[PATCH 4/5] KVM: arm/arm64: vgic-v3: Do not use Active+Pending state for a HW interrupt

Marc Zyngier
2017-05-02T13:30:40Z

When an interrupt is injected with the HW bit set (indicating that
deactivation should be propagated to the physical distributor),
special care must be taken so that we never mark the corresponding
LR with the Active+Pending state (as the pending state is kept in
the physycal distributor).

Cc: stable@vger.kernel.org
Fixes: 59529f69f504 ("KVM: arm/arm64: vgic-new: Add GICv3 world switch backend")
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
virt/kvm/arm/vgic/vgic-v3.c | 7 +++++++
1 file changed, 7 insertions(+)

diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index df1503650300..393779ebe87c 100644
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -127,6 +127,13 @@ void vgic_v3_populate_lr(struct kvm_vcpu *vcpu, struct vgic_irq *irq, int lr)
if (irq->hw) {
val |= ICH_LR_HW;
val |= ((u64)irq->hwintid) << ICH_LR_PHYS_ID_SHIFT;
+ /*
+ * Never set pending+active on a HW interrupt, as the
+ * pending state is kept at the physical distributor
+ * level.
+ */
+ if (irq->active && irq_is_pending(irq))
+ val &= ~ICH_LR_PENDING_BIT;
} else {
if (irq->config == VGIC_CONFIG_LEVEL)
val |= ICH_LR_EOI;
--
2.11.0