Re: [PATCH i-g-t v2 1/2] test/intel/xe_pmt: Add testing for BMG PMT features

[Rodrigo Vivi <rodrigo.vivi@intel.com>]

On Wed, Oct 28, 2026 at 01:05:01PM -0700, Michael J. Ruhl wrote:
> Battlemage (BMG) devices have the Platform Monitoring
> Technology (PMT) telemetry and crashlog features. If the
> device present is a BMG, test the PMT API.
> 
> NOTE: the testing order is not flexible and must be done in
> the currently specified order.
> 
> Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
> ---
>  tests/intel/xe_pmt.c | 562 +++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 562 insertions(+)
>  create mode 100644 tests/intel/xe_pmt.c
> 
> diff --git a/tests/intel/xe_pmt.c b/tests/intel/xe_pmt.c
> new file mode 100644
> index 000000000..af5d470b5
> --- /dev/null
> +++ b/tests/intel/xe_pmt.c
> @@ -0,0 +1,562 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright © 2025 Intel Corporation
> + */
> +
> +#include <unistd.h>
> +#include <dirent.h>
> +#include <fcntl.h>
> +#include <limits.h>
> +#include <string.h>
> +
> +#include "igt.h"
> +#include "igt_sysfs.h"
> +#include "linux_scaffold.h"
> +#include "xe_drm.h"
> +#include "xe/xe_ioctl.h"
> +#include "xe/xe_query.h"
> +
> +/**
> + * TEST: Verify Platform Monitoring Technology (PMT) files operations
> + * Category: Core
> + * Mega feature: General Core features
> + * Sub-category: uapi
> + * Functionality: sysfs
> + * Description: Verify that the available PMT files (crashlog and telemetry)
> + *   are created, are accessable, and respond as per design.
> + *
> + * SUBTEST: pmt-bmg-all
> + * Description:
> + *   Exercise the BMG PMT feature
> + *
> + */
> +
> +IGT_TEST_DESCRIPTION("Verify Platform Monitoring Technology (PMT) files operations");
> +
> +/* base directory names */
> +#define VSEC_CRASHLOG_DIR "intel_vsec.crashlog."
> +#define VSEC_TELEMETRY_DIR "intel_vsec.telemetry."
> +#define CRASHLOG_DIR "crashlog"
> +#define TELEMETRY_DIR "telem"
> +
> +/* itemize the available instances for the specific device */
> +enum bmg_crashlog_instances {
> +	bmg_crashlog_punit = 0,
> +	bmg_crashlog_oobmsm,
> +	bmg_crashlog_max
> +};
> +
> +enum bmg_telemety_instances {
> +	bmg_telemetry_punit = 0,
> +	bmg_telemetry_oobmsm,
> +	bmg_telemetry_max
> +};
> +
> +static char dev_path[PATH_MAX];
> +static char work_path[PATH_MAX * 2];
> +
> +/*
> + * In most case there should be a single instance of the crashlog and telemetry
> + * directories. If DVSEC entries are not contiguous the structure will be different,
> + * and the code will need to reflect the structure.
