ice: warn about potentially malicious VFs

Attempt to detect malicious VFs and, if suspected, log the information but
keep going to allow the user to take any desired actions.

Potentially malicious VFs are identified by checking if the VFs are
transmitting too many messages via the PF-VF mailbox which could cause an
overflow of this channel resulting in denial of service. This is done by
creating a snapshot or static capture of the mailbox buffer which can be
traversed and in which the messages sent by VFs are tracked.

Co-developed-by: Yashaswini Raghuram Prathivadi Bhayankaram <yashaswini.raghuram.prathivadi.bhayankaram@intel.com>
Signed-off-by: Yashaswini Raghuram Prathivadi Bhayankaram <yashaswini.raghuram.prathivadi.bhayankaram@intel.com>
Co-developed-by: Paul M Stillwell Jr <paul.m.stillwell.jr@intel.com>
Signed-off-by: Paul M Stillwell Jr <paul.m.stillwell.jr@intel.com>
Co-developed-by: Brett Creeley <brett.creeley@intel.com>
Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Signed-off-by: Vignesh Sridhar <vignesh.sridhar@intel.com>
Tested-by: Konrad Jankowski <konrad0.jankowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>

1 files changed, 93 insertions, 1 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c b/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c
index e38d4adc5b8d..a3ed4b84bba6 100644
--- a/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c
+++ b/drivers/net/ethernet/intel/ice/ice_virtchnl_pf.c
@@ -424,6 +424,14 @@ void ice_free_vfs(struct ice_pf *pf)
 			wr32(hw, GLGEN_VFLRSTAT(reg_idx), BIT(bit_idx));
 		}
 	}
+
+	/* clear malicious info if the VFs are getting released */
+	for (i = 0; i < tmp; i++)
+		if (ice_mbx_clear_malvf(&hw->mbx_snapshot, pf->malvfs,
+					ICE_MAX_VF_COUNT, i))
+			dev_dbg(dev, "failed to clear malicious VF state for VF %u\n",
+				i);
+
 	clear_bit(ICE_VF_DIS, pf->state);
 	clear_bit(ICE_FLAG_SRIOV_ENA, pf->flags);
 }
@@ -1257,6 +1265,11 @@ bool ice_reset_all_vfs(struct ice_pf *pf, bool is_vflr)
 	if (!pf->num_alloc_vfs)
 		return false;
 
+	/* clear all malicious info if the VFs are getting reset */
+	ice_for_each_vf(pf, i)
+		if (ice_mbx_clear_malvf(&hw->mbx_snapshot, pf->malvfs, ICE_MAX_VF_COUNT, i))
+			dev_dbg(dev, "failed to clear malicious VF state for VF %u\n", i);
+
 	/* If VFs have been disabled, there is no need to reset */
 	if (test_and_set_bit(ICE_VF_DIS, pf->state))
 		return false;
@@ -1437,6 +1450,10 @@ bool ice_reset_vf(struct ice_vf *vf, bool is_vflr)
 	ice_vf_rebuild_vsi_with_release(vf);
 	ice_vf_post_vsi_rebuild(vf);
 
+	/* if the VF has been reset allow it to come up again */
+	if (ice_mbx_clear_malvf(&hw->mbx_snapshot, pf->malvfs, ICE_MAX_VF_COUNT, vf->vf_id))
+		dev_dbg(dev, "failed to clear malicious VF state for VF %u\n", i);
+
 	return true;
 }
 
@@ -1769,6 +1786,7 @@ int ice_sriov_configure(struct pci_dev *pdev, int num_vfs)
 {
 	struct ice_pf *pf = pci_get_drvdata(pdev);
 	struct device *dev = ice_pf_to_dev(pf);
+	enum ice_status status;
 	int err;
 
 	err = ice_check_sriov_allowed(pf);
@@ -1777,6 +1795,7 @@ int ice_sriov_configure(struct pci_dev *pdev, int num_vfs)
 
 	if (!num_vfs) {
 		if (!pci_vfs_assigned(pdev)) {
+			ice_mbx_deinit_snapshot(&pf->hw);
 			ice_free_vfs(pf);
 			if (pf->lag)
 				ice_enable_lag(pf->lag);
@@ -1787,9 +1806,15 @@ int ice_sriov_configure(struct pci_dev *pdev, int num_vfs)
 		return -EBUSY;
 	}
 
+	status = ice_mbx_init_snapshot(&pf->hw, num_vfs);
+	if (status)
+		return ice_status_to_errno(status);
+
 	err = ice_pci_sriov_ena(pf, num_vfs);
-	if (err)
+	if (err) {
+		ice_mbx_deinit_snapshot(&pf->hw);
 		return err;
+	}
 
 	if (pf->lag)
 		ice_disable_lag(pf->lag);
@@ -4255,3 +4280,70 @@ void ice_restore_all_vfs_msi_state(struct pci_dev *pdev)
 		}
 	}
 }
+
+/**
+ * ice_is_malicious_vf - helper function to detect a malicious VF
+ * @pf: ptr to struct ice_pf
+ * @event: pointer to the AQ event
+ * @num_msg_proc: the number of messages processed so far
+ * @num_msg_pending: the number of messages peinding in admin queue
+ */
+bool
+ice_is_malicious_vf(struct ice_pf *pf, struct ice_rq_event_info *event,
+		    u16 num_msg_proc, u16 num_msg_pending)
+{
+	s16 vf_id = le16_to_cpu(event->desc.retval);
+	struct device *dev = ice_pf_to_dev(pf);
+	struct ice_mbx_data mbxdata;
+	enum ice_status status;
+	bool malvf = false;
+	struct ice_vf *vf;
+
+	if (ice_validate_vf_id(pf, vf_id))
+		return false;
+
+	vf = &pf->vf[vf_id];
+	/* Check if VF is disabled. */
+	if (test_bit(ICE_VF_STATE_DIS, vf->vf_states))
+		return false;
+
+	mbxdata.num_msg_proc = num_msg_proc;
+	mbxdata.num_pending_arq = num_msg_pending;
+	mbxdata.max_num_msgs_mbx = pf->hw.mailboxq.num_rq_entries;
+#define ICE_MBX_OVERFLOW_WATERMARK 64
+	mbxdata.async_watermark_val = ICE_MBX_OVERFLOW_WATERMARK;
+
+	/* check to see if we have a malicious VF */
+	status = ice_mbx_vf_state_handler(&pf->hw, &mbxdata, vf_id, &malvf);
+	if (status)
+		return false;
+
+	if (malvf) {
+		bool report_vf = false;
+
+		/* if the VF is malicious and we haven't let the user
+		 * know about it, then let them know now
+		 */
+		status = ice_mbx_report_malvf(&pf->hw, pf->malvfs,
+					      ICE_MAX_VF_COUNT, vf_id,
+					      &report_vf);
+		if (status)
+			dev_dbg(dev, "Error reporting malicious VF\n");
+
+		if (report_vf) {
+			struct ice_vsi *pf_vsi = ice_get_main_vsi(pf);
+
+			if (pf_vsi)
+				dev_warn(dev, "VF MAC %pM on PF MAC %pM is generating asynchronous messages and may be overflowing the PF message queue. Please see the Adapter User Guide for more information\n",
+					 &vf->dflt_lan_addr.addr[0],
+					 pf_vsi->netdev->dev_addr);
+		}
+
+		return true;
+	}
+
+	/* if there was an error in detection or the VF is not malicious then
+	 * return false
+	 */
+	return false;
+}