pgtable_walker walker = {
.cb = hyp_unmap_walker,
.arg = &unmapped,
- .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST,
+ .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_POST,
};
if (!pgt->mm_ops->page_count)
@@ -542,7 +541,7 @@ void kvm_pgtable_hyp_destroy(struct kvm_pgtable *pgt)
{
struct kvm_pgtable_walker walker = {
.cb = hyp_free_walker,
- .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST,
+ .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_POST,
};
WARN_ON(kvm_pgtable_walk(pgt, 0, BIT(pgt->ia_bits), &walker));
@@ -1003,7 +1002,7 @@ int kvm_pgtable_stage2_unmap(struct kvm_pgtable *pgt, u64 addr, u64 size)
struct kvm_pgtable_walker walker = {
.cb = stage2_unmap_walker,
.arg = pgt,
- .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_TABLE_POST,
+ .flags = KVM_PGTABLE_WALK_LEAF | KVM_PGTABLE_WALK_POST,
};
return kvm_pgtable_walk(pgt, addr, size, &walker);
@@ -1234,7 +1233,7 @@ void kvm_pgtable_stage2_destroy(struct kvm_pgtable *pgt)
struct kvm_pgtable_walker walker = {
.cb = stage2_free_walker,
.flags = KVM_PGTABLE_WALK_LEAF |
- KVM_PGTABLE_WALK_TABLE_POST,
+ KVM_PGTABLE_WALK_POST,
};
WARN_ON(kvm_pgtable_walk(pgt, 0, BIT(pgt->ia_bits), &walker));
@@ -1249,7 +1248,7 @@ void kvm_pgtable_stage2_free_removed(struct kvm_pgtable_mm_ops *mm_ops, void *pg
struct kvm_pgtable_walker walker = {
.cb = stage2_free_walker,
.flags = KVM_PGTABLE_WALK_LEAF |
- KVM_PGTABLE_WALK_TABLE_POST,
+ KVM_PGTABLE_WALK_POST,
};
struct kvm_pgtable_walk_data data = {
.walker = &walker,
--
2.38.1.431.g37b22c650d-goog
