Upgrading Risc0

There are 4 parts to this process:

upgrading r0vm and rust toolchain,
upgrading Rust cargo dependencies,
upgrading Risc0 Ethereum contracts, and
generating new Guest ID using Docker.

Deciding which parts need updating will mainly depend if Risc0 has issued a patch, minor or major version bump. Quite naturally, a major version bump will require updating all 4 parts, however minor or patch will most likely require updating toolchain and Rust cargo dependencies, and generating a new Guest ID using Docker.

In what follows, all paths are relative to the project's root.

Please note the upgrade process should be done in the order specified below.

Upgrade r0vm and rust toolchain

Risc0 action - .github/actions/risc0/action.yml

inputs:
  version:
    description: 'Version of r0vm to install'
    default: 2.0.0 # bump r0vm version which usually corresponds to overall risc0 version
    required: false
  rust_version:
    description: 'Version of Rust toolchain for building guest images'
    default: 1.81.0 # bump Rust toolchain version which usually changes very rarely
    required: false

Ansible config for deployed provers - ansible/group_vars/all.yml

vlayer_risc0_version: '2.0.0'

Post-release test scripts - bash/test-release-local-prover.sh and bash/test-release-remote-prover.sh

echo "::group::risczero installation"
curl -L https://risczero.com/install | bash
export PATH="$PATH:~/.risc0/bin"
export PATH="$PATH:~/.cargo/bin"
rzup install r0vm 2.0.0
rzup install rust 1.81.0
rzup show
echo "::endgroup::"

Nightly Dockerfiles - docker/call_server/Dockerfile.nightly and docker/chain_worker/Dockerfile.nightly

RUN curl -L https://github.com/risc0/risc0/releases/download/v2.0.0/cargo-risczero-x86_64-unknown-linux-gnu.tgz -o cargo-risczero-x86_64-unknown-linux-gnu.tgz

Nix flake - nix/risc0.nix

This is a two-step process. First, change/add new Risc0 release like so:

let
releases = {
  "2.0.0" = {
    "aarch64-darwin" = {
      arch = "aarch64-apple-darwin";
      hash = pkgs.lib.fakeHash;
    };
  };
  # rest of the file
};
in
rec {
  default = risc0."2.0.0";
  inherit (package "2.0.0") "2.0.0";
  # rest of the file
}

Next, run from the project root and get the actual hash value for the new package:

$ nix develop
error: hash mismatch in fixed-output derivation '/nix/store/z82gnv3n7z1js3s33zrnq25kafdl82pk-cargo-risczero-aarch64-apple-darwin.tgz.drv':
         specified: sha256-AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA=
            got:    sha256-d/gQVXK+WAPTGRnx8Fw3XTWe6oKPw8FsLK7VNxC9aF8=
error: 1 dependencies of derivation '/nix/store/z45x6ixixxi6wrvsg29p9r8g6p2546qy-cargo-risczero-v2.0.0.drv' failed to build
error: 1 dependencies of derivation '/nix/store/nl0wkkhzm2zh7f0n6cmd2s7ismc5bm33-vlayer-env.drv' failed to build

And copy the actual hash value (got in the snippet above) into nix/risc0.nix file:

let
releases = {
  "2.0.0" = {
    "aarch64-darwin" = {
      arch = "aarch64-apple-darwin";
      hash = "sha256-d/gQVXK+WAPTGRnx8Fw3XTWe6oKPw8FsLK7VNxC9aF8=";
    };
  };
  # rest of the file

Update Risc0 requirements in the book in /appendix/contributing/rust.md

Upgrade Rust cargo dependencies

In this step of the upgrade process, as with any version bump of a Rust dependency, it may so happen that just a bump is not enough and API usage needs to be updated too. Bear that in mind when updating and experiencing compilation errors.

Main project manifest - Cargo.toml

We leave out risc0-build-ethereum unless there was a major Risc0 version bump that forced Ethereum contracts update, in which case we will come back to it in the next step of the upgrade process.

# ...
risc0-build = "=2.0.1";
risc0-build-ethereum = { git = "https://github.com/vlayer-xyz/risc0-ethereum.git", rev = "12f4a76616bdc31108fc585c4a0ce7ebd97059fd" }
risc0-zkp = { version = "=2.0.0", default-features = false }
risc0-zkvm = "=2.0.0"
bonsai-sdk = "=1.4.0"

Guests manifests - rust/guest_wrapper/risc0_call_guest/Cargo.toml and rust/guest_wrapper/risc0_chain_guest/Cargo.toml

# ...
risc0-zkvm = { version = "=2.0.0", default-features = false, features = ["std", "unstable"] }
risc0-zkvm-platform = { version = "=2.0.1", features = [ "rust-runtime", "export-getrandom", "sys-getenv" ] }

Risc0 VM benchmarks - rust/zkvm-benchmarks/runner/risc0_guest/Cargo.toml

# ...
risc0-zkvm = { version = "=2.0.0", default-features = false, features = ["std", "unstable"] }

(Optional) Upgrade Risc0 Ethereum contracts

If there was a major version bump, the project is likely failing with a compilation error when trying to build risc0-build-ethereum crate. In this case, you will need to upgrade our risc0-ethereum fork to the desired Risc0 release version.

