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, 136 insertions, 0 deletions

diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile
new file mode 100644
index 000000000..d1b0affb8
--- /dev/null
+++ b/drivers/acpi/Makefile
@@ -0,0 +1,136 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the Linux ACPI interpreter
+#
+
+ccflags-$(CONFIG_ACPI_DEBUG)	+= -DACPI_DEBUG_OUTPUT
+
+ifdef CONFIG_TRACE_BRANCH_PROFILING
+CFLAGS_processor_idle.o += -DDISABLE_BRANCH_PROFILING
+endif
+
+#
+# ACPI Boot-Time Table Parsing
+#
+ifeq ($(CONFIG_ACPI_CUSTOM_DSDT),y)
+tables.o: $(src)/../../include/$(CONFIG_ACPI_CUSTOM_DSDT_FILE) ;
+
+endif
+
+obj-$(CONFIG_ACPI)		+= tables.o
+
+#
+# ACPI Core Subsystem (Interpreter)
+#
+obj-$(CONFIG_ACPI)		+= acpi.o \
+					acpica/
+
+# All the builtin files are in the "acpi." module_param namespace.
+acpi-y				+= osi.o osl.o utils.o reboot.o
+acpi-y				+= nvs.o
+
+# Power management related files
+acpi-y				+= wakeup.o
+acpi-$(CONFIG_ACPI_SYSTEM_POWER_STATES_SUPPORT) += sleep.o
+acpi-y				+= device_sysfs.o device_pm.o
+acpi-$(CONFIG_ACPI_SLEEP)	+= proc.o
+
+
+#
+# ACPI Bus and Device Drivers
+#
+acpi-y				+= bus.o glue.o
+acpi-y				+= scan.o mipi-disco-img.o
+acpi-y				+= resource.o
+acpi-y				+= acpi_processor.o
+acpi-y				+= processor_core.o
+acpi-$(CONFIG_ARCH_MIGHT_HAVE_ACPI_PDC) += processor_pdc.o
+acpi-$(CONFIG_ACPI_EC)		+= ec.o
+acpi-$(CONFIG_ACPI_DOCK)	+= dock.o
+acpi-$(CONFIG_PCI)		+= pci_root.o pci_link.o pci_irq.o
+obj-$(CONFIG_ACPI_MCFG)		+= pci_mcfg.o
+acpi-y				+= acpi_apd.o
+acpi-y				+= acpi_platform.o
+acpi-y				+= acpi_pnp.o
+acpi-y				+= power.o
+acpi-y				+= event.o
+acpi-y				+= evged.o
+acpi-y				+= sysfs.o
+acpi-y				+= property.o
+acpi-$(CONFIG_DEBUG_FS)		+= debugfs.o
+acpi-y				+= acpi_lpat.o
+acpi-$(CONFIG_ACPI_FPDT)	+= acpi_fpdt.o
+acpi-$(CONFIG_ACPI_LPIT)	+= acpi_lpit.o
+acpi-$(CONFIG_ACPI_GENERIC_GSI) += irq.o
+acpi-$(CONFIG_ACPI_WATCHDOG)	+= acpi_watchdog.o
+acpi-$(CONFIG_ACPI_PRMT)	+= prmt.o
+acpi-$(CONFIG_ACPI_PCC)		+= acpi_pcc.o
+acpi-$(CONFIG_ACPI_FFH)		+= acpi_ffh.o
+acpi-$(CONFIG_ACPI_MRRM)	+= acpi_mrrm.o
+
+# Address translation
+acpi-$(CONFIG_ACPI_ADXL)	+= acpi_adxl.o
+
+# These are (potentially) separate modules
+
+# IPMI may be used by other drivers, so it has to initialise before them
+obj-$(CONFIG_ACPI_IPMI)		+= acpi_ipmi.o
+
+obj-$(CONFIG_ACPI_AC) 		+= ac.o
+obj-$(CONFIG_ACPI_BUTTON)	+= button.o
+obj-$(CONFIG_ACPI_TINY_POWER_BUTTON)	+= tiny-power-button.o
+obj-$(CONFIG_ACPI_FAN)		+= fan.o
+fan-objs			:= fan_core.o
+fan-objs			+= fan_attr.o
+fan-$(CONFIG_HWMON)		+= fan_hwmon.o
+
+obj-$(CONFIG_ACPI_VIDEO)	+= video.o
+obj-$(CONFIG_ACPI_TAD)		+= acpi_tad.o
+obj-$(CONFIG_ACPI_PCI_SLOT)	+= pci_slot.o
+obj-$(CONFIG_ACPI_PROCESSOR)	+= processor.o
+obj-$(CONFIG_ACPI)		+= container.o
+obj-$(CONFIG_ACPI_THERMAL_LIB)	+= thermal_lib.o
+obj-$(CONFIG_ACPI_THERMAL)	+= thermal.o
+obj-$(CONFIG_ACPI_PLATFORM_PROFILE) 	+= platform_profile.o
+obj-$(CONFIG_ACPI_NFIT)		+= nfit/
+obj-$(CONFIG_ACPI_NHLT)		+= nhlt.o
+obj-$(CONFIG_ACPI_NUMA)		+= numa/
+obj-$(CONFIG_ACPI)		+= acpi_memhotplug.o
+obj-$(CONFIG_ACPI_HOTPLUG_IOAPIC) += ioapic.o
+obj-$(CONFIG_ACPI_BATTERY)	+= battery.o
+obj-$(CONFIG_ACPI_SBS)		+= sbshc.o
+obj-$(CONFIG_ACPI_SBS)		+= sbs.o
+obj-$(CONFIG_ACPI_HED)		+= hed.o
+obj-$(CONFIG_ACPI_EC_DEBUGFS)	+= ec_sys.o
+obj-$(CONFIG_ACPI_BGRT)		+= bgrt.o
+obj-$(CONFIG_ACPI_CPPC_LIB)	+= cppc_acpi.o
+obj-$(CONFIG_ACPI_SPCR_TABLE)	+= spcr.o
+obj-$(CONFIG_ACPI_DEBUGGER_USER) += acpi_dbg.o
+obj-$(CONFIG_ACPI_PPTT) 	+= pptt.o
+obj-$(CONFIG_ACPI_PFRUT)	+= pfr_update.o pfr_telemetry.o
+
+# processor has its own "processor." module_param namespace
+processor-y			:= processor_driver.o processor_thermal.o
+processor-$(CONFIG_ACPI_PROCESSOR_IDLE) += processor_idle.o
+processor-$(CONFIG_ACPI_CPU_FREQ_PSS)	+= processor_throttling.o
+processor-$(CONFIG_CPU_FREQ)	+= processor_perflib.o
+
+obj-$(CONFIG_ACPI_PROCESSOR_AGGREGATOR) += acpi_pad.o
+
+obj-$(CONFIG_ACPI_APEI)		+= apei/
+
+obj-$(CONFIG_ACPI_EXTLOG)	+= acpi_extlog.o
+
+obj-$(CONFIG_ACPI_CONFIGFS)	+= acpi_configfs.o
+
+obj-y				+= pmic/
+
+video-objs			+= acpi_video.o video_detect.o
+obj-y				+= dptf/
+
+obj-$(CONFIG_ARM64)		+= arm64/
+
+obj-$(CONFIG_ACPI_VIOT)		+= viot.o
+
+obj-$(CONFIG_RISCV)		+= riscv/
+obj-$(CONFIG_X86)		+= x86/