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, 59 insertions, 0 deletions

diff --git a/drivers/phy/allwinner/Kconfig b/drivers/phy/allwinner/Kconfig
new file mode 100644
index 000000000..fb584518b
--- /dev/null
+++ b/drivers/phy/allwinner/Kconfig
@@ -0,0 +1,59 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Phy drivers for Allwinner platforms
+#
+config PHY_SUN4I_USB
+	tristate "Allwinner sunxi SoC USB PHY driver"
+	depends on ARCH_SUNXI || COMPILE_TEST
+	depends on HAS_IOMEM
+	depends on RESET_CONTROLLER
+	depends on EXTCON
+	depends on POWER_SUPPLY
+	depends on USB_SUPPORT
+	select GENERIC_PHY
+	select USB_COMMON
+	help
+	  Enable this to support the transceiver that is part of Allwinner
+	  sunxi SoCs.
+
+	  This driver controls the entire USB PHY block, both the USB OTG
+	  parts, as well as the 2 regular USB 2 host PHYs.
+
+config PHY_SUN6I_MIPI_DPHY
+	tristate "Allwinner A31 MIPI D-PHY Support"
+	depends on ARCH_SUNXI || COMPILE_TEST
+	depends on HAS_IOMEM && COMMON_CLK
+	depends on RESET_CONTROLLER
+	select GENERIC_PHY
+	select GENERIC_PHY_MIPI_DPHY
+	select REGMAP_MMIO
+	help
+	  Choose this option if you have an Allwinner SoC with
+	  MIPI-DSI support. If M is selected, the module will be
+	  called sun6i_mipi_dphy.
+
+config PHY_SUN9I_USB
+	tristate "Allwinner sun9i SoC USB PHY driver"
+	depends on ARCH_SUNXI || COMPILE_TEST
+	depends on HAS_IOMEM
+	depends on RESET_CONTROLLER
+	depends on USB_SUPPORT
+	select USB_COMMON
+	select GENERIC_PHY
+	help
+	  Enable this to support the transceiver that is part of Allwinner
+	  sun9i SoCs.
+
+	  This driver controls each individual USB 2 host PHY.
+
+config PHY_SUN50I_USB3
+	tristate "Allwinner H6 SoC USB3 PHY driver"
+	depends on ARCH_SUNXI || COMPILE_TEST
+	depends on HAS_IOMEM && OF
+	depends on RESET_CONTROLLER
+	select GENERIC_PHY
+	help
+	  Enable this to support the USB3.0-capable transceiver that is
+	  part of Allwinner H6 SoC.
+
+	  This driver controls each individual USB 2+3 host PHY combo.