[MRV2] Fix for DS v3.2

[WoosukKwon]

No description provided.

[gemini-code-assist]

Code Review

This pull request modifies the _reshape_kv_cache function to accommodate more flexible KV cache specifications, allowing for both uniform and layer-specific AttentionSpec configurations. A review comment highlights a potential issue where the assert statement used for type checking kv_cache_spec could be bypassed in production if assertions are disabled, suggesting a more robust type validation using an explicit TypeError or ValueError to ensure consistent error handling.

[gemini-code-assist]

The assert statement on this line performs a critical type check. If assertions are disabled in a production environment, this check will be skipped, potentially leading to AttributeError or TypeError in subsequent operations if kv_cache_spec is not an AttentionSpec. For robust error handling, consider replacing this assert with an explicit TypeError or ValueError to ensure type validation always occurs, regardless of assertion settings.

Suggested change

	assert isinstance(kv_cache_spec, AttentionSpec)
	if not isinstance(kv_cache_spec, AttentionSpec):
	raise TypeError(f"Expected kv_cache_spec to be AttentionSpec, but got {type(kv_cache_spec)}")