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/features.h | 113 +++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 113 insertions(+) create mode 100644 drivers/md/bcache/features.h (limited to 'drivers/md/bcache/features.h') diff --git a/drivers/md/bcache/features.h b/drivers/md/bcache/features.h new file mode 100644 index 000000000..09161b89c --- /dev/null +++ b/drivers/md/bcache/features.h @@ -0,0 +1,113 @@ +/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */ +#ifndef _BCACHE_FEATURES_H +#define _BCACHE_FEATURES_H + +#include +#include + +#include "bcache_ondisk.h" + +#define BCH_FEATURE_COMPAT 0 +#define BCH_FEATURE_RO_COMPAT 1 +#define BCH_FEATURE_INCOMPAT 2 +#define BCH_FEATURE_TYPE_MASK 0x03 + +/* Feature set definition */ +/* Incompat feature set */ +/* 32bit bucket size, obsoleted */ +#define BCH_FEATURE_INCOMPAT_OBSO_LARGE_BUCKET 0x0001 +/* real bucket size is (1 << bucket_size) */ +#define BCH_FEATURE_INCOMPAT_LOG_LARGE_BUCKET_SIZE 0x0002 + +#define BCH_FEATURE_COMPAT_SUPP 0 +#define BCH_FEATURE_RO_COMPAT_SUPP 0 +#define BCH_FEATURE_INCOMPAT_SUPP (BCH_FEATURE_INCOMPAT_OBSO_LARGE_BUCKET| \ + BCH_FEATURE_INCOMPAT_LOG_LARGE_BUCKET_SIZE) + +#define BCH_HAS_COMPAT_FEATURE(sb, mask) \ + ((sb)->feature_compat & (mask)) +#define BCH_HAS_RO_COMPAT_FEATURE(sb, mask) \ + ((sb)->feature_ro_compat & (mask)) +#define BCH_HAS_INCOMPAT_FEATURE(sb, mask) \ + ((sb)->feature_incompat & (mask)) + +#define BCH_FEATURE_COMPAT_FUNCS(name, flagname) \ +static inline int bch_has_feature_##name(struct cache_sb *sb) \ +{ \ + if (sb->version < BCACHE_SB_VERSION_CDEV_WITH_FEATURES) \ + return 0; \ + return (((sb)->feature_compat & \ + BCH##_FEATURE_COMPAT_##flagname) != 0); \ +} \ +static inline void bch_set_feature_##name(struct cache_sb *sb) \ +{ \ + (sb)->feature_compat |= \ + BCH##_FEATURE_COMPAT_##flagname; \ +} \ +static inline void bch_clear_feature_##name(struct cache_sb *sb) \ +{ \ + (sb)->feature_compat &= \ + ~BCH##_FEATURE_COMPAT_##flagname; \ +} + +#define BCH_FEATURE_RO_COMPAT_FUNCS(name, flagname) \ +static inline int bch_has_feature_##name(struct cache_sb *sb) \ +{ \ + if (sb->version < BCACHE_SB_VERSION_CDEV_WITH_FEATURES) \ + return 0; \ + return (((sb)->feature_ro_compat & \ + BCH##_FEATURE_RO_COMPAT_##flagname) != 0); \ +} \ +static inline void bch_set_feature_##name(struct cache_sb *sb) \ +{ \ + (sb)->feature_ro_compat |= \ + BCH##_FEATURE_RO_COMPAT_##flagname; \ +} \ +static inline void bch_clear_feature_##name(struct cache_sb *sb) \ +{ \ + (sb)->feature_ro_compat &= \ + ~BCH##_FEATURE_RO_COMPAT_##flagname; \ +} + +#define BCH_FEATURE_INCOMPAT_FUNCS(name, flagname) \ +static inline int bch_has_feature_##name(struct cache_sb *sb) \ +{ \ + if (sb->version < BCACHE_SB_VERSION_CDEV_WITH_FEATURES) \ + return 0; \ + return (((sb)->feature_incompat & \ + BCH##_FEATURE_INCOMPAT_##flagname) != 0); \ +} \ +static inline void bch_set_feature_##name(struct cache_sb *sb) \ +{ \ + (sb)->feature_incompat |= \ + BCH##_FEATURE_INCOMPAT_##flagname; \ +} \ +static inline void bch_clear_feature_##name(struct cache_sb *sb) \ +{ \ + (sb)->feature_incompat &= \ + ~BCH##_FEATURE_INCOMPAT_##flagname; \ +} + +BCH_FEATURE_INCOMPAT_FUNCS(obso_large_bucket, OBSO_LARGE_BUCKET); +BCH_FEATURE_INCOMPAT_FUNCS(large_bucket, LOG_LARGE_BUCKET_SIZE); + +static inline bool bch_has_unknown_compat_features(struct cache_sb *sb) +{ + return ((sb->feature_compat & ~BCH_FEATURE_COMPAT_SUPP) != 0); +} + +static inline bool bch_has_unknown_ro_compat_features(struct cache_sb *sb) +{ + return ((sb->feature_ro_compat & ~BCH_FEATURE_RO_COMPAT_SUPP) != 0); +} + +static inline bool bch_has_unknown_incompat_features(struct cache_sb *sb) +{ + return ((sb->feature_incompat & ~BCH_FEATURE_INCOMPAT_SUPP) != 0); +} + +int bch_print_cache_set_feature_compat(struct cache_set *c, char *buf, int size); +int bch_print_cache_set_feature_ro_compat(struct cache_set *c, char *buf, int size); +int bch_print_cache_set_feature_incompat(struct cache_set *c, char *buf, int size); + +#endif -- cgit v1.3.1