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, 37 insertions, 0 deletions

diff --git a/arch/powerpc/boot/install.sh b/arch/powerpc/boot/install.sh
new file mode 100755
index 000000000..c3df6c27c
--- /dev/null
+++ b/arch/powerpc/boot/install.sh
@@ -0,0 +1,37 @@
+#!/bin/sh
+#
+# This file is subject to the terms and conditions of the GNU General Public
+# License.  See the file "COPYING" in the main directory of this archive
+# for more details.
+#
+# Copyright (C) 1995 by Linus Torvalds
+#
+# Blatantly stolen from in arch/i386/boot/install.sh by Dave Hansen 
+#
+# "make install" script for ppc64 architecture
+#
+# Arguments:
+#   $1 - kernel version
+#   $2 - kernel image file
+#   $3 - kernel map file
+#   $4 - default install path (blank if root directory)
+
+set -e
+
+# this should work for both the pSeries zImage and the iSeries vmlinux.sm
+image_name=$(basename "$2")
+
+
+echo "Warning: '${INSTALLKERNEL}' command not available... Copying" \
+     "directly to $4/$image_name-$1" >&2
+
+if [ -f "$4"/"$image_name"-"$1" ]; then
+	mv "$4"/"$image_name"-"$1" "$4"/"$image_name"-"$1".old
+fi
+
+if [ -f "$4"/System.map-"$1" ]; then
+	mv "$4"/System.map-"$1" "$4"/System-"$1".old
+fi
+
+cat "$2" > "$4"/"$image_name"-"$1"
+cp "$3" "$4"/System.map-"$1"