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eBPF Instruction Set Specification, v1.0
draft-thaler-bpf-isa-01

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This is an older version of an Internet-Draft whose latest revision state is "Replaced".
Author Dave Thaler
Last updated 2023-07-26 (Latest revision 2023-07-10)
Replaced by draft-ietf-bpf-isa, draft-ietf-bpf-isa
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draft-thaler-bpf-isa-01
Network Working Group                                     D. Thaler, Ed.
Internet-Draft                                                 Microsoft
Intended status: Standards Track                            10 July 2023
Expires: 11 January 2024

                eBPF Instruction Set Specification, v1.0
                        draft-thaler-bpf-isa-01

Abstract

   This document specifies version 1.0 of the eBPF instruction set.

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 11 January 2024.

Copyright Notice

   Copyright (c) 2023 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.

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Table of Contents

   1.  Documentation conventions . . . . . . . . . . . . . . . . . .   2
   2.  Registers and calling convention  . . . . . . . . . . . . . .   2
   3.  Instruction encoding  . . . . . . . . . . . . . . . . . . . .   3
     3.1.  Instruction classes . . . . . . . . . . . . . . . . . . .   4
   4.  Arithmetic and jump instructions  . . . . . . . . . . . . . .   5
     4.1.  Arithmetic instructions . . . . . . . . . . . . . . . . .   6
       4.1.1.  Byte swap instructions  . . . . . . . . . . . . . . .   8
     4.2.  Jump instructions . . . . . . . . . . . . . . . . . . . .   9
       4.2.1.  Helper functions  . . . . . . . . . . . . . . . . . .  10
       4.2.2.  Program-local functions . . . . . . . . . . . . . . .  11
   5.  Load and store instructions . . . . . . . . . . . . . . . . .  11
     5.1.  Regular load and store operations . . . . . . . . . . . .  12
     5.2.  Atomic operations . . . . . . . . . . . . . . . . . . . .  12
     5.3.  64-bit immediate instructions . . . . . . . . . . . . . .  14
       5.3.1.  Maps  . . . . . . . . . . . . . . . . . . . . . . . .  16
       5.3.2.  Platform Variables  . . . . . . . . . . . . . . . . .  16
     5.4.  Legacy BPF Packet access instructions . . . . . . . . . .  16
   6.  Acknowledgements  . . . . . . . . . . . . . . . . . . . . . .  16
   7.  Appendix  . . . . . . . . . . . . . . . . . . . . . . . . . .  17
   Author's Address  . . . . . . . . . . . . . . . . . . . . . . . .  31

1.  Documentation conventions

   For brevity, this document uses the type notion "u64", "u32", etc.
   to mean an unsigned integer whose width is the specified number of
   bits, and "s32", etc. to mean a signed integer of the specified
   number of bits.

2.  Registers and calling convention

   eBPF has 10 general purpose registers and a read-only frame pointer
   register, all of which are 64-bits wide.

   The eBPF calling convention is defined as:

   *  R0: return value from function calls, and exit value for eBPF
      programs

   *  R1 - R5: arguments for function calls

   *  R6 - R9: callee saved registers that function calls will preserve

   *  R10: read-only frame pointer to access stack

   R0 - R5 are scratch registers and eBPF programs needs to spill/fill
   them if necessary across calls.

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3.  Instruction encoding

   eBPF 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-bit
      immediate (i.e., constant) value after the basic instruction for a
      total of 128 bits.

   The fields conforming an encoded basic instruction are stored in the
   following order:

  opcode:8 src_reg:4 dst_reg:4 offset:16 imm:32 // In little-endian BPF.
  opcode:8 dst_reg:4 src_reg:4 offset:16 imm:32 // In big-endian BPF.

   *imm*  signed integer immediate value

   *offset*  signed integer offset used with pointer arithmetic

   *src_reg*  the source register number (0-10), except where otherwise
      specified (64-bit immediate instructions (Section 5.3) reuse this
      field for other purposes)

   *dst_reg*  destination register number (0-10)

   *opcode*  operation to perform

   Note that the contents of multi-byte fields ('imm' and 'offset') are
   stored using big-endian byte ordering in big-endian BPF and little-
   endian byte ordering in little-endian BPF.

   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.

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   As discussed below in 64-bit immediate instructions (Section 5.3), a
   64-bit immediate instruction uses a 64-bit immediate value that is
   constructed as follows.  The 64 bits following the basic instruction
   contain a pseudo instruction using the same format but with opcode,
   dst_reg, src_reg, and offset all set to zero, and imm containing the
   high 32 bits of the immediate value.

   This is depicted in the following figure:

           basic_instruction
     .-----------------------------.
     |                             |
     code:8 regs:8 offset:16 imm:32 unused:32 imm:32
                                    |              |
                                    '--------------'
                                   pseudo instruction

   Thus the 64-bit immediate value is constructed as follows:

   |  imm64 = (next_imm << 32) | imm

   where 'next_imm' refers to the imm value of the pseudo instruction
   following the basic instruction.  The unused bytes in the pseudo
   instruction are reserved and shall be cleared to zero.

3.1.  Instruction classes

   The three LSB bits of the 'opcode' field store the instruction class:

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   +===========+=======+====================+==========================+
   | class     | value | description        | reference                |
   +===========+=======+====================+==========================+
   | BPF_LD    | 0x00  | non-standard       | Load and store           |
   |           |       | load operations    | instructions (Section 5) |
   +-----------+-------+--------------------+--------------------------+
   | BPF_LDX   | 0x01  | load into          | Load and store           |
   |           |       | register           | instructions (Section 5) |
   |           |       | operations         |                          |
   +-----------+-------+--------------------+--------------------------+
   | BPF_ST    | 0x02  | store from         | Load and store           |
   |           |       | immediate          | instructions (Section 5) |
   |           |       | operations         |                          |
   +-----------+-------+--------------------+--------------------------+
   | BPF_STX   | 0x03  | store from         | Load and store           |
   |           |       | register           | instructions (Section 5) |
   |           |       | operations         |                          |
   +-----------+-------+--------------------+--------------------------+
   | BPF_ALU   | 0x04  | 32-bit             | Arithmetic and jump      |
   |           |       | arithmetic         | instructions (Section 4) |
   |           |       | operations         |                          |
   +-----------+-------+--------------------+--------------------------+
   | BPF_JMP   | 0x05  | 64-bit jump        | Arithmetic and jump      |
   |           |       | operations         | instructions (Section 4) |
   +-----------+-------+--------------------+--------------------------+
   | BPF_JMP32 | 0x06  | 32-bit jump        | Arithmetic and jump      |
   |           |       | operations         | instructions (Section 4) |
   +-----------+-------+--------------------+--------------------------+
   | BPF_ALU64 | 0x07  | 64-bit             | Arithmetic and jump      |
   |           |       | arithmetic         | instructions (Section 4) |
   |           |       | operations         |                          |
   +-----------+-------+--------------------+--------------------------+

