[dpdk-stable] [PATCH] vdpa/mlx5: fix virtq unset

[Matan Azrad]

When a virtq is destroyed, the SW should be able to continue the virtq
processing from where the HW stopped.

The current destroy behavior in the driver saves the virtq state (used
and available indexes) only when LM is requested.
So, when LM is not requested the queue state is not saved and the SW
indexes stay invalid.

Save the virtq state in the virtq destroy process.

Fixes: bff735011078 ("vdpa/mlx5: prepare virtio queues")
Cc: stable at dpdk.org

Signed-off-by: Matan Azrad <matan at mellanox.com>
Acked-by: Xueming Li <xuemingl at mellanox.com>
---
 drivers/vdpa/mlx5/mlx5_vdpa.h       |  1 +
 drivers/vdpa/mlx5/mlx5_vdpa_virtq.c | 17 ++++++++++++-----
 2 files changed, 13 insertions(+), 5 deletions(-)

diff --git a/drivers/vdpa/mlx5/mlx5_vdpa.h b/drivers/vdpa/mlx5/mlx5_vdpa.h
index 57044d9..5963e35 100644
--- a/drivers/vdpa/mlx5/mlx5_vdpa.h
+++ b/drivers/vdpa/mlx5/mlx5_vdpa.h
@@ -86,6 +86,7 @@ struct mlx5_vdpa_virtq {
 	uint16_t index;
 	uint16_t vq_size;
 	uint8_t notifier_state;
+	bool stopped;
 	struct mlx5_vdpa_priv *priv;
 	struct mlx5_devx_obj *virtq;
 	struct mlx5_devx_obj *counters;
diff --git a/drivers/vdpa/mlx5/mlx5_vdpa_virtq.c b/drivers/vdpa/mlx5/mlx5_vdpa_virtq.c
index 19554f6..17e71cf 100644
--- a/drivers/vdpa/mlx5/mlx5_vdpa_virtq.c
+++ b/drivers/vdpa/mlx5/mlx5_vdpa_virtq.c
@@ -72,8 +72,13 @@
 		}
 		virtq->intr_handle.fd = -1;
 	}
-	if (virtq->virtq)
+	if (virtq->virtq) {
+		ret = mlx5_vdpa_virtq_stop(virtq->priv, virtq->index);
+		if (ret)
+			DRV_LOG(WARNING, "Failed to stop virtq %d.",
+				virtq->index);
 		claim_zero(mlx5_devx_cmd_destroy(virtq->virtq));
+	}
 	virtq->virtq = NULL;
 	for (i = 0; i < RTE_DIM(virtq->umems); ++i) {
 		if (virtq->umems[i].obj)
@@ -135,10 +140,14 @@
 {
 	struct mlx5_devx_virtq_attr attr = {0};
 	struct mlx5_vdpa_virtq *virtq = &priv->virtqs[index];
-	int ret = mlx5_vdpa_virtq_modify(virtq, 0);
+	int ret;
 
+	if (virtq->stopped)
+		return 0;
+	ret = mlx5_vdpa_virtq_modify(virtq, 0);
 	if (ret)
 		return -1;
+	virtq->stopped = true;
 	if (mlx5_devx_cmd_query_virtq(virtq->virtq, &attr)) {
 		DRV_LOG(ERR, "Failed to query virtq %d.", index);
 		return -1;
@@ -323,6 +332,7 @@
 				virtq->intr_handle.fd, index);
 		}
 	}
+	virtq->stopped = false;
 	DRV_LOG(DEBUG, "vid %u virtq %u was created successfully.", priv->vid,
 		index);
 	return 0;
@@ -489,9 +499,6 @@
 				DRV_LOG(WARNING, "Failed to disable steering "
 					"for virtq %d.", index);
 		}
-		ret = mlx5_vdpa_virtq_stop(priv, index);
-		if (ret)
-			DRV_LOG(WARNING, "Failed to stop virtq %d.", index);
 		mlx5_vdpa_virtq_unset(virtq);
 	}
 	if (enable) {
-- 
1.8.3.1