size - 1);
 }
 
+#define LAST_ETH_FIELD vlan_tag
+#define LAST_IB_FIELD sl
+#define LAST_IPV4_FIELD dst_ip
+#define LAST_IPV6_FIELD dst_ip
+#define LAST_TCP_UDP_FIELD src_port
+
+/* Field is the last supported field */
+#define FIELDS_NOT_SUPPORTED(filter, field)\
+       memchr_inv((void *)&filter.field  +\
+                  sizeof(filter.field), 0,\
+                  sizeof(filter) -\
+                  offsetof(typeof(filter), field) -\
+                  sizeof(filter.field))
+
 static int parse_flow_attr(u32 *match_c, u32 *match_v,
                           const union ib_flow_spec *ib_spec)
 {
                                             outer_headers);
        switch (ib_spec->type) {
        case IB_FLOW_SPEC_ETH:
-               if (ib_spec->size != sizeof(ib_spec->eth))
-                       return -EINVAL;
+               if (FIELDS_NOT_SUPPORTED(ib_spec->eth.mask, LAST_ETH_FIELD))
+                       return -ENOTSUPP;
 
                ether_addr_copy(MLX5_ADDR_OF(fte_match_set_lyr_2_4, outer_headers_c,
                                             dmac_47_16),
                         ethertype, ntohs(ib_spec->eth.val.ether_type));
                break;
        case IB_FLOW_SPEC_IPV4:
-               if (ib_spec->size != sizeof(ib_spec->ipv4))
-                       return -EINVAL;
+               if (FIELDS_NOT_SUPPORTED(ib_spec->ipv4.mask, LAST_IPV4_FIELD))
+                       return -ENOTSUPP;
 
                MLX5_SET(fte_match_set_lyr_2_4, outer_headers_c,
                         ethertype, 0xffff);
                       sizeof(ib_spec->ipv4.val.dst_ip));
                break;
        case IB_FLOW_SPEC_IPV6:
-               if (ib_spec->size != sizeof(ib_spec->ipv6))
-                       return -EINVAL;
+               if (FIELDS_NOT_SUPPORTED(ib_spec->ipv6.mask, LAST_IPV6_FIELD))
+                       return -ENOTSUPP;
 
                MLX5_SET(fte_match_set_lyr_2_4, outer_headers_c,
                         ethertype, 0xffff);
                       sizeof(ib_spec->ipv6.val.dst_ip));
                break;
        case IB_FLOW_SPEC_TCP:
-               if (ib_spec->size != sizeof(ib_spec->tcp_udp))
-                       return -EINVAL;
+               if (FIELDS_NOT_SUPPORTED(ib_spec->tcp_udp.mask,
+                                        LAST_TCP_UDP_FIELD))
+                       return -ENOTSUPP;
 
                MLX5_SET(fte_match_set_lyr_2_4, outer_headers_c, ip_protocol,
                         0xff);
                         ntohs(ib_spec->tcp_udp.val.dst_port));
                break;
        case IB_FLOW_SPEC_UDP:
-               if (ib_spec->size != sizeof(ib_spec->tcp_udp))
-                       return -EINVAL;
+               if (FIELDS_NOT_SUPPORTED(ib_spec->tcp_udp.mask,
+                                        LAST_TCP_UDP_FIELD))
+                       return -ENOTSUPP;
 
                MLX5_SET(fte_match_set_lyr_2_4, outer_headers_c, ip_protocol,
                         0xff);