As the underlying software walkers are able to traverse and update
stage-2 in parallel there is no need to serialize access faults.
Only take the read lock when handling an access fault.
Signed-off-by: Oliver Upton <[email protected]>
---
arch/arm64/kvm/hyp/pgtable.c | 3 ++-
arch/arm64/kvm/mmu.c | 4 ++--
2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/kvm/hyp/pgtable.c b/arch/arm64/kvm/hyp/pgtable.c
index aa36d896bd8c..30575b5f5dcd 100644
--- a/arch/arm64/kvm/hyp/pgtable.c
+++ b/arch/arm64/kvm/hyp/pgtable.c
@@ -1120,7 +1120,8 @@ kvm_pte_t kvm_pgtable_stage2_mkyoung(struct kvm_pgtable *pgt, u64 addr)
ret = stage2_update_leaf_attrs(pgt, addr, 1, KVM_PTE_LEAF_ATTR_LO_S2_AF, 0,
&pte, NULL,
- KVM_PGTABLE_WALK_HANDLE_FAULT);
+ KVM_PGTABLE_WALK_HANDLE_FAULT |
+ KVM_PGTABLE_WALK_SHARED);
if (!ret)
dsb(ishst);
diff --git a/arch/arm64/kvm/mmu.c b/arch/arm64/kvm/mmu.c
index dd8c715f0775..25e18e1d9a15 100644
--- a/arch/arm64/kvm/mmu.c
+++ b/arch/arm64/kvm/mmu.c
@@ -1406,10 +1406,10 @@ static void handle_access_fault(struct kvm_vcpu *vcpu, phys_addr_t fault_ipa)
trace_kvm_access_fault(fault_ipa);
- write_lock(&vcpu->kvm->mmu_lock);
+ read_lock(&vcpu->kvm->mmu_lock);
mmu = vcpu->arch.hw_mmu;
pte = kvm_pgtable_stage2_mkyoung(mmu->pgt, fault_ipa);
- write_unlock(&vcpu->kvm->mmu_lock);
+ read_unlock(&vcpu->kvm->mmu_lock);
if (kvm_pte_valid(pte))
kvm_set_pfn_accessed(kvm_pte_to_pfn(pte));
--
2.39.0.rc0.267.gcb52ba06e7-goog