iavf: Fix max_rate limiting

[ Upstream commit ec60d54cb9a3d43a02c5612a03093c18233e6601 ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/net/ethernet/intel/iavf/iavf.h b/drivers/net/ethernet/intel/iavf/iavf.h
index 9a122aea69793a84371dabb2cf3a27360a643834..ab84fc83352fb593816f03d5722f87411a48e52e 100644 (file)
--- a/drivers/net/ethernet/intel/iavf/iavf.h
+++ b/drivers/net/ethernet/intel/iavf/iavf.h
@@ -89,6 +89,7 @@ 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 ca74824d40b8548790d0ee4137ed54cfc002a445..067f0b265e7d689790b2a7bcab0667a03aa19474 100644 (file)
--- a/drivers/net/ethernet/intel/iavf/iavf_main.c
+++ b/drivers/net/ethernet/intel/iavf/iavf_main.c
@@ -2732,6 +2732,7 @@ 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;
@@ -2746,12 +2747,32 @@ 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];
        }