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/reset/reset-eic7700-hsp.c | 113 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 113 insertions(+) create mode 100644 drivers/reset/reset-eic7700-hsp.c (limited to 'drivers/reset/reset-eic7700-hsp.c') diff --git a/drivers/reset/reset-eic7700-hsp.c b/drivers/reset/reset-eic7700-hsp.c new file mode 100644 index 000000000..1575ee4a2 --- /dev/null +++ b/drivers/reset/reset-eic7700-hsp.c @@ -0,0 +1,113 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright 2026, Beijing ESWIN Computing Technology Co., Ltd.. + * All rights reserved. + * + * ESWIN EIC7700 HSP Reset Driver + * + * Authors: Xuyang Dong + */ + +#include +#include +#include +#include +#include + +#include + +/** + * struct eic7700_hsp_reset_data - reset controller information structure + * @rcdev: reset controller entity + * @regmap: regmap handle containing the memory-mapped reset registers + */ +struct eic7700_hsp_reset_data { + struct reset_controller_dev rcdev; + struct regmap *regmap; +}; + +struct eic7700_hsp_reg { + u32 reg; + u32 bit; + bool active_low; +}; + +static inline struct eic7700_hsp_reset_data * +to_eic7700_hsp_reset(struct reset_controller_dev *rcdev) +{ + return container_of(rcdev, struct eic7700_hsp_reset_data, rcdev); +} + +static const struct eic7700_hsp_reg eic7700_hsp_reset[] = { + [EIC7700_HSP_RST_SATA_P0] = {0x340, BIT(0), false}, + [EIC7700_HSP_RST_SATA_PHY] = {0x340, BIT(1), false}, + [EIC7700_HSP_RST_USB0] = {0x800, BIT(24), true}, + [EIC7700_HSP_RST_USB1] = {0x900, BIT(24), true}, + [EIC7700_HSP_RST_USB0_PHY] = {0x800, BIT(25), false}, + [EIC7700_HSP_RST_USB1_PHY] = {0x900, BIT(25), false}, +}; + +static int eic7700_hsp_reset_assert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct eic7700_hsp_reset_data *data = to_eic7700_hsp_reset(rcdev); + + return regmap_assign_bits(data->regmap, eic7700_hsp_reset[id].reg, + eic7700_hsp_reset[id].bit, + !eic7700_hsp_reset[id].active_low); +} + +static int eic7700_hsp_reset_deassert(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct eic7700_hsp_reset_data *data = to_eic7700_hsp_reset(rcdev); + + return regmap_assign_bits(data->regmap, eic7700_hsp_reset[id].reg, + eic7700_hsp_reset[id].bit, + eic7700_hsp_reset[id].active_low); +} + +static const struct reset_control_ops eic7700_hsp_reset_ops = { + .assert = eic7700_hsp_reset_assert, + .deassert = eic7700_hsp_reset_deassert, +}; + +static int eic7700_hsp_reset_probe(struct auxiliary_device *adev, + const struct auxiliary_device_id *id) +{ + struct eic7700_hsp_reset_data *data; + struct device *dev = &adev->dev; + + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->regmap = dev_get_regmap(dev->parent, NULL); + if (!data->regmap) + return dev_err_probe(dev, -ENODEV, "failed to get regmap!\n"); + + data->rcdev.owner = THIS_MODULE; + data->rcdev.ops = &eic7700_hsp_reset_ops; + data->rcdev.of_node = dev->parent->of_node; + data->rcdev.dev = dev; + data->rcdev.nr_resets = ARRAY_SIZE(eic7700_hsp_reset); + + return devm_reset_controller_register(dev, &data->rcdev); +} + +static const struct auxiliary_device_id eic7700_hsp_reset_ids[] = { + { .name = "clk_eic7700_hsp.hsp-reset", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(auxiliary, eic7700_hsp_reset_ids); + +static struct auxiliary_driver eic7700_hsp_reset_driver = { + .probe = eic7700_hsp_reset_probe, + .id_table = eic7700_hsp_reset_ids, +}; + +module_auxiliary_driver(eic7700_hsp_reset_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Xuyang Dong "); +MODULE_DESCRIPTION("ESWIN EIC7700 HSP Reset Controller Driver"); -- cgit v1.3.1