ice: Add automatic VF reset on Tx MDD events

In cases when VF sends malformed packets that are classified as malicious,
it can cause Tx queue to freeze as a result of Malicious Driver Detection
event. Such malformed packets can appear as a result of a faulty userspace
app running on VF. This frozen queue can be stuck for several minutes being
unusable.

User might prefer to immediately bring the VF back to operational state
after such event, which can be done by automatically resetting the VF which
caused MDD. This is already implemented for Rx events (mdd-auto-reset-vf
flag private flag needs to be set).

Extend the VF auto reset to also cover Tx MDD events. When any MDD event
occurs on VF (Tx or Rx) and the mdd-auto-reset-vf private flag is set,
perform a graceful VF reset to quickly bring it back to operational state.

Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Co-developed-by: Liang-Min Wang <liang-min.wang@intel.com>
Signed-off-by: Liang-Min Wang <liang-min.wang@intel.com>
Signed-off-by: Marcin Szycik <marcin.szycik@linux.intel.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 46 insertions, 11 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_main.c b/drivers/net/ethernet/intel/ice/ice_main.c
index 9d751954782c..2b173638b877 100644
--- a/drivers/net/ethernet/intel/ice/ice_main.c
+++ b/drivers/net/ethernet/intel/ice/ice_main.c
@@ -1746,6 +1746,39 @@ static void ice_service_timer(struct timer_list *t)
 }
 
 /**
+ * ice_mdd_maybe_reset_vf - reset VF after MDD event
+ * @pf: pointer to the PF structure
+ * @vf: pointer to the VF structure
+ * @reset_vf_tx: whether Tx MDD has occurred
+ * @reset_vf_rx: whether Rx MDD has occurred
+ *
+ * Since the queue can get stuck on VF MDD events, the PF can be configured to
+ * automatically reset the VF by enabling the private ethtool flag
+ * mdd-auto-reset-vf.
+ */
+static void ice_mdd_maybe_reset_vf(struct ice_pf *pf, struct ice_vf *vf,
+				   bool reset_vf_tx, bool reset_vf_rx)
+{
+	struct device *dev = ice_pf_to_dev(pf);
+
+	if (!test_bit(ICE_FLAG_MDD_AUTO_RESET_VF, pf->flags))
+		return;
+
+	/* VF MDD event counters will be cleared by reset, so print the event
+	 * prior to reset.
+	 */
+	if (reset_vf_tx)
+		ice_print_vf_tx_mdd_event(vf);
+
+	if (reset_vf_rx)
+		ice_print_vf_rx_mdd_event(vf);
+
+	dev_info(dev, "PF-to-VF reset on PF %d VF %d due to MDD event\n",
+		 pf->hw.pf_id, vf->vf_id);
+	ice_reset_vf(vf, ICE_VF_RESET_NOTIFY | ICE_VF_RESET_LOCK);
+}
+
+/**
  * ice_handle_mdd_event - handle malicious driver detect event
  * @pf: pointer to the PF structure
  *
@@ -1838,6 +1871,8 @@ static void ice_handle_mdd_event(struct ice_pf *pf)
 	 */
 	mutex_lock(&pf->vfs.table_lock);
 	ice_for_each_vf(pf, bkt, vf) {
+		bool reset_vf_tx = false, reset_vf_rx = false;
+
 		reg = rd32(hw, VP_MDET_TX_PQM(vf->vf_id));
 		if (reg & VP_MDET_TX_PQM_VALID_M) {
 			wr32(hw, VP_MDET_TX_PQM(vf->vf_id), 0xFFFF);
@@ -1846,6 +1881,8 @@ static void ice_handle_mdd_event(struct ice_pf *pf)
 			if (netif_msg_tx_err(pf))
 				dev_info(dev, "Malicious Driver Detection event TX_PQM detected on VF %d\n",
 					 vf->vf_id);
+
+			reset_vf_tx = true;
 		}
 
 		reg = rd32(hw, VP_MDET_TX_TCLAN(vf->vf_id));
@@ -1856,6 +1893,8 @@ static void ice_handle_mdd_event(struct ice_pf *pf)
 			if (netif_msg_tx_err(pf))
 				dev_info(dev, "Malicious Driver Detection event TX_TCLAN detected on VF %d\n",
 					 vf->vf_id);
+
+			reset_vf_tx = true;
 		}
 
 		reg = rd32(hw, VP_MDET_TX_TDPU(vf->vf_id));
@@ -1866,6 +1905,8 @@ static void ice_handle_mdd_event(struct ice_pf *pf)
 			if (netif_msg_tx_err(pf))
 				dev_info(dev, "Malicious Driver Detection event TX_TDPU detected on VF %d\n",
 					 vf->vf_id);
+
+			reset_vf_tx = true;
 		}
 
 		reg = rd32(hw, VP_MDET_RX(vf->vf_id));
@@ -1877,18 +1918,12 @@ static void ice_handle_mdd_event(struct ice_pf *pf)
 				dev_info(dev, "Malicious Driver Detection event RX detected on VF %d\n",
 					 vf->vf_id);
 
-			/* Since the queue is disabled on VF Rx MDD events, the
-			 * PF can be configured to reset the VF through ethtool
-			 * private flag mdd-auto-reset-vf.
-			 */
-			if (test_bit(ICE_FLAG_MDD_AUTO_RESET_VF, pf->flags)) {
-				/* VF MDD event counters will be cleared by
-				 * reset, so print the event prior to reset.
-				 */
-				ice_print_vf_rx_mdd_event(vf);
-				ice_reset_vf(vf, ICE_VF_RESET_LOCK);
-			}
+			reset_vf_rx = true;
 		}
+
+		if (reset_vf_tx || reset_vf_rx)
+			ice_mdd_maybe_reset_vf(pf, vf, reset_vf_tx,
+					       reset_vf_rx);
 	}
 	mutex_unlock(&pf->vfs.table_lock);