[PATCH v2 48/52] KVM: arm/arm64: GICv4: Add doorbell interrupt handling

[Marc Zyngier]

When a vPE is not running, the delivery of a VLPI results in a
doorbell interrupt to be delivered. Let's handle this interrupt
and update the pending_last flag that indicates that VLPIs are
pending.

Signed-off-by: Marc Zyngier <marc.zyng...@arm.com>
---
 virt/kvm/arm/vgic/vgic-v4.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c
index a2d1a6db0490..fe0d0a8ed469 100644
--- a/virt/kvm/arm/vgic/vgic-v4.c
+++ b/virt/kvm/arm/vgic/vgic-v4.c
@@ -21,6 +21,14 @@
 
 #include "vgic.h"
 
+static irqreturn_t vgic_v4_doorbell_handler(int irq, void *info)
+{
+       struct kvm_vcpu *vcpu = info;
+
+       vcpu->arch.vgic_cpu.vgic_v3.its_vpe.pending_last = true;
+       return IRQ_HANDLED;
+}
+
 int vgic_v4_init(struct kvm *kvm)
 {
        struct vgic_dist *dist = &kvm->arch.vgic;
@@ -47,12 +55,34 @@ int vgic_v4_init(struct kvm *kvm)
                return ret;
        }
 
+       kvm_for_each_vcpu(i, vcpu, kvm) {
+               int irq = dist->its_vm.vpes[i]->irq;
+
+               ret = request_irq(irq, vgic_v4_doorbell_handler,
+                                 0, "vcpu", vcpu);
+               if (ret) {
+                       kvm_err("failed to allocate vcpu IRQ%d\n", irq);
+                       dist->its_vm.nr_vpes = i;
+                       break;
+               }
+       }
+
+       if (ret)
+               vgic_v4_teardown(kvm);
+
        return ret;
 }
 
 void vgic_v4_teardown(struct kvm *kvm)
 {
        struct its_vm *its_vm = &kvm->arch.vgic.its_vm;
+       struct kvm_vcpu *vcpu;
+       int i;
+
+       for (i = 0; i < its_vm->nr_vpes; i++) {
+               vcpu = kvm_get_vcpu(kvm, i);
+               free_irq(its_vm->vpes[i]->irq, vcpu);
+       }
 
        its_free_vcpu_irqs(its_vm);
        kfree(its_vm->vpes);
-- 
2.11.0