BPF Instruction Set Architecture (ISA)
draft-ietf-bpf-isa-04
Document | Type | Active Internet-Draft (bpf WG) | |
---|---|---|---|
Author | Dave Thaler | ||
Last updated | 2024-10-04 (Latest revision 2024-06-25) | ||
Replaces | draft-thaler-bpf-isa | ||
RFC stream | Internet Engineering Task Force (IETF) | ||
Intended RFC status | Proposed Standard | ||
Formats | |||
Reviews |
GENART Last Call review
(of
-02)
by Ines Robles
Ready w/nits
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Additional resources |
GitHub Repository
Mailing list discussion |
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Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | David Vernet | ||
Shepherd write-up | Show Last changed 2024-06-13 | ||
IESG | IESG state | RFC Ed Queue | |
Action Holders |
(None)
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Consensus boilerplate | Yes | ||
Telechat date | (None) | ||
Responsible AD | Erik Kline | ||
Send notices to | void@manifault.com | ||
IANA | IANA review state | Version Changed - Review Needed | |
IANA action state | RFC-Ed-Ack | ||
RFC Editor | RFC Editor state | AUTH48 | |
Details |
draft-ietf-bpf-isa-04
Network Working Group D. Thaler, Ed. Internet-Draft 25 June 2024 Intended status: Standards Track Expires: 27 December 2024 BPF Instruction Set Architecture (ISA) draft-ietf-bpf-isa-04 Abstract eBPF (which is no longer an acronym for anything), also commonly referred to as BPF, is a technology with origins in the Linux kernel that can run untrusted programs in a privileged context such as an operating system kernel. This document specifies the BPF instruction set architecture (ISA). Status of This Memo This Internet-Draft is submitted in full conformance with the provisions of BCP 78 and BCP 79. Internet-Drafts are working documents of the Internet Engineering Task Force (IETF). Note that other groups may also distribute working documents as Internet-Drafts. The list of current Internet- Drafts is at https://datatracker.ietf.org/drafts/current/. Internet-Drafts are draft documents valid for a maximum of six months and may be updated, replaced, or obsoleted by other documents at any time. It is inappropriate to use Internet-Drafts as reference material or to cite them other than as "work in progress." This Internet-Draft will expire on 27 December 2024. Copyright Notice Copyright (c) 2024 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (https://trustee.ietf.org/ license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Revised BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Revised BSD License. Thaler Expires 27 December 2024 [Page 1] Internet-Draft BPF ISA June 2024 Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Documentation conventions . . . . . . . . . . . . . . . . . . 3 2.1. Types . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2.2. Functions . . . . . . . . . . . . . . . . . . . . . . . . 4 2.3. Definitions . . . . . . . . . . . . . . . . . . . . . . . 5 2.4. Conformance groups . . . . . . . . . . . . . . . . . . . 5 3. Instruction encoding . . . . . . . . . . . . . . . . . . . . 6 3.1. Basic instruction encoding . . . . . . . . . . . . . . . 6 3.2. Wide instruction encoding . . . . . . . . . . . . . . . . 8 3.3. Instruction classes . . . . . . . . . . . . . . . . . . . 8 4. Arithmetic and jump instructions . . . . . . . . . . . . . . 9 4.1. Arithmetic instructions . . . . . . . . . . . . . . . . . 10 4.2. Byte swap instructions . . . . . . . . . . . . . . . . . 13 4.3. Jump instructions . . . . . . . . . . . . . . . . . . . . 14 4.3.1. Helper functions . . . . . . . . . . . . . . . . . . 17 4.3.2. Program-local functions . . . . . . . . . . . . . . . 17 5. Load and store instructions . . . . . . . . . . . . . . . . . 17 5.1. Regular load and store operations . . . . . . . . . . . . 19 5.2. Sign-extension load operations . . . . . . . . . . . . . 19 5.3. Atomic operations . . . . . . . . . . . . . . . . . . . . 19 5.4. 64-bit immediate instructions . . . . . . . . . . . . . . 21 5.4.1. Maps . . . . . . . . . . . . . . . . . . . . . . . . 22 5.4.2. Platform Variables . . . . . . . . . . . . . . . . . 22 5.5. Legacy BPF Packet access instructions . . . . . . . . . . 23 6. Security Considerations . . . . . . . . . . . . . . . . . . . 23 7. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 24 7.1. BPF Instruction Conformance Group Registry . . . . . . . 24 7.1.1. BPF Instruction Conformance Group Registration Template . . . . . . . . . . . . . . . . . . . . . . 25 7.2. BPF Instruction Set Registry . . . . . . . . . . . . . . 26 7.2.1. BPF Instruction Registration Template . . . . . . . . 27 7.3. Adding instructions . . . . . . . . . . . . . . . . . . . 27 7.4. Deprecating instructions . . . . . . . . . . . . . . . . 28 7.5. Change Control . . . . . . . . . . . . . . . . . . . . . 30 7.6. Expert Review Instructions . . . . . . . . . . . . . . . 30 8. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 30 9. Appendix . . . . . . . . . . . . . . . . . . . . . . . . . . 31 10. References . . . . . . . . . . . . . . . . . . . . . . . . . 45 10.1. Normative References . . . . . . . . . . . . . . . . . . 45 10.2. Informative References . . . . . . . . . . . . . . . . . 46 Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 46 Thaler Expires 27 December 2024 [Page 2] Internet-Draft BPF ISA June 2024 1. Introduction eBPF, also commonly referred to as BPF, is a technology with origins in the Linux kernel that can run untrusted programs in a privileged context such as an operating system kernel. This document specifies the BPF instruction set architecture (ISA). As a historical note, BPF originally stood for Berkeley Packet Filter, but now that it can do so much more than packet filtering, the acronym no longer makes sense. BPF is now considered a standalone term that does not stand for anything. The original BPF is sometimes referred to as cBPF (classic BPF) to distinguish it from the now widely deployed eBPF (extended BPF). 2. Documentation conventions The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and "OPTIONAL" in this document are to be interpreted as described in BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all capitals, as shown here. For brevity and consistency, this document refers to families of types using a shorthand syntax and refers to several expository, mnemonic functions when describing the semantics of instructions. The range of valid values for those types and the semantics of those functions are defined in the following subsections. 2.1. Types This document refers to integer types with the notation _SN_ to specify a type's signedness (_S_) and bit width (_N_), respectively. +===+==========+ | S | Meaning | +===+==========+ | u | unsigned | +---+----------+ | s | signed | +---+----------+ Table 1: Meaning of signedness notation Thaler Expires 27 December 2024 [Page 3] Internet-Draft BPF ISA June 2024 +=====+===========+ | N | Bit width | +=====+===========+ | 8 | 8 bits | +-----+-----------+ | 16 | 16 bits | +-----+-----------+ | 32 | 32 bits | +-----+-----------+ | 64 | 64 bits | +-----+-----------+ | 128 | 128 bits | +-----+-----------+ Table 2: Meaning of bit-width notation For example, _u32_ is a type whose valid values are all the 32-bit unsigned numbers and _s16_ is a type whose valid values are all the 16-bit signed numbers. 2.2. Functions The following byteswap functions are direction-agnostic. That is, the same function is used for conversion in either direction discussed below. * be16: Takes an unsigned 16-bit number and converts it between host byte order and big-endian (IEN137 [IEN137]) byte order. * be32: Takes an unsigned 32-bit number and converts it between host byte order and big-endian byte order. * be64: Takes an unsigned 64-bit number and converts it between host byte order and big-endian byte order. * bswap16: Takes an unsigned 16-bit number in either big- or little- endian format and returns the equivalent number with the same bit width but opposite endianness. * bswap32: Takes an unsigned 32-bit number in either big- or little- endian format and returns the equivalent number with the same bit width but opposite endianness. * bswap64: Takes an unsigned 64-bit number in either big- or little- endian format and returns the equivalent number with the same bit width but opposite endianness. Thaler Expires 27 December 2024 [Page 4] Internet-Draft BPF ISA June 2024 * le16: Takes an unsigned 16-bit number and converts it between host byte order and little-endian byte order. * le32: Takes an unsigned 32-bit number and converts it between host byte order and little-endian byte order. * le64: Takes an unsigned 64-bit number and converts it between host byte order and little-endian byte order. 2.3. Definitions Sign Extend To _sign extend an_ X _-bit number, A, to a_ Y _-bit number, B ,_ means to 1. Copy all X bits from _A_ to the lower X bits of _B_. 2. Set the value of the remaining Y - X bits of _B_ to the value of the most-significant bit of _A_. | *Example* | | Sign extend an 8-bit number A to a 16-bit number B on a big- | endian platform: | | A: 10000110 | B: 11111111 10000110 2.4. Conformance groups An implementation does not need to support all instructions specified in this document (e.g., deprecated instructions). Instead, a number of conformance groups are specified. An implementation MUST support the base32 conformance group and MAY support additional conformance groups, where supporting a conformance group means it MUST support all instructions in that conformance group. The use of named conformance groups enables interoperability between a runtime that executes instructions, and tools such as compilers that generate instructions for the runtime. Thus, capability discovery in terms of conformance groups might be done manually by users or automatically by tools. Each conformance group has a short ASCII label (e.g., "base32") that corresponds to a set of instructions that are mandatory. That is, each instruction has one or more conformance groups of which it is a member. This document defines the following conformance groups: Thaler Expires 27 December 2024 [Page 5] Internet-Draft BPF ISA June 2024 * base32: includes all instructions defined in this specification unless otherwise noted. * base64: includes base32, plus instructions explicitly noted as being in the base64 conformance group. * atomic32: includes 32-bit atomic operation instructions (see Atomic operations (Section 5.3)). * atomic64: includes atomic32, plus 64-bit atomic operation instructions. * divmul32: includes 32-bit division, multiplication, and modulo instructions. * divmul64: includes divmul32, plus 64-bit division, multiplication, and modulo instructions. * packet: deprecated packet access instructions. 