ice: add E830 HW VF mailbox message limit support

E830 adds hardware support to prevent the VF from overflowing the PF
mailbox with VIRTCHNL messages. E830 will use the hardware feature
(ICE_F_MBX_LIMIT) instead of the software solution ice_is_malicious_vf().

To prevent a VF from overflowing the PF, the PF sets the number of
messages per VF that can be in the PF's mailbox queue
(ICE_MBX_OVERFLOW_WATERMARK). When the PF processes a message from a VF,
the PF decrements the per VF message count using the E830_MBX_VF_DEC_TRIG
register.

Signed-off-by: Paul Greenwalt <[email protected]>
Reviewed-by: Alexander Lobakin <[email protected]>
Tested-by: Rafal Romanowski <[email protected]>
Signed-off-by: Tony Nguyen <[email protected]>

1 files changed, 2 insertions, 1 deletions

diff --git a/drivers/net/ethernet/intel/ice/ice_sriov.c b/drivers/net/ethernet/intel/ice/ice_sriov.c
index e34fe2516ccc..e7b5fe553d1f 100644
--- a/drivers/net/ethernet/intel/ice/ice_sriov.c
+++ b/drivers/net/ethernet/intel/ice/ice_sriov.c
@@ -194,7 +194,8 @@ void ice_free_vfs(struct ice_pf *pf)
 		}
 
 		/* clear malicious info since the VF is getting released */
-		list_del(&vf->mbx_info.list_entry);
+		if (!ice_is_feature_supported(pf, ICE_F_MBX_LIMIT))
+			list_del(&vf->mbx_info.list_entry);
 
 		mutex_unlock(&vf->cfg_lock);
 	}