Enable async backing on asset-hub-rococo (#2826)

The goal is to move all system chains on Rococo (+ other testnets?) to
use async backing.

Starting with `asset-hub-rococo` to get feedback, before I do the rest.

## Related

Example: https://github.com/paritytech/polkadot-sdk/pull/1619/
Guide:
https://github.com/w3f/polkadot-wiki/blob/master/docs/maintain/maintain-guides-async-backing.md

---------

Co-authored-by: Branislav Kontur <bkontur@gmail.com>
Co-authored-by: Dónal Murray <donal.murray@parity.io>

cumulus/parachains/runtimes/assets/asset-hub-rococo/Cargo.toml

@@ -77,6 +77,7 @@ cumulus-pallet-parachain-system = { path = "../../../../pallets/parachain-system
 cumulus-pallet-session-benchmarking = { path = "../../../../pallets/session-benchmarking", default-features = false }
 cumulus-pallet-xcm = { path = "../../../../pallets/xcm", default-features = false }
 cumulus-pallet-xcmp-queue = { path = "../../../../pallets/xcmp-queue", default-features = false, features = ["bridging"] }
+cumulus-primitives-aura = { path = "../../../../primitives/aura", default-features = false }
 cumulus-primitives-core = { path = "../../../../primitives/core", default-features = false }
 cumulus-primitives-utility = { path = "../../../../primitives/utility", default-features = false }
 pallet-collator-selection = { path = "../../../../pallets/collator-selection", default-features = false }
@@ -188,6 +189,7 @@ std = [
 	"cumulus-pallet-session-benchmarking/std",
 	"cumulus-pallet-xcm/std",
 	"cumulus-pallet-xcmp-queue/std",
+	"cumulus-primitives-aura/std",
 	"cumulus-primitives-core/std",
 	"cumulus-primitives-utility/std",
 	"frame-benchmarking?/std",

cumulus/parachains/runtimes/assets/asset-hub-rococo/src/lib.rs

@@ -33,7 +33,7 @@ use assets_common::{
 	matching::{FromNetwork, FromSiblingParachain},
 	AssetIdForTrustBackedAssetsConvert,
 };
-use cumulus_pallet_parachain_system::RelayNumberStrictlyIncreases;
+use cumulus_pallet_parachain_system::RelayNumberMonotonicallyIncreases;
 use cumulus_primitives_core::AggregateMessageOrigin;
 use parachains_common::rococo::snowbridge::EthereumNetwork;
 use sp_api::impl_runtime_apis;
@@ -62,7 +62,7 @@ use frame_support::{
 		ConstU128, ConstU32, ConstU64, ConstU8, EitherOfDiverse, Equals, InstanceFilter,
 		TransformOrigin,
 	},
-	weights::{ConstantMultiplier, Weight},
+	weights::{constants::WEIGHT_REF_TIME_PER_SECOND, ConstantMultiplier, Weight},
 	BoundedVec, PalletId,
 };
 use frame_system::{
@@ -71,14 +71,13 @@ use frame_system::{
 };
 use pallet_asset_conversion_tx_payment::AssetConversionAdapter;
 use pallet_nfts::PalletFeatures;
-pub use parachains_common as common;
 use parachains_common::{
 	impls::DealWithFees,
 	message_queue::{NarrowOriginToSibling, ParaIdToSibling},
 	rococo::{consensus::*, currency::*, fee::WeightToFee},
 	AccountId, AssetIdForTrustBackedAssets, AuraId, Balance, BlockNumber, CollectionId, Hash,
 	Header, ItemId, Nonce, Signature, AVERAGE_ON_INITIALIZE_RATIO, DAYS, HOURS,
-	MAXIMUM_BLOCK_WEIGHT, NORMAL_DISPATCH_RATIO, SLOT_DURATION,
+	NORMAL_DISPATCH_RATIO,
 };
 use sp_runtime::{Perbill, RuntimeDebug};
 use xcm_config::{
@@ -141,6 +140,28 @@ pub fn native_version() -> NativeVersion {
 	NativeVersion { runtime_version: VERSION, can_author_with: Default::default() }
 }
 
