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, 589 insertions, 0 deletions

diff --git a/drivers/input/keyboard/samsung-keypad.c b/drivers/input/keyboard/samsung-keypad.c
new file mode 100644
index 000000000..deffa9874
--- /dev/null
+++ b/drivers/input/keyboard/samsung-keypad.c
@@ -0,0 +1,589 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Samsung keypad driver
+ *
+ * Copyright (C) 2010 Samsung Electronics Co.Ltd
+ * Author: Joonyoung Shim <jy0922.shim@samsung.com>
+ * Author: Donghwa Lee <dh09.lee@samsung.com>
+ */
+
+#include <linux/bits.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/err.h>
+#include <linux/input.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/pm.h>
+#include <linux/pm_runtime.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/sched.h>
+#include <linux/input/samsung-keypad.h>
+
+#define SAMSUNG_KEYIFCON			0x00
+#define SAMSUNG_KEYIFSTSCLR			0x04
+#define SAMSUNG_KEYIFCOL			0x08
+#define SAMSUNG_KEYIFROW			0x0c
+#define SAMSUNG_KEYIFFC				0x10
+
+/* SAMSUNG_KEYIFCON */
+#define SAMSUNG_KEYIFCON_INT_F_EN		BIT(0)
+#define SAMSUNG_KEYIFCON_INT_R_EN		BIT(1)
+#define SAMSUNG_KEYIFCON_DF_EN			BIT(2)
+#define SAMSUNG_KEYIFCON_FC_EN			BIT(3)
+#define SAMSUNG_KEYIFCON_WAKEUPEN		BIT(4)
+
+/* SAMSUNG_KEYIFSTSCLR */
+#define SAMSUNG_KEYIFSTSCLR_P_INT_MASK		(0xff << 0)
+#define SAMSUNG_KEYIFSTSCLR_R_INT_MASK		(0xff << 8)
+#define SAMSUNG_KEYIFSTSCLR_R_INT_OFFSET	8
+#define S5PV210_KEYIFSTSCLR_P_INT_MASK		(0x3fff << 0)
+#define S5PV210_KEYIFSTSCLR_R_INT_MASK		(0x3fff << 16)
+#define S5PV210_KEYIFSTSCLR_R_INT_OFFSET	16
+
+/* SAMSUNG_KEYIFCOL */
+#define SAMSUNG_KEYIFCOL_MASK			0xff
+
+/* SAMSUNG_KEYIFROW */
+#define SAMSUNG_KEYIFROW_MASK			(0xff << 0)
+#define S5PV210_KEYIFROW_MASK			(0x3fff << 0)
+
+/* SAMSUNG_KEYIFFC */
+#define SAMSUNG_KEYIFFC_MASK			(0x3ff << 0)
+
+struct samsung_chip_info {
+	unsigned int column_shift;
+};
+
+struct samsung_keypad {
+	const struct samsung_chip_info *chip;
+	struct input_dev *input_dev;
+	struct platform_device *pdev;
+	struct clk *clk;
+	void __iomem *base;
+	wait_queue_head_t wait;
+	bool stopped;
+	bool wake_enabled;
+	int irq;
+	unsigned int row_shift;
+	unsigned int rows;
+	unsigned int cols;
+	unsigned int row_state[SAMSUNG_MAX_COLS];
+	unsigned short keycodes[];
+};
+
+static void samsung_keypad_scan(struct samsung_keypad *keypad,
+				unsigned int *row_state)
+{
+	unsigned int col;
+	unsigned int val;
+
+	for (col = 0; col < keypad->cols; col++) {
+		val = SAMSUNG_KEYIFCOL_MASK & ~BIT(col);
+		val <<= keypad->chip->column_shift;
+
+		writel(val, keypad->base + SAMSUNG_KEYIFCOL);
+		mdelay(1);
+
+		val = readl(keypad->base + SAMSUNG_KEYIFROW);
+		row_state[col] = ~val & GENMASK(keypad->rows - 1, 0);
+	}
+
+	/* KEYIFCOL reg clear */
+	writel(0, keypad->base + SAMSUNG_KEYIFCOL);
+}
+
+static bool samsung_keypad_report(struct samsung_keypad *keypad,
+				  unsigned int *row_state)
+{
+	struct input_dev *input_dev = keypad->input_dev;
+	unsigned int changed;
+	unsigned int pressed;
+	unsigned int key_down = 0;
+	unsigned int val;
+	unsigned int col, row;
+
