KVM: arm/arm64: Do not inject spurious interrupts

When lowering a level-triggered line from userspace, we forgot to lower
the pending bit on the emulated CPU interface and we also did not
re-compute the pending_on_cpu bitmap for the CPU affected by the change.

Update vgic_update_irq_pending() to fix the two issues above and also
raise a warning in vgic_quue_irq_to_lr if we encounter an interrupt
pending on a CPU which is neither marked active nor pending.

  [ Commit text reworked completely - Christoffer ]

Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c
index 6bd1c9bf7ae71504d042f455bce8ad9ca6abf6fc..596455a394af98d2b870b8f9326fb72844578256 100644 (file)
--- a/virt/kvm/arm/vgic.c
+++ b/virt/kvm/arm/vgic.c
@@ -1132,7 +1132,8 @@ static void vgic_queue_irq_to_lr(struct kvm_vcpu *vcpu, int irq,
                kvm_debug("Set active, clear distributor: 0x%x\n", vlr.state);
                vgic_irq_clear_active(vcpu, irq);
                vgic_update_state(vcpu->kvm);
-       } else if (vgic_dist_irq_is_pending(vcpu, irq)) {
+       } else {
+               WARN_ON(!vgic_dist_irq_is_pending(vcpu, irq));
                vlr.state |= LR_STATE_PENDING;
                kvm_debug("Set pending: 0x%x\n", vlr.state);
        }
@@ -1607,8 +1608,12 @@ static int vgic_update_irq_pending(struct kvm *kvm, int cpuid,
        } else {
                if (level_triggered) {
                        vgic_dist_irq_clear_level(vcpu, irq_num);
-                       if (!vgic_dist_irq_soft_pend(vcpu, irq_num))
+                       if (!vgic_dist_irq_soft_pend(vcpu, irq_num)) {
                                vgic_dist_irq_clear_pending(vcpu, irq_num);
+                               vgic_cpu_irq_clear(vcpu, irq_num);
+                               if (!compute_pending_for_cpu(vcpu))
+                                       clear_bit(cpuid, dist->irq_pending_on_cpu);
+                       }
                }
 
                ret = false;