ANDROID: Add kunit targets.

The kunit targets build in-tree kunit modules with a pre-set
defconfig fragment.

This is the defconfig fragment to be applied to enable kunit tests
as modules. Because we apply defconfig fragments after running
make defconfig, the individual tests must be enabled instead of
a global CONFIG_KUNIT_ALL_TESTS flag.

Test: manually build with
  bazel run //common:kunit_aarch64_dist
  bazel run //common:kunit_x86_64_dist
  bazel run //common:kunit_riscv64_dist
Bug: 296116800
Change-Id: If3b94f495aa64b657508781b12e3e0716c725f3f
Signed-off-by: Yifan Hong <elsk@google.com>

BUILD.bazel

@@ -553,6 +553,100 @@ kernel_build(
     visibility = ["//visibility:private"],
 )
 
+# KUnit test targets
+
+# Modules defined by tools/testing/kunit/configs/android/kunit_defconfig
+_KUNIT_COMMON_MODULES = [
+    # keep sorted
+    "drivers/base/regmap/regmap-kunit.ko",
+    "drivers/base/regmap/regmap-ram.ko",
+    "drivers/base/regmap/regmap-raw-ram.ko",
+    "drivers/hid/hid-uclogic-test.ko",
+    "drivers/iio/test/iio-test-format.ko",
+    "drivers/input/tests/input_test.ko",
+    "drivers/rtc/lib_test.ko",
+    "fs/ext4/ext4-inode-test.ko",
+    "fs/fat/fat_test.ko",
+    "kernel/time/time_test.ko",
+    "lib/kunit/kunit-example-test.ko",
+    "lib/kunit/kunit-test.ko",
+    "mm/kfence/kfence_test.ko",
+    "net/core/dev_addr_lists_test.ko",
+    "sound/soc/soc-topology-test.ko",
+    "sound/soc/soc-utils-test.ko",
+]
+
+_KUNIT_CLK_MODULES = [
+    "drivers/clk/clk-gate_test.ko",
+    "drivers/clk/clk_test.ko",
+]
+
+kernel_build(
+    name = "kunit_aarch64",
+    outs = [],
+    arch = "arm64",
+    base_kernel = ":kernel_aarch64",
+    build_config = "build.config.kunit.aarch64",
+    defconfig_fragments = [
+        "tools/testing/kunit/configs/android/kunit_defconfig",
+        "tools/testing/kunit/configs/android/kunit_clk_defconfig",
+    ],
+    make_goals = ["modules"],
+    module_outs = _KUNIT_COMMON_MODULES + _KUNIT_CLK_MODULES,
+)
+
+copy_to_dist_dir(
+    name = "kunit_aarch64_dist",
+    data = [":kunit_aarch64"],
+    dist_dir = "out/kunit_aarch64/dist",
+    flat = True,
+    log = "info",
+)
+
+kernel_build(
+    name = "kunit_x86_64",
+    outs = [],
+    arch = "x86_64",
+    base_kernel = ":kernel_x86_64",
+    build_config = "build.config.kunit.x86_64",
+    defconfig_fragments = [
+        "tools/testing/kunit/configs/android/kunit_defconfig",
+        # x86_64 does not set CONFIG_COMMON_CLK
+    ],
+    make_goals = ["modules"],
+    module_outs = _KUNIT_COMMON_MODULES,
+)
+
+copy_to_dist_dir(
+    name = "kunit_x86_64_dist",
+    data = [":kunit_x86_64"],
+    dist_dir = "out/kunit_x86_64/dist",
+    flat = True,
+    log = "info",
+)
+
+kernel_build(
+    name = "kunit_riscv64",
+    outs = [],
+    arch = "riscv64",
+    base_kernel = ":kernel_riscv64",
+    build_config = "build.config.kunit.riscv64",
+    defconfig_fragments = [
+        "tools/testing/kunit/configs/android/kunit_defconfig",
+        "tools/testing/kunit/configs/android/kunit_clk_defconfig",
+    ],
+    make_goals = ["modules"],
+    module_outs = _KUNIT_COMMON_MODULES + _KUNIT_CLK_MODULES,
+)
+
+copy_to_dist_dir(
+    name = "kunit_riscv64_dist",
+    data = [":kunit_riscv64"],
+    dist_dir = "out/kunit_riscv64/dist",
+    flat = True,
+    log = "info",
+)
+
 # DDK Headers
 # All headers. These are the public targets for DDK modules to use.
 alias(

