KVM: arm/arm64: vgic-v3: Do not use Active+Pending state for a HW interrupt

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>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>

1 files changed, 7 insertions, 0 deletions

diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index 8fa737edde6f..6fe3f003636a 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;