#!/usr/bin/python3
#
# Copyright (C) 2022 Canonical, Ltd.
# Author: Lukas Märdian <slyon@ubuntu.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; version 3.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
'''netplan SR-IOV rebind command line'''
import logging
import os
import sys
from time import sleep
from .. import utils
from ..sriov import PCIDevice, bind_vfs, _get_pci_slot_name
import netplan
FALLBACK_WAIT_TIME_SEC = 3
INTERVAL_SEC = 0.2
MAX_WAITING_TIME_SEC = 5
class MLX5VFLAGStateNotFound(Exception):
pass
class MLX5VFLAGStateCannotBeRead(Exception):
pass
class MLX5VFLAGStateDisabled(Exception):
pass
class NetplanSriovRebind(utils.NetplanCommand):
def __init__(self):
super().__init__(command_id='rebind',
description='Rebind SR-IOV virtual functions of given physical functions to their driver',
leaf=True)
def run(self):
self.parser.add_argument('--root-dir', default='/',
help='Search for configuration files in this root directory instead of /')
self.parser.add_argument('netdevs', type=str, nargs='*', default=[],
help='Space separated list of PF interface names')
self.func = self.command_rebind
self.logger = logging.getLogger('sriov_rebind')
self.logger.propagate = False
log_handler = logging.StreamHandler(stream=sys.stdout)
self.parse_args()
# netplan rebind --debug setup
if self.debug:
self.logger.setLevel(logging.DEBUG)
log_handler.setLevel(logging.DEBUG)
log_handler.setFormatter(logging.Formatter('%(levelname)s:%(message)s'))
else:
self.logger.setLevel(logging.INFO)
log_handler.setLevel(logging.INFO)
log_handler.setFormatter(logging.Formatter('%(message)s'))
self.logger.addHandler(log_handler)
self.run_command()
def command_rebind(self):
"""Bind virtual functions of SR-IOV devices to their corresponding driver after eswitch mode was changed"""
for iface in self.netdevs:
pci_addr = _get_pci_slot_name(iface)
pcidev = PCIDevice(pci_addr)
if not pcidev.is_pf:
self.logger.debug('{} does not seem to be a SR-IOV physical function'.format(iface))
continue
# There are some hardware-specific configuration that must happen *before* the bind
# of VFs to their drivers. Some settings take time to be effective and, when possible,
# we need to wait until the driver reports it's ready.
self._perform_hardware_specific_quirks(iface, pcidev)
bound_vfs = bind_vfs(pcidev.vfs, pcidev.driver)
self.logger.debug('{}: bound {} VFs'.format(pcidev, len(bound_vfs)))
def _perform_hardware_specific_quirks(self, iface: str, pf: PCIDevice):
"""
Perform any hardware-specific quirks for the given SR-IOV device to make
sure it's ready before the bind.
"""
if pf.driver in ['mlx5_core']:
# Mellanox specific quirks
parser = netplan.Parser()
parser.load_yaml_hierarchy(self.root_dir)
np_state = netplan.State()
np_state.import_parser_results(parser)
for netdef in np_state.ethernets.values():
if (netdef._has_match and netdef.set_name == iface) or netdef.id == iface:
if bond_link := netdef.links.get('bond'):
# VF LAG support. See LP: #1988018
# If the PF is a member of a bond, the user might be trying to enable the
# VF LAG feature.
# Mellanox VF LAG requires that the LAG state reports as 'active'
# *before* VFs can be bound to the driver. Performing the bind operation
# before the device is ready will cause the VF LAG feature to never be enabled.
# Another condition for the VF LAG activation is that the LAG mode
# must be one of 'active-backup', 'balanced-xor' or '802.3ad'.
bond_mode = bond_link._bond_mode
if not self._is_bond_mode_supported(bond_mode):
self.logger.debug(f'{iface} - LAG mode {bond_mode} is not supported by VF LAG')
continue
self.logger.debug(f'{iface} - waiting for the LAG state to be \'active\'')
try:
self._wait_for_mlx5_pf_lag_state_active(pf)
except MLX5VFLAGStateCannotBeRead:
self.logger.debug(f'{iface} - VF LAG state cannot be read')
except MLX5VFLAGStateNotFound:
self.logger.debug(f'{iface} - VF LAG state debugfs file not found')
except MLX5VFLAGStateDisabled:
self.logger.debug(f'{iface} - VF LAG state is still \'disabled\' after waiting')
else:
self.logger.debug(f'{iface} - VF LAG state is \'active\'')
def _wait_for_mlx5_pf_lag_state_active(self, pf: PCIDevice):
"""
The mlx5 driver added support for debugfs in https://github.com/torvalds/linux/commit/7f46a0b7327a
It's available since kernel 5.19 https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.19
"""
retries = int(MAX_WAITING_TIME_SEC / INTERVAL_SEC)
pci_addr = pf.pci_addr
path = f'/sys/kernel/debug/mlx5/{pci_addr}/lag/state'
if not os.path.exists(path):
# If the debugfs file doesn't exist, it might be because this version of the mlx5 driver
# still doesn't support it or because the debugfs is not mounted.
# In this case, we probably should still wait for a few seconds to give time for the
# driver to change state.
# Based on tests with a ConnectX-5 NIC, 1 second is enough time, so let's wait a bit more
# just in case. This delay will only be introduced if the PF is part of a bond.
sleep(FALLBACK_WAIT_TIME_SEC)
raise MLX5VFLAGStateNotFound
while retries > 0:
try:
if self._get_mlx5_vf_lag_state(pci_addr) != 'active':
self.logger.debug(f'{pci_addr} VF LAG state is not active yet, retrying...')
# Based on tests with a ConnectX-5 NIC, a single 1-second cycle was enough time to
# allow the interfaces to change state.
sleep(INTERVAL_SEC)
else:
return
except Exception:
raise MLX5VFLAGStateCannotBeRead
retries = retries - 1
raise MLX5VFLAGStateDisabled
def _is_bond_mode_supported(self, mode: str) -> bool:
'''
Return True or False if the bond mode is one of the supported modes
for the VG LAG activation.
'''
return mode in ['active-backup', 'balanced-xor', '802.3ad']
def _get_mlx5_vf_lag_state(self, pci_addr: str) -> str:
path = f'/sys/kernel/debug/mlx5/{pci_addr}/lag/state'
with open(path, 'r') as f:
return f.read().strip()
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