virtio: handle interrupts after callbacks turned off

[safe/jmp/linux-2.6] / drivers / virtio / virtio_ring.c

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index dbe1d35..9859213 100644 (file)
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -173,16 +173,6 @@ static void detach_buf(struct vring_virtqueue *vq, unsigned int head)
        vq->num_free++;
 }
 
-/* FIXME: We need to tell other side about removal, to synchronize. */
-static void vring_shutdown(struct virtqueue *_vq)
-{
-       struct vring_virtqueue *vq = to_vvq(_vq);
-       unsigned int i;
-
-       for (i = 0; i < vq->vring.num; i++)
-               detach_buf(vq, i);
-}
-
 static inline bool more_used(const struct vring_virtqueue *vq)
 {
        return vq->last_used_idx != vq->vring.used->idx;
@@ -265,6 +255,13 @@ irqreturn_t vring_interrupt(int irq, void *_vq)
        if (unlikely(vq->broken))
                return IRQ_HANDLED;
 
+       /* Other side may have missed us turning off the interrupt,
+        * but we should preserve disable semantic for virtio users. */
+       if (unlikely(vq->vring.avail->flags & VRING_AVAIL_F_NO_INTERRUPT)) {
+               pr_debug("virtqueue interrupt after disable for %p\n", vq);
+               return IRQ_HANDLED;
+       }
+
        pr_debug("virtqueue callback for %p (%p)\n", vq, vq->vq.callback);
        if (vq->vq.callback)
                vq->vq.callback(&vq->vq);
@@ -278,7 +275,6 @@ static struct virtqueue_ops vring_vq_ops = {
        .kick = vring_kick,
        .disable_cb = vring_disable_cb,
        .enable_cb = vring_enable_cb,
-       .shutdown = vring_shutdown,
 };
 
 struct virtqueue *vring_new_virtqueue(unsigned int num,