nova-solver-scheduler/nova_solverscheduler/scheduler/solvers/constraints/pci_passthrough_constraint.py

82 lines
3.3 KiB
Python

# Copyright (c) 2011-2012 OpenStack Foundation
# All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
import copy
from oslo_log import log as logging
from nova.i18n import _
from nova_solverscheduler.scheduler.solvers import constraints
LOG = logging.getLogger(__name__)
class PciPassthroughConstraint(constraints.BaseLinearConstraint):
"""Constraint that schedules instances on a host if the host has devices
to meet the device requests in the 'extra_specs' for the flavor.
PCI resource tracker provides updated summary information about the
PCI devices for each host, like:
[{"count": 5, "vendor_id": "8086", "product_id": "1520",
"extra_info":'{}'}],
and VM requests PCI devices via PCI requests, like:
[{"count": 1, "vendor_id": "8086", "product_id": "1520",}].
The constraint checks if the host passes or not based on this information.
"""
def _get_acceptable_pci_requests_times(self, max_times_to_try,
pci_requests, host_pci_stats):
acceptable_times = 0
while acceptable_times < max_times_to_try:
if host_pci_stats.support_requests(pci_requests):
acceptable_times += 1
host_pci_stats.apply_requests(pci_requests)
else:
break
return acceptable_times
def get_constraint_matrix(self, hosts, filter_properties):
num_hosts = len(hosts)
num_instances = filter_properties.get('num_instances')
constraint_matrix = [[True for j in xrange(num_instances)]
for i in xrange(num_hosts)]
pci_requests = filter_properties.get('pci_requests')
if not pci_requests:
LOG.warn(_("PciPassthroughConstraint check is skipped because "
"requested instance PCI requests is unavailable."))
return constraint_matrix
for i in xrange(num_hosts):
host_pci_stats = copy.deepcopy(hosts[i].pci_stats)
acceptable_num_instances = (
self._get_acceptable_pci_requests_times(num_instances,
pci_requests, host_pci_stats))
if acceptable_num_instances < num_instances:
inacceptable_num = num_instances - acceptable_num_instances
constraint_matrix[i] = (
[True for j in xrange(acceptable_num_instances)] +
[False for j in xrange(inacceptable_num)])
LOG.debug(_("%(host)s can accept %(num)s requested instances "
"according to PciPassthroughConstraint."),
{'host': hosts[i],
'num': acceptable_num_instances})
return constraint_matrix