/
host.py
569 lines (488 loc) · 23.1 KB
/
host.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
# Copyright (c) 2012 Citrix Systems, Inc.
# Copyright 2010 OpenStack Foundation
#
# 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.
"""
Management class for host-related functions (start, reboot, etc).
"""
import re
from os_xenapi.client import host_management
from os_xenapi.client import XenAPI
from oslo_config import cfg
from oslo_log import log as logging
from oslo_serialization import jsonutils
from nova.compute import task_states
from nova.compute import vm_states
from nova import context
from nova import exception
from nova.i18n import _
from nova import objects
from nova.objects import fields as obj_fields
from nova.virt.xenapi import pool_states
from nova.virt.xenapi import vm_utils
CONF = cfg.CONF
LOG = logging.getLogger(__name__)
class Host(object):
"""Implements host related operations."""
def __init__(self, session, virtapi):
self._session = session
self._virtapi = virtapi
def host_power_action(self, action):
"""Reboots or shuts down the host."""
args = {"action": jsonutils.dumps(action)}
methods = {"reboot": "host_reboot", "shutdown": "host_shutdown"}
response = call_xenhost(self._session, methods[action], args)
return response.get("power_action", response)
def host_maintenance_mode(self, host, mode):
"""Start/Stop host maintenance window. On start, it triggers
guest VMs evacuation.
"""
if not mode:
return 'off_maintenance'
host_list = [host_ref for host_ref in
self._session.host.get_all()
if host_ref != self._session.host_ref]
migrations_counter = vm_counter = 0
ctxt = context.get_admin_context()
for vm_ref, vm_rec in vm_utils.list_vms(self._session):
for host_ref in host_list:
try:
# Ensure only guest instances are migrated
uuid = vm_rec['other_config'].get('nova_uuid')
if not uuid:
name = vm_rec['name_label']
uuid = _uuid_find(ctxt, host, name)
if not uuid:
LOG.info('Instance %(name)s running on '
'%(host)s could not be found in '
'the database: assuming it is a '
'worker VM and skip ping migration '
'to a new host',
{'name': name, 'host': host})
continue
instance = objects.Instance.get_by_uuid(ctxt, uuid)
vm_counter = vm_counter + 1
aggregate = objects.AggregateList.get_by_host(
ctxt, host, key=pool_states.POOL_FLAG)
if not aggregate:
msg = _('Aggregate for host %(host)s count not be'
' found.') % dict(host=host)
raise exception.NotFound(msg)
dest = _host_find(ctxt, self._session, aggregate[0],
host_ref)
instance.host = dest
instance.task_state = task_states.MIGRATING
instance.save()
self._session.VM.pool_migrate(vm_ref, host_ref,
{"live": "true"})
migrations_counter = migrations_counter + 1
instance.vm_state = vm_states.ACTIVE
instance.save()
break
except XenAPI.Failure:
LOG.exception(_('Unable to migrate VM %(vm_ref)s '
'from %(host)s'),
{'vm_ref': vm_ref, 'host': host})
instance.host = host
instance.vm_state = vm_states.ACTIVE
instance.save()
if vm_counter == migrations_counter:
return 'on_maintenance'
else:
raise exception.NoValidHost(reason=_('Unable to find suitable '
'host for VMs evacuation'))
def set_host_enabled(self, enabled):
"""Sets the compute host's ability to accept new instances."""
# Since capabilities are gone, use service table to disable a node
# in scheduler
cntxt = context.get_admin_context()
service = objects.Service.get_by_args(cntxt, CONF.host,
'nova-compute')
service.disabled = not enabled
service.disabled_reason = 'set by xenapi host_state'
service.save()
response = _call_host_management(self._session,
host_management.set_host_enabled,
jsonutils.dumps(enabled))
return response.get("status", response)
def get_host_uptime(self):
"""Returns the result of calling "uptime" on the target host."""
response = _call_host_management(self._session,
host_management.get_host_uptime)
return response.get("uptime", response)
class HostState(object):
"""Manages information about the XenServer host this compute
node is running on.
"""
def __init__(self, session):
super(HostState, self).__init__()
self._session = session
self._stats = {}
self.update_status()
def _get_passthrough_devices(self):
"""Get a list pci devices that are available for pci passthtough.
We use a plugin to get the output of the lspci command runs on dom0.
From this list we will extract pci devices that are using the pciback
kernel driver.
:returns: a list of pci devices on the node
"""
def _compile_hex(pattern):
"""Return a compiled regular expression pattern into which we have
replaced occurrences of hex by [\da-fA-F].
"""
return re.compile(pattern.replace("hex", r"[\da-fA-F]"))
def _parse_pci_device_string(dev_string):
"""Exctract information from the device string about the slot, the
vendor and the product ID. The string is as follow:
"Slot:\tBDF\nClass:\txxxx\nVendor:\txxxx\nDevice:\txxxx\n..."
