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-generic.c | 98 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 98 insertions(+) create mode 100644 drivers/hid/hid-generic.c (limited to 'drivers/hid/hid-generic.c') diff --git a/drivers/hid/hid-generic.c b/drivers/hid/hid-generic.c new file mode 100644 index 000000000..c2de91674 --- /dev/null +++ b/drivers/hid/hid-generic.c @@ -0,0 +1,98 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * HID support for Linux + * + * Copyright (c) 1999 Andreas Gal + * Copyright (c) 2000-2005 Vojtech Pavlik + * Copyright (c) 2005 Michael Haboustak for Concept2, Inc + * Copyright (c) 2007-2008 Oliver Neukum + * Copyright (c) 2006-2012 Jiri Kosina + * Copyright (c) 2012 Henrik Rydberg + */ + +/* + */ + +#include +#include +#include +#include +#include + +#include + +static struct hid_driver hid_generic; + +static int __check_hid_generic(struct device_driver *drv, void *data) +{ + struct hid_driver *hdrv = to_hid_driver(drv); + struct hid_device *hdev = data; + + if (hdrv == &hid_generic) + return 0; + + return hid_match_device(hdev, hdrv) != NULL; +} + +static bool hid_generic_match(struct hid_device *hdev, + bool ignore_special_driver) +{ + if (ignore_special_driver) + return true; + + if (hdev->quirks & HID_QUIRK_IGNORE_SPECIAL_DRIVER) + return true; + + if (hdev->quirks & HID_QUIRK_HAVE_SPECIAL_DRIVER) + return false; + + /* + * If any other driver wants the device, leave the device to this other + * driver. + */ + if (bus_for_each_drv(&hid_bus_type, NULL, hdev, __check_hid_generic)) + return false; + + return true; +} + +static int hid_generic_probe(struct hid_device *hdev, + const struct hid_device_id *id) +{ + int ret; + + hdev->quirks |= HID_QUIRK_INPUT_PER_APP; + + ret = hid_parse(hdev); + if (ret) + return ret; + + return hid_hw_start(hdev, HID_CONNECT_DEFAULT); +} + +static int hid_generic_reset_resume(struct hid_device *hdev) +{ + if (hdev->claimed & HID_CLAIMED_INPUT) + hidinput_reset_resume(hdev); + + return 0; +} + +static const struct hid_device_id hid_table[] = { + { HID_DEVICE(HID_BUS_ANY, HID_GROUP_ANY, HID_ANY_ID, HID_ANY_ID) }, + { } +}; +MODULE_DEVICE_TABLE(hid, hid_table); + +static struct hid_driver hid_generic = { + .name = "hid-generic", + .id_table = hid_table, + .match = hid_generic_match, + .probe = hid_generic_probe, + .reset_resume = hid_generic_reset_resume, +}; +module_hid_driver(hid_generic); + +MODULE_AUTHOR("Henrik Rydberg"); +MODULE_DESCRIPTION("HID generic driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1