KVM: fix spurious interrupt with irqfd

kvm didn't clear irqfd counter on deassign, as a result we could get a
spurious interrupt when irqfd is assigned back. this leads to poor
performance and, in theory, guest crash.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
This commit is contained in:
Michael S. Tsirkin 2010-01-13 19:12:30 +02:00 committed by Marcelo Tosatti
parent cb289d6244
commit b6a114d272
1 changed files with 2 additions and 1 deletions

View File

@ -72,12 +72,13 @@ static void
irqfd_shutdown(struct work_struct *work)
{
struct _irqfd *irqfd = container_of(work, struct _irqfd, shutdown);
u64 cnt;
/*
* Synchronize with the wait-queue and unhook ourselves to prevent
* further events.
*/
remove_wait_queue(irqfd->wqh, &irqfd->wait);
eventfd_ctx_remove_wait_queue(irqfd->eventfd, &irqfd->wait, &cnt);
/*
* We know no new events will be scheduled at this point, so block