[PATCH 2/2] t/io_uring_pi: test script for io_uring PI

Vincent Fu
2025-07-23T17:05:54Z

Test io_uring metadata support on NVMe devices.
Limited to direct=1 and metadata in a separate buffer.

Signed-off-by: Vincent Fu <vincent.fu@samsung.com>
---
t/io_uring_pi.py | 408 +++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 408 insertions(+)
create mode 100644 t/io_uring_pi.py

diff --git a/t/io_uring_pi.py b/t/io_uring_pi.py
new file mode 100644
index 00000000..bd92edfd
--- /dev/null
+++ b/t/io_uring_pi.py
@@ -0,0 +1,408 @@
+#!/usr/bin/env python3
+
+"""
+# io_uring_pi.py
+#
+# Test metadata support using the io_uring ioengine.
+#
+# USAGE
+# See python3 io_uring_pi.py --help
+#
+# EXAMPLES (THIS IS A DESTRUCTIVE TEST!!)
+# python3 t/io_uring_pi.py --dut /dev/nvme1n1 -f ./fio
+#
+# REQUIREMENTS
+# Python 3.6
+#
+"""
+
+import os
+import sys
+import json
+import time
+import locale
+import logging
+import argparse
+import itertools
+import subprocess
+from pathlib import Path
+from fiotestlib import FioJobCmdTest, run_fio_tests
+from fiotestcommon import SUCCESS_NONZERO
+
+
+NUMBER_IOS = 8192
+BS_LOW = 1
+BS_HIGH = 16
+
+class DifDixTest(FioJobCmdTest):
+ """
+ NVMe DIF/DIX test class.
+ """
+
+ def setup(self, parameters):
+ """Setup a test."""
+
+ fio_args = [
+ "--name=io_uring_pi",
+ "--ioengine=io_uring",
+ "--direct=1",
+ f"--filename={self.fio_opts['filename']}",
+ f"--rw={self.fio_opts['rw']}",
+ f"--bsrange={self.fio_opts['bsrange']}",
+ f"--output={os.path.basename(self.filenames['output'])}",
+ f"--md_per_io_size={self.fio_opts['md_per_io_size']}",
+ "--pi_act=0",
+ f"--pi_chk={self.fio_opts['pi_chk']}",
+ f"--apptag={self.fio_opts['apptag']}",
+ f"--apptag_mask={self.fio_opts['apptag_mask']}",
+ ]
+ for opt in ['fixedbufs', 'nonvectored', 'force_async', 'registerfiles',
+ 'sqthread_poll', 'sqthread_poll_cpu', 'hipri', 'nowait',
+ 'time_based', 'runtime', 'verify', 'io_size', 'offset', 'number_ios',
+ 'output-format']:
+ if opt in self.fio_opts:
+ option = f"--{opt}={self.fio_opts[opt]}"
+ fio_args.append(option)
+
+ super().setup(fio_args)
+
+
+TEST_LIST = [
+#
+# Write data with pi_act=0 and then read the data back
+#
+ {
+ # Write workload with variable IO sizes
+ # pi_act=0
+ "test_id": 101,
+ "fio_opts": {
+ "rw": 'write',
+ "number_ios": NUMBER_IOS,
+ "output-format": "json",
+ "apptag": "0x8888",
+ "apptag_mask": "0xFFFF",
+ "pi_act": 0,
+ },
+ "pi_chk": "GUARD,REFTAG,APPTAG",
+ "bs_low": BS_LOW,
+ "bs_high": BS_HIGH,
+ "test_class": DifDixTest,
+ },
+ {
+ # Read workload with fixed small IO size
