KVM: Don't pre-reserve xarray entries when storing empty/NULL attributesgrafted

Skip the xarray reservation loop when clearing all memory attributes, as
storing NULL only erases the entry and never needs to allocate, so no
reservation (and no cleanup of a failed one) is required in that case.

Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: David Ballesteros <davimaba.v@proton.me>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com
[sean: split to separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>

1 files changed, 222 insertions, 0 deletions

diff --git a/drivers/hid/hid-uclogic-params-test.c b/drivers/hid/hid-uclogic-params-test.c
new file mode 100644
index 000000000..a30121419
--- /dev/null
+++ b/drivers/hid/hid-uclogic-params-test.c
@@ -0,0 +1,222 @@
+// SPDX-License-Identifier: GPL-2.0+
+
+/*
+ *  HID driver for UC-Logic devices not fully compliant with HID standard
+ *
+ *  Copyright (c) 2022 José Expósito <jose.exposito89@gmail.com>
+ */
+
+#include <kunit/test.h>
+#include "./hid-uclogic-params.h"
+#include "./hid-uclogic-rdesc.h"
+
+#define MAX_STR_DESC_SIZE 14
+
+struct uclogic_parse_ugee_v2_desc_case {
+	const char *name;
+	int res;
+	const __u8 str_desc[MAX_STR_DESC_SIZE];
+	size_t str_desc_size;
+	const s32 desc_params[UCLOGIC_RDESC_PH_ID_NUM];
+	enum uclogic_params_frame_type frame_type;
+};
+
+static struct uclogic_parse_ugee_v2_desc_case uclogic_parse_ugee_v2_desc_cases[] = {
+	{
+		.name = "invalid_str_desc",
+		.res = -EINVAL,
+		.str_desc = {},
+		.str_desc_size = 0,
+		.desc_params = {},
+		.frame_type = UCLOGIC_PARAMS_FRAME_BUTTONS,
+	},
+	{
+		.name = "resolution_with_value_0",
+		.res = 0,
+		.str_desc = {
+			0x0E, 0x03,
+			0x70, 0xB2,
+			0x10, 0x77,
+			0x08,
+			0x00,
+			0xFF, 0x1F,
+			0x00, 0x00,
+		},
+		.str_desc_size = 12,
+		.desc_params = {
+			[UCLOGIC_RDESC_PEN_PH_ID_X_LM] = 0xB270,
+			[UCLOGIC_RDESC_PEN_PH_ID_X_PM] = 0,
+			[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] = 0x7710,
+			[UCLOGIC_RDESC_PEN_PH_ID_Y_PM] = 0,
+			[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM] = 0x1FFF,
+			[UCLOGIC_RDESC_FRAME_PH_ID_UM] = 0x08,
+		},
+		.frame_type = UCLOGIC_PARAMS_FRAME_BUTTONS,
+	},
+	/* XP-PEN Deco L str_desc: Frame with 8 buttons */
+	{
+		.name = "frame_type_buttons",
+		.res = 0,
+		.str_desc = {
+			0x0E, 0x03,
+			0x70, 0xB2,
+			0x10, 0x77,
+			0x08,
+			0x00,
+			0xFF, 0x1F,
+			0xD8, 0x13,
+		},
+		.str_desc_size = 12,
+		.desc_params = {
+			[UCLOGIC_RDESC_PEN_PH_ID_X_LM] = 0xB270,
+			[UCLOGIC_RDESC_PEN_PH_ID_X_PM] = 0x2320,
+			[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] = 0x7710,
+			[UCLOGIC_RDESC_PEN_PH_ID_Y_PM] = 0x1770,
+			[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM] = 0x1FFF,
+			[UCLOGIC_RDESC_FRAME_PH_ID_UM] = 0x08,
+		},
+		.frame_type = UCLOGIC_PARAMS_FRAME_BUTTONS,
+	},
+	/* PARBLO A610 PRO str_desc: Frame with 9 buttons and dial */
+	{
+		.name = "frame_type_dial",
+		.res = 0,
+		.str_desc = {
+			0x0E, 0x03,
+			0x96, 0xC7,
+			0xF9, 0x7C,
+			0x09,
+			0x01,
+			0xFF, 0x1F,
+			0xD8, 0x13,
+		},
+		.str_desc_size = 12,
+		.desc_params = {
+			[UCLOGIC_RDESC_PEN_PH_ID_X_LM] = 0xC796,
+			[UCLOGIC_RDESC_PEN_PH_ID_X_PM] = 0x2749,
+			[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] = 0x7CF9,
+			[UCLOGIC_RDESC_PEN_PH_ID_Y_PM] = 0x1899,
+			[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM] = 0x1FFF,
+			[UCLOGIC_RDESC_FRAME_PH_ID_UM] = 0x09,
+		},
+		.frame_type = UCLOGIC_PARAMS_FRAME_DIAL,
+	},
+	/* XP-PEN Deco Pro S str_desc: Frame with 8 buttons and mouse */
+	{
+		.name = "frame_type_mouse",
+		.res = 0,
+		.str_desc = {
+			0x0E, 0x03,
