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, 64 insertions, 0 deletions

diff --git a/drivers/dma/ti/Kconfig b/drivers/dma/ti/Kconfig
new file mode 100644
index 000000000..cbc30ab62
--- /dev/null
+++ b/drivers/dma/ti/Kconfig
@@ -0,0 +1,64 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Texas Instruments DMA drivers
+#
+
+config TI_CPPI41
+	tristate "Texas Instruments CPPI 4.1 DMA support"
+	depends on (ARCH_OMAP || ARCH_DAVINCI_DA8XX)
+	select DMA_ENGINE
+	help
+	  The Communications Port Programming Interface (CPPI) 4.1 DMA engine
+	  is currently used by the USB driver on AM335x and DA8xx platforms.
+
+config TI_EDMA
+	tristate "Texas Instruments EDMA support"
+	depends on ARCH_DAVINCI || ARCH_OMAP || ARCH_KEYSTONE || COMPILE_TEST
+	select DMA_ENGINE
+	select DMA_VIRTUAL_CHANNELS
+	select TI_DMA_CROSSBAR if (ARCH_OMAP || COMPILE_TEST)
+	default ARCH_DAVINCI || ARCH_OMAP || ARCH_KEYSTONE
+	help
+	  Enable support for the TI EDMA (Enhanced DMA) controller. This DMA
+	  engine is found on TI DaVinci, AM33xx, AM43xx, DRA7xx and Keystone 2
+	  parts.
+
+config DMA_OMAP
+	tristate "Texas Instruments sDMA (omap-dma) support"
+	depends on ARCH_OMAP || COMPILE_TEST
+	select DMA_ENGINE
+	select DMA_VIRTUAL_CHANNELS
+	select TI_DMA_CROSSBAR if (SOC_DRA7XX || COMPILE_TEST)
+	default ARCH_OMAP
+	help
+	  Enable support for the TI sDMA (System DMA or DMA4) controller. This
+	  DMA engine is found on OMAP and DRA7xx parts.
+
+config TI_K3_UDMA
+	tristate "Texas Instruments UDMA support"
+	depends on ARCH_K3 || COMPILE_TEST
+	depends on TI_SCI_PROTOCOL
+	depends on TI_SCI_INTA_IRQCHIP
+	select DMA_ENGINE
+	select DMA_VIRTUAL_CHANNELS
+	select SOC_TI
+	select TI_K3_RINGACC
+	select TI_K3_PSIL
+        help
+	  Enable support for the TI UDMA (Unified DMA) controller. This
+	  DMA engine is used in AM65x and j721e.
+
+config TI_K3_UDMA_GLUE_LAYER
+	tristate "Texas Instruments UDMA Glue layer for non DMAengine users"
+	depends on ARCH_K3 || COMPILE_TEST
+	depends on TI_K3_UDMA
+	help
+	  Say y here to support the K3 NAVSS DMA glue interface
+	  If unsure, say N.
+
+config TI_K3_PSIL
+       tristate
+       default TI_K3_UDMA
+
+config TI_DMA_CROSSBAR
+	bool