+ # pi_act=0
+ "test_id": 102,
+ "fio_opts": {
+ "rw": 'read',
+ "number_ios": NUMBER_IOS,
+ "output-format": "json",
+ "apptag": "0x8888",
+ "apptag_mask": "0xFFFF",
+ "pi_act": 0,
+ },
+ "pi_chk": "GUARD,REFTAG,APPTAG",
+ "bs_low": BS_LOW,
+ "bs_high": BS_LOW,
+ "test_class": DifDixTest,
+ },
+ {
+ # Read workload with variable IO size
+ # pi_act=0
+ "test_id": 103,
+ "fio_opts": {
+ "rw": 'read',
+ "number_ios": NUMBER_IOS,
+ "output-format": "json",
+ "apptag": "0x8888",
+ "apptag_mask": "0xFFFF",
+ "pi_act": 0,
+ },
+ "pi_chk": "GUARD,REFTAG,APPTAG",
+ "bs_low": BS_LOW,
+ "bs_high": BS_HIGH,
+ "test_class": DifDixTest,
+ },
+ {
+ # Read workload with variable IO size
+ # trigger apptag mismatch error
+ # pi_act=0
+ "test_id": 104,
+ "fio_opts": {
+ "rw": 'read',
+ "number_ios": NUMBER_IOS,
+ "output-format": "json",
+ "apptag": "0xA888",
+ "apptag_mask": "0xFFFF",
+ "pi_act": 0,
+ },
+ "pi_chk": "GUARD,REFTAG,APPTAG",
+ "bs_low": BS_LOW,
+ "bs_high": BS_HIGH,
+ "success": SUCCESS_NONZERO,
+ "test_class": DifDixTest,
+ },
+ {
+ # Read workload with variable IO size
+ # fails because apptag mask must be 0xFFFF
+ # pi_act=0
+ "test_id": 105,
+ "fio_opts": {
+ "rw": 'read',
+ "number_ios": NUMBER_IOS,
+ "output-format": "json",
+ "apptag": "0xF888",
+ "apptag_mask": "0x0FFF",
+ "pi_act": 0,
+ },
+ "pi_chk": "GUARD,REFTAG,APPTAG",
+ "bs_low": BS_LOW,
+ "bs_high": BS_HIGH,
+ "success": SUCCESS_NONZERO,
+ "test_class": DifDixTest,
+ },
+]
+
+
+def get_lbafs(args):
+ """
+ Determine which LBA formats to use. Use either the ones specified on the
+ command line or if none are specified query the device and use all lba
+ formats with metadata.
+ """
+ lbaf_list = []
+ id_ns_cmd = f"sudo nvme id-ns --output-format=json {args.dut}".split(' ')
+ id_ns_output = subprocess.check_output(id_ns_cmd)
+ lbafs = json.loads(id_ns_output)['lbafs']
+ if args.lbaf:
+ for lbaf in args.lbaf:
+ lbaf_list.append({'lbaf': lbaf, 'ds': 2 ** lbafs[lbaf]['ds'],
+ 'ms': lbafs[lbaf]['ms'], })
+ if lbafs[lbaf]['ms'] == 0:
+ print(f'Error: lbaf {lbaf} has metadata size zero')
+ sys.exit(1)
+ else:
+ for lbaf_num, lbaf in enumerate(lbafs):
+ if lbaf['ms'] != 0:
+ lbaf_list.append({'lbaf': lbaf_num, 'ds': 2 ** lbaf['ds'],
+ 'ms': lbaf['ms'], })
+
+ return lbaf_list
+
+
+def get_guard_pi(lbaf_list, args):
+ """
+ Find out how many bits of guard protection information are associated with
+ each lbaf to be used. If this is not available assume 16-bit guard pi.
+ Also record the bytes of protection information associated with the number
+ of guard PI bits.
