[PATCH 5/6] KVM: arm64: Couple VNCR fixmap clearing and CPU number invalidation

[Marc Zyngier <maz@kernel.org>]

A mapped VNCR translation must indicate which CPU it is resident.
Unmapping such a translation must make this CPU number -1.

Couple the unmap and the setting to -1 in a helper, so that we
are always sure they are done together.

Signed-off-by: Marc Zyngier <maz@kernel.org>
---
 arch/arm64/kvm/nested.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/arch/arm64/kvm/nested.c b/arch/arm64/kvm/nested.c
index 47d61d3cf053c..84915e2cff604 100644
--- a/arch/arm64/kvm/nested.c
+++ b/arch/arm64/kvm/nested.c
@@ -894,6 +894,12 @@ void kvm_vcpu_load_hw_mmu(struct kvm_vcpu *vcpu)
 	}
 }
 
+static void unmap_l1_vncr(struct vncr_tlb *vt)
+{
+	clear_fixmap(vncr_fixmap(vt->cpu));
+	vt->cpu = -1;
+}
+
 static void this_cpu_reset_vncr_fixmap(struct kvm_vcpu *vcpu)
 {
 	if (!host_data_test_flag(L1_VNCR_MAPPED))
@@ -902,8 +908,7 @@ static void this_cpu_reset_vncr_fixmap(struct kvm_vcpu *vcpu)
 	BUG_ON(vcpu->arch.vncr_tlb->cpu != smp_processor_id());
 	BUG_ON(is_hyp_ctxt(vcpu));
 
-	clear_fixmap(vncr_fixmap(vcpu->arch.vncr_tlb->cpu));
-	vcpu->arch.vncr_tlb->cpu = -1;
+	unmap_l1_vncr(vcpu->arch.vncr_tlb);
 	host_data_clear_flag(L1_VNCR_MAPPED);
 }
 
@@ -996,7 +1001,7 @@ static void invalidate_vncr(struct vncr_tlb *vt)
 {
 	vt->valid = false;
 	if (vt->cpu != -1)
-		clear_fixmap(vncr_fixmap(vt->cpu));
+		unmap_l1_vncr(vt);
 }
 
 static bool vncr_tlb_intersects(struct vncr_tlb *vt, u64 addr,
-- 
2.47.3