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, 53 insertions, 0 deletions

diff --git a/sound/ppc/Kconfig b/sound/ppc/Kconfig
new file mode 100644
index 000000000..8789cb503
--- /dev/null
+++ b/sound/ppc/Kconfig
@@ -0,0 +1,53 @@
+# SPDX-License-Identifier: GPL-2.0-only
+# ALSA PowerMac drivers
+
+menuconfig SND_PPC
+	bool "PowerPC sound devices"
+	depends on PPC
+	default y
+	help
+	  Support for sound devices specific to PowerPC architectures.
+
+if SND_PPC
+
+config SND_POWERMAC
+	tristate "PowerMac (AWACS, DACA, Burgundy, Tumbler, Keywest)"
+	depends on I2C && INPUT && PPC_PMAC
+	select SND_PCM
+	select SND_VMASTER
+	help
+	  Say Y here to include support for the integrated sound device.
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd-powermac.
+
+config SND_POWERMAC_AUTO_DRC
+	bool "Toggle DRC automatically at headphone/line plug-in"
+	depends on SND_POWERMAC
+	default y
+	help
+	  Say Y here to enable the automatic toggle of DRC (dynamic
+	  range compression) on Tumbler/Snapper.
+	  If this feature is enabled, DRC is turned off when the
+	  headphone/line jack is plugged, and turned on when unplugged.
+
+	  Note that you can turn on/off DRC manually even without this
+	  option.
+
+config SND_PS3
+	tristate "PS3 Audio support"
+	depends on PS3_PS3AV
+	select SND_PCM
+	default m
+	help
+	  Say Y here to include support for audio on the PS3
+
+	  To compile this driver as a module, choose M here: the module
+	  will be called snd_ps3.
+
+config SND_PS3_DEFAULT_START_DELAY
+	int "Startup delay time in ms"
+	depends on SND_PS3
+	default "2000"
+
+endif	# SND_PPC