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/firmware/dmi-id.c | 265 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 265 insertions(+) create mode 100644 drivers/firmware/dmi-id.c (limited to 'drivers/firmware/dmi-id.c') diff --git a/drivers/firmware/dmi-id.c b/drivers/firmware/dmi-id.c new file mode 100644 index 000000000..477a37e2e --- /dev/null +++ b/drivers/firmware/dmi-id.c @@ -0,0 +1,265 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Export SMBIOS/DMI info via sysfs to userspace + * + * Copyright 2007, Lennart Poettering + */ + +#include +#include +#include +#include +#include +#include + +struct dmi_device_attribute{ + struct device_attribute dev_attr; + int field; +}; +#define to_dmi_dev_attr(_dev_attr) \ + container_of(_dev_attr, struct dmi_device_attribute, dev_attr) + +static ssize_t sys_dmi_field_show(struct device *dev, + struct device_attribute *attr, + char *page) +{ + int field = to_dmi_dev_attr(attr)->field; + ssize_t len; + len = scnprintf(page, PAGE_SIZE, "%s\n", dmi_get_system_info(field)); + page[len-1] = '\n'; + return len; +} + +#define DMI_ATTR(_name, _mode, _show, _field) \ + { .dev_attr = __ATTR(_name, _mode, _show, NULL), \ + .field = _field } + +#define DEFINE_DMI_ATTR_WITH_SHOW(_name, _mode, _field) \ +static struct dmi_device_attribute sys_dmi_##_name##_attr = \ + DMI_ATTR(_name, _mode, sys_dmi_field_show, _field); + +DEFINE_DMI_ATTR_WITH_SHOW(bios_vendor, 0444, DMI_BIOS_VENDOR); +DEFINE_DMI_ATTR_WITH_SHOW(bios_version, 0444, DMI_BIOS_VERSION); +DEFINE_DMI_ATTR_WITH_SHOW(bios_date, 0444, DMI_BIOS_DATE); +DEFINE_DMI_ATTR_WITH_SHOW(sys_vendor, 0444, DMI_SYS_VENDOR); +DEFINE_DMI_ATTR_WITH_SHOW(bios_release, 0444, DMI_BIOS_RELEASE); +DEFINE_DMI_ATTR_WITH_SHOW(ec_firmware_release, 0444, DMI_EC_FIRMWARE_RELEASE); +DEFINE_DMI_ATTR_WITH_SHOW(product_name, 0444, DMI_PRODUCT_NAME); +DEFINE_DMI_ATTR_WITH_SHOW(product_version, 0444, DMI_PRODUCT_VERSION); +DEFINE_DMI_ATTR_WITH_SHOW(product_serial, 0400, DMI_PRODUCT_SERIAL); +DEFINE_DMI_ATTR_WITH_SHOW(product_uuid, 0400, DMI_PRODUCT_UUID); +DEFINE_DMI_ATTR_WITH_SHOW(product_sku, 0444, DMI_PRODUCT_SKU); +DEFINE_DMI_ATTR_WITH_SHOW(product_family, 0444, DMI_PRODUCT_FAMILY); +DEFINE_DMI_ATTR_WITH_SHOW(board_vendor, 0444, DMI_BOARD_VENDOR); +DEFINE_DMI_ATTR_WITH_SHOW(board_name, 0444, DMI_BOARD_NAME); +DEFINE_DMI_ATTR_WITH_SHOW(board_version, 0444, DMI_BOARD_VERSION); +DEFINE_DMI_ATTR_WITH_SHOW(board_serial, 0400, DMI_BOARD_SERIAL); +DEFINE_DMI_ATTR_WITH_SHOW(board_asset_tag, 0444, DMI_BOARD_ASSET_TAG); +DEFINE_DMI_ATTR_WITH_SHOW(chassis_vendor, 0444, DMI_CHASSIS_VENDOR); +DEFINE_DMI_ATTR_WITH_SHOW(chassis_type, 0444, DMI_CHASSIS_TYPE); +DEFINE_DMI_ATTR_WITH_SHOW(chassis_version, 0444, DMI_CHASSIS_VERSION); +DEFINE_DMI_ATTR_WITH_SHOW(chassis_serial, 0400, DMI_CHASSIS_SERIAL); +DEFINE_DMI_ATTR_WITH_SHOW(chassis_asset_tag, 0444, DMI_CHASSIS_ASSET_TAG); + +static void ascii_filter(char *d, const char *s) +{ + /* Filter out characters we don't want to see in the modalias string */ + for (; *s; s++) + if (*s > ' ' && *s < 127 && *s != ':') + *(d++) = *s; + + *d = 0; +} + +static ssize_t get_modalias(char *buffer, size_t buffer_size) +{ + /* + * Note new fields need to be added at the end to keep compatibility + * with udev's hwdb which does matches on "`cat dmi/id/modalias`*". + */ + static const struct mafield { + const char *prefix; + int field; + } fields[] = { + { "bvn", DMI_BIOS_VENDOR }, + { "bvr", DMI_BIOS_VERSION }, + { "bd", DMI_BIOS_DATE }, + { "br", DMI_BIOS_RELEASE }, + { "efr", DMI_EC_FIRMWARE_RELEASE }, + { "svn", DMI_SYS_VENDOR }, + { "pn", DMI_PRODUCT_NAME }, + { "pvr", DMI_PRODUCT_VERSION }, + { "rvn", DMI_BOARD_VENDOR }, + { "rn", DMI_BOARD_NAME }, + { "rvr", DMI_BOARD_VERSION }, + { "cvn", DMI_CHASSIS_VENDOR }, + { "ct", DMI_CHASSIS_TYPE }, + { "cvr", DMI_CHASSIS_VERSION }, + { "sku", DMI_PRODUCT_SKU }, + { "pfa", DMI_PRODUCT_FAMILY }, + { NULL, DMI_NONE } + }; + + ssize_t