Fix Native to Eth conversion in EVM gas fee estimation

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

@@ -2189,6 +2189,12 @@ impl_runtime_apis! {
 			Revive::evm_balance(&address)
 		}
 
+		fn block_gas_limit() -> U256 {
+			let weight = RuntimeBlockWeights::get().max_block;
+			let fee = TransactionPayment::weight_to_fee(weight);
+			Revive::evm_fee_to_gas(fee)
+		}
+
 		fn nonce(address: H160) -> Nonce {
 			let account = <Runtime as pallet_revive::Config>::AddressMapper::to_account_id(&address);
 			System::account_nonce(account)

substrate/bin/node/runtime/src/lib.rs

@@ -3301,6 +3301,12 @@ impl_runtime_apis! {
 			Revive::evm_balance(&address)
 		}
 
+		fn block_gas_limit() -> U256 {
+			let weight = RuntimeBlockWeights::get().max_block;
+			let fee = TransactionPayment::weight_to_fee(weight);
+			Revive::evm_fee_to_gas(fee)
+		}
+
 		fn nonce(address: H160) -> Nonce {
 			let account = <Runtime as pallet_revive::Config>::AddressMapper::to_account_id(&address);
 			System::account_nonce(account)

substrate/frame/revive/rpc/src/client.rs

@@ -18,7 +18,6 @@
 //! and is used by the rpc server to query and send transactions to the substrate chain.
 use crate::{
 	extract_receipts_from_block,
-	runtime::gas_from_fee,
 	subxt_client::{
 		revive::calls::types::EthTransact, runtime_types::pallet_revive::storage::ContractInfo,
 	},
@@ -649,8 +648,7 @@ impl Client {
 		hydrated_transactions: bool,
 	) -> Result<Block, ClientError> {
 		let runtime_api = self.api.runtime_api().at(block.hash());
-		let max_fee = Self::weight_to_fee(&runtime_api, self.max_block_weight()).await?;
-		let gas_limit = gas_from_fee(max_fee);
+		let gas_limit = Self::block_gas_limit(&runtime_api).await?;
 
 		let header = block.header();
 		let timestamp = extract_block_timestamp(&block).await.unwrap_or_default();
@@ -695,16 +693,13 @@ impl Client {
 	}
 
 	/// Convert a weight to a fee.
-	async fn weight_to_fee(
+	async fn block_gas_limit(
 		runtime_api: &subxt::runtime_api::RuntimeApi<SrcChainConfig, OnlineClient<SrcChainConfig>>,
-		weight: Weight,
-	) -> Result<Balance, ClientError> {
-		let payload = subxt_client::apis()
-			.transaction_payment_api()
-			.query_weight_to_fee(weight.into());
+	) -> Result<U256, ClientError> {
+		let payload = subxt_client::apis().revive_api().block_gas_limit();
 
-		let fee = runtime_api.call(payload).await?;
-		Ok(fee)
+		let gas_limit = runtime_api.call(payload).await?;
+		Ok(*gas_limit)
 	}
 
 	/// Get the chain ID.

substrate/frame/revive/src/evm/runtime.rs

@@ -20,7 +20,7 @@ use crate::{
 		api::{GenericTransaction, TransactionSigned},
 		GasEncoder,
 	},
-	AccountIdOf, AddressMapper, BalanceOf, Config, MomentOf, Weight, LOG_TARGET,
+	AccountIdOf, AddressMapper, BalanceOf, Config, MomentOf, Pallet, LOG_TARGET,
 };
 use alloc::vec::Vec;
 use codec::{Decode, Encode};
@@ -34,8 +34,8 @@ use sp_core::{Get, H256, U256};
 use sp_runtime::{
 	generic::{self, CheckedExtrinsic, ExtrinsicFormat},
 	traits::{
-		self, AtLeast32BitUnsigned, Checkable, Dispatchable, ExtrinsicLike, ExtrinsicMetadata,
-		IdentifyAccount, Member, TransactionExtension,
+		self, Checkable, Dispatchable, ExtrinsicLike, ExtrinsicMetadata, IdentifyAccount, Member,
+		TransactionExtension,
 	},
 	transaction_validity::{InvalidTransaction, TransactionValidityError},
 	OpaqueExtrinsic, RuntimeDebug, Saturating,
@@ -56,34 +56,6 @@ type CallOf<T> = <T as frame_system::Config>::RuntimeCall;
 /// - Not too low, enabling users to adjust the gas price to define a tip.
 pub const GAS_PRICE: u32 = 1_000u32;
 
