[Bugfix] Restore support for larger block sizes (#11259)

Signed-off-by: Konrad Zawora <kzawora@habana.ai>

vllm/config.py

@@ -917,6 +917,10 @@ class CacheConfig:
             raise ValueError(
                 "GPU memory utilization must be less than 1.0. Got "
                 f"{self.gpu_memory_utilization}.")
+        if (current_platform.is_cuda() and self.block_size is not None
+                and self.block_size > 32):
+            raise ValueError("CUDA Paged Attention kernel only supports "
+                             f"block sizes up to 32. Got {self.block_size}.")
 
     def _verify_cache_dtype(self) -> None:
         if self.cache_dtype == "auto":

vllm/engine/arg_utils.py

@@ -424,10 +424,12 @@ class EngineArgs:
         parser.add_argument('--block-size',
                             type=int,
                             default=EngineArgs.block_size,
-                            choices=[8, 16, 32],
+                            choices=[8, 16, 32, 64, 128],
                             help='Token block size for contiguous chunks of '
                             'tokens. This is ignored on neuron devices and '
-                            'set to max-model-len')
+                            'set to max-model-len. On CUDA devices, '
+                            'only block sizes up to 32 are supported. '
+                            'On HPU devices, block size defaults to 128.')
 
         parser.add_argument(
             "--enable-prefix-caching",