A mode for sandbox where it supports deterministic execution

[pepyakin]

Right now, the sandboxing feature doesn't enforce any deterministic execution. It's deferred to the runtime. However, in the context of #8153 and PVF execution, we would want to make sandboxed execution deterministic.

[bkchr]

Don't we always want deterministic execution? Or why do we only need this in the the PVF?

[pepyakin]

All the reasonable chains would want to have deterministic execution in sandboxes, but it is up to the Runtime to ensure that. We don't do that by default because the runtime can know better how to ensure that: e.g. if the Runtime uses sandbox to execute parts of itself, it can be pretty sure that no additional measures are needed because the Runtime is assumed to be deterministic. The Runtime can also generate code which is deterministic by construction.

It's actually similar to the determinism relationships between PVF and Substrate execution. Substrate Runtime can be not deterministic but it's up to the Runtime itself. If it exploits non determinism then only the chain itself will suffer. However, non-determinism in Polkadot is more serious since a malicious PVF that exploits non-determinism would consume validators and can trigger disputes, slashing and delay inclusion, etc.

So we should make sandbox execution deterministic in case it runs in the context of PVF execution

[stale]

Hey, is anyone still working on this? Due to the inactivity this issue has been automatically marked as stale. It will be closed if no further activity occurs. Thank you for your contributions.