> + */
> +static char crashlog_vsec_dir[32];
> +static char telemetry_vsec_dir[32];
> +
> +/* This needs to be specific for each supported device */
> +static char crashlog_dir[bmg_crashlog_max][32];
> +static char telemetry_dir[bmg_telemetry_max][32];
> +
> +/* telemetry file names */
> +static const char *telem = "telem";
> +
> +/* crashlog filenames and descriptors */
> +static const char *clear = "clear";
> +static const char *consumed = "consumed";
> +static const char *crashlog = "crashlog";
> +static const char *enable = "enable";
> +static const char *error = "error";
> +static const char *dev_guid = "guid";
> +static const char *rearm = "rearm";
> +static const char *trigger = "trigger";
> +
> +struct crashlog_v2_info {
> +	int clear_fd;
> +	int consumed_fd;
> +	int crashlog_fd;
> +	int enable_fd;
> +	int error_fd;
> +	int guid_fd;
> +	int rearm_fd;
> +	int trigger_fd;
> +	u_int32_t guid;
> +} bmg_info[bmg_crashlog_max];
> +
> +#define DEV_PATH_LEN 80
> +
> +/*
> + * device_sysfs_path:
> + * @fd: opened device file descriptor
> + * @path: buffer to store sysfs path to device directory
> + *
> + * Returns:
> + * On successfull path resolution sysfs path to device directory,
> + * NULL otherwise
> + */
> +static char *device_sysfs_path(int fd, char *path)
> +{
> +        char sysfs[DEV_PATH_LEN];
> +
> +        if (!igt_sysfs_path(fd, sysfs, sizeof(sysfs)))
> +                return NULL;
> +
> +        if (DEV_PATH_LEN <= (strlen(sysfs) + strlen("/device")))
> +                return NULL;
> +
> +        strcat(sysfs, "/device");
> +
> +        return realpath(sysfs, path);
> +}
> +
> +/*
> + * Verify the PMT directory structure
> + *
> + * BMG PMT directory structure:
> + *   device/intel_vsec.crashlog.x/intel_pmt/crashlog<a,b>
> + *   device/intel_vsec.telemetry.x/intel_pmt/telemetry<c,d>
> + *
> + * Note: different platforms could have a different pattern
> + */
> +static void test_pmt_directories(int dev_fd)
> +{
> +	struct dirent *ent;
> +	int index;
> +	DIR *dir;
> +
> +	igt_assert(device_sysfs_path(dev_fd, dev_path));
> +
> +	/* verify top level PMT directories */
> +	dir = opendir(dev_path);
> +	igt_assert_f(dir, "no directories found\n");
> +
> +	while ((ent = readdir(dir)) != NULL) {
> +		if (strncmp(VSEC_CRASHLOG_DIR, ent->d_name, sizeof(VSEC_CRASHLOG_DIR) - 1) == 0)
> +			strcpy(crashlog_vsec_dir, ent->d_name);
> +		if (strncmp(VSEC_TELEMETRY_DIR, ent->d_name, sizeof(VSEC_TELEMETRY_DIR) - 1) == 0)
> +			strcpy(telemetry_vsec_dir, ent->d_name);
> +	}
> +
> +	closedir(dir);
> +
> +	igt_assert_f(strlen(crashlog_vsec_dir), "missing crashlog directory\n");
> +	igt_assert_f(strlen(telemetry_vsec_dir), "missing telemetry directory\n");
> +
> +	/* verify crashlog directory structure */
> +	sprintf(work_path, "%s/%s/%s", dev_path, crashlog_vsec_dir, "intel_pmt");
> +
> +	dir = opendir(work_path);
> +	igt_assert_f(dir, "no intel_pmt directories found\n");
> +
> +	index = 0;
> +	/* find the crashlog<x> directory instances */
> +	while ((ent = readdir(dir)) != NULL) {
> +		if (strncmp(CRASHLOG_DIR, ent->d_name, sizeof(CRASHLOG_DIR) - 1) == 0) {
> +			if (index < bmg_crashlog_max)
> +				strcpy(crashlog_dir[index], ent->d_name);
> +			index++;
> +		}
> +	}
> +
> +	closedir(dir);
> +
> +	igt_assert_f(index == bmg_crashlog_max, "too many crashlog entries %d\n", index);
