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, 251 insertions, 0 deletions

diff --git a/drivers/hid/hid-tmff.c b/drivers/hid/hid-tmff.c
new file mode 100644
index 000000000..303769b07
--- /dev/null
+++ b/drivers/hid/hid-tmff.c
@@ -0,0 +1,251 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Force feedback support for various HID compliant devices by ThrustMaster:
+ *    ThrustMaster FireStorm Dual Power 2
+ * and possibly others whose device ids haven't been added.
+ *
+ *  Modified to support ThrustMaster devices by Zinx Verituse
+ *  on 2003-01-25 from the Logitech force feedback driver,
+ *  which is by Johann Deneux.
+ *
+ *  Copyright (c) 2003 Zinx Verituse <zinx@epicsol.org>
+ *  Copyright (c) 2002 Johann Deneux
+ */
+
+/*
+ */
+
+#include <linux/hid.h>
+#include <linux/input.h>
+#include <linux/math64.h>
+#include <linux/slab.h>
+#include <linux/module.h>
+
+#include "hid-ids.h"
+
+#define THRUSTMASTER_DEVICE_ID_2_IN_1_DT	0xb320
+
+static const signed short ff_rumble[] = {
+	FF_RUMBLE,
+	-1
+};
+
+static const signed short ff_joystick[] = {
+	FF_CONSTANT,
+	-1
+};
+
+#ifdef CONFIG_THRUSTMASTER_FF
+
+/* Usages for thrustmaster devices I know about */
+#define THRUSTMASTER_USAGE_FF	(HID_UP_GENDESK | 0xbb)
+
+struct tmff_device {
+	struct hid_report *report;
+	struct hid_field *ff_field;
+};
+
+/* Changes values from 0 to 0xffff into values from minimum to maximum */
+static inline int tmff_scale_u16(unsigned int in, int minimum, int maximum)
+{
+	s64 ret;
+
+	ret = div_s64((s64)in * ((s64)maximum - minimum), 0xffff) + minimum;
+	if (ret < minimum)
+		return minimum;
+	if (ret > maximum)
+		return maximum;
+	return ret;
+}
+
+/* Changes values from -0x80 to 0x7f into values from minimum to maximum */
+static inline int tmff_scale_s8(int in, int minimum, int maximum)
+{
+	s64 ret;
+
+	ret = div_s64((s64)(in + 0x80) * ((s64)maximum - minimum), 0xff) + minimum;
+	if (ret < minimum)
+		return minimum;
+	if (ret > maximum)
+		return maximum;
+	return ret;
+}
+
+static int tmff_play(struct input_dev *dev, void *data,
+		struct ff_effect *effect)
+{
+	struct hid_device *hid = input_get_drvdata(dev);
+	struct tmff_device *tmff = data;
+	struct hid_field *ff_field = tmff->ff_field;
+	int x, y;
+	int left, right;	/* Rumbling */
+
+	switch (effect->type) {
+	case FF_CONSTANT:
+		x = tmff_scale_s8(effect->u.ramp.start_level,
+					ff_field->logical_minimum,
+					ff_field->logical_maximum);
+		y = tmff_scale_s8(effect->u.ramp.end_level,
+					ff_field->logical_minimum,
+					ff_field->logical_maximum);
+
+		dbg_hid("(x, y)=(%04x, %04x)\n", x, y);
+		ff_field->value[0] = x;
+		ff_field->value[1] = y;
+		hid_hw_request(hid, tmff->report, HID_REQ_SET_REPORT);
+		break;
+
+	case FF_RUMBLE:
+		left = tmff_scale_u16(effect->u.rumble.weak_magnitude,
+					ff_field->logical_minimum,
+					ff_field->logical_maximum);
+		right = tmff_scale_u16(effect->u.rumble.strong_magnitude,
+					ff_field->logical_minimum,
+					ff_field->logical_maximum);
+
+		/* 2-in-1 strong motor is left */
+		if (hid->product == THRUSTMASTER_DEVICE_ID_2_IN_1_DT)
+			swap(left, right);
+
+		dbg_hid("(left,right)=(%08x, %08x)\n", left, right);
+		ff_field->value[0] = left;
+		ff_field->value[1] = right;
+		hid_hw_request(hid, tmff->report, HID_REQ_SET_REPORT);
+		break;
+	}
+	return 0;
+}
+
+static int tm_input_configured(struct hid_device *hid, struct hid_input *hidinput)
+{
+	struct tmff_device *tmff;
+	struct hid_report *report;
+	struct list_head *report_list;
+	struct input_dev *input_dev = hidinput->input;
+	const struct hid_device_id *id;
+	const signed short *ff_bits;
+	int error;
+	int i;
+
+	if (!list_is_first(&hidinput->list, &hid->inputs))
+		return 0;
+
+	id = hid_match_device(hid, hid->driver);