Return a dictionary with information about the device.
"""
slot_regex = _compile_hex(r"Slot:\t"
r"((?:hex{4}:)?" # Domain: (optional)
r"hex{2}:" # Bus:
r"hex{2}\." # Device.
r"hex{1})") # Function
vendor_regex = _compile_hex(r"\nVendor:\t(hex+)")
product_regex = _compile_hex(r"\nDevice:\t(hex+)")
slot_id = slot_regex.findall(dev_string)
vendor_id = vendor_regex.findall(dev_string)
product_id = product_regex.findall(dev_string)
if not slot_id or not vendor_id or not product_id:
raise exception.NovaException(
_("Failed to parse information about"
" a pci device for passthrough"))
type_pci = host_management.get_pci_type(self._session, slot_id[0])
return {'label': '_'.join(['label',
vendor_id[0],
product_id[0]]),
'vendor_id': vendor_id[0],
'product_id': product_id[0],
'address': slot_id[0],
'dev_id': '_'.join(['pci', slot_id[0]]),
'dev_type': type_pci,
'status': 'available'}
# Devices are separated by a blank line. That is why we
# use "\n\n" as separator.
lspci_out = host_management.get_pci_device_details(self._session)
pci_list = lspci_out.split("\n\n")
# For each device of the list, check if it uses the pciback
# kernel driver and if it does, get information and add it
# to the list of passthrough_devices. Ignore it if the driver
# is not pciback.
passthrough_devices = []
for dev_string_info in pci_list:
if "Driver:\tpciback" in dev_string_info:
new_dev = _parse_pci_device_string(dev_string_info)
passthrough_devices.append(new_dev)
return passthrough_devices
def _get_vgpu_stats(self):
"""Invoke XenAPI to get the stats for VGPUs.
The return value is a dict which has GPU groups' uuid as
the keys:
dict(grp_uuid_1=dict_vgpu_stats_in_grp_1,
grp_uuid_2=dict_vgpu_stats_in_grp_2,
...,
grp_uuid_n=dict_vgpu_stats_in_grp_n)
The `dict_vgpu_stats_in_grp_x` is a dict represents the
vGPU stats in GPU group x. For details, please refer to
the return value of the function of _get_vgpu_stats_in_group().
"""
if not CONF.devices.enabled_vgpu_types:
return {}
vgpu_stats = {}
# NOTE(jianghuaw): If there are multiple vGPU types enabled in
# the configure option, we only choose the first one so that
# we support only one vGPU type per compute node at the moment.
# Once we switch to use the nested resource providers, we will
# remove these lines to allow multiple vGPU types within multiple
# GPU groups (each group has a different vGPU type enabled).
if len(CONF.devices.enabled_vgpu_types) > 1:
LOG.warning('XenAPI only supports one GPU type per compute node,'
' only first type will be used.')
cfg_enabled_types = CONF.devices.enabled_vgpu_types[:1]
vgpu_grp_refs = self._session.call_xenapi('GPU_group.get_all')
for ref in vgpu_grp_refs:
grp_uuid = self._session.call_xenapi('GPU_group.get_uuid', ref)
stat = self._get_vgpu_stats_in_group(ref, cfg_enabled_types)
if stat:
vgpu_stats[grp_uuid] = stat
LOG.debug("Returning vGPU stats: %s", vgpu_stats)
return vgpu_stats
def _get_vgpu_stats_in_group(self, grp_ref, vgpu_types):
"""Get stats for the specified vGPU types in a GPU group.
NOTE(Jianghuaw): In XenAPI, a GPU group is the minimal unit
from where to create a vGPU for an instance. So here, we
report vGPU resources for a particular GPU group. When we use
nested resource providers to represent the vGPU resources,
each GPU group will be a child resource provider under the
compute node.
The return value is a dict. For example:
{'uuid': '6444c6ee-3a49-42f5-bebb-606b52175e67',
'type_name': 'Intel GVT-g',
'max_heads': 1,
'total': 7,
'remaining': 7,
}
"""
type_refs_in_grp = self._session.call_xenapi(
'GPU_group.get_enabled_VGPU_types', grp_ref)
type_names_in_grp = {self._session.call_xenapi(
'VGPU_type.get_model_name',
type_ref): type_ref
for type_ref in type_refs_in_grp}
# Get the vGPU types enabled both in this GPU group and in the
# nova conf.
enabled_types = set(vgpu_types) & set(type_names_in_grp)
if not enabled_types:
return
stat = {}
# Get the sorted enabled types, so that we can always choose the same
# type when there are multiple enabled vGPU types.
sorted_types = sorted(enabled_types)
chosen_type = sorted_types[0]
if len(sorted_types) > 1:
LOG.warning('XenAPI only supports one vGPU type per GPU group,'
' but enabled multiple vGPU types: %(available)s.'
