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>

4 files changed, 517 insertions, 0 deletions

diff --git a/Documentation/devicetree/bindings/eeprom/at24.yaml b/Documentation/devicetree/bindings/eeprom/at24.yaml
new file mode 100644
index 000000000..ef88f4692
--- /dev/null
+++ b/Documentation/devicetree/bindings/eeprom/at24.yaml
@@ -0,0 +1,236 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# Copyright 2019 BayLibre SAS
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/eeprom/at24.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: I2C EEPROMs compatible with Atmel's AT24
+
+maintainers:
+  - Bartosz Golaszewski <bgolaszewski@baylibre.com>
+
+allOf:
+  - $ref: /schemas/nvmem/nvmem.yaml
+  - $ref: /schemas/nvmem/nvmem-deprecated-cells.yaml
+
+select:
+  properties:
+    compatible:
+      contains:
+        anyOf:
+          - pattern: "^atmel,(24(c|cs|mac)[0-9]+|spd)$"
+          - enum: ["microchip,24aa025e48", "microchip,24aa025e64"]
+  required:
+    - compatible
+
+properties:
+  $nodename:
+    pattern: "^eeprom@[0-9a-f]{1,2}$"
+
+  # There are multiple known vendors who manufacture EEPROM chips compatible
+  # with Atmel's AT24. The compatible string requires either a single item
+  # if the memory comes from Atmel (in which case the vendor part must be
+  # 'atmel') or two items with the same 'model' part where the vendor part of
+  # the first one is the actual manufacturer and the second item is the
+  # corresponding 'atmel,<model>' from Atmel.
+  compatible:
+    oneOf:
+      - allOf:
+          - minItems: 1
+            items:
+              - pattern: "^(atmel|catalyst|microchip|nxp|ramtron|renesas|rohm|st),(24(c|cs|lc|mac)[0-9]+|spd)$"
+              - pattern: "^atmel,(24(c|cs|mac)[0-9]+|spd)$"
+          - oneOf:
+              - items:
+                  pattern: c00$
+              - items:
+                  pattern: c01$
+              - items:
+                  pattern: cs01$
+              - items:
+                  pattern: c02$
+              - items:
+                  pattern: cs02$
+              - items:
+                  pattern: mac402$
+              - items:
+                  pattern: mac602$
+              - items:
+                  pattern: c04$
+              - items:
+                  pattern: cs04$
+              - items:
+                  pattern: c08$
+              - items:
+                  pattern: cs08$
+              - items:
+                  pattern: c16$
+              - items:
+                  pattern: cs16$
+              - items:
+                  pattern: c32$
+              - items:
+                  pattern: cs32$
+              - items:
+                  pattern: c64$
+              - items:
+                  pattern: cs64$
+              - items:
+                  pattern: c128$
+              - items:
+                  pattern: cs128$
+              - items:
+                  pattern: c256$
+              - items:
+                  pattern: cs256$
+              - items:
+                  pattern: c512$
+              - items:
+                  pattern: cs512$
+              - items:
+                  pattern: c1024$
+              - items:
+                  pattern: cs1024$
+              - items:
+                  pattern: c1025$
+              - items:
+                  pattern: cs1025$
+              - items:
+                  pattern: c2048$
+              - items:
+                  pattern: cs2048$
+              - items:
+                  pattern: spd$
+      # These are special cases that don't conform to the above pattern.
+      # Each requires a standard at24 model as fallback.
+      - items:
+          - enum:
+              - rohm,br24g01
+              - rohm,br24t01
+          - const: atmel,24c01
+      - items:
+          - enum:
+              - nxp,se97b
+              - renesas,r1ex24002
+          - const: atmel,24c02
+      - items:
+          - enum:
+              - belling,bl24c04a
+              - giantec,gt24c04a
+              - onnn,cat24c04
+              - onnn,cat24c05
+              - rohm,br24g04
+          - const: atmel,24c04
+      - items:
+          - enum:
+              - belling,bl24c16a
+              - belling,bl24c16f
+              - renesas,r1ex24016
+          - const: atmel,24c16
+      - items:
+          - const: giantec,gt24c32a
+          - const: atmel,24c32
+      - items:
+          - enum:
+              - belling,bl24s64
+              - giantec,gt24p64a
+              - onnn,n24s64b
+              - puya,p24c64f
+          - const: atmel,24c64
+      - items:
+          - enum:
+              - giantec,gt24p128e
+              - giantec,gt24p128f
+              - puya,p24c128f
+              - renesas,r1ex24128
+              - samsung,s524ad0xd1
+          - const: atmel,24c128
+      - items:
+          - enum:
+              - giantec,gt24c256c
+              - puya,p24c256c
+          - const: atmel,24c256
+      - items:
+          - const: microchip,24aa025e48
+      - items:
+          - const: microchip,24aa025e64
+      - items:
+          - const: st,24256e-wl
+      - pattern: '^atmel,24c(32|64)d-wl$' # Actual vendor is st
+
+  label:
+    description: Descriptive name of the EEPROM.
