On 2021-01-04 08:16, Shenming Lu wrote:
From: Zenghui Yu <yuzenghui@xxxxxxxxxx>
When setting the forwarding path of a VLPI (switch to the HW mode),
we could 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@xxxxxxxxxx>
Signed-off-by: Shenming Lu <lushenming@xxxxxxxxxx>
---
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 f211a7c32704..7945d6d09cdd 100644
--- a/arch/arm64/kvm/vgic/vgic-v4.c
+++ b/arch/arm64/kvm/vgic/vgic-v4.c
@@ -454,6 +454,18 @@ 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);
Why do this if pending_latch is 0, which is likely to be
the overwhelming case?
+
+ /*
+ * Let it be pruned from ap_list later and don't bother
+ * the List Register.
+ */
+ irq->pending_latch = false;
What guarantees the pruning? Pruning only happens on vcpu exit,
which means we may have the same interrupt via both the LR and
the stream interface, which I don't believe is legal (it is
like having two LRs holding the same interrupt).
+
out:
mutex_unlock(&its->its_lock);
return ret;
Thanks,
M.
--
Jazz is not dead. It just smells funny...
