KVM: Don't pre-reserve xarray entries when storing empty/NULL attributesgrafted

Skip the xarray reservation loop when clearing all memory attributes, as
storing NULL only erases the entry and never needs to allocate, so no
reservation (and no cleanup of a failed one) is required in that case.

Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: David Ballesteros <davimaba.v@proton.me>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com
[sean: split to separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.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/