+ """
+ nvm_id_ns_cmd = f"sudo nvme nvm-id-ns --output-format=json {args.dut}".split(' ')
+ try:
+ nvm_id_ns_output = subprocess.check_output(nvm_id_ns_cmd)
+ except subprocess.CalledProcessError:
+ print(f"Non-zero return code from {' '.join(nvm_id_ns_cmd)}; " \
+ "assuming all lbafs use 16b Guard Protection Information")
+ for lbaf in lbaf_list:
+ lbaf['guard_pi_bits'] = 16
+ else:
+ elbafs = json.loads(nvm_id_ns_output)['elbafs']
+ for elbaf_num, elbaf in enumerate(elbafs):
+ for lbaf in lbaf_list:
+ if lbaf['lbaf'] == elbaf_num:
+ lbaf['guard_pi_bits'] = 16 << elbaf['pif']
+
+ # For 16b Guard Protection Information, the PI requires 8 bytes
+ # For 32b and 64b Guard PI, the PI requires 16 bytes
+ for lbaf in lbaf_list:
+ if lbaf['guard_pi_bits'] == 16:
+ lbaf['pi_bytes'] = 8
+ else:
+ lbaf['pi_bytes'] = 16
+
+
+def get_capabilities(args):
+ """
+ Determine what end-to-end data protection features the device supports.
+ """
+ caps = { 'pil': [], 'pitype': [], 'elba': [] }
+ id_ns_cmd = f"sudo nvme id-ns --output-format=json {args.dut}".split(' ')
+ id_ns_output = subprocess.check_output(id_ns_cmd)
+ id_ns_json = json.loads(id_ns_output)
+
+ mc = id_ns_json['mc']
+ if mc & 1:
+ caps['elba'].append(1)
+ if mc & 2:
+ caps['elba'].append(0)
+
+ dpc = id_ns_json['dpc']
+ if dpc & 1:
+ caps['pitype'].append(1)
+ if dpc & 2:
+ caps['pitype'].append(2)
+ if dpc & 4:
+ caps['pitype'].append(3)
+ if dpc & 8:
+ caps['pil'].append(1)
+ if dpc & 16:
+ caps['pil'].append(0)
+
+ for _, value in caps.items():
+ if len(value) == 0:
+ logging.error("One or more end-to-end data protection features unsupported: %s", caps)
+ sys.exit(-1)
+
+ return caps
+
+
+def format_device(args, lbaf, pitype, pil, elba):
+ """
+ Format device using specified lba format with specified pitype, pil, and
+ elba values.
+ """
+
+ format_cmd = f"sudo nvme format {args.dut} --lbaf={lbaf['lbaf']} " \
+ f"--pi={pitype} --pil={pil} --ms={elba} --force"
+ logging.debug("Format command: %s", format_cmd)
+ format_cmd = format_cmd.split(' ')
+ format_cmd_result = subprocess.run(format_cmd, capture_output=True, check=False,
+ encoding=locale.getpreferredencoding())
+
+ # Sometimes nvme-cli may format the device successfully but fail to
+ # rescan the namespaces after the format. Continue if this happens but
+ # abort if some other error occurs.
+ if format_cmd_result.returncode != 0:
+ if 'failed to rescan namespaces' not in format_cmd_result.stderr \
+ or 'Success formatting namespace' not in format_cmd_result.stdout:
+ logging.error(format_cmd_result.stdout)
+ logging.error(format_cmd_result.stderr)
+ print("Unable to format device; skipping this configuration")
+ return False
+
+ logging.debug(format_cmd_result.stdout)
+ return True
+
+
+def parse_args():
+ """Parse command-line arguments."""
+
+ parser = argparse.ArgumentParser()
+ parser.add_argument('-d', '--debug', help='Enable debug messages', action='store_true')
+ parser.add_argument('-f', '--fio', help='path to file executable (e.g., ./fio)')
+ parser.add_argument('-a', '--artifact-root', help='artifact root directory')
+ parser.add_argument('-s', '--skip', nargs='+', type=int,
+ help='list of test(s) to skip')
+ parser.add_argument('-o', '--run-only', nargs='+', type=int,
+ help='list of test(s) to run, skipping all others')
+ parser.add_argument('--dut', help='target device to test '
+ '(e.g., /dev/nvme1n1). WARNING: THIS IS A DESTRUCTIVE TEST', required=True)
+ parser.add_argument('-l', '--lbaf', nargs='+', type=int,
+ help='list of lba formats to test')
+ args = parser.parse_args()
+
+ return args
+
+
+def difdix_test(test_env, args, lbaf, pitype):
+ """
+ Adjust test arguments based on values of lbaf, and pitype. Then run
+ the tests.