+	if (!id)
+		return -ENODEV;
+
+	ff_bits = (void *)id->driver_data;
+
+	tmff = kzalloc_obj(struct tmff_device);
+	if (!tmff)
+		return -ENOMEM;
+
+	/* Find the report to use */
+	report_list = &hid->report_enum[HID_OUTPUT_REPORT].report_list;
+	list_for_each_entry(report, report_list, list) {
+		int fieldnum;
+
+		for (fieldnum = 0; fieldnum < report->maxfield; ++fieldnum) {
+			struct hid_field *field = report->field[fieldnum];
+
+			if (field->maxusage <= 0)
+				continue;
+
+			switch (field->usage[0].hid) {
+			case THRUSTMASTER_USAGE_FF:
+				if (field->report_count < 2) {
+					hid_warn(hid, "ignoring FF field with report_count < 2\n");
+					continue;
+				}
+
+				if (field->logical_maximum ==
+						field->logical_minimum) {
+					hid_warn(hid, "ignoring FF field with logical_maximum == logical_minimum\n");
+					continue;
+				}
+
+				if (tmff->report && tmff->report != report) {
+					hid_warn(hid, "ignoring FF field in other report\n");
+					continue;
+				}
+
+				if (tmff->ff_field && tmff->ff_field != field) {
+					hid_warn(hid, "ignoring duplicate FF field\n");
+					continue;
+				}
+
+				tmff->report = report;
+				tmff->ff_field = field;
+
+				for (i = 0; ff_bits[i] >= 0; i++)
+					set_bit(ff_bits[i], input_dev->ffbit);
+
+				break;
+
+			default:
+				hid_warn(hid, "ignoring unknown output usage %08x\n",
+					 field->usage[0].hid);
+				continue;
+			}
+		}
+	}
+
+	if (!tmff->report) {
+		hid_err(hid, "can't find FF field in output reports\n");
+		error = -ENODEV;
+		goto fail;
+	}
+
+	error = input_ff_create_memless(input_dev, tmff, tmff_play);
+	if (error)
+		goto fail;
+
+	hid_info(hid, "force feedback for ThrustMaster devices by Zinx Verituse <zinx@epicsol.org>\n");
+	return 0;
+
+fail:
+	kfree(tmff);
+	return error;
+}
+#else
+static inline int tm_input_configured(struct hid_device *hid,
+				      struct hid_input *hidinput)
+{
+	return 0;
+}
+#endif
+
+static const struct hid_device_id tm_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, 0xb300),
+		.driver_data = (unsigned long)ff_rumble },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, 0xb304),   /* FireStorm Dual Power 2 (and 3) */
+		.driver_data = (unsigned long)ff_rumble },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, THRUSTMASTER_DEVICE_ID_2_IN_1_DT),   /* Dual Trigger 2-in-1 */
+		.driver_data = (unsigned long)ff_rumble },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, 0xb323),   /* Dual Trigger 3-in-1 (PC Mode) */
+		.driver_data = (unsigned long)ff_rumble },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, 0xb324),   /* Dual Trigger 3-in-1 (PS3 Mode) */
+		.driver_data = (unsigned long)ff_rumble },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, 0xb605),   /* NASCAR PRO FF2 Wheel */
+		.driver_data = (unsigned long)ff_joystick },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, 0xb651),	/* FGT Rumble Force Wheel */
+		.driver_data = (unsigned long)ff_rumble },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, 0xb653),	/* RGT Force Feedback CLUTCH Raging Wheel */
+		.driver_data = (unsigned long)ff_joystick },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, 0xb654),	/* FGT Force Feedback Wheel */
+		.driver_data = (unsigned long)ff_joystick },
+	{ HID_USB_DEVICE(USB_VENDOR_ID_THRUSTMASTER, 0xb65a),	/* F430 Force Feedback Wheel */
+		.driver_data = (unsigned long)ff_joystick },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, tm_devices);
+
+static struct hid_driver tm_driver = {
+	.name = "thrustmaster",
+	.id_table = tm_devices,
+	.input_configured = tm_input_configured,
+};
+module_hid_driver(tm_driver);
+
+MODULE_DESCRIPTION("Force feedback support for various HID compliant devices by ThrustMaster");
+MODULE_LICENSE("GPL");