iavf: Fix max_rate limiting

Fix max_rate option in TC, check for proper quanta boundaries.
Check for minimum value provided and if it fits expected 50Mbps
quanta.

Without this patch, iavf could send settings for max_rate limiting
that would be accepted from by PF even the max_rate option is less
than expected 50Mbps quanta. It results in no rate limiting
on traffic as rate limiting will be floored to 0.

Example:
tc qdisc add dev $vf root mqprio num_tc 3 map 0 2 1 queues \
2@0 2@2 2@4 hw 1 mode channel shaper bw_rlimit \
max_rate 50Mbps 500Mbps 500Mbps

Should limit TC0 to circa 50 Mbps

tc qdisc add dev $vf root mqprio num_tc 3 map 0 2 1 queues \
2@0 2@2 2@4 hw 1 mode channel shaper bw_rlimit \
max_rate 0Mbps 100Kbit 500Mbps

Should return error

Fixes: d5b33d024496 ("i40evf: add ndo_setup_tc callback to i40evf")
Signed-off-by: Przemyslaw Patynowski <przemyslawx.patynowski@intel.com>
Signed-off-by: Jun Zhang <xuejun.zhang@intel.com>
Tested-by: Bharathi Sreenivas <bharathi.sreenivas@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

diff --git a/drivers/net/ethernet/intel/iavf/iavf.h b/drivers/net/ethernet/intel/iavf/iavf.h
index 0ea0361cd86b1f98c21291051c8c52cff9576295..c241fbc30f93f4627b39924594f813a48779da9c 100644 (file)
--- a/drivers/net/ethernet/intel/iavf/iavf.h
+++ b/drivers/net/ethernet/intel/iavf/iavf.h
@@ -92,6 +92,7 @@ struct iavf_vsi {
 #define IAVF_HKEY_ARRAY_SIZE ((IAVF_VFQF_HKEY_MAX_INDEX + 1) * 4)
 #define IAVF_HLUT_ARRAY_SIZE ((IAVF_VFQF_HLUT_MAX_INDEX + 1) * 4)
 #define IAVF_MBPS_DIVISOR      125000 /* divisor to convert to Mbps */
+#define IAVF_MBPS_QUANTA       50
 
 #define IAVF_VIRTCHNL_VF_RESOURCE_SIZE (sizeof(struct virtchnl_vf_resource) + \
                                        (IAVF_MAX_VF_VSI * \

diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c
index 2e2c153ce46a3c791b0aedc73e61077478cf50c8..51ae10eb348cfc2fbcb4511d5b77fb63dbcbc111 100644 (file)
--- a/drivers/net/ethernet/intel/iavf/iavf_main.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
@@ -3322,6 +3322,7 @@ static int iavf_validate_ch_config(struct iavf_adapter *adapter,
                                   struct tc_mqprio_qopt_offload *mqprio_qopt)
 {
        u64 total_max_rate = 0;
+       u32 tx_rate_rem = 0;
        int i, num_qps = 0;
        u64 tx_rate = 0;
        int ret = 0;
@@ -3336,12 +3337,32 @@ static int iavf_validate_ch_config(struct iavf_adapter *adapter,
                        return -EINVAL;
                if (mqprio_qopt->min_rate[i]) {
                        dev_err(&adapter->pdev->dev,
-                               "Invalid min tx rate (greater than 0) specified\n");
+                               "Invalid min tx rate (greater than 0) specified for TC%d\n",
+                               i);
                        return -EINVAL;
                }
-               /*convert to Mbps */
+
+               /* convert to Mbps */
                tx_rate = div_u64(mqprio_qopt->max_rate[i],
                                  IAVF_MBPS_DIVISOR);
+
+               if (mqprio_qopt->max_rate[i] &&
+                   tx_rate < IAVF_MBPS_QUANTA) {
+                       dev_err(&adapter->pdev->dev,
+                               "Invalid max tx rate for TC%d, minimum %dMbps\n",
+                               i, IAVF_MBPS_QUANTA);
+                       return -EINVAL;
+               }
+
+               (void)div_u64_rem(tx_rate, IAVF_MBPS_QUANTA, &tx_rate_rem);
+
+               if (tx_rate_rem != 0) {
+                       dev_err(&adapter->pdev->dev,
+                               "Invalid max tx rate for TC%d, not divisible by %d\n",
+                               i, IAVF_MBPS_QUANTA);
+                       return -EINVAL;
+               }
+
                total_max_rate += tx_rate;
                num_qps += mqprio_qopt->qopt.count[i];
        }