[PATCH 3/3] net/ixgbe: implement VF reset

[luca.boccassi@gmail.com]

From: Luca Boccassi <bluca@debian.org>

This reset function will stop and restart the device, and then reset
the stats and check that the registers have been updated.

Signed-off-by: Luca Boccassi <bluca@debian.org>
---
 drivers/net/ixgbe/ixgbe_ethdev.c | 60 +++++++++++++++++++++++++++++++++++-----
 drivers/net/ixgbe/ixgbe_ethdev.h |  2 +-
 drivers/net/ixgbe/ixgbe_rxtx.c   | 12 ++++++--
 3 files changed, 63 insertions(+), 11 deletions(-)

diff --git a/drivers/net/ixgbe/ixgbe_ethdev.c b/drivers/net/ixgbe/ixgbe_ethdev.c
index 14b9c5303..13307466b 100644
--- a/drivers/net/ixgbe/ixgbe_ethdev.c
+++ b/drivers/net/ixgbe/ixgbe_ethdev.c
@@ -5026,7 +5026,9 @@ ixgbevf_dev_start(struct rte_eth_dev *dev)
 		ETH_VLAN_EXTEND_MASK;
 	ixgbevf_vlan_offload_set(dev, mask);
 
-	ixgbevf_dev_rxtx_start(dev);
+	err = ixgbevf_dev_rxtx_start(dev);
+	if (err)
+		return err;
 
 	/* check and configure queue intr-vector mapping */
 	if (dev->data->dev_conf.intr_conf.rxq != 0) {
@@ -5127,15 +5129,59 @@ ixgbevf_dev_close(struct rte_eth_dev *dev)
 static int
 ixgbevf_dev_reset(struct rte_eth_dev *dev)
 {
-	int ret;
+	struct ixgbe_hw *hw = IXGBE_DEV_PRIVATE_TO_HW(dev->data->dev_private);
+	int diag = 0;
+	uint32_t vteiam;
 
-	ret = eth_ixgbevf_dev_uninit(dev);
-	if (ret)
-		return ret;
+	/* Nothing needs to be done if the device is not started. */
+	if (!dev->data->dev_started)
+		return -EAGAIN;
 
-	ret = eth_ixgbevf_dev_init(dev);
+	PMD_DRV_LOG(DEBUG, "Link up/down event detected.");
 
-	return ret;
+	/* Performance VF reset. */
+	do {
+		dev->data->dev_started = 0;
+		ixgbevf_dev_stop(dev);
+		if (dev->data->dev_conf.intr_conf.lsc == 0)
+			diag = ixgbe_dev_link_update(dev, 0);
+		if (diag) {
+			PMD_INIT_LOG(INFO, "Ixgbe VF reset: "
+					"Failed to update link.");
+		}
+		rte_delay_ms(1000);
+
+		diag = ixgbevf_dev_start(dev);
+		/* If fail to start the device, need to stop/start it again. */
+		if (diag) {
+			PMD_INIT_LOG(ERR, "Ixgbe VF reset: "
+					"Failed to start device.");
+			dev->data->dev_started = 1;
+			return -EAGAIN;
+		}
+		dev->data->dev_started = 1;
+		ixgbevf_dev_stats_reset(dev);
+		if (dev->data->dev_conf.intr_conf.lsc == 0)
+			diag = ixgbe_dev_link_update(dev, 0);
+		if (diag) {
+			PMD_INIT_LOG(INFO, "Ixgbe VF reset: "
+					"Failed to update link.");
+			diag = 0;
+		}
+
+		/**
+		 * When the PF link is down, there is a chance
+		 * that the VF cannot operate its registers.
+		 * Check if the registers are written
+		 * successfully. If not, repeat stop/start until
+		 * the PF link is up, or in other words, until the
+		 * registers can be written.
+		 */
+		vteiam = IXGBE_READ_REG(hw, IXGBE_VTEIAM);
+	/* Reference ixgbevf_intr_enable when checking */
+	} while (diag || vteiam != IXGBE_VF_IRQ_ENABLE_MASK);
+
+	return 0;
 }
 
 static void ixgbevf_set_vfta_all(struct rte_eth_dev *dev, bool on)
diff --git a/drivers/net/ixgbe/ixgbe_ethdev.h b/drivers/net/ixgbe/ixgbe_ethdev.h
index e28c8567e..87b929518 100644
--- a/drivers/net/ixgbe/ixgbe_ethdev.h
+++ b/drivers/net/ixgbe/ixgbe_ethdev.h
@@ -595,7 +595,7 @@ int ixgbevf_dev_rx_init(struct rte_eth_dev *dev);
 
 void ixgbevf_dev_tx_init(struct rte_eth_dev *dev);
 
-void ixgbevf_dev_rxtx_start(struct rte_eth_dev *dev);
+int ixgbevf_dev_rxtx_start(struct rte_eth_dev *dev);
 
 uint16_t ixgbe_recv_pkts(void *rx_queue, struct rte_mbuf **rx_pkts,
 		uint16_t nb_pkts);
diff --git a/drivers/net/ixgbe/ixgbe_rxtx.c b/drivers/net/ixgbe/ixgbe_rxtx.c
index 0038dfbb4..5a0be2cfe 100644
--- a/drivers/net/ixgbe/ixgbe_rxtx.c
+++ b/drivers/net/ixgbe/ixgbe_rxtx.c
@@ -5419,7 +5419,7 @@ ixgbevf_dev_tx_init(struct rte_eth_dev *dev)
 /*
  * [VF] Start Transmit and Receive Units.
  */
-void __attribute__((cold))
+int __attribute__((cold))
 ixgbevf_dev_rxtx_start(struct rte_eth_dev *dev)
 {
 	struct ixgbe_hw     *hw;
@@ -5455,8 +5455,10 @@ ixgbevf_dev_rxtx_start(struct rte_eth_dev *dev)
 			rte_delay_ms(1);
 			txdctl = IXGBE_READ_REG(hw, IXGBE_VFTXDCTL(i));
 		} while (--poll_ms && !(txdctl & IXGBE_TXDCTL_ENABLE));
-		if (!poll_ms)
+		if (!poll_ms) {
 			PMD_INIT_LOG(ERR, "Could not enable Tx Queue %d", i);
+			return -1;
+		}
 	}
 	for (i = 0; i < dev->data->nb_rx_queues; i++) {
 
@@ -5472,12 +5474,16 @@ ixgbevf_dev_rxtx_start(struct rte_eth_dev *dev)
 			rte_delay_ms(1);
 			rxdctl = IXGBE_READ_REG(hw, IXGBE_VFRXDCTL(i));
 		} while (--poll_ms && !(rxdctl & IXGBE_RXDCTL_ENABLE));
-		if (!poll_ms)
+		if (!poll_ms) {
 			PMD_INIT_LOG(ERR, "Could not enable Rx Queue %d", i);
+			return -1;
+		}
 		rte_wmb();
 		IXGBE_WRITE_REG(hw, IXGBE_VFRDT(i), rxq->nb_rx_desc - 1);
 
 	}
+
+	return 0;
 }
 
 /* Stubs needed for linkage when CONFIG_RTE_IXGBE_INC_VECTOR is set to 'n' */
-- 
2.11.0