Reference Filecoin VM implementation (v2; dev)

This repository contains the reference implementation of the Filecoin VM (specs). It is written in Rust, and intended to be integrated via FFI into non-Rust clients (e.g. Lotus, Fuhon), or directly into Rust clients (e.g. Forest). FFI bindings for Go are provided in-repo, and developers are encouraged to contribute bindings for other languages.

Build requirements

• The current MSRV (Minimum Supported Rust Version) is 1.58.1 (stable). A working version is tracked in rust-toolchain (this is picked up by rustup automatically).
• Install rustup.

Build instructions

$ git clone https://github.com/filecoin-project/ref-fvm.git
$ cd fvm
$ rustup target add wasm32-unknown-unknown
$ make

Code structure

Here's what you'll find in each directory:

• /fvm
  • The core of the Filecoin Virtual Machine. The key concepts are:
    • Machine: an instantiation of the machine, anchored at a specific state root and epoch, ready to intake messages to be applied.
    • Executor: an object to execute messages on a Machine.
    • CallManager: tracks and manages the call stack for a given message.
    • Invocation container (conceptual layer, not explicitly appearing in code): the WASM instance + sandbox under which a given actor in the call stack runs.
    • Kernel: the environment attached to an invocation container for external interactions.
  • There are two API boundaries in the system:
    1. the boundary between the actor code and the Kernel, which is traversed by invoking Syscalls.
    2. the boundary between the FVM and the host node, represented by Externs.
  • Some parts of the FVM are based on the Forest implementation.
• /sdk
  • Reference SDK implementation to write Filecoin native actors, used by the canonical built-in actors through the Actors FVM Runtime shim.
  • User-defined FVM actors written in Rust can also use this SDK, although it is currently quite rough around the edges. In the next weeks, we expect to sweeten it for improved developer experience.
  • Alternative SDKs will emerge in the community. We also expect community teams to develop SDKs in other WASM-compilable languages such as Swift, Kotlin (using Kotlin Native), and even Go (via the TinyGo compiler).
• /shared
  • A crate of core types and primitives shared between the FVM and the SDK.
• /ipld
  • IPLD libraries. Some of which are based on, and adapted from, the Forest implementation.
• /testing/conformance
  • Contains the test vector runner, as well as benchmarking utilities on top of it.
  • The conformance test runner feeds the test vector corpus located at https://github.com/filecoin-project/fvm-test-vectors into ref-fvm, in order to validate spec conformance.
  • The benchmarking utilities use the criterion Rust library to measure the performance and overhead of ref-fvm across various facets.
  • Instructions
    • To run a specific test vector, run VECTOR=test-vectors/corpus/specs_actors_v6/REST_OF_TEST_VECTOR.json cargo test -- conformance --nocapture
    • To bench a specific test vector, run VECTOR=test-vectors/corpus/specs_actors_v6/REST_OF_TEST_VECTOR.json cargo bench -- conformance --nocapture
    • To bench the system's overhead for the setup of the machine for a given test vector, run VECTOR=test-vectors/corpus/specs_actors_v6/REST_OF_TEST_VECTOR.json cargo bench -- overhead --nocapture. Note that the vector choice doesn't matter much, because the Machine initialization procedure is identicall for all vectors.
    • To get a perf flamegraph, run CARGO_PROFILE_BENCH_DEBUG=true VECTOR=testing/conformance/test-vectors/corpus/specs_actors_v6/REST_OF_TEST_VECTOR.json cargo flamegraph --bench bench_conformance -- --nocapture. The output SVG will be in flamegraph.svg.
  • Overhead measurement scenarios. There are two overhead measurement scenarios included.
    1. bench_init_only: measure the overhead of running the benchmark itself, it doesn't send any messages to the FVM to process.
    2. bench_500_simple_state_access: measures the overhead of calling the pubkey_address method on an account actor 500 times, this is the most lightweight message possible to send that actually executes actor logic (unlike a bare send).
  • Disclaimers
    • Benchmarks are currently very slow to run, setup and teardown. This is due to using default WASM cache, and will be fixed soon.

Maturity roadmap

v1: FVM running built-in actors (Milestone 1 of the FVM development roadmap)

• Alpha:
  • Declared when: all test vectors passing, integrated into Lotus via FFI.
  • Focus: theoretical correctness.
• Beta:
  • Declared when: all the above + syncing mainnet consistently, keeping up with chain consistently, i.e. when Phase 0 from the FVM milestone roadmap is reached.
  • Focus: production-readiness, performance, live consensus correctness.
• RC:
  • Declared when: all the above + integrated into a second client (likely Forest), successfully syncing mainnet on all.
  • Focus: pre-mainnet preparations.
• Final:
  • Declared when: FVM v1 is securing mainnet, i.e. when Milestone 1 from the FVM development roadmap is reached.

v2: Fully-programmable FVM (Milestone 2 of the FVM development roadmap)

• Alpha:
  • Declared when: all functionality implemented, 70%+ test coverage, integrated into Lotus via FFI.
  • Focus: feature completeness.
• Beta:
  • Declared when: testnets deployed (user and automatic), running successfully for 1 week.
  • Focus: testing and hardening.
• RC:
  • Declared when: code audited; network-upgrade releases ready for all Filecoin clients.
  • Focus: pre-mainnet preparations.
• Final:
  • Declared when: FVM v2 is operating mainnet, i.e. when Milestone 2 from the FVM development roadmap is reached.

License

Dual-licensed: MIT, Apache Software License v2, by way of the Permissive License Stack.

actors and vm forked from ChainSafe/forest commit: 73e8f95a108902c6bef44ee359a8478663844e5b