[next PATCH 11/11] ixgbe: Clean stale VLANs when changing port vlan or resetting

[Alexander Duyck <aduyck@mirantis.com>]

This patch guarantees that the VFs do not have access to VLANs that they
were not supposed to.  What this patch does is add code so that we delete
the previous port VLAN after adding a new one, and if we reset the VF we
clear all of the filters associated with it.

Previously the code was leaving all previous VLANs mapped to the VF and
they didn't get deleted unless the VF specifically requested it or if the
PF itself was reset.

Signed-off-by: Alexander Duyck <aduyck@mirantis.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c |   77 ++++++++++++++++++++++--
 1 file changed, 72 insertions(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c
index 03d4e5c9d71d..eeff3d075bf8 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_sriov.c
@@ -455,10 +455,6 @@ static int ixgbe_set_vf_vlan(struct ixgbe_adapter *adapter, int add, int vid,
 	struct ixgbe_hw *hw = &adapter->hw;
 	int err;
 
-	/* VLAN 0 is a special case, don't allow it to be removed */
-	if (!vid && !add)
-		return 0;
-
 	/* If VLAN overlaps with one the PF is currently monitoring make
 	 * sure that we are able to allocate a VLVF entry.  This may be
 	 * redundant but it guarantees PF will maintain visibility to
@@ -589,13 +585,75 @@ static void ixgbe_clear_vmvir(struct ixgbe_adapter *adapter, u32 vf)
 
 	IXGBE_WRITE_REG(hw, IXGBE_VMVIR(vf), 0);
 }
+
+static void ixgbe_clear_vf_vlans(struct ixgbe_adapter *adapter, u32 vf)
+{
+	struct ixgbe_hw *hw = &adapter->hw;
+	u32 i;
+
+	/* post increment loop, covers VLVF_ENTRIES - 1 to 0 */
+	for (i = IXGBE_VLVF_ENTRIES; i--;) {
+		u32 word = IXGBE_VLVFB(i * 2 + vf / 32);
+		u32 bits[2], vlvfb, vid, vfta, vlvf;
+		u32 mask = 1 << (vf / 32);
+
+		vlvfb = IXGBE_READ_REG(hw, word);
+
+		/* if our bit isn't set we can skip it */
+		if (!(vlvfb & mask))
+			continue;
+
+		/* clear our bit from vlvfb */
+		vlvfb ^= mask;
+
+		/* create 64b mask to chedk to see if we should clear VLVF */
+		bits[word % 2] = vlvfb;
+		bits[(word % 2) ^ 1] = IXGBE_READ_REG(hw, word ^ 1);
+
+		/* if promisc is enabled, PF will be present, leave VFTA */
+		if (adapter->flags2 & IXGBE_FLAG2_VLAN_PROMISC) {
+			bits[VMDQ_P(0) / 32] &= ~(1 << (VMDQ_P(0) % 32));
+
+			if (bits[0] || bits[1])
+				goto update_vlvfb;
+			goto update_vlvf;
+		}
+
+		/* if other pools are present, just remove ourselves */
+		if (bits[0] || bits[1])
+			goto update_vlvfb;
+
+		/* if we cannot determine VLAN just remove ourselves */
+		vlvf = IXGBE_READ_REG(hw, IXGBE_VLVF(i));
+		if (!vlvf)
+			goto update_vlvfb;
+
+		vid = vlvf & VLAN_VID_MASK;
+		mask = 1 << (vid % 32);
+
+		/* clear bit from VFTA */
+		vfta = IXGBE_READ_REG(hw, IXGBE_VFTA(vid / 32));
+		if (vfta & mask)
+			IXGBE_WRITE_REG(hw, IXGBE_VFTA(vid / 32), vfta ^ mask);
+update_vlvf:
+		/* clear POOL selection enable */
+		IXGBE_WRITE_REG(hw, IXGBE_VLVF(i), 0);
+update_vlvfb:
+		/* clear pool bits */
+		IXGBE_WRITE_REG(hw, IXGBE_VLVFB(word), vlvfb);
+	}
+}
+
 static inline void ixgbe_vf_reset_event(struct ixgbe_adapter *adapter, u32 vf)
 {
 	struct ixgbe_hw *hw = &adapter->hw;
 	struct vf_data_storage *vfinfo = &adapter->vfinfo[vf];
 	u8 num_tcs = netdev_get_num_tc(adapter->netdev);
 
-	/* add PF assigned VLAN or VLAN 0 */
+	/* remove VLAN filters beloning to this VF */
+	ixgbe_clear_vf_vlans(adapter, vf);
+
+	/* add back PF assigned VLAN or VLAN 0 */
 	ixgbe_set_vf_vlan(adapter, true, vfinfo->pf_vlan, vf);
 
 	/* reset offloads to defaults */
@@ -858,6 +916,10 @@ static int ixgbe_set_vf_vlan_msg(struct ixgbe_adapter *adapter,
 		return -1;
 	}
 
+	/* VLAN 0 is a special case, don't allow it to be removed */
+	if (!vid && !add)
+		return 0;
+
 	err = ixgbe_set_vf_vlan(adapter, add, vid, vf);
 	if (err)
 		return err;
@@ -1251,6 +1313,9 @@ static int ixgbe_enable_port_vlan(struct ixgbe_adapter *adapter, int vf,
 	if (err)
 		goto out;
 
+	/* Revoke tagless access via VLAN 0 */
+	ixgbe_set_vf_vlan(adapter, false, 0, vf);
+
 	ixgbe_set_vmvir(adapter, vlan, qos, vf);
 	ixgbe_set_vmolr(hw, vf, false);
 	if (adapter->vfinfo[vf].spoofchk_enabled)
@@ -1284,6 +1349,8 @@ static int ixgbe_disable_port_vlan(struct ixgbe_adapter *adapter, int vf)
 
 	err = ixgbe_set_vf_vlan(adapter, false,
 				adapter->vfinfo[vf].pf_vlan, vf);
+	/* Restore tagless access via VLAN 0 */
+	ixgbe_set_vf_vlan(adapter, true, 0, vf);
 	ixgbe_clear_vmvir(adapter, vf);
 	ixgbe_set_vmolr(hw, vf, true);
 	hw->mac.ops.set_vlan_anti_spoofing(hw, false, vf);