[RFC PATCH 03/17] KVM: arm64: Return the next table from map callbacks

[Oliver Upton <oupton@google.com>]

The stage-2 and hyp stage-1 map walkers install new page tables during
their traversal. In order to support parallel table walks, make callers
return the next table to traverse.

Signed-off-by: Oliver Upton <oupton@google.com>
---
 arch/arm64/kvm/hyp/pgtable.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index ad911cd44425..5b64fbca8a93 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -205,13 +205,12 @@ static inline int __kvm_pgtable_visit(struct kvm_pgtable_walk_data *data,
 	if (!table && (flags & KVM_PGTABLE_WALK_LEAF)) {
 		ret = kvm_pgtable_visitor_cb(data, addr, level, ptep, &pte,
 					     KVM_PGTABLE_WALK_LEAF);
-		pte = *ptep;
-		table = kvm_pte_table(pte, level);
 	}
 
 	if (ret)
 		goto out;
 
+	table = kvm_pte_table(pte, level);
 	if (!table) {
 		data->addr = ALIGN_DOWN(data->addr, kvm_granule_size(level));
 		data->addr += kvm_granule_size(level);
@@ -429,6 +428,7 @@ static int hyp_map_walker(u64 addr, u64 end, u32 level, kvm_pte_t *ptep, kvm_pte
 
 	kvm_set_table_pte(ptep, childp, mm_ops);
 	mm_ops->get_page(ptep);
+	*old = *ptep;
 	return 0;
 }
 
@@ -828,7 +828,7 @@ static int stage2_map_walk_leaf(u64 addr, u64 end, u32 level, kvm_pte_t *ptep,
 
 	kvm_set_table_pte(ptep, childp, mm_ops);
 	mm_ops->get_page(ptep);
-
+	*old = *ptep;
 	return 0;
 }
 
-- 
2.36.0.rc0.470.gd361397f0d-goog