[ROCm] Apply FP8 weights padding to values not divisible by 512 bytes on ROCm (#13231)

vllm/envs.py

@@ -74,6 +74,7 @@ if TYPE_CHECKING:
     VLLM_SKIP_P2P_CHECK: bool = False
     VLLM_DISABLED_KERNELS: List[str] = []
     VLLM_USE_V1: bool = False
+    VLLM_ROCM_FP8_PADDING: bool = True
     VLLM_ENABLE_V1_MULTIPROCESSING: bool = True
     VLLM_LOG_BATCHSIZE_INTERVAL: float = -1
     VLLM_DISABLE_COMPILE_CACHE: bool = False
@@ -507,6 +508,9 @@ environment_variables: Dict[str, Callable[[], Any]] = {
     "VLLM_USE_V1":
     lambda: bool(int(os.getenv("VLLM_USE_V1", "0"))),
 
+    # Pad the fp8 weights to 256 bytes for ROCm
+    "VLLM_ROCM_FP8_PADDING":
+    lambda: bool(int(os.getenv("VLLM_ROCM_FP8_PADDING", "1"))),
     # Divisor for dynamic key scale factor calculation for FP8 KV Cache
     "K_SCALE_CONSTANT":
     lambda: int(os.getenv("K_SCALE_CONSTANT", "200")),