[dpdk-dev] [PATCH v2] ixgbe: add check for tx queue number

[Pablo de Lara <pablo.de.lara.guarch@intel.com>]

IXGBE supports 128 TX queues. However, the full 128 queues
are only available in VT and DCB mode.
In normal default "none" mode (VT/DCB off) the maximum number
of available queues is only 64.
IXGBE doesn't check the mode when reporting the available
number of queues. If a queue larger than 64 is used in default mode,
the TX packets will be dropped silently.

This change adds a check to forbid using a queue number larger than 64
during device configuration (in default mode), so that the problem is
reported as early as possible.
It also changes the order of where the dev_conf parameters are copied
into the dev structure so that the correct maximum number of queues
is reported for the correct mode.

Signed-off-by: Wenzhuo Lu <wenzhuo.lu@intel.com>
Signed-off-by: Pablo de Lara <pablo.de.lara.guarch@intel.com>
---

Changes in v2:

- Reorder memcpy of device configuration in rte_eth_dev_configure(),
  so function gets the correct maximum number of queues
  (depending on the operation mode), before checking the
  requested number of queues.
- Renamed new macro
- Reworded/wrapped commit message

 drivers/net/ixgbe/ixgbe_ethdev.c | 17 ++++++++++++++++-
 drivers/net/ixgbe/ixgbe_ethdev.h |  1 +
 lib/librte_ether/rte_ethdev.c    |  6 +++---
 3 files changed, 20 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c b/drivers/net/ixgbe/ixgbe_ethdev.c
index d4d883a..c799b47 100644
--- a/drivers/net/ixgbe/ixgbe_ethdev.c
+++ b/drivers/net/ixgbe/ixgbe_ethdev.c
@@ -1862,7 +1862,7 @@ ixgbe_check_mq_mode(struct rte_eth_dev *dev)
 {
 	struct rte_eth_conf *dev_conf = &dev->data->dev_conf;
 	uint16_t nb_rx_q = dev->data->nb_rx_queues;
-	uint16_t nb_tx_q = dev->data->nb_rx_queues;
+	uint16_t nb_tx_q = dev->data->nb_tx_queues;
 
 	if (RTE_ETH_DEV_SRIOV(dev).active != 0) {
 		/* check multi-queue mode */
@@ -2002,6 +2002,16 @@ ixgbe_check_mq_mode(struct rte_eth_dev *dev)
 				return -EINVAL;
 			}
 		}
+
+		if (dev_conf->txmode.mq_mode == ETH_MQ_TX_NONE) {
+			if (nb_tx_q > IXGBE_NONE_MODE_TX_NB_QUEUES) {
+				PMD_INIT_LOG(ERR,
+					     "Neither VT nor DCB are enabled, "
+					     "nb_tx_q > %d.",
+					     IXGBE_NONE_MODE_TX_NB_QUEUES);
+				return -EINVAL;
+			}
+		}
 	}
 	return 0;
 }
@@ -2856,9 +2866,14 @@ static void
 ixgbe_dev_info_get(struct rte_eth_dev *dev, struct rte_eth_dev_info *dev_info)
 {
 	struct ixgbe_hw *hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
+	struct rte_eth_conf *dev_conf = &dev->data->dev_conf;
 
 	dev_info->max_rx_queues = (uint16_t)hw->mac.max_rx_queues;
 	dev_info->max_tx_queues = (uint16_t)hw->mac.max_tx_queues;
+	if (RTE_ETH_DEV_SRIOV(dev).active == 0) {
+		if (dev_conf->txmode.mq_mode == ETH_MQ_TX_NONE)
+			dev_info->max_tx_queues = IXGBE_NONE_MODE_TX_NB_QUEUES;
+	}
 	dev_info->min_rx_bufsize = 1024; /* cf BSIZEPACKET in SRRCTL register */
 	dev_info->max_rx_pktlen = 15872; /* includes CRC, cf MAXFRS register */
 	dev_info->max_mac_addrs = hw->mac.num_rar_entries;
diff --git a/drivers/net/ixgbe/ixgbe_ethdev.h b/drivers/net/ixgbe/ixgbe_ethdev.h
index 5c3aa16..691c62f 100644
--- a/drivers/net/ixgbe/ixgbe_ethdev.h
+++ b/drivers/net/ixgbe/ixgbe_ethdev.h
@@ -61,6 +61,7 @@
 #define IXGBE_MAX_RX_QUEUE_NUM	128
 #define IXGBE_VMDQ_DCB_NB_QUEUES     IXGBE_MAX_RX_QUEUE_NUM
 #define IXGBE_DCB_NB_QUEUES          IXGBE_MAX_RX_QUEUE_NUM
+#define IXGBE_NONE_MODE_TX_NB_QUEUES 64
 
 #ifndef NBBY
 #define NBBY	8	/* number of bits in a byte */
diff --git a/lib/librte_ether/rte_ethdev.c b/lib/librte_ether/rte_ethdev.c
index 8721a6b..b941b0d 100644
--- a/lib/librte_ether/rte_ethdev.c
+++ b/lib/librte_ether/rte_ethdev.c
@@ -901,6 +901,9 @@ rte_eth_dev_configure(uint8_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
 		return -EBUSY;
 	}
 
+	/* Copy the dev_conf parameter into the dev structure */
+	memcpy(&dev->data->dev_conf, dev_conf, sizeof(dev->data->dev_conf));
+
 	/*
 	 * Check that the numbers of RX and TX queues are not greater
 	 * than the maximum number of RX and TX queues supported by the
@@ -925,9 +928,6 @@ rte_eth_dev_configure(uint8_t port_id, uint16_t nb_rx_q, uint16_t nb_tx_q,
 		return -EINVAL;
 	}
 
-	/* Copy the dev_conf parameter into the dev structure */
-	memcpy(&dev->data->dev_conf, dev_conf, sizeof(dev->data->dev_conf));
-
 	/*
 	 * If link state interrupt is enabled, check that the
 	 * device supports it.
-- 
2.5.5