libvirt: set device address tag only if setting disk unit

In Pike, we began setting disk unit values manually for the
'virtio-scsi' controller model in order to allow up to 256 devices [1].
We do this by setting the disk unit of the address tag manually for the
guest config. If we do not set the address tag manually, libvirt would
autogenerate it for us.

A problem occurs when a user has a SCSI disk that is a volume or isn't
using the 'virtio-scsi' controller model because we're not guarding our
manual setting of the address tag in the guest config by the disk unit,
in addition to the SCSI bus. This means that for a SCSI volume, we
generate an address tag like '<address type="drive" controller="0"/>'
for any SCSI volume, so a user with more than one device will get the
following error when they try to boot an instance:

  Failed to start libvirt guest: libvirtError: unsupported
    configuration: Found duplicate drive address for disk with target name
    'sda' controller='0' bus='0' target='0' unit='0'

This updates the conditionals to only manually set the address tag if
the bus is SCSI _and_ the disk unit has been specified. Otherwise, let
libvirt autogenerate the address tag and take care of avoiding
collisions.

[1] https://bugs.launchpad.net/nova/+bug/1686116

Closes-Bug: #1792077

 Conflicts:
     nova/tests/unit/virt/libvirt/volume/test_volume.py

NOTE(melwitt): Conflict is due to not having change
Ibfa64f18bbd2fb70db7791330ed1a64fe61c1355 in Pike.

Change-Id: Iefab05e84ccc0bf8f15bdbbf515a290d282dbc5d
(cherry picked from commit 48fd81648a)
(cherry picked from commit 7500c1910c)
(cherry picked from commit 8703282508)
(cherry picked from commit c8ad9f4e19)
This commit is contained in:
melanie witt 2018-10-19 22:06:20 +00:00
parent 9191083211
commit b50b70a182
4 changed files with 73 additions and 10 deletions

View File

@ -20,6 +20,7 @@ import shutil
import tempfile
from castellan import key_manager
import ddt
import fixtures
import mock
from oslo_concurrency import lockutils
@ -56,6 +57,7 @@ class FakeConn(object):
return FakeSecret()
@ddt.ddt
class _ImageTestCase(object):
def mock_create_image(self, image):
@ -202,6 +204,24 @@ class _ImageTestCase(object):
self.assertEqual(2361393152, image.get_disk_size(image.path))
get_disk_size.assert_called_once_with(image.path)
def _test_libvirt_info_scsi_with_unit(self, disk_unit):
# The address should be set if bus is scsi and unit is set.
# Otherwise, it should not be set at all.
image = self.image_class(self.INSTANCE, self.NAME)
disk = image.libvirt_info(disk_bus='scsi', disk_dev='/dev/sda',
device_type='disk', cache_mode='none',
extra_specs={}, hypervisor_version=4004001,
disk_unit=disk_unit)
if disk_unit:
self.assertEqual(0, disk.device_addr.controller)
self.assertEqual(disk_unit, disk.device_addr.unit)
else:
self.assertIsNone(disk.device_addr)
@ddt.data(5, None)
def test_libvirt_info_scsi_with_unit(self, disk_unit):
self._test_libvirt_info_scsi_with_unit(disk_unit)
class FlatTestCase(_ImageTestCase, test.NoDBTestCase):
@ -1256,6 +1276,7 @@ class EncryptedLvmTestCase(_ImageTestCase, test.NoDBTestCase):
model)
@ddt.ddt
class RbdTestCase(_ImageTestCase, test.NoDBTestCase):
FSID = "FakeFsID"
POOL = "FakePool"
@ -1480,6 +1501,17 @@ class RbdTestCase(_ImageTestCase, test.NoDBTestCase):
super(RbdTestCase, self).test_libvirt_info()
@ddt.data(5, None)
@mock.patch.object(rbd_utils.RBDDriver, "get_mon_addrs")
def test_libvirt_info_scsi_with_unit(self, disk_unit, mock_mon_addrs):
def get_mon_addrs():
hosts = ["server1", "server2"]
ports = ["1899", "1920"]
return hosts, ports
mock_mon_addrs.side_effect = get_mon_addrs
super(RbdTestCase, self)._test_libvirt_info_scsi_with_unit(disk_unit)
@mock.patch.object(rbd_utils.RBDDriver, "get_mon_addrs")
def test_get_model(self, mock_mon_addrs):
pool = "FakePool"

