[v3,net-next,08/15] net/sched: mqprio: allow offloading drivers to request queue count validation

Commit Message

Vladimir Oltean Jan. 27, 2023, 12:15 a.m. UTC

mqprio_parse_opt() proudly has a comment:

	/* If hardware offload is requested we will leave it to the device
	 * to either populate the queue counts itself or to validate the
	 * provided queue counts.
	 */

Unfortunately some device drivers did not get this memo, and don't
validate the queue counts.

Introduce a tc capability, and make mqprio query it.

Signed-off-by: Vladimir Oltean <[e-mail]>
Reviewed-by: Jacob Keller <[e-mail]>
---
v1->v3: none

 include/net/pkt_sched.h |  4 +++
 net/sched/sch_mqprio.c  | 58 +++++++++++++++++++++++++++--------------
 2 files changed, 42 insertions(+), 20 deletions(-)

Patch

diff --git a/include/net/pkt_sched.h b/include/net/pkt_sched.h
index 6c5e64e0a0bb..02e3ccfbc7d1 100644
--- a/include/net/pkt_sched.h
+++ b/include/net/pkt_sched.h
@@ -160,6 +160,10 @@  struct tc_etf_qopt_offload {
 	s32 queue;
 };
 
+struct tc_mqprio_caps {
+	bool validate_queue_counts:1;
+};
+
 struct tc_mqprio_qopt_offload {
 	/* struct tc_mqprio_qopt must always be the first element */
 	struct tc_mqprio_qopt qopt;
diff --git a/net/sched/sch_mqprio.c b/net/sched/sch_mqprio.c
index 3579a64da06e..5fdceab82ea1 100644
--- a/net/sched/sch_mqprio.c
+++ b/net/sched/sch_mqprio.c
@@ -27,14 +27,50 @@  struct mqprio_sched {
 	u64 max_rate[TC_QOPT_MAX_QUEUE];
 };
 
+static int mqprio_validate_queue_counts(struct net_device *dev,
+					const struct tc_mqprio_qopt *qopt)
+{
+	int i, j;
+
+	for (i = 0; i < qopt->num_tc; i++) {
+		unsigned int last = qopt->offset[i] + qopt->count[i];
+
+		/* Verify the queue count is in tx range being equal to the
+		 * real_num_tx_queues indicates the last queue is in use.
+		 */
+		if (qopt->offset[i] >= dev->real_num_tx_queues ||
+		    !qopt->count[i] ||
+		    last > dev->real_num_tx_queues)
+			return -EINVAL;
+
+		/* Verify that the offset and counts do not overlap */
+		for (j = i + 1; j < qopt->num_tc; j++) {
+			if (last > qopt->offset[j])
+				return -EINVAL;
+		}
+	}
+
+	return 0;
+}
+
 static int mqprio_enable_offload(struct Qdisc *sch,
 				 const struct tc_mqprio_qopt *qopt)
 {
 	struct tc_mqprio_qopt_offload mqprio = {.qopt = *qopt};
 	struct mqprio_sched *priv = qdisc_priv(sch);
 	struct net_device *dev = qdisc_dev(sch);
+	struct tc_mqprio_caps caps;
 	int err, i;
 
+	qdisc_offload_query_caps(dev, TC_SETUP_QDISC_MQPRIO,
+				 &caps, sizeof(caps));
+
+	if (caps.validate_queue_counts) {
+		err = mqprio_validate_queue_counts(dev, qopt);
+		if (err)
+			return err;
+	}
+
 	switch (priv->mode) {
 	case TC_MQPRIO_MODE_DCB:
 		if (priv->shaper != TC_MQPRIO_SHAPER_DCB)
@@ -104,7 +140,7 @@  static void mqprio_destroy(struct Qdisc *sch)
 
 static int mqprio_parse_opt(struct net_device *dev, struct tc_mqprio_qopt *qopt)
 {
-	int i, j;
+	int i;
 
 	/* Verify num_tc is not out of max range */
 	if (qopt->num_tc > TC_MAX_QUEUE)
@@ -131,25 +167,7 @@  static int mqprio_parse_opt(struct net_device *dev, struct tc_mqprio_qopt *qopt)
 	if (qopt->hw)
 		return dev->netdev_ops->ndo_setup_tc ? 0 : -EINVAL;
 
-	for (i = 0; i < qopt->num_tc; i++) {
-		unsigned int last = qopt->offset[i] + qopt->count[i];
-
-		/* Verify the queue count is in tx range being equal to the
-		 * real_num_tx_queues indicates the last queue is in use.
-		 */
-		if (qopt->offset[i] >= dev->real_num_tx_queues ||
-		    !qopt->count[i] ||
-		    last > dev->real_num_tx_queues)
-			return -EINVAL;
-
-		/* Verify that the offset and counts do not overlap */
-		for (j = i + 1; j < qopt->num_tc; j++) {
-			if (last > qopt->offset[j])
-				return -EINVAL;
-		}
-	}
-
-	return 0;
+	return mqprio_validate_queue_counts(dev, qopt);
 }
 
 static const struct nla_policy mqprio_policy[TCA_MQPRIO_MAX + 1] = {