[PATCH] tests/intel: Add xe_coredump test, v2.

[Maarten Lankhorst]

Add a simple test that forces a GPU hang and then reads the resulting
devcoredump file. Map a single userptr and BO, and dump the contents of
those.

Changes since v1:
- Almost completely rewrite test for readability, based on feedback.

Signed-off-by: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
---
 tests/intel/xe_coredump.c | 256 ++++++++++++++++++++++++++++++++++++++
 tests/meson.build         |   1 +
 2 files changed, 257 insertions(+)
 create mode 100644 tests/intel/xe_coredump.c

diff --git a/tests/intel/xe_coredump.c b/tests/intel/xe_coredump.c
new file mode 100644
index 000000000..add9508f5
--- /dev/null
+++ b/tests/intel/xe_coredump.c
@@ -0,0 +1,256 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2023 Intel Corporation
+ */
+
+/**
+ * TEST: Check devcoredump functionality
+ * Category: Software building block
+ * Sub-category: devcoredump
+ * Run type: BAT
+ * Functionality: Error dumping and readout.
+ */
+
+#include <unistd.h>
+#include <fcntl.h>
+#include <glob.h>
+#include <string.h>
+#include <wchar.h>
+#include <sys/stat.h>
+
+#include "igt.h"
+#include "igt_device.h"
+#include "igt_io.h"
+#include "igt_syncobj.h"
+#include "igt_sysfs.h"
+
+#include "intel_pat.h"
+
+#include "xe_drm.h"
+#include "xe/xe_ioctl.h"
+#include "xe/xe_query.h"
+
+#ifndef DRM_XE_VM_BIND_FLAG_DUMPABLE
+#define DRM_XE_VM_BIND_FLAG_DUMPABLE (1<<3)
+#endif
+
+static struct xe_device *xe;
+static uint32_t batch_bo;
+static uint32_t *batch;
+static void *userptr;
+static uint32_t vm;
+static int sysfd;
+
+#define MAX_N_ENGINES 32
+
+static void tryclear_hang(void)
+{
+	int fd = openat(sysfd, "devcoredump/data", O_RDWR);
+	char buf[256];
+
+	if (fd < 0)
+		return;
+
+	while (read(fd, buf, sizeof(buf)) > 0)
+		{ }
+	write(fd, "1", 1);
+	close(fd);
+}
+
+/*
+ * Helper to read and clear devcore.  We want to read it completely to ensure
+ * we catch any kernel side regressions like:
+ * https://gitlab.freedesktop.org/drm/msm/-/issues/20
+ */
+static void
+read_and_clear_hang(void)
+{
+	char buf[0x1000];
+	int try, fd;
+	for (try = 0; try < 5; try++) {
+		fd = openat(sysfd, "devcoredump/data", O_RDWR);
+		if (fd >= 0)
+			break;
+	}
+	igt_assert(fd >= 0);
+
+	/*
+	 * We want to read the entire file but we can throw away the
+	 * contents.. we just want to make sure that we exercise the
+	 * kernel side codepaths hit when reading the devcore from
+	 * sysfs
+	 */
+	igt_debug("---- begin coredump ----\n");
+	while (1) {
+		ssize_t ret;
+
+		ret = igt_readn(fd, buf, sizeof(buf) - 1);
+		igt_assert(ret >= 0);
+		if (ret == 0)
+			break;
+		buf[ret] = '\0';
+		igt_debug("%s", buf);
+	}
+
+	igt_debug("---- end coredump ----\n");
+
+	/* Clear the devcore: */
+	igt_writen(fd, "1", 1);
+
+	close(fd);
+}
+
+static void free_execqueue(void)
+{
+	int fd = xe->fd;
+	xe_vm_destroy(fd, vm);
+	vm = 0;
+	gem_close(fd, batch_bo);
+	munmap(batch, xe->default_alignment);
+	munmap(userptr, xe->default_alignment);
+	batch = userptr = NULL;
+}
+
+static void recreate_execqueue(bool dumpable)
+{
+	struct drm_xe_sync sync = {
+		.type = DRM_XE_SYNC_TYPE_SYNCOBJ,
+		.flags = DRM_XE_SYNC_FLAG_SIGNAL,
+	};
+	struct drm_xe_vm_bind_op bind_ops[2] = { };
+	int fd = xe->fd;
+	uint32_t *ptr;
+	uint64_t offset = xe->default_alignment - 4;
+
+	tryclear_hang();
+
+	if (vm)
+		free_execqueue();
+
+	vm = xe_vm_create(fd, 0, 0);
+	batch_bo = xe_bo_create(fd, vm, xe->default_alignment, system_memory(fd), 0);
+	ptr = batch = xe_bo_map(xe->fd, batch_bo, xe->default_alignment);
+
