Dear Polkadot Community,
We are pleased to present our proposal for retroactive funding for the Polkadot Virtual Machine (PVM) Debugger, a tool designed to streamline the development and validation of PVM implementations. This open-source debugger offers key functionalities such as breakpoints, memory inspection, and parallel execution across multiple PVM clients, enabling developers to identify discrepancies and ensure alignment with formal specifications.
The PVM Debugger was created to address the lack of specialized tools for debugging and validating PVM programs. By providing detailed insights into program execution and memory states, it aims to enhance development efficiency and improve the robustness of PVM implementations across the Polkadot ecosystem.
Full proposal text: https://docs.google.com/document/d/1plq5C0kdMMuHscGNqnhvw0TebqXLZXQsIfqcbVLf-6M
General Project Information
Project Category / Type: Software development
Proponent: FluffyLabs.dev
USDT address: 15fGrDWmFoaApnZXEw1Zg45zuCqpkbMS9YPzczeU9dHseUUu
Requested allocation: 16.000 USD
Income taxable: 19% tax on “virtual currencies” tax in Poland: https://www.podatki.gov.pl/en/your-e-pit/pit-38-for-2022/
Discussion date: 24th November 2024
Onchain publish date: scheduled for 5th December 2024
Previous treasury proposals: none
Context
The JAM (Join-Accumulate Machine) prize is a Polkadot initiative that encourages teams to develop diverse implementations of the new iteration of Polkadot network proposed by Gavin Wood. As part of the implementation of the JAM protocol, teams need to implement the Polkadot Virtual Machine (PVM) which is responsible for execution of the state transition of underlying services. This implementation diversity is essential for ensuring the Polkadot network remains flexible, secure, and resilient. However, building these various PVM implementations introduces significant technical challenges, particularly around debugging and analyzing the behavior of PVM programs across different client implementations.
Our team is one of the participants in the JAM prize, focusing on creating a robust PVM interpreter. During our work, we realized the need for a specialized tool to streamline debugging and validation processes. Standard debugging tools did not provide the level of insight required to efficiently inspect program execution, memory usage, and register interactions within the PVM.
To address this, we developed the PVM Disassembler & Debugger (https://pvm.fluffylabs.dev) specifically tailored for the JAM ecosystem. The tool includes a machine code and assembly view, allowing developers to inspect the PVM programs at a low level. After plugging in one of many possible PVM interpreter implementations, it also offers key debugging features such as step-over functionality, breakpoints, and memory inspection, giving developers a detailed view of program behavior during execution.A significant potential benefit of the debugger is its ability to validate programs simultaneously across multiple PVM implementations, helping teams participating in the JAM prize identify discrepancies and improve client interoperability.
While the tool was initially created for our own development purposes, we recognized its value for the broader Polkadot community and have decided to open-source it. This will allow other teams to use the debugger for cross-client validation and debugging, accelerating their development process and ensuring the robustness of their PVM implementations.
Problem
The development of diverse Polkadot Virtual Machine (PVM) implementations, as encouraged by the JAM prize, introduces significant technical challenges. Developers might struggle with debugging and validating PVM programs across different implementations, lacking tools to gain deep insights into program execution, memory states, and discrepancies between clients. This slows down development and increases the risk of bugs going undetected.
Additionally, we believe the PVM Disassembler & Debugger will serve a greater educational purpose of introducing a new wave of developers that are going to build Services on top of JAM. With references to Gray Paper definitions of instructions we strive to make it easier to understand in depth the complexity of PVM’s formal specification.
While our current main focus is creating a tool that would serve JAM implementers, with a proposal Solidity smart contracts running on top of PolkaVM on Asset Hub: https://forum.polkadot.network/t/contracts-update-solidity-on-polkavm/6949, the PVM Disassembler & Debugger might prove itself useful much wider.
Proposal
We propose retroactive funding of the PVM Disassembler & Debugger aimed at supporting the implementers of Polkadot Virtual Machine (PVM) interpreters as part of the JAM prize. The tool addresses the complexities and technical challenges developers face when debugging and validating PVM programs. Our goal is to provide a robust solution that helps developers better understand program execution, identify discrepancies between multiple PVM implementations, and align with the formal specifications in the Gray Paper.
By creating this open-source debugger, we aimed to not only solve immediate development issues but also contribute to the long-term robustness of the Polkadot/JAM ecosystem by promoting client diversity, enhancing the overall quality of PVM implementations and helping the builders of programs running on top of the PVM.
Please note that the JAM prize or other funding mechanisms do not cover tooling for JAM. The JAM prize focuses on client implementations but does not cover the development of ecosystem tools such as debuggers, which benefit all participants. This is why we are submitting this proposal directly to the treasury and the Polkadot ecosystem.
Available solutions
While RISC-V debuggers exist, there is no dedicated debugger for PVM currently available. Even if one existed, it would probably not support running a program in parallel across multiple PVM implementations, which is crucial for identifying discrepancies in client behavior—something that traditional debugging tools cannot achieve in a standard debugging setup. This project aims to fill that gap with a PVM-specific debugger tailored to the unique requirements of the JAM ecosystem.
Scope of work
The PVM Debugger (https://pvm.fluffylabs.dev) initial version 1.0 has been completed, providing a basic range of functionalities to support PVM client implementations in the Polkadot ecosystem. Below is an outline of the key deliverables and functionalities. The deliverable is under Mozilla Public License (MPL-2.0) license.
