[dpdk-dev] [PATCH v3] ixgbe: add check for tx queue number

[Pablo de Lara]

From: Wenzhuo Lu <wenzhuo.lu at 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
(except for 82598EB, which is 32 for all modes).

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 at intel.com>
Signed-off-by: Pablo de Lara <pablo.de.lara.guarch at intel.com>
---

Respin for automated testing.
Will send a v4 splitting the patch.

Changes in v3:
- Fixed wrong set of TX queues for 82596EB

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 | 28 +++++++++++++++++++++++++++-
 drivers/net/ixgbe/ixgbe_ethdev.h |  1 +
 lib/librte_ether/rte_ethdev.c    |  6 +++---
 3 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c b/drivers/net/ixgbe/ixgbe_ethdev.c
index d4d883a..bfd8cb3 100644
--- a/drivers/net/ixgbe/ixgbe_ethdev.c
+++ b/drivers/net/ixgbe/ixgbe_ethdev.c
@@ -1861,8 +1861,9 @@ static int
 ixgbe_check_mq_mode(struct rte_eth_dev *dev)
 {
 	struct rte_eth_conf *dev_conf = &dev->data->dev_conf;
+	struct ixgbe_hw *hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
 	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 +2003,21 @@ ixgbe_check_mq_mode(struct rte_eth_dev *dev)
 				return -EINVAL;
 			}
 		}
+
+		/*
+		 * When DCB/VT is off, maximum number of queues changes,
+		 * except for 82598EB, which remains constant.
+		 */
+		if (dev_conf->txmode.mq_mode == ETH_MQ_TX_NONE &&
+				hw->mac.type != ixgbe_mac_82598EB) {
+			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 +2872,19 @@ 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) {
+		/*
+		 * When DCB/VT is off, maximum number of queues changes,
+		 * except for 82598EB, which remains constant.
+		 */
+		if (dev_conf->txmode.mq_mode == ETH_MQ_TX_NONE &&
+				hw->mac.type != ixgbe_mac_82598EB)
+			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