[PATCH] vdpa/mlx5: fix queue enable drain CQ

[Yajun Wu]

For the case: `ethtool -L eth0 combined xxx` in VM, VQ will disable
and enable without calling device close. In such case, need add
drain CQ before reuse/reset event QP.

Fixes: 24969c7b62 ("vdpa/mlx5: reuse event queues")
Cc: sta...@dpdk.org

Signed-off-by: Yajun Wu <yaj...@nvidia.com>
Acked-by: Matan Azrad <ma...@nvidia.com>
---
 drivers/vdpa/mlx5/mlx5_vdpa_event.c | 29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)

diff --git a/drivers/vdpa/mlx5/mlx5_vdpa_event.c 
b/drivers/vdpa/mlx5/mlx5_vdpa_event.c
index 9557c1042e..32430614d5 100644
--- a/drivers/vdpa/mlx5/mlx5_vdpa_event.c
+++ b/drivers/vdpa/mlx5/mlx5_vdpa_event.c
@@ -244,22 +244,30 @@ mlx5_vdpa_queues_complete(struct mlx5_vdpa_priv *priv)
        return max;
 }
 
+static void
+mlx5_vdpa_drain_cq_one(struct mlx5_vdpa_priv *priv,
+       struct mlx5_vdpa_virtq *virtq)
+{
+       struct mlx5_vdpa_cq *cq = &virtq->eqp.cq;
+
+       mlx5_vdpa_queue_complete(cq);
+       if (cq->cq_obj.cq) {
+               cq->cq_obj.cqes[0].wqe_counter = rte_cpu_to_be_16(UINT16_MAX);
+               virtq->eqp.qp_pi = 0;
+               if (!cq->armed)
+                       mlx5_vdpa_cq_arm(priv, cq);
+       }
+}
+
 void
 mlx5_vdpa_drain_cq(struct mlx5_vdpa_priv *priv)
 {
+       struct mlx5_vdpa_virtq *virtq;
        unsigned int i;
 
        for (i = 0; i < priv->caps.max_num_virtio_queues; i++) {
-               struct mlx5_vdpa_cq *cq = &priv->virtqs[i].eqp.cq;
-
-               mlx5_vdpa_queue_complete(cq);
-               if (cq->cq_obj.cq) {
-                       cq->cq_obj.cqes[0].wqe_counter =
-                               rte_cpu_to_be_16(UINT16_MAX);
-                       priv->virtqs[i].eqp.qp_pi = 0;
-                       if (!cq->armed)
-                               mlx5_vdpa_cq_arm(priv, cq);
-               }
+               virtq = &priv->virtqs[i];
+               mlx5_vdpa_drain_cq_one(priv, virtq);
        }
 }
 
@@ -632,6 +640,7 @@ mlx5_vdpa_event_qp_prepare(struct mlx5_vdpa_priv *priv, 
uint16_t desc_n,
        if (eqp->cq.cq_obj.cq != NULL && log_desc_n == eqp->cq.log_desc_n) {
                /* Reuse existing resources. */
                eqp->cq.callfd = callfd;
+               mlx5_vdpa_drain_cq_one(priv, virtq);
                /* FW will set event qp to error state in q destroy. */
                if (reset && !mlx5_vdpa_qps2rst2rts(eqp))
                        rte_write32(rte_cpu_to_be_32(RTE_BIT32(log_desc_n)),
-- 
2.27.0