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-emsff.c | 115 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 115 insertions(+) create mode 100644 drivers/hid/hid-emsff.c (limited to 'drivers/hid/hid-emsff.c') diff --git a/drivers/hid/hid-emsff.c b/drivers/hid/hid-emsff.c new file mode 100644 index 000000000..d8e559e05 --- /dev/null +++ b/drivers/hid/hid-emsff.c @@ -0,0 +1,115 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Force feedback support for EMS Trio Linker Plus II + * + * Copyright (c) 2010 Ignaz Forster + */ + +/* + */ + + +#include +#include +#include + +#include "hid-ids.h" + +struct emsff_device { + struct hid_report *report; +}; + +static int emsff_play(struct input_dev *dev, void *data, + struct ff_effect *effect) +{ + struct hid_device *hid = input_get_drvdata(dev); + struct emsff_device *emsff = data; + int weak, strong; + + weak = effect->u.rumble.weak_magnitude; + strong = effect->u.rumble.strong_magnitude; + + dbg_hid("called with 0x%04x 0x%04x\n", strong, weak); + + weak = weak * 0xff / 0xffff; + strong = strong * 0xff / 0xffff; + + emsff->report->field[0]->value[1] = weak; + emsff->report->field[0]->value[2] = strong; + + dbg_hid("running with 0x%02x 0x%02x\n", strong, weak); + hid_hw_request(hid, emsff->report, HID_REQ_SET_REPORT); + + return 0; +} + +static int ems_input_configured(struct hid_device *hid, struct hid_input *hidinput) +{ + struct emsff_device *emsff; + struct hid_report *report; + struct list_head *report_list = + &hid->report_enum[HID_OUTPUT_REPORT].report_list; + struct input_dev *dev = hidinput->input; + int error; + + if (!list_is_first(&hidinput->list, &hid->inputs)) + return 0; + + report = list_first_entry_or_null(report_list, struct hid_report, list); + if (!report) { + hid_err(hid, "no output reports found\n"); + return -ENODEV; + } + if (report->maxfield < 1) { + hid_err(hid, "no fields in the report\n"); + return -ENODEV; + } + + if (report->field[0]->report_count < 7) { + hid_err(hid, "not enough values in the field\n"); + return -ENODEV; + } + + emsff = kzalloc_obj(struct emsff_device); + if (!emsff) + return -ENOMEM; + + emsff->report = report; + set_bit(FF_RUMBLE, dev->ffbit); + + error = input_ff_create_memless(dev, emsff, emsff_play); + if (error) { + kfree(emsff); + return error; + } + + emsff->report->field[0]->value[0] = 0x01; + emsff->report->field[0]->value[1] = 0x00; + emsff->report->field[0]->value[2] = 0x00; + emsff->report->field[0]->value[3] = 0x00; + emsff->report->field[0]->value[4] = 0x00; + emsff->report->field[0]->value[5] = 0x00; + emsff->report->field[0]->value[6] = 0x00; + hid_hw_request(hid, emsff->report, HID_REQ_SET_REPORT); + + hid_info(hid, "force feedback for EMS based devices by Ignaz Forster \n"); + + return 0; +} + +static const struct hid_device_id ems_devices[] = { + { HID_USB_DEVICE(USB_VENDOR_ID_EMS, USB_DEVICE_ID_EMS_TRIO_LINKER_PLUS_II) }, + { } +}; +MODULE_DEVICE_TABLE(hid, ems_devices); + +static struct hid_driver ems_driver = { + .name = "hkems", + .id_table = ems_devices, + .input_configured = ems_input_configured, +}; +module_hid_driver(ems_driver); + +MODULE_DESCRIPTION("Force feedback support for EMS Trio Linker Plus II"); +MODULE_LICENSE("GPL"); + -- cgit v1.3.1