This patch adds support for the new BPF_CPU flag in bpftool, to enable
single-cpu updates of per-cpu maps. It can be combined with existing
flags; for example, to update the value for key 0 on CPU 9 only if it
doesn't already exist:
bpftool map update key 0 0 0 0 value 1 0 0 0 noexist cpu 9
Signed-off-by: Paul Chaignon <paul.chaignon@xxxxxxxxxx>
---
.../bpf/bpftool/Documentation/bpftool-map.rst | 13 ++--
tools/bpf/bpftool/bash-completion/bpftool | 2 +-
tools/bpf/bpftool/map.c | 70 ++++++++++++++-----
3 files changed, 61 insertions(+), 24 deletions(-)
diff --git a/tools/bpf/bpftool/Documentation/bpftool-map.rst b/tools/bpf/bpftool/Documentation/bpftool-map.rst
index cdeae8ae90ba..72aa9b72f08f 100644
--- a/tools/bpf/bpftool/Documentation/bpftool-map.rst
+++ b/tools/bpf/bpftool/Documentation/bpftool-map.rst
@@ -25,7 +25,7 @@ MAP COMMANDS
| **bpftool** **map create** *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE* \
| **entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**dev** *NAME*]
| **bpftool** **map dump** *MAP*
-| **bpftool** **map update** *MAP* [**key** *DATA*] [**value** *VALUE*] [*UPDATE_FLAGS*]
+| **bpftool** **map update** *MAP* [**key** *DATA*] [**value** *VALUE*] [*UPDATE_FLAGS*]...
| **bpftool** **map lookup** *MAP* [**key** *DATA*]
| **bpftool** **map getnext** *MAP* [**key** *DATA*]
| **bpftool** **map delete** *MAP* **key** *DATA*
@@ -43,7 +43,7 @@ MAP COMMANDS
| *DATA* := { [**hex**] *BYTES* }
| *PROG* := { **id** *PROG_ID* | **pinned** *FILE* | **tag** *PROG_TAG* | **name** *PROG_NAME* }
| *VALUE* := { *DATA* | *MAP* | *PROG* }
-| *UPDATE_FLAGS* := { **any** | **exist** | **noexist** }
+| *UPDATE_FLAGS* := { **any** | **exist** | **noexist** | **cpu** *CPU_ID* }
| *TYPE* := { **hash** | **array** | **prog_array** | **perf_event_array** | **percpu_hash**
| | **percpu_array** | **stack_trace** | **cgroup_array** | **lru_hash**
| | **lru_percpu_hash** | **lpm_trie** | **array_of_maps** | **hash_of_maps**
@@ -73,9 +73,12 @@ DESCRIPTION
**bpftool map update** *MAP* [**key** *DATA*] [**value** *VALUE*] [*UPDATE_FLAGS*]
Update map entry for a given *KEY*.
- *UPDATE_FLAGS* can be one of: **any** update existing entry
- or add if doesn't exit; **exist** update only if entry already
- exists; **noexist** update only if entry doesn't exist.
+ *UPDATE_FLAGS* can be: **any** update existing entry or add
+ if doesn't exit; **exist** update only if entry already
+ exists; **noexist** update only if entry doesn't exist;
+ **cpu** update only value for given *CPU_ID* in per-CPU map.
+ Only one of **any**, **exist**, and **noexist** can be
+ specified.