                                  Table 1

4.  Arithmetic and jump instructions

   For arithmetic and jump instructions (BPF_ALU, BPF_ALU64, BPF_JMP and
   BPF_JMP32), the 8-bit 'opcode' field is divided into three parts:

               +==============+========+===================+
               | 4 bits (MSB) | 1 bit  | 3 bits (LSB)      |
               +==============+========+===================+
               | code         | source | instruction class |
               +--------------+--------+-------------------+

                                  Table 2

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   *code*  the operation code, whose meaning varies by instruction class

   *source*  the source operand location, which unless otherwise
      specified is one of:

    +========+=======+================================================+
    | source | value | description                                    |
    +========+=======+================================================+
    | BPF_K  | 0x00  | use 32-bit 'imm' value as source operand       |
    +--------+-------+------------------------------------------------+
    | BPF_X  | 0x08  | use 'src_reg' register value as source operand |
    +--------+-------+------------------------------------------------+

                                  Table 3

   *instruction class*  the instruction class (see Instruction classes
      (Section 3.1))

4.1.  Arithmetic instructions

   BPF_ALU uses 32-bit wide operands while BPF_ALU64 uses 64-bit wide
   operands for otherwise identical operations.  The 'code' field
   encodes the operation as below, where 'src' and 'dst' refer to the
   values of the source and destination registers, respectively.

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        +==========+=======+======================================+
        | code     | value | description                          |
        +==========+=======+======================================+
        | BPF_ADD  | 0x00  | dst += src                           |
        +----------+-------+--------------------------------------+
        | BPF_SUB  | 0x10  | dst -= src                           |
        +----------+-------+--------------------------------------+
        | BPF_MUL  | 0x20  | dst *= src                           |
        +----------+-------+--------------------------------------+
        | BPF_DIV  | 0x30  | dst = (src != 0) ? (dst / src) : 0   |
        +----------+-------+--------------------------------------+
        | BPF_OR   | 0x40  | dst |= src                           |
        +----------+-------+--------------------------------------+
        | BPF_AND  | 0x50  | dst &= src                           |
        +----------+-------+--------------------------------------+
        | BPF_LSH  | 0x60  | dst <<= (src & mask)                 |
        +----------+-------+--------------------------------------+
        | BPF_RSH  | 0x70  | dst >>= (src & mask)                 |
        +----------+-------+--------------------------------------+
        | BPF_NEG  | 0x80  | dst = -src                           |
        +----------+-------+--------------------------------------+
        | BPF_MOD  | 0x90  | dst = (src != 0) ? (dst % src) : dst |
        +----------+-------+--------------------------------------+
        | BPF_XOR  | 0xa0  | dst ^= src                           |
        +----------+-------+--------------------------------------+
        | BPF_MOV  | 0xb0  | dst = src                            |
        +----------+-------+--------------------------------------+
        | BPF_ARSH | 0xc0  | sign extending dst >>= (src & mask)  |
        +----------+-------+--------------------------------------+
        | BPF_END  | 0xd0  | byte swap operations (see Byte swap  |
        |          |       | instructions (Section 4.1.1) below)  |
        +----------+-------+--------------------------------------+

                                  Table 4

   Underflow and overflow are allowed during arithmetic operations,
   meaning the 64-bit or 32-bit value will wrap.  If eBPF 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 BPF_ALU64 the value of the destination register is unchanged
   whereas for BPF_ALU the upper 32 bits of the destination register are
   zeroed.

   BPF_ADD | BPF_X | BPF_ALU means:

     dst = (u32) ((u32) dst + (u32) src)

   where '(u32)' indicates that the upper 32 bits are zeroed.

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   BPF_ADD | BPF_X | BPF_ALU64 means:

     dst = dst + src

   BPF_XOR | BPF_K | BPF_ALU means:

     dst = (u32) dst ^ (u32) imm32

   BPF_XOR | BPF_K | BPF_ALU64 means:

     dst = dst ^ imm32

   Also note that the division and modulo operations are unsigned.
   Thus, for BPF_ALU, 'imm' is first interpreted as an unsigned 32-bit
   value, whereas for BPF_ALU64, 'imm' is first sign extended to 64 bits
   and the result interpreted as an unsigned 64-bit value.  There are no
   instructions for signed division or modulo.

   Shift operations use a mask of 0x3F (63) for 64-bit operations and
   0x1F (31) for 32-bit operations.

4.1.1.  Byte swap instructions

   The byte swap instructions use an instruction class of BPF_ALU and a
   4-bit 'code' field of BPF_END.

   The byte swap instructions operate on the destination register only
   and do not use a separate source register or immediate value.

   The 1-bit source operand field in the opcode is used to select what
   byte order the operation convert from or to:

             +===========+=======+===========================+
             | source    | value | description               |
             +===========+=======+===========================+
             | BPF_TO_LE | 0x00  | convert between host byte |
             |           |       | order and little endian   |
             +-----------+-------+---------------------------+
             | BPF_TO_BE | 0x08  | convert between host byte |
             |           |       | order and big endian      |
             +-----------+-------+---------------------------+

                                  Table 5

   The 'imm' field encodes the width of the swap operations.  The
   following widths are supported: 16, 32 and 64.

