[dpdk-dev] [PATCH v2 1/4] net/virtio: fix queue flushing with vector Rx enabled

[Olivier Matz]

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(-)

diff --git a/drivers/net/virtio/virtio_ethdev.c 
b/drivers/net/virtio/virtio_ethdev.c
index ec012c2ac..2c7f902e7 100644
--- a/drivers/net/virtio/virtio_ethdev.c
+++ b/drivers/net/virtio/virtio_ethdev.c
@@ -268,17 +268,6 @@ virtio_dev_queue_release(void *queue __rte_unused)
        /* do nothing */
 }
 
-static int
-virtio_get_queue_type(struct virtio_hw *hw, uint16_t vtpci_queue_idx)
-{
-       if (vtpci_queue_idx == hw->max_queue_pairs * 2)
-               return VTNET_CQ;
-       else if (vtpci_queue_idx % 2 == 0)
-               return VTNET_RQ;
-       else
-               return VTNET_TQ;
-}
-
 static uint16_t
 virtio_get_nr_vq(struct virtio_hw *hw)
 {
diff --git a/drivers/net/virtio/virtqueue.c b/drivers/net/virtio/virtqueue.c
index 1ada4fe08..43cb51d1b 100644
--- a/drivers/net/virtio/virtqueue.c
+++ b/drivers/net/virtio/virtqueue.c
@@ -18,17 +18,30 @@
 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;
+                               return cookie;
+                       }
+               } else {
                        cookie = vq->vq_descx[idx].cookie;
                        if (cookie != NULL) {
                                vq->vq_descx[idx].cookie = NULL;
                                return cookie;
                        }
                }
+       }
+
        return NULL;
 }
 
diff --git a/drivers/net/virtio/virtqueue.h b/drivers/net/virtio/virtqueue.h
index fedbaa39c..cae1b318a 100644
--- a/drivers/net/virtio/virtqueue.h
+++ b/drivers/net/virtio/virtqueue.h
@@ -281,6 +281,17 @@ virtqueue_full(const struct virtqueue *vq)
        return vq->vq_free_cnt == 0;
 }
 
+static inline int
+virtio_get_queue_type(struct virtio_hw *hw, uint16_t vtpci_queue_idx)
+{
+       if (vtpci_queue_idx == hw->max_queue_pairs * 2)
+               return VTNET_CQ;
+       else if (vtpci_queue_idx % 2 == 0)
+               return VTNET_RQ;
+       else
+               return VTNET_TQ;
+}
+
 #define VIRTQUEUE_NUSED(vq) ((uint16_t)((vq)->vq_ring.used->idx - 
(vq)->vq_used_cons_idx))
 
 void vq_ring_free_chain(struct virtqueue *vq, uint16_t desc_idx);
-- 
2.11.0