View File

@ -13,6 +13,7 @@
# License for the specific language governing permissions and limitations
# under the License.
import ddt
import mock
from nova import exception
@ -129,6 +130,7 @@ class LibvirtISCSIVolumeBaseTestCase(LibvirtVolumeBaseTestCase):
return ret
@ddt.ddt
class LibvirtVolumeTestCase(LibvirtISCSIVolumeBaseTestCase):
def _assertDiskInfoEquals(self, tree, disk_info):
@ -303,3 +305,21 @@ class LibvirtVolumeTestCase(LibvirtISCSIVolumeBaseTestCase):
conf = libvirt_driver.get_config(connection_info, self.disk_info)
tree = conf.format_dom()
self.assertIsNone(tree.find("driver[@discard]"))
@ddt.data(5, None)
def test_libvirt_volume_driver_address_tag_scsi_unit(self, disk_unit):
# The address tag should be set if bus is scsi and unit is set.
# Otherwise, it should not be set at all.
libvirt_driver = volume.LibvirtVolumeDriver(self.fake_host)
connection_info = {'data': {'device_path': '/foo'}}
disk_info = {'bus': 'scsi', 'dev': 'sda', 'type': 'disk'}
if disk_unit:
disk_info['unit'] = disk_unit
conf = libvirt_driver.get_config(connection_info, disk_info)
tree = conf.format_dom()
address = tree.find('address')
if disk_unit:
self.assertEqual('0', address.attrib['controller'])
self.assertEqual(str(disk_unit), address.attrib['unit'])
else:
self.assertIsNone(address)

View File

@ -152,11 +152,17 @@ class Image(object):
return info
def disk_scsi(self, info, disk_unit):
# The driver is responsible to create the SCSI controller
# at index 0.
info.device_addr = vconfig.LibvirtConfigGuestDeviceAddressDrive()
info.device_addr.controller = 0
# NOTE(melwitt): We set the device address unit number manually in the
# case of the virtio-scsi controller, in order to allow attachment of
# up to 256 devices. So, we should only be setting the address tag
# if we intend to set the unit number. Otherwise, we will let libvirt
# handle autogeneration of the address tag.
# See https://bugs.launchpad.net/nova/+bug/1792077 for details.
if disk_unit is not None:
# The driver is responsible to create the SCSI controller
# at index 0.
info.device_addr = vconfig.LibvirtConfigGuestDeviceAddressDrive()
info.device_addr.controller = 0
# In order to allow up to 256 disks handled by one
# virtio-scsi controller, the device addr should be
# specified.

View File

@ -93,16 +93,21 @@ class LibvirtBaseVolumeDriver(object):
if data.get('discard', False) is True:
conf.driver_discard = 'unmap'
if disk_info['bus'] == 'scsi':
# NOTE(melwitt): We set the device address unit number manually in the
# case of the virtio-scsi controller, in order to allow attachment of
# up to 256 devices. So, we should only be setting the address tag
# if we intend to set the unit number. Otherwise, we will let libvirt
# handle autogeneration of the address tag.
# See https://bugs.launchpad.net/nova/+bug/1792077 for details.
if disk_info['bus'] == 'scsi' and 'unit' in disk_info:
# The driver is responsible to create the SCSI controller
# at index 0.
conf.device_addr = vconfig.LibvirtConfigGuestDeviceAddressDrive()
conf.device_addr.controller = 0
if 'unit' in disk_info:
# In order to allow up to 256 disks handled by one
# virtio-scsi controller, the device addr should be
# specified.
conf.device_addr.unit = disk_info['unit']
# In order to allow up to 256 disks handled by one
# virtio-scsi controller, the device addr should be
# specified.
conf.device_addr.unit = disk_info['unit']
return conf