KVM: irqchip: Provide and use accessors for irq routing table

This provides accessor functions for the KVM interrupt mappings, in
order to reduce the amount of code that accesses the fields of the
kvm_irq_routing_table struct, and restrict that code to one file,
virt/kvm/irqchip.c.  The new functions are kvm_irq_map_gsi(), which
maps from a global interrupt number to a set of IRQ routing entries,
and kvm_irq_map_chip_pin, which maps from IRQ chip and pin numbers to
a global interrupt number.

This also moves the update of kvm_irq_routing_table::chip[][]
into irqchip.c, out of the various kvm_set_routing_entry
implementations.  That means that none of the kvm_set_routing_entry
implementations need the kvm_irq_routing_table argument anymore,
so this removes it.

This does not change any locking or data lifetime rules.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Tested-by: Eric Auger <eric.auger@linaro.org>
Tested-by: Cornelia Huck <cornelia.huck@de.ibm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 9 insertions, 11 deletions

diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
index a228ee82bad2..175844593243 100644
--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -160,6 +160,7 @@ static int kvm_set_msi_inatomic(struct kvm_kernel_irq_routing_entry *e,
  */
 int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq, int level)
 {
+        struct kvm_kernel_irq_routing_entry entries[KVM_NR_IRQCHIPS];
         struct kvm_kernel_irq_routing_entry *e;
         int ret = -EINVAL;
         struct kvm_irq_routing_table *irq_rt;
@@ -177,14 +178,13 @@ int kvm_set_irq_inatomic(struct kvm *kvm, int irq_source_id, u32 irq, int level)
          */
         idx = srcu_read_lock(&kvm->irq_srcu);
         irq_rt = srcu_dereference(kvm->irq_routing, &kvm->irq_srcu);
-        if (irq < irq_rt->nr_rt_entries)
-                hlist_for_each_entry(e, &irq_rt->map[irq], link) {
-                        if (likely(e->type == KVM_IRQ_ROUTING_MSI))
-                                ret = kvm_set_msi_inatomic(e, kvm);
-                        else
-                                ret = -EWOULDBLOCK;
-                        break;
-                }
+        if (kvm_irq_map_gsi(entries, irq_rt, irq) > 0) {
+                e = &entries[0];
+                if (likely(e->type == KVM_IRQ_ROUTING_MSI))
+                        ret = kvm_set_msi_inatomic(e, kvm);
+                else
+                        ret = -EWOULDBLOCK;
+        }
         srcu_read_unlock(&kvm->irq_srcu, idx);
         return ret;
 }
@@ -272,8 +272,7 @@ void kvm_fire_mask_notifiers(struct kvm *kvm, unsigned irqchip, unsigned pin,
         srcu_read_unlock(&kvm->irq_srcu, idx);
 }
 
-int kvm_set_routing_entry(struct kvm_irq_routing_table *rt,
-                          struct kvm_kernel_irq_routing_entry *e,
+int kvm_set_routing_entry(struct kvm_kernel_irq_routing_entry *e,
                           const struct kvm_irq_routing_entry *ue)
 {
         int r = -EINVAL;
@@ -304,7 +303,6 @@ int kvm_set_routing_entry(struct kvm_irq_routing_table *rt,
                 e->irqchip.pin = ue->u.irqchip.pin + delta;
                 if (e->irqchip.pin >= max_pin)
                         goto out;
-                rt->chip[ue->u.irqchip.irqchip][e->irqchip.pin] = ue->gsi;
                 break;
         case KVM_IRQ_ROUTING_MSI:
                 e->set = kvm_set_msi;