[PATCH v3] KVM: arm64: GICv4: Do not perform a map to a mapped vLPI

[Kunkun Jiang]

Before performing a map, let's check whether the vLPI has been
mapped.

Fixes: 196b136498b3 ("KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass")
Signed-off-by: Kunkun Jiang <jiangkunkun at huawei.com>
Acked-by: Marc Zyngier <maz at kernel.org>
---
 arch/arm64/kvm/vgic/vgic-v4.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm64/kvm/vgic/vgic-v4.c b/arch/arm64/kvm/vgic/vgic-v4.c
index 339a55194b2c..74a67ad87f29 100644
--- a/arch/arm64/kvm/vgic/vgic-v4.c
+++ b/arch/arm64/kvm/vgic/vgic-v4.c
@@ -436,6 +436,10 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
 	if (ret)
 		goto out;
 
+	/* Silently exit if the vLPI is already mapped */
+	if (irq->hw)
+		goto out;
+
 	/*
 	 * Emit the mapping request. If it fails, the ITS probably
 	 * isn't v4 compatible, so let's silently bail out. Holding
-- 
2.33.0