3. Instruction encoding BPF has two instruction encodings: * the basic instruction encoding, which uses 64 bits to encode an instruction * the wide instruction encoding, which appends a second 64 bits after the basic instruction for a total of 128 bits. 3.1. Basic instruction encoding A basic instruction is encoded as follows: +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | opcode | regs | offset | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | imm | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ *opcode* operation to perform, encoded as follows: +-+-+-+-+-+-+-+-+ |specific |class| +-+-+-+-+-+-+-+-+ *specific* The format of these bits varies by instruction class Thaler Expires 27 December 2024 [Page 6] Internet-Draft BPF ISA June 2024 *class* The instruction class (see Instruction classes (Section 3.3)) *regs* The source and destination register numbers, encoded as follows on a little-endian host: +-+-+-+-+-+-+-+-+ |src_reg|dst_reg| +-+-+-+-+-+-+-+-+ and as follows on a big-endian host: +-+-+-+-+-+-+-+-+ |dst_reg|src_reg| +-+-+-+-+-+-+-+-+ *src_reg* the source register number (0-10), except where otherwise specified (64-bit immediate instructions (Section 5.4) reuse this field for other purposes) *dst_reg* destination register number (0-10), unless otherwise specified (future instructions might reuse this field for other purposes) *offset* signed integer offset used with pointer arithmetic, except where otherwise specified (some arithmetic instructions reuse this field for other purposes) *imm* signed integer immediate value Note that the contents of multi-byte fields ('offset' and 'imm') are stored using big-endian byte ordering on big-endian hosts and little- endian byte ordering on little-endian hosts. For example: opcode offset imm assembly src_reg dst_reg 07 0 1 00 00 44 33 22 11 r1 += 0x11223344 // little dst_reg src_reg 07 1 0 00 00 11 22 33 44 r1 += 0x11223344 // big Note that most instructions do not use all of the fields. Unused fields SHALL be cleared to zero. Thaler Expires 27 December 2024 [Page 7] Internet-Draft BPF ISA June 2024 3.2. Wide instruction encoding Some instructions are defined to use the wide instruction encoding, which uses two 32-bit immediate values. The 64 bits following the basic instruction format contain a pseudo instruction with 'opcode', 'dst_reg', 'src_reg', and 'offset' all set to zero. This is depicted in the following figure: +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | opcode | regs | offset | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | imm | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | reserved | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ | next_imm | +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+ *opcode* operation to perform, encoded as explained above *regs* The source and destination register numbers (unless otherwise specified), encoded as explained above *offset* signed integer offset used with pointer arithmetic, unless otherwise specified *imm* signed integer immediate value *reserved* unused, set to zero *next_imm* second signed integer immediate value 3.3. Instruction classes The three least significant bits of the 'opcode' field store the instruction class: Thaler Expires 27 December 2024 [Page 8] Internet-Draft BPF ISA June 2024 +=======+=======+======================+==========================+ | class | value | description | reference | +=======+=======+======================+==========================+ | LD | 0x0 | non-standard load | Load and store | | | | operations | instructions (Section 5) | +-------+-------+----------------------+--------------------------+ | LDX | 0x1 | load into register | Load and store | | | | operations | instructions (Section 5) | +-------+-------+----------------------+--------------------------+ | ST | 0x2 | store from immediate | Load and store | | | | operations | instructions (Section 5) | +-------+-------+----------------------+--------------------------+ | STX | 0x3 | store from register | Load and store | | | | operations | instructions (Section 5) | +-------+-------+----------------------+--------------------------+ | ALU | 0x4 | 32-bit arithmetic | Arithmetic and jump | | | | operations | instructions (Section 4) | +-------+-------+----------------------+--------------------------+ | JMP | 0x5 | 64-bit jump | Arithmetic and jump | | | | operations | instructions (Section 4) | +-------+-------+----------------------+--------------------------+ | JMP32 | 0x6 | 32-bit jump | Arithmetic and jump | | | | operations | instructions (Section 4) | +-------+-------+----------------------+--------------------------+ | ALU64 | 0x7 | 64-bit arithmetic | Arithmetic and jump | | | | operations | instructions (Section 4) | +-------+-------+----------------------+--------------------------+ Table 3: Instruction class 4. Arithmetic and jump instructions For arithmetic and jump instructions (ALU, ALU64, JMP and JMP32), the 8-bit 'opcode' field is divided into three parts: +-+-+-+-+-+-+-+-+ | code |s|class| +-+-+-+-+-+-+-+-+ *code* the operation code, whose meaning varies by instruction class *s (source)* the source operand location, which unless otherwise specified is one of: Thaler Expires 27 December 2024 [Page 9] Internet-Draft BPF ISA June 2024 +========+=======+==========================================+ | source | value | description | +========+=======+==========================================+ | K | 0 | use 32-bit 'imm' value as source operand | +--------+-------+------------------------------------------+ | X | 1 | use 'src_reg' register value as source | | | | operand | +--------+-------+------------------------------------------+ Table 4: Source operand location *instruction class* the instruction class (see Instruction classes (Section 3.3)) 4.1. Arithmetic instructions ALU uses 32-bit wide operands while ALU64 uses 64-bit wide operands for otherwise identical operations. ALU64 instructions belong to the base64 conformance group unless noted otherwise. The 'code' field encodes the operation as below, where 'src' refers to the the source operand and 'dst' refers to the value of the destination register. Thaler Expires 27 December 2024 [Page 10] Internet-Draft BPF ISA June 2024 +=======+======+=========+=======================================+ | name | code | offset | description | +=======+======+=========+=======================================+ | ADD | 0x0 | 0 | dst += src | +-------+------+---------+---------------------------------------+ | SUB | 0x1 | 0 | dst -= src | +-------+------+---------+---------------------------------------+ | MUL | 0x2 | 0 | dst *= src | +-------+------+---------+---------------------------------------+ | DIV | 0x3 | 0 | dst = (src != 0) ? (dst / src) : 0 | +-------+------+---------+---------------------------------------+ | SDIV | 0x3 | 1 | dst = (src != 0) ? (dst s/ src) : 0 | +-------+------+---------+---------------------------------------+ | OR | 0x4 | 0 | dst |= src | +-------+------+---------+---------------------------------------+ | AND | 0x5 | 0 | dst &= src | +-------+------+---------+---------------------------------------+ | LSH | 0x6 | 0 | dst <<= (src & mask) | +-------+------+---------+---------------------------------------+ | RSH | 0x7 | 0 | dst >>= (src & mask) | +-------+------+---------+---------------------------------------+ | NEG | 0x8 | 0 | dst = -dst | +-------+------+---------+---------------------------------------+ | MOD | 0x9 | 0 | dst = (src != 0) ? (dst % src) : dst | +-------+------+---------+---------------------------------------+ | SMOD | 0x9 | 1 | dst = (src != 0) ? (dst s% src) : dst | +-------+------+---------+---------------------------------------+ | XOR | 0xa | 0 | dst ^= src | +-------+------+---------+---------------------------------------+ | MOV | 0xb | 0 | dst = src | +-------+------+---------+---------------------------------------+ | MOVSX | 0xb | 8/16/32 | dst = (s8,s16,s32)src | +-------+------+---------+---------------------------------------+ | ARSH | 0xc | 0 | sign extending (Section 2.3) dst >>= | | | | | (src & mask) | +-------+------+---------+---------------------------------------+ | END | 0xd | 0 | byte swap operations (see Byte swap | | | | | instructions (Section 4.2) below) | +-------+------+---------+---------------------------------------+ Table 5: Arithmetic instructions Underflow and overflow are allowed during arithmetic operations, meaning the 64-bit or 32-bit value will wrap. If BPF program execution would result in division by zero, the destination register is instead set to zero. If execution would result in modulo by zero, for ALU64 the value of the destination register is unchanged whereas for ALU the upper 32 bits of the destination register are zeroed. Thaler Expires 27 December 2024 [Page 11] Internet-Draft BPF ISA June 2024 {ADD, X, ALU}, where 'code' = ADD, 'source' = X, and 'class' = ALU, means: dst = (u32) ((u32) dst + (u32) src) where '(u32)' indicates that the upper 32 bits are zeroed. {ADD, X, ALU64} means: dst = dst + src {XOR, K, ALU} means: dst = (u32) dst ^ (u32) imm {XOR, K, ALU64} means: dst = dst ^ imm Note that most arithmetic instructions have 'offset' set to 0. Only three instructions (SDIV, SMOD, MOVSX) have a non-zero 'offset'. Division, multiplication, and modulo operations for ALU are part of the "divmul32" conformance group, and division, multiplication, and modulo operations