   Examples:

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   BPF_ALU | BPF_TO_LE | BPF_END with imm = 16 means:

     dst = htole16(dst)

   BPF_ALU | BPF_TO_BE | BPF_END with imm = 64 means:

     dst = htobe64(dst)

4.2.  Jump instructions

   BPF_JMP32 uses 32-bit wide operands while BPF_JMP uses 64-bit wide
   operands for otherwise identical operations.  The 'code' field
   encodes the operation as below:

   +==========+=======+=====+=====================+===================+
   | code     | value | src | description         | notes             |
   +==========+=======+=====+=====================+===================+
   | BPF_JA   | 0x0   | 0x0 | PC += offset        | BPF_JMP only      |
   +----------+-------+-----+---------------------+-------------------+
   | BPF_JEQ  | 0x1   | any | PC += offset if dst |                   |
   |          |       |     | == src              |                   |
   +----------+-------+-----+---------------------+-------------------+
   | BPF_JGT  | 0x2   | any | PC += offset if dst | unsigned          |
   |          |       |     | > src               |                   |
   +----------+-------+-----+---------------------+-------------------+
   | BPF_JGE  | 0x3   | any | PC += offset if dst | unsigned          |
   |          |       |     | >= src              |                   |
   +----------+-------+-----+---------------------+-------------------+
   | BPF_JSET | 0x4   | any | PC += offset if dst |                   |
   |          |       |     | & src               |                   |
   +----------+-------+-----+---------------------+-------------------+
   | BPF_JNE  | 0x5   | any | PC += offset if dst |                   |
   |          |       |     | != src              |                   |
   +----------+-------+-----+---------------------+-------------------+
   | BPF_JSGT | 0x6   | any | PC += offset if dst | signed            |
   |          |       |     | > src               |                   |
   +----------+-------+-----+---------------------+-------------------+
   | BPF_JSGE | 0x7   | any | PC += offset if dst | signed            |
   |          |       |     | >= src              |                   |
   +----------+-------+-----+---------------------+-------------------+
   | BPF_CALL | 0x8   | 0x0 | call helper         | see Helper        |
   |          |       |     | function by address | functions         |
   |          |       |     |                     | (Section 4.2.1)   |
   +----------+-------+-----+---------------------+-------------------+
   | BPF_CALL | 0x8   | 0x1 | call PC += offset   | see Program-local |
   |          |       |     |                     | functions         |
   |          |       |     |                     | (Section 4.2.2)   |
   +----------+-------+-----+---------------------+-------------------+

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   | BPF_CALL | 0x8   | 0x2 | call helper         | see Helper        |
   |          |       |     | function by BTF ID  | functions         |
   |          |       |     |                     | (Section 4.2.1)   |
   +----------+-------+-----+---------------------+-------------------+
   | BPF_EXIT | 0x9   | 0x0 | return              | BPF_JMP only      |
   +----------+-------+-----+---------------------+-------------------+
   | BPF_JLT  | 0xa   | any | PC += offset if dst | unsigned          |
   |          |       |     | < src               |                   |
   +----------+-------+-----+---------------------+-------------------+
   | BPF_JLE  | 0xb   | any | PC += offset if dst | unsigned          |
   |          |       |     | <= src              |                   |
   +----------+-------+-----+---------------------+-------------------+
   | BPF_JSLT | 0xc   | any | PC += offset if dst | signed            |
   |          |       |     | < src               |                   |
   +----------+-------+-----+---------------------+-------------------+
   | BPF_JSLE | 0xd   | any | PC += offset if dst | signed            |
   |          |       |     | <= src              |                   |
   +----------+-------+-----+---------------------+-------------------+

                                 Table 6

   The eBPF program needs to store the return value into register R0
   before doing a BPF_EXIT.

   Example:

   BPF_JSGE | BPF_X | BPF_JMP32 (0x7e) means:

     if (s32)dst s>= (s32)src goto +offset

   where 's>=' indicates a signed '>=' comparison.

4.2.1.  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 an address
   encoded in the imm field.  The available helper functions may differ
   for each program type, but address values are unique across all
   program types.

   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.

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4.2.2.  Program-local functions

   Program-local functions are functions exposed by the same BPF program
   as the caller, and are referenced by offset from the call
   instruction, similar to BPF_JA.  A BPF_EXIT within the program-local
   function will return to the caller.

5.  Load and store instructions

   For load and store instructions (BPF_LD, BPF_LDX, BPF_ST, and
   BPF_STX), the 8-bit 'opcode' field is divided as:

               +==============+========+===================+
               | 3 bits (MSB) | 2 bits | 3 bits (LSB)      |
               +==============+========+===================+
               | mode         | size   | instruction class |
               +--------------+--------+-------------------+

                                  Table 7

   The mode modifier is one of:

      +============+=======+==================+=====================+
      | mode       | value | description      | reference           |
      | modifier   |       |                  |                     |
      +============+=======+==================+=====================+
      | BPF_IMM    | 0x00  | 64-bit immediate | 64-bit immediate    |
      |            |       | instructions     | instructions        |
      |            |       |                  | (Section 5.3)       |
      +------------+-------+------------------+---------------------+
      | BPF_ABS    | 0x20  | legacy BPF       | Legacy BPF Packet   |
      |            |       | packet access    | access instructions |
      |            |       | (absolute)       | (Section 5.4)       |
      +------------+-------+------------------+---------------------+
      | BPF_IND    | 0x40  | legacy BPF       | Legacy BPF Packet   |
      |            |       | packet access    | access instructions |
      |            |       | (indirect)       | (Section 5.4)       |
      +------------+-------+------------------+---------------------+
      | BPF_MEM    | 0x60  | regular load and | Regular load and    |
      |            |       | store operations | store operations    |
      |            |       |                  | (Section 5.1)       |
      +------------+-------+------------------+---------------------+
      | BPF_ATOMIC | 0xc0  | atomic           | Atomic operations   |
      |            |       | operations       | (Section 5.2)       |
      +------------+-------+------------------+---------------------+

                                  Table 8

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   The size modifier is one of:

             +===============+=======+=======================+
             | size modifier | value | description           |
             +===============+=======+=======================+
             | BPF_W         | 0x00  | word (4 bytes)        |
             +---------------+-------+-----------------------+
             | BPF_H         | 0x08  | half word (2 bytes)   |
             +---------------+-------+-----------------------+
             | BPF_B         | 0x10  | byte                  |
             +---------------+-------+-----------------------+
             | BPF_DW        | 0x18  | double word (8 bytes) |
             +---------------+-------+-----------------------+

                                  Table 9

5.1.  Regular load and store operations

   The BPF_MEM mode modifier is used to encode regular load and store
   instructions that transfer data between a register and memory.

