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, 193 insertions, 0 deletions

diff --git a/samples/rust/Kconfig b/samples/rust/Kconfig
new file mode 100644
index 000000000..31d62533e
--- /dev/null
+++ b/samples/rust/Kconfig
@@ -0,0 +1,193 @@
+# SPDX-License-Identifier: GPL-2.0
+
+menuconfig SAMPLES_RUST
+	bool "Rust samples"
+	depends on RUST
+	help
+	  You can build sample Rust kernel code here.
+
+	  If unsure, say N.
+
+if SAMPLES_RUST
+
+config SAMPLE_RUST_CONFIGFS
+	tristate "Configfs sample"
+	depends on CONFIGFS_FS
+	help
+	  This option builds the Rust configfs sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_configfs.
+
+	  If unsure, say N.
+
+config SAMPLE_RUST_MINIMAL
+	tristate "Minimal"
+	help
+	  This option builds the Rust minimal module sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_minimal.
+
+	  If unsure, say N.
+
+config SAMPLE_RUST_MISC_DEVICE
+	tristate "Misc device"
+	help
+	  This option builds the Rust misc device.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_misc_device.
+
+	  If unsure, say N.
+
+config SAMPLE_RUST_PRINT
+	tristate "Printing macros"
+	help
+	  This option builds the Rust printing macros sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_print.
+
+	  If unsure, say N.
+
+config SAMPLE_RUST_DMA
+	tristate "DMA Test Driver"
+	depends on PCI
+	help
+	  This option builds the Rust DMA Test driver sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_dma.
+
+	  If unsure, say N.
+
+config SAMPLE_RUST_DEBUGFS
+	tristate "DebugFS Test Module"
+	depends on DEBUG_FS
+	help
+	  This option builds the Rust DebugFS Test module sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_debugfs.
+
+	  If unsure, say N.
+
+config SAMPLE_RUST_DEBUGFS_SCOPED
+	tristate "Scoped DebugFS Test Module"
+	depends on DEBUG_FS
+	help
+	  This option builds the Rust Scoped DebugFS Test module sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_debugfs_scoped.
+
+	  If unsure, say N.
+
+config SAMPLE_RUST_DRIVER_I2C
+	tristate "I2C Driver"
+	depends on I2C=y
+	help
+	  This option builds the Rust I2C driver sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_driver_i2c.
+
+	  If unsure, say N.
+
+config SAMPLE_RUST_I2C_CLIENT
+	tristate "I2C Client Registration"
+	depends on I2C=y
+	help
+	  This option builds the Rust I2C client manual creation
+	  sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_i2c_client.
+
+	  If unsure, say N.
+
+config SAMPLE_RUST_DRIVER_PCI
+	tristate "PCI Driver"
+	depends on PCI
+	help
+	  This option builds the Rust PCI driver sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_driver_pci.
+
+	  If unsure, say N.
+
+config SAMPLE_RUST_DRIVER_PLATFORM
+	tristate "Platform Driver"
+	help
+	  This option builds the Rust Platform driver sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_driver_platform.
+
+	  If unsure, say N.
+
+config SAMPLE_RUST_DRIVER_USB
+	tristate "USB Driver"
+	depends on USB = y
+	help
+	  This option builds the Rust USB driver sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_driver_usb.
+
+	  If unsure, say N.
+
+config SAMPLE_RUST_DRIVER_FAUX
+	tristate "Faux Driver"
+	help
+	  This option builds the Rust Faux driver sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_driver_faux.
+
+	  If unsure, say N.
+
+config SAMPLE_RUST_DRIVER_AUXILIARY
+	tristate "Auxiliary Driver"
+	depends on PCI
+	select AUXILIARY_BUS
+	help
+	  This option builds the Rust auxiliary driver sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_driver_auxiliary.
+
+	  If unsure, say N.
+
+config SAMPLE_RUST_DRIVER_SERDEV
+	tristate "Serial Device Bus Device Driver"
+	select RUST_SERIAL_DEV_BUS_ABSTRACTIONS
+	help
+	  This option builds the Rust serial device bus driver sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_driver_serdev.
+
+	  If unsure, say N.
+
+config SAMPLE_RUST_SOC
+	tristate "SoC Driver"
+	select SOC_BUS
+	help
+	  This option builds the Rust SoC driver sample.
+
+	  To compile this as a module, choose M here:
+	  the module will be called rust_soc.
+
+	  If unsure, say N.
+
+config SAMPLE_RUST_HOSTPROGS
+	bool "Host programs"
+	help
+	  This option builds the Rust host program samples.
+
+	  If unsure, say N.
+
+endif # SAMPLES_RUST