[PATCH 5.18 0530/1095] iavf: Fix tc qdisc show listing too many queues

[Greg Kroah-Hartman]

From: Przemyslaw Patynowski <przemyslawx.patynowski@xxxxxxxxx>

[ Upstream commit 93cb804edab1b9a5bb7bb7b6824012dbb20abf22 ]

Fix tc qdisc show dev <ethX> root displaying too many fq_codel qdiscs.
tc_modify_qdisc, which is caller of ndo_setup_tc, expects driver to call
netif_set_real_num_tx_queues, which prepares qdiscs.
Without this patch, fq_codel qdiscs would not be adjusted to number of
queues on VF.
e.g.:
tc qdisc show dev <ethX>
qdisc mq 0: root
qdisc fq_codel 0: parent :4 limit 10240p flows 1024 quantum 1514 target 5ms interval 100ms memory_limit 32Mb ecn drop_batch 64
qdisc fq_codel 0: parent :3 limit 10240p flows 1024 quantum 1514 target 5ms interval 100ms memory_limit 32Mb ecn drop_batch 64
qdisc fq_codel 0: parent :2 limit 10240p flows 1024 quantum 1514 target 5ms interval 100ms memory_limit 32Mb ecn drop_batch 64
qdisc fq_codel 0: parent :1 limit 10240p flows 1024 quantum 1514 target 5ms interval 100ms memory_limit 32Mb ecn drop_batch 64
tc qdisc add dev <ethX> root mqprio num_tc 2 map 1 0 0 0 0 0 0 0 queues 1@0 1@1 hw 1 mode channel shaper bw_rlimit max_rate 5000Mbit 150Mbit
tc qdisc show dev <ethX>
qdisc mqprio 8003: root tc 2 map 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
             queues:(0:0) (1:1)
             mode:channel
             shaper:bw_rlimit   max_rate:5Gbit 150Mbit
qdisc fq_codel 0: parent 8003:4 limit 10240p flows 1024 quantum 1514 target 5ms interval 100ms memory_limit 32Mb ecn drop_batch 64
qdisc fq_codel 0: parent 8003:3 limit 10240p flows 1024 quantum 1514 target 5ms interval 100ms memory_limit 32Mb ecn drop_batch 64
qdisc fq_codel 0: parent 8003:2 limit 10240p flows 1024 quantum 1514 target 5ms interval 100ms memory_limit 32Mb ecn drop_batch 64
qdisc fq_codel 0: parent 8003:1 limit 10240p flows 1024 quantum 1514 target 5ms interval 100ms memory_limit 32Mb ecn drop_batch 64

While after fix:
tc qdisc add dev <ethX> root mqprio num_tc 2 map 1 0 0 0 0 0 0 0 queues 1@0 1@1 hw 1 mode channel shaper bw_rlimit max_rate 5000Mbit 150Mbit
tc qdisc show dev <ethX> #should show 2, shows 4
qdisc mqprio 8004: root tc 2 map 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
             queues:(0:0) (1:1)
             mode:channel
             shaper:bw_rlimit   max_rate:5Gbit 150Mbit
qdisc fq_codel 0: parent 8004:2 limit 10240p flows 1024 quantum 1514 target 5ms interval 100ms memory_limit 32Mb ecn drop_batch 64
qdisc fq_codel 0: parent 8004:1 limit 10240p flows 1024 quantum 1514 target 5ms interval 100ms memory_limit 32Mb ecn drop_batch 64

Fixes: d5b33d024496 ("i40evf: add ndo_setup_tc callback to i40evf")
Signed-off-by: Przemyslaw Patynowski <przemyslawx.patynowski@xxxxxxxxx>
Co-developed-by: Grzegorz Szczurek <grzegorzx.szczurek@xxxxxxxxx>
Signed-off-by: Grzegorz Szczurek <grzegorzx.szczurek@xxxxxxxxx>
Co-developed-by: Kiran Patil <kiran.patil@xxxxxxxxx>
Signed-off-by: Kiran Patil <kiran.patil@xxxxxxxxx>
Signed-off-by: Jedrzej Jagielski <jedrzej.jagielski@xxxxxxxxx>
Tested-by: Bharathi Sreenivas <bharathi.sreenivas@xxxxxxxxx>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/net/ethernet/intel/iavf/iavf.h      |  5 +++++
 drivers/net/ethernet/intel/iavf/iavf_main.c | 21 +++++++++++++++++++++
 2 files changed, 26 insertions(+)

diff --git a/drivers/net/ethernet/intel/iavf/iavf.h b/drivers/net/ethernet/intel/iavf/iavf.h
index c241fbc30f93..a988c08e906f 100644
--- a/drivers/net/ethernet/intel/iavf/iavf.h
+++ b/drivers/net/ethernet/intel/iavf/iavf.h
@@ -431,6 +431,11 @@ struct iavf_adapter {
 	/* lock to protect access to the cloud filter list */
 	spinlock_t cloud_filter_list_lock;
 	u16 num_cloud_filters;
+	/* snapshot of "num_active_queues" before setup_tc for qdisc add
+	 * is invoked. This information is useful during qdisc del flow,
+	 * to restore correct number of queues
+	 */
+	int orig_num_active_queues;
 
 #define IAVF_MAX_FDIR_FILTERS 128	/* max allowed Flow Director filters */
 	u16 fdir_active_fltr;
diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
index 51ae10eb348c..3dbfaead2ac7 100644
--- a/drivers/net/ethernet/intel/iavf/iavf_main.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
@@ -3429,6 +3429,7 @@ static int __iavf_setup_tc(struct net_device *netdev, void *type_data)
 			netif_tx_disable(netdev);
 			iavf_del_all_cloud_filters(adapter);
 			adapter->aq_required = IAVF_FLAG_AQ_DISABLE_CHANNELS;
+			total_qps = adapter->orig_num_active_queues;
 			goto exit;
 		} else {
 			return -EINVAL;
@@ -3472,7 +3473,21 @@ static int __iavf_setup_tc(struct net_device *netdev, void *type_data)
 				adapter->ch_config.ch_info[i].offset = 0;
 			}
 		}
+
+		/* Take snapshot of original config such as "num_active_queues"
+		 * It is used later when delete ADQ flow is exercised, so that
+		 * once delete ADQ flow completes, VF shall go back to its
+		 * original queue configuration
+		 */
+
+		adapter->orig_num_active_queues = adapter->num_active_queues;
+
+		/* Store queue info based on TC so that VF gets configured
+		 * with correct number of queues when VF completes ADQ config
+		 * flow
+		 */
 		adapter->ch_config.total_qps = total_qps;
+
 		netif_tx_stop_all_queues(netdev);
 		netif_tx_disable(netdev);
 		adapter->aq_required |= IAVF_FLAG_AQ_ENABLE_CHANNELS;
@@ -3489,6 +3504,12 @@ static int __iavf_setup_tc(struct net_device *netdev, void *type_data)
 		}
 	}
 exit:
+	if (test_bit(__IAVF_IN_REMOVE_TASK, &adapter->crit_section))
+		return 0;
+
+	netif_set_real_num_rx_queues(netdev, total_qps);
+	netif_set_real_num_tx_queues(netdev, total_qps);
+
 	return ret;
 }
 
-- 
2.35.1