If the **hex** keyword is provided in front of the bytes
sequence, the bytes are parsed as hexadeximal values, even if
diff --git a/tools/bpf/bpftool/bash-completion/bpftool b/tools/bpf/bpftool/bash-completion/bpftool
index 754d8395e451..116bf3dffb47 100644
--- a/tools/bpf/bpftool/bash-completion/bpftool
+++ b/tools/bpf/bpftool/bash-completion/bpftool
@@ -689,7 +689,7 @@ _bpftool()
esac
_bpftool_once_attr 'key'
- local UPDATE_FLAGS='any exist noexist'
+ local UPDATE_FLAGS='any exist noexist cpu'
for (( idx=3; idx < ${#words[@]}-1; idx++ )); do
if [[ ${words[idx]} == 'value' ]]; then
# 'value' is present, but is not the last
diff --git a/tools/bpf/bpftool/map.c b/tools/bpf/bpftool/map.c
index c01f76fa6876..da1455f460b1 100644
--- a/tools/bpf/bpftool/map.c
+++ b/tools/bpf/bpftool/map.c
@@ -470,9 +470,10 @@ static void fill_per_cpu_value(struct bpf_map_info *info, void *value)
memcpy(value + i * step, value, info->value_size);
}
-static int parse_elem(char **argv, struct bpf_map_info *info,
- void *key, void *value, __u32 key_size, __u32 value_size,
- __u32 *flags, __u32 **value_fd)
+static int
+__parse_elem(char **argv, struct bpf_map_info *info, void *key, void *value,
+ __u32 key_size, __u32 value_size, __u64 *flags, __u32 **value_fd,
+ bool any_flag)
{
if (!*argv) {
if (!key && !value)
@@ -494,8 +495,8 @@ static int parse_elem(char **argv, struct bpf_map_info *info,
if (!argv)
return -1;
- return parse_elem(argv, info, NULL, value, key_size, value_size,
- flags, value_fd);
+ return __parse_elem(argv, info, NULL, value, key_size,
+ value_size, flags, value_fd, any_flag);
} else if (is_prefix(*argv, "value")) {
int fd;
@@ -556,30 +557,63 @@ static int parse_elem(char **argv, struct bpf_map_info *info,
fill_per_cpu_value(info, value);
}
- return parse_elem(argv, info, key, NULL, key_size, value_size,
- flags, NULL);
+ return __parse_elem(argv, info, key, NULL, key_size,
+ value_size, flags, NULL, any_flag);
} else if (is_prefix(*argv, "any") || is_prefix(*argv, "noexist") ||
is_prefix(*argv, "exist")) {
- if (!flags) {
+ if (any_flag || *flags & (BPF_NOEXIST | BPF_EXIST)) {
p_err("flags specified multiple times: %s", *argv);
return -1;
}
- if (is_prefix(*argv, "any"))
- *flags = BPF_ANY;
- else if (is_prefix(*argv, "noexist"))
- *flags = BPF_NOEXIST;
- else if (is_prefix(*argv, "exist"))
- *flags = BPF_EXIST;
+ if (is_prefix(*argv, "any")) {
+ *flags |= BPF_ANY;
+ any_flag = true;
+ } else if (is_prefix(*argv, "noexist")) {
+ *flags |= BPF_NOEXIST;
+ } else if (is_prefix(*argv, "exist")) {
+ *flags |= BPF_EXIST;
+ }
+
+ return __parse_elem(argv + 1, info, key, value, key_size,
+ value_size, flags, value_fd, any_flag);
+ } else if (is_prefix(*argv, "cpu")) {
+ unsigned long long cpuid;
+ char *endptr;
+
+ if (*flags & BPF_CPU) {
+ p_err("flags specified multiple times: %s", *argv);
+ return -1;
+ }
- return parse_elem(argv + 1, info, key, value, key_size,
- value_size, NULL, value_fd);
+ cpuid = strtoull(*(argv + 1), &endptr, 0);
+ if (*endptr) {
+ p_err("can't parse CPU id %s", *(argv + 1));
+ return -1;
+ }
+ if (cpuid >= get_possible_cpus()) {
+ p_err("incorrect value for CPU id");
+ return -1;
+ }
+
+ *flags |= (cpuid << 32) | BPF_CPU;
+
+ return __parse_elem(argv + 2, info, key, value, key_size,
+ value_size, flags, value_fd, any_flag);
}
p_err("expected key or value, got: %s", *argv);
return -1;
}
+static int
+parse_elem(char **argv, struct bpf_map_info *info, void *key, void *value,
+ __u32 key_size, __u32 value_size, __u64 *flags, __u32 **value_fd)
+{
+ return __parse_elem(argv, info, key, value, key_size, value_size,
+ flags, value_fd, false);
+}
+
static void show_map_header_json(struct bpf_map_info *info, json_writer_t *wtr)
{
jsonw_uint_field(wtr, "id", info->id);
@@ -1114,7 +1148,7 @@ static int do_update(int argc, char **argv)
struct bpf_map_info info = {};
__u32 len = sizeof(info);
__u32 *value_fd = NULL;
- __u32 flags = BPF_ANY;
+ __u64 flags = BPF_ANY;
void *key, *value;
int fd, err;
@@ -1558,7 +1592,7 @@ static int do_help(int argc, char **argv)
" DATA := { [hex] BYTES }\n"
" " HELP_SPEC_PROGRAM "\n"
" VALUE := { DATA | MAP | PROG }\n"
- " UPDATE_FLAGS := { any | exist | noexist }\n"
+ " UPDATE_FLAGS := { any | exist | noexist | cpu CPU_ID }\n"
" TYPE := { hash | array | prog_array | perf_event_array | percpu_hash |\n"
" percpu_array | stack_trace | cgroup_array | lru_hash |\n"
" lru_percpu_hash | lpm_trie | array_of_maps | hash_of_maps |\n"
--
2.24.0
