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/mfd/rohm-pwrbutton.c | 112 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 112 insertions(+) create mode 100644 drivers/mfd/rohm-pwrbutton.c (limited to 'drivers/mfd/rohm-pwrbutton.c') diff --git a/drivers/mfd/rohm-pwrbutton.c b/drivers/mfd/rohm-pwrbutton.c new file mode 100644 index 000000000..96a6d1f01 --- /dev/null +++ b/drivers/mfd/rohm-pwrbutton.c @@ -0,0 +1,112 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Shared helper for ROHM PMIC power button registration + * + * Copyright 2018, 2019 ROHM Semiconductors + * Copyright 2026 Google LLC + */ + +#include +#include +#include +#include +#include +#include +#include + +#include "rohm-pwrbutton.h" + +#define GPIO_KEYS 0 /* Node corresponding to gpio-keys device itself */ +#define PWRON_KEY 1 /* Node describing power button in gpio-keys */ + +static int rohm_pwrbutton_register_swnodes(const struct software_node *nodes) +{ + const struct software_node * const node_group[] = { + &nodes[GPIO_KEYS], &nodes[PWRON_KEY], NULL + }; + + return software_node_register_node_group(node_group); +} + +static void rohm_pwrbutton_unregister_swnodes(void *data) +{ + const struct software_node *nodes = data; + const struct software_node * const node_group[] = { + &nodes[GPIO_KEYS], &nodes[PWRON_KEY], NULL + }; + + software_node_unregister_node_group(node_group); +} + +int rohm_register_pwrbutton(struct device *dev, int irq, const char *name, + bool wakeup, struct irq_domain *irq_domain) +{ + const struct resource res[] = { + DEFINE_RES_IRQ_NAMED(irq, name), + }; + struct mfd_cell gpio_keys_cell = { + .name = "gpio-keys", + .resources = res, + .num_resources = ARRAY_SIZE(res), + }; + struct property_entry *parent_props; + struct property_entry *child_props; + struct software_node *nodes; + int n_props; + int ret; + + if (irq <= 0) + return -EINVAL; + + nodes = devm_kcalloc(dev, 2, sizeof(*nodes), GFP_KERNEL); + if (!nodes) + return -ENOMEM; + + nodes[GPIO_KEYS].name = devm_kasprintf(dev, GFP_KERNEL, "%s-power-key", dev_name(dev)); + if (!nodes[GPIO_KEYS].name) + return -ENOMEM; + + parent_props = devm_kcalloc(dev, 2, sizeof(*parent_props), GFP_KERNEL); + if (!parent_props) + return -ENOMEM; + + parent_props[0] = PROPERTY_ENTRY_STRING("label", name); + nodes[GPIO_KEYS].properties = parent_props; + + n_props = 2; /* linux,code and terminator */ + if (wakeup) + n_props++; + + child_props = devm_kcalloc(dev, n_props, sizeof(*child_props), GFP_KERNEL); + if (!child_props) + return -ENOMEM; + + child_props[0] = PROPERTY_ENTRY_U32("linux,code", KEY_POWER); + if (wakeup) + child_props[1] = PROPERTY_ENTRY_BOOL("wakeup-source"); + + nodes[PWRON_KEY].parent = &nodes[GPIO_KEYS]; + nodes[PWRON_KEY].properties = child_props; + + ret = rohm_pwrbutton_register_swnodes(nodes); + if (ret) + return ret; + + ret = devm_add_action_or_reset(dev, rohm_pwrbutton_unregister_swnodes, nodes); + if (ret) + return ret; + + gpio_keys_cell.swnode = &nodes[GPIO_KEYS]; + + ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_AUTO, &gpio_keys_cell, 1, + NULL, 0, irq_domain); + if (ret) + return dev_err_probe(dev, ret, "Failed to register power-button"); + + return 0; +} +EXPORT_SYMBOL_GPL(rohm_register_pwrbutton); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Dmitry Torokhov "); +MODULE_DESCRIPTION("Shared helper for ROHM PMIC power button registration"); -- cgit v1.3.1