diff mbox series

[v2,4/6] KVM: arm64: Don't serialize if the access flag isn't set

Message ID 20221202185156.696189-5-oliver.upton@linux.dev (mailing list archive)
State New, archived
Headers show
Series KVM: arm64: Parallel access faults | expand

Commit Message

Oliver Upton Dec. 2, 2022, 6:51 p.m. UTC 
Of course, if the PTE wasn't changed then there are absolutely no
serialization requirements. Skip the DSB for an unsuccessful update to
the access flag.

Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
---
 arch/arm64/kvm/hyp/pgtable.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)
diff mbox series

Patch

diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index 204e59e05674..aa36d896bd8c 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -1116,10 +1116,14 @@  int kvm_pgtable_stage2_wrprotect(struct kvm_pgtable *pgt, u64 addr, u64 size)
 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,
-				 KVM_PGTABLE_WALK_HANDLE_FAULT);
-	dsb(ishst);
+	int ret;
+
+	ret = stage2_update_leaf_attrs(pgt, addr, 1, KVM_PTE_LEAF_ATTR_LO_S2_AF, 0,
+				       &pte, NULL,
+				       KVM_PGTABLE_WALK_HANDLE_FAULT);
+	if (!ret)
+		dsb(ishst);
+
 	return pte;
 }