+ """
+ for test in TEST_LIST:
+ test['force_skip'] = False
+
+ blocksize = lbaf['ds']
+ # Set fio blocksize parameter at runtime
+ test['fio_opts']['md_per_io_size'] = lbaf['ms'] * test['bs_high']
+
+ test['fio_opts']['bsrange'] = f"{blocksize * test['bs_low']}-{blocksize * test['bs_high']}"
+
+ # Set fio pi_chk parameter at runtime. If the device is formatted
+ # with Type 3 protection information, this means that the reference
+ # tag is not checked and I/O commands may throw an error if they
+ # are submitted with the REFTAG bit set in pi_chk. Make sure fio
+ # does not set pi_chk's REFTAG bit if the device is formatted with
+ # Type 3 PI.
+ if 'pi_chk' in test:
+ if pitype == 3 and 'REFTAG' in test['pi_chk']:
+ test['fio_opts']['pi_chk'] = test['pi_chk'].replace('REFTAG','')
+ logging.debug("Type 3 PI: dropping REFTAG bit")
+ else:
+ test['fio_opts']['pi_chk'] = test['pi_chk']
+
+ logging.debug("Test %d: pi_act=%d, bsrange=%s, md_per_io_size=%d", test['test_id'],
+ test['fio_opts']['pi_act'], test['fio_opts']['bsrange'],
+ test['fio_opts']['md_per_io_size'])
+
+ return run_fio_tests(TEST_LIST, test_env, args)
+
+
+def main():
+ args = parse_args()
+
+ if args.debug:
+ logging.basicConfig(level=logging.DEBUG)
+ else:
+ logging.basicConfig(level=logging.INFO)
+
+ artifact_root = args.artifact_root if args.artifact_root else \
+ f"io_uring_pi-test-{time.strftime('%Y%m%d-%H%M%S')}"
+ os.mkdir(artifact_root)
+ print(f"Artifact directory is {artifact_root}")
+
+ if args.fio:
+ fio_path = str(Path(args.fio).absolute())
+ else:
+ fio_path = os.path.join(os.path.dirname(__file__), '../fio')
+ print(f"fio path is {fio_path}")
+
+ lbaf_list = get_lbafs(args)
+ get_guard_pi(lbaf_list, args)
+ caps = get_capabilities(args)
+ print("Device capabilities:", caps)
+
+ for test in TEST_LIST:
+ test['fio_opts']['filename'] = args.dut
+ test_env = {
+ 'fio_path': fio_path,
+ 'fio_root': str(Path(__file__).absolute().parent.parent),
+ 'artifact_root': artifact_root,
+ 'basename': 'io_uring_pi',
+ }
+
+ total = { 'passed': 0, 'failed': 0, 'skipped': 0 }
+
+ try:
+ for lbaf, pil, pitype in itertools.product(lbaf_list, caps['pil'], caps['pitype']):
+ if lbaf['ms'] == 0:
+ continue
+
+ print("\n")
+ print("-" * 120)
+ print(f"lbaf: {lbaf}, pil: {pil}, pitype: {pitype}")
+ print("-" * 120)
+
+ if not format_device(args, lbaf, pitype, pil, 0):
+ print("Formatting failed")
+ continue
+
+ test_env['artifact_root'] = \
+ os.path.join(artifact_root, f"lbaf{lbaf['lbaf']}pil{pil}pitype{pitype}")
+ os.mkdir(test_env['artifact_root'])
+
+ passed, failed, skipped = difdix_test(test_env, args, lbaf, pitype)
+
+ total['passed'] += passed
+ total['failed'] += failed
+ total['skipped'] += skipped
+
+ except KeyboardInterrupt:
+ pass
+
+ print(f"\n\n{total['passed']} test(s) passed, {total['failed']} failed, " \
+ f"{total['skipped']} skipped")
+ sys.exit(total['failed'])
+
+
+if __name__ == '__main__':
+ main()
--
2.47.2