KVM: arm64: GICv4.1: Restore VLPI pending state to physical side

When setting the forwarding path of a VLPI (switch to the HW mode),
we can also transfer the pending state from irq->pending_latch to
VPT (especially in migration, the pending states of VLPIs are restored
into kvm’s vgic first). And we currently send "INT+VSYNC" to trigger
a VLPI to pending.

Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Shenming Lu <lushenming@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20210322060158.1584-6-lushenming@huawei.com

diff --git a/arch/arm64/kvm/vgic/vgic-v4.c b/arch/arm64/kvm/vgic/vgic-v4.c
index ac029ba..c1845d8 100644 (file)
--- a/arch/arm64/kvm/vgic/vgic-v4.c
+++ b/arch/arm64/kvm/vgic/vgic-v4.c
@@ -404,6 +404,7 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
        struct vgic_its *its;
        struct vgic_irq *irq;
        struct its_vlpi_map map;
+       unsigned long flags;
        int ret;
 
        if (!vgic_supports_direct_msis(kvm))
@@ -449,6 +450,24 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
        irq->host_irq   = virq;
        atomic_inc(&map.vpe->vlpi_count);
 
+       /* Transfer pending state */
+       raw_spin_lock_irqsave(&irq->irq_lock, flags);
+       if (irq->pending_latch) {
+               ret = irq_set_irqchip_state(irq->host_irq,
+                                           IRQCHIP_STATE_PENDING,
+                                           irq->pending_latch);
+               WARN_RATELIMIT(ret, "IRQ %d", irq->host_irq);
+
+               /*
+                * Clear pending_latch and communicate this state
+                * change via vgic_queue_irq_unlock.
+                */
+               irq->pending_latch = false;
+               vgic_queue_irq_unlock(kvm, irq, flags);
+       } else {
+               raw_spin_unlock_irqrestore(&irq->irq_lock, flags);
+       }
+
 out:
        mutex_unlock(&its->its_lock);
        return ret;