xiaomi-sm8450/android_kernel_xiaomi_sm8450
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

tools: bpftool: Add "inner_map" to "bpftool map create" outer maps

Browse Source 
There is no support for creating maps of types array-of-map or
hash-of-map in bpftool. This is because the kernel needs an inner_map_fd
to collect metadata on the inner maps to be supported by the new map,
but bpftool does not provide a way to pass this file descriptor.

Add a new optional "inner_map" keyword that can be used to pass a
reference to a map, retrieve a fd to that map, and pass it as the
inner_map_fd.

Add related documentation and bash completion. Note that we can
reference the inner map by its name, meaning we can have several times
the keyword "name" with different meanings (mandatory outer map name,
and possibly a name to use to find the inner_map_fd). The bash
completion will offer it just once, and will not suggest "name" on the
following command:

    # bpftool map create /sys/fs/bpf/my_outer_map type hash_of_maps \
        inner_map name my_inner_map [TAB]

Fixing that specific case seems too convoluted. Completion will work as
expected, however, if the outer map name comes first and the "inner_map
name ..." is passed second.

Signed-off-by: Quentin Monnet <quentin@isovalent.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/20200910102652.10509-4-quentin@isovalent.com
This commit is contained in:
Quentin Monnet
2020-09-10 11:26:52 +01:00
committed by Alexei Starovoitov
parent 86233ce35e
commit e3b9626f09
3 changed files with 62 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

10
tools/bpf/bpftool/Documentation/bpftool-map.rst
View File

@@ -23,7 +23,8 @@ MAP COMMANDS
| **bpftool** **map** { **show** | **list** } [*MAP*]
| **bpftool** **map create** *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE* \
| **entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**dev** *NAME*]
| **entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**inner_map** *MAP*] \
| [**dev** *NAME*]
| **bpftool** **map dump** *MAP*
| **bpftool** **map update** *MAP* [**key** *DATA*] [**value** *VALUE*] [*UPDATE_FLAGS*]
| **bpftool** **map lookup** *MAP* [**key** *DATA*]
@@ -67,7 +68,7 @@ DESCRIPTION
maps. On such kernels bpftool will automatically emit this
information as well.
**bpftool map create** *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE* **entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**dev** *NAME*]
**bpftool map create** *FILE* **type** *TYPE* **key** *KEY_SIZE* **value** *VALUE_SIZE* **entries** *MAX_ENTRIES* **name** *NAME* [**flags** *FLAGS*] [**inner_map** *MAP*] [**dev** *NAME*]
Create a new map with given parameters and pin it to *bpffs*
as *FILE*.
@@ -75,6 +76,11 @@ DESCRIPTION
desired flags, e.g. 1024 for **BPF_F_MMAPABLE** (see bpf.h
UAPI header for existing flags).
To create maps of type array-of-maps or hash-of-maps, the
**inner_map** keyword must be used to pass an inner map. The
kernel needs it to collect metadata related to the inner maps
that the new map will work with.
Keyword **dev** expects a network interface name, and is used
to request hardware offload for the map.