Commit 7d29a240 authored by Oliver Upton's avatar Oliver Upton
Browse files

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: default avatarOliver Upton <oliver.upton@linux.dev>
parent 76259cca

arch/arm64/kvm/hyp/pgtable.c

+8 −4
Original line number Diff line number Diff line
@@ -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,

	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;

}