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, 54 insertions, 0 deletions

diff --git a/drivers/mfd/madera.h b/drivers/mfd/madera.h
new file mode 100644
index 000000000..900205678
--- /dev/null
+++ b/drivers/mfd/madera.h
@@ -0,0 +1,54 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * MFD internals for Cirrus Logic Madera codecs
+ *
+ * Copyright 2015-2018 Cirrus Logic
+ */
+
+#ifndef MADERA_MFD_H
+#define MADERA_MFD_H
+
+#include <linux/of.h>
+#include <linux/pm.h>
+
+struct madera;
+
+extern const struct dev_pm_ops madera_pm_ops;
+extern const struct of_device_id madera_of_match[];
+
+int madera_dev_init(struct madera *madera);
+int madera_dev_exit(struct madera *madera);
+
+const char *madera_name_from_type(enum madera_type type);
+
+extern const struct regmap_config cs47l15_16bit_spi_regmap;
+extern const struct regmap_config cs47l15_32bit_spi_regmap;
+extern const struct regmap_config cs47l15_16bit_i2c_regmap;
+extern const struct regmap_config cs47l15_32bit_i2c_regmap;
+int cs47l15_patch(struct madera *madera);
+
+extern const struct regmap_config cs47l35_16bit_spi_regmap;
+extern const struct regmap_config cs47l35_32bit_spi_regmap;
+extern const struct regmap_config cs47l35_16bit_i2c_regmap;
+extern const struct regmap_config cs47l35_32bit_i2c_regmap;
+int cs47l35_patch(struct madera *madera);
+
+extern const struct regmap_config cs47l85_16bit_spi_regmap;
+extern const struct regmap_config cs47l85_32bit_spi_regmap;
+extern const struct regmap_config cs47l85_16bit_i2c_regmap;
+extern const struct regmap_config cs47l85_32bit_i2c_regmap;
+int cs47l85_patch(struct madera *madera);
+
+extern const struct regmap_config cs47l90_16bit_spi_regmap;
+extern const struct regmap_config cs47l90_32bit_spi_regmap;
+extern const struct regmap_config cs47l90_16bit_i2c_regmap;
+extern const struct regmap_config cs47l90_32bit_i2c_regmap;
+int cs47l90_patch(struct madera *madera);
+
+extern const struct regmap_config cs47l92_16bit_spi_regmap;
+extern const struct regmap_config cs47l92_32bit_spi_regmap;
+extern const struct regmap_config cs47l92_16bit_i2c_regmap;
+extern const struct regmap_config cs47l92_32bit_i2c_regmap;
+int cs47l92_patch(struct madera *madera);
+
+#endif