l, left; + char *p; + const struct mafield *f; + + strcpy(buffer, "dmi"); + p = buffer + 3; left = buffer_size - 4; + + for (f = fields; f->prefix && left > 0; f++) { + const char *c; + char *t; + + c = dmi_get_system_info(f->field); + if (!c) + continue; + + t = kmalloc(strlen(c) + 1, GFP_KERNEL); + if (!t) + break; + ascii_filter(t, c); + l = scnprintf(p, left, ":%s%s", f->prefix, t); + kfree(t); + + p += l; + left -= l; + } + + p[0] = ':'; + p[1] = 0; + + return p - buffer + 1; +} + +static ssize_t sys_dmi_modalias_show(struct device *dev, + struct device_attribute *attr, char *page) +{ + ssize_t r; + r = get_modalias(page, PAGE_SIZE-1); + page[r] = '\n'; + page[r+1] = 0; + return r+1; +} + +static struct device_attribute sys_dmi_modalias_attr = + __ATTR(modalias, 0444, sys_dmi_modalias_show, NULL); + +static struct attribute *sys_dmi_attributes[DMI_STRING_MAX+2]; + +static struct attribute_group sys_dmi_attribute_group = { + .attrs = sys_dmi_attributes, +}; + +static const struct attribute_group* sys_dmi_attribute_groups[] = { + &sys_dmi_attribute_group, + NULL +}; + +static int dmi_dev_uevent(const struct device *dev, struct kobj_uevent_env *env) +{ + ssize_t len; + + if (add_uevent_var(env, "MODALIAS=")) + return -ENOMEM; + len = get_modalias(&env->buf[env->buflen - 1], + sizeof(env->buf) - env->buflen); + if (len >= (sizeof(env->buf) - env->buflen)) + return -ENOMEM; + env->buflen += len; + return 0; +} + +static void dmi_dev_release(struct device *dev) +{ + kfree(dev); +} + +static struct class dmi_class = { + .name = "dmi", + .dev_release = dmi_dev_release, + .dev_uevent = dmi_dev_uevent, +}; + +static struct device *dmi_dev; + +/* Initialization */ + +#define ADD_DMI_ATTR(_name, _field) \ + if (dmi_get_system_info(_field)) \ + sys_dmi_attributes[i++] = &sys_dmi_##_name##_attr.dev_attr.attr; + +/* In a separate function to keep gcc 3.2 happy - do NOT merge this in + dmi_id_init! */ +static void __init dmi_id_init_attr_table(void) +{ + int i; + + /* Not necessarily all DMI fields are available on all + * systems, hence let's built an attribute table of just + * what's available */ + i = 0; + ADD_DMI_ATTR(bios_vendor, DMI_BIOS_VENDOR); + ADD_DMI_ATTR(bios_version, DMI_BIOS_VERSION); + ADD_DMI_ATTR(bios_date, DMI_BIOS_DATE); + ADD_DMI_ATTR(bios_release, DMI_BIOS_RELEASE); + ADD_DMI_ATTR(ec_firmware_release, DMI_EC_FIRMWARE_RELEASE); + ADD_DMI_ATTR(sys_vendor, DMI_SYS_VENDOR); + ADD_DMI_ATTR(product_name, DMI_PRODUCT_NAME); + ADD_DMI_ATTR(product_version, DMI_PRODUCT_VERSION); + ADD_DMI_ATTR(product_serial, DMI_PRODUCT_SERIAL); + ADD_DMI_ATTR(product_uuid, DMI_PRODUCT_UUID); + ADD_DMI_ATTR(product_family, DMI_PRODUCT_FAMILY); + ADD_DMI_ATTR(product_sku, DMI_PRODUCT_SKU); + ADD_DMI_ATTR(board_vendor, DMI_BOARD_VENDOR); + ADD_DMI_ATTR(board_name, DMI_BOARD_NAME); + ADD_DMI_ATTR(board_version, DMI_BOARD_VERSION); + ADD_DMI_ATTR(board_serial, DMI_BOARD_SERIAL); + ADD_DMI_ATTR(board_asset_tag, DMI_BOARD_ASSET_TAG); + ADD_DMI_ATTR(chassis_vendor, DMI_CHASSIS_VENDOR); + ADD_DMI_ATTR(chassis_type, DMI_CHASSIS_TYPE); + ADD_DMI_ATTR(chassis_version, DMI_CHASSIS_VERSION); + ADD_DMI_ATTR(chassis_serial, DMI_CHASSIS_SERIAL); + ADD_DMI_ATTR(chassis_asset_tag, DMI_CHASSIS_ASSET_TAG); + sys_dmi_attributes[i++] = &sys_dmi_modalias_attr.attr; +} + +static int __init dmi_id_init(void) +{ + int ret; + + if (!dmi_available) + return -ENODEV; + + dmi_id_init_attr_table(); + + ret = class_register(&dmi_class); + if (ret) + return ret; + + dmi_dev = kzalloc_obj(*dmi_dev); + if (!dmi_dev) { + ret = -ENOMEM; + goto fail_class_unregister; + } + + dmi_dev->class = &dmi_class; + dev_set_name(dmi_dev, "id"); + dmi_dev->groups = sys_dmi_attribute_groups; + + ret = device_register(dmi_dev); + if (ret) + goto fail_put_dmi_dev; + + return 0; + +fail_put_dmi_dev: + put_device(dmi_dev); + +fail_class_unregister: + class_unregister(&dmi_class); + + return ret; +} + +arch_initcall(dmi_id_init); -- cgit v1.3.1