+	for (col = 0; col < keypad->cols; col++) {
+		changed = row_state[col] ^ keypad->row_state[col];
+		key_down |= row_state[col];
+		if (!changed)
+			continue;
+
+		for (row = 0; row < keypad->rows; row++) {
+			if (!(changed & BIT(row)))
+				continue;
+
+			pressed = row_state[col] & BIT(row);
+
+			dev_dbg(&keypad->input_dev->dev,
+				"key %s, row: %d, col: %d\n",
+				pressed ? "pressed" : "released", row, col);
+
+			val = MATRIX_SCAN_CODE(row, col, keypad->row_shift);
+
+			input_event(input_dev, EV_MSC, MSC_SCAN, val);
+			input_report_key(input_dev,
+					keypad->keycodes[val], pressed);
+		}
+		input_sync(keypad->input_dev);
+	}
+
+	memcpy(keypad->row_state, row_state, sizeof(keypad->row_state));
+
+	return key_down;
+}
+
+static irqreturn_t samsung_keypad_irq(int irq, void *dev_id)
+{
+	struct samsung_keypad *keypad = dev_id;
+	unsigned int row_state[SAMSUNG_MAX_COLS];
+	bool key_down;
+
+	guard(pm_runtime_active)(&keypad->pdev->dev);
+
+	do {
+		readl(keypad->base + SAMSUNG_KEYIFSTSCLR);
+		/* Clear interrupt. */
+		writel(~0x0, keypad->base + SAMSUNG_KEYIFSTSCLR);
+
+		samsung_keypad_scan(keypad, row_state);
+
+		key_down = samsung_keypad_report(keypad, row_state);
+		if (key_down)
+			wait_event_timeout(keypad->wait, keypad->stopped,
+					   msecs_to_jiffies(50));
+
+	} while (key_down && !keypad->stopped);
+
+	return IRQ_HANDLED;
+}
+
+static void samsung_keypad_start(struct samsung_keypad *keypad)
+{
+	unsigned int val;
+
+	guard(pm_runtime_active)(&keypad->pdev->dev);
+
+	/* Tell IRQ thread that it may poll the device. */
+	keypad->stopped = false;
+
+	clk_enable(keypad->clk);
+
+	/* Enable interrupt bits. */
+	val = readl(keypad->base + SAMSUNG_KEYIFCON);
+	val |= SAMSUNG_KEYIFCON_INT_F_EN | SAMSUNG_KEYIFCON_INT_R_EN;
+	writel(val, keypad->base + SAMSUNG_KEYIFCON);
+
+	/* KEYIFCOL reg clear. */
+	writel(0, keypad->base + SAMSUNG_KEYIFCOL);
+
+	enable_irq(keypad->irq);
+}
+
+static void samsung_keypad_stop(struct samsung_keypad *keypad)
+{
+	unsigned int val;
+
+	guard(pm_runtime_active)(&keypad->pdev->dev);
+
+	/* Signal IRQ thread to stop polling and disable the handler. */
+	keypad->stopped = true;
+	wake_up(&keypad->wait);
+	disable_irq(keypad->irq);
+
+	/* Clear interrupt. */
+	writel(~0x0, keypad->base + SAMSUNG_KEYIFSTSCLR);
+
+	/* Disable interrupt bits. */
+	val = readl(keypad->base + SAMSUNG_KEYIFCON);
+	val &= ~(SAMSUNG_KEYIFCON_INT_F_EN | SAMSUNG_KEYIFCON_INT_R_EN);
+	writel(val, keypad->base + SAMSUNG_KEYIFCON);
+
+	clk_disable(keypad->clk);
+}
+
+static int samsung_keypad_open(struct input_dev *input_dev)
+{
+	struct samsung_keypad *keypad = input_get_drvdata(input_dev);
+
+	samsung_keypad_start(keypad);
+
+	return 0;
+}
+
+static void samsung_keypad_close(struct input_dev *input_dev)
+{
+	struct samsung_keypad *keypad = input_get_drvdata(input_dev);
+
+	samsung_keypad_stop(keypad);
+}
+
+#ifdef CONFIG_OF
+static struct samsung_keypad_platdata *
+samsung_keypad_parse_dt(struct device *dev)
+{
+	struct samsung_keypad_platdata *pdata;
+	struct matrix_keymap_data *keymap_data;
+	uint32_t *keymap, num_rows = 0, num_cols = 0;