+	memset(batch, 0, xe->default_alignment);
+	*(ptr++) = MI_SEMAPHORE_WAIT | MI_SEMAPHORE_POLL | MI_SEMAPHORE_SAD_GTE_SDD;
+	*(ptr++) = 1;
+	*(ptr++) = offset >> 32;
+	*(ptr++) = offset;
+	*(ptr++) = MI_BATCH_BUFFER_END;
+
+	userptr = mmap(0, xe->default_alignment, PROT_WRITE, MAP_SHARED | MAP_ANON, -1, 0);
+	wmemset(userptr, 0xf1234567, xe->default_alignment / sizeof(wchar_t));
+
+	bind_ops[0].op = DRM_XE_VM_BIND_OP_MAP;
+	bind_ops[0].obj = batch_bo;
+	bind_ops[0].addr = 0;
+
+	bind_ops[1].op = DRM_XE_VM_BIND_OP_MAP_USERPTR;
+	bind_ops[1].userptr = (size_t)userptr;
+	bind_ops[1].addr = 1ULL << 40ULL;
+
+	if (dumpable)
+		bind_ops[0].flags = bind_ops[1].flags = DRM_XE_VM_BIND_FLAG_DUMPABLE;
+	bind_ops[0].range = bind_ops[1].range = xe->default_alignment;
+	bind_ops[0].pat_index = bind_ops[1].pat_index = intel_get_pat_idx_wb(fd);
+
+	sync.handle = syncobj_create(fd, 0);
+	xe_vm_bind_array(fd, vm, 0, bind_ops, ARRAY_SIZE(bind_ops), &sync, 1);
+	syncobj_wait(fd, &sync.handle, 1, INT64_MAX, 0, NULL);
+	syncobj_destroy(fd, sync.handle);
+}
+
+static uint32_t hang_engine(struct drm_xe_engine_class_instance *hwe)
+{
+	uint32_t engine;
+	struct drm_xe_sync sync = {
+		.type = DRM_XE_SYNC_TYPE_SYNCOBJ,
+		.flags = DRM_XE_SYNC_FLAG_SIGNAL,
+		.handle = syncobj_create(xe->fd, 0),
+	};
+
+	engine = xe_exec_queue_create(xe->fd, vm, hwe, 0);
+	xe_exec_sync(xe->fd, engine, 0, &sync, 1);
+
+	return sync.handle;
+}
+
+static void test_hang_one(void)
+{
+	uint32_t syncobj = hang_engine(&xe_engine(xe->fd, 0)->instance);
+
+	syncobj_wait(xe->fd, &syncobj, 1, INT64_MAX, 0, NULL);
+	syncobj_destroy(xe->fd, syncobj);
+
+	read_and_clear_hang();
+}
+
+/**
+ * SUBTEST: basic
+ * Description: Read out a full dumped VM.
+ * Test category: functionality test
+ */
+static void basic(void)
+{
+	recreate_execqueue(true);
+	test_hang_one();
+}
+
+/**
+ * SUBTEST: empty-vm
+ * Description: Create an error dump without anything in VM to dump.
+ * Test category: functionality test
+ */
+static void empty_vm(void)
+{
+	recreate_execqueue(false);
+	test_hang_one();
+}
+
+/**
+ * SUBTEST: all-simultaneously
+ * Description: Hang all engines at the same time, read out the dump.
+ * Test category: robustness test
+ */
+static void all_simultaneously(void)
+{
+	uint32_t syncobj[MAX_N_ENGINES], i = 0;
+	struct drm_xe_engine_class_instance *hwe;
+
+	recreate_execqueue(true);
+	xe_for_each_engine(xe->fd, hwe)
+		syncobj[i++] = hang_engine(hwe);
+
+	syncobj_wait(xe->fd, syncobj, i, INT64_MAX, 0, NULL);
+	while (i--)
+		syncobj_destroy(xe->fd, syncobj[i]);
+
+	read_and_clear_hang();
+}
+
+igt_main
+{
+	igt_fixture {
+		struct stat stat;
+		int fd = drm_open_driver_render(DRIVER_XE);
+		char str[256];
+		xe = xe_device_get(fd);
+
+		igt_assert_eq(fstat(fd, &stat), 0);
+		sprintf(str, "/sys/dev/char/%ld:%ld/device", stat.st_rdev >> 8, stat.st_rdev & 0xff);
+		sysfd = open(str, O_DIRECTORY);
+		igt_assert(sysfd >= 0);
+	}
+
+	igt_describe("Test that hw fault coredump readout works");
+	igt_subtest("basic")
+		basic();
+
+	igt_describe("Hang all engines simultaneously");
+	igt_subtest("all-simultaneously")
+		all_simultaneously();
+
+	igt_describe("Ensure that snapshot works without anything to capture");
+	igt_subtest("empty-vm")
+		empty_vm();
+}
diff --git a/tests/meson.build b/tests/meson.build
index d107d16fa..331d88c8e 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -280,6 +280,7 @@ intel_xe_progs = [
 	'xe_compute',
 	'xe_compute_preempt',
 	'xe_copy_basic',
+	'xe_coredump',
 	'xe_dma_buf_sync',
 	'xe_debugfs',
 	'xe_drm_fdinfo',
-- 
2.43.0