Upgrade risc0-ethereum repo

Clone risc0-ethereum repo. You will notice that each significant Risc0 version bump has a matching branch with our changes, for instance release-1.2-soldeer or release-2.0-soldeer. We will do the same for this release.

1.1. Create new release branch

git checkout main
git checkout -b release-2.0-soldeer

1.2. Sync with Risc0 release

git remote add upstream [email protected]:risc0/risc0-ethereum
git fetch upstream
git checkout v2.0.0 # or whatever Risc0 has tagged the release as

1.3. Configure soldeer and remove submodules

See commit a5613d1c for an illustrative example.

1.3.1. Update .gitignore

Add the following line anywhere in .gitignore

# ...
contracts/dependencies/

1.3.2. Update Foundry config - contracts/foundry.toml

Point libs at ./dependencies and add [dependencies] header as the last header in the manifest

# ...
libs = ["./dependencies"]

# ...

[dependencies]

# See more config options https://book.getfoundry.sh/static/config.default.toml

1.3.3. Remove git submodules

$ git rm -f lib/forge-std lib/openzeppelin-contracts

1.4. Add soldeer dependencies

See commit ab6aaa37 for an illustrative example.

1.4.1. Add dependencies to manifest - contracts/foundry.toml

[dependencies]
forge-std = "1.9.4"
"@openzeppelin-contracts" = "5.1.0"

1.4.2. Tweak the remappings - contracts/remappings.txt

forge-std/=dependencies/forge-std-1.9.4/src
openzeppelin-contracts=dependencies/@openzeppelin-contracts-5.1.0/

1.4.3. Pull the dependencies from soldeer registry and commit the lock file

$ cd contracts
$ forge soldeer install
$ git add soldeer.lock
$ git commit

1.5. Refactor remappings in contracts

We need to tweak every contract that imports openzeppelin-contracts to import it as openzeppelin-contracts/... rather than openzeppelin/contracts/....

For example, take contracts/src/RiscZeroSetVerifier.sol

// ...
import {MerkleProof} from "openzeppelin-contracts/utils/cryptography/MerkleProof.sol";
// ...

See commit cf3d1381 for an illustrative example.

1.6. Pack contracts using soldeer

Packing contracts is equivalent to publishing the contracts with --dry-run flag on in soldeer lingo

$ forge soldeer push risc0-ethereum~2.0.0 contracts --dry-run

This command will generate contracts/contracts.zip that we will need in the next step.

1.7. Create GitHub release

Finally, create GitHub release by first tagging the branch and then uploading contracts/contracts.zip.

$ git tag v2.0.0-soldeer
$ git push origin tag v2.0.0-soldeer

1.8. Update Risc0 Ethereum contracts in the main repo

Now, let's circle back to the main repo (vlayer). We will need to propagate the new version of Solidity contracts in a few places.

1.8.1. Update main Cargo manifest - Cargo.toml

risc0-build-ethereum = { git = "https://github.com/vlayer-xyz/risc0-ethereum.git", rev = "cf3d1381f076f1094455a0fc6ebd5bd172424d09" }

Here the revision hash corresponds to the commit hash which we tagged in the risc0-ethereum repo.

1.8.2. Update foundry manifest - contracts/vlayer/foundry.toml

risc0-ethereum = { version = "2.0.0", url = "https://github.com/vlayer-xyz/risc0-ethereum/releases/download/v2.0.0-soldeer/contracts.zip" }

Note that the url should point to the zipped contracts we just created a GitHub release for in risc0-ethereum repo.

1.8.3. Update remappings - contracts/vlayer/remappings.txt and contracts/fixtures/remappings.txt

risc0-ethereum-2.0.0/=../vlayer/dependencies/risc0-ethereum-2.0.0/

1.8.4. Update vlayer-init config - bash/lib/e2e.sh and rust/cli/config.toml

[sol-dependencies.risc0-ethereum]
version = '2.0.0'
url = "https://github.com/vlayer-xyz/risc0-ethereum/releases/download/v2.0.0-soldeer/contracts.zip"
remappings = [["risc0-ethereum-2.0.0/", "dependencies/risc0-ethereum-2.0.0/"]]

1.8.5. Update imports in contracts

Change any risc0-ethereum import to the correct version.

