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, 41 insertions, 0 deletions

diff --git a/drivers/phy/spacemit/Kconfig b/drivers/phy/spacemit/Kconfig
new file mode 100644
index 000000000..5fdf18fce
--- /dev/null
+++ b/drivers/phy/spacemit/Kconfig
@@ -0,0 +1,41 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Phy drivers for SpacemiT platforms
+#
+config PHY_SPACEMIT_K1_PCIE
+	tristate "PCIe and combo PHY driver for the SpacemiT K1 SoC"
+	depends on ARCH_SPACEMIT || COMPILE_TEST
+	depends on COMMON_CLK
+	depends on HAS_IOMEM
+	depends on OF
+	select GENERIC_PHY
+	default ARCH_SPACEMIT
+	help
+	  Enable support for the PCIe and USB 3 combo PHY and two
+	  PCIe-only PHYs used in the SpacemiT K1 SoC.
+
+config PHY_SPACEMIT_K1_USB2
+	tristate "SpacemiT K1 USB 2.0 PHY support"
+	depends on (ARCH_SPACEMIT || COMPILE_TEST) && OF
+	depends on COMMON_CLK
+	depends on USB_COMMON
+	select GENERIC_PHY
+	help
+	  Enable this to support K1 USB 2.0 PHY driver. This driver takes care of
+	  enabling and clock setup and will be used by K1 udc/ehci/otg/xhci driver.
+
+config PHY_SPACEMIT_K3_COMMON_OPS
+	tristate
+	select MFD_SYSCON
+	select GENERIC_PHY
+
+config PHY_SPACEMIT_K3_COMBO_PHY
+	tristate "SpacemiT K3 USB3/PCIe PHY support"
+	depends on (ARCH_SPACEMIT || COMPILE_TEST) && OF
+	depends on COMMON_CLK
+	select PHY_SPACEMIT_K3_COMMON_OPS
+	help
+	  Enable this to support K3 USB3/PCIe combo PHY driver. This
+	  driver takes care of enabling and clock setup and will be used
+	  by K3 dwc3 driver.
+	  If unsure, say N.