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
diff --git a/src/bpf.c b/src/bpf.c
index 7d1741c..fe4b6eb 100644
--- a/src/bpf.c
+++ b/src/bpf.c
@@ -77,7 +77,7 @@
return fd;
}
-int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr)
+int libbpf__bpf_create_map_xattr(const struct bpf_create_map_params *create_attr)
{
union bpf_attr attr;
int fd;
@@ -102,11 +102,36 @@
create_attr->btf_vmlinux_value_type_id;
else
attr.inner_map_fd = create_attr->inner_map_fd;
+ attr.map_extra = create_attr->map_extra;
fd = sys_bpf(BPF_MAP_CREATE, &attr, sizeof(attr));
return libbpf_err_errno(fd);
}
+int bpf_create_map_xattr(const struct bpf_create_map_attr *create_attr)
+{
+ struct bpf_create_map_params p = {};
+
+ p.map_type = create_attr->map_type;
+ p.key_size = create_attr->key_size;
+ p.value_size = create_attr->value_size;
+ p.max_entries = create_attr->max_entries;
+ p.map_flags = create_attr->map_flags;
+ p.name = create_attr->name;
+ p.numa_node = create_attr->numa_node;
+ p.btf_fd = create_attr->btf_fd;
+ p.btf_key_type_id = create_attr->btf_key_type_id;
+ p.btf_value_type_id = create_attr->btf_value_type_id;
+ p.map_ifindex = create_attr->map_ifindex;
+ if (p.map_type == BPF_MAP_TYPE_STRUCT_OPS)
+ p.btf_vmlinux_value_type_id =
+ create_attr->btf_vmlinux_value_type_id;
+ else
+ p.inner_map_fd = create_attr->inner_map_fd;
+
+ return libbpf__bpf_create_map_xattr(&p);
+}
+
int bpf_create_map_node(enum bpf_map_type map_type, const char *name,
int key_size, int value_size, int max_entries,
__u32 map_flags, int node)
diff --git a/src/bpf_gen_internal.h b/src/bpf_gen_internal.h
index 70eccbf..b8d41d6 100644
--- a/src/bpf_gen_internal.h
+++ b/src/bpf_gen_internal.h
@@ -43,7 +43,7 @@
int bpf_gen__finish(struct bpf_gen *gen);
void bpf_gen__free(struct bpf_gen *gen);
void bpf_gen__load_btf(struct bpf_gen *gen, const void *raw_data, __u32 raw_size);
-void bpf_gen__map_create(struct bpf_gen *gen, struct bpf_create_map_attr *map_attr, int map_idx);
+void bpf_gen__map_create(struct bpf_gen *gen, struct bpf_create_map_params *map_attr, int map_idx);
struct bpf_prog_load_params;
void bpf_gen__prog_load(struct bpf_gen *gen, struct bpf_prog_load_params *load_attr, int prog_idx);
void bpf_gen__map_update_elem(struct bpf_gen *gen, int map_idx, void *value, __u32 value_size);
diff --git a/src/gen_loader.c b/src/gen_loader.c
index 937bfc7..e552484 100644
--- a/src/gen_loader.c
+++ b/src/gen_loader.c
@@ -431,7 +431,7 @@
}
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 @@
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;
diff --git a/src/libbpf.c b/src/libbpf.c
index b6e0e86..1883af0 100644
--- a/src/libbpf.c
+++ b/src/libbpf.c
@@ -400,6 +400,7 @@
char *pin_path;
bool pinned;
bool reused;
+ __u64 map_extra;
};
enum extern_type {
@@ -2324,6 +2325,13 @@
}
map_def->pinning = val;
map_def->parts |= MAP_DEF_PINNING;
+ } else if (strcmp(name, "map_extra") == 0) {
+ __u32 map_extra;
+
+ if (!get_map_field_int(map_name, btf, m, &map_extra))
+ return -EINVAL;
+ map_def->map_extra = map_extra;
+ map_def->parts |= MAP_DEF_MAP_EXTRA;
} else {
if (strict) {
pr_warn("map '%s': unknown field '%s'.\n", map_name, name);
@@ -2348,6 +2356,7 @@
map->def.value_size = def->value_size;
map->def.max_entries = def->max_entries;
map->def.map_flags = def->map_flags;
+ map->map_extra = def->map_extra;
map->numa_node = def->numa_node;
map->btf_key_type_id = def->key_type_id;
@@ -2371,7 +2380,10 @@
if (def->parts & MAP_DEF_MAX_ENTRIES)
pr_debug("map '%s': found max_entries = %u.\n", map->name, def->max_entries);
if (def->parts & MAP_DEF_MAP_FLAGS)
- pr_debug("map '%s': found map_flags = %u.\n", map->name, def->map_flags);
+ pr_debug("map '%s': found map_flags = 0x%x.\n", map->name, def->map_flags);
+ if (def->parts & MAP_DEF_MAP_EXTRA)
+ pr_debug("map '%s': found map_extra = 0x%llx.\n", map->name,
+ (unsigned long long)def->map_extra);
if (def->parts & MAP_DEF_PINNING)
pr_debug("map '%s': found pinning = %u.\n", map->name, def->pinning);
if (def->parts & MAP_DEF_NUMA_NODE)
