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, 38 insertions, 0 deletions

diff --git a/drivers/net/pcs/Kconfig b/drivers/net/pcs/Kconfig
new file mode 100644
index 000000000..e417fd66f
--- /dev/null
+++ b/drivers/net/pcs/Kconfig
@@ -0,0 +1,38 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# PCS Layer Configuration
+#
+
+menu "PCS device drivers"
+
+config PCS_XPCS
+	tristate "Synopsys DesignWare Ethernet XPCS"
+	select PHYLINK
+	help
+	  This module provides a driver and helper functions for Synopsys
+	  DesignWare XPCS controllers.
+
+config PCS_LYNX
+	tristate
+	help
+	  This module provides helpers to phylink for managing the Lynx PCS
+	  which is part of the Layerscape and QorIQ Ethernet SERDES.
+
+config PCS_MTK_LYNXI
+	tristate
+	select PHY_COMMON_PROPS
+	select REGMAP
+	help
+	  This module provides helpers to phylink for managing the LynxI PCS
+	  which is part of MediaTek's SoC and Ethernet switch ICs.
+
+config PCS_RZN1_MIIC
+	tristate "Renesas RZ/N1, RZ/N2H, RZ/T2H MII converter"
+	depends on OF
+	depends on ARCH_RENESAS || COMPILE_TEST
+	help
+	  This module provides a driver for the MII converter available on
+	  Renesas RZ/N1, RZ/N2H, and RZ/T2H SoCs. This PCS converts MII to
+	  RMII/RGMII, or can be set in pass-through mode for MII.
+
+endmenu