libbpf: Add "map_extra" as a per-map-type extra flag

This patch adds the libbpf infrastructure for supporting a
per-map-type "map_extra" field, whose definition will be
idiosyncratic depending on map type.

For example, for the bloom filter map, the lower 4 bits of
map_extra is used to denote the number of hash functions.

Please note that until libbpf 1.0 is here, the
"bpf_create_map_params" struct is used as a temporary
means for propagating the map_extra field to the kernel.

Signed-off-by: Joanne Koong <joannekoong@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20211027234504.30744-3-joannekoong@fb.com
This commit is contained in:
Joanne Koong
2021-10-27 16:45:01 -07:00
committed by Andrii Nakryiko
parent 11f873fd5b
commit 28c8a2c179
7 changed files with 91 additions and 9 deletions

View File

@@ -431,7 +431,7 @@ void bpf_gen__load_btf(struct bpf_gen *gen, const void *btf_raw_data,
}
void bpf_gen__map_create(struct bpf_gen *gen,
struct bpf_create_map_attr *map_attr, int map_idx)
struct bpf_create_map_params *map_attr, int map_idx)
{
int attr_size = offsetofend(union bpf_attr, btf_vmlinux_value_type_id);
bool close_inner_map_fd = false;
@@ -443,6 +443,7 @@ void bpf_gen__map_create(struct bpf_gen *gen,
attr.key_size = map_attr->key_size;
attr.value_size = map_attr->value_size;
attr.map_flags = map_attr->map_flags;
attr.map_extra = map_attr->map_extra;
memcpy(attr.map_name, map_attr->name,
min((unsigned)strlen(map_attr->name), BPF_OBJ_NAME_LEN - 1));
attr.numa_node = map_attr->numa_node;