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, 249 insertions, 0 deletions

diff --git a/net/mac80211/debug.h b/net/mac80211/debug.h
new file mode 100644
index 000000000..ef7c1a68d
--- /dev/null
+++ b/net/mac80211/debug.h
@@ -0,0 +1,249 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Portions
+ * Copyright (C) 2022 - 2025 Intel Corporation
+ */
+#ifndef __MAC80211_DEBUG_H
+#define __MAC80211_DEBUG_H
+#include <linux/once_lite.h>
+#include <net/cfg80211.h>
+
+#ifdef CONFIG_MAC80211_OCB_DEBUG
+#define MAC80211_OCB_DEBUG 1
+#else
+#define MAC80211_OCB_DEBUG 0
+#endif
+
+#ifdef CONFIG_MAC80211_IBSS_DEBUG
+#define MAC80211_IBSS_DEBUG 1
+#else
+#define MAC80211_IBSS_DEBUG 0
+#endif
+
+#ifdef CONFIG_MAC80211_PS_DEBUG
+#define MAC80211_PS_DEBUG 1
+#else
+#define MAC80211_PS_DEBUG 0
+#endif
+
+#ifdef CONFIG_MAC80211_HT_DEBUG
+#define MAC80211_HT_DEBUG 1
+#else
+#define MAC80211_HT_DEBUG 0
+#endif
+
+#ifdef CONFIG_MAC80211_MPL_DEBUG
+#define MAC80211_MPL_DEBUG 1
+#else
+#define MAC80211_MPL_DEBUG 0
+#endif
+
+#ifdef CONFIG_MAC80211_MPATH_DEBUG
+#define MAC80211_MPATH_DEBUG 1
+#else
+#define MAC80211_MPATH_DEBUG 0
+#endif
+
+#ifdef CONFIG_MAC80211_MHWMP_DEBUG
+#define MAC80211_MHWMP_DEBUG 1
+#else
+#define MAC80211_MHWMP_DEBUG 0
+#endif
+
+#ifdef CONFIG_MAC80211_MESH_SYNC_DEBUG
+#define MAC80211_MESH_SYNC_DEBUG 1
+#else
+#define MAC80211_MESH_SYNC_DEBUG 0
+#endif
+
+#ifdef CONFIG_MAC80211_MESH_CSA_DEBUG
+#define MAC80211_MESH_CSA_DEBUG 1
+#else
+#define MAC80211_MESH_CSA_DEBUG 0
+#endif
+
+#ifdef CONFIG_MAC80211_MESH_PS_DEBUG
+#define MAC80211_MESH_PS_DEBUG 1
+#else
+#define MAC80211_MESH_PS_DEBUG 0
+#endif
+
+#ifdef CONFIG_MAC80211_TDLS_DEBUG
+#define MAC80211_TDLS_DEBUG 1
+#else
+#define MAC80211_TDLS_DEBUG 0
+#endif
+
+#ifdef CONFIG_MAC80211_STA_DEBUG
+#define MAC80211_STA_DEBUG 1
+#else
+#define MAC80211_STA_DEBUG 0
+#endif
+
+#ifdef CONFIG_MAC80211_MLME_DEBUG
+#define MAC80211_MLME_DEBUG 1
+#else
+#define MAC80211_MLME_DEBUG 0
+#endif
+
+#ifdef CONFIG_MAC80211_MESSAGE_TRACING
+void __sdata_info(const char *fmt, ...) __printf(1, 2);
+void __sdata_dbg(bool print, const char *fmt, ...) __printf(2, 3);
+void __sdata_err(const char *fmt, ...) __printf(1, 2);
+void __wiphy_dbg(struct wiphy *wiphy, bool print, const char *fmt, ...)