> +	for (int i = 0; i < ARRAY_SIZE(crashlog_dir); i++)
> +		igt_assert_f(strlen(crashlog_dir[i]), "missing crashlog[%d] directory\n", i);
> +
> +	/* verify telemetry directory structure */
> +	sprintf(work_path, "%s/%s/%s", dev_path, telemetry_vsec_dir, "intel_pmt");
> +
> +	dir = opendir(work_path);
> +	igt_assert_f(dir, "no telemetry intel_pmt directories found\n");
> +
> +	index = 0;
> +	while ((ent = readdir(dir)) != NULL) {
> +		if (strncmp(TELEMETRY_DIR, ent->d_name, sizeof(TELEMETRY_DIR) - 1) == 0) {
> +			if (index < bmg_telemetry_max)
> +				strcpy(telemetry_dir[index], ent->d_name);
> +			index++;
> +		}
> +	}
> +
> +	closedir(dir);
> +
> +	igt_assert_f(index == bmg_telemetry_max, "too many telemetry entries %d\n", index);
> +	for (int i = 0; i < ARRAY_SIZE(telemetry_dir); i++)
> +		igt_assert_f(strlen(telemetry_dir[i]), "missing telemetry[%d] directory\n", i);
> +
> +}
> +
> +static void find_pmt_file(const char *path, const char *file)
> +{
> +	struct dirent *ent;
> +	bool found;
> +	DIR *dir;
> +
> +	dir = opendir(path);
> +	igt_assert_f(dir, "no intel_pmt directories found\n");
> +
> +	found = false;
> +	while ((ent = readdir(dir)) != NULL)
> +		if (strcmp(file, ent->d_name) == 0)
> +			found = true;
> +	closedir(dir);
> +
> +	igt_assert_f(found, "missing %s from %s\n", file, path);
> +}
> +
> +static void open_pmt_file(const char *path, const char *file, int *fd, int flags)
> +{
> +	char file_path[PATH_MAX * 2 + 1];
> +
> +	sprintf(file_path, "%s/%s", path, file);
> +
> +	*fd = open(file_path, flags);
> +	igt_assert_f(*fd > -1, "failed to open %s\n", file_path);
> +}
> +
> +/*
> + * verify that the expected telemetry file(s) are in place
> + */
> +static void test_pmt_telemetry_files(int dev_fd)
> +{
> +	int i;
> +
> +	for (i = 0; i < bmg_telemetry_max; i++) {
> +		sprintf(work_path, "%s/%s/%s/%s", dev_path, telemetry_vsec_dir,
> +			"intel_pmt", telemetry_dir[i]);
> +		find_pmt_file(work_path, telem);
> +	}
> +}
> +
> +/*
> + * verify that a read will be successful
> + */
> +static void test_pmt_telemetry_read_data(int dev_fd)
> +{
> +	char buf[64] = {};
> +	u_int32_t *val;
> +	u_int32_t guid;
> +	int telem_fd;
> +	int guid_fd;
> +	int ret;
> +	int len;
> +	int i;
> +
> +	for (i = 0; i < bmg_telemetry_max; i++) {
> +		sprintf(work_path, "%s/%s/%s/%s", dev_path, telemetry_vsec_dir,
> +			"intel_pmt", telemetry_dir[i]);
> +		open_pmt_file(work_path, telem, &telem_fd, O_RDONLY);
> +		open_pmt_file(work_path, dev_guid, &guid_fd, O_RDONLY);
> +
> +		ret = pread(guid_fd, buf, sizeof(buf), 0);
> +		igt_assert_f(ret > 0, "failed to read guid for device %d\n", i);
> +		guid = strtol(buf, NULL, 16);
> +		igt_assert_f(guid > 0, "failed to get guid for device %d\n", i);
> +
> +		len = read(telem_fd, buf, sizeof(buf));
> +		igt_assert_f(len == sizeof(buf), "0x%x: failed to read telemetry data\n", guid);
> +
> +		val = (u_int32_t *)buf;
> +		igt_assert_f(*val != 0xffffffff, "0x%x: invalid telemetry data value: : 0x%x\n",
> +			     guid, *val);
> +
> +		close(telem_fd);
> +		close(guid_fd);
> +	}
> +}
> +
> +/*
> + * verify that the expected crashlog files are in place
> + */
> +static void test_pmt_crashlog_files(int dev_fd)
> +{
> +	char buf[64] = {};
> +	int ret;