   BPF_MEM | <size> | BPF_STX means:

     *(size *) (dst + offset) = src

   BPF_MEM | <size> | BPF_ST means:

     *(size *) (dst + offset) = imm32

   BPF_MEM | <size> | BPF_LDX means:

     dst = *(size *) (src + offset)

   Where size is one of: BPF_B, BPF_H, BPF_W, or BPF_DW.

5.2.  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 eBPF programs or means outside of this specification.

   All atomic operations supported by eBPF are encoded as store
   operations that use the BPF_ATOMIC mode modifier as follows:

   *  BPF_ATOMIC | BPF_W | BPF_STX for 32-bit operations

   *  BPF_ATOMIC | BPF_DW | BPF_STX for 64-bit operations

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   *  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 |
                     +=========+=======+=============+
                     | BPF_ADD | 0x00  | atomic add  |
                     +---------+-------+-------------+
                     | BPF_OR  | 0x40  | atomic or   |
                     +---------+-------+-------------+
                     | BPF_AND | 0x50  | atomic and  |
                     +---------+-------+-------------+
                     | BPF_XOR | 0xa0  | atomic xor  |
                     +---------+-------+-------------+

                                  Table 10

   BPF_ATOMIC | BPF_W | BPF_STX with 'imm' = BPF_ADD means:

     *(u32 *)(dst + offset) += src

   BPF_ATOMIC | BPF_DW | BPF_STX with 'imm' = BPF 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                 |
     +=============+==================+=============================+
     | BPF_FETCH   | 0x01             | modifier: return old value  |
     +-------------+------------------+-----------------------------+
     | BPF_XCHG    | 0xe0 | BPF_FETCH | atomic exchange             |
     +-------------+------------------+-----------------------------+
     | BPF_CMPXCHG | 0xf0 | BPF_FETCH | atomic compare and exchange |
     +-------------+------------------+-----------------------------+

                                 Table 11

   The BPF_FETCH modifier is optional for simple atomic operations, and
   always set for the complex atomic operations.  If the BPF_FETCH flag
   is set, then the operation also overwrites src with the value that
   was in memory before it was modified.

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   The BPF_XCHG operation atomically exchanges src with the value
   addressed by dst + offset.

   The BPF_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.

5.3.  64-bit immediate instructions

   Instructions with the BPF_IMM 'mode' modifier use the wide
   instruction encoding defined in Instruction encoding (Section 3), and
   use the 'src' field of the basic instruction to hold an opcode
   subtype.

   The following table defines a set of BPF_IMM | BPF_DW | BPF_LD
   instructions with opcode subtypes in the 'src' field, using new terms
   such as "map" defined further below:

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    +============+======+===+========================+========+=======+
    |opcode      |opcode|src|pseudocode              |imm type|dst    |
    |construction|      |   |                        |        |type   |
    +============+======+===+========================+========+=======+
    |BPF_IMM |   |0x18  |0x0|dst = imm64             |integer |integer|
    |BPF_DW |    |      |   |                        |        |       |
    |BPF_LD      |      |   |                        |        |       |
    +------------+------+---+------------------------+--------+-------+
    |BPF_IMM |   |0x18  |0x1|dst = map_by_fd(imm)    |map fd  |map    |
    |BPF_DW |    |      |   |                        |        |       |
    |BPF_LD      |      |   |                        |        |       |
    +------------+------+---+------------------------+--------+-------+
    |BPF_IMM |   |0x18  |0x2|dst =                   |map fd  |data   |
    |BPF_DW |    |      |   |map_val(map_by_fd(imm)) |        |pointer|
    |BPF_LD      |      |   |+ next_imm              |        |       |
    +------------+------+---+------------------------+--------+-------+
    |BPF_IMM |   |0x18  |0x3|dst = var_addr(imm)     |variable|data   |
    |BPF_DW |    |      |   |                        |id      |pointer|
    |BPF_LD      |      |   |                        |        |       |
    +------------+------+---+------------------------+--------+-------+
    |BPF_IMM |   |0x18  |0x4|dst = code_addr(imm)    |integer |code   |
    |BPF_DW |    |      |   |                        |        |pointer|
    |BPF_LD      |      |   |                        |        |       |
    +------------+------+---+------------------------+--------+-------+
    |BPF_IMM |   |0x18  |0x5|dst = map_by_idx(imm)   |map     |map    |
    |BPF_DW |    |      |   |                        |index   |       |
    |BPF_LD      |      |   |                        |        |       |
    +------------+------+---+------------------------+--------+-------+
    |BPF_IMM |   |0x18  |0x6|dst =                   |map     |data   |
    |BPF_DW |    |      |   |map_val(map_by_idx(imm))|index   |pointer|
    |BPF_LD      |      |   |+ next_imm              |        |       |
    +------------+------+---+------------------------+--------+-------+

                                  Table 12

   where

   *  map_by_fd(imm) means to convert a 32-bit file descriptor into an
      address of a map (see Maps (Section 5.3.1))

   *  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 5.3.2)) with a given id

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   *  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

5.3.1.  Maps

   Maps are shared memory regions accessible by eBPF 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.

5.3.2.  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.

5.4.  Legacy BPF Packet access instructions

   eBPF previously introduced special instructions for access to packet
   data that were carried over from classic BPF.  However, these
   instructions are deprecated and should no longer be used.

6.  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, Christoph Hellwig, Jose
   E.  Marchesi, Kosuke Fujimoto, Shahab Vahedi, Tiezhu Yang, and Zheng
   Yejian, with review and suggestions by many others including Alan
   Jowett, Alexei Starovoitov, Andrii Nakryiko, Daniel Borkmann, David
   Vernet, Jim Harris, Quentin Monnet, Song Liu, Shung-Hsi Yu, Stanislav
   Fomichev, and Yonghong Song.

