[ROCm][CI][Bugfix] Disable Flash/MemEfficient SDP on ROCm to avoid HF Transformers accuracy issues (#29909)

Signed-off-by: Andreas Karatzas <akaratza@amd.com>

tests/models/multimodal/generation/conftest.py

@@ -0,0 +1,19 @@
+# SPDX-License-Identifier: Apache-2.0
+# SPDX-FileCopyrightText: Copyright contributors to the vLLM project
+"""Pytest configuration for vLLM tests."""
+
+import torch
+
+from vllm.platforms import current_platform
+
+
+def pytest_configure(config):
+    """Disable Flash/MemEfficient SDP on ROCm to avoid HF
+    Transformers accuracy issues.
+    """
+    if not current_platform.is_rocm():
+        return
+
+    torch.backends.cuda.enable_flash_sdp(False)
+    torch.backends.cuda.enable_mem_efficient_sdp(False)
+    torch.backends.cuda.enable_math_sdp(True)