' Choosing the first one: %(chosen)s.',
dict(available=sorted_types,
chosen=chosen_type))
type_ref = type_names_in_grp[chosen_type]
type_uuid = self._session.call_xenapi('VGPU_type.get_uuid', type_ref)
stat['uuid'] = type_uuid
stat['type_name'] = chosen_type
stat['max_heads'] = int(self._session.call_xenapi(
'VGPU_type.get_max_heads', type_ref))
stat['total'] = self._get_total_vgpu_in_grp(grp_ref, type_ref)
stat['remaining'] = int(self._session.call_xenapi(
'GPU_group.get_remaining_capacity',
grp_ref,
type_ref))
return stat
def _get_total_vgpu_in_grp(self, grp_ref, type_ref):
"""Get the total capacity of vGPUs in the group."""
pgpu_recs = self._session.call_xenapi(
'PGPU.get_all_records_where', 'field "GPU_group" = "%s"' % grp_ref)
total = 0
for pgpu_ref in pgpu_recs:
pgpu_rec = pgpu_recs[pgpu_ref]
if type_ref in pgpu_rec['enabled_VGPU_types']:
cap = pgpu_rec['supported_VGPU_max_capacities'][type_ref]
total += int(cap)
return total
def get_host_stats(self, refresh=False):
"""Return the current state of the host. If 'refresh' is
True, run the update first.
"""
if refresh or not self._stats:
self.update_status()
return self._stats
def get_disk_used(self, sr_ref):
"""Since glance images are downloaded and snapshotted before they are
used, only a small proportion of its VDI will be in use and it will
never grow. We only need to count the virtual size for disks that
are attached to a VM - every other disk can count physical.
"""
def _vdi_attached(vdi_ref):
try:
vbds = self._session.VDI.get_VBDs(vdi_ref)
for vbd in vbds:
if self._session.VBD.get_currently_attached(vbd):
return True
except self._session.XenAPI.Failure:
# VDI or VBD may no longer exist - in which case, it's
# not attached
pass
return False
allocated = 0
physical_used = 0
all_vdis = self._session.SR.get_VDIs(sr_ref)
for vdi_ref in all_vdis:
try:
vdi_physical = \
int(self._session.VDI.get_physical_utilisation(vdi_ref))
if _vdi_attached(vdi_ref):
allocated += \
int(self._session.VDI.get_virtual_size(vdi_ref))
else:
allocated += vdi_physical
physical_used += vdi_physical
except (ValueError, self._session.XenAPI.Failure):
LOG.exception(_('Unable to get size for vdi %s'), vdi_ref)
return (allocated, physical_used)
def update_status(self):
"""Since under Xenserver, a compute node runs on a given host,
we can get host status information using xenapi.
"""
LOG.debug("Updating host stats")
data = _call_host_management(self._session,
host_management.get_host_data)
if data:
sr_ref = vm_utils.scan_default_sr(self._session)
sr_rec = self._session.SR.get_record(sr_ref)
total = int(sr_rec["physical_size"])
(allocated, used) = self.get_disk_used(sr_ref)
data["disk_total"] = total
data["disk_used"] = used
data["disk_allocated"] = allocated
data["disk_available"] = total - used
data["supported_instances"] = to_supported_instances(
data.get("host_capabilities")
)
data["cpu_model"] = to_cpu_model(
data.get("host_cpu_info")
)
host_memory = data.get('host_memory', None)
if host_memory:
data["host_memory_total"] = host_memory.get('total', 0)
data["host_memory_overhead"] = host_memory.get('overhead', 0)
data["host_memory_free"] = host_memory.get('free', 0)
data["host_memory_free_computed"] = host_memory.get(
'free-computed', 0)
del data['host_memory']
if (data['host_hostname'] !=
self._stats.get('host_hostname', data['host_hostname'])):
LOG.error('Hostname has changed from %(old)s to %(new)s. '
'A restart is required to take effect.',
{'old': self._stats['host_hostname'],
'new': data['host_hostname']})
data['host_hostname'] = self._stats['host_hostname']
data['hypervisor_hostname'] = data['host_hostname']
vcpus_used = 0
for vm_ref, vm_rec in vm_utils.list_vms(self._session):
vcpus_used = vcpus_used + int(vm_rec['VCPUs_max'])
data['vcpus_used'] = vcpus_used
data['pci_passthrough_devices'] = self._get_passthrough_devices()
data['vgpu_stats'] = self._get_vgpu_stats()
self._stats = data
def to_supported_instances(host_capabilities):
if not host_capabilities:
return []
result = []
for capability in host_capabilities:
try:
# 'capability'is unicode but we want arch/ostype
# to be strings to match the standard constants
capability = str(capability)
ostype, _version, guestarch = capability.split("-")
guestarch = obj_fields.Architecture.canonicalize(guestarch)
ostype = obj_fields.VMMode.canonicalize(ostype)
