kvm/eventfd: Drain events from eventfd in irqfd_wakeup()

Don't allow the events to accumulate in the eventfd counter, drain them as they are handled. Signed-off-by: David Woodhouse <[email protected]> Message-Id: <[email protected]> Signed-off-by: Paolo Bonzini <[email protected]>
LoveHeat · Nov 15, 2020 · b59e00d · b59e00d
1 parent b1b397a
commit b59e00d
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c
@@ -194,6 +194,9 @@ irqfd_wakeup(wait_queue_entry_t *wait, unsigned mode, int sync, void *key)
 	int ret = 0;
 
 	if (flags & EPOLLIN) {
+		u64 cnt;
+		eventfd_ctx_do_read(irqfd->eventfd, &cnt);
+
 		idx = srcu_read_lock(&kvm->irq_srcu);
 		do {
 			seq = read_seqcount_begin(&irqfd->irq_entry_sc);