On Fri, Jan 19, 2018 at 04:55:53PM +0100, Olivier Matz wrote:
> When using vector Rx mode (use_simple_rx = 1), vq->vq_descx[] is not
> kept up to date. To properly detach the mbufs in this case, browse
> sw_ring[] instead, as it's done in virtqueue_rxvq_flush().
>
> Since we need virtio_get_queue_type(), also move this function in
> virtqueue.h as a static inline.
>
> Fixes: fc3d66212fed ("virtio: add vector Rx")
> Cc: sta...@dpdk.org
>
> Signed-off-by: Olivier Matz <olivier.m...@6wind.com>
> ---
>
> Tiwei,
>
> While it passes my test plan, please carefully check that what I did in
> virtqueue_detatch_unused() is correct. I tried to reproduce what is done
> in virtqueue_rxvq_flush(), but I may be mistaking due to the different
> ring layout assumption and mbuf management between standard and vector.
>
> Thanks
> Olivier
>
>
> drivers/net/virtio/virtio_ethdev.c | 11 -----------
> drivers/net/virtio/virtqueue.c | 17 +++++++++++++++--
> drivers/net/virtio/virtqueue.h | 11 +++++++++++
> 3 files changed, 26 insertions(+), 13 deletions(-)
>
[...]
> struct rte_mbuf *
> virtqueue_detatch_unused(struct virtqueue *vq)
> {
> + struct virtio_hw *hw = vq->hw;
> struct rte_mbuf *cookie;
> int idx;
> + int type = virtio_get_queue_type(hw, vq->vq_queue_index);
> +
> + if (vq == NULL)
> + return NULL;
>
> - if (vq != NULL)
> - for (idx = 0; idx < vq->vq_nentries; idx++) {
> + for (idx = 0; idx < vq->vq_nentries; idx++) {
> + if (hw->use_simple_rx && type == VTNET_RQ) {
> + cookie = vq->sw_ring[idx];
> + if (cookie != NULL) {
> + vq->sw_ring[idx] = NULL;
Thanks for working on this!
The vq->sw_ring[idx] isn't zeroed during Rx. So besides the
check of (cookie != NULL), some other check is also needed
to avoid freeing the mbufs already delivered to application.
The mbufs in below interval belong to application:
start: sw_ring[vq->vq_avail_idx & (vq->vq_nentries - 1)] (included)
end: sw_ring[(vq->vq_avail_idx + vq->vq_free_cnt) & (vq->vq_nentries - 1)]
(excluded)
PS. (vq->vq_avail_idx & (vq->vq_nentries - 1)) can be greater than
(vq->vq_avail_idx + vq->vq_free_cnt) & (vq->vq_nentries - 1).
Thanks,
Tiwei
