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, 33 insertions, 0 deletions

diff --git a/drivers/misc/cardreader/Kconfig b/drivers/misc/cardreader/Kconfig
new file mode 100644
index 000000000..a70700f0e
--- /dev/null
+++ b/drivers/misc/cardreader/Kconfig
@@ -0,0 +1,33 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config MISC_ALCOR_PCI
+	tristate "Alcor Micro/Alcor Link PCI-E card reader"
+	depends on PCI
+	select MFD_CORE
+	help
+	  This supports for Alcor Micro PCI-Express card reader including au6601,
+	  au6621.
+	  Alcor Micro card readers support access to many types of memory cards,
+	  such as Memory Stick, Memory Stick Pro, Secure Digital and
+	  MultiMediaCard.
+
+config MISC_RTSX_PCI
+	tristate "Realtek PCI-E card reader"
+	depends on PCI
+	select MFD_CORE
+	help
+	  This supports for Realtek PCI-Express card reader including rts5209,
+	  rts5227, rts5228, rts522A, rts5229, rts5249, rts524A, rts525A, rtl8411,
+	  rts5260, rts5261, rts5264.
+	  Realtek card readers support access to many types of memory cards,
+	  such as Memory Stick, Memory Stick Pro, Secure Digital and
+	  MultiMediaCard.
+
+config MISC_RTSX_USB
+	tristate "Realtek USB card reader"
+	depends on USB
+	select MFD_CORE
+	help
+	  Select this option to get support for Realtek USB 2.0 card readers
+	  including RTS5129, RTS5139, RTS5179 and RTS5170.
+	  Realtek card reader supports access to many types of memory cards,
+	  such as Memory Stick Pro, Secure Digital and MultiMediaCard.