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, 250 insertions, 0 deletions

diff --git a/drivers/hid/hid-plantronics.c b/drivers/hid/hid-plantronics.c
new file mode 100644
index 000000000..acb9eb18f
--- /dev/null
+++ b/drivers/hid/hid-plantronics.c
@@ -0,0 +1,250 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ *  Plantronics USB HID Driver
+ *
+ *  Copyright (c) 2014 JD Cole <jd.cole@plantronics.com>
+ *  Copyright (c) 2015-2018 Terry Junge <terry.junge@plantronics.com>
+ */
+
+#include "hid-ids.h"
+
+#include <linux/hid.h>
+#include <linux/module.h>
+#include <linux/jiffies.h>
+
+#define PLT_HID_1_0_PAGE	0xffa00000
+#define PLT_HID_2_0_PAGE	0xffa20000
+
+#define PLT_BASIC_TELEPHONY	0x0003
+#define PLT_BASIC_EXCEPTION	0x0005
+
+#define PLT_VOL_UP		0x00b1
+#define PLT_VOL_DOWN		0x00b2
+#define PLT_MIC_MUTE		0x00b5
+
+#define PLT1_VOL_UP		(PLT_HID_1_0_PAGE | PLT_VOL_UP)
+#define PLT1_VOL_DOWN		(PLT_HID_1_0_PAGE | PLT_VOL_DOWN)
+#define PLT1_MIC_MUTE		(PLT_HID_1_0_PAGE | PLT_MIC_MUTE)
+#define PLT2_VOL_UP		(PLT_HID_2_0_PAGE | PLT_VOL_UP)
+#define PLT2_VOL_DOWN		(PLT_HID_2_0_PAGE | PLT_VOL_DOWN)
+#define PLT2_MIC_MUTE		(PLT_HID_2_0_PAGE | PLT_MIC_MUTE)
+#define HID_TELEPHONY_MUTE	(HID_UP_TELEPHONY | 0x2f)
+#define HID_CONSUMER_MUTE	(HID_UP_CONSUMER | 0xe2)
+
+#define PLT_DA60		0xda60
+#define PLT_BT300_MIN		0x0413
+#define PLT_BT300_MAX		0x0418
+
+#define PLT_DOUBLE_KEY_TIMEOUT 5 /* ms */
+
+struct plt_drv_data {
+	unsigned long device_type;
+	unsigned long last_key_ts;
+	unsigned long double_key_to;
+	__u16 last_key;
+};
+
+static int plantronics_input_mapping(struct hid_device *hdev,
+				     struct hid_input *hi,
+				     struct hid_field *field,
+				     struct hid_usage *usage,
+				     unsigned long **bit, int *max)
+{
+	unsigned short mapped_key;
+	struct plt_drv_data *drv_data = hid_get_drvdata(hdev);
+	unsigned long plt_type = drv_data->device_type;
+	int allow_mute = usage->hid == HID_TELEPHONY_MUTE;
+	int allow_consumer = field->application == HID_CP_CONSUMERCONTROL &&
+			(usage->hid & HID_USAGE_PAGE) == HID_UP_CONSUMER &&
+			usage->hid != HID_CONSUMER_MUTE;
+
+	/* special case for PTT products */
+	if (field->application == HID_GD_JOYSTICK)
+		goto defaulted;
+
+	/* non-standard types or multi-HID interfaces - plt_type is PID */
+	if (!(plt_type & HID_USAGE_PAGE)) {
+		switch (plt_type) {
+		case PLT_DA60:
+			if (allow_consumer)
+				goto defaulted;
+			if (usage->hid == HID_CONSUMER_MUTE) {
+				mapped_key = KEY_MICMUTE;
+				goto mapped;
+			}
+			break;
+		default:
+			if (allow_consumer || allow_mute)
+				goto defaulted;
+		}
+		goto ignored;
+	}
+
+	/* handle standard consumer control mapping */
+	/* and standard telephony mic mute mapping */
+	if (allow_consumer || allow_mute)
+		goto defaulted;
+
+	/* handle vendor unique types - plt_type is 0xffa0uuuu or 0xffa2uuuu */
+	/* if not 'basic telephony compliant' - map vendor unique controls */
+	if (!((plt_type & HID_USAGE) >= PLT_BASIC_TELEPHONY &&
+	      (plt_type & HID_USAGE) != PLT_BASIC_EXCEPTION) &&
+	      !((field->application ^ plt_type) & HID_USAGE_PAGE))
+		switch (usage->hid) {
+		case PLT1_VOL_UP:
+		case PLT2_VOL_UP:
+			mapped_key = KEY_VOLUMEUP;
+			goto mapped;
+		case PLT1_VOL_DOWN:
+		case PLT2_VOL_DOWN:
+			mapped_key = KEY_VOLUMEDOWN;
+			goto mapped;
+		case PLT1_MIC_MUTE:
+		case PLT2_MIC_MUTE:
+			mapped_key = KEY_MICMUTE;
+			goto mapped;
+		}
+
+/*
+ * Future mapping of call control or other usages,
+ * if and when keys are defined would go here
+ * otherwise, ignore everything else that was not mapped
+ */
+
+ignored:
+	hid_dbg(hdev, "usage: %08x (appl: %08x) - ignored\n",
+		usage->hid, field->application);
+	return -1;
+
+defaulted:
+	hid_dbg(hdev, "usage: %08x (appl: %08x) - defaulted\n",
+		usage->hid, field->application);
+	return 0;
+
+mapped:
+	hid_map_usage_clear(hi, usage, bit, max, EV_KEY, mapped_key);