for ALU64 are part of the "divmul64" conformance group. The division and modulo operations support both unsigned and signed flavors. For unsigned operations (DIV and MOD), for ALU, 'imm' is interpreted as a 32-bit unsigned value. For ALU64, 'imm' is first sign extended (Section 2.3) from 32 to 64 bits, and then interpreted as a 64-bit unsigned value. For signed operations (SDIV and SMOD), for ALU, 'imm' is interpreted as a 32-bit signed value. For ALU64, 'imm' is first sign extended (Section 2.3) from 32 to 64 bits, and then interpreted as a 64-bit signed value. Note that there are varying definitions of the signed modulo operation when the dividend or divisor are negative, where implementations often vary by language such that Python, Ruby, etc. differ from C, Go, Java, etc. This specification requires that signed modulo MUST use truncated division (where -13 % 3 == -1) as implemented in C, Go, etc.: a % n = a - n * trunc(a / n) Thaler Expires 27 December 2024 [Page 12] Internet-Draft BPF ISA June 2024 The MOVSX instruction does a move operation with sign extension. {MOVSX, X, ALU} sign extends (Section 2.3) 8-bit and 16-bit operands into 32-bit operands, and zeroes the remaining upper 32 bits. {MOVSX, X, ALU64} sign extends (Section 2.3) 8-bit, 16-bit, and 32-bit operands into 64-bit operands. Unlike other arithmetic instructions, MOVSX is only defined for register source operands (X). {MOV, K, ALU64} means: dst = (s64)imm {MOV, X, ALU} means: dst = (u32)src {MOVSX, X, ALU} with 'offset' 8 means: dst = (u32)(s32)(s8)src The NEG instruction is only defined when the source bit is clear (K). Shift operations use a mask of 0x3F (63) for 64-bit operations and 0x1F (31) for 32-bit operations. 4.2. Byte swap instructions The byte swap instructions use instruction classes of ALU and ALU64 and a 4-bit 'code' field of END. The byte swap instructions operate on the destination register only and do not use a separate source register or immediate value. For ALU, the 1-bit source operand field in the opcode is used to select what byte order the operation converts from or to. For ALU64, the 1-bit source operand field in the opcode is reserved and MUST be set to 0. Thaler Expires 27 December 2024 [Page 13] Internet-Draft BPF ISA June 2024 +=======+==========+=======+===========================+ | class | source | value | description | +=======+==========+=======+===========================+ | ALU | LE | 0 | convert between host byte | | | | | order and little endian | +-------+----------+-------+---------------------------+ | ALU | BE | 1 | convert between host byte | | | | | order and big endian | +-------+----------+-------+---------------------------+ | ALU64 | Reserved | 0 | do byte swap | | | | | unconditionally | +-------+----------+-------+---------------------------+ Table 6: Byte swap instructions The 'imm' field encodes the width of the swap operations. The following widths are supported: 16, 32 and 64. Width 64 operations belong to the base64 conformance group and other swap operations belong to the base32 conformance group. Examples: {END, LE, ALU} with 'imm' = 16/32/64 means: dst = le16(dst) dst = le32(dst) dst = le64(dst) {END, BE, ALU} with 'imm' = 16/32/64 means: dst = be16(dst) dst = be32(dst) dst = be64(dst) {END, TO, ALU64} with 'imm' = 16/32/64 means: dst = bswap16(dst) dst = bswap32(dst) dst = bswap64(dst) 4.3. Jump instructions JMP32 uses 32-bit wide operands and indicates the base32 conformance group, while JMP uses 64-bit wide operands for otherwise identical operations, and indicates the base64 conformance group unless otherwise specified. The 'code' field encodes the operation as below: Thaler Expires 27 December 2024 [Page 14] Internet-Draft BPF ISA June 2024 +======+=======+=========+===============+==========================+ | code | value | src_reg | description | notes | +======+=======+=========+===============+==========================+ | JA | 0x0 | 0x0 | PC += | {JA, K, JMP} only | | | | | offset | | +------+-------+---------+---------------+--------------------------+ | JA | 0x0 | 0x0 | PC += imm | {JA, K, JMP32} only | +------+-------+---------+---------------+--------------------------+ | JEQ | 0x1 | any | PC += | | | | | | offset if | | | | | | dst == src | | +------+-------+---------+---------------+--------------------------+ | JGT | 0x2 | any | PC += | unsigned | | | | | offset if | | | | | | dst > src | | +------+-------+---------+---------------+--------------------------+ | JGE | 0x3 | any | PC += | unsigned | | | | | offset if | | | | | | dst >= src | | +------+-------+---------+---------------+--------------------------+ | JSET | 0x4 | any | PC += | | | | | | offset if | | | | | | dst & src | | +------+-------+---------+---------------+--------------------------+ | JNE | 0x5 | any | PC += | | | | | | offset if | | | | | | dst != src | | +------+-------+---------+---------------+--------------------------+ | JSGT | 0x6 | any | PC += | signed | | | | | offset if | | | | | | dst > src | | +------+-------+---------+---------------+--------------------------+ | JSGE | 0x7 | any | PC += | signed | | | | | offset if | | | | | | dst >= src | | +------+-------+---------+---------------+--------------------------+ | CALL | 0x8 | 0x0 | call helper | {CALL, K, JMP} only, see | | | | | function by | Helper functions | | | | | static ID | (Section 4.3.1) | +------+-------+---------+---------------+--------------------------+ | CALL | 0x8 | 0x1 | call PC += | {CALL, K, JMP} only, see | | | | | imm | Program-local functions | | | | | | (Section 4.3.2) | +------+-------+---------+---------------+--------------------------+ | CALL | 0x8 | 0x2 | call helper | {CALL, K, JMP} only, see | | | | | function by | Helper functions | | | | | BTF ID | (Section 4.3.1) | +------+-------+---------+---------------+--------------------------+ Thaler Expires 27 December 2024 [Page 15] Internet-Draft BPF ISA June 2024 | EXIT | 0x9 | 0x0 | return | {CALL, K, JMP} only | +------+-------+---------+---------------+--------------------------+ | JLT | 0xa | any | PC += | unsigned | | | | | offset if | | | | | | dst < src | | +------+-------+---------+---------------+--------------------------+ | JLE | 0xb | any | PC += | unsigned | | | | | offset if | | | | | | dst <= src | | +------+-------+---------+---------------+--------------------------+ | JSLT | 0xc | any | PC += | signed | | | | | offset if | | | | | | dst < src | | +------+-------+---------+---------------+--------------------------+ | JSLE | 0xd | any | PC += | signed | | | | | offset if | | | | | | dst <= src | | +------+-------+---------+---------------+--------------------------+ Table 7: Jump instructions where 'PC' denotes the program counter, and the offset to increment by is in units of 64-bit instructions relative to the instruction following the jump instruction. Thus 'PC += 1' skips execution of the next instruction if it's a basic instruction or results in undefined behavior if the next instruction is a 128-bit wide instruction. Example: {JSGE, X, JMP32} means: if (s32)dst s>= (s32)src goto +offset where 's>=' indicates a signed '>=' comparison. {JLE, K, JMP} means: if dst <= (u64)(s64)imm goto +offset {JA, K, JMP32} means: gotol +imm where 'imm' means the branch offset comes from the 'imm' field. Thaler Expires 27 December 2024 [Page 16] Internet-Draft BPF ISA June 2024 Note that there are two flavors of JA instructions. The JMP class permits a 16-bit jump offset specified by the 'offset' field, whereas the JMP32 class permits a 32-bit jump offset specified by the 'imm' field. A > 16-bit conditional jump may be converted to a < 16-bit conditional jump plus a 32-bit unconditional jump. All CALL and JA instructions belong to the base32 conformance group. 4.3.1. Helper functions Helper functions are a concept whereby BPF programs can call into a set of function calls exposed by the underlying platform. Historically, each helper function was identified by a static ID encoded in the 'imm' field. Further documentation of helper functions is outside the scope of this document and standardization is left for future work, but use is widely deployed and more information can be found in platform-specific documentation (e.g., Linux kernel documentation). Platforms that support the BPF Type Format (BTF) support identifying a helper function by a BTF ID encoded in the 'imm' field, where the BTF ID identifies the helper name and type. Further documentation of BTF is outside the scope of this document and standardization is left for future work, but use is widely deployed and more information can be found in platform-specific documentation (e.g., Linux kernel documentation). 4.3.2. Program-local functions Program-local functions are functions exposed by the same BPF program as the caller, and are referenced by offset from the instruction following the call instruction, similar to JA. The offset is encoded in the 'imm' field of the call instruction. An EXIT within the program-local function will return to the caller. 