On Thu, May 26, 2022 at 09:34:01PM -0400, Bo Liu wrote:
> virtqueue_add_outbuf() can fail, when it fails, there is no need
> to call the funciont virtqueue_kick().
> Signed-off-by: Bo Liu <liubo03@xxxxxxxxxx>
Sorry don't get it.
What's the point of this patch really?
> ---
> drivers/virtio/virtio_balloon.c | 18 +++++++++++-------
> 1 file changed, 11 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/virtio/virtio_balloon.c b/drivers/virtio/virtio_balloon.c
> index b9737da6c4dd..0d7da4d95e1e 100644
> --- a/drivers/virtio/virtio_balloon.c
> +++ b/drivers/virtio/virtio_balloon.c
> @@ -153,16 +153,18 @@ static void tell_host(struct virtio_balloon *vb, struct virtqueue *vq)
> {
> struct scatterlist sg;
> unsigned int len;
> + int err;
>
> sg_init_one(&sg, vb->pfns, sizeof(vb->pfns[0]) * vb->num_pfns);
>
> /* We should always be able to add one buffer to an empty queue. */
> - virtqueue_add_outbuf(vq, &sg, 1, vb, GFP_KERNEL);
> - virtqueue_kick(vq);
> -
> - /* When host has read buffer, this completes via balloon_ack */
> - wait_event(vb->acked, virtqueue_get_buf(vq, &len));
> + err = virtqueue_add_outbuf(vq, &sg, 1, vb, GFP_KERNEL);
> + if (!err) {
> + virtqueue_kick(vq);
>
> + /* When host has read buffer, this completes via balloon_ack */
> + wait_event(vb->acked, virtqueue_get_buf(vq, &len));
> + }
> }
>
> static int virtballoon_free_page_report(struct page_reporting_dev_info *pr_dev_info,
> @@ -382,6 +384,7 @@ static void stats_handle_request(struct virtio_balloon *vb)
> struct virtqueue *vq;
> struct scatterlist sg;
> unsigned int len, num_stats;
> + int err;
>
> num_stats = update_balloon_stats(vb);
>
> @@ -389,8 +392,9 @@ static void stats_handle_request(struct virtio_balloon *vb)
> if (!virtqueue_get_buf(vq, &len))
> return;
> sg_init_one(&sg, vb->stats, sizeof(vb->stats[0]) * num_stats);
> - virtqueue_add_outbuf(vq, &sg, 1, vb, GFP_KERNEL);
> - virtqueue_kick(vq);
> + err = virtqueue_add_outbuf(vq, &sg, 1, vb, GFP_KERNEL);
> + if (!err)
> + virtqueue_kick(vq);
> }
>
> static inline s64 towards_target(struct virtio_balloon *vb)
> --
> 2.27.0
_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
