KVM: arm64: vgic-v3: Indicate vgic_put_irq() may take LPI xarray lock

The release path on LPIs is quite rare, meaning it can be difficult to
find lock ordering bugs on the LPI xarray's spinlock. Tell lockdep that
vgic_put_irq() might acquire the xa_lock to make unsafe patterns more
obvious.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250905100531.282980-7-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>

diff --git a/arch/arm64/kvm/vgic/vgic.c b/arch/arm64/kvm/vgic/vgic.c
index a21b482844ce845ab91413a4d146e91b7f63c1d1..3b247041a1300c842a109da4ecec3f398c2cc459 100644 (file)
--- a/arch/arm64/kvm/vgic/vgic.c
+++ b/arch/arm64/kvm/vgic/vgic.c
@@ -142,6 +142,9 @@ void vgic_put_irq(struct kvm *kvm, struct vgic_irq *irq)
 {
        struct vgic_dist *dist = &kvm->arch.vgic;
 
+       if (irq->intid >= VGIC_MIN_LPI)
+               might_lock(&dist->lpi_xa.xa_lock);
+
        if (!__vgic_put_irq(kvm, irq))
                return;