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/nvmem/internals.h | 65 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 65 insertions(+) create mode 100644 drivers/nvmem/internals.h (limited to 'drivers/nvmem/internals.h') diff --git a/drivers/nvmem/internals.h b/drivers/nvmem/internals.h new file mode 100644 index 000000000..4e610deea --- /dev/null +++ b/drivers/nvmem/internals.h @@ -0,0 +1,65 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef _LINUX_NVMEM_INTERNALS_H +#define _LINUX_NVMEM_INTERNALS_H + +#include +#include +#include + +/* Hold pointers to callbacks owned by the nvmem provider module. */ +struct nvmem_operations { + nvmem_reg_read_t reg_read; + nvmem_reg_write_t reg_write; +}; + +struct nvmem_device { + struct module *owner; + struct device dev; + int stride; + int word_size; + int id; + struct kref refcnt; + size_t size; + bool read_only; + bool root_only; + int flags; + enum nvmem_type type; + struct bin_attribute eeprom; + struct device *base_dev; + struct list_head cells; + void (*fixup_dt_cell_info)(struct nvmem_device *nvmem, + struct nvmem_cell_info *cell); + const struct nvmem_keepout *keepout; + unsigned int nkeepout; + struct gpio_desc *wp_gpio; + struct nvmem_layout *layout; + struct nvmem_operations *ops; + void *priv; + bool sysfs_cells_populated; +}; + +int nvmem_add_cells_from_dt(struct nvmem_device *nvmem, struct device_node *np); + +#if IS_ENABLED(CONFIG_OF) +int nvmem_layout_bus_register(void); +void nvmem_layout_bus_unregister(void); +int nvmem_populate_layout(struct nvmem_device *nvmem); +void nvmem_destroy_layout(struct nvmem_device *nvmem); +#else /* CONFIG_OF */ +static inline int nvmem_layout_bus_register(void) +{ + return 0; +} + +static inline void nvmem_layout_bus_unregister(void) {} + +static inline int nvmem_populate_layout(struct nvmem_device *nvmem) +{ + return 0; +} + +static inline void nvmem_destroy_layout(struct nvmem_device *nvmem) { } +#endif /* CONFIG_OF */ + +#endif /* ifndef _LINUX_NVMEM_INTERNALS_H */ -- cgit v1.3.1