+/// We allow for 2 seconds of compute with a 6 second average block.
+const MAXIMUM_BLOCK_WEIGHT: Weight = Weight::from_parts(
+	WEIGHT_REF_TIME_PER_SECOND.saturating_mul(2),
+	cumulus_primitives_core::relay_chain::MAX_POV_SIZE as u64,
+);
+
+/// Maximum number of blocks simultaneously accepted by the Runtime, not yet included
+/// into the relay chain.
+const UNINCLUDED_SEGMENT_CAPACITY: u32 = 3;
+/// How many parachain blocks are processed by the relay chain per parent. Limits the
+/// number of blocks authored per slot.
+const BLOCK_PROCESSING_VELOCITY: u32 = 1;
+
+/// This determines the average expected block time that we are targeting.
+/// Blocks will be produced at a minimum duration defined by `SLOT_DURATION`.
+/// `SLOT_DURATION` is picked up by `pallet_timestamp` which is in turn picked
+/// up by `pallet_aura` to implement `fn slot_duration()`.
+///
+/// Change this to adjust the block time.
+pub const MILLISECS_PER_BLOCK: u64 = 6000;
+pub const SLOT_DURATION: u64 = MILLISECS_PER_BLOCK;
+
 parameter_types! {
 	pub const Version: RuntimeVersion = VERSION;
 	pub RuntimeBlockLength: BlockLength =
@@ -189,6 +210,9 @@ impl pallet_timestamp::Config for Runtime {
 	/// A timestamp: milliseconds since the unix epoch.
 	type Moment = u64;
 	type OnTimestampSet = Aura;
+	#[cfg(feature = "experimental")]
+	type MinimumPeriod = ConstU64<0>;
+	#[cfg(not(feature = "experimental"))]
 	type MinimumPeriod = ConstU64<{ SLOT_DURATION / 2 }>;
 	type WeightInfo = weights::pallet_timestamp::WeightInfo<Runtime>;
 }
@@ -630,15 +654,17 @@ impl cumulus_pallet_parachain_system::Config for Runtime {
 	type OutboundXcmpMessageSource = XcmpQueue;
 	type XcmpMessageHandler = XcmpQueue;
 	type ReservedXcmpWeight = ReservedXcmpWeight;
-	type CheckAssociatedRelayNumber = RelayNumberStrictlyIncreases;
-	type ConsensusHook = cumulus_pallet_aura_ext::FixedVelocityConsensusHook<
-		Runtime,
-		RELAY_CHAIN_SLOT_DURATION_MILLIS,
-		BLOCK_PROCESSING_VELOCITY,
-		UNINCLUDED_SEGMENT_CAPACITY,
-	>;
+	type CheckAssociatedRelayNumber = RelayNumberMonotonicallyIncreases;
+	type ConsensusHook = ConsensusHook;
 }
 
+type ConsensusHook = cumulus_pallet_aura_ext::FixedVelocityConsensusHook<
+	Runtime,
+	RELAY_CHAIN_SLOT_DURATION_MILLIS,
+	BLOCK_PROCESSING_VELOCITY,
+	UNINCLUDED_SEGMENT_CAPACITY,
+>;
+
 parameter_types! {
 	pub MessageQueueServiceWeight: Weight = Perbill::from_percent(35) * RuntimeBlockWeights::get().max_block;
 }
@@ -722,9 +748,9 @@ impl pallet_aura::Config for Runtime {
 	type AuthorityId = AuraId;
 	type DisabledValidators = ();
 	type MaxAuthorities = ConstU32<100_000>;
-	type AllowMultipleBlocksPerSlot = ConstBool<false>;
+	type AllowMultipleBlocksPerSlot = ConstBool<true>;
 	#[cfg(feature = "experimental")]
-	type SlotDuration = pallet_aura::MinimumPeriodTimesTwo<Self>;
+	type SlotDuration = ConstU64<SLOT_DURATION>;
 }
 
 parameter_types! {
@@ -1067,7 +1093,7 @@ mod benches {
 impl_runtime_apis! {
 	impl sp_consensus_aura::AuraApi<Block, AuraId> for Runtime {
 		fn slot_duration() -> sp_consensus_aura::SlotDuration {
-			sp_consensus_aura::SlotDuration::from_millis(Aura::slot_duration())
+			sp_consensus_aura::SlotDuration::from_millis(SLOT_DURATION)
 		}
 
 		fn authorities() -> Vec<AuraId> {
@@ -1075,6 +1101,15 @@ impl_runtime_apis! {
 		}
 	}
 
+	impl cumulus_primitives_aura::AuraUnincludedSegmentApi<Block> for Runtime {
+		fn can_build_upon(
+			included_hash: <Block as BlockT>::Hash,
+			slot: cumulus_primitives_aura::Slot,
+		) -> bool {
+			ConsensusHook::can_build_upon(included_hash, slot)
+		}
+	}
+
 	impl sp_api::Core<Block> for Runtime {
 		fn version() -> RuntimeVersion {
 			VERSION

cumulus/parachains/runtimes/assets/asset-hub-rococo/tests/tests.rs

@@ -28,10 +28,11 @@ use asset_hub_rococo_runtime::{
 	AllPalletsWithoutSystem, AssetConversion, AssetDeposit, Assets, Balances, CollatorSelection,
 	ExistentialDeposit, ForeignAssets, ForeignAssetsInstance, MetadataDepositBase,
 	MetadataDepositPerByte, ParachainSystem, Runtime, RuntimeCall, RuntimeEvent, SessionKeys,
-	ToWestendXcmRouterInstance, TrustBackedAssetsInstance, XcmpQueue,
+	ToWestendXcmRouterInstance, TrustBackedAssetsInstance, XcmpQueue, SLOT_DURATION,
 };
 use asset_test_utils::{
-	test_cases_over_bridge::TestBridgingConfig, CollatorSessionKey, CollatorSessionKeys, ExtBuilder,
+	test_cases_over_bridge::TestBridgingConfig, CollatorSessionKey, CollatorSessionKeys,
+	ExtBuilder, SlotDurations,
 };
 use codec::{Decode, Encode};
 use cumulus_primitives_utility::ChargeWeightInFungibles;
@@ -46,9 +47,10 @@ use frame_support::{
 	weights::{Weight, WeightToFee as WeightToFeeT},
 };
 use parachains_common::{
-	rococo::{currency::UNITS, fee::WeightToFee},
+	rococo::{consensus::RELAY_CHAIN_SLOT_DURATION_MILLIS, currency::UNITS, fee::WeightToFee},
 	AccountId, AssetIdForTrustBackedAssets, AuraId, Balance,
 };
+use sp_consensus_aura::SlotDuration;
 use sp_runtime::traits::MaybeEquivalence;
 use std::convert::Into;
 use xcm::latest::prelude::{Assets as XcmAssets, *};
@@ -78,6 +80,13 @@ fn collator_session_keys() -> CollatorSessionKeys<Runtime> {
 	CollatorSessionKeys::default().add(collator_session_key(ALICE))
 }
 