+	__printf(3, 4);
+
+#define _sdata_info(sdata, fmt, ...)					\
+	__sdata_info("%s: " fmt, (sdata)->name, ##__VA_ARGS__)
+#define _sdata_dbg(print, sdata, fmt, ...)				\
+	__sdata_dbg(print, "%s: " fmt, (sdata)->name, ##__VA_ARGS__)
+#define _sdata_err(sdata, fmt, ...)					\
+	__sdata_err("%s: " fmt, (sdata)->name, ##__VA_ARGS__)
+#define _wiphy_dbg(print, wiphy, fmt, ...)				\
+	__wiphy_dbg(wiphy, print, fmt, ##__VA_ARGS__)
+#else
+#define _sdata_info(sdata, fmt, ...)					\
+do {									\
+	pr_info("%s: " fmt,						\
+		(sdata)->name, ##__VA_ARGS__);				\
+} while (0)
+
+#define _sdata_dbg(print, sdata, fmt, ...)				\
+do {									\
+	if (print)							\
+		pr_debug("%s: " fmt,					\
+			 (sdata)->name, ##__VA_ARGS__);			\
+} while (0)
+
+#define _sdata_err(sdata, fmt, ...)					\
+do {									\
+	pr_err("%s: " fmt,						\
+	       (sdata)->name, ##__VA_ARGS__);				\
+} while (0)
+
+#define _wiphy_dbg(print, wiphy, fmt, ...)				\
+do {									\
+	if (print)							\
+		wiphy_dbg((wiphy), fmt, ##__VA_ARGS__);			\
+} while (0)
+#endif
+
+#define sdata_info(sdata, fmt, ...)					\
+	_sdata_info(sdata, fmt, ##__VA_ARGS__)
+#define sdata_err(sdata, fmt, ...)					\
+	_sdata_err(sdata, fmt, ##__VA_ARGS__)
+#define sdata_dbg(sdata, fmt, ...)					\
+	_sdata_dbg(1, sdata, fmt, ##__VA_ARGS__)
+
+#define link_info(link, fmt, ...)					\
+	do {								\
+		if (ieee80211_vif_is_mld(&(link)->sdata->vif))          \
+			_sdata_info((link)->sdata, "[link %d] " fmt,	\
+				    (link)->link_id,			\
+				    ##__VA_ARGS__);			\
+		else							\
+			_sdata_info((link)->sdata, fmt, ##__VA_ARGS__);	\
+	} while (0)
+#define link_err(link, fmt, ...)					\
+	do {								\
+		if (ieee80211_vif_is_mld(&(link)->sdata->vif))          \
+			_sdata_err((link)->sdata, "[link %d] " fmt,	\
+				   (link)->link_id,			\
+				   ##__VA_ARGS__);			\
+		else							\
+			_sdata_err((link)->sdata, fmt, ##__VA_ARGS__);	\
+	} while (0)
+#define link_err_once(link, fmt, ...)					\
+	DO_ONCE_LITE(link_err, link, fmt, ##__VA_ARGS__)
+#define link_id_info(sdata, link_id, fmt, ...)				\
+	do {								\
+		if (ieee80211_vif_is_mld(&sdata->vif))			\
+			_sdata_info(sdata, "[link %d] " fmt, link_id,	\
+				    ##__VA_ARGS__);			\
+		else							\
+			_sdata_info(sdata, fmt, ##__VA_ARGS__);		\
+	} while (0)
+#define _link_id_dbg(print, sdata, link_id, fmt, ...)			\
+	do {								\
+		if (ieee80211_vif_is_mld(&(sdata)->vif))		\
+			_sdata_dbg(print, sdata, "[link %d] " fmt,	\