+			0xC8, 0xB3,
+			0x34, 0x65,
+			0x08,
+			0x02,
+			0xFF, 0x1F,
+			0xD8, 0x13,
+		},
+		.str_desc_size = 12,
+		.desc_params = {
+			[UCLOGIC_RDESC_PEN_PH_ID_X_LM] = 0xB3C8,
+			[UCLOGIC_RDESC_PEN_PH_ID_X_PM] = 0x2363,
+			[UCLOGIC_RDESC_PEN_PH_ID_Y_LM] = 0x6534,
+			[UCLOGIC_RDESC_PEN_PH_ID_Y_PM] = 0x13EC,
+			[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM] = 0x1FFF,
+			[UCLOGIC_RDESC_FRAME_PH_ID_UM] = 0x08,
+		},
+		.frame_type = UCLOGIC_PARAMS_FRAME_MOUSE,
+	},
+};
+
+static void uclogic_parse_ugee_v2_desc_case_desc(struct uclogic_parse_ugee_v2_desc_case *t,
+						 char *desc)
+{
+	strscpy(desc, t->name, KUNIT_PARAM_DESC_SIZE);
+}
+
+KUNIT_ARRAY_PARAM(uclogic_parse_ugee_v2_desc, uclogic_parse_ugee_v2_desc_cases,
+		  uclogic_parse_ugee_v2_desc_case_desc);
+
+static void hid_test_uclogic_parse_ugee_v2_desc(struct kunit *test)
+{
+	int res;
+	s32 desc_params[UCLOGIC_RDESC_PH_ID_NUM];
+	enum uclogic_params_frame_type frame_type;
+	const struct uclogic_parse_ugee_v2_desc_case *params = test->param_value;
+
+	res = uclogic_params_parse_ugee_v2_desc(params->str_desc,
+						params->str_desc_size,
+						desc_params,
+						ARRAY_SIZE(desc_params),
+						&frame_type);
+	KUNIT_ASSERT_EQ(test, res, params->res);
+
+	if (res)
+		return;
+
+	KUNIT_EXPECT_EQ(test,
+			params->desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_LM],
+			desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_LM]);
+	KUNIT_EXPECT_EQ(test,
+			params->desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_PM],
+			desc_params[UCLOGIC_RDESC_PEN_PH_ID_X_PM]);
+	KUNIT_EXPECT_EQ(test,
+			params->desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_LM],
+			desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_LM]);
+	KUNIT_EXPECT_EQ(test,
+			params->desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_PM],
+			desc_params[UCLOGIC_RDESC_PEN_PH_ID_Y_PM]);
+	KUNIT_EXPECT_EQ(test,
+			params->desc_params[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM],
+			desc_params[UCLOGIC_RDESC_PEN_PH_ID_PRESSURE_LM]);
+	KUNIT_EXPECT_EQ(test,
+			params->desc_params[UCLOGIC_RDESC_FRAME_PH_ID_UM],
+			desc_params[UCLOGIC_RDESC_FRAME_PH_ID_UM]);
+	KUNIT_EXPECT_EQ(test, params->frame_type, frame_type);
+}
+
+struct fake_device {
+	unsigned long quirks;
+};
+
+static void hid_test_uclogic_params_cleanup_event_hooks(struct kunit *test)
+{
+	int res, n;
+	struct hid_device *hdev;
+	struct fake_device *fake_dev;
+	struct uclogic_params p = {0, };
+
+	hdev = kunit_kzalloc(test, sizeof(struct hid_device), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, hdev);
+
+	fake_dev = kunit_kzalloc(test, sizeof(struct fake_device), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, fake_dev);
+
+	hid_set_drvdata(hdev, fake_dev);
+
+	res = uclogic_params_ugee_v2_init_event_hooks(hdev, &p);
+	KUNIT_ASSERT_EQ(test, res, 0);
+
+	/* Check that the function can be called repeatedly */
+	for (n = 0; n < 4; n++) {
+		uclogic_params_cleanup_event_hooks(&p);
+		KUNIT_EXPECT_PTR_EQ(test, p.event_hooks, NULL);
+	}
+}
+
+static struct kunit_case hid_uclogic_params_test_cases[] = {
+	KUNIT_CASE_PARAM(hid_test_uclogic_parse_ugee_v2_desc,
+			 uclogic_parse_ugee_v2_desc_gen_params),
+	KUNIT_CASE(hid_test_uclogic_params_cleanup_event_hooks),
+	{}
+};
+
+static struct kunit_suite hid_uclogic_params_test_suite = {
+	.name = "hid_uclogic_params_test",
+	.test_cases = hid_uclogic_params_test_cases,
+};
+
+kunit_test_suite(hid_uclogic_params_test_suite);
+
+MODULE_DESCRIPTION("KUnit tests for the UC-Logic driver");
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("José Expósito <jose.exposito89@gmail.com>");