## Motivation
`pallet-xcm` is the main user-facing interface for XCM functionality,
including assets manipulation functions like `teleportAssets()` and
`reserve_transfer_assets()` calls.
While `teleportAsset()` works both ways, `reserve_transfer_assets()`
works only for sending reserve-based assets to a remote destination and
beneficiary when the reserve is the _local chain_.
## Solution
This PR enhances `pallet_xcm::(limited_)reserve_withdraw_assets` to
support transfers when reserves are other chains.
This will allow complete, **bi-directional** reserve-based asset
transfers user stories using `pallet-xcm`.
Enables following scenarios:
- transferring assets with local reserve (was previously supported iff
asset used as fee also had local reserve - now it works in all cases),
- transferring assets with reserve on destination,
- transferring assets with reserve on remote/third-party chain (iff
assets and fees have same remote reserve),
- transferring assets with reserve different than the reserve of the
asset to be used as fees - meaning can be used to transfer random asset
with local/dest reserve while using DOT for fees on all involved chains,
even if DOT local/dest reserve doesn't match asset reserve,
- transferring assets with any type of local/dest reserve while using
fees which can be teleported between involved chains.
All of the above is done by pallet inner logic without the user having
to specify which scenario/reserves/teleports/etc. The correct scenario
and corresponding XCM programs are identified, and respectively, built
automatically based on runtime configuration of trusted teleporters and
trusted reserves.
#### Current limitations:
- while `fees` and "non-fee" `assets` CAN have different reserves (or
fees CAN be teleported), the remaining "non-fee" `assets` CANNOT, among
themselves, have different reserve locations (this is also implicitly
enforced by `MAX_ASSETS_FOR_TRANSFER=2`, but this can be safely
increased in the future).
- `fees` and "non-fee" `assets` CANNOT have **different remote**
reserves (this could also be supported in the future, but adds even more
complexity while possibly not being worth it - we'll see what the future
holds).
Fixes https://github.com/paritytech/polkadot-sdk/issues/1584
Fixes https://github.com/paritytech/polkadot-sdk/issues/2055
---------
Co-authored-by: Francisco Aguirre <franciscoaguirreperez@gmail.com>
Co-authored-by: Branislav Kontur <bkontur@gmail.com>
(imported from https://github.com/paritytech/cumulus/pull/2157)
## Changes
This MR refactores the XCMP, Parachains System and DMP pallets to use
the [MessageQueue](https://github.com/paritytech/substrate/pull/12485)
for delayed execution of incoming messages. The DMP pallet is entirely
replaced by the MQ and thereby removed. This allows for PoV-bounded
execution and resolves a number of issues that stem from the current
work-around.
All System Parachains adopt this change.
The most important changes are in `primitives/core/src/lib.rs`,
`parachains/common/src/process_xcm_message.rs`,
`pallets/parachain-system/src/lib.rs`, `pallets/xcmp-queue/src/lib.rs`
and the runtime configs.
### DMP Queue Pallet
The pallet got removed and its logic refactored into parachain-system.
Overweight message management can be done directly through the MQ
pallet.
Final undeployment migrations are provided by
`cumulus_pallet_dmp_queue::UndeployDmpQueue` and `DeleteDmpQueue` that
can be configured with an aux config trait like:
```rust
parameter_types! {
pub const DmpQueuePalletName: &'static str = \"DmpQueue\" < CHANGE ME;
pub const RelayOrigin: AggregateMessageOrigin = AggregateMessageOrigin::Parent;
}
impl cumulus_pallet_dmp_queue::MigrationConfig for Runtime {
type PalletName = DmpQueuePalletName;
type DmpHandler = frame_support::traits::EnqueueWithOrigin<MessageQueue, RelayOrigin>;
type DbWeight = <Runtime as frame_system::Config>::DbWeight;
}
// And adding them to your Migrations tuple:
pub type Migrations = (
...
cumulus_pallet_dmp_queue::UndeployDmpQueue<Runtime>,
cumulus_pallet_dmp_queue::DeleteDmpQueue<Runtime>,
);
```
### XCMP Queue pallet
Removed all dispatch queue functionality. Incoming XCMP messages are now
either: Immediately handled if they are Signals, enqueued into the MQ
pallet otherwise.
