[PATCH i-g-t] tests/intel/intel_kernelfs: Unified testing for sysfs and debugfs

[Peter Senna Tschudin <peter.senna@linux.intel.com>]

The new test intel_kernelfs is designed to replace both debugfs_test and
xe_debugfs. intel_kernelfs:
 - Covers i915 and Xe
 - Test sysfs by trying to read all entries
 - Test debugs by trying to read all entries
 - Test Xe-specific debugfs files
 - Complete list of tests: intel-sysfs-read-all-entries,
   intel-debugfs-read-all-entries,
   intel-debugfs-read-all-entries-display-on,
   intel-debugfs-read-all-entries-display-off, xe-base, xe-gt,
   xe-forcewake

Cc: kamil.konieczny@linux.intel.com
Cc: katarzyna.piecielska@intel.com
Cc: rodrigo.vivi@intel.com
Signed-off-by: Peter Senna Tschudin <peter.senna@linux.intel.com>
---
 tests/intel/intel_kernelfs.c | 463 +++++++++++++++++++++++++++++++++++
 tests/meson.build            |   1 +
 2 files changed, 464 insertions(+)
 create mode 100644 tests/intel/intel_kernelfs.c

diff --git a/tests/intel/intel_kernelfs.c b/tests/intel/intel_kernelfs.c
new file mode 100644
index 000000000..6528838af
--- /dev/null
+++ b/tests/intel/intel_kernelfs.c
@@ -0,0 +1,463 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2025 Intel Corporation
+ */
+
+#include <dirent.h>
+#include <fcntl.h>
+
+#include "i915/gem.h"
+#include "igt.h"
+#include "igt_sysfs.h"
+#include "xe/xe_query.h"
+
+struct {
+	bool warn_on_not_hit;
+} opt = { 0 };
+
+/**
+ * TEST: debugfs test
+ * Description: Read entries from debugfs, and sysfs paths.
+ * Category: Core
+ * Mega feature: General Core features
+ * Sub-category: uapi
+ * Functionality: debugfs
+ * Feature: core
+ * Test category: uapi
+ *
+ * SUBTEST: intel-debugfs-read-all-entries
+ * Description: Read all entries from debugfs path validating debugfs entries
+ *
+ * SUBTEST: intel-debugfs-read-all-entries-display-off
+ * Description: Read all debugfs entries with display off.
+ *
+ * SUBTEST: intel-debugfs-read-all-entries-display-on
+ * Description: Read all debugfs entries with display on.
+ *
+ * SUBTEST: intel-sysfs-read-all-entries
+ * Description: Read all entries from sysfs path validating debugfs entries
+ *
+ */
+
+IGT_TEST_DESCRIPTION("Read entries from debugfs, and sysfs paths.");
+
+static void read_and_discard_sysfs_entries(int path_fd, int indent)
+{
+	struct dirent *dirent;
+	DIR *dir;
+	char tabs[8];
+	int i;
+
+	igt_assert(indent < sizeof(tabs) - 1);
+
+	for (i = 0; i < indent; i++)
+		tabs[i] = '\t';
+	tabs[i] = '\0';
+
+	dir = fdopendir(path_fd);
+	if (!dir)
+		return;
+
+	while ((dirent = readdir(dir))) {
+		if (!strcmp(dirent->d_name, ".") ||
+		    !strcmp(dirent->d_name, ".."))
