KVM: SEV: Do cache maintenance on the source VM during intra-host migrationgrafted

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 <fane@google.com>
Signed-off-by: Sean Christopherson <seanjc@google.com>
Message-ID: <20260923163721.1584779-3-seanjc@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 165 insertions, 0 deletions

diff --git a/include/trace/misc/fs.h b/include/trace/misc/fs.h
new file mode 100644
index 000000000..7ead1c61f
--- /dev/null
+++ b/include/trace/misc/fs.h
@@ -0,0 +1,165 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Display helpers for generic filesystem items
+ *
+ * Author: Chuck Lever <chuck.lever@oracle.com>
+ *
+ * Copyright (c) 2020, Oracle and/or its affiliates.
+ */
+
+#include <linux/fs.h>
+
+#define show_fs_dirent_type(x) \
+	__print_symbolic(x, \
+		{ DT_UNKNOWN,		"UNKNOWN" }, \
+		{ DT_FIFO,		"FIFO" }, \
+		{ DT_CHR,		"CHR" }, \
+		{ DT_DIR,		"DIR" }, \
+		{ DT_BLK,		"BLK" }, \
+		{ DT_REG,		"REG" }, \
+		{ DT_LNK,		"LNK" }, \
+		{ DT_SOCK,		"SOCK" }, \
+		{ DT_WHT,		"WHT" })
+
+#define show_fs_fcntl_open_flags(x) \
+	__print_flags(x, "|", \
+		{ O_WRONLY,		"O_WRONLY" }, \
+		{ O_RDWR,		"O_RDWR" }, \
+		{ O_CREAT,		"O_CREAT" }, \
+		{ O_EXCL,		"O_EXCL" }, \
+		{ O_NOCTTY,		"O_NOCTTY" }, \
+		{ O_TRUNC,		"O_TRUNC" }, \
+		{ O_APPEND,		"O_APPEND" }, \
+		{ O_NONBLOCK,		"O_NONBLOCK" }, \
+		{ O_DSYNC,		"O_DSYNC" }, \
+		{ O_DIRECT,		"O_DIRECT" }, \
+		{ O_LARGEFILE,		"O_LARGEFILE" }, \
+		{ O_DIRECTORY,		"O_DIRECTORY" }, \
+		{ O_NOFOLLOW,		"O_NOFOLLOW" }, \
+		{ O_NOATIME,		"O_NOATIME" }, \
+		{ O_CLOEXEC,		"O_CLOEXEC" })
+
+#define __fmode_flag(x)	{ (__force unsigned long)FMODE_##x, #x }
+#define show_fs_fmode_flags(x) \
+	__print_flags(x, "|", \
+		__fmode_flag(READ), \
+		__fmode_flag(WRITE), \
+		__fmode_flag(EXEC))
+
+#ifdef CONFIG_64BIT
+#define show_fs_fcntl_cmd(x) \
+	__print_symbolic(x, \
+		{ F_DUPFD,		"DUPFD" }, \
+		{ F_GETFD,		"GETFD" }, \
+		{ F_SETFD,		"SETFD" }, \
+		{ F_GETFL,		"GETFL" }, \
+		{ F_SETFL,		"SETFL" }, \
+		{ F_GETLK,		"GETLK" }, \
+		{ F_SETLK,		"SETLK" }, \
+		{ F_SETLKW,		"SETLKW" }, \
+		{ F_SETOWN,		"SETOWN" }, \
+		{ F_GETOWN,		"GETOWN" }, \
+		{ F_SETSIG,		"SETSIG" }, \
+		{ F_GETSIG,		"GETSIG" }, \
+		{ F_SETOWN_EX,		"SETOWN_EX" }, \
+		{ F_GETOWN_EX,		"GETOWN_EX" }, \
+		{ F_GETOWNER_UIDS,	"GETOWNER_UIDS" }, \
+		{ F_OFD_GETLK,		"OFD_GETLK" }, \
+		{ F_OFD_SETLK,		"OFD_SETLK" }, \
+		{ F_OFD_SETLKW,		"OFD_SETLKW" })
+#else /* CONFIG_64BIT */
+#define show_fs_fcntl_cmd(x) \
+	__print_symbolic(x, \
+		{ F_DUPFD,		"DUPFD" }, \
+		{ F_GETFD,		"GETFD" }, \
+		{ F_SETFD,		"SETFD" }, \
+		{ F_GETFL,		"GETFL" }, \
+		{ F_SETFL,		"SETFL" }, \
+		{ F_GETLK,		"GETLK" }, \
+		{ F_SETLK,		"SETLK" }, \
+		{ F_SETLKW,		"SETLKW" }, \
