On 2021-03-13 08:38, Shenming Lu wrote:
From: Zenghui Yu <yuzenghui@xxxxxxxxxx>
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@xxxxxxxxxx>
Signed-off-by: Shenming Lu <lushenming@xxxxxxxxxx>
---
arch/arm64/kvm/vgic/vgic-v4.c | 18 ++++++++++++++++++
1 file changed, 18 insertions(+)
diff --git a/arch/arm64/kvm/vgic/vgic-v4.c
b/arch/arm64/kvm/vgic/vgic-v4.c
index ac029ba3d337..3b82ab80c2f3 100644
--- a/arch/arm64/kvm/vgic/vgic-v4.c
+++ b/arch/arm64/kvm/vgic/vgic-v4.c
@@ -449,6 +449,24 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm,
int virq,
irq->host_irq = virq;
atomic_inc(&map.vpe->vlpi_count);
+ /* Transfer pending state */
+ if (irq->pending_latch) {
+ unsigned long flags;
+
+ 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.
+ */
+ raw_spin_lock_irqsave(&irq->irq_lock, flags);
+ irq->pending_latch = false;
+ vgic_queue_irq_unlock(kvm, irq, flags);
+ }
+
out:
mutex_unlock(&its->its_lock);
return ret;
The read side of the pending state isn't locked, but the write side is.
I'd rather you lock the whole sequence for peace of mind.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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