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(bmg_info); i++) {
> +		sprintf(work_path, "%s/%s/%s/%s", dev_path, crashlog_vsec_dir, "intel_pmt",
> +			crashlog_dir[i]);
> +
> +		open_pmt_file(work_path, clear, &bmg_info[i].clear_fd, O_RDONLY);
> +		open_pmt_file(work_path, consumed, &bmg_info[i].consumed_fd, O_RDWR);
> +		open_pmt_file(work_path, crashlog, &bmg_info[i].crashlog_fd, O_RDONLY);
> +		open_pmt_file(work_path, enable, &bmg_info[i].enable_fd, O_RDWR);
> +		open_pmt_file(work_path, error, &bmg_info[i].error_fd, O_RDONLY);
> +		open_pmt_file(work_path, dev_guid, &bmg_info[i].guid_fd, O_RDONLY);
> +		open_pmt_file(work_path, rearm, &bmg_info[i].rearm_fd, O_RDWR);
> +		open_pmt_file(work_path, trigger, &bmg_info[i].trigger_fd, O_RDWR);
> +
> +		ret = pread(bmg_info[i].guid_fd, buf, sizeof(buf), 0);
> +		igt_assert_f(ret > 0, "failed to read guid for device %d\n", i);
> +		bmg_info[i].guid = strtol(buf, NULL, 16);
> +		igt_assert_f(bmg_info[i].guid > 0, "failed to set guid for device %d\n", i);
> +	}
> +}
> +
> +#define ENABLE_MSG "1\n"
> +#define DISABLE_MSG "0\n"
> +
> +static bool send_msg(int fd, const char *msg, const char *file) {
> +	size_t len = strlen(msg);
> +	int ret;
> +
> +	errno = 0;
> +	ret = pwrite(fd, msg, len, 0);
> +	if (ret != len)
> +		igt_info("%s failed: len: %ld vs %d  errno: %d\n", file, len, ret,
> +			 errno);
> +
> +	return ret == len;
> +}
> +
> +static bool verify_msg(int fd, const char *msg, const char *file) {
> +	size_t len = strlen(msg);
> +	char buf[32] = {};
> +	int ret;
> +
> +	errno = 0;
> +	ret = pread(fd, buf, sizeof(buf), 0);
> +	if (ret != len)
> +		igt_info("%s failed: len: %ld vs %d  errno: %d\n", file, len, ret, errno);
> +
> +	return ret == len && strcmp(buf, msg) == 0;
> +}
> +
> +/*
> + * Set enable enable/disable bit and verify usage
> + */
> +static void test_pmt_crashlog_enable(int dev_fd)
> +{
> +	u_int32_t guid;
> +	int fd;
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(bmg_info); i++) {
> +		fd = bmg_info[i].enable_fd;
> +		guid = bmg_info[i].guid;
> +
> +		/* force enable so we are in a known state */
> +		igt_assert_f(send_msg(fd, ENABLE_MSG, enable), "0x%x: send enable\n", guid);
> +		igt_assert_f(verify_msg(fd, ENABLE_MSG, enable), "0x%x: verify enable\n", guid);
> +
> +		/* disable */
> +		igt_assert_f(send_msg(fd, DISABLE_MSG, enable), "0x%x: send disable\n", guid);
> +		igt_assert_f(verify_msg(fd, DISABLE_MSG, enable), "0x%x: verify disable\n", guid);
> +
> +		/* re-enable so we can do more testing */
> +		igt_assert_f(send_msg(fd, ENABLE_MSG, enable), "0x%x: re-enable\n", guid);
> +		igt_assert_f(verify_msg(fd, ENABLE_MSG, enable), "0x%x: verify re-enable\n", guid);
> +	}
> +
> +}
> +
> +/*
> + * The error bit is set when a crashlog fails in HW.  It is read only so only
> + * need to verify that it is "0".
> + */
> +static void test_pmt_crashlog_error(int dev_fd)
> +{
> +	uint32_t guid;
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(bmg_info); i++) {
> +		guid = bmg_info[i].guid;
> +		igt_assert_f(verify_msg(bmg_info[i].error_fd, DISABLE_MSG, error),
> +			     "0x%x: error clear\n", guid);
> +	}
> +}
> +
> +/*
> + * The rearm bit is set at cold boot.  It cannot be reset unless are real crashlog
> + * occurs (i.e. setting trigger will not change its value).  Verify that it is "1".
