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, 115 insertions, 0 deletions

diff --git a/drivers/md/Makefile b/drivers/md/Makefile
new file mode 100644
index 000000000..517d1f7d8
--- /dev/null
+++ b/drivers/md/Makefile
@@ -0,0 +1,115 @@
+# SPDX-License-Identifier: GPL-2.0
+#
+# Makefile for the kernel software RAID and LVM drivers.
+#
+
+dm-mod-y	+= dm.o dm-table.o dm-target.o dm-linear.o dm-stripe.o \
+		   dm-ioctl.o dm-io.o dm-kcopyd.o dm-sysfs.o dm-stats.o \
+		   dm-rq.o dm-io-rewind.o
+dm-multipath-y	+= dm-path-selector.o dm-mpath.o
+dm-historical-service-time-y += dm-ps-historical-service-time.o
+dm-io-affinity-y += dm-ps-io-affinity.o
+dm-queue-length-y += dm-ps-queue-length.o
+dm-round-robin-y += dm-ps-round-robin.o
+dm-service-time-y += dm-ps-service-time.o
+dm-snapshot-y	+= dm-snap.o dm-exception-store.o dm-snap-transient.o \
+		    dm-snap-persistent.o
+dm-mirror-y	+= dm-raid1.o
+dm-log-userspace-y += dm-log-userspace-base.o dm-log-userspace-transfer.o
+dm-bio-prison-y += dm-bio-prison-v1.o dm-bio-prison-v2.o
+dm-thin-pool-y	+= dm-thin.o dm-thin-metadata.o
+dm-cache-y	+= dm-cache-target.o dm-cache-metadata.o dm-cache-policy.o \
+		    dm-cache-background-tracker.o
+dm-cache-smq-y	+= dm-cache-policy-smq.o
+dm-ebs-y	+= dm-ebs-target.o
+dm-era-y	+= dm-era-target.o
+dm-clone-y	+= dm-clone-target.o dm-clone-metadata.o
+dm-verity-y	+= dm-verity-target.o
+dm-zoned-y	+= dm-zoned-target.o dm-zoned-metadata.o dm-zoned-reclaim.o
+
+md-mod-y	+= md.o
+md-mod-$(CONFIG_MD_BITMAP)	+= md-bitmap.o
+md-mod-$(CONFIG_MD_LLBITMAP)	+= md-llbitmap.o
+raid456-y	+= raid5.o raid5-cache.o raid5-ppl.o
+linear-y       += md-linear.o
+
+# Note: link order is important.  All raid personalities
+# and must come before md.o, as they each initialise
+# themselves, and md.o may use the personalities when it
+# auto-initialised.
+
+obj-$(CONFIG_MD_LINEAR)		+= linear.o
+obj-$(CONFIG_MD_RAID0)		+= raid0.o
+obj-$(CONFIG_MD_RAID1)		+= raid1.o
+obj-$(CONFIG_MD_RAID10)		+= raid10.o
+obj-$(CONFIG_MD_RAID456)	+= raid456.o
+obj-$(CONFIG_MD_CLUSTER)	+= md-cluster.o
+obj-$(CONFIG_BCACHE)		+= bcache/
+obj-$(CONFIG_BLK_DEV_MD)	+= md-mod.o
+ifeq ($(CONFIG_BLK_DEV_MD),y)
+obj-y				+= md-autodetect.o
+endif
+obj-$(CONFIG_BLK_DEV_DM)	+= dm-mod.o
+obj-$(CONFIG_BLK_DEV_DM_BUILTIN) += dm-builtin.o
+obj-$(CONFIG_DM_UNSTRIPED)	+= dm-unstripe.o
+obj-$(CONFIG_DM_BUFIO)		+= dm-bufio.o
+obj-$(CONFIG_DM_BIO_PRISON)	+= dm-bio-prison.o
+obj-$(CONFIG_DM_CRYPT)		+= dm-crypt.o
+obj-$(CONFIG_DM_INLINECRYPT)	+= dm-inlinecrypt.o
+obj-$(CONFIG_DM_DELAY)		+= dm-delay.o
+obj-$(CONFIG_DM_DUST)		+= dm-dust.o
+obj-$(CONFIG_DM_FLAKEY)		+= dm-flakey.o
+obj-$(CONFIG_DM_MULTIPATH)	+= dm-multipath.o dm-round-robin.o
+obj-$(CONFIG_DM_MULTIPATH_QL)	+= dm-queue-length.o
+obj-$(CONFIG_DM_MULTIPATH_ST)	+= dm-service-time.o
+obj-$(CONFIG_DM_MULTIPATH_HST)	+= dm-historical-service-time.o
+obj-$(CONFIG_DM_MULTIPATH_IOA)	+= dm-io-affinity.o
+obj-$(CONFIG_DM_SWITCH)		+= dm-switch.o
+obj-$(CONFIG_DM_SNAPSHOT)	+= dm-snapshot.o
+obj-$(CONFIG_DM_PERSISTENT_DATA) += persistent-data/
+obj-$(CONFIG_DM_MIRROR)		+= dm-mirror.o dm-log.o dm-region-hash.o
+obj-$(CONFIG_DM_LOG_USERSPACE)	+= dm-log-userspace.o
+obj-$(CONFIG_DM_ZERO)		+= dm-zero.o
+obj-$(CONFIG_DM_RAID)		+= dm-raid.o
+obj-$(CONFIG_DM_THIN_PROVISIONING) += dm-thin-pool.o
+obj-$(CONFIG_DM_VERITY)		+= dm-verity.o
+obj-$(CONFIG_DM_VDO)            += dm-vdo/
+obj-$(CONFIG_DM_PCACHE)		+= dm-pcache/
+obj-$(CONFIG_DM_CACHE)		+= dm-cache.o
+obj-$(CONFIG_DM_CACHE_SMQ)	+= dm-cache-smq.o
+obj-$(CONFIG_DM_EBS)		+= dm-ebs.o
+obj-$(CONFIG_DM_ERA)		+= dm-era.o
+obj-$(CONFIG_DM_CLONE)		+= dm-clone.o
+obj-$(CONFIG_DM_LOG_WRITES)	+= dm-log-writes.o
+obj-$(CONFIG_DM_INTEGRITY)	+= dm-integrity.o
+obj-$(CONFIG_DM_ZONED)		+= dm-zoned.o
+obj-$(CONFIG_DM_WRITECACHE)	+= dm-writecache.o
+obj-$(CONFIG_SECURITY_LOADPIN_VERITY)	+= dm-verity-loadpin.o
+
+ifeq ($(CONFIG_DM_INIT),y)
+dm-mod-objs			+= dm-init.o
+endif
+
+ifeq ($(CONFIG_DM_UEVENT),y)
+dm-mod-objs			+= dm-uevent.o
+endif
+
+ifeq ($(CONFIG_BLK_DEV_ZONED),y)
+dm-mod-objs			+= dm-zone.o
+endif
+
+ifeq ($(CONFIG_IMA),y)
+dm-mod-objs			+= dm-ima.o
+endif
+
+ifeq ($(CONFIG_DM_VERITY_FEC),y)
+dm-verity-objs			+= dm-verity-fec.o
+endif
+
+ifeq ($(CONFIG_DM_VERITY_VERIFY_ROOTHASH_SIG),y)
+dm-verity-objs			+= dm-verity-verify-sig.o
+endif
+
+ifeq ($(CONFIG_DM_AUDIT),y)
+dm-mod-objs			+= dm-audit.o
+endif