[dpdk-dev] [PATCH] net/i40e: fix corruption of VF stats via port representor

[Remy Horton]

The resetting of stats on a VF involves the setting of an offset
that is subtracted from future calls, rather zeroing of counters.
However doing a stats reset on the port representor was also
adjusting the values forwarded to the VF, which had the effect of
corrupting the VF's counters. The fix is for the port representor
to maintain its own stats offset, so the port representor and VF
maintain independently-resettable counters

Signed-off-by: Remy Horton <remy.horton at intel.com>
---
 drivers/net/i40e/i40e_ethdev.h         |   2 +
 drivers/net/i40e/i40e_vf_representor.c | 119 +++++++++++++++++++++++++++++++--
 2 files changed, 117 insertions(+), 4 deletions(-)

diff --git a/drivers/net/i40e/i40e_ethdev.h b/drivers/net/i40e/i40e_ethdev.h
index 55c8875..11c4c76 100644
--- a/drivers/net/i40e/i40e_ethdev.h
+++ b/drivers/net/i40e/i40e_ethdev.h
@@ -1083,6 +1083,8 @@ struct i40e_vf_representor {
 	/**< Virtual Function ID */
 	struct i40e_adapter *adapter;
 	/**< Private data store of assocaiated physical function */
+	struct i40e_eth_stats stats_offset;
+	/**< Zero-point of VF statistics*/
 };
 
 extern const struct rte_flow_ops i40e_flow_ops;
diff --git a/drivers/net/i40e/i40e_vf_representor.c b/drivers/net/i40e/i40e_vf_representor.c
index 6026ec9..8dc94b4 100644
--- a/drivers/net/i40e/i40e_vf_representor.c
+++ b/drivers/net/i40e/i40e_vf_representor.c
@@ -139,15 +139,126 @@ i40e_vf_representor_tx_queue_setup(__rte_unused struct rte_eth_dev *dev,
 	return 0;
 }
 
+static void
+i40evf_stat_update_48(uint64_t *offset,
+		   uint64_t *stat)
+{
+	if (*stat >= *offset)
+		*stat = *stat - *offset;
+	else
+		*stat = (uint64_t)((*stat +
+			((uint64_t)1 << I40E_48_BIT_WIDTH)) - *offset);
+
+	*stat &= I40E_48_BIT_MASK;
+}
+
+static void
+i40evf_stat_update_32(uint64_t *offset,
+		   uint64_t *stat)
+{
+	if (*stat >= *offset)
+		*stat = (uint64_t)(*stat - *offset);
+	else
+		*stat = (uint64_t)((*stat +
+			((uint64_t)1 << I40E_32_BIT_WIDTH)) - *offset);
+}
+
+static int
+rte_pmd_i40e_get_vf_native_stats(uint16_t port,
+			  uint16_t vf_id,
+			  struct i40e_eth_stats *stats)
+{
+	struct rte_eth_dev *dev;
+	struct i40e_pf *pf;
+	struct i40e_vsi *vsi;
+
+	RTE_ETH_VALID_PORTID_OR_ERR_RET(port, -ENODEV);
+
+	dev = &rte_eth_devices[port];
+
+	if (!is_i40e_supported(dev))
+		return -ENOTSUP;
+
+	pf = I40E_DEV_PRIVATE_TO_PF(dev->data->dev_private);
+
+	if (vf_id >= pf->vf_num || !pf->vfs) {
+		PMD_DRV_LOG(ERR, "Invalid VF ID.");
+		return -EINVAL;
+	}
+
+	vsi = pf->vfs[vf_id].vsi;
+	if (!vsi) {
+		PMD_DRV_LOG(ERR, "Invalid VSI.");
+		return -EINVAL;
+	}
+
+	i40e_update_vsi_stats(vsi);
+	memcpy(stats, &vsi->eth_stats, sizeof(vsi->eth_stats));
+
+	return 0;
+}
+
 static int
 i40e_vf_representor_stats_get(struct rte_eth_dev *ethdev,
 		struct rte_eth_stats *stats)
 {
 	struct i40e_vf_representor *representor = ethdev->data->dev_private;
+	struct i40e_eth_stats native_stats;
+	int ret;
 
-	return rte_pmd_i40e_get_vf_stats(
+	ret = rte_pmd_i40e_get_vf_native_stats(
 		representor->adapter->eth_dev->data->port_id,
-		representor->vf_id, stats);
+		representor->vf_id, &native_stats);
+	if (ret == 0) {
+		i40evf_stat_update_48(
+			&representor->stats_offset.rx_bytes,
+			&native_stats.rx_bytes);
+		i40evf_stat_update_48(
+			&representor->stats_offset.rx_unicast,
+			&native_stats.rx_unicast);
+		i40evf_stat_update_48(
+			&representor->stats_offset.rx_multicast,
+			&native_stats.rx_multicast);
+		i40evf_stat_update_48(
+			&representor->stats_offset.rx_broadcast,
+			&native_stats.rx_broadcast);
+		i40evf_stat_update_32(
+			&representor->stats_offset.rx_discards,
+			&native_stats.rx_discards);
+		i40evf_stat_update_32(
+			&representor->stats_offset.rx_unknown_protocol,
+			&native_stats.rx_unknown_protocol);
+		i40evf_stat_update_48(
+			&representor->stats_offset.tx_bytes,
+			&native_stats.tx_bytes);
+		i40evf_stat_update_48(
+			&representor->stats_offset.tx_unicast,
+			&native_stats.tx_unicast);
+		i40evf_stat_update_48(
+			&representor->stats_offset.tx_multicast,
+			&native_stats.tx_multicast);
+		i40evf_stat_update_48(
+			&representor->stats_offset.tx_broadcast,
+			&native_stats.tx_broadcast);
+		i40evf_stat_update_32(
+			&representor->stats_offset.tx_errors,
+			&native_stats.tx_errors);
+		i40evf_stat_update_32(
+			&representor->stats_offset.tx_discards,
+			&native_stats.tx_discards);
+
+		stats->ipackets = native_stats.rx_unicast +
+			native_stats.rx_multicast +
+			native_stats.rx_broadcast;
+		stats->opackets = native_stats.tx_unicast +
+			native_stats.tx_multicast +
+			native_stats.tx_broadcast;
+		stats->ibytes   = native_stats.rx_bytes;
+		stats->obytes   = native_stats.tx_bytes;
+		stats->ierrors  = native_stats.rx_discards;
+		stats->oerrors  = native_stats.tx_errors + native_stats.tx_discards;
+	}
+	return ret;
 }
 
 static void
@@ -155,9 +266,9 @@ i40e_vf_representor_stats_reset(struct rte_eth_dev *ethdev)
 {
 	struct i40e_vf_representor *representor = ethdev->data->dev_private;
 
-	rte_pmd_i40e_reset_vf_stats(
+	rte_pmd_i40e_get_vf_native_stats(
 		representor->adapter->eth_dev->data->port_id,
-		representor->vf_id);
+		representor->vf_id, &representor->stats_offset);
 }
 
 static void
-- 
2.9.5