build.config.kunit.aarch64

@@ -0,0 +1,4 @@
+. ${ROOT_DIR}/${KERNEL_DIR}/build.config.common
+. ${ROOT_DIR}/${KERNEL_DIR}/build.config.aarch64
+
+DEFCONFIG=gki_defconfig

build.config.kunit.riscv64

@@ -0,0 +1,4 @@
+. ${ROOT_DIR}/${KERNEL_DIR}/build.config.common
+. ${ROOT_DIR}/${KERNEL_DIR}/build.config.riscv64
+
+DEFCONFIG=gki_defconfig

build.config.kunit.x86_64

@@ -0,0 +1,4 @@
+. ${ROOT_DIR}/${KERNEL_DIR}/build.config.common
+. ${ROOT_DIR}/${KERNEL_DIR}/build.config.x86_64
+
+DEFCONFIG=gki_defconfig

tools/testing/kunit/configs/android/kunit_clk_defconfig

@@ -0,0 +1,3 @@
+# Only for architectures that set CONFIG_COMMON_CLK
+CONFIG_CLK_KUNIT_TEST=m
+CONFIG_CLK_GATE_KUNIT_TEST=m

tools/testing/kunit/configs/android/kunit_defconfig

@@ -0,0 +1,37 @@
+# Defconfig fragment for Android Kunit targets
+#
+# Instead of setting CONFIG_KUNIT_ALL_TESTS=m, we enable individual tests
+# because:
+# - The defconfig fragment is applied after make defconfig
+# - If additional tests are added to CONFIG_KUNIT_ALL_TESTS in the future,
+#   //common:kunit_* module_outs needs to be updated.
+
+# CONFIG_MODULE_SIG_ALL is not set
+
+# Corresponds to BUILD.bazel, _KUNIT_COMMON_MODULES
+CONFIG_TIME_KUNIT_TEST=m
+CONFIG_NETDEV_ADDR_LIST_TEST=m
+CONFIG_REGMAP_KUNIT=m
+CONFIG_INPUT_KUNIT_TEST=m
+CONFIG_SND_SOC_TOPOLOGY_KUNIT_TEST=m
+CONFIG_SND_SOC_UTILS_KUNIT_TEST=m
+CONFIG_HID_KUNIT_TEST=m
+CONFIG_RTC_LIB_KUNIT_TEST=m
+CONFIG_IIO_FORMAT_KUNIT_TEST=m
+CONFIG_EXT4_KUNIT_TESTS=m
+CONFIG_FAT_KUNIT_TEST=m
+CONFIG_KFENCE_KUNIT_TEST=m
+CONFIG_KUNIT_TEST=m
+CONFIG_KUNIT_EXAMPLE_TEST=m
+
+# CONFIG_NET_HANDSHAKE is not enabled in gki_defconfig.
+# CONFIG_NET_HANDSHAKE_KUNIT_TEST=m
+
+# TODO(b/296116800): Enable these tests
+# CONFIG_DRM_KUNIT_TEST=m
+# CONFIG_KASAN_KUNIT_TEST=m
+
+# TODO(b/296116800): These are booleans, not tristates.
+# CONFIG_BINFMT_ELF_KUNIT_TEST=y
+# CONFIG_PM_QOS_KUNIT_TEST=y
+# CONFIG_DRIVER_PE_KUNIT_TEST=y