+fn slot_durations() -> SlotDurations {
+	SlotDurations {
+		relay: SlotDuration::from_millis(RELAY_CHAIN_SLOT_DURATION_MILLIS.into()),
+		para: SlotDuration::from_millis(SLOT_DURATION),
+	}
+}
+
 #[test]
 fn test_buy_and_refund_weight_in_native() {
 	ExtBuilder::<Runtime>::default()
@@ -892,6 +901,7 @@ asset_test_utils::include_teleports_for_native_asset_works!(
 	WeightToFee,
 	ParachainSystem,
 	collator_session_keys(),
+	slot_durations(),
 	ExistentialDeposit::get(),
 	Box::new(|runtime_event_encoded: Vec<u8>| {
 		match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
@@ -912,6 +922,7 @@ asset_test_utils::include_teleports_for_foreign_assets_works!(
 	ForeignCreatorsSovereignAccountOf,
 	ForeignAssetsInstance,
 	collator_session_keys(),
+	slot_durations(),
 	ExistentialDeposit::get(),
 	Box::new(|runtime_event_encoded: Vec<u8>| {
 		match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
@@ -1023,6 +1034,7 @@ fn limited_reserve_transfer_assets_for_native_asset_over_bridge_works(
 		LocationToAccountId,
 	>(
 		collator_session_keys(),
+		slot_durations(),
 		ExistentialDeposit::get(),
 		AccountId::from(ALICE),
 		Box::new(|runtime_event_encoded: Vec<u8>| {
@@ -1194,6 +1206,7 @@ mod asset_hub_rococo_tests {
 			LocationToAccountId,
 		>(
 			collator_session_keys(),
+			slot_durations(),
 			ExistentialDeposit::get(),
 			AccountId::from(ALICE),
 			Box::new(|runtime_event_encoded: Vec<u8>| {

cumulus/parachains/runtimes/assets/asset-hub-westend/src/lib.rs

@@ -55,7 +55,6 @@ use frame_system::{
 use pallet_asset_conversion_tx_payment::AssetConversionAdapter;
 use pallet_nfts::{DestroyWitness, PalletFeatures};
 use pallet_xcm::EnsureXcm;
-pub use parachains_common as common;
 use parachains_common::{
 	impls::DealWithFees,
 	message_queue::*,

cumulus/parachains/runtimes/assets/asset-hub-westend/tests/tests.rs

@@ -32,7 +32,8 @@ use asset_hub_westend_runtime::{
 };
 pub use asset_hub_westend_runtime::{AssetConversion, AssetDeposit, CollatorSelection, System};
 use asset_test_utils::{
-	test_cases_over_bridge::TestBridgingConfig, CollatorSessionKey, CollatorSessionKeys, ExtBuilder,
+	test_cases_over_bridge::TestBridgingConfig, CollatorSessionKey, CollatorSessionKeys,
+	ExtBuilder, SlotDurations,
 };
 use codec::{Decode, Encode};
 use cumulus_primitives_utility::ChargeWeightInFungibles;
@@ -47,9 +48,10 @@ use frame_support::{
 	weights::{Weight, WeightToFee as WeightToFeeT},
 };
 use parachains_common::{
-	westend::{currency::UNITS, fee::WeightToFee},
-	AccountId, AssetIdForTrustBackedAssets, AuraId, Balance,
+	westend::{consensus::RELAY_CHAIN_SLOT_DURATION_MILLIS, currency::UNITS, fee::WeightToFee},
+	AccountId, AssetIdForTrustBackedAssets, AuraId, Balance, SLOT_DURATION,
 };
+use sp_consensus_aura::SlotDuration;
 use sp_runtime::traits::MaybeEquivalence;
 use std::convert::Into;
 use xcm::latest::prelude::{Assets as XcmAssets, *};
@@ -79,6 +81,13 @@ fn collator_session_keys() -> CollatorSessionKeys<Runtime> {
 	CollatorSessionKeys::default().add(collator_session_key(ALICE))
 }
 
