diff mbox series

[v1,2/2] vdpa/mlx5: retry VAR allocation during vDPA restart

Message ID 20211015134319.1664761-2-xuemingl@nvidia.com (mailing list archive)
State Superseded, archived
Delegated to: Maxime Coquelin
Headers
Series [v1,1/2] vdpa/mlx5: workaround FW first completion in start |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/github-robot: build success github build: passed
ci/Intel-compilation success Compilation OK
ci/intel-Testing success Testing PASS

Commit Message

Xueming Li Oct. 15, 2021, 1:43 p.m. UTC 
  VAR is the device memory space for the virtio queues doorbells, qemu
could mmap it to directly to speed up doorbell push.

On a busy system, Qemu takes time to release VAR resources during driver
shutdown. If vdpa restarted quickly, the VAR allocation failed with
error 28 since the VAR is singleton resource per device.

This patch adds retry mechanism for VAR allocation.

Cc: stable@dpdk.org

Signed-off-by: Xueming Li <xuemingl@nvidia.com>
Reviewed-by: Matan Azrad <matan@nvidia.com>
---
 drivers/vdpa/mlx5/mlx5_vdpa.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/drivers/vdpa/mlx5/mlx5_vdpa.c b/drivers/vdpa/mlx5/mlx5_vdpa.c
index 6d17d7a6f3e..991739e9840 100644
--- a/drivers/vdpa/mlx5/mlx5_vdpa.c
+++ b/drivers/vdpa/mlx5/mlx5_vdpa.c
@@ -693,7 +693,14 @@  mlx5_vdpa_dev_probe(struct rte_device *dev)
 	if (attr.num_lag_ports == 0)
 		priv->num_lag_ports = 1;
 	priv->ctx = ctx;
-	priv->var = mlx5_glue->dv_alloc_var(ctx, 0);
+	for (retry = 0; retry < 7; retry++) {
+		priv->var = mlx5_glue->dv_alloc_var(ctx, 0);
+		if (priv->var != NULL)
+			break;
+		DRV_LOG(WARNING, "Failed to allocate VAR, retry %d.\n", retry);
+		/* Wait Qemu release VAR during vdpa restart, 0.1 sec based. */
+		usleep(100000U << retry);
+	}
 	if (!priv->var) {
 		DRV_LOG(ERR, "Failed to allocate VAR %u.", errno);
 		goto error;