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, 368 insertions, 0 deletions

diff --git a/drivers/mfd/max77693.c b/drivers/mfd/max77693.c
new file mode 100644
index 000000000..1c485a4c3
--- /dev/null
+++ b/drivers/mfd/max77693.c
@@ -0,0 +1,368 @@
+// SPDX-License-Identifier: GPL-2.0+
+//
+// max77693.c - mfd core driver for the MAX 77693
+//
+// Copyright (C) 2012 Samsung Electronics
+// SangYoung Son <hello.son@samsung.com>
+//
+// This program is not provided / owned by Maxim Integrated Products.
+//
+// This driver is based on max8997.c
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/i2c.h>
+#include <linux/err.h>
+#include <linux/interrupt.h>
+#include <linux/of.h>
+#include <linux/pm_runtime.h>
+#include <linux/mutex.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/max77693.h>
+#include <linux/mfd/max77693-common.h>
+#include <linux/mfd/max77693-private.h>
+#include <linux/regulator/machine.h>
+#include <linux/regmap.h>
+
+#define I2C_ADDR_PMIC	(0xCC >> 1)	/* Charger, Flash LED */
+#define I2C_ADDR_MUIC	(0x4A >> 1)
+#define I2C_ADDR_HAPTIC	(0x90 >> 1)
+
+static const struct mfd_cell max77693_devs[] = {
+	{ .name = "max77693-pmic", },
+	{
+		.name = "max77693-charger",
+		.of_compatible = "maxim,max77693-charger",
+	},
+	{
+		.name = "max77693-muic",
+		.of_compatible = "maxim,max77693-muic",
+	},
+	{
+		.name = "max77693-haptic",
+		.of_compatible = "maxim,max77693-haptic",
+	},
+	{
+		.name = "max77693-led",
+		.of_compatible = "maxim,max77693-led",
+	},
+};
+
+static const struct regmap_config max77693_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = MAX77693_PMIC_REG_END,
+};
+
+static const struct regmap_irq max77693_led_irqs[] = {
+	{ .mask = LED_IRQ_FLED2_OPEN,  },
+	{ .mask = LED_IRQ_FLED2_SHORT, },
+	{ .mask = LED_IRQ_FLED1_OPEN,  },
+	{ .mask = LED_IRQ_FLED1_SHORT, },
+	{ .mask = LED_IRQ_MAX_FLASH,   },
+};
+
+static const struct regmap_irq_chip max77693_led_irq_chip = {
+	.name			= "max77693-led",
+	.status_base		= MAX77693_LED_REG_FLASH_INT,
+	.mask_base		= MAX77693_LED_REG_FLASH_INT_MASK,
+	.num_regs		= 1,
+	.irqs			= max77693_led_irqs,
+	.num_irqs		= ARRAY_SIZE(max77693_led_irqs),
+};
+
+static const struct regmap_irq max77693_topsys_irqs[] = {
+	{ .mask = TOPSYS_IRQ_T120C_INT,  },
+	{ .mask = TOPSYS_IRQ_T140C_INT,  },
+	{ .mask = TOPSYS_IRQ_LOWSYS_INT, },
+};
+
+static const struct regmap_irq_chip max77693_topsys_irq_chip = {
+	.name			= "max77693-topsys",
+	.status_base		= MAX77693_PMIC_REG_TOPSYS_INT,
+	.mask_base		= MAX77693_PMIC_REG_TOPSYS_INT_MASK,
+	.num_regs		= 1,
+	.irqs			= max77693_topsys_irqs,
+	.num_irqs		= ARRAY_SIZE(max77693_topsys_irqs),
+};
+
+static const struct regmap_irq max77693_charger_irqs[] = {
+	{ .mask = CHG_IRQ_BYP_I,   },
+	{ .mask = CHG_IRQ_THM_I,   },