+fn slot_durations() -> SlotDurations {
+	SlotDurations {
+		relay: SlotDuration::from_millis(RELAY_CHAIN_SLOT_DURATION_MILLIS.into()),
+		para: SlotDuration::from_millis(SLOT_DURATION),
+	}
+}
+
 #[test]
 fn test_buy_and_refund_weight_in_native() {
 	ExtBuilder::<Runtime>::default()
@@ -895,6 +904,7 @@ asset_test_utils::include_teleports_for_native_asset_works!(
 	WeightToFee,
 	ParachainSystem,
 	collator_session_keys(),
+	slot_durations(),
 	ExistentialDeposit::get(),
 	Box::new(|runtime_event_encoded: Vec<u8>| {
 		match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
@@ -915,6 +925,7 @@ asset_test_utils::include_teleports_for_foreign_assets_works!(
 	ForeignCreatorsSovereignAccountOf,
 	ForeignAssetsInstance,
 	collator_session_keys(),
+	slot_durations(),
 	ExistentialDeposit::get(),
 	Box::new(|runtime_event_encoded: Vec<u8>| {
 		match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
@@ -1041,6 +1052,7 @@ fn limited_reserve_transfer_assets_for_native_asset_to_asset_hub_rococo_works()
 		LocationToAccountId,
 	>(
 		collator_session_keys(),
+		slot_durations(),
 		ExistentialDeposit::get(),
 		AccountId::from(ALICE),
 		Box::new(|runtime_event_encoded: Vec<u8>| {
@@ -1208,6 +1220,7 @@ fn reserve_transfer_native_asset_to_non_teleport_para_works() {
 		LocationToAccountId,
 	>(
 		collator_session_keys(),
+		slot_durations(),
 		ExistentialDeposit::get(),
 		AccountId::from(ALICE),
 		Box::new(|runtime_event_encoded: Vec<u8>| {

cumulus/parachains/runtimes/assets/test-utils/src/test_cases.rs

@@ -31,7 +31,7 @@ use frame_system::pallet_prelude::BlockNumberFor;
 use parachains_common::{AccountId, Balance};
 use parachains_runtimes_test_utils::{
 	assert_metadata, assert_total, mock_open_hrmp_channel, AccountIdOf, BalanceOf,
-	CollatorSessionKeys, ExtBuilder, ValidatorIdOf, XcmReceivedFrom,
+	CollatorSessionKeys, ExtBuilder, SlotDurations, ValidatorIdOf, XcmReceivedFrom,
 };
 use sp_runtime::{
 	traits::{MaybeEquivalence, StaticLookup, Zero},
@@ -57,6 +57,7 @@ pub fn teleports_for_native_asset_works<
 	HrmpChannelOpener,
 >(
 	collator_session_keys: CollatorSessionKeys<Runtime>,
+	slot_durations: SlotDurations,
 	existential_deposit: BalanceOf<Runtime>,
 	target_account: AccountIdOf<Runtime>,
 	unwrap_pallet_xcm_event: Box<dyn Fn(Vec<u8>) -> Option<pallet_xcm::Event<Runtime>>>,
@@ -205,6 +206,7 @@ pub fn teleports_for_native_asset_works<
 					None,
 					included_head.clone(),
 					&alice,
+					&slot_durations,
 				));
 
 				// check balances
@@ -257,6 +259,7 @@ pub fn teleports_for_native_asset_works<
 						Some((runtime_para_id, other_para_id)),
 						included_head,
 						&alice,
+						&slot_durations,
 					),
 					Err(DispatchError::Module(sp_runtime::ModuleError {
 						index: 31,
@@ -288,6 +291,7 @@ macro_rules! include_teleports_for_native_asset_works(
 		$weight_to_fee:path,
 		$hrmp_channel_opener:path,
 		$collator_session_key:expr,
+		$slot_durations:expr,
 		$existential_deposit:expr,
 		$unwrap_pallet_xcm_event:expr,
 		$runtime_para_id:expr
@@ -306,6 +310,7 @@ macro_rules! include_teleports_for_native_asset_works(
 				$hrmp_channel_opener
 			>(
 				$collator_session_key,
+				$slot_durations,
 				$existential_deposit,
 				target_account,
 				$unwrap_pallet_xcm_event,
@@ -328,6 +333,7 @@ pub fn teleports_for_foreign_assets_works<
 	ForeignAssetsPalletInstance,
 >(
 	collator_session_keys: CollatorSessionKeys<Runtime>,
+	slot_durations: SlotDurations,
 	target_account: AccountIdOf<Runtime>,
 	existential_deposit: BalanceOf<Runtime>,
 	asset_owner: AccountIdOf<Runtime>,
@@ -592,6 +598,7 @@ pub fn teleports_for_foreign_assets_works<
 					Some((runtime_para_id, foreign_para_id)),
 					included_head,
 					&alice,
+					&slot_durations,
 				));
 
 				// check balances
@@ -644,6 +651,7 @@ macro_rules! include_teleports_for_foreign_assets_works(
 		$sovereign_account_of:path,
 		$assets_pallet_instance:path,
 		$collator_session_key:expr,
+		$slot_durations:expr,
 		$existential_deposit:expr,
 		$unwrap_pallet_xcm_event:expr,
 		$unwrap_xcmp_queue_event:expr
@@ -666,6 +674,7 @@ macro_rules! include_teleports_for_foreign_assets_works(
 				$assets_pallet_instance
 			>(
 				$collator_session_key,
+				$slot_durations,
 				target_account,
 				$existential_deposit,
 				asset_owner,
@@ -1397,6 +1406,7 @@ pub fn reserve_transfer_native_asset_to_non_teleport_para_works<
 	LocationToAccountId,
 >(
 	collator_session_keys: CollatorSessionKeys<Runtime>,
+	slot_durations: SlotDurations,
 	existential_deposit: BalanceOf<Runtime>,
 	alice_account: AccountIdOf<Runtime>,
 	unwrap_pallet_xcm_event: Box<dyn Fn(Vec<u8>) -> Option<pallet_xcm::Event<Runtime>>>,
@@ -1470,6 +1480,7 @@ pub fn reserve_transfer_native_asset_to_non_teleport_para_works<
 				other_para_id.into(),
 				included_head,
 				&alice,
+				&slot_durations,
 			);
 