+
+  reg:
+    maxItems: 1
+
+  pagesize:
+    description:
+      The length of the pagesize for writing. Please consult the
+      manual of your device, that value varies a lot. A wrong value
+      may result in data loss! If not specified, a safety value of
+      '1' is used which will be very slow.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [1, 8, 16, 32, 64, 128, 256]
+    default: 1
+
+  read-only:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description:
+      Disables writes to the eeprom.
+
+  size:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      Total eeprom size in bytes.
+
+  no-read-rollover:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description:
+      Indicates that the multi-address eeprom does not automatically roll
+      over reads to the next slave address. Please consult the manual of
+      your device.
+
+  wp-gpios: true
+
+  address-width:
+    description:
+      Number of address bits.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 8
+    enum: [ 8, 16 ]
+
+  num-addresses:
+    description:
+      Total number of i2c slave addresses this device takes.
+    $ref: /schemas/types.yaml#/definitions/uint32
+    default: 1
+    minimum: 1
+    maximum: 8
+
+  vcc-supply:
+    description:
+      phandle of the regulator that provides the supply voltage.
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      eeprom@52 {
+          compatible = "microchip,24c32", "atmel,24c32";
+          reg = <0x52>;
+          pagesize = <32>;
+          wp-gpios = <&gpio1 3 0>;
+          num-addresses = <8>;
+      };
+    };
+...
diff --git a/Documentation/devicetree/bindings/eeprom/at25.yaml b/Documentation/devicetree/bindings/eeprom/at25.yaml
new file mode 100644
index 000000000..bb78e12b8
--- /dev/null
+++ b/Documentation/devicetree/bindings/eeprom/at25.yaml
@@ -0,0 +1,159 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/eeprom/at25.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: SPI EEPROMs or FRAMs compatible with Atmel's AT25
+
+maintainers:
+  - Christian Eggers <ceggers@arri.de>
+
+properties:
+  $nodename:
+    anyOf:
+      - pattern: "^eeprom@[0-9a-f]{1,2}$"
+      - pattern: "^fram@[0-9a-f]{1,2}$"
+
+  # There are multiple known vendors who manufacture EEPROM chips compatible
+  # with Atmel's AT25. The compatible string requires two items where the
+  # 'vendor' and 'model' parts of the first are the actual chip and the second
+  # item is fixed to "atmel,at25". Some existing bindings only have the
+  # "atmel,at25" part and should be fixed by somebody who knows vendor and
+  # product.
+  compatible:
+    oneOf:
+      - items:
+          - enum:
+              - anvo,anv32c81w
+              - anvo,anv32e61w
+              - atmel,at25256B
+              - fujitsu,mb85rs1mt
+              - fujitsu,mb85rs256
+              - fujitsu,mb85rs64
+              - microchip,25aa010a
+              - microchip,at25160bn
+              - microchip,25lc040
+              - st,m95m02
+              - st,m95256
+              - st,m95640
+              - cypress,fm25
+
+          - const: atmel,at25
+
+      # Please don't use this alternative for new bindings.
+      - items:
+          - const: atmel,at25
+
+  reg:
+    maxItems: 1
+
+  pagesize:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [1, 8, 16, 32, 64, 128, 256, 512, 1024, 2048, 4096, 8192, 16384, 32768, 65536, 131072]
+    description:
+      Size of the eeprom page. FRAMs don't have pages.
+
+  size:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      Total eeprom size in bytes.
+      Also used for FRAMs without device ID where the size cannot be detected.
+
+  address-width:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [ 8, 9, 16, 24 ]
+    description:
+      Number of address bits.
+      For 9 bits, the MSB of the address is sent as bit 3 of the instruction
+      byte, before the address byte.
+
+  spi-cpha: true
+
+  spi-cpol: true
+
+  read-only:
+    description:
+      Disable writes to the eeprom.
+    type: boolean
+
+  wp-gpios:
+    maxItems: 1
+    description:
+      GPIO to which the write-protect pin of the chip is connected.
+
+  # Deprecated: at25,byte-len, at25,addr-mode, at25,page-size
+  at25,byte-len:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      Total eeprom size in bytes. Deprecated, use "size" property instead.
+    deprecated: true
+
+  at25,addr-mode:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      Addr-mode flags, as defined in include/linux/spi/eeprom.h.
+      Deprecated, use "address-width" property instead.