@@ -4210,6 +4222,7 @@
map->btf_key_type_id = info.btf_key_type_id;
map->btf_value_type_id = info.btf_value_type_id;
map->reused = true;
+ map->map_extra = info.map_extra;
return 0;
@@ -4724,7 +4737,8 @@
map_info.key_size == map->def.key_size &&
map_info.value_size == map->def.value_size &&
map_info.max_entries == map->def.max_entries &&
- map_info.map_flags == map->def.map_flags);
+ map_info.map_flags == map->def.map_flags &&
+ map_info.map_extra == map->map_extra);
}
static int
@@ -4807,7 +4821,7 @@
static int bpf_object__create_map(struct bpf_object *obj, struct bpf_map *map, bool is_inner)
{
- struct bpf_create_map_attr create_attr;
+ struct bpf_create_map_params create_attr;
struct bpf_map_def *def = &map->def;
int err = 0;
@@ -4821,6 +4835,7 @@
create_attr.key_size = def->key_size;
create_attr.value_size = def->value_size;
create_attr.numa_node = map->numa_node;
+ create_attr.map_extra = map->map_extra;
if (def->type == BPF_MAP_TYPE_PERF_EVENT_ARRAY && !def->max_entries) {
int nr_cpus;
@@ -4895,7 +4910,7 @@
*/
map->fd = 0;
} else {
- map->fd = bpf_create_map_xattr(&create_attr);
+ map->fd = libbpf__bpf_create_map_xattr(&create_attr);
}
if (map->fd < 0 && (create_attr.btf_key_type_id ||
create_attr.btf_value_type_id)) {
@@ -4910,7 +4925,7 @@
create_attr.btf_value_type_id = 0;
map->btf_key_type_id = 0;
map->btf_value_type_id = 0;
- map->fd = bpf_create_map_xattr(&create_attr);
+ map->fd = libbpf__bpf_create_map_xattr(&create_attr);
}
err = map->fd < 0 ? -errno : 0;
@@ -8881,6 +8896,19 @@
return 0;
}
+__u64 bpf_map__map_extra(const struct bpf_map *map)
+{
+ return map->map_extra;
+}
+
+int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra)
+{
+ if (map->fd >= 0)
+ return libbpf_err(-EBUSY);
+ map->map_extra = map_extra;
+ return 0;
+}
+
__u32 bpf_map__numa_node(const struct bpf_map *map)
{
return map->numa_node;
diff --git a/src/libbpf.h b/src/libbpf.h
index defabdb..9de0f29 100644
--- a/src/libbpf.h
+++ b/src/libbpf.h
@@ -600,6 +600,9 @@
/* get/set map if_index */
LIBBPF_API __u32 bpf_map__ifindex(const struct bpf_map *map);
LIBBPF_API int bpf_map__set_ifindex(struct bpf_map *map, __u32 ifindex);
+/* get/set map map_extra flags */
+LIBBPF_API __u64 bpf_map__map_extra(const struct bpf_map *map);
+LIBBPF_API int bpf_map__set_map_extra(struct bpf_map *map, __u64 map_extra);
typedef void (*bpf_map_clear_priv_t)(struct bpf_map *, void *);
LIBBPF_API int bpf_map__set_priv(struct bpf_map *map, void *priv,
diff --git a/src/libbpf.map b/src/libbpf.map
index 15239c0..43580eb 100644
--- a/src/libbpf.map
+++ b/src/libbpf.map
@@ -389,6 +389,8 @@
LIBBPF_0.6.0 {
global:
+ bpf_map__map_extra;
+ bpf_map__set_map_extra;
bpf_object__next_map;
bpf_object__next_program;
bpf_object__prev_map;
diff --git a/src/libbpf_internal.h b/src/libbpf_internal.h
index 13bc795..a6dd7e2 100644
--- a/src/libbpf_internal.h
+++ b/src/libbpf_internal.h
@@ -193,8 +193,9 @@
MAP_DEF_NUMA_NODE = 0x080,
MAP_DEF_PINNING = 0x100,
MAP_DEF_INNER_MAP = 0x200,
+ MAP_DEF_MAP_EXTRA = 0x400,
- MAP_DEF_ALL = 0x3ff, /* combination of all above */
+ MAP_DEF_ALL = 0x7ff, /* combination of all above */
};
struct btf_map_def {
@@ -208,6 +209,7 @@
__u32 map_flags;
__u32 numa_node;
__u32 pinning;
+ __u64 map_extra;
};
int parse_btf_map_def(const char *map_name, struct btf *btf,
@@ -303,6 +305,27 @@
int libbpf__bpf_prog_load(const struct bpf_prog_load_params *load_attr);
+struct bpf_create_map_params {
+ const char *name;
+ enum bpf_map_type map_type;
+ __u32 map_flags;
+ __u32 key_size;
+ __u32 value_size;
+ __u32 max_entries;
+ __u32 numa_node;
+ __u32 btf_fd;
+ __u32 btf_key_type_id;
+ __u32 btf_value_type_id;
+ __u32 map_ifindex;
+ union {
+ __u32 inner_map_fd;
+ __u32 btf_vmlinux_value_type_id;
+ };
+ __u64 map_extra;
+};
+
+int libbpf__bpf_create_map_xattr(const struct bpf_create_map_params *create_attr);
+
struct btf *btf_get_from_fd(int btf_fd, struct btf *base_btf);
void btf_get_kernel_prefix_kind(enum bpf_attach_type attach_type,
const char **prefix, int *kind);
