diff options
Diffstat (limited to 'Documentation/lguest/lguest.c')
| -rw-r--r-- | Documentation/lguest/lguest.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c index 84c471b07c27..20f8253881b3 100644 --- a/Documentation/lguest/lguest.c +++ b/Documentation/lguest/lguest.c @@ -151,6 +151,9 @@ struct virtqueue /* Last available index we saw. */ u16 last_avail_idx; + /* How many are used since we sent last irq? */ + unsigned int pending_used; + /* Eventfd where Guest notifications arrive. */ int eventfd; @@ -556,6 +559,11 @@ static void trigger_irq(struct virtqueue *vq) { unsigned long buf[] = { LHREQ_IRQ, vq->config.irq }; + /* Don't inform them if nothing used. */ + if (!vq->pending_used) + return; + vq->pending_used = 0; + /* If they don't want an interrupt, don't send one, unless empty. */ if ((vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT) && lg_last_avail(vq) != vq->vring.avail->idx) @@ -647,6 +655,7 @@ static void add_used(struct virtqueue *vq, unsigned int head, int len) /* Make sure buffer is written before we update index. */ wmb(); vq->vring.used->idx++; + vq->pending_used++; } /* And here's the combo meal deal. Supersize me! */ |