+	struct device_node *np = dev->of_node, *key_np;
+	unsigned int key_count;
+
+	if (!np) {
+		dev_err(dev, "missing device tree data\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
+	if (!pdata) {
+		dev_err(dev, "could not allocate memory for platform data\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	of_property_read_u32(np, "samsung,keypad-num-rows", &num_rows);
+	of_property_read_u32(np, "samsung,keypad-num-columns", &num_cols);
+	if (!num_rows || !num_cols) {
+		dev_err(dev, "number of keypad rows/columns not specified\n");
+		return ERR_PTR(-EINVAL);
+	}
+	pdata->rows = num_rows;
+	pdata->cols = num_cols;
+
+	keymap_data = devm_kzalloc(dev, sizeof(*keymap_data), GFP_KERNEL);
+	if (!keymap_data) {
+		dev_err(dev, "could not allocate memory for keymap data\n");
+		return ERR_PTR(-ENOMEM);
+	}
+	pdata->keymap_data = keymap_data;
+
+	key_count = of_get_child_count(np);
+	keymap_data->keymap_size = key_count;
+	keymap = devm_kcalloc(dev, key_count, sizeof(uint32_t), GFP_KERNEL);
+	if (!keymap) {
+		dev_err(dev, "could not allocate memory for keymap\n");
+		return ERR_PTR(-ENOMEM);
+	}
+	keymap_data->keymap = keymap;
+
+	for_each_child_of_node(np, key_np) {
+		u32 row, col, key_code;
+		of_property_read_u32(key_np, "keypad,row", &row);
+		of_property_read_u32(key_np, "keypad,column", &col);
+		of_property_read_u32(key_np, "linux,code", &key_code);
+		*keymap++ = KEY(row, col, key_code);
+	}
+
+	pdata->no_autorepeat = of_property_read_bool(np, "linux,input-no-autorepeat");
+
+	pdata->wakeup = of_property_read_bool(np, "wakeup-source") ||
+			/* legacy name */
+			of_property_read_bool(np, "linux,input-wakeup");
+
+
+	return pdata;
+}
+#else
+static struct samsung_keypad_platdata *
+samsung_keypad_parse_dt(struct device *dev)
+{
+	dev_err(dev, "no platform data defined\n");
+
+	return ERR_PTR(-EINVAL);
+}
+#endif
+
+static int samsung_keypad_probe(struct platform_device *pdev)
+{
+	const struct samsung_keypad_platdata *pdata;
+	const struct matrix_keymap_data *keymap_data;
+	const struct platform_device_id *id;
+	struct samsung_keypad *keypad;
+	struct resource *res;
+	struct input_dev *input_dev;
+	unsigned int row_shift;
+	int error;
+
+	pdata = dev_get_platdata(&pdev->dev);
+	if (!pdata) {
+		pdata = samsung_keypad_parse_dt(&pdev->dev);
+		if (IS_ERR(pdata))
+			return PTR_ERR(pdata);
+	}
+
+	keymap_data = pdata->keymap_data;
+	if (!keymap_data) {
+		dev_err(&pdev->dev, "no keymap data defined\n");
+		return -EINVAL;
+	}
+
+	if (!pdata->rows || pdata->rows > SAMSUNG_MAX_ROWS)
+		return -EINVAL;
+
+	if (!pdata->cols || pdata->cols > SAMSUNG_MAX_COLS)
+		return -EINVAL;
+
+	/* initialize the gpio */
+	if (pdata->cfg_gpio)
+		pdata->cfg_gpio(pdata->rows, pdata->cols);
+
+	row_shift = get_count_order(pdata->cols);
+
+	keypad = devm_kzalloc(&pdev->dev,
+			      struct_size(keypad, keycodes,
+					  pdata->rows << row_shift),
+			      GFP_KERNEL);
+	if (!keypad)
+		return -ENOMEM;
+
+	input_dev = devm_input_allocate_device(&pdev->dev);
+	if (!input_dev)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	if (!res)
+		return -ENODEV;
+