+			continue;
+
+		if (dirent->d_type == DT_DIR) {
+			int sub_fd;
+
+			sub_fd = openat(path_fd, dirent->d_name,
+					O_RDONLY | O_DIRECTORY);
+			if (sub_fd < 0)
+				continue;
+
+			igt_debug("%sEntering subdir %s\n", tabs, dirent->d_name);
+			read_and_discard_sysfs_entries(sub_fd, indent + 1);
+			close(sub_fd);
+		} else if (dirent->d_type == DT_REG) {
+			char buf[512];
+			int sub_fd;
+			ssize_t ret;
+
+			igt_kmsg(KMSG_DEBUG "Reading file \"%s\"\n", dirent->d_name);
+			igt_debug("%sReading file \"%s\"\n", tabs, dirent->d_name);
+			igt_set_timeout(5, "reading sysfs entry");
+
+			sub_fd = openat(path_fd, dirent->d_name, O_RDONLY | O_NONBLOCK);
+			if (sub_fd == -1) {
+				igt_debug("%sCould not open file \"%s\" with error: %m\n",
+					  tabs, dirent->d_name);
+				continue;
+			}
+
+			do {
+				ret = read(sub_fd, buf, sizeof(buf));
+			} while (ret == sizeof(buf));
+
+			if (ret == -1)
+				igt_debug("%sCould not read file \"%s\" with error: %m\n",
+					  tabs, dirent->d_name);
+
+			igt_reset_timeout();
+			close(sub_fd);
+		}
+	}
+	closedir(dir);
+}
+
+static void kms_tests(int fd, int debugfs)
+{
+	igt_display_t display;
+	struct igt_fb fb[IGT_MAX_PIPES];
+	enum pipe pipe;
+	int ret;
+
+	igt_fixture
+		igt_display_require(&display, fd);
+
+	igt_subtest("intel-debugfs-read-all-entries-display-on") {
+		/* try to light all pipes */
+retry:
+		for_each_pipe(&display, pipe) {
+			igt_output_t *output;
+
+			for_each_valid_output_on_pipe(&display, pipe, output) {
+				igt_plane_t *primary;
+				drmModeModeInfo *mode;
+
+				if (output->pending_pipe != PIPE_NONE)
+					continue;
+
+				igt_output_set_pipe(output, pipe);
+				primary = igt_output_get_plane_type(output, DRM_PLANE_TYPE_PRIMARY);
+				mode = igt_output_get_mode(output);
+				igt_create_pattern_fb(display.drm_fd,
+						      mode->hdisplay, mode->vdisplay,
+						      DRM_FORMAT_XRGB8888,
+						      DRM_FORMAT_MOD_LINEAR, &fb[pipe]);
+
+				/* Set a valid fb as some debugfs like to
+				 * inspect it on a active pipe
+				 */
+				igt_plane_set_fb(primary, &fb[pipe]);
+				break;
+			}
+		}
+
+		if (display.is_atomic)
+			ret = igt_display_try_commit_atomic(&display,
+					DRM_MODE_ATOMIC_TEST_ONLY |
+					DRM_MODE_ATOMIC_ALLOW_MODESET,
+					NULL);
+		else
+			ret = igt_display_try_commit2(&display, COMMIT_LEGACY);
+
+		if (ret) {
+			igt_output_t *output;
+			bool found = igt_override_all_active_output_modes_to_fit_bw(&display);
+
+			igt_require_f(found, "No valid mode combo found.\n");
+
+			for_each_connected_output(&display, output)
+				igt_output_set_pipe(output, PIPE_NONE);
+
+			goto retry;
+		}
+
+		igt_display_commit2(&display, display.is_atomic ? COMMIT_ATOMIC : COMMIT_LEGACY);
+
+		read_and_discard_sysfs_entries(debugfs, 0);
+	}
+
+	igt_subtest("intel-debugfs-read-all-entries-display-off") {
+		igt_output_t *output;
+		igt_plane_t *plane;
+
+		for_each_connected_output(&display, output)
+			igt_output_set_pipe(output, PIPE_NONE);
+
+		for_each_pipe(&display, pipe)
+			for_each_plane_on_pipe(&display, pipe, plane)
+				igt_plane_set_fb(plane, NULL);
+
+		igt_display_commit2(&display, display.is_atomic ? COMMIT_ATOMIC : COMMIT_LEGACY);
+
+		read_and_discard_sysfs_entries(debugfs, 0);
+	}
+
+	igt_fixture
+		igt_display_fini(&display);
+}
+
+static int xe_validate_entries(int fd, const char *add_path,
+			       const char * const str_val[], int str_cnt)
+{
+	int i;
+	int hit;
+	int found = 0;
+	int not_found = 0;
+	DIR *dir;
+	struct dirent *de;
+	char path[PATH_MAX];
+
+	if (!igt_debugfs_path(fd, path, sizeof(path)))
+		return -1;
+
+	strcat(path, add_path);
+	dir = opendir(path);
+	if (!dir)
+		return -1;
+
+	while ((de = readdir(dir))) {
+		if (de->d_name[0] == '.')
