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 --- crypto/sm3.c | 89 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 89 insertions(+) create mode 100644 crypto/sm3.c (limited to 'crypto/sm3.c') diff --git a/crypto/sm3.c b/crypto/sm3.c new file mode 100644 index 000000000..05111a99b --- /dev/null +++ b/crypto/sm3.c @@ -0,0 +1,89 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * SM3 secure hash, as specified by OSCCA GM/T 0004-2012 SM3 and + * described at https://tools.ietf.org/html/draft-shen-sm3-hash-01 + * + * Copyright (C) 2017 ARM Limited or its affiliates. + * Written by Gilad Ben-Yossef + * Copyright (C) 2021 Tianjia Zhang + * Copyright 2026 Google LLC + */ + +#include +#include +#include +#include + +#define SM3_CTX(desc) ((struct sm3_ctx *)shash_desc_ctx(desc)) + +static int crypto_sm3_init(struct shash_desc *desc) +{ + sm3_init(SM3_CTX(desc)); + return 0; +} + +static int crypto_sm3_update(struct shash_desc *desc, + const u8 *data, unsigned int len) +{ + sm3_update(SM3_CTX(desc), data, len); + return 0; +} + +static int crypto_sm3_final(struct shash_desc *desc, u8 *out) +{ + sm3_final(SM3_CTX(desc), out); + return 0; +} + +static int crypto_sm3_digest(struct shash_desc *desc, + const u8 *data, unsigned int len, u8 *out) +{ + sm3(data, len, out); + return 0; +} + +static int crypto_sm3_export_core(struct shash_desc *desc, void *out) +{ + memcpy(out, SM3_CTX(desc), sizeof(struct sm3_ctx)); + return 0; +} + +static int crypto_sm3_import_core(struct shash_desc *desc, const void *in) +{ + memcpy(SM3_CTX(desc), in, sizeof(struct sm3_ctx)); + return 0; +} + +static struct shash_alg sm3_alg = { + .base.cra_name = "sm3", + .base.cra_driver_name = "sm3-lib", + .base.cra_priority = 300, + .base.cra_blocksize = SM3_BLOCK_SIZE, + .base.cra_module = THIS_MODULE, + .digestsize = SM3_DIGEST_SIZE, + .init = crypto_sm3_init, + .update = crypto_sm3_update, + .final = crypto_sm3_final, + .digest = crypto_sm3_digest, + .export_core = crypto_sm3_export_core, + .import_core = crypto_sm3_import_core, + .descsize = sizeof(struct sm3_ctx), +}; + +static int __init crypto_sm3_mod_init(void) +{ + return crypto_register_shash(&sm3_alg); +} +module_init(crypto_sm3_mod_init); + +static void __exit crypto_sm3_mod_exit(void) +{ + crypto_unregister_shash(&sm3_alg); +} +module_exit(crypto_sm3_mod_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Crypto API support for SM3"); + +MODULE_ALIAS_CRYPTO("sm3"); +MODULE_ALIAS_CRYPTO("sm3-lib"); -- cgit v1.3.1