[dpdk-stable] patch 'net/mlx4: check RSS queues number limitation' has been queued to stable release 18.05.1

[Christian Ehrhardt <christian.ehrhardt@canonical.com>]

Hi,

FYI, your patch has been queued to stable release 18.05.1

Note it hasn't been pushed to http://dpdk.org/browse/dpdk-stable yet.
It will be pushed if I get no objections before 08/16/18. So please
shout if anyone has objections.

Thanks.

Christian Ehrhardt <christian.ehrhardt@canonical.com>

---
>From 0fdc12d793e1331be2f4eaa0c1be11712dd6c3ec Mon Sep 17 00:00:00 2001
From: Moti Haimovsky <motih@mellanox.com>
Date: Wed, 25 Jul 2018 17:47:39 +0300
Subject: [PATCH] net/mlx4: check RSS queues number limitation

[ upstream commit 2b4e423fd4c9ed5b0a4d1a0962f4af653b7324c5 ]

This patch verifies that the number of Rx queues configured for RSS
is supported by the device hardware.
RSS support in mlx4 requires contiguous chunk of QPs to be reserved,
there is a hardware limitation on the amount of contiguous QPs which
is reported by the hardware. Ignoring this value will cause Rx queues
creation to fail.

Signed-off-by: Moti Haimovsky <motih@mellanox.com>
Acked-by: Matan Azrad <matan@mellanox.com>
---
 drivers/net/mlx4/mlx4.c     | 3 +++
 drivers/net/mlx4/mlx4.h     | 1 +
 drivers/net/mlx4/mlx4_rxq.c | 6 ++++++
 3 files changed, 10 insertions(+)

diff --git a/drivers/net/mlx4/mlx4.c b/drivers/net/mlx4/mlx4.c
index d151a9055..7cbe1e734 100644
--- a/drivers/net/mlx4/mlx4.c
+++ b/drivers/net/mlx4/mlx4.c
@@ -673,6 +673,9 @@ mlx4_pci_probe(struct rte_pci_driver *pci_drv, struct rte_pci_device *pci_dev)
 						   &device_attr_ex);
 		DEBUG("supported RSS hash fields mask: %016" PRIx64,
 		      priv->hw_rss_sup);
+		priv->hw_rss_max_qps =
+			device_attr_ex.rss_caps.max_rwq_indirection_table_size;
+		DEBUG("MAX RSS queues %d", priv->hw_rss_max_qps);
 		priv->hw_fcs_strip = !!(device_attr_ex.raw_packet_caps &
 					IBV_RAW_PACKET_CAP_SCATTER_FCS);
 		DEBUG("FCS stripping toggling is %ssupported",
diff --git a/drivers/net/mlx4/mlx4.h b/drivers/net/mlx4/mlx4.h
index 300cb4d7a..2f8ea3c4c 100644
--- a/drivers/net/mlx4/mlx4.h
+++ b/drivers/net/mlx4/mlx4.h
@@ -90,6 +90,7 @@ struct priv {
 	uint32_t hw_csum:1; /**< Checksum offload is supported. */
 	uint32_t hw_csum_l2tun:1; /**< Checksum support for L2 tunnels. */
 	uint32_t hw_fcs_strip:1; /**< FCS stripping toggling is supported. */
+	uint32_t hw_rss_max_qps; /**< Max Rx Queues supported by RSS. */
 	uint64_t hw_rss_sup; /**< Supported RSS hash fields (Verbs format). */
 	struct rte_intr_handle intr_handle; /**< Port interrupt handle. */
 	struct mlx4_drop *drop; /**< Shared resources for drop flow rules. */
diff --git a/drivers/net/mlx4/mlx4_rxq.c b/drivers/net/mlx4/mlx4_rxq.c
index 87688c1c7..e0867040f 100644
--- a/drivers/net/mlx4/mlx4_rxq.c
+++ b/drivers/net/mlx4/mlx4_rxq.c
@@ -338,6 +338,12 @@ mlx4_rss_init(struct priv *priv)
 
 	if (priv->rss_init)
 		return 0;
+	if (priv->dev->data->nb_rx_queues > priv->hw_rss_max_qps) {
+		ERROR("RSS does not support more than %d queues",
+		      priv->hw_rss_max_qps);
+		rte_errno = EINVAL;
+		return -rte_errno;
+	}
 	/* Prepare range for RSS contexts before creating the first WQ. */
 	ret = mlx4_glue->dv_set_context_attr
 		(priv->ctx,
-- 
2.17.1