1.8.6. Update Groth16 verifier selector - contracts/vlayer/test/helpers/Groth16VerifierSelector.sol and rust/services/call/seal/src/lib.rs

The new selector value can be extracted from risc0-ethereum/contracts/src/selector.rs and in particular, from the enum Selector. For example, v2.0 selector is tagged as Selector::Groth16V2_0 = 0x9f39696c.

Having noted this value down, we can now update the contracts and the seal:

library Groth16VerifierSelector {
    // value ensures that versions of risc0-ethereum and risc0-zkvm deps are compatible
    // must be kept in-sync with GROTH16_VERIFIER_SELECTOR value in rust/services/call/seal/src/lib.rs
    bytes4 public constant STABLE_VERIFIER_SELECTOR = bytes4(0x9f39696c);
}

#![allow(unused)]
fn main() {
    // stable, expected selector by solidity groth16 verifiers
    // must be kept in sync with value from `contracts/vlayer/test/helpers/Groth16VerifierSelector.sol`
    const GROTH16_VERIFIER_SELECTOR: VerifierSelector = VerifierSelector([0x9f, 0x39, 0x69, 0x6c]);
}

1.8.7. Fix Solidity integration tests - contracts/vlayer/test/integration/ProofVerifier.t.sol

Values that will require updating are:

FIXED_CALL_GUEST_ID
FIXED_GROTH16_SETTLE_BLOCK_HASH
FIXED_FAKE_SETTLE_BLOCK_HASH
sealBytes in fakeProofFixture()
sealBytes in groth16ProofFixture

Obtaining those new values requires running e2e-test.sh on simple example and copying the values from the generated proof.

Fake values

Run the following e2e test:

$ EXAMPLE=simple ./bash/e2e-test.sh

The values we are looking for can be matched in the output using the following blueprint:

Proof result: [
  {
    seal: {
      verifierSelector: "0xdeafbeef",
      seal: [ "sealBytes[0]",
        "0x0000000000000000000000000000000000000000000000000000000000000000", "0x0000000000000000000000000000000000000000000000000000000000000000",
        "0x0000000000000000000000000000000000000000000000000000000000000000", "0x0000000000000000000000000000000000000000000000000000000000000000",
        "0x0000000000000000000000000000000000000000000000000000000000000000", "0x0000000000000000000000000000000000000000000000000000000000000000",
        "0x0000000000000000000000000000000000000000000000000000000000000000"
      ],
      mode: 1,
    },
    callGuestId: "FIXED_CALL_GUEST_ID",
    length: 768,
    callAssumptions: {
      proverContractAddress: "0x9fe46736679d2d9a65f0992f2272de9f3c7fa6e0",
      functionSelector: "0xe3d670d7",
      settleChainId: "0x7a69",
      settleBlockNumber: "0x6",
      settleBlockHash: "FIXED_FAKE_SETTLE_BLOCK_HASH",
    },
  },
  "0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266", 10000000n
]

Groth16 values

Tweak bash/run_services/lib.sh so that startup_vlayer() always runs using remote Groth16 (Bonsai) prover:

function startup_vlayer() {
  local proof_arg="groth16";
  # ...
}

Next, execute e2e test with Bonsai credentials:

$ EXAMPLE=simple BONSAI_API_URL=https://api.bonsai.xyz BONSAI_API_KEY=... ./bash/e2e-test.sh

The values we are looking for can be matched as follows from the output:

Proof result: [
  {
    seal: {
      verifierSelector: "0x9f39696c",
      seal: [ "sealBytes[0]",
        "sealBytes[1]", "sealBytes[2]",
        "sealBytes[3]", "sealBytes[4]",
        "sealBytes[4]", "sealBytes[5]",
        "sealBytes[6]"
      ],
      mode: 0,
    },
    callGuestId: "FIXED_CALL_GUEST_ID",
    length: 768,
    callAssumptions: {
      proverContractAddress: "0x9fe46736679d2d9a65f0992f2272de9f3c7fa6e0",
      functionSelector: "0xe3d670d7",
      settleChainId: "0x7a69",
      settleBlockNumber: "0x6",
      settleBlockHash: "FIXED_GROTH16_SETTLE_BLOCK_HASH",
    },
  },
  "0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266", 10000000n
]

Generate new Guest ID using Docker

Make sure all previous steps have been performed successfully.

Generate new GuestID using Docker

$ UPDATE_GUEST_ELF_ID=1 RISC0_USE_DOCKER=1 cargo build

Go and get yourself a cup of coffee or something - this will take a while.

Update the CHANGELOG with the name of the change - rust/guest_wrapper/artifacts/chain_guest/CHANGELOG.md

# ...
* `<a_new_guest_id_value> - TODO`

replace TODO with an actual reason for an upgrade.

vlayer book

Upgrading Risc0

Upgrade r0vm and rust toolchain

Upgrade Rust cargo dependencies

(Optional) Upgrade Risc0 Ethereum contracts

Generate new Guest ID using Docker