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, 275 insertions, 0 deletions

diff --git a/drivers/mfd/88pm805.c b/drivers/mfd/88pm805.c
new file mode 100644
index 000000000..f5d666317
--- /dev/null
+++ b/drivers/mfd/88pm805.c
@@ -0,0 +1,275 @@
+/*
+ * Base driver for Marvell 88PM805
+ *
+ * Copyright (C) 2012 Marvell International Ltd.
+ * Haojian Zhuang <haojian.zhuang@marvell.com>
+ * Joseph(Yossi) Hanin <yhanin@marvell.com>
+ * Qiao Zhou <zhouqiao@marvell.com>
+ *
+ * This file is subject to the terms and conditions of the GNU General
+ * Public License. See the file "COPYING" in the main directory of this
+ * archive for more details.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/i2c.h>
+#include <linux/irq.h>
+#include <linux/mfd/core.h>
+#include <linux/mfd/88pm80x.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+
+static const struct i2c_device_id pm80x_id_table[] = {
+	{ "88PM805" },
+	{} /* NULL terminated */
+};
+MODULE_DEVICE_TABLE(i2c, pm80x_id_table);
+
+/* Interrupt Number in 88PM805 */
+enum {
+	PM805_IRQ_LDO_OFF,	/*0 */
+	PM805_IRQ_SRC_DPLL_LOCK,	/*1 */
+	PM805_IRQ_CLIP_FAULT,
+	PM805_IRQ_MIC_CONFLICT,
+	PM805_IRQ_HP2_SHRT,
+	PM805_IRQ_HP1_SHRT,	/*5 */
+	PM805_IRQ_FINE_PLL_FAULT,
+	PM805_IRQ_RAW_PLL_FAULT,
+	PM805_IRQ_VOLP_BTN_DET,
+	PM805_IRQ_VOLM_BTN_DET,
+	PM805_IRQ_SHRT_BTN_DET,	/*10 */
+	PM805_IRQ_MIC_DET,	/*11 */
+
+	PM805_MAX_IRQ,
+};
+
+static struct resource codec_resources[] = {
+	/* Headset microphone insertion or removal */
+	DEFINE_RES_IRQ_NAMED(PM805_IRQ_MIC_DET, "micin"),
+
+	/* Audio short HP1 */
+	DEFINE_RES_IRQ_NAMED(PM805_IRQ_HP1_SHRT, "audio-short1"),
+
+	/* Audio short HP2 */
+	DEFINE_RES_IRQ_NAMED(PM805_IRQ_HP2_SHRT, "audio-short2"),
+};
+
+static const struct mfd_cell codec_devs[] = {
+	{
+	 .name = "88pm80x-codec",
+	 .num_resources = ARRAY_SIZE(codec_resources),
+	 .resources = &codec_resources[0],
+	 .id = -1,
+	 },
+};
+
+static const struct regmap_irq pm805_irqs[] = {
+	/* INT0 */
+	[PM805_IRQ_LDO_OFF] = {
+		.mask = PM805_INT1_HP1_SHRT,
+	},
+	[PM805_IRQ_SRC_DPLL_LOCK] = {
+		.mask = PM805_INT1_HP2_SHRT,
+	},
+	[PM805_IRQ_CLIP_FAULT] = {
+		.mask = PM805_INT1_MIC_CONFLICT,
+	},
+	[PM805_IRQ_MIC_CONFLICT] = {
+		.mask = PM805_INT1_CLIP_FAULT,
+	},
+	[PM805_IRQ_HP2_SHRT] = {
+		.mask = PM805_INT1_LDO_OFF,
+	},
+	[PM805_IRQ_HP1_SHRT] = {
+		.mask = PM805_INT1_SRC_DPLL_LOCK,
+	},
+	/* INT1 */
+	[PM805_IRQ_FINE_PLL_FAULT] = {
+		.reg_offset = 1,
+		.mask = PM805_INT2_MIC_DET,
+	},
+	[PM805_IRQ_RAW_PLL_FAULT] = {
+		.reg_offset = 1,
+		.mask = PM805_INT2_SHRT_BTN_DET,
+	},
+	[PM805_IRQ_VOLP_BTN_DET] = {
+		.reg_offset = 1,
+		.mask = PM805_INT2_VOLM_BTN_DET,
+	},
+	[PM805_IRQ_VOLM_BTN_DET] = {
+		.reg_offset = 1,
+		.mask = PM805_INT2_VOLP_BTN_DET,
+	},
+	[PM805_IRQ_SHRT_BTN_DET] = {
+		.reg_offset = 1,
+		.mask = PM805_INT2_RAW_PLL_FAULT,
+	},
+	[PM805_IRQ_MIC_DET] = {
+		.reg_offset = 1,
+		.mask = PM805_INT2_FINE_PLL_FAULT,
+	},
+};
+
+static int device_irq_init_805(struct pm80x_chip *chip)
+{
+	struct regmap *map = chip->regmap;
+	unsigned long flags = IRQF_ONESHOT;
+	int data, mask, ret = -EINVAL;
+
+	if (!map || !chip->irq) {
+		dev_err(chip->dev, "incorrect parameters\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * irq_mode defines the way of clearing interrupt. it's read-clear by
+	 * default.
