From 93de2a6a4b91b72607136dd656edf03fb399d27f Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Wed, 23 Sep 2026 09:37:21 -0700 Subject: KVM: SEV: Do cache maintenance on the source VM during intra-host migration 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 Signed-off-by: Sean Christopherson Message-ID: <20260923163721.1584779-3-seanjc@google.com> Signed-off-by: Paolo Bonzini --- drivers/hid/hid-speedlink.c | 79 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 79 insertions(+) create mode 100644 drivers/hid/hid-speedlink.c (limited to 'drivers/hid/hid-speedlink.c') diff --git a/drivers/hid/hid-speedlink.c b/drivers/hid/hid-speedlink.c new file mode 100644 index 000000000..22ee078c4 --- /dev/null +++ b/drivers/hid/hid-speedlink.c @@ -0,0 +1,79 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * HID driver for Speedlink Vicious and Divine Cezanne (USB mouse). + * Fixes "jumpy" cursor and removes nonexistent keyboard LEDS from + * the HID descriptor. + * + * Copyright (c) 2011, 2013 Stefan Kriwanek + */ + +/* + */ + +#include +#include +#include + +#include "hid-ids.h" + +static const struct hid_device_id speedlink_devices[] = { + { HID_USB_DEVICE(USB_VENDOR_ID_X_TENSIONS, USB_DEVICE_ID_SPEEDLINK_VAD_CEZANNE)}, + { } +}; + +static int speedlink_input_mapping(struct hid_device *hdev, + struct hid_input *hi, + struct hid_field *field, struct hid_usage *usage, + unsigned long **bit, int *max) +{ + /* + * The Cezanne mouse has a second "keyboard" USB endpoint for it is + * able to map keyboard events to the button presses. + * It sends a standard keyboard report descriptor, though, whose + * LEDs we ignore. + */ + switch (usage->hid & HID_USAGE_PAGE) { + case HID_UP_LED: + return -1; + } + return 0; +} + +static int speedlink_event(struct hid_device *hdev, struct hid_field *field, + struct hid_usage *usage, __s32 value) +{ + /* No other conditions due to usage_table. */ + + /* This fixes the "jumpy" cursor occuring due to invalid events sent + * by the device. Some devices only send them with value==+256, others + * don't. However, catching abs(value)>=256 is restrictive enough not + * to interfere with devices that were bug-free (has been tested). + */ + if (abs(value) >= 256) + return 1; + /* Drop useless distance 0 events (on button clicks etc.) as well */ + if (value == 0) + return 1; + + return 0; +} + +MODULE_DEVICE_TABLE(hid, speedlink_devices); + +static const struct hid_usage_id speedlink_grabbed_usages[] = { + { HID_GD_X, EV_REL, 0 }, + { HID_GD_Y, EV_REL, 1 }, + { HID_ANY_ID - 1, HID_ANY_ID - 1, HID_ANY_ID - 1} +}; + +static struct hid_driver speedlink_driver = { + .name = "speedlink", + .id_table = speedlink_devices, + .usage_table = speedlink_grabbed_usages, + .input_mapping = speedlink_input_mapping, + .event = speedlink_event, +}; +module_hid_driver(speedlink_driver); + +MODULE_DESCRIPTION("HID driver for Speedlink Vicious and Divine Cezanne (USB mouse)"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1