[PATCH i-g-t] tests/intel/xe_busted: Introduce a new test for Xe device busted state

[Rodrigo Vivi]

Let's inject a gt_reset failure that will put Xe device in the
new busted state, then we confirm the IOCTL is blocked and we
reload the driver to get back to a clean state for other test
execution, since busted state in Xe is a final state that can only
be cleared with a device rebind/reprobe.

The fault injection of this test is entirely based on xe_uevent
provided by Himal.

v2: Use rebind instead of module reload (Lucas)
    And other improvements also pointed out by Lucas.

Cc: Lucas De Marchi <lucas.demarchi at intel.com>
Cc:  Himal Prasad Ghimiray <himal.prasad.ghimiray at intel.com>
Signed-off-by: Rodrigo Vivi <rodrigo.vivi at intel.com>
---
 tests/intel/xe_busted.c | 107 ++++++++++++++++++++++++++++++++++++++++
 tests/meson.build       |   1 +
 2 files changed, 108 insertions(+)
 create mode 100644 tests/intel/xe_busted.c

diff --git a/tests/intel/xe_busted.c b/tests/intel/xe_busted.c
new file mode 100644
index 000000000..88278213d
--- /dev/null
+++ b/tests/intel/xe_busted.c
@@ -0,0 +1,107 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2024 Intel Corporation
+ */
+
+/**
+ * TEST: cause fake gt reset failure which put Xe device in busted state
+ * Category: Software building block
+ * Sub-category: driver
+ * Functionality: busted
+ * Test category: functionality test
+ */
+
+#include <limits.h>
+#include <dirent.h>
+
+#include "igt.h"
+#include "igt_device.h"
+#include "igt_kmod.h"
+#include "igt_sysfs.h"
+
+#include "xe/xe_ioctl.h"
+
+static void force_busted(int fd)
+{
+	igt_debugfs_write(fd, "fail_gt_reset/probability", "100");
+	igt_debugfs_write(fd, "fail_gt_reset/times", "2");
+
+	xe_force_gt_reset(fd, 0);
+	sleep(1);
+}
+
+static int rebind_xe(int fd)
+{
+	char pci_slot[NAME_MAX];
+	int sysfs;
+
+	igt_device_get_pci_slot_name(fd, pci_slot);
+
+	sysfs = open("/sys/bus/pci/drivers/xe", O_DIRECTORY);
+	igt_assert(sysfs);
+
+        igt_assert(igt_sysfs_set(sysfs, "unbind", pci_slot));
+
+	/*
+	 * We need to close the client for a proper release, before
+	 * binding back again.
+	 */
+	close(fd);
+
+        igt_assert(igt_sysfs_set(sysfs, "bind", pci_slot));
+	close(sysfs);
+
+	/* Renew the client connection */
+	fd = drm_open_driver(DRIVER_XE);
+	igt_assert(fd);
+
+	return fd;
+}
+
+static int simple_ioctl(int fd)
+{
+	int ret;
+
+	struct drm_xe_vm_create create = {
+		.extensions = 0,
+		.flags = 0,
+	};
+
+	ret = igt_ioctl(fd, DRM_IOCTL_XE_VM_CREATE, &create);
+
+	if (ret == 0)
+		xe_vm_destroy(fd, create.vm_id);
+
+	return ret;
+}
+
+/**
+ * SUBTEST: basic-busted
+ * Description: Force Xe device busted after injecting a failure in GT reset
+ */
+igt_main
+{
+	int fd;
+
+	igt_fixture {
+		fd = drm_open_driver(DRIVER_XE);
+		igt_require(igt_debugfs_exists(fd, "fail_gt_reset/probability",
+					       O_RDWR));
+	}
+
+	igt_subtest("basic-busted") {
+		igt_assert_eq(simple_ioctl(fd), 0);
+		force_busted(fd);
+		igt_assert_neq(simple_ioctl(fd), 0);
+		fd = rebind_xe(fd);
+		igt_assert_eq(simple_ioctl(fd), 0);
+	}
+
+	igt_fixture {
+		if (igt_debugfs_exists(fd, "fail_gt_reset/probability", O_RDWR)) {
+			igt_debugfs_write(fd, "fail_gt_reset/probability", "0");
+			igt_debugfs_write(fd, "fail_gt_reset/times", "1");
+		}
+		drm_close_driver(fd);
+	}
+}
diff --git a/tests/meson.build b/tests/meson.build
index a856510fc..87a531051 100644
--- a/tests/meson.build
+++ b/tests/meson.build
@@ -274,6 +274,7 @@ intel_kms_progs = [
 ]
 
 intel_xe_progs = [
+	'xe_busted',
 	'xe_ccs',
 	'xe_create',
 	'xe_compute',
-- 
2.44.0