5. Load and store instructions For load and store instructions (LD, LDX, ST, and STX), the 8-bit 'opcode' field is divided as follows: +-+-+-+-+-+-+-+-+ |mode |sz |class| +-+-+-+-+-+-+-+-+ *mode* The mode modifier is one of: Thaler Expires 27 December 2024 [Page 17] Internet-Draft BPF ISA June 2024 +==========+=======+==================+=====================+ | mode | value | description | reference | | modifier | | | | +==========+=======+==================+=====================+ | IMM | 0 | 64-bit immediate | 64-bit immediate | | | | instructions | instructions | | | | | (Section 5.4) | +----------+-------+------------------+---------------------+ | ABS | 1 | legacy BPF | Legacy BPF Packet | | | | packet access | access instructions | | | | (absolute) | (Section 5.5) | +----------+-------+------------------+---------------------+ | IND | 2 | legacy BPF | Legacy BPF Packet | | | | packet access | access instructions | | | | (indirect) | (Section 5.5) | +----------+-------+------------------+---------------------+ | MEM | 3 | regular load and | Regular load and | | | | store operations | store operations | | | | | (Section 5.1) | +----------+-------+------------------+---------------------+ | MEMSX | 4 | sign-extension | Sign-extension load | | | | load operations | operations | | | | | (Section 5.2) | +----------+-------+------------------+---------------------+ | ATOMIC | 6 | atomic | Atomic operations | | | | operations | (Section 5.3) | +----------+-------+------------------+---------------------+ Table 8: Mode modifier *sz (size)* The size modifier is one of: +======+=======+=======================+ | size | value | description | +======+=======+=======================+ | W | 0 | word (4 bytes) | +------+-------+-----------------------+ | H | 1 | half word (2 bytes) | +------+-------+-----------------------+ | B | 2 | byte | +------+-------+-----------------------+ | DW | 3 | double word (8 bytes) | +------+-------+-----------------------+ Table 9: Size modifier Instructions using DW belong to the base64 conformance group. Thaler Expires 27 December 2024 [Page 18] Internet-Draft BPF ISA June 2024 *class* The instruction class (see Instruction classes (Section 3.3)) 5.1. Regular load and store operations The MEM mode modifier is used to encode regular load and store instructions that transfer data between a register and memory. {MEM, <size>, STX} means: *(size *) (dst + offset) = src {MEM, <size>, ST} means: *(size *) (dst + offset) = imm {MEM, <size>, LDX} means: dst = *(unsigned size *) (src + offset) Where '<size>' is one of: B, H, W, or DW, and 'unsigned size' is one of: u8, u16, u32, or u64. 5.2. Sign-extension load operations The MEMSX mode modifier is used to encode sign-extension (Section 2.3) load instructions that transfer data between a register and memory. {MEMSX, <size>, LDX} means: dst = *(signed size *) (src + offset) Where '<size>' is one of: B, H, or W, and 'signed size' is one of: s8, s16, or s32. 5.3. Atomic operations Atomic operations are operations that operate on memory and can not be interrupted or corrupted by other access to the same memory region by other BPF programs or means outside of this specification. All atomic operations supported by BPF are encoded as store operations that use the ATOMIC mode modifier as follows: * {ATOMIC, W, STX} for 32-bit operations, which are part of the "atomic32" conformance group. Thaler Expires 27 December 2024 [Page 19] Internet-Draft BPF ISA June 2024 * {ATOMIC, DW, STX} for 64-bit operations, which are part of the "atomic64" conformance group. * 8-bit and 16-bit wide atomic operations are not supported. The 'imm' field is used to encode the actual atomic operation. Simple atomic operation use a subset of the values defined to encode arithmetic operations in the 'imm' field to encode the atomic operation: +=====+=======+=============+ | imm | value | description | +=====+=======+=============+ | ADD | 0x00 | atomic add | +-----+-------+-------------+ | OR | 0x40 | atomic or | +-----+-------+-------------+ | AND | 0x50 | atomic and | +-----+-------+-------------+ | XOR | 0xa0 | atomic xor | +-----+-------+-------------+ Table 10: Simple atomic operations {ATOMIC, W, STX} with 'imm' = ADD means: *(u32 *)(dst + offset) += src {ATOMIC, DW, STX} with 'imm' = ADD means: *(u64 *)(dst + offset) += src In addition to the simple atomic operations, there also is a modifier and two complex atomic operations: +=========+==============+=============================+ | imm | value | description | +=========+==============+=============================+ | FETCH | 0x01 | modifier: return old value | +---------+--------------+-----------------------------+ | XCHG | 0xe0 | FETCH | atomic exchange | +---------+--------------+-----------------------------+ | CMPXCHG | 0xf0 | FETCH | atomic compare and exchange | +---------+--------------+-----------------------------+ Table 11: Complex atomic operations Thaler Expires 27 December 2024 [Page 20] Internet-Draft BPF ISA June 2024 The FETCH modifier is optional for simple atomic operations, and always set for the complex atomic operations. If the FETCH flag is set, then the operation also overwrites src with the value that was in memory before it was modified. The XCHG operation atomically exchanges src with the value addressed by dst + offset. The CMPXCHG operation atomically compares the value addressed by dst + offset with R0. If they match, the value addressed by dst + offset is replaced with src. In either case, the value that was at dst + offset before the operation is zero-extended and loaded back to R0. 5.4. 64-bit immediate instructions Instructions with the IMM 'mode' modifier use the wide instruction encoding defined in Instruction encoding (Section 3), and use the 'src_reg' field of the basic instruction to hold an opcode subtype. The following table defines a set of {IMM, DW, LD} instructions with opcode subtypes in the 'src_reg' field, using new terms such as "map" defined further below: +=========+================================+==========+==========+ | src_reg | pseudocode | imm type | dst type | +=========+================================+==========+==========+ | 0x0 | dst = (next_imm << 32) | imm | integer | integer | +---------+--------------------------------+----------+----------+ | 0x1 | dst = map_by_fd(imm) | map fd | map | +---------+--------------------------------+----------+----------+ | 0x2 | dst = map_val(map_by_fd(imm)) | map fd | data | | | + next_imm | | address | +---------+--------------------------------+----------+----------+ | 0x3 | dst = var_addr(imm) | variable | data | | | | id | address | +---------+--------------------------------+----------+----------+ | 0x4 | dst = code_addr(imm) | integer | code | | | | | address | +---------+--------------------------------+----------+----------+ | 0x5 | dst = map_by_idx(imm) | map | map | | | | index | | +---------+--------------------------------+----------+----------+ | 0x6 | dst = map_val(map_by_idx(imm)) | map | data | | | + next_imm | index | address | +---------+--------------------------------+----------+----------+ Table 12: 64-bit immediate instructions Thaler Expires 27 December 2024 [Page 21] Internet-Draft BPF ISA June 2024 where * map_by_fd(imm) means to convert a 32-bit file descriptor into an address of a map (see Maps (Section 5.4.1)) * map_by_idx(imm) means to convert a 32-bit index into an address of a map * map_val(map) gets the address of the first value in a given map * var_addr(imm) gets the address of a platform variable (see Platform Variables (Section 5.4.2)) with a given id * code_addr(imm) gets the address of the instruction at a specified relative offset in number of (64-bit) instructions * the 'imm type' can be used by disassemblers for display * the 'dst type' can be used for verification and JIT compilation purposes 5.4.1. Maps Maps are shared memory regions accessible by BPF programs on some platforms. A map can have various semantics as defined in a separate document, and may or may not have a single contiguous memory region, but the 'map_val(map)' is currently only defined for maps that do have a single contiguous memory region. Each map can have a file descriptor (fd) if supported by the platform, where 'map_by_fd(imm)' means to get the map with the specified file descriptor. Each BPF program can also be defined to use a set of maps associated with the program at load time, and 'map_by_idx(imm)' means to get the map with the given index in the set associated with the BPF program containing the instruction. 5.4.2. Platform Variables Platform variables are memory regions, identified by integer ids, exposed by the runtime and accessible by BPF programs on some platforms. The 'var_addr(imm)' operation means to get the address of the memory region identified by the given id. Thaler Expires 27 December 2024 [Page 22] Internet-Draft BPF ISA June 2024 5.5. Legacy BPF Packet access instructions BPF previously introduced special instructions for access to packet data that were carried over from classic BPF. These instructions used an instruction class of LD, a size modifier of W, H, or B, and a mode modifier of ABS or IND. The 'dst_reg' and 'offset' fields were set to zero, and 'src_reg' was set to zero for ABS. However, these instructions are deprecated and SHOULD no longer be used. All legacy packet access instructions belong to the "packet" conformance group. 6. Security Considerations BPF programs could use BPF instructions to do malicious things with memory, CPU, networking, or other system resources. This is not fundamentally different from any other type of software that may run on a device. Execution environments should be carefully designed to only run BPF programs that are trusted and verified, and sandboxing and privilege level separation are key strategies for limiting security and abuse impact. For example, BPF verifiers are well-known and widely deployed and are responsible for ensuring that BPF programs will terminate within a reasonable time, only interact with memory in safe ways, adhere to platform-specified API contracts, and don't use instructions with undefined behavior. This level of verification can often provide a stronger level of security assurance than for other software and operating system code. While the details are out of scope of this document, Linux [LINUX] and PREVAIL [PREVAIL] do provide many details. Future IETF work will document verifier expectations and building blocks for allowing safe execution of untrusted BPF programs. Executing programs using the BPF instruction set also requires either an interpreter or a compiler to translate them to hardware processor native instructions. In general, interpreters are considered a source of insecurity (e.g., gadgets susceptible to side-channel attacks due to speculative execution) whenever one is used in the same memory address space as data with confidentiality concerns. As such, use of a compiler is recommended instead. Compilers should be audited carefully for vulnerabilities to ensure that compilation of a trusted and verified BPF program to native processor instructions does not introduce vulnerabilities. Exposing functionality via BPF extends the interface between the component executing the BPF program and the component submitting it. Careful consideration of what functionality is exposed and how that impacts the security properties desired is required. Thaler Expires 27 December 2024 [Page 23] Internet-Draft BPF ISA June 2024 7. IANA Considerations This document defines two registries. 