 			// we calculate exact delivery fees _after_ sending the message by weighing the sent

cumulus/parachains/runtimes/assets/test-utils/src/test_cases_over_bridge.rs

@@ -27,7 +27,7 @@ use frame_system::pallet_prelude::BlockNumberFor;
 use parachains_common::{AccountId, Balance};
 use parachains_runtimes_test_utils::{
 	mock_open_hrmp_channel, AccountIdOf, BalanceOf, CollatorSessionKeys, ExtBuilder, RuntimeHelper,
-	ValidatorIdOf, XcmReceivedFrom,
+	SlotDurations, ValidatorIdOf, XcmReceivedFrom,
 };
 use sp_runtime::{traits::StaticLookup, Saturating};
 use sp_std::ops::Mul;
@@ -52,6 +52,7 @@ pub fn limited_reserve_transfer_assets_for_native_asset_works<
 	LocationToAccountId,
 >(
 	collator_session_keys: CollatorSessionKeys<Runtime>,
+	slot_durations: SlotDurations,
 	existential_deposit: BalanceOf<Runtime>,
 	alice_account: AccountIdOf<Runtime>,
 	unwrap_pallet_xcm_event: Box<dyn Fn(Vec<u8>) -> Option<pallet_xcm::Event<Runtime>>>,
@@ -125,6 +126,7 @@ pub fn limited_reserve_transfer_assets_for_native_asset_works<
 				local_bridge_hub_para_id.into(),
 				included_head,
 				&alice,
+				&slot_durations,
 			);
 
 			// we calculate exact delivery fees _after_ sending the message by weighing the sent

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-rococo/tests/tests.rs

@@ -24,9 +24,14 @@ use bridge_hub_rococo_runtime::{
 	Executive, ExistentialDeposit, ParachainSystem, PolkadotXcm, Runtime, RuntimeCall,
 	RuntimeEvent, RuntimeOrigin, SessionKeys, SignedExtra, TransactionPayment, UncheckedExtrinsic,
 };
+use bridge_hub_test_utils::SlotDurations;
 use codec::{Decode, Encode};
 use frame_support::{dispatch::GetDispatchInfo, parameter_types, traits::ConstU8};
-use parachains_common::{rococo::fee::WeightToFee, AccountId, AuraId, Balance};
+use parachains_common::{
+	rococo::{consensus::RELAY_CHAIN_SLOT_DURATION_MILLIS, fee::WeightToFee},
+	AccountId, AuraId, Balance, SLOT_DURATION,
+};
+use sp_consensus_aura::SlotDuration;
 use sp_core::H160;
 use sp_keyring::AccountKeyring::Alice;
 use sp_runtime::{
@@ -95,6 +100,13 @@ fn collator_session_keys() -> bridge_hub_test_utils::CollatorSessionKeys<Runtime
 	)
 }
 
