linux-kernel - [PATCH 5.5 085/120] KVM: arm/arm64: Fix young bit from mmu notifier

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Date:   Thu, 13 Feb 2020 07:21:21 -0800
From:   Greg Kroah-Hartman <gregkh@...uxfoundation.org>
To:     linux-kernel@...r.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        stable@...r.kernel.org, Gavin Shan <gshan@...hat.com>,
        Marc Zyngier <maz@...nel.org>
Subject: [PATCH 5.5 085/120] KVM: arm/arm64: Fix young bit from mmu notifier

From: Gavin Shan <gshan@...hat.com>

commit cf2d23e0bac9f6b5cd1cba8898f5f05ead40e530 upstream.

kvm_test_age_hva() is called upon mmu_notifier_test_young(), but wrong
address range has been passed to handle_hva_to_gpa(). With the wrong
address range, no young bits will be checked in handle_hva_to_gpa().
It means zero is always returned from mmu_notifier_test_young().

This fixes the issue by passing correct address range to the underly
function handle_hva_to_gpa(), so that the hardware young (access) bit
will be visited.

Fixes: 35307b9a5f7e ("arm/arm64: KVM: Implement Stage-2 page aging")
Signed-off-by: Gavin Shan <gshan@...hat.com>
Signed-off-by: Marc Zyngier <maz@...nel.org>
Link: https://lore.kernel.org/r/20200121055659.19560-1-gshan@redhat.com
Signed-off-by: Greg Kroah-Hartman <gregkh@...uxfoundation.org>

---
 virt/kvm/arm/mmu.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

--- a/virt/kvm/arm/mmu.c
+++ b/virt/kvm/arm/mmu.c
@@ -2147,7 +2147,8 @@ int kvm_test_age_hva(struct kvm *kvm, un
 	if (!kvm->arch.pgd)
 		return 0;
 	trace_kvm_test_age_hva(hva);
-	return handle_hva_to_gpa(kvm, hva, hva, kvm_test_age_hva_handler, NULL);
+	return handle_hva_to_gpa(kvm, hva, hva + PAGE_SIZE,
+				 kvm_test_age_hva_handler, NULL);
 }
 
 void kvm_mmu_free_memory_caches(struct kvm_vcpu *vcpu)