[RFC PATCH v1 3/4] KVM: arm64: GICv4.1: Restore VLPI's pending state to physical side

Shenming Lu
2020-11-23T06:55:13Z

From: Zenghui Yu <yuzenghui@huawei.com>

When setting the forwarding path of a VLPI, it is more consistent to
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>
---
arch/arm64/kvm/vgic/vgic-v4.c | 12 ++++++++++++
1 file changed, 12 insertions(+)

diff --git a/arch/arm64/kvm/vgic/vgic-v4.c b/arch/arm64/kvm/vgic/vgic-v4.c
index b5fa73c9fd35..cc3ab9cea182 100644
--- a/arch/arm64/kvm/vgic/vgic-v4.c
+++ b/arch/arm64/kvm/vgic/vgic-v4.c
@@ -418,6 +418,18 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq,
irq->host_irq = virq;
atomic_inc(&map.vpe->vlpi_count);

+ /* Transfer pending state */
+ ret = irq_set_irqchip_state(irq->host_irq,
+ IRQCHIP_STATE_PENDING,
+ irq->pending_latch);
+ WARN_RATELIMIT(ret, "IRQ %d", irq->host_irq);
+
+ /*
+ * Let it be pruned from ap_list later and don't bother
+ * the List Register.
+ */
+ irq->pending_latch = false;
+
out:
mutex_unlock(&its->its_lock);
return ret;
--
2.23.0