result.append((guestarch, obj_fields.HVType.XEN, ostype))
except ValueError:
LOG.warning("Failed to extract instance support from %s",
capability)
return result
def to_cpu_model(host_cpu_info):
# The XenAPI driver returns data in the format
#
# {"physical_features": "0098e3fd-bfebfbff-00000001-28100800",
# "modelname": "Intel(R) Xeon(R) CPU X3430 @ 2.40GHz",
# "vendor": "GenuineIntel",
# "features": "0098e3fd-bfebfbff-00000001-28100800",
# "family": 6,
# "maskable": "full",
# "cpu_count": 4,
# "socket_count": "1",
# "flags": "fpu de tsc msr pae mce cx8 apic sep mtrr mca cmov
# pat clflush acpi mmx fxsr sse sse2 ss ht nx
# constant_tsc nonstop_tsc aperfmperf pni vmx est
# ssse3 sse4_1 sse4_2 popcnt hypervisor ida
# tpr_shadow vnmi flexpriority ept vpid",
# "stepping": 5,
# "model": 30,
# "features_after_reboot": "0098e3fd-bfebfbff-00000001-28100800",
# "speed": "2394.086"}
if host_cpu_info is None:
return None
cpu_info = dict()
# TODO(berrange) the data we're putting in model is not
# exactly comparable to what libvirt puts in model. The
# libvirt model names are a well defined short string
# which is really an aliass for a particular set of
# feature flags. The Xen model names are raw printable
# strings from the kernel with no specific semantics
cpu_info["model"] = host_cpu_info["modelname"]
cpu_info["vendor"] = host_cpu_info["vendor"]
# TODO(berrange) perhaps we could fill in 'arch' field too
# by looking at 'host_capabilities' for the Xen host ?
topology = dict()
topology["sockets"] = int(host_cpu_info["socket_count"])
topology["cores"] = (int(host_cpu_info["cpu_count"]) /
int(host_cpu_info["socket_count"]))
# TODO(berrange): if 'ht' is present in the 'flags' list
# is it possible to infer that the 'cpu_count' is in fact
# sockets * cores * threads ? Unclear if 'ht' would remain
# visible when threads are disabled in BIOS ?
topology["threads"] = 1
cpu_info["topology"] = topology
cpu_info["features"] = host_cpu_info["flags"].split(" ")
return cpu_info
def call_xenhost(session, method, arg_dict):
"""There will be several methods that will need this general
handling for interacting with the xenhost plugin, so this abstracts
out that behavior.
"""
# Create a task ID as something that won't match any instance ID
try:
result = session.call_plugin('xenhost.py', method, args=arg_dict)
if not result:
return ''
return jsonutils.loads(result)
except ValueError:
LOG.exception(_("Unable to get updated status"))
return None
except session.XenAPI.Failure as e:
LOG.error("The call to %(method)s returned "
"an error: %(e)s.", {'method': method, 'e': e})
return e.details[1]
def _call_host_management(session, method, *args):
"""There will be several methods that will need this general
handling for interacting with the dom0 plugin, so this abstracts
out that behavior. the call_xenhost will be removed once we deprecated
those functions which are not needed anymore
"""
try:
result = method(session, *args)
if not result:
return ''
return jsonutils.loads(result)
except ValueError:
LOG.exception(_("Unable to get updated status"))
return None
except session.XenAPI.Failure as e:
LOG.error("The call to %(method)s returned an error: %(e)s.",
{'method': method.__name__, 'e': e})
return e.details[1]
def _uuid_find(context, host, name_label):
"""Return instance uuid by name_label."""
for i in objects.InstanceList.get_by_host(context, host):
if i.name == name_label:
return i.uuid
return None
def _host_find(context, session, src_aggregate, host_ref):
"""Return the host from the xenapi host reference.
:param src_aggregate: the aggregate that the compute host being put in
maintenance (source of VMs) belongs to
:param host_ref: the hypervisor host reference (destination of VMs)
:return: the compute host that manages host_ref
"""
# NOTE: this would be a lot simpler if nova-compute stored
# CONF.host in the XenServer host's other-config map.
# TODO(armando-migliaccio): improve according the note above
uuid = session.host.get_uuid(host_ref)
for compute_host, host_uuid in src_aggregate.metadetails.items():
if host_uuid == uuid:
return compute_host
raise exception.NoValidHost(reason='Host %(host_uuid)s could not be found '
'from aggregate metadata: %(metadata)s.' %
{'host_uuid': uuid,
'metadata': src_aggregate.metadetails})