Deliverables
Key Functionalities
Ensuring Adoption and Onboarding Support for the PVM Debugger
For information on Adoption and Onboarding, please refer to “Detailed proposal: Scope of work > Ensuring Adoption and Onboarding Support for the PVM Debugger”
Timeline
For timeline details, please refer to “Detailed proposal: Timeline”
Budget
Total Budget
Developer Hours: 140 hours × $100/hour = $14,000
Product Management Hours: 20 hours × $100/hour = $2,000
Total: $16,000 (16,000 USDT)
This budget represents the full scope of work required to develop and deliver the open-source PVM Debugger, which is now available for the Polkadot and JAM communities.
For full budget breakdown, please refer to “Detailed proposal: Budget”
Payment condition
For payment conditions details, please refer to “Detailed proposal: Payment Conditions”
Key deliverables
1. Software
typeberry’s PVM implementation (TypeScript)
PolkaVM reference implementation (Rust)
Gosamer’s team PVM implementation (Go)
2. Code Repository
GitHub Repository: The complete source code for the debugger has been made available in a public repository (https://github.com/FluffyLabs/pvm-debugger), providing full transparency and allowing further community development.
Objectives / Success criteria
The success of the PVM Debugger project will be measured based on several key criteria focused on its adoption and utility within the Polkadot and JAM communities. These criteria will help determine if the project has met its objectives and if the final deliverable is satisfactory:
1. Adoption by Other JAM Teams
2. Community Feedback
These success criteria will confirm that the PVM Debugger is an effective tool that serves its intended purpose of improving PVM implementation and debugging within the Polkadot ecosystem.
Known constraints
As we continue to expand the PVM Debugger by integrating additional PVM implementations, there are some known constraints that may affect future efforts:
These constraints will be considered when expanding the debugger to support additional PVM implementations.
Reporting
Since the PVM Debugger project is already completed and this proposal seeks retroactive funding, there is no need for ongoing reporting related to the development process. However, the history of commits and progress can be fully tracked and reviewed on GitHub, providing full transparency on the project's timeline and milestones.
Should any future updates or enhancements be made, relevant information will be shared through appropriate channels, such as GitHub or Polkadot community forums.
Communication strategy
Contact Information:
Team Member: Piotr Zwolinski
Email: [email protected]
Element: @tomusdrw:matrix.org
Team
The PVM Debugger was built by the FluffyLabs team, a group involved in the development of decentralized tools for the Polkadot ecosystem:
For full team members details, please refer to “Detailed proposal: Team”
Why Polkadot
The Polkadot ecosystem is a cutting-edge of blockchain innovation that builds trustless, privacy-preserving solutions, which are the foundations of Web3.0. JAM, as an important next step for Polkadot development, stands as a crucial initiative to make that vision happen. Our values are fully aligned and we are seeing an opportunity to build the development tooling for JAM as early as possible to make sure we are ready to get wider developer adoption of the protocol.
Comments, Qs&As
How does the PVM Debugger benefit teams beyond the JAM prize? Since the PVM is going to be an execution bedrock of future JAM services, we hope that the PVM Debugger (and its future iterations) will help not only the JAM implementers, but also the developers building services on top of JAM. Moreover, given the proposal to have Solidity Smart Contracts on PVM running on Asset Hub (https://forum.polkadot.network/t/contracts-update-solidity-on-polkavm/6949) we are considering to support more specialized debugging primitives for such contracts (like supporting debug symbols or the required host calls - cross contract calls, storage, etc).
Why are you requesting retroactive funding instead of building this under the JAM prize? The JAM prize focuses on client implementations but does not cover the development of ecosystem tools like e.g. debuggers, which benefit all participants. We developed the PVM Debugger to solve problems that arose during our own implementation and are now making it available to the entire community. Retroactive funding allows us to recover the costs of building this tool and ensures that it remains freely available and open-source.
Will there be further development of the PVM Debugger? While this proposal is specifically for retroactive funding, we are going to continue developing the PVM Debugger to add more features and integrations in the future. However, these future developments are independent from the current funding request.
How will you ensure that the debugger remains relevant as Polkadot evolves? The PVM Debugger is built to be flexible, allowing integration with new PVM implementations as they emerge. By keeping the tool open-source, we also invite contributions from the wider developer community to help ensure it remains relevant and aligned with Polkadot’s ongoing development.
Your feedback
We welcome feedback and suggestions from the Polkadot community to ensure the PVM Debugger meets the needs of developers and contributes effectively to the ecosystem. Your insights will help us refine the tool, prioritize future features, and maximize its impact. Please share your thoughts on Polkassembly or reach out to us directly through the provided channels. We look forward to collaborating with you to strengthen the Polkadot ecosystem together!
Project Overview: The PVM Debugger is an open-source tool designed to streamline the development and validation of Polkadot Virtual Machine (PVM) implementations. It offers features like breakpoints, memory inspection, and parallel execution across multiple PVM clients.
Purpose: The tool addresses the lack of specialized debugging tools for PVM programs, aiming to enhance development efficiency and improve the robustness of PVM implementations in the Polkadot ecosystem.
Proposal Details: The proposal seeks retroactive funding for the PVM Debugger, which was initially developed for the JAM prize but is now open-sourced for broader community use. The requested allocation is 16,000 USD.
Key Functionalities: The debugger includes features such as step-over, breakpoints, memory and register inspection, machine code/assembly view, and parallel execution across multiple PVM implementations.
Adoption and Support: The team plans to ensure adoption by other JAM teams and gather community feedback to refine the tool. They also aim to continue developing the debugger for future PVM implementations.
Budget: The total budget breakdown includes 140 hours of developer work and 20 hours of product management, totaling 16,000 USD.
Team: The PVM Debugger was developed by FluffyLabs, a team involved in building decentralized tools for the Polkadot ecosystem.
Community Engagement: The team welcomes feedback and suggestions from the Polkadot community to improve the tool and ensure it meets the needs of developers.