+fn slot_durations() -> SlotDurations {
+	SlotDurations {
+		relay: SlotDuration::from_millis(RELAY_CHAIN_SLOT_DURATION_MILLIS.into()),
+		para: SlotDuration::from_millis(SLOT_DURATION),
+	}
+}
+
 bridge_hub_test_utils::test_cases::include_teleports_for_native_asset_works!(
 	Runtime,
 	AllPalletsWithoutSystem,
@@ -103,6 +115,7 @@ bridge_hub_test_utils::test_cases::include_teleports_for_native_asset_works!(
 	WeightToFee,
 	ParachainSystem,
 	collator_session_keys(),
+	slot_durations(),
 	ExistentialDeposit::get(),
 	Box::new(|runtime_event_encoded: Vec<u8>| {
 		match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
@@ -264,6 +277,7 @@ mod bridge_hub_westend_tests {
 			ConstU8<2>,
 		>(
 			collator_session_keys(),
+			slot_durations(),
 			bp_bridge_hub_rococo::BRIDGE_HUB_ROCOCO_PARACHAIN_ID,
 			SIBLING_PARACHAIN_ID,
 			Box::new(|runtime_event_encoded: Vec<u8>| {
@@ -288,6 +302,7 @@ mod bridge_hub_westend_tests {
 		// from Westend
 		from_parachain::relayed_incoming_message_works::<RuntimeTestsAdapter>(
 			collator_session_keys(),
+			slot_durations(),
 			bp_bridge_hub_rococo::BRIDGE_HUB_ROCOCO_PARACHAIN_ID,
 			bp_bridge_hub_westend::BRIDGE_HUB_WESTEND_PARACHAIN_ID,
 			BridgeHubWestendChainId::get(),
@@ -304,6 +319,7 @@ mod bridge_hub_westend_tests {
 		// for Westend
 		from_parachain::complex_relay_extrinsic_works::<RuntimeTestsAdapter>(
 			collator_session_keys(),
+			slot_durations(),
 			bp_bridge_hub_rococo::BRIDGE_HUB_ROCOCO_PARACHAIN_ID,
 			bp_bridge_hub_westend::BRIDGE_HUB_WESTEND_PARACHAIN_ID,
 			SIBLING_PARACHAIN_ID,
@@ -459,6 +475,7 @@ mod bridge_hub_bulletin_tests {
 			ConstU8<2>,
 		>(
 			collator_session_keys(),
+			slot_durations(),
 			bp_bridge_hub_rococo::BRIDGE_HUB_ROCOCO_PARACHAIN_ID,
 			SIBLING_PARACHAIN_ID,
 			Box::new(|runtime_event_encoded: Vec<u8>| {
@@ -483,6 +500,7 @@ mod bridge_hub_bulletin_tests {
 		// from Bulletin
 		from_grandpa_chain::relayed_incoming_message_works::<RuntimeTestsAdapter>(
 			collator_session_keys(),
+			slot_durations(),
 			bp_bridge_hub_rococo::BRIDGE_HUB_ROCOCO_PARACHAIN_ID,
 			RococoBulletinChainId::get(),
 			SIBLING_PARACHAIN_ID,
@@ -498,6 +516,7 @@ mod bridge_hub_bulletin_tests {
 		// for Bulletin
 		from_grandpa_chain::complex_relay_extrinsic_works::<RuntimeTestsAdapter>(
 			collator_session_keys(),
+			slot_durations(),
 			bp_bridge_hub_rococo::BRIDGE_HUB_ROCOCO_PARACHAIN_ID,
 			SIBLING_PARACHAIN_ID,
 			RococoBulletinChainId::get(),

cumulus/parachains/runtimes/bridge-hubs/bridge-hub-westend/tests/tests.rs

@@ -18,7 +18,7 @@
 
 use bp_polkadot_core::Signature;
 use bridge_common_config::{DeliveryRewardInBalance, RequiredStakeForStakeAndSlash};
-use bridge_hub_test_utils::test_cases::from_parachain;
+use bridge_hub_test_utils::{test_cases::from_parachain, SlotDurations};
 use bridge_hub_westend_runtime::{
 	bridge_common_config, bridge_to_rococo_config,
 	xcm_config::{RelayNetwork, WestendLocation, XcmConfig},
@@ -33,7 +33,11 @@ use bridge_to_rococo_config::{
 };
 use codec::{Decode, Encode};
 use frame_support::{dispatch::GetDispatchInfo, parameter_types, traits::ConstU8};
-use parachains_common::{westend::fee::WeightToFee, AccountId, AuraId, Balance};
+use parachains_common::{
+	westend::{consensus::RELAY_CHAIN_SLOT_DURATION_MILLIS, fee::WeightToFee},
+	AccountId, AuraId, Balance, SLOT_DURATION,
+};
+use sp_consensus_aura::SlotDuration;
 use sp_keyring::AccountKeyring::Alice;
 use sp_runtime::{
 	generic::{Era, SignedPayload},
@@ -111,6 +115,13 @@ fn collator_session_keys() -> bridge_hub_test_utils::CollatorSessionKeys<Runtime
 	)
 }
 
+fn slot_durations() -> SlotDurations {
+	SlotDurations {
+		relay: SlotDuration::from_millis(RELAY_CHAIN_SLOT_DURATION_MILLIS.into()),
+		para: SlotDuration::from_millis(SLOT_DURATION),
+	}
+}
+
 bridge_hub_test_utils::test_cases::include_teleports_for_native_asset_works!(
 	Runtime,
 	AllPalletsWithoutSystem,
@@ -119,6 +130,7 @@ bridge_hub_test_utils::test_cases::include_teleports_for_native_asset_works!(
 	WeightToFee,
 	ParachainSystem,
 	collator_session_keys(),
+	slot_durations(),
 	ExistentialDeposit::get(),
 	Box::new(|runtime_event_encoded: Vec<u8>| {
 		match RuntimeEvent::decode(&mut &runtime_event_encoded[..]) {
@@ -229,6 +241,7 @@ fn message_dispatch_routing_works() {
 		ConstU8<2>,
 	>(
 		collator_session_keys(),
+		slot_durations(),
 		bp_bridge_hub_westend::BRIDGE_HUB_WESTEND_PARACHAIN_ID,
 		SIBLING_PARACHAIN_ID,
 		Box::new(|runtime_event_encoded: Vec<u8>| {
@@ -252,6 +265,7 @@ fn message_dispatch_routing_works() {
 fn relayed_incoming_message_works() {
 	from_parachain::relayed_incoming_message_works::<RuntimeTestsAdapter>(
 		collator_session_keys(),
+		slot_durations(),
 		bp_bridge_hub_westend::BRIDGE_HUB_WESTEND_PARACHAIN_ID,
 		bp_bridge_hub_rococo::BRIDGE_HUB_ROCOCO_PARACHAIN_ID,
 		BridgeHubRococoChainId::get(),
@@ -267,6 +281,7 @@ fn relayed_incoming_message_works() {
 pub fn complex_relay_extrinsic_works() {
 	from_parachain::complex_relay_extrinsic_works::<RuntimeTestsAdapter>(
 		collator_session_keys(),
+		slot_durations(),
 		bp_bridge_hub_westend::BRIDGE_HUB_WESTEND_PARACHAIN_ID,
 		bp_bridge_hub_rococo::BRIDGE_HUB_ROCOCO_PARACHAIN_ID,
 		SIBLING_PARACHAIN_ID,

cumulus/parachains/runtimes/bridge-hubs/test-utils/src/test_cases/from_grandpa_chain.rs