> + */
> +static void test_pmt_crashlog_rearm(int dev_fd)
> +{
> +	uint32_t guid;
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(bmg_info); i++) {
> +		guid = bmg_info[i].guid;
> +		igt_assert_f(verify_msg(bmg_info[i].rearm_fd, ENABLE_MSG, rearm),
> +			     "0x%x: rearm set\n", guid);
> +	}
> +}
> +
> +//#define PMT_CRASHLOG_TRIGGER_ENABLE 1
> +#if PMT_CRASHLOG_TRIGGER_ENABLE

Sorry for the late reply. One idea that AI gave me and I liked:
Instead of the #if, make it a separate subtest, e.g. pmt-crashlog-trigger,
that does igt_skip_on_f(!getenv("IGT_PMT_DESTRUCTIVE"), ...)
(like meta_test.c), and add it to tests/intel-ci/xe.blocklist.txt.
Then it always builds, CI never runs it, and you run it by hand with

IGT_PMT_DESTRUCTIVE=1 --run-subtest pmt-crashlog-trigger.

with this change:

Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>

> +/*
> + * Set the manual trigger bit and make sure the data is not 0xdeadbeef
> + */
> +static void test_pmt_crashlog_trigger(int dev_fd)
> +{
> +	char buf[64] = {};
> +	u_int32_t *val;
> +	int crashlog_fd;
> +	int trigger_fd;
> +	u_int32_t guid;
> +	int len;
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(bmg_info); i++) {
> +		crashlog_fd = bmg_info[i].crashlog_fd;
> +		trigger_fd = bmg_info[i].trigger_fd;
> +		guid = bmg_info[i].guid;
> +
> +		/* make sure the bit is clear */
> +		igt_assert_f(verify_msg(trigger_fd, DISABLE_MSG, trigger), "0x%x: trigger clear\n",
> +			     guid);
> +		/* set the trigger bit (1 -> trigger)*/
> +		igt_assert_f(send_msg(trigger_fd, ENABLE_MSG, trigger), "0x%x: set trigger\n", guid);
> +
> +		/* sleep to let the HW do its thing */
> +		sleep(1);
> +
> +		/* make sure the bit is set */
> +		igt_assert_f(verify_msg(trigger_fd, ENABLE_MSG, trigger), "0x%x: trigger not set\n",
> +			     guid);
> +
> +		len = read(crashlog_fd, buf, sizeof(buf));
> +		igt_assert_f(len == sizeof(buf), "0x%x: failed to read crashlog data\n", guid);
> +
> +		val = (u_int32_t *)buf;
> +
> +		igt_assert_f(*val != 0xdeadbeef, "0x%x: invalid trigger value: : 0x%x", guid, *val);
> +	}
> +}
> +
> +/*
> + * After a crashlog has been "consumed" (read), setting this bit can be done.
> + * Verify that it is set correctly.
> + */
> +static void test_pmt_crashlog_consumed(int dev_fd)
> +{
> +	uint32_t guid;
> +	int fd;
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(bmg_info); i++) {
> +		fd = bmg_info[i].consumed_fd;
> +		guid = bmg_info[i].guid;
> +
> +		/* check, set, verify */
> +		igt_assert_f(verify_msg(fd, DISABLE_MSG, consumed), "0x%x: consumed clear\n", guid);
> +		igt_assert_f(send_msg(fd, ENABLE_MSG, consumed), "0x%x: set consumed\n", guid);
> +		/* sleep(1) to allow HW to set the bit */
> +		sleep(1);
> +		igt_assert_f(verify_msg(fd, ENABLE_MSG, consumed), "0x%x: verify consumed\n", guid);
> +	}
> +}
> +
> +/*
> + * Test the clear crashlog bit. After setting the crashlog data buffer should be
> + * set to 0xdeadbeef.