7.1. BPF Instruction Conformance Group Registry This document defines an IANA registry for BPF instruction conformance groups, as follows: * Name of the registry: BPF Instruction Conformance Groups * Name of the registry group: BPF Instructions * Required information for registrations: See BPF Instruction Conformance Group Registration Template (Section 7.1.1) * Syntax of registry entries: Each entry has the following fields: name, description, includes, excludes, status, and reference. See BPF Instruction Conformance Group Registration Template (Section 7.1.1) for more details. * Registration policy (see Section 4 of [RFC8126] for details): - Permanent: Standards action or IESG Approval - Provisional: Specification required - Historical: Specification required Initial entries in this registry are as follows: Thaler Expires 27 December 2024 [Page 24] Internet-Draft BPF ISA June 2024 +========+============+========+========+==========+===============+ |name |description |includes|excludes|status | reference | +========+============+========+========+==========+===============+ |atomic32|32-bit |- |- |Permanent | RFCXXX Atomic | | |atomic | | | | operations | | |instructions| | | | (Section 5.3) | +--------+------------+--------+--------+----------+---------------+ |atomic64|64-bit |atomic32|- |Permanent | RFCXXX Atomic | | |atomic | | | | operations | | |instructions| | | | (Section 5.3) | +--------+------------+--------+--------+----------+---------------+ |base32 |32-bit base |- |- |Permanent | RFCXXX | | |instructions| | | | | +--------+------------+--------+--------+----------+---------------+ |base64 |64-bit base |base32 |- |Permanent | RFCXXX | | |instructions| | | | | +--------+------------+--------+--------+----------+---------------+ |divmul32|32-bit |- |- |Permanent | RFCXXX | | |division and| | | | Arithmetic | | |modulo | | | | instructions | | | | | | | (Section 4.1) | +--------+------------+--------+--------+----------+---------------+ |divmul64|64-bit |divmul32|- |Permanent | RFCXXX | | |division and| | | | Arithmetic | | |modulo | | | | instructions | | | | | | | (Section 4.1) | +--------+------------+--------+--------+----------+---------------+ |packet |Legacy |- |- |Historical| RFCXXX Legacy | | |packet | | | | BPF Packet | | |instructions| | | | access | | | | | | | instructions | | | | | | | (Section 5.5) | +--------+------------+--------+--------+----------+---------------+ Table 13: Initial conformance groups NOTE TO RFC-EDITOR: Upon publication, please replace RFCXXX above with reference to this document. 7.1.1. BPF Instruction Conformance Group Registration Template This template describes the fields that must be supplied in a registration request suitable for adding to the registry: Name: Alphanumeric label indicating the name of the conformance group. Description: Brief description of the conformance group. Thaler Expires 27 December 2024 [Page 25] Internet-Draft BPF ISA June 2024 Includes: Any other conformance groups that are included by this group. Excludes: Any other conformance groups that are excluded by this group. Status: This reflects the status requested and must be one of 'Permanent', 'Provisional', or 'Historical'. Contact: Person (including contact information) to contact for further information. Change controller: Organization or person (often the author), including contact information, authorized to change this. Reference: A reference to the defining specification. Include full citations for all referenced documents. Registration requests for 'Provisional' registration can be included in an Internet-Draft; when the documents are approved for publication as an RFC, the registration will be updated. 7.2. BPF Instruction Set Registry This document proposes a new IANA registry for BPF instructions, as follows: * Name of the registry: BPF Instruction Set * Name of the registry group: BPF Instructions * Required information for registrations: See BPF Instruction Registration Template (Section 7.2.1) * Syntax of registry entries: Each entry has the following fields: opcode, src, imm, offset, description, groups, and reference. See BPF Instruction Registration Template (Section 7.2.1) for more details. * Registration policy: New instructions require a new entry in the conformance group registry and the same registration policies apply. * Initial registrations: See the Appendix. Instructions other than those listed as deprecated are Permanent. Any listed as deprecated are Historical. Thaler Expires 27 December 2024 [Page 26] Internet-Draft BPF ISA June 2024 7.2.1. BPF Instruction Registration Template This template describes the fields that must be supplied in a registration request suitable for adding to the registry: Opcode: A 1-byte value in hex format indicating the value of the opcode field Src: Either a numeric value indicating the value of the src field, or "any" Imm: Either a value indicating the value of the imm field, or "any" Offset: Either a numeric value indicating the value of the offset field, or "any" Description: Description of what the instruction does, typically in pseudocode Groups: A list of one or more comma-separated conformance groups to which the instruction belongs Contact: Person (including contact information) to contact for further information. Change controller: Organization or person (often the author), including contact information, authorized to change this. Reference: A reference to the defining specification. Include full citations for all referenced documents. Registration requests for 'Provisional' registration can be included in an Internet-Draft; when the documents are approved for publication as an RFC, the registration will be updated. 7.3. Adding instructions A specification may add additional instructions to the BPF Instruction Set registry. Once a conformance group is registered with a set of instructions, no further instructions can be added to that conformance group. A specification should instead create a new conformance group that includes the original conformance group, plus any newly added instructions. Inclusion of the original conformance group is done via the "includes" column of the BPF Instruction Conformance Group Registry, and inclusion of newly added instructions is done via the "groups" column of the BPF Instruction Set Registry. Thaler Expires 27 December 2024 [Page 27] Internet-Draft BPF ISA June 2024 For example, consider an existing hypothetical group called "example" with two instructions in it. One might add two more instructions by first adding an "examplev2" group to the BPF Instruction Conformance Group Registry as follows: +===========+==================+==========+==========+===========+ | name | description | includes | excludes | status | +===========+==================+==========+==========+===========+ | example | Original example | - | - | Permanent | | | instructions | | | | +-----------+------------------+----------+----------+-----------+ | examplev2 | Newer set of | example | - | Permanent | | | example | | | | | | instructions | | | | +-----------+------------------+----------+----------+-----------+ Table 14: Conformance group example for addition And then adding the new instructions into the BPF Instruction Set Registry as follows: +========+=====+================================+===========+ | opcode | ... | description | groups | +========+=====+================================+===========+ | aaa | ... | Original example instruction 1 | example | +--------+-----+--------------------------------+-----------+ | bbb | ... | Original example instruction 2 | example | +--------+-----+--------------------------------+-----------+ | ccc | ... | Added example instruction 3 | examplev2 | +--------+-----+--------------------------------+-----------+ | ddd | ... | Added example instruction 4 | examplev2 | +--------+-----+--------------------------------+-----------+ Table 15: Instruction addition example Supporting the "examplev2" group thus requires supporting all four example instructions. 7.4. Deprecating instructions Deprecating instructions that are part of an existing conformance group can be done by defining a new conformance group for the newly deprecated instructions, and defining a new conformance group that supersedes the existing conformance group containing the instructions, where the new conformance group includes the existing one and excludes the deprecated instruction group. Thaler Expires 27 December 2024 [Page 28] Internet-Draft BPF ISA June 2024 For example, if deprecating an instruction in an existing hypothetical group called "example", two new groups ("legacyexample" and "examplev2") might be registered in the BPF Instruction Conformance Group Registry as follows: +===============+==============+========+===============+==========+ | name | description |includes| excludes |status | +===============+==============+========+===============+==========+ | example | Original |- | - |Permanent | | | example | | | | | | instructions | | | | +---------------+--------------+--------+---------------+----------+ | legacyexample | Legacy |- | - |Historical| | | example | | | | | | instructions | | | | +---------------+--------------+--------+---------------+----------+ | examplev2 | Example |example | legacyexample |Permanent | | | instructions | | | | +---------------+--------------+--------+---------------+----------+ Table 16: Conformance group example for deprecation The BPF Instruction Set Registry entries for the deprecated instructions would then be updated to add "legacyexample" to the set of groups for those instructions, as follows: +========+=====+=============================+===============+ | opcode | ... | description | groups | +========+=====+=============================+===============+ | aaa | ... | Good original instruction 1 | example | +--------+-----+-----------------------------+---------------+ | bbb | ... | Good original instruction 2 | example | +--------+-----+-----------------------------+---------------+ | ccc | ... | Bad original instruction 3 | example, | | | | | legacyexample | +--------+-----+-----------------------------+---------------+ | ddd | ... | Bad original instruction 4 | example, | | | | | legacyexample | +--------+-----+-----------------------------+---------------+ Table 17: Instruction deprecation example Finally, updated implementations that dropped support for the deprecated instructions would then be able to claim conformance to "examplev2" rather than "example". Thaler Expires 27 December 2024 [Page 29] Internet-Draft BPF ISA June 2024 7.5. Change Control Registrations can be updated in a registry by the same mechanism as required for an initial registration. In cases where the original definition of an entry is contained in an IESG-approved document, update of the specification also requires IESG approval. 