@@ -39,7 +39,7 @@ use bridge_runtime_common::{
 use frame_support::traits::{Get, OnFinalize, OnInitialize};
 use frame_system::pallet_prelude::BlockNumberFor;
 use parachains_runtimes_test_utils::{
-	AccountIdOf, BasicParachainRuntime, CollatorSessionKeys, RuntimeCallOf,
+	AccountIdOf, BasicParachainRuntime, CollatorSessionKeys, RuntimeCallOf, SlotDurations,
 };
 use sp_keyring::AccountKeyring::*;
 use sp_runtime::{traits::Header as HeaderT, AccountId32};
@@ -107,6 +107,7 @@ where
 /// Also verifies relayer transaction signed extensions work as intended.
 pub fn relayed_incoming_message_works<RuntimeHelper>(
 	collator_session_key: CollatorSessionKeys<RuntimeHelper::Runtime>,
+	slot_durations: SlotDurations,
 	runtime_para_id: u32,
 	bridged_chain_id: bp_runtime::ChainId,
 	sibling_parachain_id: u32,
@@ -136,6 +137,7 @@ pub fn relayed_incoming_message_works<RuntimeHelper>(
 		RuntimeHelper::MPI,
 	>(
 		collator_session_key,
+		slot_durations,
 		runtime_para_id,
 		sibling_parachain_id,
 		local_relay_chain_id,
@@ -205,6 +207,7 @@ pub fn relayed_incoming_message_works<RuntimeHelper>(
 /// Also verifies relayer transaction signed extensions work as intended.
 pub fn complex_relay_extrinsic_works<RuntimeHelper>(
 	collator_session_key: CollatorSessionKeys<RuntimeHelper::Runtime>,
+	slot_durations: SlotDurations,
 	runtime_para_id: u32,
 	sibling_parachain_id: u32,
 	bridged_chain_id: bp_runtime::ChainId,
@@ -237,6 +240,7 @@ pub fn complex_relay_extrinsic_works<RuntimeHelper>(
 		RuntimeHelper::MPI,
 	>(
 		collator_session_key,
+		slot_durations,
 		runtime_para_id,
 		sibling_parachain_id,
 		local_relay_chain_id,

cumulus/parachains/runtimes/bridge-hubs/test-utils/src/test_cases/from_parachain.rs

@@ -40,7 +40,7 @@ use bridge_runtime_common::{
 use frame_support::traits::{Get, OnFinalize, OnInitialize};
 use frame_system::pallet_prelude::BlockNumberFor;
 use parachains_runtimes_test_utils::{
-	AccountIdOf, BasicParachainRuntime, CollatorSessionKeys, RuntimeCallOf,
+	AccountIdOf, BasicParachainRuntime, CollatorSessionKeys, RuntimeCallOf, SlotDurations,
 };
 use sp_keyring::AccountKeyring::*;
 use sp_runtime::{traits::Header as HeaderT, AccountId32};
@@ -112,6 +112,7 @@ where
 /// Also verifies relayer transaction signed extensions work as intended.
 pub fn relayed_incoming_message_works<RuntimeHelper>(
 	collator_session_key: CollatorSessionKeys<RuntimeHelper::Runtime>,
+	slot_durations: SlotDurations,
 	runtime_para_id: u32,
 	bridged_para_id: u32,
 	bridged_chain_id: bp_runtime::ChainId,
@@ -146,6 +147,7 @@ pub fn relayed_incoming_message_works<RuntimeHelper>(
 		RuntimeHelper::MPI,
 	>(
 		collator_session_key,
+		slot_durations,
 		runtime_para_id,
 		sibling_parachain_id,
 		local_relay_chain_id,
@@ -244,6 +246,7 @@ pub fn relayed_incoming_message_works<RuntimeHelper>(
 /// Also verifies relayer transaction signed extensions work as intended.
 pub fn complex_relay_extrinsic_works<RuntimeHelper>(
 	collator_session_key: CollatorSessionKeys<RuntimeHelper::Runtime>,
+	slot_durations: SlotDurations,
 	runtime_para_id: u32,
 	bridged_para_id: u32,
 	sibling_parachain_id: u32,
@@ -281,6 +284,7 @@ pub fn complex_relay_extrinsic_works<RuntimeHelper>(
 		RuntimeHelper::MPI,
 	>(
 		collator_session_key,
+		slot_durations,
 		runtime_para_id,
 		sibling_parachain_id,
 		local_relay_chain_id,

