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, 214 insertions, 0 deletions

diff --git a/tools/docs/get_abi.py b/tools/docs/get_abi.py
new file mode 100755
index 000000000..2f0b99401
--- /dev/null
+++ b/tools/docs/get_abi.py
@@ -0,0 +1,214 @@
+#!/usr/bin/env python3
+# pylint: disable=R0903
+# Copyright(c) 2025: Mauro Carvalho Chehab <mchehab@kernel.org>.
+# SPDX-License-Identifier: GPL-2.0
+
+"""
+Parse ABI documentation and produce results from it.
+"""
+
+import argparse
+import logging
+import os
+import sys
+
+# Import Python modules
+
+LIB_DIR = "../lib/python"
+SRC_DIR = os.path.dirname(os.path.realpath(__file__))
+
+sys.path.insert(0, os.path.join(SRC_DIR, LIB_DIR))
+
+from abi.abi_parser import AbiParser                # pylint: disable=C0413
+from abi.abi_regex import AbiRegex                  # pylint: disable=C0413
+from abi.helpers import ABI_DIR, DEBUG_HELP         # pylint: disable=C0413
+from abi.system_symbols import SystemSymbols        # pylint: disable=C0413
+
+# Command line classes
+
+
+REST_DESC = """
+Produce output in ReST format.
+
+The output is done on two sections:
+
+- Symbols: show all parsed symbols in alphabetic order;
+- Files: cross reference the content of each file with the symbols on it.
+"""
+
+class AbiRest:
+    """Initialize an argparse subparser for rest output"""
+
+    def __init__(self, subparsers):
+        """Initialize argparse subparsers"""
+
+        parser = subparsers.add_parser("rest",
+                                       formatter_class=argparse.RawTextHelpFormatter,
+                                       description=REST_DESC)
+
+        parser.add_argument("--enable-lineno",  action="store_true",
+                            help="enable lineno")
+        parser.add_argument("--raw", action="store_true",
+                            help="output text as contained in the ABI files. "
+                                 "It not used, output will contain dynamically"
+                                 " generated cross references when possible.")
+        parser.add_argument("--no-file", action="store_true",
+                            help="Don't the files section")
+        parser.add_argument("--show-hints", help="Show-hints")
+
+        parser.set_defaults(func=self.run)
+
+    def run(self, args):
+        """Run subparser"""
+
+        parser = AbiParser(args.dir, debug=args.debug)
+        parser.parse_abi()
+        parser.check_issues()
+
+        for t in parser.doc(args.raw, not args.no_file):
+            if args.enable_lineno:
+                print (f".. LINENO {t[1]}#{t[2]}\n\n")
+
+            print(t[0])
+
+class AbiValidate:
+    """Initialize an argparse subparser for ABI validation"""
+
+    def __init__(self, subparsers):
+        """Initialize argparse subparsers"""
+
+        parser = subparsers.add_parser("validate",
+                                       formatter_class=argparse.ArgumentDefaultsHelpFormatter,
+                                       description="list events")
+
+        parser.set_defaults(func=self.run)
+
+    def run(self, args):
+        """Run subparser"""
+
+        parser = AbiParser(args.dir, debug=args.debug)
+        parser.parse_abi()
+        parser.check_issues()
+
+
+class AbiSearch:
+    """Initialize an argparse subparser for ABI search"""
+
+    def __init__(self, subparsers):
+        """Initialize argparse subparsers"""
+
+        parser = subparsers.add_parser("search",
+                                       formatter_class=argparse.ArgumentDefaultsHelpFormatter,
+                                       description="Search ABI using a regular expression")
+
+        parser.add_argument("expression",
+                            help="Case-insensitive search pattern for the ABI symbol")
+
+        parser.set_defaults(func=self.run)
+
+    def run(self, args):
+        """Run subparser"""
+
+        parser = AbiParser(args.dir, debug=args.debug)
+        parser.parse_abi()
+        parser.search_symbols(args.expression)
+
+UNDEFINED_DESC="""
+Check undefined ABIs on local machine.
+
+Read sysfs devnodes and check if the devnodes there are defined inside
+ABI documentation.
+
+The search logic tries to minimize the number of regular expressions to
+search per each symbol.
+
+By default, it runs on a single CPU, as Python support for CPU threads
+is still experimental, and multi-process runs on Python is very slow.
+
+On experimental tests, if the number of ABI symbols to search per devnode
+is contained on a limit of ~150 regular expressions, using a single CPU
+is a lot faster than using multiple processes. However, if the number of
+regular expressions to check is at the order of ~30000, using multiple
+CPUs speeds up the check.
+"""
+
+class AbiUndefined:
+    """
+    Initialize an argparse subparser for logic to check undefined ABI at
+    the current machine's sysfs
+    """
+
+    def __init__(self, subparsers):
+        """Initialize argparse subparsers"""
+
+        parser = subparsers.add_parser("undefined",
+                                       formatter_class=argparse.RawTextHelpFormatter,
+                                       description=UNDEFINED_DESC)
+
+        parser.add_argument("-S", "--sysfs-dir", default="/sys",
+                            help="directory where sysfs is mounted")
+        parser.add_argument("-s", "--search-string",
+                            help="search string regular expression to limit symbol search")
+        parser.add_argument("-H", "--show-hints", action="store_true",
+                            help="Hints about definitions for missing ABI symbols.")
+        parser.add_argument("-j", "--jobs", "--max-workers", type=int, default=1,
+                            help="If bigger than one, enables multiprocessing.")
+        parser.add_argument("-c", "--max-chunk-size", type=int, default=50,
+                            help="Maximum number of chunk size")
+        parser.add_argument("-f", "--found", action="store_true",
+                            help="Also show found items. "
+                                 "Helpful to debug the parser."),
+        parser.add_argument("-d", "--dry-run", action="store_true",
+                            help="Don't actually search for undefined. "
+                                 "Helpful to debug the parser."),
+
+        parser.set_defaults(func=self.run)
+
+    def run(self, args):
+        """Run subparser"""
+
+        abi = AbiRegex(args.dir, debug=args.debug,
+                       search_string=args.search_string)
+
+        abi_symbols = SystemSymbols(abi=abi, hints=args.show_hints,
+                                    sysfs=args.sysfs_dir)
+
+        abi_symbols.check_undefined_symbols(dry_run=args.dry_run,
+                                            found=args.found,
+                                            max_workers=args.jobs,
+                                            chunk_size=args.max_chunk_size)
+
+
+def main():
+    """Main program"""
+
+    parser = argparse.ArgumentParser(formatter_class=argparse.RawTextHelpFormatter)
+
+    parser.add_argument("-d", "--debug", type=int, default=0, help="debug level")
+    parser.add_argument("-D", "--dir", default=ABI_DIR, help=DEBUG_HELP)
+
+    subparsers = parser.add_subparsers()
+
+    AbiRest(subparsers)
+    AbiValidate(subparsers)
+    AbiSearch(subparsers)
+    AbiUndefined(subparsers)
+
+    args = parser.parse_args()
+
+    if args.debug:
+        level = logging.DEBUG
+    else:
+        level = logging.INFO
+
+    logging.basicConfig(level=level, format="[%(levelname)s] %(message)s")
+
+    if "func" in args:
+        args.func(args)
+    else:
+        sys.exit(f"Please specify a valid command for {sys.argv[0]}")
+
+
+# Call main method
+if __name__ == "__main__":
+    main()