'Provisional' registrations can be updated by the change controller designated in the existing registration. In addition, the IESG can reassign responsibility for a 'Provisional' registration or can request specific changes to an entry. This will enable changes to be made to entries where the original registrant is out of contact or unwilling or unable to make changes. Transition from 'Provisional' to 'Permanent' status can be requested and approved in the same manner as a new 'Permanent' registration. Transition from 'Permanent' to 'Historical' status requires IESG approval. Transition from 'Provisional' to 'Historical' can be requested by anyone authorized to update the 'Provisional' registration. 7.6. Expert Review Instructions The IANA registries established by this document are informed by written specifications, which themselves are facilitated and approved by an Expert Review Section 5.3 of [RFC8126] process. Designated Experts are expected to consult with the active BPF working group (e.g., via email to the working group's mailing list) if it exists, as well as other interested parties (e.g., via email to one or more active mailing list(s) for relevant BPF communities and platforms). The Designed Expert is expected to verify that the encoding and semantics for any new instructions are properly documented in a public-facing specification. In the event of future RFC documents for ISA extensions, experts may permit early assignment before the RFC document is available, as long as a specification exists which satisfies the above requirements. 8. Acknowledgements This draft was generated from instruction-set.rst in the Linux kernel repository, to which a number of other individuals have authored contributions over time, including Akhil Raj, Alexei Starovoitov, Brendan Jackman, Christoph Hellwig, Daniel Borkmann, Ilya Leoshkevich, Jiong Wang, Jose E. Marchesi, Kosuke Fujimoto, Shahab Vahedi, Tiezhu Yang, Will Hawkins, and Zheng Yejian, with review and suggestions by many others including Alan Jowett, Andrii Nakryiko, David Vernet, Jim Harris, Quentin Monnet, Song Liu, Shung-Hsi Yu, Thaler Expires 27 December 2024 [Page 30] Internet-Draft BPF ISA June 2024 Stanislav Fomichev, Watson Ladd, and Yonghong Song. 9. Appendix Initial values for the BPF Instruction sub-registry are given below. The descriptions in this table are informative. In case of any discrepancy, the reference is authoritative. +======+=======+======+====+========================+========+=============+ |opcode|src_reg|offset|imm |description |groups |reference | +======+=======+======+====+========================+========+=============+ |0x00 |0x0 |0 |any |(additional immediate |base64 |64-bit | | | | | |value) | |immediate | | | | | | | |instructions | | | | | | | |(Section 5.4)| +------+-------+------+----+------------------------+--------+-------------+ |0x04 |0x0 |0 |any |dst = (u32)((u32)dst + |base32 |Arithmetic | | | | | |(u32)imm) | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x05 |0x0 |any |0x00|goto +offset |base32 |Jump | | | | | | | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x06 |0x0 |0 |any |goto +imm |base32 |Jump | | | | | | | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x07 |0x0 |0 |any |dst += imm |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x0c |any |0 |0x00|dst = (u32)((u32)dst + |base32 |Arithmetic | | | | | |(u32)src) | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x0f |any |0 |0x00|dst += src |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x14 |0x0 |0 |any |dst = (u32)((u32)dst - |base32 |Arithmetic | | | | | |(u32)imm) | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x15 |0x0 |any |any |if dst == imm goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ Thaler Expires 27 December 2024 [Page 31] Internet-Draft BPF ISA June 2024 |0x16 |0x0 |any |any |if (u32)dst == imm goto |base32 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x17 |0x0 |0 |any |dst -= imm |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x18 |0x0 |0 |any |dst = (next_imm << 32) ||base64 |64-bit | | | | | |imm | |immediate | | | | | | | |instructions | | | | | | | |(Section 5.4)| +------+-------+------+----+------------------------+--------+-------------+ |0x18 |0x1 |0 |any |dst = map_by_fd(imm) |base64 |64-bit | | | | | | | |immediate | | | | | | | |instructions | | | | | | | |(Section 5.4)| +------+-------+------+----+------------------------+--------+-------------+ |0x18 |0x2 |0 |any |dst = |base64 |64-bit | | | | | |map_val(map_by_fd(imm)) | |immediate | | | | | |+ next_imm | |instructions | | | | | | | |(Section 5.4)| +------+-------+------+----+------------------------+--------+-------------+ |0x18 |0x3 |0 |any |dst = var_addr(imm) |base64 |64-bit | | | | | | | |immediate | | | | | | | |instructions | | | | | | | |(Section 5.4)| +------+-------+------+----+------------------------+--------+-------------+ |0x18 |0x4 |0 |any |dst = code_addr(imm) |base64 |64-bit | | | | | | | |immediate | | | | | | | |instructions | | | | | | | |(Section 5.4)| +------+-------+------+----+------------------------+--------+-------------+ |0x18 |0x5 |0 |any |dst = map_by_idx(imm) |base64 |64-bit | | | | | | | |immediate | | | | | | | |instructions | | | | | | | |(Section 5.4)| +------+-------+------+----+------------------------+--------+-------------+ |0x18 |0x6 |0 |any |dst = |base64 |64-bit | | | | | |map_val(map_by_idx(imm))| |immediate | | | | | |+ next_imm | |instructions | | | | | | | |(Section 5.4)| +------+-------+------+----+------------------------+--------+-------------+ |0x1c |any |0 |0x00|dst = (u32)((u32)dst - |base32 |Arithmetic | | | | | |(u32)src) | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x1d |any |any |0x00|if dst == src goto |base64 |Jump | Thaler Expires 27 December 2024 [Page 32] Internet-Draft BPF ISA June 2024 | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x1e |any |any |0x00|if (u32)dst == (u32)src |base32 |Jump | | | | | |goto +offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x1f |any |0 |0x00|dst -= src |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x20 |0x0 |0 |any |(deprecated, |packet |Legacy BPF | | | | | |implementation-specific)| |Packet access| | | | | | | |instructions | | | | | | | |(Section 5.5)| +------+-------+------+----+------------------------+--------+-------------+ |0x24 |0x0 |0 |any |dst = (u32)(dst * imm) |divmul32|Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x25 |0x0 |any |any |if dst > imm goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x26 |0x0 |any |any |if (u32)dst > imm goto |base32 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x27 |0x0 |0 |any |dst *= imm |divmul64|Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x28 |0x0 |0 |any |(deprecated, |packet |Legacy BPF | | | | | |implementation-specific)| |Packet access| | | | | | | |instructions | | | | | | | |(Section 5.5)| +------+-------+------+----+------------------------+--------+-------------+ |0x2c |any |0 |0x00|dst = (u32)(dst * src) |divmul32|Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x2d |any |any |0x00|if dst > src goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x2e |any |any |0x00|if (u32)dst > (u32)src |base32 |Jump | | | | | |goto +offset | |instructions | | | | | | | |(Section 4.3)| Thaler Expires 27 December 2024 [Page 33] Internet-Draft BPF ISA June 2024 +------+-------+------+----+------------------------+--------+-------------+ |0x2f |any |0 |0x00|dst *= src |divmul64|Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x30 |0x0 |0 |any |(deprecated, |packet |Legacy BPF | | | | | |implementation-specific)| |Packet access| | | | | | | |instructions | | | | | | | |(Section 5.5)| +------+-------+------+----+------------------------+--------+-------------+ |0x34 |0x0 |0 |any |dst = (u32)((imm != 0) ?|divmul32|Arithmetic | | | | | |((u32)dst / (u32)imm) : | |instructions | | | | | |0) | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x34 |0x0 |1 |any |dst = (u32)((imm != 0) ?|divmul32|Arithmetic | | | | | |((s32)dst s/ imm) : 0) | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x35 |0x0 |any |any |if dst >= imm goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x36 |0x0 |any |any |if (u32)dst >= imm goto |base32 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x37 |0x0 |0 |any |dst = (imm != 0) ? (dst |divmul64|Arithmetic | | | | | |/ (u32)imm) : 0 | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x37 |0x0 |1 |any |dst = (imm != 0) ? (dst |divmul64|Arithmetic | | | | | |s/ imm) : 0 | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x3c |any |0 |0x00|dst = (u32)((src != 0) ?|divmul32|Arithmetic | | | | | |((u32)dst / (u32)src) : | |instructions | | | | | |0) | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x3c |any |1 |0x00|dst = (u32)((src != 0) ?