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, 34 insertions, 0 deletions

diff --git a/drivers/pinctrl/berlin/Kconfig b/drivers/pinctrl/berlin/Kconfig
new file mode 100644
index 000000000..9b1644d1d
--- /dev/null
+++ b/drivers/pinctrl/berlin/Kconfig
@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: GPL-2.0-only
+if (ARCH_BERLIN || COMPILE_TEST)
+
+config PINCTRL_BERLIN
+	bool
+	select PINMUX
+	select REGMAP_MMIO
+
+config PINCTRL_AS370
+	bool "Synaptics as370 pin controller driver"
+	depends on OF
+	select PINCTRL_BERLIN
+
+config PINCTRL_BERLIN_BG2
+	def_bool MACH_BERLIN_BG2
+	depends on OF
+	select PINCTRL_BERLIN
+
+config PINCTRL_BERLIN_BG2CD
+	def_bool MACH_BERLIN_BG2CD
+	depends on OF
+	select PINCTRL_BERLIN
+
+config PINCTRL_BERLIN_BG2Q
+	def_bool MACH_BERLIN_BG2Q
+	depends on OF
+	select PINCTRL_BERLIN
+
+config PINCTRL_BERLIN_BG4CT
+	bool "Marvell berlin4ct pin controller driver"
+	depends on OF
+	select PINCTRL_BERLIN
+
+endif