New config items for the XCMP queue pallet:
```rust
/// The actual queue implementation that retains the messages for later processing.
type XcmpQueue: EnqueueMessage<ParaId>;
/// How a XCM over HRMP from a sibling parachain should be processed.
type XcmpProcessor: ProcessMessage<Origin = ParaId>;
/// The maximal number of suspended XCMP channels at the same time.
#[pallet::constant]
type MaxInboundSuspended: Get<u32>;
```
How to configure those:
```rust
// Use the MessageQueue pallet to store messages for later processing. The `TransformOrigin` is needed since
// the MQ pallet itself operators on `AggregateMessageOrigin` but we want to enqueue `ParaId`s.
type XcmpQueue = TransformOrigin<MessageQueue, AggregateMessageOrigin, ParaId, ParaIdToSibling>;
// Process XCMP messages from siblings. This is type-safe to only accept `ParaId`s. They will be dispatched
// with origin `Junction::Sibling(…)`.
type XcmpProcessor = ProcessFromSibling<
ProcessXcmMessage<
AggregateMessageOrigin,
xcm_executor::XcmExecutor<xcm_config::XcmConfig>,
RuntimeCall,
>,
>;
// Not really important what to choose here. Just something larger than the maximal number of channels.
type MaxInboundSuspended = sp_core::ConstU32<1_000>;
```
The `InboundXcmpStatus` storage item was replaced by
`InboundXcmpSuspended` since it now only tracks inbound queue suspension
and no message indices anymore.
Now only sends the most recent channel `Signals`, as all prio ones are
out-dated anyway.
### Parachain System pallet
For `DMP` messages instead of forwarding them to the `DMP` pallet, it
now pushes them to the configured `DmpQueue`. The message processing
which was triggered in `set_validation_data` is now being done by the MQ
pallet `on_initialize`.
XCMP messages are still handed off to the `XcmpMessageHandler`
(XCMP-Queue pallet) - no change here.
New config items for the parachain system pallet:
```rust
/// Queues inbound downward messages for delayed processing.
///
/// Analogous to the `XcmpQueue` of the XCMP queue pallet.
type DmpQueue: EnqueueMessage<AggregateMessageOrigin>;
```
How to configure:
```rust
/// Use the MQ pallet to store DMP messages for delayed processing.
type DmpQueue = MessageQueue;
```
## Message Flow
The flow of messages on the parachain side. Messages come in from the
left via the `Validation Data` and finally end up at the `Xcm Executor`
on the right.
## Further changes
- Bumped the default suspension, drop and resume thresholds in
`QueueConfigData::default()`.
- `XcmpQueue::{suspend_xcm_execution, resume_xcm_execution}` errors when
they would be a noop.
- Properly validate the `QueueConfigData` before setting it.
- Marked weight files as auto-generated so they wont auto-expand in the
MR files view.
- Move the `hypothetical` asserts to `frame_support` under the name
`experimental_hypothetically`
Questions:
- [ ] What about the ugly `#[cfg(feature = \"runtime-benchmarks\")]` in
the runtimes? Not sure how to best fix. Just having them like this makes
tests fail that rely on the real message processor when the feature is
enabled.
- [ ] Need a good weight for `MessageQueueServiceWeight`. The scheduler
already takes 80% so I put it to 10% but that is quite low.
TODO:
- [x] Remove c&p code after
https://github.com/paritytech/polkadot/pull/6271
- [x] Use `HandleMessage` once it is public in Substrate
- [x] fix `runtime-benchmarks` feature
https://github.com/paritytech/polkadot/pull/6966
- [x] Benchmarks
- [x] Tests
- [ ] Migrate `InboundXcmpStatus` to `InboundXcmpSuspended`
- [x] Possibly cleanup Migrations (DMP+XCMP)
- [x] optional: create `TransformProcessMessageOrigin` in Substrate and
replace `ProcessFromSibling`
- [ ] Rerun weights on ref HW
---------
Signed-off-by: Oliver Tale-Yazdi <oliver.tale-yazdi@parity.io>
Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>
Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>
Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>
Co-authored-by: command-bot <>
This PR addresses several issues:
- simplify referencing `RelayTreasuryLocation` without needing
additional `RelayTreasury` struct
- fix for referencing `SystemParachains` from parachain with `parents:
1` instead of `parents: 0`
- removed hard-coded constants and fix tests for `asset-hub-rococo`
which was merged to master after
https://github.com/paritytech/polkadot-sdk/pull/1726
---------
Co-authored-by: command-bot <>
Combination of paritytech/polkadot#7005, its addon PR
paritytech/polkadot#7585 and its companion paritytech/cumulus#2433.