+	{ .mask = CHG_IRQ_BAT_I,   },
+	{ .mask = CHG_IRQ_CHG_I,   },
+	{ .mask = CHG_IRQ_CHGIN_I, },
+};
+
+static const struct regmap_irq_chip max77693_charger_irq_chip = {
+	.name			= "max77693-charger",
+	.status_base		= MAX77693_CHG_REG_CHG_INT,
+	.mask_base		= MAX77693_CHG_REG_CHG_INT_MASK,
+	.num_regs		= 1,
+	.irqs			= max77693_charger_irqs,
+	.num_irqs		= ARRAY_SIZE(max77693_charger_irqs),
+};
+
+static const struct regmap_config max77693_regmap_muic_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = MAX77693_MUIC_REG_END,
+};
+
+static const struct regmap_irq max77693_muic_irqs[] = {
+	{ .reg_offset = 0, .mask = MUIC_IRQ_INT1_ADC,		},
+	{ .reg_offset = 0, .mask = MUIC_IRQ_INT1_ADC_LOW,	},
+	{ .reg_offset = 0, .mask = MUIC_IRQ_INT1_ADC_ERR,	},
+	{ .reg_offset = 0, .mask = MUIC_IRQ_INT1_ADC1K,		},
+
+	{ .reg_offset = 1, .mask = MUIC_IRQ_INT2_CHGTYP,	},
+	{ .reg_offset = 1, .mask = MUIC_IRQ_INT2_CHGDETREUN,	},
+	{ .reg_offset = 1, .mask = MUIC_IRQ_INT2_DCDTMR,	},
+	{ .reg_offset = 1, .mask = MUIC_IRQ_INT2_DXOVP,		},
+	{ .reg_offset = 1, .mask = MUIC_IRQ_INT2_VBVOLT,	},
+	{ .reg_offset = 1, .mask = MUIC_IRQ_INT2_VIDRM,		},
+
+	{ .reg_offset = 2, .mask = MUIC_IRQ_INT3_EOC,		},
+	{ .reg_offset = 2, .mask = MUIC_IRQ_INT3_CGMBC,		},
+	{ .reg_offset = 2, .mask = MUIC_IRQ_INT3_OVP,		},
+	{ .reg_offset = 2, .mask = MUIC_IRQ_INT3_MBCCHG_ERR,	},
+	{ .reg_offset = 2, .mask = MUIC_IRQ_INT3_CHG_ENABLED,	},
+	{ .reg_offset = 2, .mask = MUIC_IRQ_INT3_BAT_DET,	},
+};
+
+static const struct regmap_irq_chip max77693_muic_irq_chip = {
+	.name			= "max77693-muic",
+	.status_base		= MAX77693_MUIC_REG_INT1,
+	.unmask_base		= MAX77693_MUIC_REG_INTMASK1,
+	.num_regs		= 3,
+	.irqs			= max77693_muic_irqs,
+	.num_irqs		= ARRAY_SIZE(max77693_muic_irqs),
+};
+
+static const struct regmap_config max77693_regmap_haptic_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = MAX77693_HAPTIC_REG_END,
+};
+
+static int max77693_i2c_probe(struct i2c_client *i2c)
+{
+	const struct i2c_device_id *id = i2c_client_get_device_id(i2c);
+	struct max77693_dev *max77693;
+	unsigned int reg_data;
+	int ret = 0;
+
+	max77693 = devm_kzalloc(&i2c->dev,
+			sizeof(struct max77693_dev), GFP_KERNEL);
+	if (max77693 == NULL)
+		return -ENOMEM;
+
+	i2c_set_clientdata(i2c, max77693);
+	max77693->dev = &i2c->dev;
+	max77693->i2c = i2c;
+	max77693->irq = i2c->irq;
+	max77693->type = id->driver_data;
+
+	max77693->regmap = devm_regmap_init_i2c(i2c, &max77693_regmap_config);
+	if (IS_ERR(max77693->regmap)) {
+		ret = PTR_ERR(max77693->regmap);
+		dev_err(max77693->dev, "failed to allocate register map: %d\n",
+				ret);
+		return ret;
+	}
+
+	ret = regmap_read(max77693->regmap, MAX77693_PMIC_REG_PMIC_ID2,
+				&reg_data);
+	if (ret < 0) {
+		dev_err(max77693->dev, "device not found on this channel\n");
