feat(levm): implement EIP7691 - Blob throughput increase

crates/common/types/block.rs

@@ -340,7 +340,11 @@ fn check_gas_limit(gas_limit: u64, parent_gas_limit: u64) -> bool {
         && gas_limit >= GAS_LIMIT_MINIMUM
 }
 
-// Calculates the base fee per blob gas for the current block based on it's parent excess blob gas
+/// Calculates the base fee per blob gas for the current block based on
+/// it's parent excess blob gas.
+/// NOTE: BLOB_BASE_FEE_UPDATE_FRACTION has a different value after
+/// prague fork. See
+/// [EIP-7691](https://eips.ethereum.org/EIPS/eip-7691#specification).
 pub fn calculate_base_fee_per_blob_gas(parent_excess_blob_gas: u64) -> u64 {
     fake_exponential(
         MIN_BASE_FEE_PER_BLOB_GAS,

crates/vm/levm/README.md

@@ -6,7 +6,7 @@ Implementation of a simple Ethereum Virtual Machine in Rust.
 
 | Fork           | Status |
 | -------------- | ------ |
-| Prague         | 🏗️     |
+| Prague         | ✅️     |
 | Cancun         | ✅     |
 | Shanghai       | ✅     |
 | Paris (Merge)  | ✅     |
@@ -78,14 +78,16 @@ There are a lot of EIPs schedule to include in this upgrade but for `levm` we'll
 
 - EIP-2537: Precompile for BLS12-381 curve operations
 - EIP-7623: Increase calldata cost
+- EIP-7691: Blob throughput increase
 - EIP-7702: Set EOA account code
 
 | Task Description          | Status |
 | ------------------------- | ------ |
 | Implement EIP-2537        | ✅     |
 | Implement EIP-7623        | ✅     |
-| Implement EIP-7702        | ✅     |
-| Make Prague EF tests pass | ❌     |
+| Implement EIP-7691        | ✅️     |
+| Implement EIP-7702        | ✅️     |
+| Make Prague EF tests pass | ✅     |
 
 ### Milestone 5: Integrate `ethrex L2` <> `levm`
 

crates/vm/levm/src/constants.rs

@@ -43,13 +43,24 @@ pub mod create_opcode {
 }
 
 pub const VERSIONED_HASH_VERSION_KZG: u8 = 0x01;
-pub const MAX_BLOB_NUMBER_PER_BLOCK: usize = 6;
 
 // Blob constants
 pub const TARGET_BLOB_GAS_PER_BLOCK: U256 = U256([393216, 0, 0, 0]); // TARGET_BLOB_NUMBER_PER_BLOCK * GAS_PER_BLOB
+pub const TARGET_BLOB_GAS_PER_BLOCK_PECTRA: U256 = U256([786432, 0, 0, 0]); // TARGET_BLOB_NUMBER_PER_BLOCK * GAS_PER_BLOB
+
 pub const MIN_BASE_FEE_PER_BLOB_GAS: U256 = U256::one();
+
+// WARNING: Do _not_ use the BLOB_BASE_FEE_UPDATE_FRACTION_* family of
+// constants as is. Use the `get_blob_base_fee_update_fraction_value`
+// function instead
 pub const BLOB_BASE_FEE_UPDATE_FRACTION: U256 = U256([3338477, 0, 0, 0]);
+pub const BLOB_BASE_FEE_UPDATE_FRACTION_PRAGUE: U256 = U256([5007716, 0, 0, 0]); // Defined in [EIP-7691](https://eips.ethereum.org/EIPS/eip-7691)
+
+// WARNING: Do _not_ use the MAX_BLOB_COUNT_* family of constants as
+// is. Use the `max_blobs_per_block` function instead
 pub const MAX_BLOB_COUNT: usize = 6;
+pub const MAX_BLOB_COUNT_ELECTRA: usize = 9;
+
 pub const VALID_BLOB_PREFIXES: [u8; 2] = [0x01, 0x02];
 
 // Block constants

crates/vm/levm/src/vm.rs

@@ -741,7 +741,7 @@ impl VM {
         fake_exponential(
             MIN_BASE_FEE_PER_BLOB_GAS,
             self.env.block_excess_blob_gas.unwrap_or_default(),
-            BLOB_BASE_FEE_UPDATE_FRACTION,
+            get_blob_base_fee_update_fraction_value(self.env.spec_id),
         )
     }
 
@@ -934,7 +934,7 @@ impl VM {
             }
 
             // (14) TYPE_3_TX_BLOB_COUNT_EXCEEDED
-            if blob_hashes.len() > MAX_BLOB_COUNT {
+            if blob_hashes.len() > max_blobs_per_block(self.env.spec_id) {
                 return Err(VMError::TxValidation(
                     TxValidationError::Type3TxBlobCountExceeded,
                 ));
@@ -1684,3 +1684,29 @@ fn eip7702_recover_address(auth_tuple: &AuthorizationTuple) -> Result<Option<Add
         .map_err(|_| VMError::Internal(InternalError::ConversionError))?;
     Ok(Some(Address::from_slice(&authority_address_bytes)))
 }
+
+/// After EIP-7691 the maximum number of blob hashes changes. For more
+/// information see
+/// [EIP-7691](https://eips.ethereum.org/EIPS/eip-7691#specification).
+pub const fn max_blobs_per_block(specid: SpecId) -> usize {
+    match specid {
+        SpecId::PRAGUE => MAX_BLOB_COUNT_ELECTRA,
+        SpecId::PRAGUE_EOF => MAX_BLOB_COUNT_ELECTRA,
+        _ => MAX_BLOB_COUNT,
+    }
+}
+
+/// According to EIP-7691
+/// (https://eips.ethereum.org/EIPS/eip-7691#specification):
+///
+/// "These changes imply that get_base_fee_per_blob_gas and
+/// calc_excess_blob_gas functions defined in EIP-4844 use the new
+/// values for the first block of the fork (and for all subsequent
+/// blocks)."
+pub const fn get_blob_base_fee_update_fraction_value(specid: SpecId) -> U256 {
+    match specid {
+        SpecId::PRAGUE => BLOB_BASE_FEE_UPDATE_FRACTION_PRAGUE,
+        SpecId::PRAGUE_EOF => BLOB_BASE_FEE_UPDATE_FRACTION_PRAGUE,
+        _ => BLOB_BASE_FEE_UPDATE_FRACTION,
+    }
+}