EIP-7742: Uncouple blob limits per block across CL and EL

pysetup/spec_builders/electra.py

@@ -30,7 +30,8 @@ class NoopExecutionEngine(ExecutionEngine):
     def notify_new_payload(self: ExecutionEngine,
                            execution_payload: ExecutionPayload,
                            parent_beacon_block_root: Root,
-                           execution_requests_list: Sequence[bytes]) -> bool:
+                           execution_requests_list: Sequence[bytes],
+                           target_blobs_per_block: uint64) -> bool:
         return True
 
     def notify_forkchoice_updated(self: ExecutionEngine,
@@ -46,7 +47,9 @@ def get_payload(self: ExecutionEngine, payload_id: PayloadId) -> GetPayloadRespo
 
     def is_valid_block_hash(self: ExecutionEngine,
                             execution_payload: ExecutionPayload,
-                            parent_beacon_block_root: Root) -> bool:
+                            parent_beacon_block_root: Root,
+                            execution_requests_list: Sequence[bytes],
+                            target_blobs_per_block: uint64) -> bool:
         return True
 
     def is_valid_versioned_hashes(self: ExecutionEngine, new_payload_request: NewPayloadRequest) -> bool:

specs/_features/eip7594/beacon-chain.md

@@ -53,6 +53,7 @@ def process_execution_payload(state: BeaconState, body: BeaconBlockBody, executi
             versioned_hashes=versioned_hashes,
             parent_beacon_block_root=state.latest_block_header.parent_root,
             execution_requests=body.execution_requests,
+            target_blobs_per_block=MAX_BLOBS_PER_BLOCK // 2,
         )
     )
     # Cache execution payload header

specs/_features/eip7732/beacon-chain.md

@@ -705,6 +705,7 @@ def process_execution_payload(state: BeaconState,
                 versioned_hashes=versioned_hashes,
                 parent_beacon_block_root=state.latest_block_header.parent_root,
                 execution_requests=requests,
+                target_blobs_per_block=MAX_BLOBS_PER_BLOCK // 2,
             )
         )
 

specs/electra/beacon-chain.md

@@ -79,6 +79,7 @@
     - [Request data](#request-data)
       - [Modified `NewPayloadRequest`](#modified-newpayloadrequest)
     - [Engine APIs](#engine-apis)
+      - [Modified `is_valid_block_hash`](#modified-is_valid_block_hash)
       - [Modified `notify_new_payload`](#modified-notify_new_payload)
       - [Modified `verify_and_notify_new_payload`](#modified-verify_and_notify_new_payload)
   - [Block processing](#block-processing)
@@ -1003,30 +1004,51 @@ class NewPayloadRequest(object):
     versioned_hashes: Sequence[VersionedHash]
     parent_beacon_block_root: Root
     execution_requests: ExecutionRequests  # [New in Electra]
+    target_blobs_per_block: uint64  # [New in Electra:EIP7742]
 ```
 
 #### Engine APIs
 
+##### Modified `is_valid_block_hash`
+
+*Note*: The function `is_valid_block_hash` is modified to include the additional
+`execution_requests_list` and `target_blobs_per_block` parameters in Electra.
+
+```python
+def is_valid_block_hash(self: ExecutionEngine,
+                        execution_payload: ExecutionPayload,
+                        parent_beacon_block_root: Root,
+                        execution_requests_list: Sequence[bytes],
+                        target_blobs_per_block: uint64) -> bool:
+    """
+    Return ``True`` if and only if ``execution_payload.block_hash`` is computed correctly.
+    """
+    ...
+```
+
 ##### Modified `notify_new_payload`
 
-*Note*: The function `notify_new_payload` is modified to include the additional `execution_requests` parameter in Electra.
+*Note*: The function `notify_new_payload` is modified to include the additional
+`execution_requests_list` and `target_blobs_per_block` parameters in Electra.
 
