[UnitTest] Disable ptx mma tests on unsupported nvcc versions.

- Modified `tvm.contrib.nvcc.get_cuda_version` to return a
  `(major,minor,release)` tuple rather than a float.

- Implemented `tvm.testing.requries_nvcc_version` decorator to specify
  the minimum `(major,minor,release)` version needed to run a unit
  test.

- Applied decorated to unit tests in `test_tir_ptx_mma.py` that fail
  on earlier nvcc versions.

python/tvm/contrib/cutlass/build.py

@@ -61,9 +61,8 @@ def _get_cutlass_compile_options(sm, threads, use_fast_math=False):
     ]
     if use_fast_math:
         kwargs["options"].append("-DCUTLASS_USE_TANH_FOR_SIGMOID")
-    cuda_path = find_cuda_path()
-    cuda_ver = get_cuda_version(cuda_path)
-    if cuda_ver >= 11.2:
+    cuda_ver = get_cuda_version()
+    if cuda_ver >= (11, 2):
         ncpu = multiprocessing.cpu_count() if threads < 0 else threads
         kwargs["options"].append("-t %d" % ncpu)
     return kwargs

python/tvm/contrib/nvcc.py

@@ -140,27 +140,33 @@ def find_cuda_path():
     raise RuntimeError("Cannot find cuda path")
 
 
-def get_cuda_version(cuda_path):
+def get_cuda_version(cuda_path=None):
     """Utility function to get cuda version
 
     Parameters
     ----------
-    cuda_path : str
-        Path to cuda root.
+    cuda_path : Optional[str]
+
+        Path to cuda root.  If None is passed, will use
+        `find_cuda_path()` as default.
 
     Returns
     -------
     version : float
         The cuda version
+
     """
+    if cuda_path is None:
+        cuda_path = find_cuda_path()
+
     version_file_path = os.path.join(cuda_path, "version.txt")
     if not os.path.exists(version_file_path):
         # Debian/Ubuntu repackaged CUDA path
         version_file_path = os.path.join(cuda_path, "lib", "cuda", "version.txt")
     try:
         with open(version_file_path) as f:
-            version_str = f.readline().replace("\n", "").replace("\r", "")
-            return float(version_str.split(" ")[2][:2])
+            version_str = f.read().strip().split()[-1]
+            return tuple(int(field) for field in version_str.split("."))
     except FileNotFoundError:
         pass
 
@@ -171,9 +177,8 @@ def get_cuda_version(cuda_path):
     if proc.returncode == 0:
         release_line = [l for l in out.split("\n") if "release" in l][0]
         release_fields = [s.strip() for s in release_line.split(",")]
-        release_version = [f[1:] for f in release_fields if f.startswith("V")][0]
-        major_minor = ".".join(release_version.split(".")[:2])
-        return float(major_minor)
+        version_str = [f[1:] for f in release_fields if f.startswith("V")][0]
+        return tuple(int(field) for field in version_str.split("."))
     raise RuntimeError("Cannot read cuda version file")
 
 

python/tvm/testing/utils.py

@@ -635,6 +635,49 @@ def requires_nvptx(*args):
     return _compose(args, _requires_nvptx)
 
 
+def requires_nvcc_version(major_version, minor_version=0, release_version=0):
+    """Mark a test as requiring at least a specific version of nvcc.
+
+    Unit test marked with this decorator will run only if the
+    installed version of NVCC is at least `(major_version,
+    minor_version, release_version)`.
+
+    This also marks the test as requiring a cuda support.
+
+    Parameters
+    ----------
+    major_version: int
+
+        The major version of the (major,minor,release) version tuple.
+
+    minor_version: int
+
+        The minor version of the (major,minor,release) version tuple.
+
+    release_version: int
+
+        The release version of the (major,minor,release) version tuple.
+
+    """
+
+    try:
+        nvcc_version = nvcc.get_cuda_version()
+    except RuntimeError:
+        nvcc_version = (0, 0, 0)
+
+    min_version = (major_version, minor_version, release_version)
+    version_str = ".".join(str(v) for v in min_version)
+    requires = [
+        pytest.mark.skipif(nvcc_version < min_version, reason=f"Requires NVCC >= {version_str}"),
+        *requires_cuda(),
+    ]
+
+    def inner(func):
+        return _compose([inner], requires)
+
+    return inner
+
+
 def requires_cudagraph(*args):
     """Mark a test as requiring the CUDA Graph Feature
 

tests/python/unittest/test_tir_ptx_mma.py

@@ -310,6 +310,10 @@ def gemm_mma_m8n8k16_row_col_s8s8s32(a: T.handle, b: T.handle, c: T.handle):
         )
 
 
+# This test uses mma instructions that are not available on NVCC 10.1.
+# Failure occurs during the external call to nvcc, when attempting to
+# generate the .fatbin file.
+@tvm.testing.requires_nvcc_version(11)
 @tvm.testing.requires_cuda
 def test_gemm_mma_m8n8k16_row_col_s8s8s32():
     sch = tvm.tir.Schedule(gemm_mma_m8n8k16_row_col_s8s8s32)
@@ -384,6 +388,10 @@ def gemm_mma_m8n8k16_row_col_s8u8s32(a: T.handle, b: T.handle, c: T.handle):
         )
 
 
+# This test uses mma instructions that are not available on NVCC 10.1.
+# Failure occurs during the external call to nvcc, when attempting to
+# generate the .fatbin file.
+@tvm.testing.requires_nvcc_version(11)
 @tvm.testing.requires_cuda
 def test_gemm_mma_m8n8k16_row_col_s8u8s32():
     sch = tvm.tir.Schedule(gemm_mma_m8n8k16_row_col_s8u8s32)
@@ -458,6 +466,10 @@ def gemm_mma_m8n8k32_row_col_s4s4s32(a: T.handle, b: T.handle, c: T.handle):
         )
 
 
+# This test uses mma instructions that are not available on NVCC 10.1.
+# Failure occurs during the external call to nvcc, when attempting to
+# generate the .fatbin file.
+@tvm.testing.requires_nvcc_version(11)
 @tvm.testing.requires_cuda
 def test_gemm_mma_m8n8k32_row_col_s4s4s32():
     sch = tvm.tir.Schedule(gemm_mma_m8n8k32_row_col_s4s4s32)
@@ -524,6 +536,10 @@ def gemm_mma_m8n8k32_row_col_s4u4s32(a: T.handle, b: T.handle, c: T.handle):
         )
 
 
+# This test uses mma instructions that are not available on NVCC 10.1.
+# Failure occurs during the external call to nvcc, when attempting to
+# generate the .fatbin file.
+@tvm.testing.requires_nvcc_version(11)
 @tvm.testing.requires_cuda
 def test_gemm_mma_m8n8k32_row_col_s4u4s32():
     sch = tvm.tir.Schedule(gemm_mma_m8n8k32_row_col_s4u4s32)