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kernel os linux

KVM: arm/arm64: vgic-v3: Always resample level interrupts

When reading back from the list registers, we need to perform
two actions for level interrupts:
1) clear the soft-pending bit if the interrupt is not pending
anymore *in the list register*
2) resample the line level and propagate it to the pending state

But these two actions shouldn't be linked, and we should *always*
resample the line level, no matter what state is in the list
register. Otherwise, we may end-up injecting spurious interrupts
that have been already retired.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

authored by

Marc Zyngier and committed by
Christoffer Dall
637d122b df7942d1

+9 -5
+9 -5
virt/kvm/arm/vgic/vgic-v3.c
··· 101 101 } 102 102 } 103 103 104 - /* Clear soft pending state when level irqs have been acked */ 105 - if (irq->config == VGIC_CONFIG_LEVEL && 106 - !(val & ICH_LR_PENDING_BIT)) { 107 - irq->soft_pending = false; 108 - irq->pending = irq->line_level; 104 + /* 105 + * Clear soft pending state when level irqs have been acked. 106 + * Always regenerate the pending state. 107 + */ 108 + if (irq->config == VGIC_CONFIG_LEVEL) { 109 + if (!(val & ICH_LR_PENDING_BIT)) 110 + irq->soft_pending = false; 111 + 112 + irq->pending = irq->line_level || irq->soft_pending; 109 113 } 110 114 111 115 spin_unlock(&irq->irq_lock);