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/md/bcache/debug.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 drivers/md/bcache/debug.h (limited to 'drivers/md/bcache/debug.h') diff --git a/drivers/md/bcache/debug.h b/drivers/md/bcache/debug.h new file mode 100644 index 000000000..fb3d4dff4 --- /dev/null +++ b/drivers/md/bcache/debug.h @@ -0,0 +1,35 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +#ifndef _BCACHE_DEBUG_H +#define _BCACHE_DEBUG_H + +struct bio; +struct cached_dev; +struct cache_set; + +#ifdef CONFIG_BCACHE_DEBUG + +void bch_btree_verify(struct btree *b); +void bch_data_verify(struct cached_dev *dc, struct bio *bio); + +#define expensive_debug_checks(c) ((c)->expensive_debug_checks) +#define key_merging_disabled(c) ((c)->key_merging_disabled) +#define bypass_torture_test(d) ((d)->bypass_torture_test) + +#else /* DEBUG */ + +static inline void bch_btree_verify(struct btree *b) {} +static inline void bch_data_verify(struct cached_dev *dc, struct bio *bio) {} + +#define expensive_debug_checks(c) 0 +#define key_merging_disabled(c) 0 +#define bypass_torture_test(d) 0 + +#endif + +#ifdef CONFIG_DEBUG_FS +void bch_debug_init_cache_set(struct cache_set *c); +#else +static inline void bch_debug_init_cache_set(struct cache_set *c) {} +#endif + +#endif -- cgit v1.3.1