 ```python
 def notify_new_payload(self: ExecutionEngine,
                        execution_payload: ExecutionPayload,
                        parent_beacon_block_root: Root,
-                       execution_requests_list: Sequence[bytes]) -> bool:
+                       execution_requests_list: Sequence[bytes],
+                       target_blobs_per_block: uint64) -> bool:
     """
-    Return ``True`` if and only if ``execution_payload`` and ``execution_requests``
+    Return ``True`` if and only if ``execution_payload`` and ``execution_requests_list``
     are valid with respect to ``self.execution_state``.
     """
     ...
 ```
 
 ##### Modified `verify_and_notify_new_payload`
 
-*Note*: The function `verify_and_notify_new_payload` is modified to pass the additional parameter `execution_requests`
-when calling `notify_new_payload` in Electra.
+*Note*: The function `verify_and_notify_new_payload` is modified to pass the additional parameters
+`execution_requests_list` and `target_blobs_per_block` when calling `is_valid_block_hash` and
+`notify_new_payload` in Electra.
 
 ```python
 def verify_and_notify_new_payload(self: ExecutionEngine,
@@ -1037,11 +1059,17 @@ def verify_and_notify_new_payload(self: ExecutionEngine,
     execution_payload = new_payload_request.execution_payload
     parent_beacon_block_root = new_payload_request.parent_beacon_block_root
     execution_requests_list = get_execution_requests_list(new_payload_request.execution_requests)  # [New in Electra]
+    target_blobs_per_block = new_payload_request.target_blobs_per_block  # [New in Electra:EIP7742]
 
     if b'' in execution_payload.transactions:
         return False
 
-    if not self.is_valid_block_hash(execution_payload, parent_beacon_block_root):
+    # [Modified in Electra]
+    if not self.is_valid_block_hash(
+            execution_payload,
+            parent_beacon_block_root,
+            execution_requests_list,
+            target_blobs_per_block):
         return False
 
     if not self.is_valid_versioned_hashes(new_payload_request):
@@ -1051,7 +1079,8 @@ def verify_and_notify_new_payload(self: ExecutionEngine,
     if not self.notify_new_payload(
             execution_payload,
             parent_beacon_block_root,
-            execution_requests_list):
+            execution_requests_list,
+            target_blobs_per_block):
         return False
 
     return True
@@ -1213,6 +1242,7 @@ def process_execution_payload(state: BeaconState, body: BeaconBlockBody, executi
             versioned_hashes=versioned_hashes,
             parent_beacon_block_root=state.latest_block_header.parent_root,
             execution_requests=body.execution_requests,  # [New in Electra]
+            target_blobs_per_block=MAX_BLOBS_PER_BLOCK // 2,  # [New in Electra:EIP7742]
         )
     )
     # Cache execution payload header

specs/electra/fork-choice.md

@@ -0,0 +1,38 @@
+# Electra -- Fork Choice
+
+## Table of contents
+<!-- TOC -->
+<!-- START doctoc generated TOC please keep comment here to allow auto update -->
+<!-- DON'T EDIT THIS SECTION, INSTEAD RE-RUN doctoc TO UPDATE -->
+
+- [Introduction](#introduction)
+- [Containers](#containers)
+- [Helpers](#helpers)
+  - [Extended `PayloadAttributes`](#extended-payloadattributes)
+
+<!-- END doctoc generated TOC please keep comment here to allow auto update -->
+<!-- /TOC -->
+
+## Introduction
+
+This is the modification of the fork choice accompanying the Electra upgrade.
+
+## Containers
+
+## Helpers
+
+### Extended `PayloadAttributes`
+
+*Note*: `PayloadAttributes` is extended with the target/maximum number of blobs per block.
+
+```python
+@dataclass
+class PayloadAttributes(object):
+    timestamp: uint64
+    prev_randao: Bytes32
+    suggested_fee_recipient: ExecutionAddress
+    withdrawals: Sequence[Withdrawal]
+    parent_beacon_block_root: Root
+    target_blobs_per_block: uint64  # [New in Electra:EIP7742]
+    max_blobs_per_block: uint64  # [New in Electra:EIP7742]
+```

specs/electra/validator.md

@@ -176,6 +176,8 @@ def prepare_execution_payload(state: BeaconState,
         suggested_fee_recipient=suggested_fee_recipient,
         withdrawals=withdrawals,
         parent_beacon_block_root=hash_tree_root(state.latest_block_header),
+        target_blobs_per_block=MAX_BLOBS_PER_BLOCK // 2,  # [New in Electra:EIP7742]
+        max_blobs_per_block=MAX_BLOBS_PER_BLOCK,  # [New in Electra:EIP7742]
     )
     return execution_engine.notify_forkchoice_updated(
         head_block_hash=parent_hash,