selftsets/bpf: Retry map update for non-preallocated per-cpu map

BPF CI failed due to map_percpu_stats_percpu_hash from time to time [1].
It seems that the failure reason is per-cpu bpf memory allocator may not
be able to allocate per-cpu pointer successfully and it can not refill
free llist timely, and bpf_map_update_elem() will return -ENOMEM.

So mitigate the problem by retrying the update operation for
non-preallocated per-cpu map.

[1]: https://github.com/kernel-patches/bpf/actions/runs/6713177520/job/18244865326?pr=5909

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231101032455.3808547-4-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: Use value with enough-size when updating per-cpu map

When updating per-cpu map in map_percpu_stats test, patch_map_thread()
only passes 4-bytes-sized value to bpf_map_update_elem(). The expected
size of the value is 8 * num_possible_cpus(), so fix it by passing a
value with enough-size for per-cpu map update.

Signed-off-by: Hou Tao <houtao1@huawei.com>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20231101032455.3808547-2-houtao@huaweicloud.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: fix test_maps' use of bpf_map_create_opts

Use LIBBPF_OPTS() macro to properly initialize bpf_map_create_opts in
test_maps' tests.

Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Link: https://lore.kernel.org/r/20231029011509.2479232-1-andrii@kernel.org
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

selftests/bpf: test map percpu stats

Add a new map test, map_percpu_stats.c, which is checking the correctness of
map's percpu elements counters. For supported maps the test upserts a number
of elements, checks the correctness of the counters, then deletes all the
elements and checks again that the counters sum drops down to zero.

The following map types are tested:

* BPF_MAP_TYPE_HASH, BPF_F_NO_PREALLOC
* BPF_MAP_TYPE_PERCPU_HASH, BPF_F_NO_PREALLOC
* BPF_MAP_TYPE_HASH,
* BPF_MAP_TYPE_PERCPU_HASH,
* BPF_MAP_TYPE_LRU_HASH
* BPF_MAP_TYPE_LRU_PERCPU_HASH
* BPF_MAP_TYPE_LRU_HASH, BPF_F_NO_COMMON_LRU
* BPF_MAP_TYPE_LRU_PERCPU_HASH, BPF_F_NO_COMMON_LRU
* BPF_MAP_TYPE_HASH_OF_MAPS

Signed-off-by: Anton Protopopov <aspsk@isovalent.com>
Acked-by: Hou Tao <houtao1@huawei.com>
Link: https://lore.kernel.org/r/20230706133932.45883-6-aspsk@isovalent.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>