+		return ret;
+	} else
+		dev_info(max77693->dev, "device ID: 0x%x\n", reg_data);
+
+	max77693->i2c_muic = i2c_new_dummy_device(i2c->adapter, I2C_ADDR_MUIC);
+	if (IS_ERR(max77693->i2c_muic)) {
+		dev_err(max77693->dev, "Failed to allocate I2C device for MUIC\n");
+		return PTR_ERR(max77693->i2c_muic);
+	}
+	i2c_set_clientdata(max77693->i2c_muic, max77693);
+
+	max77693->i2c_haptic = i2c_new_dummy_device(i2c->adapter, I2C_ADDR_HAPTIC);
+	if (IS_ERR(max77693->i2c_haptic)) {
+		dev_err(max77693->dev, "Failed to allocate I2C device for Haptic\n");
+		ret = PTR_ERR(max77693->i2c_haptic);
+		goto err_i2c_haptic;
+	}
+	i2c_set_clientdata(max77693->i2c_haptic, max77693);
+
+	max77693->regmap_haptic = devm_regmap_init_i2c(max77693->i2c_haptic,
+					&max77693_regmap_haptic_config);
+	if (IS_ERR(max77693->regmap_haptic)) {
+		ret = PTR_ERR(max77693->regmap_haptic);
+		dev_err(max77693->dev,
+			"failed to initialize haptic register map: %d\n", ret);
+		goto err_regmap;
+	}
+
+	/*
+	 * Initialize register map for MUIC device because use regmap-muic
+	 * instance of MUIC device when irq of max77693 is initialized
+	 * before call max77693-muic probe() function.
+	 */
+	max77693->regmap_muic = devm_regmap_init_i2c(max77693->i2c_muic,
+					 &max77693_regmap_muic_config);
+	if (IS_ERR(max77693->regmap_muic)) {
+		ret = PTR_ERR(max77693->regmap_muic);
+		dev_err(max77693->dev,
+			"failed to allocate register map: %d\n", ret);
+		goto err_regmap;
+	}
+
+	ret = regmap_add_irq_chip(max77693->regmap, max77693->irq,
+				IRQF_ONESHOT | IRQF_SHARED, 0,
+				&max77693_led_irq_chip,
+				&max77693->irq_data_led);
+	if (ret) {
+		dev_err(max77693->dev, "failed to add irq chip: %d\n", ret);
+		goto err_regmap;
+	}
+
+	ret = regmap_add_irq_chip(max77693->regmap, max77693->irq,
+				IRQF_ONESHOT | IRQF_SHARED, 0,
+				&max77693_topsys_irq_chip,
+				&max77693->irq_data_topsys);
+	if (ret) {
+		dev_err(max77693->dev, "failed to add irq chip: %d\n", ret);
+		goto err_irq_topsys;
+	}
+
+	ret = regmap_add_irq_chip(max77693->regmap, max77693->irq,
+				IRQF_ONESHOT | IRQF_SHARED, 0,
+				&max77693_charger_irq_chip,
+				&max77693->irq_data_chg);
+	if (ret) {
+		dev_err(max77693->dev, "failed to add irq chip: %d\n", ret);
+		goto err_irq_charger;
+	}
+
+	ret = regmap_add_irq_chip(max77693->regmap_muic, max77693->irq,
+				IRQF_ONESHOT | IRQF_SHARED, 0,
+				&max77693_muic_irq_chip,
+				&max77693->irq_data_muic);
+	if (ret) {
+		dev_err(max77693->dev, "failed to add irq chip: %d\n", ret);
+		goto err_irq_muic;
+	}
+
+	/* Unmask interrupts from all blocks in interrupt source register */
+	ret = regmap_update_bits(max77693->regmap,
+				MAX77693_PMIC_REG_INTSRC_MASK,
+				SRC_IRQ_ALL, (unsigned int)~SRC_IRQ_ALL);
+	if (ret < 0) {
+		dev_err(max77693->dev,
