docs/devel/ebpf_rss.rst: Format literals correctly

In rST markup, single backticks `like this` represent "interpreted
text", which can be handled as a bunch of different things if tagged
with a specific "role":
https://docutils.sourceforge.io/docs/ref/rst/restructuredtext.html#interpreted-text
(the most common one for us is "reference to a URL, which gets
hyperlinked").

The default "role" if none is specified is "title_reference",
intended for references to book or article titles, and it renders
into the HTML as <cite>...</cite> (usually comes out as italics).

To format a literal (generally rendered as fixed-width font),
double-backticks are required.

ebpf_rss.rst gets this wrong in a few places; correct them.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20210726142338.31872-4-peter.maydell@linaro.org
This commit is contained in:
Peter Maydell 2021-07-26 15:23:31 +01:00
parent d463f3c79a
commit f0d7b970ac

View File

@ -72,7 +72,7 @@ eBPF RSS implementation
eBPF RSS loading functionality located in ebpf/ebpf_rss.c and ebpf/ebpf_rss.h.
The `struct EBPFRSSContext` structure that holds 4 file descriptors:
The ``struct EBPFRSSContext`` structure that holds 4 file descriptors:
- ctx - pointer of the libbpf context.
- program_fd - file descriptor of the eBPF RSS program.
@ -80,20 +80,20 @@ The `struct EBPFRSSContext` structure that holds 4 file descriptors:
- map_toeplitz_key - file descriptor of the 'Toeplitz key' map. One element of the 40byte key prepared for the hashing algorithm.
- map_indirections_table - 128 elements of queue indexes.
`struct EBPFRSSConfig` fields:
``struct EBPFRSSConfig`` fields:
- redirect - "boolean" value, should the hash be calculated, on false - `default_queue` would be used as the final decision.
- redirect - "boolean" value, should the hash be calculated, on false - ``default_queue`` would be used as the final decision.
- populate_hash - for now, not used. eBPF RSS doesn't support hash reporting.
- hash_types - binary mask of different hash types. See `VIRTIO_NET_RSS_HASH_TYPE_*` defines. If for packet hash should not be calculated - `default_queue` would be used.
- hash_types - binary mask of different hash types. See ``VIRTIO_NET_RSS_HASH_TYPE_*`` defines. If for packet hash should not be calculated - ``default_queue`` would be used.
- indirections_len - length of the indirections table, maximum 128.
- default_queue - the queue index that used for packet that shouldn't be hashed. For some packets, the hash can't be calculated(g.e ARP).
Functions:
- `ebpf_rss_init()` - sets ctx to NULL, which indicates that EBPFRSSContext is not loaded.
- `ebpf_rss_load()` - creates 3 maps and loads eBPF program from the rss.bpf.skeleton.h. Returns 'true' on success. After that, program_fd can be used to set steering for TAP.
- `ebpf_rss_set_all()` - sets values for eBPF maps. `indirections_table` length is in EBPFRSSConfig. `toeplitz_key` is VIRTIO_NET_RSS_MAX_KEY_SIZE aka 40 bytes array.
- `ebpf_rss_unload()` - close all file descriptors and set ctx to NULL.
- ``ebpf_rss_init()`` - sets ctx to NULL, which indicates that EBPFRSSContext is not loaded.
- ``ebpf_rss_load()`` - creates 3 maps and loads eBPF program from the rss.bpf.skeleton.h. Returns 'true' on success. After that, program_fd can be used to set steering for TAP.
- ``ebpf_rss_set_all()`` - sets values for eBPF maps. ``indirections_table`` length is in EBPFRSSConfig. ``toeplitz_key`` is VIRTIO_NET_RSS_MAX_KEY_SIZE aka 40 bytes array.
- ``ebpf_rss_unload()`` - close all file descriptors and set ctx to NULL.
Simplified eBPF RSS workflow:
@ -122,4 +122,4 @@ Simplified eBPF RSS workflow:
NetClientState SetSteeringEBPF()
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
For now, `set_steering_ebpf()` method supported by Linux TAP NetClientState. The method requires an eBPF program file descriptor as an argument.
For now, ``set_steering_ebpf()`` method supported by Linux TAP NetClientState. The method requires an eBPF program file descriptor as an argument.