-/// Convert a `Balance` into a gas value, using the fixed `GAS_PRICE`.
-/// The gas is calculated as `balance / GAS_PRICE`, rounded up to the nearest integer.
-pub fn gas_from_fee<Balance>(fee: Balance) -> U256
-where
-	u32: Into<Balance>,
-	Balance: Into<U256> + AtLeast32BitUnsigned + Copy,
-{
-	let gas_price = GAS_PRICE.into();
-	let remainder = fee % gas_price;
-	if remainder.is_zero() {
-		(fee / gas_price).into()
-	} else {
-		(fee.saturating_add(gas_price) / gas_price).into()
-	}
-}
-
-/// Convert a `Weight` into a gas value, using the fixed `GAS_PRICE`.
-/// and the `Config::WeightPrice` to compute the fee.
-/// The gas is calculated as `fee / GAS_PRICE`, rounded up to the nearest integer.
-pub fn gas_from_weight<T: Config>(weight: Weight) -> U256
-where
-	BalanceOf<T>: Into<U256>,
-{
-	use sp_runtime::traits::Convert;
-	let fee: BalanceOf<T> = T::WeightPrice::convert(weight);
-	gas_from_fee(fee)
-}
-
 /// Wraps [`generic::UncheckedExtrinsic`] to support checking unsigned
 /// [`crate::Call::eth_transact`] extrinsic.
 #[derive(Encode, Decode, Clone, PartialEq, Eq, RuntimeDebug)]
@@ -393,17 +365,17 @@ pub trait EthExtra {
 		let nonce = nonce.unwrap_or_default().try_into().map_err(|_| InvalidTransaction::Call)?;
 
 		// Fees calculated with the fixed `GAS_PRICE`
-		// When we dry-run the transaction, we set the gas to `Fee / GAS_PRICE`
+		// When we dry-run the transaction, we set the gas to `fee / GAS_PRICE`
 		let eth_fee_no_tip = U256::from(GAS_PRICE)
 			.saturating_mul(gas)
 			.try_into()
 			.map_err(|_| InvalidTransaction::Call)?;
 
-		// Fees with the actual gas_price from the transaction.
-		let eth_fee: BalanceOf<Self::Config> = U256::from(gas_price.unwrap_or_default())
-			.saturating_mul(gas)
-			.try_into()
-			.map_err(|_| InvalidTransaction::Call)?;
+		// Fees calculated from the gas and gas_price of the transaction.
+		let eth_fee = Pallet::<Self::Config>::convert_evm_to_native(
+			U256::from(gas_price.unwrap_or_default()).saturating_mul(gas),
+		)
+		.map_err(|_| InvalidTransaction::Call)?;
 
 		let info = call.get_dispatch_info();
 		let function: CallOf<Self::Config> = call.into();

substrate/frame/revive/src/lib.rs

@@ -41,10 +41,7 @@ pub mod tracing;
 pub mod weights;
 
 use crate::{
-	evm::{
-		runtime::{gas_from_fee, GAS_PRICE},
-		GasEncoder, GenericTransaction,
-	},
+	evm::{runtime::GAS_PRICE, GasEncoder, GenericTransaction},
 	exec::{AccountIdOf, ExecError, Executable, Ext, Key, Stack as ExecStack},
 	gas::GasMeter,
 	storage::{meter::Meter as StorageMeter, ContractInfo, DeletionQueueManager},
@@ -1297,7 +1294,7 @@ where
 				0u32.into(),
 			)
 			.into();
-			let eth_gas = gas_from_fee(fee);
+			let eth_gas = Self::evm_fee_to_gas(fee);
 			let eth_gas =
 				T::EthGasEncoder::encode(eth_gas, result.gas_required, result.storage_deposit);
 
@@ -1319,6 +1316,19 @@ where
 		Self::convert_native_to_evm(T::Currency::reducible_balance(&account, Preserve, Polite))
 	}
 
+	/// Convert an EVM fee into a gas value, using the fixed `GAS_PRICE`.
+	/// The gas is calculated as `balance / GAS_PRICE`, rounded up to the nearest integer.
+	pub fn evm_fee_to_gas(fee: BalanceOf<T>) -> U256 {
+		let fee = Self::convert_native_to_evm(fee);
+		let gas_price = GAS_PRICE.into();
+		let remainder = fee % gas_price;
+		if remainder.is_zero() {
+			(fee / gas_price).into()
+		} else {
+			(fee.saturating_add(gas_price) / gas_price).into()
+		}
+	}
+
 	/// A generalized version of [`Self::upload_code`].
 	///
 	/// It is identical to [`Self::upload_code`] and only differs in the information it returns.
@@ -1374,7 +1384,7 @@ where
 	}
 
 	/// Convert a native balance to EVM balance.
-	fn convert_native_to_evm(value: BalanceOf<T>) -> U256 {
+	pub fn convert_native_to_evm(value: BalanceOf<T>) -> U256 {
 		value.into().saturating_mul(T::NativeToEthRatio::get().into())
 	}
 
@@ -1417,6 +1427,9 @@ sp_api::decl_runtime_apis! {
 		Nonce: Codec,
 		BlockNumber: Codec,
 	{
+		/// Returns the block gas limit.
+		fn block_gas_limit() -> U256;
+
 		/// Returns the free balance of the given `[H160]` address, using EVM decimals.
 		fn balance(address: H160) -> U256;