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, 57 insertions, 0 deletions

diff --git a/sound/hda/controllers/Kconfig b/sound/hda/controllers/Kconfig
new file mode 100644
index 000000000..26ca69b09
--- /dev/null
+++ b/sound/hda/controllers/Kconfig
@@ -0,0 +1,57 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config SND_HDA_INTEL
+	tristate "HD Audio PCI"
+	depends on PCI
+	select SND_HDA
+	select SND_INTEL_DSP_CONFIG
+	help
+	  Say Y here to include support for Intel "High Definition
+	  Audio" (Azalia) and its compatible devices.
+
+	  This option enables the HD-audio controller.  Don't forget
+	  to choose the appropriate HD-audio codec options.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-hda-intel.
+
+config SND_HDA_TEGRA
+	tristate "NVIDIA Tegra HD Audio"
+	depends on ARCH_TEGRA
+	select SND_HDA
+	select SND_HDA_ALIGNED_MMIO
+	help
+	  Say Y here to support the HDA controller present in NVIDIA
+	  Tegra SoCs
+
+	  This options enables support for the HD Audio controller
+	  present in some NVIDIA Tegra SoCs, used to communicate audio
+	  to the HDMI output.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-hda-tegra.
+
+config SND_HDA_CIX_IPBLOQ
+	tristate "CIX IPBLOQ HD Audio"
+	depends on ARCH_CIX || COMPILE_TEST
+	depends on ARCH_DMA_ADDR_T_64BIT
+	select SND_HDA
+	select SND_HDA_ALIGNED_MMIO
+	help
+	  Say Y here to support the HDA controller present in CIX SoCs
+
+	  This options enables support for the HD Audio controller
+	  present in some CIX SoCs.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-hda-cix-ipbloq.
+
+config SND_HDA_ACPI
+	tristate "HD Audio ACPI"
+	depends on ACPI
+	select SND_HDA
+	help
+	  Say Y here to include support for Azalia-compatible HDA controllers
+	  which are advertised via ACPI objects.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-hda-acpi.