+		{ F_SETOWN,		"SETOWN" }, \
+		{ F_GETOWN,		"GETOWN" }, \
+		{ F_SETSIG,		"SETSIG" }, \
+		{ F_GETSIG,		"GETSIG" }, \
+		{ F_GETLK64,		"GETLK64" }, \
+		{ F_SETLK64,		"SETLK64" }, \
+		{ F_SETLKW64,		"SETLKW64" }, \
+		{ F_SETOWN_EX,		"SETOWN_EX" }, \
+		{ F_GETOWN_EX,		"GETOWN_EX" }, \
+		{ F_GETOWNER_UIDS,	"GETOWNER_UIDS" }, \
+		{ F_OFD_GETLK,		"OFD_GETLK" }, \
+		{ F_OFD_SETLK,		"OFD_SETLK" }, \
+		{ F_OFD_SETLKW,		"OFD_SETLKW" })
+#endif /* CONFIG_64BIT */
+
+#define show_fs_fcntl_lock_type(x) \
+	__print_symbolic(x, \
+		{ F_RDLCK,		"RDLCK" }, \
+		{ F_WRLCK,		"WRLCK" }, \
+		{ F_UNLCK,		"UNLCK" })
+
+#define show_fs_lookup_flags(flags) \
+	__print_flags(flags, "|", \
+		{ LOOKUP_FOLLOW,	"FOLLOW" }, \
+		{ LOOKUP_DIRECTORY,	"DIRECTORY" }, \
+		{ LOOKUP_AUTOMOUNT,	"AUTOMOUNT" }, \
+		{ LOOKUP_EMPTY,		"EMPTY" }, \
+		{ LOOKUP_DOWN,		"DOWN" }, \
+		{ LOOKUP_MOUNTPOINT,	"MOUNTPOINT" }, \
+		{ LOOKUP_REVAL,		"REVAL" }, \
+		{ LOOKUP_RCU,		"RCU" }, \
+		{ LOOKUP_OPEN,		"OPEN" }, \
+		{ LOOKUP_CREATE,	"CREATE" }, \
+		{ LOOKUP_EXCL,		"EXCL" }, \
+		{ LOOKUP_RENAME_TARGET,	"RENAME_TARGET" }, \
+		{ LOOKUP_PARENT,	"PARENT" }, \
+		{ LOOKUP_NO_SYMLINKS,	"NO_SYMLINKS" }, \
+		{ LOOKUP_NO_MAGICLINKS,	"NO_MAGICLINKS" }, \
+		{ LOOKUP_NO_XDEV,	"NO_XDEV" }, \
+		{ LOOKUP_BENEATH,	"BENEATH" }, \
+		{ LOOKUP_IN_ROOT,	"IN_ROOT" }, \
+		{ LOOKUP_CACHED,	"CACHED" })
+
+#define show_ia_valid_flags(flags)			\
+	__print_flags(flags, "|",			\
+		{ ATTR_MODE,		"MODE" },	\
+		{ ATTR_UID,		"UID" },	\
+		{ ATTR_GID,		"GID" },	\
+		{ ATTR_SIZE,		"SIZE" },	\
+		{ ATTR_ATIME,		"ATIME" },	\
+		{ ATTR_MTIME,		"MTIME" },	\
+		{ ATTR_CTIME,		"CTIME" },	\
+		{ ATTR_ATIME_SET,	"ATIME_SET" },	\
+		{ ATTR_MTIME_SET,	"MTIME_SET" },	\
+		{ ATTR_FORCE,		"FORCE" },	\
+		{ ATTR_KILL_SUID,	"KILL_SUID" },	\
+		{ ATTR_KILL_SGID,	"KILL_SGID" },	\
+		{ ATTR_FILE,		"FILE" },	\
+		{ ATTR_KILL_PRIV,	"KILL_PRIV" },	\
+		{ ATTR_OPEN,		"OPEN" },	\
+		{ ATTR_TIMES_SET,	"TIMES_SET" },	\
+		{ ATTR_TOUCH,		"TOUCH"},	\
+		{ ATTR_DELEG,		"DELEG"})
+
+#define show_statx_mask(flags)					\
+	__print_flags(flags, "|",				\
+		{ STATX_TYPE,		"TYPE" },		\
+		{ STATX_MODE,		"MODE" },		\
+		{ STATX_NLINK,		"NLINK" },		\
+		{ STATX_UID,		"UID" },		\
+		{ STATX_GID,		"GID" },		\
+		{ STATX_ATIME,		"ATIME" },		\
+		{ STATX_MTIME,		"MTIME" },		\
+		{ STATX_CTIME,		"CTIME" },		\
+		{ STATX_INO,		"INO" },		\
+		{ STATX_SIZE,		"SIZE" },		\
+		{ STATX_BLOCKS,		"BLOCKS" },		\
+		{ STATX_BASIC_STATS,	"BASIC_STATS" },	\
+		{ STATX_BTIME,		"BTIME" },		\
+		{ STATX_MNT_ID,		"MNT_ID" },		\
+		{ STATX_DIOALIGN,	"DIOALIGN" },		\
+		{ STATX_MNT_ID_UNIQUE,	"MNT_ID_UNIQUE" },	\
+		{ STATX_SUBVOL,		"SUBVOL" },		\
+		{ STATX_WRITE_ATOMIC,	"WRITE_ATOMIC" },	\
+		{ STATX_DIO_READ_ALIGN,	"DIO_READ_ALIGN" })