+    deprecated: true
+
+  at25,page-size:
+    $ref: /schemas/types.yaml#/definitions/uint32
+    description:
+      Size of the eeprom page. Deprecated, use "pagesize" property instead.
+    deprecated: true
+
+required:
+  - compatible
+  - reg
+  - spi-max-frequency
+
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+  - $ref: /schemas/nvmem/nvmem.yaml
+  - if:
+      properties:
+        compatible:
+          not:
+            contains:
+              const: cypress,fm25
+    then:
+      required:
+        - pagesize
+        - size
+        - address-width
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+    spi {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        eeprom@0 {
+            compatible = "st,m95256", "atmel,at25";
+            reg = <0>;
+            spi-max-frequency = <5000000>;
+            spi-cpha;
+            spi-cpol;
+            wp-gpios = <&gpio1 3 0>;
+
+            pagesize = <64>;
+            size = <32768>;
+            address-width = <16>;
+        };
+
+        fram@1 {
+            compatible = "cypress,fm25", "atmel,at25";
+            reg = <1>;
+            spi-max-frequency = <40000000>;
+        };
+
+        fram@2 {
+            compatible = "cypress,fm25", "atmel,at25";
+            reg = <2>;
+            spi-max-frequency = <20000000>;
+            size = <2048>;
+        };
+    };
diff --git a/Documentation/devicetree/bindings/eeprom/microchip,93lc46b.yaml b/Documentation/devicetree/bindings/eeprom/microchip,93lc46b.yaml
new file mode 100644
index 000000000..144e86ce5
--- /dev/null
+++ b/Documentation/devicetree/bindings/eeprom/microchip,93lc46b.yaml
@@ -0,0 +1,70 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/eeprom/microchip,93lc46b.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Microchip 93xx46 SPI compatible EEPROM family
+
+maintainers:
+  - Cory Tusar <cory.tusar@pid1solutions.com>
+
+properties:
+  compatible:
+    enum:
+      - atmel,at93c46
+      - atmel,at93c46d
+      - atmel,at93c56
+      - atmel,at93c66
+      - eeprom-93xx46
+      - microchip,93lc46b
+
+  data-size:
+    description: number of data bits per word
+    $ref: /schemas/types.yaml#/definitions/uint32
+    enum: [8, 16]
+
+  reg:
+    description: chip select of EEPROM
+    maxItems: 1
+
+  read-only:
+    description:
+      parameter-less property which disables writes to the EEPROM
+    type: boolean
+
+  select-gpios:
+    description:
+      specifies the GPIO that needs to be asserted prior to each access
+      of EEPROM (e.g. for SPI bus multiplexing)
+    maxItems: 1
+
+required:
+  - compatible
+  - reg
+  - data-size
+  - spi-max-frequency
+
+allOf:
+  - $ref: /schemas/spi/spi-peripheral-props.yaml#
+  - $ref: /schemas/nvmem/nvmem.yaml
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    spi {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      eeprom@0 {
+        compatible = "eeprom-93xx46";
+        reg = <0>;
+        spi-max-frequency = <1000000>;
+        spi-cs-high;
+        data-size = <8>;
+        select-gpios = <&gpio4 4 GPIO_ACTIVE_HIGH>;
+      };
+    };
diff --git a/Documentation/devicetree/bindings/eeprom/st,m24lr.yaml b/Documentation/devicetree/bindings/eeprom/st,m24lr.yaml
new file mode 100644
index 000000000..0a0820e9d
--- /dev/null
+++ b/Documentation/devicetree/bindings/eeprom/st,m24lr.yaml
@@ -0,0 +1,52 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/eeprom/st,m24lr.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: STMicroelectronics M24LR NFC/RFID EEPROM
+
+maintainers:
+  - Abd-Alrhman Masalkhi <abd.masalkhi@gmail.com>
+
+description:
+  STMicroelectronics M24LR series are dual-interface (RF + I2C)
+  EEPROM chips. These devices support I2C-based access to both
+  memory and a system area that controls authentication and configuration.
+  They expose two I2C addresses, one for the system parameter sector and
+  one for the EEPROM.
+
+allOf:
+  - $ref: /schemas/nvmem/nvmem.yaml#
+
+properties:
+  compatible:
+    enum:
+      - st,m24lr04e-r
+      - st,m24lr16e-r
+      - st,m24lr64e-r
+
+  reg:
+    items:
+      - description: I2C address used for control/system registers
+      - description: I2C address used for EEPROM memory access
+
+required:
+  - compatible
+  - reg
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    i2c {
+      #address-cells = <1>;
+      #size-cells = <0>;
+
+      eeprom@57 {
+        compatible = "st,m24lr04e-r";
+        reg = <0x57>, /* primary-device */
+              <0x53>; /* secondary-device */
+      };
+    };
+...