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7.  Appendix

   For reference, the following table lists opcodes in order by value.

   +========+=====+======+==========================+===============+
   | opcode | src | imm  |description               | reference     |
   +========+=====+======+==========================+===============+
   | 0x00   | 0x0 | any  |(additional immediate     | 64-bit        |
   |        |     |      |value)                    | immediate     |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5.3) |
   +--------+-----+------+--------------------------+---------------+
   | 0x04   | 0x0 | any  |dst = (u32)((u32)dst +    | Arithmetic    |
   |        |     |      |(u32)imm)                 | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x05   | 0x0 | 0x00 |goto +offset              | Jump          |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x07   | 0x0 | any  |dst += imm                | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x0c   | any | 0x00 |dst = (u32)((u32)dst +    | Arithmetic    |
   |        |     |      |(u32)src)                 | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x0f   | any | 0x00 |dst += src                | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x14   | 0x0 | any  |dst = (u32)((u32)dst -    | Arithmetic    |
   |        |     |      |(u32)imm)                 | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x15   | 0x0 | any  |if dst == imm goto        | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x16   | 0x0 | any  |if (u32)dst == imm goto   | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x17   | 0x0 | any  |dst -= imm                | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+

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   | 0x18   | 0x0 | any  |dst = imm64               | 64-bit        |
   |        |     |      |                          | immediate     |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5.3) |
   +--------+-----+------+--------------------------+---------------+
   | 0x18   | 0x1 | any  |dst = map_by_fd(imm)      | 64-bit        |
   |        |     |      |                          | immediate     |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5.3) |
   +--------+-----+------+--------------------------+---------------+
   | 0x18   | 0x2 | any  |dst =                     | 64-bit        |
   |        |     |      |mva(map_by_fd(imm)) +     | immediate     |
   |        |     |      |next_imm                  | instructions  |
   |        |     |      |                          | (Section 5.3) |
   +--------+-----+------+--------------------------+---------------+
   | 0x18   | 0x3 | any  |dst = variable_addr(imm)  | 64-bit        |
   |        |     |      |                          | immediate     |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5.3) |
   +--------+-----+------+--------------------------+---------------+
   | 0x18   | 0x4 | any  |dst = code_addr(imm)      | 64-bit        |
   |        |     |      |                          | immediate     |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5.3) |
   +--------+-----+------+--------------------------+---------------+
   | 0x18   | 0x5 | any  |dst = map_by_idx(imm)     | 64-bit        |
   |        |     |      |                          | immediate     |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5.3) |
   +--------+-----+------+--------------------------+---------------+
   | 0x18   | 0x6 | any  |dst =                     | 64-bit        |
   |        |     |      |mva(map_by_idx(imm)) +    | immediate     |
   |        |     |      |next_imm                  | instructions  |
   |        |     |      |                          | (Section 5.3) |
   +--------+-----+------+--------------------------+---------------+
   | 0x1c   | any | 0x00 |dst = (u32)((u32)dst -    | Arithmetic    |
   |        |     |      |(u32)src)                 | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x1d   | any | 0x00 |if dst == src goto        | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x1e   | any | 0x00 |if (u32)dst == (u32)src   | Jump          |
   |        |     |      |goto +offset              | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x1f   | any | 0x00 |dst -= src                | Arithmetic    |

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   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x20   | any | any  |(deprecated,              | Legacy BPF    |
   |        |     |      |implementation-specific)  | Packet access |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5.4) |
   +--------+-----+------+--------------------------+---------------+
   | 0x24   | 0x0 | any  |dst = (u32)(dst * imm)    | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x25   | 0x0 | any  |if dst > imm goto         | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x26   | 0x0 | any  |if (u32)dst > imm goto    | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x27   | 0x0 | any  |dst *= imm                | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x28   | any | any  |(deprecated,              | Legacy BPF    |
   |        |     |      |implementation-specific)  | Packet access |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5.4) |
   +--------+-----+------+--------------------------+---------------+
   | 0x2c   | any | 0x00 |dst = (u32)(dst * src)    | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x2d   | any | 0x00 |if dst > src goto         | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x2e   | any | 0x00 |if (u32)dst > (u32)src    | Jump          |
   |        |     |      |goto +offset              | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x2f   | any | 0x00 |dst *= src                | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x30   | any | any  |(deprecated,              | Legacy BPF    |
   |        |     |      |implementation-specific)  | Packet access |
   |        |     |      |                          | instructions  |

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   |        |     |      |                          | (Section 5.4) |
   +--------+-----+------+--------------------------+---------------+
   | 0x34   | 0x0 | any  |dst = (u32)((imm != 0) ?  | Arithmetic    |
   |        |     |      |(dst / imm) : 0)          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x35   | 0x0 | any  |if dst >= imm goto        | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x36   | 0x0 | any  |if (u32)dst >= imm goto   | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x37   | 0x0 | any  |dst = (imm != 0) ? (dst   | Arithmetic    |
   |        |     |      |/ imm) : 0                | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x38   | any | any  |(deprecated,              | Legacy BPF    |
   |        |     |      |implementation-specific)  | Packet access |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5.4) |
   +--------+-----+------+--------------------------+---------------+
   | 0x3c   | any | 0x00 |dst = (u32)((imm != 0) ?  | Arithmetic    |
   |        |     |      |(dst / src) : 0)          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x3d   | any | 0x00 |if dst >= src goto        | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x3e   | any | 0x00 |if (u32)dst >= (u32)src   | Jump          |
   |        |     |      |goto +offset              | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x3f   | any | 0x00 |dst = (src !+ 0) ? (dst   | Arithmetic    |
   |        |     |      |/ src) : 0                | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x40   | any | any  |(deprecated,              | Legacy BPF    |
   |        |     |      |implementation-specific)  | Packet access |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5.4) |
   +--------+-----+------+--------------------------+---------------+
   | 0x44   | 0x0 | any  |dst = (u32)(dst | imm)    | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+