+	 */
+	mask =
+	    PM805_STATUS0_INT_CLEAR | PM805_STATUS0_INV_INT |
+	    PM800_STATUS0_INT_MASK;
+
+	data = PM805_STATUS0_INT_CLEAR;
+	ret = regmap_update_bits(map, PM805_INT_STATUS0, mask, data);
+	/*
+	 * PM805_INT_STATUS is under 32K clock domain, so need to
+	 * add proper delay before the next I2C register access.
+	 */
+	usleep_range(1000, 3000);
+
+	if (ret < 0)
+		goto out;
+
+	ret =
+	    regmap_add_irq_chip(chip->regmap, chip->irq, flags, -1,
+				chip->regmap_irq_chip, &chip->irq_data);
+
+out:
+	return ret;
+}
+
+static void device_irq_exit_805(struct pm80x_chip *chip)
+{
+	regmap_del_irq_chip(chip->irq, chip->irq_data);
+}
+
+static const struct regmap_irq_chip pm805_irq_chip = {
+	.name = "88pm805",
+	.irqs = pm805_irqs,
+	.num_irqs = ARRAY_SIZE(pm805_irqs),
+
+	.num_regs = 2,
+	.status_base = PM805_INT_STATUS1,
+	.mask_base = PM805_INT_MASK1,
+	.ack_base = PM805_INT_STATUS1,
+};
+
+static int device_805_init(struct pm80x_chip *chip)
+{
+	int ret = 0;
+	struct regmap *map = chip->regmap;
+
+	if (!map) {
+		dev_err(chip->dev, "regmap is invalid\n");
+		return -EINVAL;
+	}
+
+	chip->regmap_irq_chip = &pm805_irq_chip;
+
+	ret = device_irq_init_805(chip);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to init pm805 irq!\n");
+		goto out_irq_init;
+	}
+
+	ret = mfd_add_devices(chip->dev, 0, &codec_devs[0],
+			      ARRAY_SIZE(codec_devs), &codec_resources[0], 0,
+			      NULL);
+	if (ret < 0) {
+		dev_err(chip->dev, "Failed to add codec subdev\n");
+		goto out_codec;
+	} else
+		dev_info(chip->dev, "[%s]:Added mfd codec_devs\n", __func__);
+
+	return 0;
+
+out_codec:
+	device_irq_exit_805(chip);
+out_irq_init:
+	return ret;
+}
+
+static int pm805_probe(struct i2c_client *client)
+{
+	int ret = 0;
+	struct pm80x_chip *chip;
+	struct pm80x_platform_data *pdata = dev_get_platdata(&client->dev);
+
+	ret = pm80x_init(client);
+	if (ret) {
+		dev_err(&client->dev, "pm805_init fail!\n");
+		goto out_init;
+	}
+
+	chip = i2c_get_clientdata(client);
+
+	ret = device_805_init(chip);
+	if (ret) {
+		dev_err(chip->dev, "Failed to initialize 88pm805 devices\n");
+		goto err_805_init;
+	}
+
+	if (pdata && pdata->plat_config)
+		pdata->plat_config(chip, pdata);
+
+err_805_init:
+	pm80x_deinit();
+out_init:
+	return ret;
+}
+
+static void pm805_remove(struct i2c_client *client)
+{
+	struct pm80x_chip *chip = i2c_get_clientdata(client);
+
+	mfd_remove_devices(chip->dev);
+	device_irq_exit_805(chip);
+
+	pm80x_deinit();
+}
+
+static struct i2c_driver pm805_driver = {
+	.driver = {
+		.name = "88PM805",
+		.pm = pm_sleep_ptr(&pm80x_pm_ops),
+		},
+	.probe = pm805_probe,
+	.remove = pm805_remove,
+	.id_table = pm80x_id_table,
+};
+
+static int __init pm805_i2c_init(void)
+{
+	return i2c_add_driver(&pm805_driver);
+}
+subsys_initcall(pm805_i2c_init);
+
+static void __exit pm805_i2c_exit(void)
+{
+	i2c_del_driver(&pm805_driver);
+}
+module_exit(pm805_i2c_exit);
+
+MODULE_DESCRIPTION("PMIC Driver for Marvell 88PM805");
+MODULE_AUTHOR("Qiao Zhou <zhouqiao@marvell.com>");
+MODULE_LICENSE("GPL");