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/input/misc/gpio-beeper.c | 114 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 114 insertions(+) create mode 100644 drivers/input/misc/gpio-beeper.c (limited to 'drivers/input/misc/gpio-beeper.c') diff --git a/drivers/input/misc/gpio-beeper.c b/drivers/input/misc/gpio-beeper.c new file mode 100644 index 000000000..3d65cb4f4 --- /dev/null +++ b/drivers/input/misc/gpio-beeper.c @@ -0,0 +1,114 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Generic GPIO beeper driver + * + * Copyright (C) 2013-2014 Alexander Shiyan + */ + +#include +#include +#include +#include +#include +#include + +#define BEEPER_MODNAME "gpio-beeper" + +struct gpio_beeper { + struct work_struct work; + struct gpio_desc *desc; + bool beeping; +}; + +static void gpio_beeper_toggle(struct gpio_beeper *beep, bool on) +{ + gpiod_set_value_cansleep(beep->desc, on); +} + +static void gpio_beeper_work(struct work_struct *work) +{ + struct gpio_beeper *beep = container_of(work, struct gpio_beeper, work); + + gpio_beeper_toggle(beep, beep->beeping); +} + +static int gpio_beeper_event(struct input_dev *dev, unsigned int type, + unsigned int code, int value) +{ + struct gpio_beeper *beep = input_get_drvdata(dev); + + if (type != EV_SND || code != SND_BELL) + return -ENOTSUPP; + + if (value < 0) + return -EINVAL; + + beep->beeping = value; + /* Schedule work to actually turn the beeper on or off */ + schedule_work(&beep->work); + + return 0; +} + +static void gpio_beeper_close(struct input_dev *input) +{ + struct gpio_beeper *beep = input_get_drvdata(input); + + cancel_work_sync(&beep->work); + gpio_beeper_toggle(beep, false); +} + +static int gpio_beeper_probe(struct platform_device *pdev) +{ + struct gpio_beeper *beep; + struct input_dev *input; + + beep = devm_kzalloc(&pdev->dev, sizeof(*beep), GFP_KERNEL); + if (!beep) + return -ENOMEM; + + beep->desc = devm_gpiod_get(&pdev->dev, NULL, GPIOD_OUT_LOW); + if (IS_ERR(beep->desc)) + return PTR_ERR(beep->desc); + + input = devm_input_allocate_device(&pdev->dev); + if (!input) + return -ENOMEM; + + INIT_WORK(&beep->work, gpio_beeper_work); + + input->name = pdev->name; + input->id.bustype = BUS_HOST; + input->id.vendor = 0x0001; + input->id.product = 0x0001; + input->id.version = 0x0100; + input->close = gpio_beeper_close; + input->event = gpio_beeper_event; + + input_set_capability(input, EV_SND, SND_BELL); + + input_set_drvdata(input, beep); + + return input_register_device(input); +} + +#ifdef CONFIG_OF +static const struct of_device_id gpio_beeper_of_match[] = { + { .compatible = "gpio-beeper", }, + { } +}; +MODULE_DEVICE_TABLE(of, gpio_beeper_of_match); +#endif + +static struct platform_driver gpio_beeper_platform_driver = { + .driver = { + .name = BEEPER_MODNAME, + .of_match_table = of_match_ptr(gpio_beeper_of_match), + }, + .probe = gpio_beeper_probe, +}; +module_platform_driver(gpio_beeper_platform_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Alexander Shiyan "); +MODULE_DESCRIPTION("Generic GPIO beeper driver"); -- cgit v1.3.1