+				   link_id, ##__VA_ARGS__);		\
+		else							\
+			_sdata_dbg(print, sdata, fmt, ##__VA_ARGS__);	\
+	} while (0)
+#define link_dbg(link, fmt, ...)					\
+	_link_id_dbg(1, (link)->sdata, (link)->link_id,			\
+		     fmt, ##__VA_ARGS__)
+
+#define ht_dbg(sdata, fmt, ...)						\
+	_sdata_dbg(MAC80211_HT_DEBUG,					\
+		   sdata, fmt, ##__VA_ARGS__)
+
+#define ht_dbg_ratelimited(sdata, fmt, ...)				\
+	_sdata_dbg(MAC80211_HT_DEBUG && net_ratelimit(),		\
+		   sdata, fmt, ##__VA_ARGS__)
+
+#define ocb_dbg(sdata, fmt, ...)					\
+	_sdata_dbg(MAC80211_OCB_DEBUG,					\
+		   sdata, fmt, ##__VA_ARGS__)
+
+#define ibss_dbg(sdata, fmt, ...)					\
+	_sdata_dbg(MAC80211_IBSS_DEBUG,					\
+		   sdata, fmt, ##__VA_ARGS__)
+
+#define ps_dbg(sdata, fmt, ...)						\
+	_sdata_dbg(MAC80211_PS_DEBUG,					\
+		   sdata, fmt, ##__VA_ARGS__)
+
+#define ps_dbg_hw(hw, fmt, ...)						\
+	_wiphy_dbg(MAC80211_PS_DEBUG,					\
+		   (hw)->wiphy, fmt, ##__VA_ARGS__)
+
+#define ps_dbg_ratelimited(sdata, fmt, ...)				\
+	_sdata_dbg(MAC80211_PS_DEBUG && net_ratelimit(),		\
+		   sdata, fmt, ##__VA_ARGS__)
+
+#define mpl_dbg(sdata, fmt, ...)					\
+	_sdata_dbg(MAC80211_MPL_DEBUG,					\
+		   sdata, fmt, ##__VA_ARGS__)
+
+#define mpath_dbg(sdata, fmt, ...)					\
+	_sdata_dbg(MAC80211_MPATH_DEBUG,				\
+		   sdata, fmt, ##__VA_ARGS__)
+
+#define mhwmp_dbg(sdata, fmt, ...)					\
+	_sdata_dbg(MAC80211_MHWMP_DEBUG,				\
+		   sdata, fmt, ##__VA_ARGS__)
+
+#define msync_dbg(sdata, fmt, ...)					\
+	_sdata_dbg(MAC80211_MESH_SYNC_DEBUG,				\
+		   sdata, fmt, ##__VA_ARGS__)
+
+#define mcsa_dbg(sdata, fmt, ...)					\
+	_sdata_dbg(MAC80211_MESH_CSA_DEBUG,				\
+		   sdata, fmt, ##__VA_ARGS__)
+
+#define mps_dbg(sdata, fmt, ...)					\
+	_sdata_dbg(MAC80211_MESH_PS_DEBUG,				\
+		   sdata, fmt, ##__VA_ARGS__)
+
+#define tdls_dbg(sdata, fmt, ...)					\
+	_sdata_dbg(MAC80211_TDLS_DEBUG,					\
+		   sdata, fmt, ##__VA_ARGS__)
+
+#define sta_dbg(sdata, fmt, ...)					\
+	_sdata_dbg(MAC80211_STA_DEBUG,					\
+		   sdata, fmt, ##__VA_ARGS__)
+
+#define mlme_dbg(sdata, fmt, ...)					\
+	_sdata_dbg(MAC80211_MLME_DEBUG,					\
+		   sdata, fmt, ##__VA_ARGS__)
+#define mlme_link_id_dbg(sdata, link_id, fmt, ...)			\
+	_link_id_dbg(MAC80211_MLME_DEBUG, sdata, link_id,		\
+		     fmt, ##__VA_ARGS__)
+
+#define mlme_dbg_ratelimited(sdata, fmt, ...)				\
+	_sdata_dbg(MAC80211_MLME_DEBUG && net_ratelimit(),		\
+		   sdata, fmt, ##__VA_ARGS__)
+
+#endif /* __MAC80211_DEBUG_H */