fix(rpc): eth_call over-reports gas for native precompiles

CHANGELOG.md

@@ -61,6 +61,7 @@
 - [\#1061](https://github.com/cosmos/evm/pull/1061) Block nested ICS20 forwarding in source callbacks.
 - [\#1050](https://github.com/cosmos/evm/pull/1050) Align precompile gas calculation with expected EVM gas semantics.
 - [\#1107](https://github.com/cosmos/evm/pull/1107) Skip StateDB commit error transactions during receipt conversion to prevent `invalid message index` errors in block RPCs.
+- [\#1183](https://github.com/cosmos/evm/pull/1183) Align eth_call's KV gas accounting with deliverTx so it stops rejecting valid estimateGas results for native precompile txs.
 
 
 ## v0.6.0

tests/integration/x/vm/test_grpc_query.go

@@ -18,6 +18,7 @@ import (
 	"github.com/holiman/uint256"
 	"github.com/stretchr/testify/require"
 
+	bankprecompile "github.com/cosmos/evm/precompiles/bank"
 	"github.com/cosmos/evm/server/config"
 	testconstants "github.com/cosmos/evm/testutil/constants"
 	"github.com/cosmos/evm/testutil/integration/evm/factory"
@@ -2211,6 +2212,40 @@ func (s *KeeperTestSuite) TestEthCall() {
 	}
 }
 
+// TestEthCallGasMatchesDeliverTxForNativePrecompile asserts that EthCall and
+// a broadcasted tx report the same GasUsed when targeting a native precompile,
+// covering the BuildEvmExecutionCtx call added to EthCall.
+func (s *KeeperTestSuite) TestEthCallGasMatchesDeliverTxForNativePrecompile() {
+	s.SetupTest()
+
+	sender := s.Keyring.GetKey(0)
+	to := common.HexToAddress(types.BankPrecompileAddress)
+	data, err := bankprecompile.ABI.Pack(bankprecompile.BalancesMethod, sender.Addr)
+	s.Require().NoError(err)
+
+	gas := hexutil.Uint64(500_000)
+	args, err := json.Marshal(&types.TransactionArgs{
+		From: &sender.Addr, To: &to, Data: (*hexutil.Bytes)(&data), Gas: &gas,
+	})
+	s.Require().NoError(err)
+
+	callRes, err := s.Network.GetEvmClient().EthCall(s.Network.GetContext(), &types.EthCallRequest{
+		Args: args, GasCap: config.DefaultGasCap,
+	})
+	s.Require().NoError(err)
+	s.Require().Empty(callRes.VmError)
+
+	txRes, err := s.Factory.ExecuteEthTx(sender.Priv, types.EvmTxArgs{
+		To: &to, GasLimit: uint64(gas), Input: data,
+	})
+	s.Require().NoError(err)
+	deliverRes, err := types.DecodeTxResponse(txRes.Data)
+	s.Require().NoError(err)
+	s.Require().Empty(deliverRes.VmError)
+
+	s.Require().Equal(deliverRes.GasUsed, callRes.GasUsed)
+}
+
 func (s *KeeperTestSuite) TestBalance() {
 	testCases := []struct {
 		name        string

x/vm/keeper/grpc_query.go

@@ -268,6 +268,12 @@ func (k Keeper) EthCall(c context.Context, req *types.EthCallRequest) (_ *types.
 		}
 	}
 
+	// Align eth_call's KV gas accounting with deliverTx: clear KV/transient gas
+	// configs so EVM-internal cosmos-sdk store ops (e.g. precompile.FlushToCacheCtx)
+	// don't charge gas. Otherwise eth_call would report a stricter floor than
+	// real broadcast for txs reaching native precompiles.
+	ctx = evmante.BuildEvmExecutionCtx(ctx)
+
 	var args types.TransactionArgs
 	err = json.Unmarshal(req.Args, &args)
 	if err != nil {

x/vm/keeper/grpc_query_test.go

@@ -0,0 +1,24 @@
+package keeper
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	storetypes "github.com/cosmos/cosmos-sdk/store/v2/types"
+	sdk "github.com/cosmos/cosmos-sdk/types"
+)
+
+// buildTraceCtx must zero KV gas configs so simulation matches deliverTx
+// (whose ante also zeroes KV via BuildEvmExecutionCtx). SLOAD/SSTORE gas
+// accounting then remains opcode-driven and does not consume KV gas, and
+// pre-precompile cosmos-sdk store ops (e.g. stateDB.FlushToCacheCtx) are
+// free — same as on real chain.
+func TestBuildTraceCtxZeroesKVGasConfig(t *testing.T) {
+	parent := sdk.Context{}.
+		WithKVGasConfig(storetypes.KVGasConfig()).
+		WithTransientKVGasConfig(storetypes.TransientGasConfig())
+	traceCtx := buildTraceCtx(parent, 1_000_000)
+	require.Equal(t, storetypes.GasConfig{}, traceCtx.KVGasConfig())
+	require.Equal(t, storetypes.GasConfig{}, traceCtx.TransientKVGasConfig())
+}