+	keypad->base = devm_ioremap(&pdev->dev, res->start, resource_size(res));
+	if (!keypad->base)
+		return -EBUSY;
+
+	keypad->clk = devm_clk_get_prepared(&pdev->dev, "keypad");
+	if (IS_ERR(keypad->clk)) {
+		dev_err(&pdev->dev, "failed to get keypad clk\n");
+		return PTR_ERR(keypad->clk);
+	}
+
+	keypad->input_dev = input_dev;
+	keypad->pdev = pdev;
+	keypad->row_shift = row_shift;
+	keypad->rows = pdata->rows;
+	keypad->cols = pdata->cols;
+	keypad->stopped = true;
+	init_waitqueue_head(&keypad->wait);
+
+	keypad->chip = device_get_match_data(&pdev->dev);
+	if (!keypad->chip) {
+		id = platform_get_device_id(pdev);
+		if (id)
+			keypad->chip = (const void *)id->driver_data;
+	}
+
+	if (!keypad->chip) {
+		dev_err(&pdev->dev, "Unable to determine chip type");
+		return -EINVAL;
+	}
+
+	input_dev->name = pdev->name;
+	input_dev->id.bustype = BUS_HOST;
+
+	input_dev->open = samsung_keypad_open;
+	input_dev->close = samsung_keypad_close;
+
+	error = matrix_keypad_build_keymap(keymap_data, NULL,
+					   pdata->rows, pdata->cols,
+					   keypad->keycodes, input_dev);
+	if (error) {
+		dev_err(&pdev->dev, "failed to build keymap\n");
+		return error;
+	}
+
+	input_set_capability(input_dev, EV_MSC, MSC_SCAN);
+	if (!pdata->no_autorepeat)
+		__set_bit(EV_REP, input_dev->evbit);
+
+	input_set_drvdata(input_dev, keypad);
+
+	keypad->irq = platform_get_irq(pdev, 0);
+	if (keypad->irq < 0) {
+		error = keypad->irq;
+		return error;
+	}
+
+	error = devm_request_threaded_irq(&pdev->dev, keypad->irq, NULL,
+					  samsung_keypad_irq,
+					  IRQF_ONESHOT | IRQF_NO_AUTOEN,
+					  dev_name(&pdev->dev), keypad);
+	if (error) {
+		dev_err(&pdev->dev, "failed to register keypad interrupt\n");
+		return error;
+	}
+
+	device_init_wakeup(&pdev->dev, pdata->wakeup);
+	platform_set_drvdata(pdev, keypad);
+
+	error = devm_pm_runtime_enable(&pdev->dev);
+	if (error)
+		return error;
+
+	error = input_register_device(keypad->input_dev);
+	if (error)
+		return error;
+
+	if (pdev->dev.of_node) {
+		devm_kfree(&pdev->dev, (void *)pdata->keymap_data->keymap);
+		devm_kfree(&pdev->dev, (void *)pdata->keymap_data);
+		devm_kfree(&pdev->dev, (void *)pdata);
+	}
+	return 0;
+}
+
+static int samsung_keypad_runtime_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct samsung_keypad *keypad = platform_get_drvdata(pdev);
+	unsigned int val;
+	int error;
+
+	if (keypad->stopped)
+		return 0;
+
+	/* This may fail on some SoCs due to lack of controller support */
+	error = enable_irq_wake(keypad->irq);
+	if (!error)
+		keypad->wake_enabled = true;
+
+	val = readl(keypad->base + SAMSUNG_KEYIFCON);
+	val |= SAMSUNG_KEYIFCON_WAKEUPEN;
+	writel(val, keypad->base + SAMSUNG_KEYIFCON);
+
+	clk_disable(keypad->clk);
+
+	return 0;
+}
+
+static int samsung_keypad_runtime_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct samsung_keypad *keypad = platform_get_drvdata(pdev);
+	unsigned int val;
+
+	if (keypad->stopped)
+		return 0;
+
+	clk_enable(keypad->clk);
+
+	val = readl(keypad->base + SAMSUNG_KEYIFCON);
+	val &= ~SAMSUNG_KEYIFCON_WAKEUPEN;
+	writel(val, keypad->base + SAMSUNG_KEYIFCON);
+