> + * BMG supports writing "1" to the clear file, but writing "0" (DISABLE_MSG) to trigger
> + * file is the "standard" usage, so test that usage.
> + * This bit cannot be cleared by software (i.e. reboot required).
> + */
> +static void test_pmt_crashlog_clear(int dev_fd)
> +{
> +	char buf[64] = {};
> +	u_int32_t guid;
> +	int crashlog_fd;
> +	int trigger_fd;
> +	int clear_fd;
> +	int *val;
> +	int len;
> +	int i;
> +
> +	for (i = 0; i < ARRAY_SIZE(bmg_info); i++) {
> +		clear_fd = bmg_info[i].clear_fd;
> +		crashlog_fd = bmg_info[i].crashlog_fd;
> +		trigger_fd = bmg_info[i].trigger_fd;
> +		guid = bmg_info[i].guid;
> +
> +		/* make sure the bit is clear */
> +		igt_assert_f(verify_msg(clear_fd, DISABLE_MSG, clear), "0x%x: verify clear\n", guid);
> +
> +		/* set the clear bit (0 -> trigger)*/
> +		igt_assert_f(send_msg(trigger_fd, DISABLE_MSG, trigger), "0x%x: send enable\n", guid);
> +
> +		/* make sure the bit is set.  sleep() to allow HW to set the bit */
> +		sleep(1);
> +		igt_assert_f(verify_msg(clear_fd, ENABLE_MSG, clear), "0x%x: clear set\n", guid);
> +
> +		len = read(crashlog_fd, buf, sizeof(buf));
> +		igt_assert_f(len == sizeof(buf), "0x%x: failed to read crashlog data\n", guid);
> +
> +		val = (int *)buf;
> +		igt_assert_f(*val == 0xdeadbeef, "0x%x: invalid clear data value: : 0x%x", guid, *val);
> +	}
> +}
> +#endif
> +
> +/**
> + * SUBTEST: pmt-bmg-all
> + * Description:
> + *   Because of how the Crashlog Instances behave, these tests are ordered. Do not use them
> + *   individually unless you understand the underlying HW behavior.  Because of this behavior,
> + *   all of the test will be done in order in one step.
> + *   NOTE:
> + *     o Testing MUST be done after a cold reset
> + *     o Once crashlog is triggered the device behavior is undefined and requires a cold reset
> + *
> + *  Test category: functionality test
> + */
> +static void test_pmt_bmg(int fd)
> +{
> +	test_pmt_directories(fd);
> +
> +	test_pmt_telemetry_files(fd);
> +	test_pmt_telemetry_read_data(fd);
> +
> +	test_pmt_crashlog_files(fd);
> +	test_pmt_crashlog_error(fd);
> +	test_pmt_crashlog_enable(fd);
> +	test_pmt_crashlog_rearm(fd);
> +
> +#if PMT_CRASHLOG_TRIGGER_ENABLE
> +	test_pmt_crashlog_trigger(fd);
> +	test_pmt_crashlog_consumed(fd);
> +	test_pmt_crashlog_clear(fd);
> +#endif
> +}
> +
> +int igt_main()
> +{
> +	const struct {
> +		const char *name;
> +		void (*func)(int);
> +	} funcs[] = {
> +		{ "pmt-bmg-all", test_pmt_bmg },
> +		{ }
> +	}, *f;
> +	int dev_fd;
> +
> +	igt_fixture() {
> +		uint16_t dev_id;
> +
> +		dev_fd = drm_open_driver(DRIVER_XE);
> +		dev_id = intel_get_drm_devid(dev_fd);
> +		igt_require_f(IS_BATTLEMAGE(dev_id), "PMT supported on BMG GPU\n");
> +	}
> +
> +	igt_describe("PMT access and API testing");
> +	for (f = funcs; f->name; f++) {
> +		igt_subtest_f("%s", f->name)
> +			f->func(dev_fd);
> +	}
> +
> +	igt_fixture()
> +		drm_close_driver(dev_fd);
> +}
> -- 
> 2.43.0
>