iavf: Fix 'tc qdisc show' listing too many queues

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@intel.com>
Co-developed-by: Grzegorz Szczurek <grzegorzx.szczurek@intel.com>
Signed-off-by: Grzegorz Szczurek <grzegorzx.szczurek@intel.com>
Co-developed-by: Kiran Patil <kiran.patil@intel.com>
Signed-off-by: Kiran Patil <kiran.patil@intel.com>
Signed-off-by: Jedrzej Jagielski <jedrzej.jagielski@intel.com>
Tested-by: Bharathi Sreenivas <bharathi.sreenivas@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 5 insertions, 0 deletions

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;