+	if (keypad->wake_enabled)
+		disable_irq_wake(keypad->irq);
+
+	return 0;
+}
+
+static void samsung_keypad_toggle_wakeup(struct samsung_keypad *keypad,
+					 bool enable)
+{
+	unsigned int val;
+
+	clk_enable(keypad->clk);
+
+	val = readl(keypad->base + SAMSUNG_KEYIFCON);
+	if (enable) {
+		enable_irq_wake(keypad->irq);
+		val |= SAMSUNG_KEYIFCON_WAKEUPEN;
+		writel(val, keypad->base + SAMSUNG_KEYIFCON);
+	} else {
+		val &= ~SAMSUNG_KEYIFCON_WAKEUPEN;
+		writel(val, keypad->base + SAMSUNG_KEYIFCON);
+		disable_irq_wake(keypad->irq);
+
+		if (!input_device_enabled(keypad->input_dev))
+			writel(~0x0, keypad->base + SAMSUNG_KEYIFSTSCLR);
+	}
+
+	clk_disable(keypad->clk);
+}
+
+static int samsung_keypad_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct samsung_keypad *keypad = platform_get_drvdata(pdev);
+	struct input_dev *input_dev = keypad->input_dev;
+
+	guard(mutex)(&input_dev->mutex);
+
+	if (input_device_enabled(input_dev))
+		samsung_keypad_stop(keypad);
+
+	if (device_may_wakeup(dev))
+		samsung_keypad_toggle_wakeup(keypad, true);
+
+	return 0;
+}
+
+static int samsung_keypad_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct samsung_keypad *keypad = platform_get_drvdata(pdev);
+	struct input_dev *input_dev = keypad->input_dev;
+
+	guard(mutex)(&input_dev->mutex);
+
+	if (device_may_wakeup(dev))
+		samsung_keypad_toggle_wakeup(keypad, false);
+
+	if (input_device_enabled(input_dev))
+		samsung_keypad_start(keypad);
+
+	return 0;
+}
+
+static const struct dev_pm_ops samsung_keypad_pm_ops = {
+	SYSTEM_SLEEP_PM_OPS(samsung_keypad_suspend, samsung_keypad_resume)
+	RUNTIME_PM_OPS(samsung_keypad_runtime_suspend,
+		       samsung_keypad_runtime_resume, NULL)
+};
+
+static const struct samsung_chip_info samsung_s3c6410_chip_info = {
+	.column_shift = 0,
+};
+
+static const struct samsung_chip_info samsung_s5pv210_chip_info = {
+	.column_shift = 8,
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id samsung_keypad_dt_match[] = {
+	{
+		.compatible = "samsung,s3c6410-keypad",
+		.data = &samsung_s3c6410_chip_info,
+	}, {
+		.compatible = "samsung,s5pv210-keypad",
+		.data = &samsung_s5pv210_chip_info,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, samsung_keypad_dt_match);
+#endif
+
+static const struct platform_device_id samsung_keypad_driver_ids[] = {
+	{
+		.name		= "samsung-keypad",
+		.driver_data	= (kernel_ulong_t)&samsung_s3c6410_chip_info,
+	}, {
+		.name		= "s5pv210-keypad",
+		.driver_data	= (kernel_ulong_t)&samsung_s5pv210_chip_info,
+	},
+	{ }
+};
+MODULE_DEVICE_TABLE(platform, samsung_keypad_driver_ids);
+
+static struct platform_driver samsung_keypad_driver = {
+	.probe		= samsung_keypad_probe,
+	.driver		= {
+		.name	= "samsung-keypad",
+		.of_match_table = of_match_ptr(samsung_keypad_dt_match),
+		.pm	= pm_ptr(&samsung_keypad_pm_ops),
+	},
+	.id_table	= samsung_keypad_driver_ids,
+};
+module_platform_driver(samsung_keypad_driver);
+
+MODULE_DESCRIPTION("Samsung keypad driver");
+MODULE_AUTHOR("Joonyoung Shim <jy0922.shim@samsung.com>");
+MODULE_AUTHOR("Donghwa Lee <dh09.lee@samsung.com>");
+MODULE_LICENSE("GPL");