bpf: offload: allow array map offload

The special handling of different map types is left to the driver.
Allow offload of array maps by simply adding it to accepted types.
For nfp we have to make sure array elements are not deleted.
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>

drivers/net/ethernet/netronome/nfp/bpf/offload.c

@@ -176,6 +176,8 @@ nfp_bpf_map_get_next_key(struct bpf_offloaded_map *offmap,
 static int
 nfp_bpf_map_delete_elem(struct bpf_offloaded_map *offmap, void *key)
 {
+	if (offmap->map.map_type == BPF_MAP_TYPE_ARRAY)
+		return -EINVAL;
 	return nfp_bpf_ctrl_del_entry(offmap, key);
 }
 

kernel/bpf/offload.c

@@ -299,7 +299,8 @@ struct bpf_map *bpf_map_offload_map_alloc(union bpf_attr *attr)
 
 	if (!capable(CAP_SYS_ADMIN))
 		return ERR_PTR(-EPERM);
-	if (attr->map_type != BPF_MAP_TYPE_HASH)
+	if (attr->map_type != BPF_MAP_TYPE_ARRAY &&
+	    attr->map_type != BPF_MAP_TYPE_HASH)
 		return ERR_PTR(-EINVAL);
 
 	offmap = kzalloc(sizeof(*offmap), GFP_USER);