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, 77 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/chrome/google,cros-ec-typec.yaml b/Documentation/devicetree/bindings/chrome/google,cros-ec-typec.yaml
new file mode 100644
index 000000000..fd1a45987
--- /dev/null
+++ b/Documentation/devicetree/bindings/chrome/google,cros-ec-typec.yaml
@@ -0,0 +1,77 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/chrome/google,cros-ec-typec.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Google Chrome OS EC(Embedded Controller) Type C port driver.
+
+maintainers:
+  - Benson Leung <bleung@chromium.org>
+  - Abhishek Pandit-Subedi <abhishekpandit@chromium.org>
+  - Andrei Kuchynski <akuchynski@chromium.org>
+  - Łukasz Bartosik <ukaszb@chromium.org>
+  - Jameson Thies <jthies@google.com>
+
+description:
+  Chrome OS devices have an Embedded Controller(EC) which has access to
+  Type C port state. This node is intended to allow the host to read and
+  control the Type C ports. This binding is compatible with both the
+  cros-ec-typec and cros-ec-ucsi drivers. The cros-ec-typec driver
+  supports the host command interface used by the Chrome OS EC with a
+  built-in Type-C port manager and external Type-C Port Controller
+  (TCPC). The cros-ec-ucsi driver supports the USB Type-C Connector
+  System Software (UCSI) interface used by the Chrome OS EC when the
+  platform has a separate power delivery controller (PDC). The node for
+  this device should be under a cros-ec node like google,cros-ec-spi.
+
+properties:
+  compatible:
+    enum:
+      - google,cros-ec-typec
+      - google,cros-ec-ucsi
+
+  '#address-cells':
+    const: 1
+
+  '#size-cells':
+    const: 0
+
+patternProperties:
+  '^connector@[0-9a-f]+$':
+    $ref: /schemas/connector/usb-connector.yaml#
+    required:
+      - reg
+
+required:
+  - compatible
+
+additionalProperties: false
+
+examples:
+  - |+
+    spi {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      cros_ec: ec@0 {
+        compatible = "google,cros-ec-spi";
+        reg = <0>;
+        interrupts = <35 0>;
+
+        typec {
+          compatible = "google,cros-ec-typec";
+
+          #address-cells = <1>;
+          #size-cells = <0>;
+
+          connector@0 {
+            compatible = "usb-c-connector";
+            reg = <0>;
+            power-role = "dual";
+            data-role = "dual";
+            try-power-role = "source";
+          };
+        };
+      };
+    };