irqbypass: Use paired consumer/producer to disconnect during unregister

Use the paired consumer/producer information to disconnect IRQ bypass
producers/consumers in O(1) time (ignoring the cost of __disconnect()).

Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Link: https://lore.kernel.org/r/20250516230734.2564775-6-seanjc@google.com
Signed-off-by: Sean Christopherson <seanjc@google.com>

diff --git a/virt/lib/irqbypass.c b/virt/lib/irqbypass.c
index fdbf7ecc0c21909d13c300c361d1178436e224dd..6a183459dc443ca58ca8354cd6ee5d4f5fe4c7e3 100644 (file)
--- a/virt/lib/irqbypass.c
+++ b/virt/lib/irqbypass.c
@@ -138,32 +138,16 @@ EXPORT_SYMBOL_GPL(irq_bypass_register_producer);
  */
 void irq_bypass_unregister_producer(struct irq_bypass_producer *producer)
 {
-       struct irq_bypass_producer *tmp;
-       struct irq_bypass_consumer *consumer;
-
        if (!producer->eventfd)
                return;
 
        mutex_lock(&lock);
 
-       list_for_each_entry(tmp, &producers, node) {
-               if (tmp->eventfd != producer->eventfd)
-                       continue;
-
-               list_for_each_entry(consumer, &consumers, node) {
-                       if (consumer->eventfd == producer->eventfd) {
-                               WARN_ON_ONCE(producer->consumer != consumer);
-                               __disconnect(producer, consumer);
-                               break;
-                       }
-               }
-
-               producer->eventfd = NULL;
-               list_del(&producer->node);
-               break;
-       }
+       if (producer->consumer)
+               __disconnect(producer, producer->consumer);
 
-       WARN_ON_ONCE(producer->eventfd);
+       producer->eventfd = NULL;
+       list_del(&producer->node);
        mutex_unlock(&lock);
 }
 EXPORT_SYMBOL_GPL(irq_bypass_unregister_producer);
@@ -228,32 +212,16 @@ EXPORT_SYMBOL_GPL(irq_bypass_register_consumer);
  */
 void irq_bypass_unregister_consumer(struct irq_bypass_consumer *consumer)
 {
-       struct irq_bypass_consumer *tmp;
-       struct irq_bypass_producer *producer;
-
        if (!consumer->eventfd)
                return;
 
        mutex_lock(&lock);
 
-       list_for_each_entry(tmp, &consumers, node) {
-               if (tmp != consumer)
-                       continue;
-
-               list_for_each_entry(producer, &producers, node) {
-                       if (producer->eventfd == consumer->eventfd) {
-                               WARN_ON_ONCE(consumer->producer != producer);
-                               __disconnect(producer, consumer);
-                               break;
-                       }
-               }
-
-               consumer->eventfd = NULL;
-               list_del(&consumer->node);
-               break;
-       }
+       if (consumer->producer)
+               __disconnect(consumer->producer, consumer);
 
-       WARN_ON_ONCE(consumer->eventfd);
+       consumer->eventfd = NULL;
+       list_del(&consumer->node);
        mutex_unlock(&lock);
 }
 EXPORT_SYMBOL_GPL(irq_bypass_unregister_consumer);