[v2,1/2] KVM: export lockless GSI attribute

Commit Message

Gregory Haskins Oct. 23, 2009, 2:38 a.m. UTC

None

Patch

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index bd5a616..93393a4 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -119,6 +119,7 @@  struct kvm_memory_slot {
 struct kvm_kernel_irq_routing_entry {
 	u32 gsi;
 	u32 type;
+	bool lockless;
 	int (*set)(struct kvm_kernel_irq_routing_entry *e,
 		   struct kvm *kvm, int irq_source_id, int level);
 	union {
@@ -417,6 +418,7 @@  void kvm_get_intr_delivery_bitmask(struct kvm_ioapic *ioapic,
 				   unsigned long *deliver_bitmask);
 #endif
 int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level);
+int kvm_irq_check_lockless(struct kvm *kvm, u32 irq);
 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin);
 void kvm_register_irq_ack_notifier(struct kvm *kvm,
 				   struct kvm_irq_ack_notifier *kian);
diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
index 00c68d2..04f0134 100644
--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -174,6 +174,23 @@  int kvm_set_irq(struct kvm *kvm, int irq_source_id, u32 irq, int level)
 	return ret;
 }
 
+int kvm_irq_check_lockless(struct kvm *kvm, u32 irq)
+{
+	struct kvm_kernel_irq_routing_entry *e;
+	struct kvm_irq_routing_table *irq_rt;
+	struct hlist_node *n;
+	int ret = -ENOENT;
+
+	rcu_read_lock();
+	irq_rt = rcu_dereference(kvm->irq_routing);
+	if (irq < irq_rt->nr_rt_entries)
+		hlist_for_each_entry(e, n, &irq_rt->map[irq], link)
+			ret = e->lockless ? 1 : 0;
+	rcu_read_unlock();
+
+	return ret;
+}
+
 void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
 {
 	struct kvm_irq_ack_notifier *kian;
@@ -314,6 +331,7 @@  static int setup_routing_entry(struct kvm_irq_routing_table *rt,
 
 	e->gsi = ue->gsi;
 	e->type = ue->type;
+	e->lockless = false;
 	switch (ue->type) {
 	case KVM_IRQ_ROUTING_IRQCHIP:
 		delta = 0;
@@ -342,6 +360,7 @@  static int setup_routing_entry(struct kvm_irq_routing_table *rt,
 		e->msi.address_lo = ue->u.msi.address_lo;
 		e->msi.address_hi = ue->u.msi.address_hi;
 		e->msi.data = ue->u.msi.data;
+		e->lockless = true;
 		break;
 	default:
 		goto out;