+	hid_dbg(hdev, "usage: %08x (appl: %08x) - mapped to key %d\n",
+		usage->hid, field->application, mapped_key);
+	return 1;
+}
+
+static int plantronics_event(struct hid_device *hdev, struct hid_field *field,
+			     struct hid_usage *usage, __s32 value)
+{
+	struct plt_drv_data *drv_data = hid_get_drvdata(hdev);
+	unsigned long prev_tsto, cur_ts;
+	__u16 prev_key, cur_key;
+
+	/* Usages are filtered in plantronics_usages. */
+
+	/* HZ too low for ms resolution - double key detection disabled */
+	/* or it is a key release - handle key presses only. */
+	if (!drv_data->double_key_to || !value)
+		return 0;
+
+	prev_tsto = drv_data->last_key_ts + drv_data->double_key_to;
+	cur_ts = drv_data->last_key_ts = jiffies;
+	prev_key = drv_data->last_key;
+	cur_key = drv_data->last_key = usage->code;
+
+	/* If the same key occurs in <= double_key_to -- ignore it */
+	if (prev_key == cur_key && time_before_eq(cur_ts, prev_tsto)) {
+		hid_dbg(hdev, "double key %d ignored\n", cur_key);
+		return 1; /* Ignore the repeated key. */
+	}
+	return 0;
+}
+
+static unsigned long plantronics_device_type(struct hid_device *hdev)
+{
+	unsigned i, col_page;
+	unsigned long plt_type = hdev->product;
+
+	/* multi-HID interfaces? - plt_type is PID */
+	if (plt_type >= PLT_BT300_MIN && plt_type <= PLT_BT300_MAX)
+		goto exit;
+
+	/* determine primary vendor page */
+	for (i = 0; i < hdev->maxcollection; i++) {
+		col_page = hdev->collection[i].usage & HID_USAGE_PAGE;
+		if (col_page == PLT_HID_2_0_PAGE) {
+			plt_type = hdev->collection[i].usage;
+			break;
+		}
+		if (col_page == PLT_HID_1_0_PAGE)
+			plt_type = hdev->collection[i].usage;
+	}
+
+exit:
+	hid_dbg(hdev, "plt_type decoded as: %08lx\n", plt_type);
+	return plt_type;
+}
+
+static int plantronics_probe(struct hid_device *hdev,
+			     const struct hid_device_id *id)
+{
+	struct plt_drv_data *drv_data;
+	int ret;
+
+	drv_data = devm_kzalloc(&hdev->dev, sizeof(*drv_data), GFP_KERNEL);
+	if (!drv_data)
+		return -ENOMEM;
+
+	ret = hid_parse(hdev);
+	if (ret) {
+		hid_err(hdev, "parse failed\n");
+		return ret;
+	}
+
+	drv_data->device_type = plantronics_device_type(hdev);
+	drv_data->double_key_to = msecs_to_jiffies(PLT_DOUBLE_KEY_TIMEOUT);
+	drv_data->last_key_ts = jiffies - drv_data->double_key_to;
+
+	/* if HZ does not allow ms resolution - disable double key detection */
+	if (drv_data->double_key_to < PLT_DOUBLE_KEY_TIMEOUT)
+		drv_data->double_key_to = 0;
+
+	hid_set_drvdata(hdev, drv_data);
+
+	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT |
+		HID_CONNECT_HIDINPUT_FORCE | HID_CONNECT_HIDDEV_FORCE);
+	if (ret)
+		hid_err(hdev, "hw start failed\n");
+
+	return ret;
+}
+
+static const struct hid_device_id plantronics_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_PLANTRONICS, HID_ANY_ID) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, plantronics_devices);
+
+static const struct hid_usage_id plantronics_usages[] = {
+	{ HID_CP_VOLUMEUP, EV_KEY, HID_ANY_ID },
+	{ HID_CP_VOLUMEDOWN, EV_KEY, HID_ANY_ID },
+	{ HID_TELEPHONY_MUTE, EV_KEY, HID_ANY_ID },
+	{ HID_CONSUMER_MUTE, EV_KEY, HID_ANY_ID },
+	{ PLT2_VOL_UP, EV_KEY, HID_ANY_ID },
+	{ PLT2_VOL_DOWN, EV_KEY, HID_ANY_ID },
+	{ PLT2_MIC_MUTE, EV_KEY, HID_ANY_ID },
+	{ PLT1_VOL_UP, EV_KEY, HID_ANY_ID },
+	{ PLT1_VOL_DOWN, EV_KEY, HID_ANY_ID },
+	{ PLT1_MIC_MUTE, EV_KEY, HID_ANY_ID },
+	{ HID_TERMINATOR, HID_TERMINATOR, HID_TERMINATOR }
+};
+
+static struct hid_driver plantronics_driver = {
+	.name = "plantronics",
+	.id_table = plantronics_devices,
+	.usage_table = plantronics_usages,
+	.input_mapping = plantronics_input_mapping,
+	.event = plantronics_event,
+	.probe = plantronics_probe,
+};
+module_hid_driver(plantronics_driver);
+
+MODULE_AUTHOR("JD Cole <jd.cole@plantronics.com>");
+MODULE_AUTHOR("Terry Junge <terry.junge@plantronics.com>");
+MODULE_DESCRIPTION("Plantronics USB HID Driver");
+MODULE_LICENSE("GPL");