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, 101 insertions, 0 deletions

diff --git a/drivers/hid/hid-rapoo.c b/drivers/hid/hid-rapoo.c
new file mode 100644
index 000000000..5c9c396fa
--- /dev/null
+++ b/drivers/hid/hid-rapoo.c
@@ -0,0 +1,101 @@
+// SPDX-License-Identifier: GPL-2.0
+#include <asm-generic/errno-base.h>
+#include <asm-generic/int-ll64.h>
+#include <linux/bitops.h>
+#include <linux/input.h>
+#include <linux/input-event-codes.h>
+#include <linux/module.h>
+#include <linux/hid.h>
+#include <linux/usb.h>
+
+#include "hid-ids.h"
+
+#define RAPOO_BTN_BACK			0x08
+#define RAPOO_BTN_FORWARD		0x10
+
+static const struct hid_device_id rapoo_devices[] = {
+	{ HID_USB_DEVICE(USB_VENDOR_ID_RAPOO, USB_DEVICE_ID_RAPOO_2_4G_RECEIVER) },
+	{ }
+};
+MODULE_DEVICE_TABLE(hid, rapoo_devices);
+
+static int rapoo_probe(struct hid_device *hdev, const struct hid_device_id *id)
+{
+	int ret;
+	struct input_dev *input;
+
+	ret = hid_parse(hdev);
+	if (ret) {
+		hid_err(hdev, "parse failed\n");
+		return ret;
+	}
+
+	ret = hid_hw_start(hdev, HID_CONNECT_DEFAULT);
+	if (ret) {
+		hid_err(hdev, "start failed\n");
+		return ret;
+	}
+
+	if (hid_is_usb(hdev)) {
+		struct usb_interface *intf = to_usb_interface(hdev->dev.parent);
+
+		if (intf->cur_altsetting->desc.bInterfaceNumber != 1)
+			return 0;
+	}
+
+	input = devm_input_allocate_device(&hdev->dev);
+	if (!input)
+		return -ENOMEM;
+
+	input->name = "Rapoo 2.4G Wireless Mouse";
+	input->phys = "rapoo/input1";
+	input->id.bustype = hdev->bus;
+	input->id.vendor = hdev->vendor;
+	input->id.product = hdev->product;
+	input->id.version = hdev->version;
+
+	__set_bit(EV_KEY, input->evbit);
+	__set_bit(KEY_BACK, input->keybit);
+	__set_bit(KEY_FORWARD, input->keybit);
+
+	ret = input_register_device(input);
+	if (ret)
+		return ret;
+
+	hid_set_drvdata(hdev, input);
+
+	return ret;
+}
+
+static int rapoo_raw_event(struct hid_device *hdev, struct hid_report *report, u8 *data, int size)
+{
+	struct input_dev *input = hid_get_drvdata(hdev);
+
+	if (!input)
+		return 0;
+
+	if (report->id == 1 && size >= 2) {
+		u8 btn = data[1];
+
+		input_report_key(input, KEY_BACK, btn & RAPOO_BTN_BACK);
+		input_report_key(input, KEY_FORWARD, btn & RAPOO_BTN_FORWARD);
+		input_sync(input);
+		return 1;
+	}
+
+	return 0;
+}
+
+static struct hid_driver rapoo_driver = {
+	.name = "hid-rapoo",
+	.id_table = rapoo_devices,
+	.probe = rapoo_probe,
+	.raw_event = rapoo_raw_event,
+};
+
+module_hid_driver(rapoo_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Nguyen Dinh Dang Duong <dangduong31205@gmail.com>");
+MODULE_DESCRIPTION("RAPOO 2.4G Wireless Device Driver");
+