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/crypto/ccp/sp-dev.c | 325 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 325 insertions(+) create mode 100644 drivers/crypto/ccp/sp-dev.c (limited to 'drivers/crypto/ccp/sp-dev.c') diff --git a/drivers/crypto/ccp/sp-dev.c b/drivers/crypto/ccp/sp-dev.c new file mode 100644 index 000000000..f204aa5df --- /dev/null +++ b/drivers/crypto/ccp/sp-dev.c @@ -0,0 +1,325 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * AMD Secure Processor driver + * + * Copyright (C) 2017-2018 Advanced Micro Devices, Inc. + * + * Author: Tom Lendacky + * Author: Gary R Hook + * Author: Brijesh Singh + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include "sev-dev.h" +#include "ccp-dev.h" +#include "sp-dev.h" + +MODULE_AUTHOR("Tom Lendacky "); +MODULE_AUTHOR("Gary R Hook "); +MODULE_LICENSE("GPL"); +MODULE_VERSION("1.1.0"); +MODULE_DESCRIPTION("AMD Secure Processor driver"); + +/* List of SPs, SP count, read-write access lock, and access functions + * + * Lock structure: get sp_unit_lock for reading whenever we need to + * examine the SP list. + */ +static DEFINE_RWLOCK(sp_unit_lock); +static LIST_HEAD(sp_units); + +/* Ever-increasing value to produce unique unit numbers */ +static atomic_t sp_ordinal; + +static void sp_add_device(struct sp_device *sp) +{ + unsigned long flags; + + write_lock_irqsave(&sp_unit_lock, flags); + + list_add_tail(&sp->entry, &sp_units); + + write_unlock_irqrestore(&sp_unit_lock, flags); +} + +static void sp_del_device(struct sp_device *sp) +{ + unsigned long flags; + + write_lock_irqsave(&sp_unit_lock, flags); + + list_del(&sp->entry); + + write_unlock_irqrestore(&sp_unit_lock, flags); +} + +static irqreturn_t sp_irq_handler(int irq, void *data) +{ + struct sp_device *sp = data; + + if (sp->ccp_irq_handler) + sp->ccp_irq_handler(irq, sp->ccp_irq_data); + + if (sp->psp_irq_handler) + sp->psp_irq_handler(irq, sp->psp_irq_data); + + return IRQ_HANDLED; +} + +int sp_request_ccp_irq(struct sp_device *sp, irq_handler_t handler, + const char *name, void *data) +{ + int ret; + + if ((sp->psp_irq == sp->ccp_irq) && sp->dev_vdata->psp_vdata) { + /* Need a common routine to manage all interrupts */ + sp->ccp_irq_data = data; + sp->ccp_irq_handler = handler; + + if (!sp->irq_registered) { + ret = request_irq(sp->ccp_irq, sp_irq_handler, 0, + sp->name, sp); + if (ret) + return ret; + + sp->irq_registered = true; + } + } else { + /* Each sub-device can manage it's own interrupt */ + ret = request_irq(sp->ccp_irq, handler, 0, name, data); + if (ret) + return ret; + } + + return 0; +} + +int sp_request_psp_irq(struct sp_device *sp, irq_handler_t handler, + const char *name, void *data) +{ + int ret; + + if ((sp->psp_irq == sp->ccp_irq) && sp->dev_vdata->ccp_vdata) { + /* Need a common routine to manage all interrupts */ + sp->psp_irq_data = data; + sp->psp_irq_handler = handler; + + if (!sp->irq_registered) { + ret = request_irq(sp->psp_irq, sp_irq_handler, 0, + sp->name, sp); + if (ret) + return ret; + + sp->irq_registered = true; + } + } else { + /* Each sub-device can manage it's own interrupt */ + ret = request_irq(sp->psp_irq, handler, 0, name, data); + if (ret) + return ret; + } + + return 0; +} + +void sp_free_ccp_irq(struct sp_device *sp, void *data) +{ + if ((sp->psp_irq == sp->ccp_irq) && sp->dev_vdata->psp_vdata) { + /* Using common routine to manage all interrupts */ + if (!sp->psp_irq_handler) { + /* Nothing else using it, so free it */ + free_irq(sp->ccp_irq, sp); + + sp->irq_registered = false; + } + + sp->ccp_irq_handler = NULL; + sp->ccp_irq_data = NULL; + } else { + /* Each sub-device can manage it's own interrupt */ + free_irq(sp->ccp_irq, data); + } +} + +void sp_free_psp_irq(struct sp_device *sp, void *data) +{ + if ((sp->psp_irq == sp->ccp_irq) && sp->dev_vdata->ccp_vdata) { + /* Using common routine to manage all interrupts */ + if (!sp->ccp_irq_handler) { + /* Nothing else using it, so free it */ + free_irq(sp->psp_irq, sp); + + sp->irq_registered = false; + } + + sp->psp_irq_handler = NULL; + sp->psp_irq_data = NULL; + } else { + /* Each sub-device can manage it's own interrupt */ + free_irq(sp->psp_irq, data); + } +} + +/** + * sp_alloc_struct - allocate and initialize the sp_device struct + * + * @dev: device struct of the SP + */ +struct sp_device *sp_alloc_struct(struct device *dev) +{ + struct sp_device *sp; + + sp = devm_kzalloc(dev, sizeof(*sp), GFP_KERNEL); + if (!sp) + return NULL; + + sp->dev = dev; + sp->ord = atomic_inc_return(&sp_ordinal); + snprintf(sp->name, SP_MAX_NAME_LEN, "sp-%u", sp->ord); + + return sp; +} + +int sp_init(struct sp_device *sp) +{ + sp_add_device(sp); + + if (sp->dev_vdata->ccp_vdata) + ccp_dev_init(sp); + + if (sp->dev_vdata->psp_vdata) + psp_dev_init(sp); + return 0; +} + +void sp_destroy(struct sp_device *sp) +{ + if (sp->dev_vdata->ccp_vdata) + ccp_dev_destroy(sp); + + if (sp->dev_vdata->psp_vdata) + psp_dev_destroy(sp); + + sp_del_device(sp); +} + +int sp_suspend(struct sp_device *sp) +{ + if (sp->dev_vdata->ccp_vdata) { + ccp_dev_suspend(sp); + } + + return 0; +} + +int sp_resume(struct sp_device *sp) +{ + if (sp->dev_vdata->ccp_vdata) { + ccp_dev_resume(sp); + } + + return 0; +} + +int sp_restore(struct sp_device *sp) +{ + if (sp->psp_data) { + int ret = psp_restore(sp); + + if (ret) + return ret; + } + + return sp_resume(sp); +} + +struct sp_device *sp_get_psp_master_device(void) +{ + struct sp_device *i, *ret = NULL; + unsigned long flags; + + write_lock_irqsave(&sp_unit_lock, flags); + if (list_empty(&sp_units)) + goto unlock; + + list_for_each_entry(i, &sp_units, entry) { + if (i->psp_data && i->get_psp_master_device) { + ret = i->get_psp_master_device(); + break; + } + } + +unlock: + write_unlock_irqrestore(&sp_unit_lock, flags); + return ret; +} + +static int __init sp_mod_init(void) +{ +#ifdef CONFIG_X86 + static bool initialized; + int ret; + + if (initialized) + return 0; + + ret = sp_pci_init(); + if (ret) + return ret; + +#ifdef CONFIG_CRYPTO_DEV_SP_PSP + psp_pci_init(); +#endif + + initialized = true; + + return 0; +#endif + +#ifdef CONFIG_ARM64 + int ret; + + ret = sp_platform_init(); + if (ret) + return ret; + + return 0; +#endif + + return -ENODEV; +} + +#if IS_BUILTIN(CONFIG_KVM_AMD) && IS_ENABLED(CONFIG_KVM_AMD_SEV) +int __init sev_module_init(void) +{ + return sp_mod_init(); +} +#endif + +static void __exit sp_mod_exit(void) +{ +#ifdef CONFIG_X86 + +#ifdef CONFIG_CRYPTO_DEV_SP_PSP + psp_pci_exit(); +#endif + + sp_pci_exit(); +#endif + +#ifdef CONFIG_ARM64 + sp_platform_exit(); +#endif +} + +module_init(sp_mod_init); +module_exit(sp_mod_exit); -- cgit v1.3.1