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, 194 insertions, 0 deletions

diff --git a/scripts/parse-maintainers.pl b/scripts/parse-maintainers.pl
new file mode 100755
index 000000000..2ca4eb3f1
--- /dev/null
+++ b/scripts/parse-maintainers.pl
@@ -0,0 +1,194 @@
+#!/usr/bin/perl -w
+# SPDX-License-Identifier: GPL-2.0
+
+use strict;
+use Getopt::Long qw(:config no_auto_abbrev);
+
+my $input_file = "MAINTAINERS";
+my $output_file = "MAINTAINERS.new";
+my $output_section = "SECTION.new";
+my $help = 0;
+my $order = 0;
+my $P = $0;
+
+if (!GetOptions(
+		'input=s' => \$input_file,
+		'output=s' => \$output_file,
+		'section=s' => \$output_section,
+		'order!' => \$order,
+		'h|help|usage' => \$help,
+	    )) {
+    die "$P: invalid argument - use --help if necessary\n";
+}
+
+if ($help != 0) {
+    usage();
+    exit 0;
+}
+
+sub usage {
+    print <<EOT;
+usage: $P [options] <pattern matching regexes>
+
+  --input => MAINTAINERS file to read (default: MAINTAINERS)
+  --output => sorted MAINTAINERS file to write (default: MAINTAINERS.new)
+  --section => new sorted MAINTAINERS file to write to (default: SECTION.new)
+  --order => Use the preferred section content output ordering (default: 0)
+    Preferred ordering of section output is:
+      M:  Person acting as a maintainer
+      R:  Person acting as a patch reviewer
+      L:  Mailing list where patches should be sent
+      S:  Maintenance status
+      W:  URI for general information
+      Q:  URI for patchwork tracking
+      B:  URI for bug tracking/submission
+      C:  URI for chat
+      P:  URI or file for subsystem specific coding styles
+      T:  SCM tree type and location
+      F:  File and directory pattern
+      X:  File and directory exclusion pattern
+      N:  File glob
+      K:  Keyword - patch content regex
+
+If <pattern match regexes> exist, then the sections that match the
+regexes are not written to the output file but are written to the
+section file.
+
+EOT
+}
+
+# sort comparison functions
+sub by_category($$) {
+    my ($a, $b) = @_;
+
+    $a = uc $a;
+    $b = uc $b;
+
+    # This always sorts last
+    $a =~ s/THE REST/ZZZZZZ/g;
+    $b =~ s/THE REST/ZZZZZZ/g;
+
+    return $a cmp $b;
+}
+
+sub by_pattern($$) {
+    my ($a, $b) = @_;
+    my $preferred_order = 'MRLSWQBCPTFXNK';
+
+    my $a1 = uc(substr($a, 0, 1));
+    my $b1 = uc(substr($b, 0, 1));
+
+    my $a_index = index($preferred_order, $a1);
+    my $b_index = index($preferred_order, $b1);
+
+    $a_index = 1000 if ($a_index == -1);
+    $b_index = 1000 if ($b_index == -1);
+
+    if (($a1 =~ /^F$/ && $b1 =~ /^F$/) ||
+	($a1 =~ /^X$/ && $b1 =~ /^X$/)) {
+	return $a cmp $b;
+    }
+
+    if ($a_index < $b_index) {
+	return -1;
+    } elsif ($a_index == $b_index) {
+	return 0;
+    } else {
+	return 1;
+    }
+}
+
+sub trim {
+    my $s = shift;
+    $s =~ s/\s+$//;
+    $s =~ s/^\s+//;
+    return $s;
+}
+
+sub alpha_output {
+    my ($hashref, $filename) = (@_);
+
+    return if ! scalar(keys %$hashref);
+
+    open(my $file, '>', "$filename") or die "$P: $filename: open failed - $!\n";
+    my $separator;
+    foreach my $key (sort by_category keys %$hashref) {
+	if ($key eq " ") {
+	    print $file $$hashref{$key};
+	} else {
+	    if (! defined $separator) {
+		$separator = "\n";
+	    } else {
+		print $file $separator;
+	    }
+	    print $file $key . "\n";
+	    if ($order) {
+		foreach my $pattern (sort by_pattern split('\n', %$hashref{$key})) {
+		    print $file ($pattern . "\n");
+		}
+	    } else {
+		foreach my $pattern (split('\n', %$hashref{$key})) {
+		    print $file ($pattern . "\n");
+		}
+	    }
+	}
+    }
+    close($file);
+}
+
+sub file_input {
+    my ($hashref, $filename) = (@_);
+
+    my $lastline = "";
+    my $case = " ";
+    $$hashref{$case} = "";
+
+    open(my $file, '<', "$filename") or die "$P: $filename: open failed - $!\n";
+
+    while (<$file>) {
+        my $line = $_;
+
+        # Pattern line?
+        if ($line =~ m/^([A-Z]):\s*(.*)/) {
+            $line = $1 . ":\t" . trim($2) . "\n";
+            if ($lastline eq "") {
+                $$hashref{$case} = $$hashref{$case} . $line;
+                next;
+            }
+            $case = trim($lastline);
+            exists $$hashref{$case} and die "Header '$case' already exists";
+            $$hashref{$case} = $line;
+            $lastline = "";
+            next;
+        }
+
+        if ($case eq " ") {
+            $$hashref{$case} = $$hashref{$case} . $lastline;
+            $lastline = $line;
+            next;
+        }
+        trim($lastline) eq "" or die ("Odd non-pattern line '$lastline' for '$case'");
+        $lastline = $line;
+    }
+    $$hashref{$case} = $$hashref{$case} . $lastline;
+    close($file);
+}
+
+my %hash;
+my %new_hash;
+
+file_input(\%hash, $input_file);
+
+foreach my $type (@ARGV) {
+    foreach my $key (keys %hash) {
+	if ($key =~ /$type/ || $hash{$key} =~ /$type/) {
+	    $new_hash{$key} = $hash{$key};
+	    delete $hash{$key};
+	}
+    }
+}
+
+alpha_output(\%hash, $output_file);
+alpha_output(\%new_hash, $output_section);
+
+exit(0);