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, 46 insertions, 0 deletions

diff --git a/sound/soc/codecs/wcd-common.h b/sound/soc/codecs/wcd-common.h
new file mode 100644
index 000000000..d5c156e64
--- /dev/null
+++ b/sound/soc/codecs/wcd-common.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (c) 2025, Qualcomm Technologies, Inc. and/or its subsidiaries.
+ */
+
+#ifndef __WCD_COMMON_H__
+#define __WCD_COMMON_H__
+
+struct device;
+struct sdw_slave;
+struct sdw_bus_params;
+struct irq_domain;
+enum sdw_slave_status;
+
+#define WCD_MAX_MICBIAS		4
+
+struct wcd_sdw_ch_info {
+	int port_num;
+	unsigned int ch_mask;
+	unsigned int master_ch_mask;
+};
+
+#define WCD_SDW_CH(id, pn, cmask)	\
+	[id] = {			\
+		.port_num = pn,		\
+		.ch_mask = cmask,	\
+		.master_ch_mask = cmask,	\
+	}
+
+struct wcd_common {
+	struct device *dev;
+	int max_bias;
+	u32 micb_mv[WCD_MAX_MICBIAS];
+	u32 micb_vout[WCD_MAX_MICBIAS];
+};
+
+extern const struct component_ops wcd_sdw_component_ops;
+int wcd_get_micb_vout_ctl_val(struct device *dev, u32 micb_mv);
+int wcd_dt_parse_micbias_info(struct wcd_common *common);
+int wcd_update_status(struct sdw_slave *slave, enum sdw_slave_status status);
+int wcd_bus_config(struct sdw_slave *slave, struct sdw_bus_params *params);
+int wcd_interrupt_callback(struct sdw_slave *slave, struct irq_domain *slave_irq,
+		unsigned int wcd_intr_status0, unsigned int wcd_intr_status1,
+		unsigned int wcd_intr_status2);
+
+#endif /* __WCD_COMMON_H__  */