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   | 0x45   | 0x0 | any  |if dst & imm goto         | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x46   | 0x0 | any  |if (u32)dst & imm goto    | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x47   | 0x0 | any  |dst |= imm                | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x48   | any | any  |(deprecated,              | Legacy BPF    |
   |        |     |      |implementation-specific)  | Packet access |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5.4) |
   +--------+-----+------+--------------------------+---------------+
   | 0x4c   | any | 0x00 |dst = (u32)(dst | src)    | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x4d   | any | 0x00 |if dst & src goto         | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x4e   | any | 0x00 |if (u32)dst & (u32)src    | Jump          |
   |        |     |      |goto +offset              | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x4f   | any | 0x00 |dst |= src                | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x50   | any | any  |(deprecated,              | Legacy BPF    |
   |        |     |      |implementation-specific)  | Packet access |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5.4) |
   +--------+-----+------+--------------------------+---------------+
   | 0x54   | 0x0 | any  |dst = (u32)(dst & imm)    | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x55   | 0x0 | any  |if dst != imm goto        | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x56   | 0x0 | any  |if (u32)dst != imm goto   | Jump          |
   |        |     |      |+offset                   | instructions  |

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   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x57   | 0x0 | any  |dst &= imm                | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x58   | any | any  |(deprecated,              | Legacy BPF    |
   |        |     |      |implementation-specific)  | Packet access |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5.4) |
   +--------+-----+------+--------------------------+---------------+
   | 0x5c   | any | 0x00 |dst = (u32)(dst & src)    | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x5d   | any | 0x00 |if dst != src goto        | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x5e   | any | 0x00 |if (u32)dst != (u32)src   | Jump          |
   |        |     |      |goto +offset              | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x5f   | any | 0x00 |dst &= src                | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x61   | any | 0x00 |dst = *(u32 *)(src +      | Load and      |
   |        |     |      |offset)                   | store         |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5)   |
   +--------+-----+------+--------------------------+---------------+
   | 0x62   | 0x0 | any  |*(u32 *)(dst + offset) =  | Load and      |
   |        |     |      |imm                       | store         |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5)   |
   +--------+-----+------+--------------------------+---------------+
   | 0x63   | any | 0x00 |*(u32 *)(dst + offset) =  | Load and      |
   |        |     |      |src                       | store         |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5)   |
   +--------+-----+------+--------------------------+---------------+
   | 0x64   | 0x0 | any  |dst = (u32)(dst << imm)   | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x65   | 0x0 | any  |if dst s> imm goto        | Jump          |
   |        |     |      |+offset                   | instructions  |

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   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x66   | 0x0 | any  |if (s32)dst s> (s32)imm   | Jump          |
   |        |     |      |goto +offset              | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x67   | 0x0 | any  |dst <<= imm               | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x69   | any | 0x00 |dst = *(u16 *)(src +      | Load and      |
   |        |     |      |offset)                   | store         |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5)   |
   +--------+-----+------+--------------------------+---------------+
   | 0x6a   | 0x0 | any  |*(u16 *)(dst + offset) =  | Load and      |
   |        |     |      |imm                       | store         |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5)   |
   +--------+-----+------+--------------------------+---------------+
   | 0x6b   | any | 0x00 |*(u16 *)(dst + offset) =  | Load and      |
   |        |     |      |src                       | store         |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5)   |
   +--------+-----+------+--------------------------+---------------+
   | 0x6c   | any | 0x00 |dst = (u32)(dst << src)   | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x6d   | any | 0x00 |if dst s> src goto        | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x6e   | any | 0x00 |if (s32)dst s> (s32)src   | Jump          |
   |        |     |      |goto +offset              | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x6f   | any | 0x00 |dst <<= src               | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x71   | any | 0x00 |dst = *(u8 *)(src +       | Load and      |
   |        |     |      |offset)                   | store         |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5)   |
   +--------+-----+------+--------------------------+---------------+
   | 0x72   | 0x0 | any  |*(u8 *)(dst + offset) =   | Load and      |
   |        |     |      |imm                       | store         |

Thaler                   Expires 11 January 2024               [Page 23]
Internet-Draft                  eBPF ISA                       July 2023

   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5)   |
   +--------+-----+------+--------------------------+---------------+
   | 0x73   | any | 0x00 |*(u8 *)(dst + offset) =   | Load and      |
   |        |     |      |src                       | store         |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5)   |
   +--------+-----+------+--------------------------+---------------+
   | 0x74   | 0x0 | any  |dst = (u32)(dst >> imm)   | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x75   | 0x0 | any  |if dst s>= imm goto       | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x76   | 0x0 | any  |if (s32)dst s>= (s32)imm  | Jump          |
   |        |     |      |goto +offset              | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x77   | 0x0 | any  |dst >>= imm               | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x79   | any | 0x00 |dst = *(u64 *)(src +      | Load and      |
   |        |     |      |offset)                   | store         |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5)   |
   +--------+-----+------+--------------------------+---------------+
   | 0x7a   | 0x0 | any  |*(u64 *)(dst + offset) =  | Load and      |
   |        |     |      |imm                       | store         |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5)   |
   +--------+-----+------+--------------------------+---------------+
   | 0x7b   | any | 0x00 |*(u64 *)(dst + offset) =  | Load and      |
   |        |     |      |src                       | store         |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 5)   |
   +--------+-----+------+--------------------------+---------------+
   | 0x7c   | any | 0x00 |dst = (u32)(dst >> src)   | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x7d   | any | 0x00 |if dst s>= src goto       | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x7e   | any | 0x00 |if (s32)dst s>= (s32)src  | Jump          |

