From: Oliver Upton Date: Fri, 2 Dec 2022 18:51:54 +0000 (+0000) Subject: KVM: arm64: Don't serialize if the access flag isn't set X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=7d29a2407df612b0903cee94fc3469d7335b442c;p=linux.git KVM: arm64: Don't serialize if the access flag isn't set 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. Link: https://lore.kernel.org/r/20221202185156.696189-5-oliver.upton@linux.dev Signed-off-by: Oliver Upton --- diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c index 204e59e05674d..aa36d896bd8c6 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; }