[ROCm] Disable chunked prefill/prefix caching when running MLA on non-cuda platforms (#13844)

Signed-off-by: Sage Moore <sage@neuralmagic.com>

vllm/config.py

@@ -3422,6 +3422,20 @@ class VllmConfig:
                            "Disabling `torch.compile`.")
             self.compilation_config.level = CompilationLevel.NO_COMPILATION
 
+        if self.model_config and self.model_config.use_mla and \
+            not current_platform.is_cuda():
+            logger.info(
+                "MLA is enabled on a non-cuda platform; forcing chunked "
+                "prefill and prefix caching to be disabled.")
+            self.scheduler_config.enable_chunked_prefill = False
+            self.scheduler_config.chunked_prefill_enabled = False
+            self.scheduler_config.max_num_batched_tokens = max(
+                self.scheduler_config.max_model_len,
+                _DEFAULT_MAX_NUM_BATCHED_TOKENS)
+
+            if self.cache_config is not None:
+                self.cache_config.enable_prefix_caching = False
+
         current_platform.check_and_update_config(self)
 
         if not self.instance_id: