KVM: SEV: Do cache maintenance on the source VM during intra-host migrationgrafted

Manually perform cache maintenance on the source VM during intra-host
migration to ensure no stale data is left in CPU caches after the VM is
destroyed.  Because the source VM is "converted" to a non-SEV VM, KVM's
memory reclaim flows won't trigger cache maintenance, e.g. when all guest
memory is reclaimed in response to detaching from the mmu_notifier.

Note, relying on the destination VM to do cache maintenance isn't an option
as KVM doesn't require identical guest memory configurations, i.e. the
source VM may have access to memory that the destination VM does not.
Enforcing equivalent memory configurations is infeasible, as it would
require a *deep* comparison of memslots, e.g. to verify that not only are
the memslot identical, but what the memslots point at is also identical.

Fixes: b56639318bb2 ("KVM: SEV: Add support for SEV intra host migration")
Cc: stable@vger.kernel.org
Reported-by: Stefan Teodorescu <fane@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260923163721.1584779-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 436 insertions, 0 deletions

diff --git a/drivers/hid/hid-winwing.c b/drivers/hid/hid-winwing.c
new file mode 100644
index 000000000..9cd25a779
--- /dev/null
+++ b/drivers/hid/hid-winwing.c
@@ -0,0 +1,436 @@
+// SPDX-License-Identifier: GPL-2.0
+
+/*
+ * HID driver for WinWing Orion 2 throttle
+ *
+ * Copyright (c) 2023 Ivan Gorinov
+ */
+
+#include <linux/device.h>
+#include <linux/hid.h>
+#include <linux/hidraw.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/mutex.h>
+#include <linux/workqueue.h>
+
+#define MAX_REPORT 16
+
+struct winwing_led {
+	struct led_classdev cdev;
+	struct hid_device *hdev;
+	int number;
+};
+
+struct winwing_led_info {
+	int number;
+	int max_brightness;
+	const char *led_name;
+};
+
+static const struct winwing_led_info led_info[3] = {
+	{ 0, 255, "backlight" },
+	{ 1, 1, "a-a" },
+	{ 2, 1, "a-g" },
+};
+
+struct winwing_drv_data {
+	struct hid_device *hdev;
+	struct mutex lights_lock;
+	__u8 *report_lights;
+	__u8 *report_rumble;
+	struct work_struct rumble_work;
+	struct ff_rumble_effect rumble;
+	int rumble_left;
+	int rumble_right;
+	int has_grip15;
+	struct winwing_led leds[];
+};
+
+static int winwing_led_write(struct led_classdev *cdev,
+		enum led_brightness br)
+{
+	struct winwing_led *led = (struct winwing_led *) cdev;
+	struct winwing_drv_data *data = hid_get_drvdata(led->hdev);
+	__u8 *buf = data->report_lights;
+	int ret;
+
+	mutex_lock(&data->lights_lock);
+
+	/*
+	 * Mimicking requests captured by usbmon when LEDs
+	 * are controlled by the vendor's app in a VM.
+	 */
+	buf[0] = 0x02;
+	buf[1] = 0x60;
+	buf[2] = 0xbe;
+	buf[3] = 0x00;
+	buf[4] = 0x00;
+	buf[5] = 0x03;
+	buf[6] = 0x49;
+	buf[7] = led->number;
+	buf[8] = br;
+	buf[9] = 0x00;
+	buf[10] = 0;
+	buf[11] = 0;
+	buf[12] = 0;
+	buf[13] = 0;
+
+	ret = hid_hw_output_report(led->hdev, buf, 14);
+
+	mutex_unlock(&data->lights_lock);
+
+	return ret;
+}
+
+static int winwing_init_led(struct hid_device *hdev,
+		struct input_dev *input)
+{
+	struct winwing_drv_data *data;
+	struct winwing_led *led;
+	int ret;
+	int i;
+
+	data = hid_get_drvdata(hdev);
+
+	if (!data)
+		return -EINVAL;
+
+	data->report_lights = devm_kzalloc(&hdev->dev, MAX_REPORT, GFP_KERNEL);
+
+	if (!data->report_lights)
+		return -ENOMEM;
+
+	for (i = 0; i < 3; i += 1) {
+		const struct winwing_led_info *info = &led_info[i];
+
+		led = &data->leds[i];
+		led->hdev = hdev;
+		led->number = info->number;
+		led->cdev.max_brightness = info->max_brightness;
+		led->cdev.brightness_set_blocking = winwing_led_write;
+		led->cdev.flags = LED_HW_PLUGGABLE;
+		led->cdev.name = devm_kasprintf(&hdev->dev, GFP_KERNEL,
+						"%s::%s",
+						dev_name(&input->dev),
+						info->led_name);
+
+		if (!led->cdev.name)
+			return -ENOMEM;
+
+		ret = devm_led_classdev_register(&hdev->dev, &led->cdev);
+		if (ret)
+			return ret;
+	}
+
+	return ret;
+}
+
+static int winwing_map_button(int button, int has_grip15)
+{
+	if (button < 1)
+		return KEY_RESERVED;
+
+	if (button > 112)
+		return KEY_RESERVED;
+
+	if (button <= 16) {
+		/*
+		 * Grip buttons [1 .. 16] are mapped to
+		 * key codes BTN_TRIGGER .. BTN_DEAD
+		 */
+		return (button - 1) + BTN_JOYSTICK;
+	}
+
+	if (button >= 65) {
+		/*
+		 * Base buttons [65 .. 112] are mapped to
+		 * key codes BTN_TRIGGER_HAPPY17 .. KEY_MAX
+		 */
+		return (button - 65) + BTN_TRIGGER_HAPPY17;
+	}
+
+	if (!has_grip15) {
+		/*
+		 * Not mapping numbers [33 .. 64] which
+		 * are not assigned to any real buttons
+		 */
+		if (button >= 33)
+			return KEY_RESERVED;
+		/*
+		 * Grip buttons [17 .. 32] are mapped to
+		 * BTN_TRIGGER_HAPPY1 .. BTN_TRIGGER_HAPPY16
+		 */
+		return (button - 17) + BTN_TRIGGER_HAPPY1;
+	}
+
+	if (button >= 49) {
+		/*
+		 * Grip buttons [49 .. 64] are mapped to
+		 * BTN_TRIGGER_HAPPY1 .. BTN_TRIGGER_HAPPY16
+		 */
+		return (button - 49) + BTN_TRIGGER_HAPPY1;
+	}
+
+	/*
+	 * Grip buttons [17 .. 44] are mapped to
+	 * key codes KEY_MACRO1 .. KEY_MACRO28;
+	 * also mapping numbers [45 .. 48] which
+	 * are not assigned to any real buttons.
+	 */
+	return (button - 17) + KEY_MACRO1;
+}
+
+static int winwing_input_mapping(struct hid_device *hdev,
+	struct hid_input *hi, struct hid_field *field, struct hid_usage *usage,
+	unsigned long **bit, int *max)
+{
+	struct winwing_drv_data *data;
+	int code = KEY_RESERVED;
+	int button = 0;
+
+	data = hid_get_drvdata(hdev);
+
+	if (!data)
+		return -EINVAL;
+
+	if ((usage->hid & HID_USAGE_PAGE) != HID_UP_BUTTON)
+		return 0;
+
+	if (field->application != HID_GD_JOYSTICK)
+		return 0;
+
+	/* Button numbers start with 1 */
+	button = usage->hid & HID_USAGE;
+
+	code = winwing_map_button(button, data->has_grip15);
+
+	hid_map_usage(hi, usage, bit, max, EV_KEY, code);
+
+	return 1;
+}
+
+/*
+ * If x ≤ 0, return 0;
+ * if x is in [1 .. 65535], return a value in [1 .. 255]
+ */
+static inline int convert_magnitude(int x)
+{
+	if (x < 1)
+		return 0;
+
+	return ((x * 255) >> 16) + 1;
+}
+
+static int winwing_haptic_rumble(struct winwing_drv_data *data)
+{
+	__u8 *buf;
+	__u8 m;
+
+	if (!data)
+		return -EINVAL;
+
+	if (!data->hdev)
+		return -EINVAL;
+
+	buf = data->report_rumble;
+
+	if (!buf)
+		return -EINVAL;
+
+	m = convert_magnitude(data->rumble.strong_magnitude);
+	if (m != data->rumble_left) {
+		int ret;
+
+		/*
+		 * Mimicking requests captured by usbmon when rumble
+		 * is activated by the vendor's app in a VM.
+		 */
+		buf[0] = 0x02;
+		buf[1] = 0x01;
+		buf[2] = 0xbf;
+		buf[3] = 0x00;
+		buf[4] = 0x00;
+		buf[5] = 0x03;
+		buf[6] = 0x49;
+		buf[7] = 0x00;
+		buf[8] = m;
+		buf[9] = 0x00;
+		buf[10] = 0;
+		buf[11] = 0;
+		buf[12] = 0;
+		buf[13] = 0;
+
+		ret = hid_hw_output_report(data->hdev, buf, 14);
+		if (ret < 0) {
+			hid_err(data->hdev, "error %d (%*ph)\n", ret, 14, buf);
+			return ret;
+		}
+		data->rumble_left = m;
+	}
+
+	m = convert_magnitude(data->rumble.weak_magnitude);
+	if (m != data->rumble_right) {
+		int ret;
+
+		/*
+		 * Mimicking requests captured by usbmon when rumble
+		 * is activated by the vendor's app in a VM.
+		 */
+		buf[0] = 0x02;
+		buf[1] = 0x03;
+		buf[2] = 0xbf;
+		buf[3] = 0x00;
+		buf[4] = 0x00;
+		buf[5] = 0x03;
+		buf[6] = 0x49;
+		buf[7] = 0x00;
+		buf[8] = m;
+		buf[9] = 0x00;
+		buf[10] = 0;
+		buf[11] = 0;
+		buf[12] = 0;
+		buf[13] = 0;
+
+		ret = hid_hw_output_report(data->hdev, buf, 14);
+		if (ret < 0) {
+			hid_err(data->hdev, "error %d (%*ph)\n", ret, 14, buf);
+			return ret;
+		}
+		data->rumble_right = m;
+	}
+
+	return 0;
+}
+
+
+static void winwing_haptic_rumble_cb(struct work_struct *work)
+{
+	struct winwing_drv_data *data;
+
+	data = container_of(work, struct winwing_drv_data, rumble_work);
+	winwing_haptic_rumble(data);
+}
+
+static int winwing_play_effect(struct input_dev *dev, void *context,
+		struct ff_effect *effect)
+{
+	struct winwing_drv_data *data = (struct winwing_drv_data *) context;
+
+	if (effect->type != FF_RUMBLE)
+		return 0;
+
+	if (!data)
+		return -EINVAL;
+
+	data->rumble = effect->u.rumble;
+
+	return schedule_work(&data->rumble_work);
+}
+
+static int winwing_init_ff(struct hid_device *hdev, struct hid_input *hidinput)
+{
+	struct winwing_drv_data *data;
+
+	data = (struct winwing_drv_data *) hid_get_drvdata(hdev);
+	if (!data)
+		return -EINVAL;
+
+	data->report_rumble = devm_kzalloc(&hdev->dev, MAX_REPORT, GFP_KERNEL);
+	data->rumble_left = -1;
+	data->rumble_right = -1;
+
+	input_set_capability(hidinput->input, EV_FF, FF_RUMBLE);
+
+	return input_ff_create_memless(hidinput->input, data,
+			winwing_play_effect);
+}
+
+static int winwing_probe(struct hid_device *hdev,
+		const struct hid_device_id *id)
+{
+	struct winwing_drv_data *data;
+	size_t data_size = struct_size(data, leds, 3);
+	int ret;
+
+	ret = hid_parse(hdev);
+	if (ret) {
+		hid_err(hdev, "parse failed\n");
+		return ret;
+	}
+
+	data = devm_kzalloc(&hdev->dev, data_size, GFP_KERNEL);
+
+	if (!data)
+		return -ENOMEM;
+
+	data->hdev = hdev;
+	data->has_grip15 = id->driver_data;
+	hid_set_drvdata(hdev, data);
+
+	INIT_WORK(&data->rumble_work, winwing_haptic_rumble_cb);
+
+	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+	if (ret) {
+		hid_err(hdev, "hw start failed\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static void winwing_remove(struct hid_device *hdev)
+{
+	struct winwing_drv_data *data;
+
+	data = (struct winwing_drv_data *) hid_get_drvdata(hdev);
+
+	if (data)
+		cancel_work_sync(&data->rumble_work);
+
+	hid_hw_close(hdev);
+	hid_hw_stop(hdev);
+}
+
+static int winwing_input_configured(struct hid_device *hdev,
+		struct hid_input *hidinput)
+{
+	struct winwing_drv_data *data;
+	int ret;
+
+	data = (struct winwing_drv_data *) hid_get_drvdata(hdev);
+
+	ret = winwing_init_led(hdev, hidinput->input);
+
+	if (ret)
+		hid_err(hdev, "led init failed\n");
+
+	if (data->has_grip15)
+		winwing_init_ff(hdev, hidinput);
+
+	return ret;
+}
+
+/* Set driver_data to 1 for grips with rumble motor and more than 32 buttons */
+static const struct hid_device_id winwing_devices[] = {
+	{ HID_USB_DEVICE(0x4098, 0xbd65), .driver_data = 1 },  /* TGRIP-15E  */
+	{ HID_USB_DEVICE(0x4098, 0xbd64), .driver_data = 1 },  /* TGRIP-15EX */
+	{ HID_USB_DEVICE(0x4098, 0xbe68), .driver_data = 0 },  /* TGRIP-16EX */
+	{ HID_USB_DEVICE(0x4098, 0xbe62), .driver_data = 0 },  /* TGRIP-18   */
+	{}
+};
+
+MODULE_DEVICE_TABLE(hid, winwing_devices);
+
+static struct hid_driver winwing_driver = {
+	.name = "winwing",
+	.id_table = winwing_devices,
+	.input_configured = winwing_input_configured,
+	.input_mapping = winwing_input_mapping,
+	.probe = winwing_probe,
+	.remove = winwing_remove,
+};
+module_hid_driver(winwing_driver);
+
+MODULE_DESCRIPTION("HID driver for WinWing Orion 2 throttle");
+MODULE_LICENSE("GPL");