Thaler                   Expires 11 January 2024               [Page 24]
Internet-Draft                  eBPF ISA                       July 2023

   |        |     |      |goto +offset              | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x7f   | any | 0x00 |dst >>= src               | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x84   | 0x0 | 0x00 |dst = (u32)-dst           | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x85   | 0x0 | any  |call platform-agnostic    | Helper        |
   |        |     |      |helper function imm       | functions     |
   |        |     |      |                          | (Section      |
   |        |     |      |                          | 4.2.1)        |
   +--------+-----+------+--------------------------+---------------+
   | 0x85   | 0x1 | any  |call PC += offset         | Program-local |
   |        |     |      |                          | functions     |
   |        |     |      |                          | (Section      |
   |        |     |      |                          | 4.2.2)        |
   +--------+-----+------+--------------------------+---------------+
   | 0x85   | 0x2 | any  |call platform-specific    | Helper        |
   |        |     |      |helper function imm       | functions     |
   |        |     |      |                          | (Section      |
   |        |     |      |                          | 4.2.1)        |
   +--------+-----+------+--------------------------+---------------+
   | 0x87   | 0x0 | 0x00 |dst = -dst                | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x94   | 0x0 | any  |dst = (u32)((imm != 0) ?  | Arithmetic    |
   |        |     |      |(dst % imm) : dst)        | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x95   | 0x0 | 0x00 |return                    | Jump          |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0x97   | 0x0 | any  |dst = (imm != 0) ? (dst   | Arithmetic    |
   |        |     |      |% imm) : dst              | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x9c   | any | 0x00 |dst = (u32)((src != 0) ?  | Arithmetic    |
   |        |     |      |(dst % src) : dst)        | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0x9f   | any | 0x00 |dst = (src != 0) ? (dst   | Arithmetic    |
   |        |     |      |% src) : dst              | instructions  |

Thaler                   Expires 11 January 2024               [Page 25]
Internet-Draft                  eBPF ISA                       July 2023

   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0xa4   | 0x0 | any  |dst = (u32)(dst ^ imm)    | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0xa5   | 0x0 | any  |if dst < imm goto         | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xa6   | 0x0 | any  |if (u32)dst < imm goto    | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xa7   | 0x0 | any  |dst ^= imm                | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0xac   | any | 0x00 |dst = (u32)(dst ^ src)    | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0xad   | any | 0x00 |if dst < src goto         | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xae   | any | 0x00 |if (u32)dst < (u32)src    | Jump          |
   |        |     |      |goto +offset              | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xaf   | any | 0x00 |dst ^= src                | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0xb4   | 0x0 | any  |dst = (u32) imm           | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0xb5   | 0x0 | any  |if dst <= imm goto        | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xa6   | 0x0 | any  |if (u32)dst <= imm goto   | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xb7   | 0x0 | any  |dst = imm                 | Arithmetic    |
   |        |     |      |                          | instructions  |

Thaler                   Expires 11 January 2024               [Page 26]
Internet-Draft                  eBPF ISA                       July 2023

   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0xbc   | any | 0x00 |dst = (u32) src           | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0xbd   | any | 0x00 |if dst <= src goto        | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xbe   | any | 0x00 |if (u32)dst <= (u32)src   | Jump          |
   |        |     |      |goto +offset              | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xbf   | any | 0x00 |dst = src                 | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0xc3   | any | 0x00 |lock *(u32 *)(dst +       | Atomic        |
   |        |     |      |offset) += src            | operations    |
   |        |     |      |                          | (Section 5.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xc3   | any | 0x01 |lock:                     | Atomic        |
   |        |     |      |                          | operations    |
   |        |     |      |    *(u32 *)(dst + offset) += src| (Section 5.2) |
   |        |     |      |    src = *(u32 *)(dst + offset)|               |
   +--------+-----+------+--------------------------+---------------+
   | 0xc3   | any | 0x40 |*(u32 *)(dst +            | Atomic        |
   |        |     |      |offset) |= src            | operations    |
   |        |     |      |                          | (Section 5.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xc3   | any | 0x41 |lock:                     | Atomic        |
   |        |     |      |                          | operations    |
   |        |     |      |    *(u32 *)(dst + offset) |= src| (Section 5.2) |
   |        |     |      |    src = *(u32 *)(dst + offset)|               |
   +--------+-----+------+--------------------------+---------------+
   | 0xc3   | any | 0x50 |*(u32 *)(dst + offset)    | Atomic        |
   |        |     |      |&= src                    | operations    |
   |        |     |      |                          | (Section 5.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xc3   | any | 0x51 |lock:                     | Atomic        |
   |        |     |      |                          | operations    |
   |        |     |      |    *(u32 *)(dst + offset) &= src| (Section 5.2) |
   |        |     |      |    src = *(u32 *)(dst + offset)|               |
   +--------+-----+------+--------------------------+---------------+
   | 0xc3   | any | 0xa0 |*(u32 *)(dst + offset)    | Atomic        |
   |        |     |      |^= src                    | operations    |
   |        |     |      |                          | (Section 5.2) |

Thaler                   Expires 11 January 2024               [Page 27]
Internet-Draft                  eBPF ISA                       July 2023

   +--------+-----+------+--------------------------+---------------+
   | 0xc3   | any | 0xa1 |lock:                     | Atomic        |
   |        |     |      |                          | operations    |
   |        |     |      |    *(u32 *)(dst + offset) ^= src| (Section 5.2) |
   |        |     |      |    src = *(u32 *)(dst + offset)|               |
   +--------+-----+------+--------------------------+---------------+
   | 0xc3   | any | 0xe1 |lock:                     | Atomic        |
   |        |     |      |                          | operations    |
   |        |     |      |    temp = *(u32 *)(dst + offset)| (Section 5.2) |
   |        |     |      |    *(u32 *)(dst + offset) = src|               |
   |        |     |      |    src = temp            |               |
   +--------+-----+------+--------------------------+---------------+
   | 0xc3   | any | 0xf1 |lock:                     | Atomic        |
   |        |     |      |                          | operations    |
   |        |     |      |    temp = *(u32 *)(dst + offset)| (Section 5.2) |
   |        |     |      |    if *(u32)(dst + offset) == R0|               |
   |        |     |      |       *(u32)(dst + offset) = src|               |
   |        |     |      |    R0 = temp             |               |
   +--------+-----+------+--------------------------+---------------+
   | 0xc4   | 0x0 | any  |dst = (u32)(dst s>> imm)  | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0xc5   | 0x0 | any  |if dst s< imm goto        | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xc6   | 0x0 | any  |if (s32)dst s< (s32)imm   | Jump          |
   |        |     |      |goto +offset              | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xc7   | 0x0 | any  |dst s>>= imm              | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0xcc   | any | 0x00 |dst = (u32)(dst s>> src)  | Arithmetic    |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0xcd   | any | 0x00 |if dst s< src goto        | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xce   | any | 0x00 |if (s32)dst s< (s32)src   | Jump          |
   |        |     |      |goto +offset              | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xcf   | any | 0x00 |dst s>>= src              | Arithmetic    |

