linux.git/Documentation/bpf/standardization, branch v6.10

bpf, docs: Fix the description of 'src' in ALU instructions

2024-05-15T16:34:54+00:00

An ALU instruction's source operand can be the value in the source
register or the 32-bit immediate value encoded in the instruction. This
is controlled by the 's' bit of the 'opcode'.

The current description explicitly uses the phrase 'value of the source
register' when defining the meaning of 'src'.

Change the description to use 'source operand' in place of 'value of the
source register'.

Signed-off-by: Puranjay Mohan 
Acked-by: Dave Thaler 
Link: https://lore.kernel.org/r/20240514130303.113607-1-puranjay@kernel.org
Signed-off-by: Alexei Starovoitov

bpf, docs: Clarify PC use in instruction-set.rst

2024-04-29T09:54:42+00:00

This patch elaborates on the use of PC by expanding the PC acronym,
explaining the units, and the relative position to which the offset
applies.

Signed-off-by: Dave Thaler 
Signed-off-by: Daniel Borkmann 
Reviewed-by: David Vernet 
Link: https://lore.kernel.org/bpf/20240426231126.5130-1-dthaler1968@gmail.com

bpf, docs: Add introduction for use in the ISA Internet Draft

2024-04-26T02:15:21+00:00

The proposed intro paragraph text is derived from the first paragraph
of the IETF BPF WG charter at https://datatracker.ietf.org/wg/bpf/about/

Signed-off-by: Dave Thaler 
Acked-by: David Vernet 
Link: https://lore.kernel.org/r/20240422190942.24658-1-dthaler1968@gmail.com
Signed-off-by: Alexei Starovoitov

bpf, docs: Fix formatting nit in instruction-set.rst

2024-04-21T17:09:12+00:00

Other places that had pseudocode were prefixed with ::
so as to appear in a literal block, but one place was inconsistent.
This patch fixes that inconsistency.

Signed-off-by: Dave Thaler 
Acked-by: David Vernet 
Link: https://lore.kernel.org/r/20240419213826.7301-1-dthaler1968@gmail.com
Signed-off-by: Alexei Starovoitov

bpf, docs: Clarify helper ID and pointer terms in instruction-set.rst

2024-04-21T17:08:56+00:00

Per IETF 119 meeting discussion and mailing list discussion at
https://mailarchive.ietf.org/arch/msg/bpf/2JwWQwFdOeMGv0VTbD0CKWwAOEA/
the following changes are made.

First, say call by "static ID" rather than call by "address"

Second, change "pointer" to "address"

Signed-off-by: Dave Thaler 
Acked-by: David Vernet 
Link: https://lore.kernel.org/r/20240419203617.6850-1-dthaler1968@gmail.com
Signed-off-by: Alexei Starovoitov

bpf, docs: Editorial nits in instruction-set.rst

2024-04-05T17:42:30+00:00

This patch addresses a number of editorial nits including
spelling, punctuation, grammar, and wording consistency issues
in instruction-set.rst.

Signed-off-by: Dave Thaler 
Acked-by: David Vernet 
Link: https://lore.kernel.org/r/20240405155245.3618-1-dthaler1968@gmail.com
Signed-off-by: Alexei Starovoitov

bpf, docs: Rename legacy conformance group to packet

2024-03-04T13:31:06+00:00

There could be other legacy conformance groups in the future,
so use a more descriptive name.  The status of the conformance
group in the IANA registry is what designates it as legacy,
not the name of the group.

Signed-off-by: Dave Thaler 
Link: https://lore.kernel.org/r/20240302012229.16452-1-dthaler1968@gmail.com
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Daniel Borkmann

bpf, docs: Use IETF format for field definitions in instruction-set.rst

2024-03-03T05:40:14+00:00

In preparation for publication as an IETF RFC, the WG chairs asked me
to convert the document to use IETF packet format for field layout, so
this patch attempts to make it consistent with other IETF documents.

Some fields that are not byte aligned were previously inconsistent
in how values were defined.  Some were defined as the value of the
byte containing the field (like 0x20 for a field holding the high
four bits of the byte), and others were defined as the value of the
field itself (like 0x2).  This PR makes them be consistent in using
just the values of the field itself, which is IETF convention.

As a result, some of the defines that used BPF_* would no longer
match the value in the spec, and so this patch also drops the BPF_*
prefix to avoid confusion with the defines that are the full-byte
equivalent values.  For consistency, BPF_* is then dropped from
other fields too.  BPF_ is thus the Linux implementation-specific
define for  as it appears in the BPF ISA specification.

The syntax BPF_ADD | BPF_X | BPF_ALU only worked for full-byte
values so the convention {ADD, X, ALU} is proposed for referring
to field values instead.

Also replace the redundant "LSB bits" with "least significant bits".

A preview of what the resulting Internet Draft would look like can
be seen at:
https://htmlpreview.github.io/?https://raw.githubusercontent.com/dthaler/ebp
f-docs-1/format/draft-ietf-bpf-isa.html

v1->v2: Fix sphinx issue as recommended by David Vernet

Signed-off-by: Dave Thaler 
Acked-by: David Vernet 
Link: https://lore.kernel.org/r/20240301222337.15931-1-dthaler1968@gmail.com
Signed-off-by: Alexei Starovoitov

bpf, docs: specify which BPF_ABS and BPF_IND fields were zero

2024-02-22T17:11:49+00:00

Specifying which fields were unused allows IANA to only list as deprecated
instructions that were actually used, leaving the rest as unassigned and
possibly available for future use for something else.

Signed-off-by: Dave Thaler 
Acked-by: David Vernet 
Link: https://lore.kernel.org/r/20240221175419.16843-1-dthaler1968@gmail.com
Signed-off-by: Alexei Starovoitov

bpf, docs: Fix typos in instruction-set.rst

2024-02-22T17:07:37+00:00

* "BPF ADD" should be "BPF_ADD".
* "src" should be "src_reg" in several places.  The latter is the field name
  in the instruction.  The former refers to the value of the register, or the
  immediate.
* Add '' around field names in one sentence, for consistency with the rest
  of the document.

Signed-off-by: Dave Thaler 
Acked-by: David Vernet 
Link: https://lore.kernel.org/r/20240221173535.16601-1-dthaler1968@gmail.com
Signed-off-by: Alexei Starovoitov