cumulus/parachains/runtimes/bridge-hubs/test-utils/src/test_cases/helpers.rs

@@ -31,7 +31,7 @@ use frame_system::pallet_prelude::BlockNumberFor;
 use pallet_bridge_grandpa::{BridgedBlockHash, BridgedHeader};
 use parachains_common::AccountId;
 use parachains_runtimes_test_utils::{
-	mock_open_hrmp_channel, AccountIdOf, CollatorSessionKeys, RuntimeCallOf,
+	mock_open_hrmp_channel, AccountIdOf, CollatorSessionKeys, RuntimeCallOf, SlotDurations,
 };
 use sp_core::Get;
 use sp_keyring::AccountKeyring::*;
@@ -220,6 +220,7 @@ pub fn relayer_id_at_bridged_chain<Runtime: pallet_bridge_messages::Config<MPI>,
 /// with proofs (finality, message) independently submitted.
 pub fn relayed_incoming_message_works<Runtime, AllPalletsWithoutSystem, MPI>(
 	collator_session_key: CollatorSessionKeys<Runtime>,
+	slot_durations: SlotDurations,
 	runtime_para_id: u32,
 	sibling_parachain_id: u32,
 	local_relay_chain_id: NetworkId,
@@ -272,6 +273,7 @@ pub fn relayed_incoming_message_works<Runtime, AllPalletsWithoutSystem, MPI>(
 				sibling_parachain_id.into(),
 				included_head,
 				&alice,
+				&slot_durations,
 			);
 
 			// set up relayer details and proofs

cumulus/parachains/runtimes/bridge-hubs/test-utils/src/test_cases/mod.rs

@@ -45,7 +45,7 @@ use frame_system::pallet_prelude::BlockNumberFor;
 use parachains_common::AccountId;
 use parachains_runtimes_test_utils::{
 	mock_open_hrmp_channel, AccountIdOf, BalanceOf, CollatorSessionKeys, ExtBuilder, RuntimeCallOf,
-	XcmReceivedFrom,
+	SlotDurations, XcmReceivedFrom,
 };
 use sp_runtime::{traits::Zero, AccountId32};
 use xcm::{latest::prelude::*, AlwaysLatest};
@@ -419,6 +419,7 @@ pub fn message_dispatch_routing_works<
 	NetworkDistanceAsParentCount,
 >(
 	collator_session_key: CollatorSessionKeys<Runtime>,
+	slot_durations: SlotDurations,
 	runtime_para_id: u32,
 	sibling_parachain_id: u32,
 	unwrap_cumulus_pallet_parachain_system_event: Box<
@@ -529,6 +530,7 @@ pub fn message_dispatch_routing_works<
 			sibling_parachain_id.into(),
 			included_head,
 			&alice,
+			&slot_durations,
 		);
 		let result =
 			<<Runtime as BridgeMessagesConfig<MessagesPalletInstance>>::MessageDispatch>::dispatch(

cumulus/parachains/runtimes/test-utils/src/lib.rs

@@ -29,7 +29,6 @@ use frame_support::{
 	weights::Weight,
 };
 use frame_system::pallet_prelude::{BlockNumberFor, HeaderFor};
-use parachains_common::SLOT_DURATION;
 use polkadot_parachain_primitives::primitives::{
 	HeadData, HrmpChannelId, RelayChainBlockNumber, XcmpMessageFormat,
 };
@@ -115,6 +114,11 @@ impl<Runtime: frame_system::Config + pallet_balances::Config + pallet_session::C
 	}
 }
 
+pub struct SlotDurations {
+	pub relay: SlotDuration,
+	pub para: SlotDuration,
+}
+
 /// A set of traits for a minimal parachain runtime, that may be used in conjunction with the
 /// `ExtBuilder` and the `RuntimeHelper`.
 pub trait BasicParachainRuntime:
@@ -335,6 +339,7 @@ impl<
 		open_hrmp_channel: Option<(u32, u32)>,
 		included_head: HeaderFor<Runtime>,
 		slot_digest: &[u8],
+		slot_durations: &SlotDurations,
 	) -> DispatchResult
 	where
 		HrmpChannelOpener: frame_support::inherent::ProvideInherent<
@@ -348,6 +353,7 @@ impl<
 				target_para_id.into(),
 				included_head,
 				slot_digest,
+				slot_durations,
 			);
 		}
 
@@ -493,12 +499,12 @@ pub fn mock_open_hrmp_channel<
 	recipient: ParaId,
 	included_head: HeaderFor<C>,
 	mut slot_digest: &[u8],
+	slot_durations: &SlotDurations,
 ) {
-	const RELAY_CHAIN_SLOT_DURATION: SlotDuration = SlotDuration::from_millis(6000);
 	let slot = Slot::decode(&mut slot_digest).expect("failed to decode digest");
 	// Convert para slot to relay chain.
-	let timestamp = slot.saturating_mul(SLOT_DURATION);
-	let relay_slot = Slot::from_timestamp(timestamp.into(), RELAY_CHAIN_SLOT_DURATION);
+	let timestamp = slot.saturating_mul(slot_durations.para.as_millis());
+	let relay_slot = Slot::from_timestamp(timestamp.into(), slot_durations.relay);
 
 	let n = 1_u32;
 	let mut sproof_builder = RelayStateSproofBuilder {