From b6a114d27273c37cd0107b0f49af208168498f05 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Wed, 13 Jan 2010 19:12:30 +0200 Subject: [PATCH] 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 Signed-off-by: Avi Kivity --- virt/kvm/eventfd.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/virt/kvm/eventfd.c b/virt/kvm/eventfd.c index 62e4cd947a90..a9d3fc6c681c 100644 --- a/virt/kvm/eventfd.c +++ b/virt/kvm/eventfd.c @@ -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 -- GitLab