This PR introduces a new XcmFeesToAccount struct which implements the
`FeeManager` trait, and assigns this struct as the `FeeManager` in the
XCM config for all runtimes.
The struct simply deposits all fees handled by the XCM executor to a
specified account. In all runtimes, the specified account is configured
as the treasury account.
XCM __delivery__ fees are now being introduced (unless the root origin
is sending a message to a system parachain on behalf of the originating
chain).
# Note for reviewers
Most file changes are tests that had to be modified to account for the
new fees.
Main changes are in:
- cumulus/pallets/xcmp-queue/src/lib.rs <- To make it track the delivery
fees exponential factor
- polkadot/xcm/xcm-builder/src/fee_handling.rs <- Added. Has the
FeeManager implementation
- All runtime xcm_config files <- To add the FeeManager to the XCM
configuration
# Important note
After this change, instructions that create and send a new XCM (Query*,
Report*, ExportMessage, InitiateReserveWithdraw, InitiateTeleport,
DepositReserveAsset, TransferReserveAsset, LockAsset and RequestUnlock)
will require the corresponding origin account in the origin register to
pay for transport delivery fees, and the onward message will fail to be
sent if the origin account does not have the required amount. This
delivery fee is on top of what we already collect as tx fees in
pallet-xcm and XCM BuyExecution fees!
Wallet UIs that want to expose the new delivery fee can do so using the
formula:
```
delivery_fee_factor * (base_fee + encoded_msg_len * per_byte_fee)
```
where the delivery fee factor can be obtained from the corresponding
pallet based on which transport you are using (UMP, HRMP or bridges),
the base fee is a constant, the encoded message length from the message
itself and the per byte fee is the same as the configured per byte fee
for txs (i.e. `TransactionByteFee`).
---------
Co-authored-by: Branislav Kontur <bkontur@gmail.com>
Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>
Co-authored-by: Giles Cope <gilescope@gmail.com>
Co-authored-by: command-bot <>
Co-authored-by: Francisco Aguirre <franciscoaguirreperez@gmail.com>
Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>
Co-authored-by: Kian Paimani <5588131+kianenigma@users.noreply.github.com>
This commit adds Rococo Asset Hub dedicated runtime so we can test new
features here, before merging them in Kusama Asset Hub.
Also adds one such feature: asset transfer over bridge (Rococo AssetHub
<> Wococo AssetHub)
- clone `asset-hub-kusama-runtime` -> `asset-hub-rococo-runtime`
- make it use Rococo primitives, names, assets, constants, etc
- add asset-transfer-over-bridge support to Rococo AssetHub <> Wococo
AssetHub
Fixes#1128
---------
Co-authored-by: Branislav Kontur <bkontur@gmail.com>
Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>
Co-authored-by: Francisco Aguirre <franciscoaguirreperez@gmail.com>
* Rename `polkadot-parachain` to `polkadot-parachain-primitives`
While doing this it also fixes some last `rustdoc` issues and fixes
another Cargo warning related to `pallet-paged-list`.
* Fix compilation
* ".git/.scripts/commands/fmt/fmt.sh"
* Fix XCM docs
---------
Co-authored-by: command-bot <>
* companion for xcm alias origin
* update lockfile for {"polkadot", "substrate"}
* add benchmark function for runtimes
---------
Co-authored-by: parity-processbot <>
* Align BridgeHub runtimes with other SP runtimes
* Reused `teleports_for_native_asset_works` test to all bridge-hub runtime
* Fix import vs doc
* Removed unnecessery deps
* DealWithFees + ToAuthor->ToStakingPot for BH according to the other runtimes
* Update parachains/runtimes/bridge-hubs/bridge-hub-rococo/src/xcm_config.rs
Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>
* Update parachains/runtimes/bridge-hubs/bridge-hub-polkadot/src/xcm_config.rs
Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>
* Update parachains/runtimes/bridge-hubs/bridge-hub-kusama/src/xcm_config.rs
Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>
* Align all desc
* Extract runtime_para_id for test
* Fix test
---------
Co-authored-by: parity-processbot <>
Co-authored-by: joe petrowski <25483142+joepetrowski@users.noreply.github.com>
Adrian Catangiu