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, 73 insertions, 0 deletions

diff --git a/drivers/net/fddi/Kconfig b/drivers/net/fddi/Kconfig
new file mode 100644
index 000000000..846bf41c2
--- /dev/null
+++ b/drivers/net/fddi/Kconfig
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# FDDI network device configuration
+#
+
+config FDDI
+	tristate "FDDI driver support"
+	depends on PCI || EISA || TC
+	help
+	  Fiber Distributed Data Interface is a high speed local area network
+	  design; essentially a replacement for high speed Ethernet. FDDI can
+	  run over copper or fiber. If you are connected to such a network and
+	  want a driver for the FDDI card in your computer, say Y here (and
+	  then also Y to the driver for your FDDI card, below). Most people
+	  will say N.
+
+if FDDI
+
+config DEFZA
+	tristate "DEC FDDIcontroller 700/700-C (DEFZA-xx) support"
+	depends on FDDI && TC
+	help
+	  This is support for the DEC FDDIcontroller 700 (DEFZA-AA, fiber)
+	  and 700-C (DEFZA-CA, copper) TURBOchannel network cards which
+	  can connect you to a local FDDI network.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called defza.  If unsure, say N.
+
+config DEFXX
+	tristate "Digital DEFTA/DEFEA/DEFPA adapter support"
+	depends on FDDI && (PCI || EISA || TC)
+	help
+	  This is support for the DIGITAL series of TURBOchannel (DEFTA),
+	  EISA (DEFEA) and PCI (DEFPA) controllers which can connect you
+	  to a local FDDI network.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called defxx.  If unsure, say N.
+
+config SKFP
+	tristate "SysKonnect FDDI PCI support"
+	depends on FDDI && PCI
+	select BITREVERSE
+	help
+	  Say Y here if you have a SysKonnect FDDI PCI adapter.
+	  The following adapters are supported by this driver:
+	  - SK-5521 (SK-NET FDDI-UP)
+	  - SK-5522 (SK-NET FDDI-UP DAS)
+	  - SK-5541 (SK-NET FDDI-FP)
+	  - SK-5543 (SK-NET FDDI-LP)
+	  - SK-5544 (SK-NET FDDI-LP DAS)
+	  - SK-5821 (SK-NET FDDI-UP64)
+	  - SK-5822 (SK-NET FDDI-UP64 DAS)
+	  - SK-5841 (SK-NET FDDI-FP64)
+	  - SK-5843 (SK-NET FDDI-LP64)
+	  - SK-5844 (SK-NET FDDI-LP64 DAS)
+	  - Netelligent 100 FDDI DAS Fibre SC
+	  - Netelligent 100 FDDI SAS Fibre SC
+	  - Netelligent 100 FDDI DAS UTP
+	  - Netelligent 100 FDDI SAS UTP
+	  - Netelligent 100 FDDI SAS Fibre MIC
+
+	  Read <file:Documentation/networking/device_drivers/fddi/skfp.rst>
+	  for information about the driver.
+
+	  Questions concerning this driver can be addressed to:
+	  <linux@syskonnect.de>
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called skfp.  This is recommended.
+
+endif # FDDI