+			"Could not unmask interrupts in INTSRC: %d\n",
+			ret);
+		goto err_intsrc;
+	}
+
+	pm_runtime_set_active(max77693->dev);
+
+	ret = mfd_add_devices(max77693->dev, -1, max77693_devs,
+			      ARRAY_SIZE(max77693_devs), NULL, 0, NULL);
+	if (ret < 0)
+		goto err_mfd;
+
+	return ret;
+
+err_mfd:
+	mfd_remove_devices(max77693->dev);
+err_intsrc:
+	regmap_del_irq_chip(max77693->irq, max77693->irq_data_muic);
+err_irq_muic:
+	regmap_del_irq_chip(max77693->irq, max77693->irq_data_chg);
+err_irq_charger:
+	regmap_del_irq_chip(max77693->irq, max77693->irq_data_topsys);
+err_irq_topsys:
+	regmap_del_irq_chip(max77693->irq, max77693->irq_data_led);
+err_regmap:
+	i2c_unregister_device(max77693->i2c_haptic);
+err_i2c_haptic:
+	i2c_unregister_device(max77693->i2c_muic);
+	return ret;
+}
+
+static void max77693_i2c_remove(struct i2c_client *i2c)
+{
+	struct max77693_dev *max77693 = i2c_get_clientdata(i2c);
+
+	mfd_remove_devices(max77693->dev);
+
+	regmap_del_irq_chip(max77693->irq, max77693->irq_data_muic);
+	regmap_del_irq_chip(max77693->irq, max77693->irq_data_chg);
+	regmap_del_irq_chip(max77693->irq, max77693->irq_data_topsys);
+	regmap_del_irq_chip(max77693->irq, max77693->irq_data_led);
+
+	i2c_unregister_device(max77693->i2c_muic);
+	i2c_unregister_device(max77693->i2c_haptic);
+}
+
+static const struct i2c_device_id max77693_i2c_id[] = {
+	{ "max77693", TYPE_MAX77693 },
+	{ }
+};
+MODULE_DEVICE_TABLE(i2c, max77693_i2c_id);
+
+static int max77693_suspend(struct device *dev)
+{
+	struct i2c_client *i2c = to_i2c_client(dev);
+	struct max77693_dev *max77693 = i2c_get_clientdata(i2c);
+
+	if (device_may_wakeup(dev)) {
+		enable_irq_wake(max77693->irq);
+		disable_irq(max77693->irq);
+	}
+
+	return 0;
+}
+
+static int max77693_resume(struct device *dev)
+{
+	struct i2c_client *i2c = to_i2c_client(dev);
+	struct max77693_dev *max77693 = i2c_get_clientdata(i2c);
+
+	if (device_may_wakeup(dev)) {
+		disable_irq_wake(max77693->irq);
+		enable_irq(max77693->irq);
+	}
+
+	return 0;
+}
+
+static const struct dev_pm_ops max77693_pm = {
+	.suspend = max77693_suspend,
+	.resume = max77693_resume,
+};
+
+#ifdef CONFIG_OF
+static const struct of_device_id max77693_dt_match[] = {
+	{ .compatible = "maxim,max77693" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, max77693_dt_match);
+#endif
+
+static struct i2c_driver max77693_i2c_driver = {
+	.driver = {
+		   .name = "max77693",
+		   .pm = &max77693_pm,
+		   .of_match_table = of_match_ptr(max77693_dt_match),
+	},
+	.probe = max77693_i2c_probe,
+	.remove = max77693_i2c_remove,
+	.id_table = max77693_i2c_id,
+};
+
+module_i2c_driver(max77693_i2c_driver);
+
+MODULE_DESCRIPTION("MAXIM 77693 multi-function core driver");
+MODULE_AUTHOR("SangYoung, Son <hello.son@samsung.com>");
+MODULE_LICENSE("GPL");