Thaler                   Expires 11 January 2024               [Page 28]
Internet-Draft                  eBPF ISA                       July 2023

   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section 4.1) |
   +--------+-----+------+--------------------------+---------------+
   | 0xd4   | 0x0 | 0x10 |dst = htole16(dst)        | Byte swap     |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section      |
   |        |     |      |                          | 4.1.1)        |
   +--------+-----+------+--------------------------+---------------+
   | 0xd4   | 0x0 | 0x20 |dst = htole32(dst)        | Byte swap     |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section      |
   |        |     |      |                          | 4.1.1)        |
   +--------+-----+------+--------------------------+---------------+
   | 0xd4   | 0x0 | 0x40 |dst = htole64(dst)        | Byte swap     |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section      |
   |        |     |      |                          | 4.1.1)        |
   +--------+-----+------+--------------------------+---------------+
   | 0xd5   | 0x0 | any  |if dst s<= imm goto       | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xd6   | 0x0 | any  |if (s32)dst s<= (s32)imm  | Jump          |
   |        |     |      |goto +offset              | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xdb   | any | 0x00 |lock *(u64 *)(dst +       | Atomic        |
   |        |     |      |offset) += src            | operations    |
   |        |     |      |                          | (Section 5.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xdb   | any | 0x01 |lock:                     | Atomic        |
   |        |     |      |                          | operations    |
   |        |     |      |    *(u64 *)(dst + offset) += src| (Section 5.2) |
   |        |     |      |    src = *(u64 *)(dst + offset)|               |
   +--------+-----+------+--------------------------+---------------+
   | 0xdb   | any | 0x40 |*(u64 *)(dst +            | Atomic        |
   |        |     |      |offset) |= src            | operations    |
   |        |     |      |                          | (Section 5.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xdb   | any | 0x41 |lock:                     | Atomic        |
   |        |     |      |                          | operations    |
   |        |     |      |    *(u64 *)(dst + offset) |= src| (Section 5.2) |
   |        |     |      |    lock src = *(u64 *)(dst + offset)|               |
   +--------+-----+------+--------------------------+---------------+
   | 0xdb   | any | 0x50 |*(u64 *)(dst + offset)    | Atomic        |
   |        |     |      |&= src                    | operations    |
   |        |     |      |                          | (Section 5.2) |
   +--------+-----+------+--------------------------+---------------+

Thaler                   Expires 11 January 2024               [Page 29]
Internet-Draft                  eBPF ISA                       July 2023

   | 0xdb   | any | 0x51 |lock:                     | Atomic        |
   |        |     |      |                          | operations    |
   |        |     |      |    *(u64 *)(dst + offset) &= src| (Section 5.2) |
   |        |     |      |    src = *(u64 *)(dst + offset)|               |
   +--------+-----+------+--------------------------+---------------+
   | 0xdb   | any | 0xa0 |*(u64 *)(dst + offset)    | Atomic        |
   |        |     |      |^= src                    | operations    |
   |        |     |      |                          | (Section 5.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xdb   | any | 0xa1 |lock:                     | Atomic        |
   |        |     |      |                          | operations    |
   |        |     |      |    *(u64 *)(dst + offset) ^= src| (Section 5.2) |
   |        |     |      |    src = *(u64 *)(dst + offset)|               |
   +--------+-----+------+--------------------------+---------------+
   | 0xdb   | any | 0xe1 |lock:                     | Atomic        |
   |        |     |      |                          | operations    |
   |        |     |      |    temp = *(u64 *)(dst + offset)| (Section 5.2) |
   |        |     |      |    *(u64 *)(dst + offset) = src|               |
   |        |     |      |    src = temp            |               |
   +--------+-----+------+--------------------------+---------------+
   | 0xdb   | any | 0xf1 |lock:                     | Atomic        |
   |        |     |      |                          | operations    |
   |        |     |      |    temp = *(u64 *)(dst + offset)| (Section 5.2) |
   |        |     |      |    if *(u64)(dst + offset) == R0|               |
   |        |     |      |       *(u64)(dst + offset) = src|               |
   |        |     |      |    R0 = temp             |               |
   +--------+-----+------+--------------------------+---------------+
   | 0xdc   | 0x0 | 0x10 |dst = htobe16(dst)        | Byte swap     |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section      |
   |        |     |      |                          | 4.1.1)        |
   +--------+-----+------+--------------------------+---------------+
   | 0xdc   | 0x0 | 0x20 |dst = htobe32(dst)        | Byte swap     |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section      |
   |        |     |      |                          | 4.1.1)        |
   +--------+-----+------+--------------------------+---------------+
   | 0xdc   | 0x0 | 0x40 |dst = htobe64(dst)        | Byte swap     |
   |        |     |      |                          | instructions  |
   |        |     |      |                          | (Section      |
   |        |     |      |                          | 4.1.1)        |
   +--------+-----+------+--------------------------+---------------+
   | 0xdd   | any | 0x00 |if dst s<= src goto       | Jump          |
   |        |     |      |+offset                   | instructions  |
   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+
   | 0xde   | any | 0x00 |if (s32)dst s<= (s32)src  | Jump          |
   |        |     |      |goto +offset              | instructions  |

Thaler                   Expires 11 January 2024               [Page 30]
Internet-Draft                  eBPF ISA                       July 2023

   |        |     |      |                          | (Section 4.2) |
   +--------+-----+------+--------------------------+---------------+

                                  Table 13

Author's Address

   Dave Thaler (editor)
   Microsoft
   Redmond, WA 98052
   United States of America
   Email: dthaler@microsoft.com

Thaler                   Expires 11 January 2024               [Page 31]