|divmul32|Arithmetic | | | | | |((s32)dst s/(s32)src) : | |instructions | | | | | |0) | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x3d |any |any |0x00|if dst >= src goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x3e |any |any |0x00|if (u32)dst >= (u32)src |base32 |Jump | | | | | |goto +offset | |instructions | Thaler Expires 27 December 2024 [Page 34] Internet-Draft BPF ISA June 2024 | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x3f |any |0 |0x00|dst = (src != 0) ? (dst |divmul64|Arithmetic | | | | | |/ src) : 0 | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x3f |any |1 |0x00|dst = (src != 0) ? (dst |divmul64|Arithmetic | | | | | |s/ src) : 0 | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x40 |any |0 |any |(deprecated, |packet |Legacy BPF | | | | | |implementation-specific)| |Packet access| | | | | | | |instructions | | | | | | | |(Section 5.5)| +------+-------+------+----+------------------------+--------+-------------+ |0x44 |0x0 |0 |any |dst = (u32)(dst | imm) |base32 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x45 |0x0 |any |any |if dst & imm goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x46 |0x0 |any |any |if (u32)dst & imm goto |base32 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x47 |0x0 |0 |any |dst |= imm |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x48 |any |0 |any |(deprecated, |packet |Legacy BPF | | | | | |implementation-specific)| |Packet access| | | | | | | |instructions | | | | | | | |(Section 5.5)| +------+-------+------+----+------------------------+--------+-------------+ |0x4c |any |0 |0x00|dst = (u32)(dst | src) |base32 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x4d |any |any |0x00|if dst & src goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x4e |any |any |0x00|if (u32)dst & (u32)src |base32 |Jump | | | | | |goto +offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ Thaler Expires 27 December 2024 [Page 35] Internet-Draft BPF ISA June 2024 |0x4f |any |0 |0x00|dst |= src |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x50 |any |0 |any |(deprecated, |packet |Legacy BPF | | | | | |implementation-specific)| |Packet access| | | | | | | |instructions | | | | | | | |(Section 5.5)| +------+-------+------+----+------------------------+--------+-------------+ |0x54 |0x0 |0 |any |dst = (u32)(dst & imm) |base32 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x55 |0x0 |any |any |if dst != imm goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x56 |0x0 |any |any |if (u32)dst != imm goto |base32 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x57 |0x0 |0 |any |dst &= imm |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x5c |any |0 |0x00|dst = (u32)(dst & src) |base32 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x5d |any |any |0x00|if dst != src goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x5e |any |any |0x00|if (u32)dst != (u32)src |base32 |Jump | | | | | |goto +offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x5f |any |0 |0x00|dst &= src |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x61 |any |any |0x00|dst = *(u32 *)(src + |base32 |Load and | | | | | |offset) | |store | | | | | | | |instructions | | | | | | | |(Section 5) | +------+-------+------+----+------------------------+--------+-------------+ |0x62 |0x0 |any |any |*(u32 *)(dst + offset) =|base32 |Load and | | | | | |imm | |store | Thaler Expires 27 December 2024 [Page 36] Internet-Draft BPF ISA June 2024 | | | | | | |instructions | | | | | | | |(Section 5) | +------+-------+------+----+------------------------+--------+-------------+ |0x63 |any |any |0x00|*(u32 *)(dst + offset) =|base32 |Load and | | | | | |src | |store | | | | | | | |instructions | | | | | | | |(Section 5) | +------+-------+------+----+------------------------+--------+-------------+ |0x64 |0x0 |0 |any |dst = (u32)(dst << imm) |base32 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x65 |0x0 |any |any |if dst s> imm goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x66 |0x0 |any |any |if (s32)dst s> (s32)imm |base32 |Jump | | | | | |goto +offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x67 |0x0 |0 |any |dst <<= imm |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x69 |any |any |0x00|dst = *(u16 *)(src + |base32 |Load and | | | | | |offset) | |store | | | | | | | |instructions | | | | | | | |(Section 5) | +------+-------+------+----+------------------------+--------+-------------+ |0x6a |0x0 |any |any |*(u16 *)(dst + offset) =|base32 |Load and | | | | | |imm | |store | | | | | | | |instructions | | | | | | | |(Section 5) | +------+-------+------+----+------------------------+--------+-------------+ |0x6b |any |any |0x00|*(u16 *)(dst + offset) =|base32 |Load and | | | | | |src | |store | | | | | | | |instructions | | | | | | | |(Section 5) | +------+-------+------+----+------------------------+--------+-------------+ |0x6c |any |0 |0x00|dst = (u32)(dst << src) |base32 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x6d |any |any |0x00|if dst s> src goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x6e |any |any |0x00|if (s32)dst s> (s32)src |base32 |Jump | Thaler Expires 27 December 2024 [Page 37] Internet-Draft BPF ISA June 2024 | | | | |goto +offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x6f |any |0 |0x00|dst <<= src |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x71 |any |any |0x00|dst = *(u8 *)(src + |base32 |Load and | | | | | |offset) | |store | | | | | | | |instructions | | | | | | | |(Section 5) | +------+-------+------+----+------------------------+--------+-------------+ |0x72 |0x0 |any |any |*(u8 *)(dst + offset) = |base32 |Load and | | | | | |imm | |store | | | | | | | |instructions | | | | | | | |(Section 5) | +------+-------+------+----+------------------------+--------+-------------+ |0x73 |any |any |0x00|*(u8 *)(dst + offset) = |base32 |Load and | | | | | |src | |store | | | | | | | |instructions | | | | | | | |(Section 5) | +------+-------+------+----+------------------------+--------+-------------+ |0x74 |0x0 |0 |any |dst = (u32)(dst >> imm) |base32 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x75 |0x0 |any |any |if dst s>= imm goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x76 |0x0 |any |any |if (s32)dst s>= (s32)imm|base32 |Jump | | | | | |goto +offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x77 |0x0 |0 |any |dst >>= imm |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x79 |any |any |0x00|dst = *(u64 *)(src + |base64 |Load and | | | | | |offset) | |store | | | | | | | |instructions | | | | | | | |(Section 5) | +------+-------+------+----+------------------------+--------+-------------+ |0x7a |0x0 |any |any |*(u64 *)(dst + offset) =|base64 |Load and | | | | | |imm | |store | | | | | | | |instructions | | | | | | | |(Section 5) | +------+-------+------+----+------------------------+--------+-------------+ Thaler Expires 27 December 2024 [Page 38] Internet-Draft BPF ISA June 2024 |0x7b |any |any |0x00|*(u64 *)(dst + offset) =|base64 |Load and | | | | | |src | |store | | | | | | | |instructions | | | | | | | |(Section 5) | +------+-------+------+----+------------------------+--------+-------------+ |0x7c |any |0 |0x00|dst = (u32)(dst >> src) |base32 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x7d |any |any |0x00|if dst s>= src goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x7e |any |any |0x00|if (s32)dst s>= (s32)src|base32 |Jump | | | | | |goto +offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x7f |any |0 |0x00|dst >>= src |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x84 |0x0 |0 |0x00|dst = (u32)-dst |base32 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x85 |0x0 |0 |any |call helper function by |base32 |Helper | | | | | |static ID | |functions | | | | | | | |(Section | | | | | | | |4.3.1) | +------+-------+------+----+------------------------+--------+-------------+ |0x85 |0x1 |0 |any |call PC += imm |base32 |Program-local| | | | | | | |functions | | | | | | | |(Section | | | | | | | |4.3.2) | +------+-------+------+----+------------------------+--------+-------------+ |0x85 |0x2 |0 |any |call helper function by |base32 |Helper | | | | | |BTF ID | |functions | | | | | | | |(Section | | | | | | | |4.3.1) | +------+-------+------+----+------------------------+--------+-------------+ |0x87 |0x0 |0 |0x00|dst = -dst |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x94 |0x0 |0 |any |dst = (u32)((imm != |divmul32|Arithmetic | | | | | |0)?((u32)dst % (u32)imm)| |instructions | | | | | |: dst) | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ Thaler Expires 27 December 2024 [Page 39] Internet-Draft BPF ISA June 2024 |0x94 |0x0 |1 |any |dst = (u32)((imm != 0) ?|divmul32|Arithmetic | | | | | |((s32)dst s% imm) : dst)| |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x95 |0x0 |0 |0x00|return |base32 |Jump | | | | | | | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0x97 |0x0 |0 |any |dst = (imm != 0) ? (dst |divmul64|Arithmetic | | | | | |% (u32)imm) : dst | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x97 |0x0 |1 |any |dst = (imm != 0) ? (dst |divmul64|Arithmetic | | | | | |s% imm) : dst | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x9c |any |0 |0x00|dst = (u32)((src != |divmul32|Arithmetic | | | | | |0)?((u32)dst % (u32)src)| |instructions | | | | | |: dst) | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x9c |any |1 |0x00|dst = (u32)((src != |divmul32|Arithmetic | | | | | |0)?