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, 66 insertions, 0 deletions

diff --git a/sound/soc/codecs/rt-sdw-common.h b/sound/soc/codecs/rt-sdw-common.h
new file mode 100644
index 000000000..4759516fe
--- /dev/null
+++ b/sound/soc/codecs/rt-sdw-common.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+//
+// rt-sdw-common.h
+//
+// Copyright(c) 2024 Realtek Semiconductor Corp.
+//
+
+/*
+ * This file defines common functions used with Realtek soundwire codecs.
+ */
+
+#ifndef __RT_SDW_COMMON_H__
+#define __RT_SDW_COMMON_H__
+
+#define SDCA_NUM_JACK_CODEC			0x01
+#define SDCA_NUM_MIC_ARRAY			0x02
+#define SDCA_NUM_HID				0x03
+#define SDCA_NUM_AMP				0x04
+#define RT_SDCA_CTL_SELECTED_MODE		0x01
+#define RT_SDCA_CTL_DETECTED_MODE		0x02
+#define RT_SDCA_CTL_HIDTX_CURRENT_OWNER		0x10
+#define RT_SDCA_CTL_HIDTX_MESSAGE_OFFSET	0x12
+
+struct rt_sdca_dmic_kctrl_priv {
+	unsigned int reg_base;
+	unsigned int count;
+	unsigned int max;
+	unsigned int invert;
+};
+
+#define RT_SDCA_PR_VALUE(xreg_base, xcount, xmax, xinvert) \
+	((unsigned long)&(struct rt_sdca_dmic_kctrl_priv) \
+		{.reg_base = xreg_base, .count = xcount, .max = xmax, \
+		.invert = xinvert})
+
+#define RT_SDCA_FU_CTRL(xname, reg_base, xmax, xinvert, xcount, \
+	xinfo, xget, xput) \
+{	.iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = (xname), \
+	.info = xinfo, \
+	.get = xget, \
+	.put = xput, \
+	.private_value = RT_SDCA_PR_VALUE(reg_base, xcount, xmax, xinvert)}
+
+#define RT_SDCA_EXT_TLV(xname, reg_base, xhandler_get,\
+	 xhandler_put, xcount, xmax, tlv_array, xinfo) \
+{	.iface = SNDRV_CTL_ELEM_IFACE_MIXER, .name = (xname), \
+	.access = SNDRV_CTL_ELEM_ACCESS_TLV_READ | \
+		 SNDRV_CTL_ELEM_ACCESS_READWRITE, \
+	.tlv.p = (tlv_array), \
+	.info = xinfo, \
+	.get = xhandler_get, .put = xhandler_put, \
+	.private_value = RT_SDCA_PR_VALUE(reg_base, xcount, xmax, 0) }
+
+
+int rt_sdca_index_write(struct regmap *map, unsigned int nid,
+	unsigned int reg, unsigned int value);
+int rt_sdca_index_read(struct regmap *map, unsigned int nid,
+	unsigned int reg, unsigned int *value);
+int rt_sdca_index_update_bits(struct regmap *map,
+	unsigned int nid, unsigned int reg, unsigned int mask, unsigned int val);
+int rt_sdca_btn_type(unsigned char *buffer);
+int rt_sdca_headset_detect(struct regmap *map, unsigned int entity_id);
+int rt_sdca_button_detect(struct regmap *map, unsigned int entity_id,
+	unsigned int hid_buf_addr, unsigned int hid_id);
+
+#endif /* __RT_SDW_COMMON_H__ */