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, 64 insertions, 0 deletions

diff --git a/drivers/usb/chipidea/Kconfig b/drivers/usb/chipidea/Kconfig
new file mode 100644
index 000000000..bab45bc62
--- /dev/null
+++ b/drivers/usb/chipidea/Kconfig
@@ -0,0 +1,64 @@
+# SPDX-License-Identifier: GPL-2.0
+
+config USB_CHIPIDEA
+	tristate "ChipIdea Highspeed Dual Role Controller"
+	depends on ((USB_EHCI_HCD && USB_GADGET) || (USB_EHCI_HCD && !USB_GADGET) || (!USB_EHCI_HCD && USB_GADGET)) && HAS_DMA
+	select EXTCON
+	select RESET_CONTROLLER
+	select USB_ULPI_BUS
+	select USB_ROLE_SWITCH
+	select USB_TEGRA_PHY if ARCH_TEGRA
+	help
+	  Say Y here if your system has a dual role high speed USB
+	  controller based on ChipIdea silicon IP. It supports:
+	  Dual-role switch (ID, OTG FSM, sysfs), Host-only, and
+	  Peripheral-only.
+
+	  When compiled dynamically, the module will be called ci_hdrc.ko.
+
+if USB_CHIPIDEA
+
+config USB_CHIPIDEA_UDC
+	bool "ChipIdea device controller"
+	depends on USB_GADGET
+	help
+	  Say Y here to enable device controller functionality of the
+	  ChipIdea driver.
+
+config USB_CHIPIDEA_HOST
+	bool "ChipIdea host controller"
+	depends on USB_EHCI_HCD
+	select USB_EHCI_ROOT_HUB_TT
+	help
+	  Say Y here to enable host controller functionality of the
+	  ChipIdea driver.
+
+config USB_CHIPIDEA_PCI
+	tristate "Enable PCI glue driver" if EXPERT
+	depends on USB_PCI
+	depends on NOP_USB_XCEIV
+	default USB_CHIPIDEA
+
+config USB_CHIPIDEA_MSM
+	tristate "Enable MSM hsusb glue driver" if EXPERT
+	default USB_CHIPIDEA
+
+config USB_CHIPIDEA_NPCM
+	tristate "Enable NPCM hsusb glue driver" if EXPERT
+	default USB_CHIPIDEA
+
+config USB_CHIPIDEA_IMX
+	tristate "Enable i.MX USB glue driver" if EXPERT
+	depends on OF
+	default USB_CHIPIDEA
+
+config USB_CHIPIDEA_GENERIC
+	tristate "Enable generic USB2 glue driver" if EXPERT
+	default USB_CHIPIDEA
+
+config USB_CHIPIDEA_TEGRA
+	tristate "Enable Tegra USB glue driver" if EXPERT
+	depends on OF
+	default USB_CHIPIDEA
+
+endif