((s32)dst s% | |instructions | | | | | |(s32)src) :dst) | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x9f |any |0 |0x00|dst = (src != 0) ? (dst |divmul64|Arithmetic | | | | | |% src) : dst | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0x9f |any |1 |0x00|dst = (src != 0) ? (dst |divmul64|Arithmetic | | | | | |s% src) : dst | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0xa4 |0x0 |0 |any |dst = (u32)(dst ^ imm) |base32 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0xa5 |0x0 |any |any |if dst < imm goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xa6 |0x0 |any |any |if (u32)dst < imm goto |base32 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xa7 |0x0 |0 |any |dst ^= imm |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ Thaler Expires 27 December 2024 [Page 40] Internet-Draft BPF ISA June 2024 |0xac |any |0 |0x00|dst = (u32)(dst ^ src) |base32 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0xad |any |any |0x00|if dst < src goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xae |any |any |0x00|if (u32)dst < (u32)src |base32 |Jump | | | | | |goto +offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xaf |any |0 |0x00|dst ^= src |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0xb4 |0x0 |0 |any |dst = (u32) imm |base32 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0xb5 |0x0 |any |any |if dst <= imm goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xb6 |0x0 |any |any |if (u32)dst <= imm goto |base32 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xb7 |0x0 |0 |any |dst = imm |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0xbc |any |0 |0x00|dst = (u32) src |base32 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0xbc |any |8 |0x00|dst = (u32) (s32) (s8) |base32 |Arithmetic | | | | | |src | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0xbc |any |16 |0x00|dst = (u32) (s32) (s16) |base32 |Arithmetic | | | | | |src | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0xbd |any |any |0x00|if dst <= src goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ Thaler Expires 27 December 2024 [Page 41] Internet-Draft BPF ISA June 2024 |0xbe |any |any |0x00|if (u32)dst <= (u32)src |base32 |Jump | | | | | |goto +offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xbf |any |0 |0x00|dst = src |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0xbf |any |8 |0x00|dst = (s64) (s8) src |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0xbf |any |16 |0x00|dst = (s64) (s16) src |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0xbf |any |32 |0x00|dst = (s64) (s32) src |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0xc3 |any |any |0x00|lock *(u32 *)(dst + |atomic32|Atomic | | | | | |offset) += src | |operations | | | | | | | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xc3 |any |any |0x01|src = |atomic32|Atomic | | | | | |atomic_fetch_add_32((u32| |operations | | | | | |*)(dst + offset), src) | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xc3 |any |any |0x40|lock *(u32 *)(dst + |atomic32|Atomic | | | | | |offset) |= src | |operations | | | | | | | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xc3 |any |any |0x41|src = |atomic32|Atomic | | | | | |atomic_fetch_or_32((u32 | |operations | | | | | |*)(dst + offset), src) | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xc3 |any |any |0x50|lock *(u32 *)(dst + |atomic32|Atomic | | | | | |offset) &= src | |operations | | | | | | | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xc3 |any |any |0x51|src = |atomic32|Atomic | | | | | |atomic_fetch_and_32((u32| |operations | | | | | |*)(dst + offset), src) | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xc3 |any |any |0xa0|lock *(u32 *)(dst + |atomic32|Atomic | | | | | |offset) ^= src | |operations | | | | | | | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ Thaler Expires 27 December 2024 [Page 42] Internet-Draft BPF ISA June 2024 |0xc3 |any |any |0xa1|src = |atomic32|Atomic | | | | | |atomic_fetch_xor_32((u32| |operations | | | | | |*)(dst + offset), src) | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xc3 |any |any |0xe1|src = xchg_32((u32 |atomic32|Atomic | | | | | |*)(dst + offset), src) | |operations | | | | | | | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xc3 |any |any |0xf1|r0 = cmpxchg_32((u32 |atomic32|Atomic | | | | | |*)(dst + offset), r0, | |operations | | | | | |src) | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xc4 |0x0 |0 |any |dst = (u32)(dst s>> imm)|base32 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0xc5 |0x0 |any |any |if dst s< imm goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xc6 |0x0 |any |any |if (s32)dst s< (s32)imm |base32 |Jump | | | | | |goto +offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xc7 |0x0 |0 |any |dst s>>= imm |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0xcc |any |0 |0x00|dst = (u32)(dst s>> src)|base32 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0xcd |any |any |0x00|if dst s< src goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xce |any |any |0x00|if (s32)dst s< (s32)src |base32 |Jump | | | | | |goto +offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xcf |any |0 |0x00|dst s>>= src |base64 |Arithmetic | | | | | | | |instructions | | | | | | | |(Section 4.1)| +------+-------+------+----+------------------------+--------+-------------+ |0xd4 |0x0 |0 |0x10|dst = htole16(dst) |base32 |Byte swap | | | | | | | |instructions | | | | | | | |(Section 4.2)| +------+-------+------+----+------------------------+--------+-------------+ Thaler Expires 27 December 2024 [Page 43] Internet-Draft BPF ISA June 2024 |0xd4 |0x0 |0 |0x20|dst = htole32(dst) |base32 |Byte swap | | | | | | | |instructions | | | | | | | |(Section 4.2)| +------+-------+------+----+------------------------+--------+-------------+ |0xd4 |0x0 |0 |0x40|dst = htole64(dst) |base64 |Byte swap | | | | | | | |instructions | | | | | | | |(Section 4.2)| +------+-------+------+----+------------------------+--------+-------------+ |0xd5 |0x0 |any |any |if dst s<= imm goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xd6 |0x0 |any |any |if (s32)dst s<= (s32)imm|base32 |Jump | | | | | |goto +offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xd7 |0x0 |0 |0x10|dst = bswap16(dst) |base32 |Byte swap | | | | | | | |instructions | | | | | | | |(Section 4.2)| +------+-------+------+----+------------------------+--------+-------------+ |0xd7 |0x0 |0 |0x20|dst = bswap32(dst) |base32 |Byte swap | | | | | | | |instructions | | | | | | | |(Section 4.2)| +------+-------+------+----+------------------------+--------+-------------+ |0xd7 |0x0 |0 |0x40|dst = bswap64(dst) |base64 |Byte swap | | | | | | | |instructions | | | | | | | |(Section 4.2)| +------+-------+------+----+------------------------+--------+-------------+ |0xdb |any |any |0x00|lock *(u64 *)(dst + |atomic64|Atomic | | | | | |offset) += src | |operations | | | | | | | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xdb |any |any |0x01|src = |atomic64|Atomic | | | | | |atomic_fetch_add_64((u64| |operations | | | | | |*)(dst + offset), src) | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xdb |any |any |0x40|lock *(u64 *)(dst + |atomic64|Atomic | | | | | |offset) |= src | |operations | | | | | | | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xdb |any |any |0x41|src = |atomic64|Atomic | | | | | |atomic_fetch_or_64((u64 | |operations | | | | | |*)(dst + offset), src) | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xdb |any |any |0x50|lock *(u64 *)(dst + |atomic64|Atomic | | | | | |offset) &= src | |operations | | | | | | | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ Thaler Expires 27 December 2024 [Page 44] Internet-Draft BPF ISA June 2024 |0xdb |any |any |0x51|src = |atomic64|Atomic | | | | | |atomic_fetch_and_64((u64| |operations | | | | | |*)(dst + offset), src) | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xdb |any |any |0xa0|lock *(u64 *)(dst + |atomic64|Atomic | | | | | |offset) ^= src | |operations | | | | | | | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xdb |any |any |0xa1|src = |atomic64|Atomic | | | | | |atomic_fetch_xor_64((u64| |operations | | | | | |*)(dst + offset), src) | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xdb |any |any |0xe1|src = xchg_64((u64 |atomic64|Atomic | | | | | |*)(dst + offset), src) | |operations | | | | | | | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xdb |any |any |0xf1|r0 = cmpxchg_64((u64 |atomic64|Atomic | | | | | |*)(dst + offset), r0, | |operations | | | | | |src) | |(Section 5.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xdc |0x0 |0 |0x10|dst = htobe16(dst) |base32 |Byte swap | | | | | | | |instructions | | | | | | | |(Section 4.2)| +------+-------+------+----+------------------------+--------+-------------+ |0xdc |0x0 |0 |0x20|dst = htobe32(dst) |base32 |Byte swap | | | | | | | |instructions | | | | | | | |(Section 4.2)| +------+-------+------+----+------------------------+--------+-------------+ |0xdc |0x0 |0 |0x40|dst = htobe64(dst) |base64 |Byte swap | | | | | | | |instructions | | | | | | | |(Section 4.2)| +------+-------+------+----+------------------------+--------+-------------+ |0xdd |any |any |0x00|if dst s<= src goto |base64 |Jump | | | | | |+offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ |0xde |any |any |0x00|if (s32)dst s<= (s32)src|base32 |Jump | | | | | |goto +offset | |instructions | | | | | | | |(Section 4.3)| +------+-------+------+----+------------------------+--------+-------------+ Table 18: BPF Instruction sub-registry initial values 10. References 10.1. Normative References Thaler Expires 27 December 2024 [Page 45] Internet-Draft BPF ISA June 2024 [IEN137] Cohen, D., "On Holy Wars and a Plea for Peace", IEN 137, April 1980. [RFC2119] Bradner, S., "Key words for use in RFCs to Indicate Requirement Levels", BCP 14, RFC 2119, DOI 10.17487/RFC2119, March 1997, <https://www.rfc-editor.org/rfc/rfc2119>. [RFC8126] Cotton, M., Leiba, B., and T. Narten, "Guidelines for Writing an IANA Considerations Section in RFCs", BCP 26, RFC 8126, DOI 10.17487/RFC8126, June 2017, <https://www.rfc-editor.org/rfc/rfc8126>. [RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC 2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174, May 2017, <https://www.rfc-editor.org/rfc/rfc8174>. 10.2. Informative References [LINUX] "eBPF verifier", <https://www.kernel.org/doc/html/latest/bpf/ verifier.html>. [PREVAIL] Gershuni, E., Amit, N., Gurfinkel, A., Narodytska, N., Navas, J., Rinetzky, N., Ryzhyk, L., and M. Sagiv, "Simple and Precise Static Analysis of Untrusted Linux Kernel Extensions", DOI 10.1145/3314221.3314590, June 2019, <https://doi.org/10.1145/3314221.3314590>. Author's Address Dave Thaler (editor) Redmond, WA 98052 United States of America Email: dave.thaler.ietf@gmail.com Thaler Expires 27 December 2024 [Page 46]