i40e: Prevent deleting MAC address from VF when set by PF

BugLink: https://bugs.launchpad.net/bugs/1853881

[ Upstream commit 5907cf6c ]

To prevent VF from deleting MAC address that was assigned by the
PF we need to check for that scenario when we try to delete a MAC
address from a VF.
Signed-off-by: Patryk Małek <patryk.malek@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

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

@@ -1693,6 +1693,16 @@ static int i40e_vc_del_mac_addr_msg(struct i40e_vf *vf, u8 *msg, u16 msglen)
 			ret = I40E_ERR_INVALID_MAC_ADDR;
 			goto error_param;
 		}
+
+		if (vf->pf_set_mac &&
+		    ether_addr_equal(al->list[i].addr,
+				     vf->default_lan_addr.addr)) {
+			dev_err(&pf->pdev->dev,
+				"MAC addr %pM has been set by PF, cannot delete it for VF %d, reset VF to change MAC addr\n",
+				vf->default_lan_addr.addr, vf->vf_id);
+			ret = I40E_ERR_PARAM;
+			goto error_param;
+		}
 	}
 	vsi = pf->vsi[vf->lan_vsi_idx];