Asynchronous Backing MegaPR

node/core/backing/src/lib.rs

@@ -777,7 +777,7 @@ async fn prospective_parachains_mode<Context>(
 		.map_err(Error::RuntimeApiUnavailable)?
 		.map_err(Error::FetchRuntimeApiVersion)?;
 
-	if version == 3 {
+	if version >= RuntimeApiRequest::VALIDITY_CONSTRAINTS {
 		Ok(ProspectiveParachainsMode::Enabled)
 	} else {
 		if version != 2 {

node/core/provisioner/src/lib.rs

@@ -201,7 +201,7 @@ async fn prospective_parachains_mode(
 
 	let version = rx.await.map_err(Error::CanceledRuntimeApiVersion)?.map_err(Error::Runtime)?;
 
-	if version == 3 {
+	if version >= RuntimeApiRequest::VALIDITY_CONSTRAINTS {
 		Ok(ProspectiveParachainsMode::Enabled)
 	} else {
 		if version != 2 {

node/subsystem-types/src/messages.rs

@@ -714,6 +714,11 @@ impl RuntimeApiRequest {
 
 	/// `Disputes`
 	pub const DISPUTES_RUNTIME_REQUIREMENT: u32 = 3;
+
+	/// Minimum version for valididty constraints, required for async backing.
+	///
+	/// 99 for now, should be adjusted to VSTAGING/actual runtime version once released.
+	pub const VALIDITY_CONSTRAINTS: u32 = 99;
 }
 
 /// A message to the Runtime API subsystem.