[PATCH 4.16 016/110] KVM: arm/arm64: VGIC/ITS: Promote irq_lock() in update_affinity

[Greg Kroah-Hartman]

4.16-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andre Przywara <andre.przywara@xxxxxxx>

commit 9c4188762f7fee032abf8451fd9865a9abfc5516 upstream.

Apparently the development of update_affinity() overlapped with the
promotion of irq_lock to be _irqsave, so the patch didn't convert this
lock over. This will make lockdep complain.

Fix this by disabling IRQs around the lock.

Cc: stable@xxxxxxxxxxxxxxx
Fixes: 08c9fd042117 ("KVM: arm/arm64: vITS: Add a helper to update the affinity of an LPI")
Reported-by: Jan Glauber <jan.glauber@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andre Przywara <andre.przywara@xxxxxxx>
Acked-by: Christoffer Dall <christoffer.dall@xxxxxxx>
Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 virt/kvm/arm/vgic/vgic-its.c |    5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -350,10 +350,11 @@ static int vgic_copy_lpi_list(struct kvm
 static int update_affinity(struct vgic_irq *irq, struct kvm_vcpu *vcpu)
 {
 	int ret = 0;
+	unsigned long flags;
 
-	spin_lock(&irq->irq_lock);
+	spin_lock_irqsave(&irq->irq_lock, flags);
 	irq->target_vcpu = vcpu;
-	spin_unlock(&irq->irq_lock);
+	spin_unlock_irqrestore(&irq->irq_lock, flags);
 
 	if (irq->hw) {
 		struct its_vlpi_map map;