+			continue;
+		hit = 0;
+		for (i = 0; i < str_cnt; i++) {
+			if (!strcmp(str_val[i], de->d_name)) {
+				hit = 1;
+				break;
+			}
+		}
+		if (hit) {
+			found++;
+		} else if (opt.warn_on_not_hit) {
+			not_found++;
+			igt_warn("no test for: %s/%s\n", path, de->d_name);
+		}
+	}
+	closedir(dir);
+	return 0;
+}
+
+/**
+ * SUBTEST: xe-base
+ * Description: Check if various debugfs devnodes exist and test reading them
+ */
+static void
+test_xe_base(int fd, struct drm_xe_query_config *config)
+{
+	uint16_t devid = intel_get_drm_devid(fd);
+	static const char * const expected_files[] = {
+		"gt0",
+		"gt1",
+		"stolen_mm",
+		"gtt_mm",
+		"vram0_mm",
+		"forcewake_all",
+		"info",
+		"gem_names",
+		"clients",
+		"name"
+	};
+	char reference[4096];
+	int val = 0;
+
+	igt_assert(config);
+	sprintf(reference, "devid 0x%llx",
+			config->info[DRM_XE_QUERY_CONFIG_REV_AND_DEVICE_ID] & 0xffff);
+	igt_assert(igt_debugfs_search(fd, "info", reference));
+
+	sprintf(reference, "revid %lld",
+			config->info[DRM_XE_QUERY_CONFIG_REV_AND_DEVICE_ID] >> 16);
+	igt_assert(igt_debugfs_search(fd, "info", reference));
+
+	sprintf(reference, "is_dgfx %s", config->info[DRM_XE_QUERY_CONFIG_FLAGS] &
+		DRM_XE_QUERY_CONFIG_FLAG_HAS_VRAM ? "yes" : "no");
+
+	igt_assert(igt_debugfs_search(fd, "info", reference));
+
+	if (intel_gen(devid) < 20) {
+		switch (config->info[DRM_XE_QUERY_CONFIG_VA_BITS]) {
+		case 48:
+			val = 3;
+			break;
+		case 57:
+			val = 4;
+			break;
+		}
+
+		sprintf(reference, "vm_max_level %d", val);
+		igt_assert(igt_debugfs_search(fd, "info", reference));
+	}
+
+	snprintf(reference, sizeof(reference), "tile_count %d", xe_sysfs_get_num_tiles(fd));
+	igt_assert(igt_debugfs_search(fd, "info", reference));
+
+	igt_assert(igt_debugfs_exists(fd, "gt0", O_RDONLY));
+
+	igt_assert(igt_debugfs_exists(fd, "gtt_mm", O_RDONLY));
+	igt_debugfs_dump(fd, "gtt_mm");
+
+	if (config->info[DRM_XE_QUERY_CONFIG_FLAGS] & DRM_XE_QUERY_CONFIG_FLAG_HAS_VRAM) {
+		igt_assert(igt_debugfs_exists(fd, "vram0_mm", O_RDONLY));
+		igt_debugfs_dump(fd, "vram0_mm");
+	}
+
+	if (igt_debugfs_exists(fd, "stolen_mm", O_RDONLY))
+		igt_debugfs_dump(fd, "stolen_mm");
+
+	igt_assert(igt_debugfs_exists(fd, "clients", O_RDONLY));
+	igt_debugfs_dump(fd, "clients");
+
+	igt_assert(igt_debugfs_exists(fd, "gem_names", O_RDONLY));
+	igt_debugfs_dump(fd, "gem_names");
+
+	xe_validate_entries(fd, "", expected_files, ARRAY_SIZE(expected_files));
+}
+
+/**
+ * SUBTEST: xe-gt
+ * Description: Check all gt debugfs devnodes
+ * TODO: add support for ``force_reset`` entries
+ */
+static void
+test_xe_gt(int fd, int gt_id)
+{
+	char name[256];
+	static const char * const expected_files[] = {
+		"uc",
+		"steering",
+		"topology",
+		"sa_info",
+		"hw_engines",
+		"pat",
+		"mocs",
+//		"force_reset"
+		"ggtt",
+		"register-save-restore",
+		"workarounds",
+		"default_lrc_rcs",
+		"default_lrc_ccs",
+		"default_lrc_bcs",
+		"default_lrc_vcs",
+		"default_lrc_vecs",
+		"hwconfig"
+
+	};
+	static const char * const expected_files_uc[] = {
+		"huc_info",
+		"guc_log",
+		"guc_info",
+//		"guc_ct_selftest"
+	};
+
+	for (int i = 0; i < ARRAY_SIZE(expected_files); i++) {
+		sprintf(name, "gt%d/%s", gt_id, expected_files[i]);
