i40e: Fix adding unsupported cloud filters

If a VF tries to add unsupported cloud filter through virtchnl
then i40e_add_del_cloud_filter(_big_buf) returns -ENOTSUPP but
this error code is stored in 'ret' instead of 'aq_ret' that
is used as error code sent back to VF. In this scenario where
one of the mentioned functions fails the value of 'aq_ret'
is zero so the VF will incorrectly receive a 'success'.

Use 'aq_ret' to store return value and remove 'ret' local
variable. Additionally fix the issue when filter allocation
fails, in this case no notification is sent back to the VF.

Fixes: e284fc28 ("i40e: Add and delete cloud filter")
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Ivan Vecera <ivecera@redhat.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Link: https://lore.kernel.org/r/20231121211338.3348677-1-anthony.l.nguyen@intel.comSigned-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/intel/i40e/i40e_virtchnl_pf.c

@@ -3844,7 +3844,7 @@ static int i40e_vc_add_cloud_filter(struct i40e_vf *vf, u8 *msg)
 	struct i40e_pf *pf = vf->pf;
 	struct i40e_vsi *vsi = NULL;
 	int aq_ret = 0;
-	int i, ret;
+	int i;
 
 	if (!i40e_sync_vf_state(vf, I40E_VF_STATE_ACTIVE)) {
 		aq_ret = -EINVAL;
@@ -3868,8 +3868,10 @@ static int i40e_vc_add_cloud_filter(struct i40e_vf *vf, u8 *msg)
 	}
 
 	cfilter = kzalloc(sizeof(*cfilter), GFP_KERNEL);
-	if (!cfilter)
-		return -ENOMEM;
+	if (!cfilter) {
+		aq_ret = -ENOMEM;
+		goto err_out;
+	}
 
 	/* parse destination mac address */
 	for (i = 0; i < ETH_ALEN; i++)
@@ -3917,13 +3919,13 @@ static int i40e_vc_add_cloud_filter(struct i40e_vf *vf, u8 *msg)
 
 	/* Adding cloud filter programmed as TC filter */
 	if (tcf.dst_port)
-		ret = i40e_add_del_cloud_filter_big_buf(vsi, cfilter, true);
+		aq_ret = i40e_add_del_cloud_filter_big_buf(vsi, cfilter, true);
 	else
-		ret = i40e_add_del_cloud_filter(vsi, cfilter, true);
-	if (ret) {
+		aq_ret = i40e_add_del_cloud_filter(vsi, cfilter, true);
+	if (aq_ret) {
 		dev_err(&pf->pdev->dev,
 			"VF %d: Failed to add cloud filter, err %pe aq_err %s\n",
-			vf->vf_id, ERR_PTR(ret),
+			vf->vf_id, ERR_PTR(aq_ret),
 			i40e_aq_str(&pf->hw, pf->hw.aq.asq_last_status));
 		goto err_free;
 	}