1 files changed, 85 insertions, 0 deletions
diff --git a/virt/kvm/irqchip.c b/virt/kvm/irqchip.c
index 12f7f26af4f8..20dc9e4a8f6c 100644
--- a/virt/kvm/irqchip.c
+++ b/virt/kvm/irqchip.c
@@ -150,3 +150,88 @@ void kvm_free_irq_routing(struct kvm *kvm)
 	   at this stage */
 	kfree(kvm->irq_routing);
 }
+
+static int setup_routing_entry(struct kvm_irq_routing_table *rt,
+			       struct kvm_kernel_irq_routing_entry *e,
+			       const struct kvm_irq_routing_entry *ue)
+{
+	int r = -EINVAL;
+	struct kvm_kernel_irq_routing_entry *ei;
+
+	/*
+	 * Do not allow GSI to be mapped to the same irqchip more than once.
+	 * Allow only one to one mapping between GSI and MSI.
+	 */
+	hlist_for_each_entry(ei, &rt->map[ue->gsi], link)
+		if (ei->type == KVM_IRQ_ROUTING_MSI ||
+		    ue->type == KVM_IRQ_ROUTING_MSI ||
+		    ue->u.irqchip.irqchip == ei->irqchip.irqchip)
+			return r;
+
+	e->gsi = ue->gsi;
+	e->type = ue->type;
+	r = kvm_set_routing_entry(rt, e, ue);
+	if (r)
+		goto out;
+
+	hlist_add_head(&e->link, &rt->map[e->gsi]);
+	r = 0;
+out:
+	return r;
+}
+
+int kvm_set_irq_routing(struct kvm *kvm,
+			const struct kvm_irq_routing_entry *ue,
+			unsigned nr,
+			unsigned flags)
+{
+	struct kvm_irq_routing_table *new, *old;
+	u32 i, j, nr_rt_entries = 0;
+	int r;
+
+	for (i = 0; i < nr; ++i) {
+		if (ue[i].gsi >= KVM_MAX_IRQ_ROUTES)
+			return -EINVAL;
+		nr_rt_entries = max(nr_rt_entries, ue[i].gsi);
+	}
+
+	nr_rt_entries += 1;
+
+	new = kzalloc(sizeof(*new) + (nr_rt_entries * sizeof(struct hlist_head))
+		      + (nr * sizeof(struct kvm_kernel_irq_routing_entry)),
+		      GFP_KERNEL);
+
+	if (!new)
+		return -ENOMEM;
+
+	new->rt_entries = (void *)&new->map[nr_rt_entries];
+
+	new->nr_rt_entries = nr_rt_entries;
+	for (i = 0; i < KVM_NR_IRQCHIPS; i++)
+		for (j = 0; j < KVM_IRQCHIP_NUM_PINS; j++)
+			new->chip[i][j] = -1;
+
+	for (i = 0; i < nr; ++i) {
+		r = -EINVAL;
+		if (ue->flags)
+			goto out;
+		r = setup_routing_entry(new, &new->rt_entries[i], ue);
+		if (r)
+			goto out;
+		++ue;
+	}
+
+	mutex_lock(&kvm->irq_lock);
+	old = kvm->irq_routing;
+	kvm_irq_routing_update(kvm, new);
+	mutex_unlock(&kvm->irq_lock);
+
+	synchronize_rcu();
+
+	new = old;
+	r = 0;
+
+out:
+	kfree(new);
+	return r;
+}