+		igt_assert(igt_debugfs_exists(fd, name, O_RDONLY));
+		if (igt_debugfs_is_dir(fd, expected_files[i], gt_id))
+			continue;
+		igt_debugfs_dump(fd, name);
+	}
+
+	for (int i = 0; i < ARRAY_SIZE(expected_files_uc); i++) {
+		sprintf(name, "gt%d/uc/%s", gt_id, expected_files_uc[i]);
+		igt_assert(igt_debugfs_exists(fd, name, O_RDONLY));
+		igt_debugfs_dump(fd, name);
+	}
+
+	sprintf(name, "/gt%d", gt_id);
+	xe_validate_entries(fd, name, expected_files, ARRAY_SIZE(expected_files));
+
+	sprintf(name, "/gt%d/uc", gt_id);
+	xe_validate_entries(fd, name, expected_files_uc, ARRAY_SIZE(expected_files_uc));
+}
+
+/**
+ * SUBTEST: xe-forcewake
+ * Description: Check forcewake debugfs devnode
+ */
+static void
+test_xe_forcewake(int fd)
+{
+	int handle = igt_debugfs_open(fd, "forcewake_all", O_WRONLY);
+
+	igt_assert_neq(handle, -1);
+	close(handle);
+}
+
+const char *help_str =
+	"  -w\t--warn-not-hit Produce warnings if it founds a devfs node without tests";
+
+struct option long_options[] = {
+	{ "--warn-not-hit", no_argument, NULL, 'w'},
+	{ 0, 0, 0, 0 }
+};
+
+static int opt_handler(int option, int option_index, void *input)
+{
+	switch (option) {
+	case 'w':
+		opt.warn_on_not_hit = true;
+		break;
+	default:
+		return IGT_OPT_HANDLER_ERROR;
+	}
+
+	return IGT_OPT_HANDLER_SUCCESS;
+}
+
+igt_main_args("", long_options, help_str, opt_handler, NULL)
+{
+	int debugfs;
+	char devnode[PATH_MAX];
+	int fd = -1;
+	int gt;
+	enum intel_driver driver;
+	int sysfs;
+
+	igt_fixture {
+		fd = drm_open_driver_master(DRIVER_INTEL | DRIVER_XE);
+		driver = get_intel_driver(fd);
+
+		debugfs = igt_debugfs_dir(fd);
+		sysfs = igt_sysfs_open(fd);
+
+		kmstest_set_vt_graphics_mode();
+
+		if (driver == INTEL_DRIVER_I915)
+			igt_require_gem(fd);
+		else if (driver == INTEL_DRIVER_XE)
+			__igt_debugfs_dump(fd, "info", IGT_LOG_INFO);
+	}
+
+	igt_describe("Read all entries from sysfs path.");
+	igt_subtest("intel-sysfs-read-all-entries")
+		read_and_discard_sysfs_entries(sysfs, 0);
+	igt_describe("Read all entries from debugfs path.");
+	igt_subtest("intel-debugfs-read-all-entries")
+		read_and_discard_sysfs_entries(debugfs, 0);
+
+	igt_describe("Read all debugfs entries with display on/off.");
+	igt_subtest_group
+		kms_tests(fd, debugfs);
+
+	igt_fixture
+		igt_skip_on_f(driver != INTEL_DRIVER_XE, "No Xe card found.\n");
+
+	igt_subtest_group {
+		igt_describe("Check if various debugfs devnodes exist and test reading them.");
+		igt_subtest("xe-base") {
+			test_xe_base(fd, xe_config(fd));
+		}
+
+		igt_describe("Check all gt debugfs devnodes");
+		igt_subtest("xe-gt") {
+			xe_for_each_gt(fd, gt) {
+				snprintf(devnode, sizeof(devnode), "gt%d", gt);
+				igt_require(igt_debugfs_exists(fd, devnode, O_RDONLY));
+				test_xe_gt(fd, gt);
+			}
+		}
+
+		igt_describe("Check forcewake debugfs devnode");
+		igt_subtest("xe-forcewake") {
+			test_xe_forcewake(fd);
+		}
+	}
+
+	igt_fixture {
+		close(sysfs);
+		close(debugfs);
+		drm_close_driver(fd);
+	}
+}
diff --git a/tests/meson.build b/tests/meson.build
index 2f5406523..c98bd45ff 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -83,6 +83,7 @@ test_progs = [
 intel_i915_xe_progs = [
 	'api_intel_allocator',
 	'intel_hwmon',
+	'intel_kernelfs',
 ]
 
 intel_i915_progs = [
-- 
2.34.1