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/drivers/phy/socionext/Kconfig b/drivers/phy/socionext/Kconfig
new file mode 100644
index 000000000..8ae644756
--- /dev/null
+++ b/drivers/phy/socionext/Kconfig
@@ -0,0 +1,46 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# PHY drivers for Socionext platforms.
+#
+
+config PHY_UNIPHIER_USB2
+	tristate "UniPhier USB2 PHY driver"
+	depends on ARCH_UNIPHIER || COMPILE_TEST
+	depends on OF && HAS_IOMEM
+	select GENERIC_PHY
+	select MFD_SYSCON
+	help
+	  Enable this to support USB PHY implemented on USB2 controller
+	  on UniPhier SoCs. This driver provides interface to interact
+	  with USB 2.0 PHY that is part of the UniPhier SoC.
+	  In case of Pro4, it is necessary to specify this USB2 PHY instead
+	  of USB3 HS-PHY.
+
+config PHY_UNIPHIER_USB3
+	tristate "UniPhier USB3 PHY driver"
+	depends on ARCH_UNIPHIER || COMPILE_TEST
+	depends on OF && HAS_IOMEM
+	select GENERIC_PHY
+	help
+	  Enable this to support USB PHY implemented in USB3 controller
+	  on UniPhier SoCs. This controller supports USB3.0 and lower speed.
+
+config PHY_UNIPHIER_PCIE
+	tristate "Uniphier PHY driver for PCIe controller"
+	depends on ARCH_UNIPHIER || COMPILE_TEST
+	depends on OF && HAS_IOMEM
+	default PCIE_UNIPHIER
+	select GENERIC_PHY
+	help
+	  Enable this to support PHY implemented in PCIe controller
+	  on UniPhier SoCs. This driver supports LD20 and PXs3 SoCs.
+
+config PHY_UNIPHIER_AHCI
+	tristate "UniPhier AHCI PHY driver"
+	depends on ARCH_UNIPHIER || COMPILE_TEST
+	depends on OF && HAS_IOMEM
+	default SATA_AHCI_PLATFORM
+	select GENERIC_PHY
+	help
+	  Enable this to support PHY implemented in AHCI controller
+	  on UniPhier SoCs. This driver supports Pro4, PXs2 and PXs3 SoCs.