openstack/nova
Code Issues Proposed changes

Adds "file" disk driver support to Xen libvirt driver.

Browse Source 
There are Xen servers which do not support
http://wiki.xen.org/wiki/Blktap (e.g. Oracle VM Server for x86) but
are still operational with simple file driver. So, if Xen node do not
support Blktap then method pick_disk_driver_name return "file" instead
of "tap" or "tap2" in case of "qemu" is not available.

Change-Id: If8fbb058ed7e78e4a80d54f0561e2d8b9055ecb9
Partial-Bug: #1323722
This commit is contained in:
Nikita Gerasimov 2015-01-12 20:01:05 +03:00
parent 9595d09e05
commit 09f8089a9a
2 changed files with 84 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

67
nova/tests/unit/virt/libvirt/test_utils.py
View File

@ -336,31 +336,70 @@ ID TAG VM SIZE DATE VM CLOCK
def test_pick_disk_driver_name(self):
type_map = {'kvm': ([True, 'qemu'], [False, 'qemu'], [None, 'qemu']),
'qemu': ([True, 'qemu'], [False, 'qemu'], [None, 'qemu']),
'xen': ([True, 'phy'], [False, 'qemu'], [None, 'qemu']),
'uml': ([True, None], [False, None], [None, None]),
'lxc': ([True, None], [False, None], [None, None])}
# NOTE(aloga): Xen is tested in test_pick_disk_driver_name_xen
version = 1005001
for (virt_type, checks) in type_map.iteritems():
if virt_type == "xen":
# NOTE(aloga): Xen is tested in test_pick_disk_driver_name_xen
version = 4004000
else:
version = 1005001
self.flags(virt_type=virt_type, group='libvirt')
for (is_block_dev, expected_result) in checks:
result = libvirt_utils.pick_disk_driver_name(version,
is_block_dev)
self.assertEqual(result, expected_result)
def test_pick_disk_driver_name_xen(self):
version_map = ((4000000, "tap"),
(4001000, "tap2"),
(4002000, "qemu"))
@mock.patch('nova.utils.execute')
def test_pick_disk_driver_name_xen(self, mock_execute):
def side_effect(*args, **kwargs):
if args == ('tap-ctl', 'check'):
if mock_execute.blktap is True:
return ('ok\n', '')
elif mock_execute.blktap is False:
return ('some error\n', '')
else:
raise OSError(2, "No such file or directory")
elif args == ('xend', 'status'):
if mock_execute.xend is True:
return ('', '')
elif mock_execute.xend is False:
raise processutils.ProcessExecutionError("error")
else:
raise OSError(2, "No such file or directory")
raise Exception('Unexpected call')
mock_execute.side_effect = side_effect
self.flags(virt_type="xen", group='libvirt')
for ver, drv in version_map:
result = libvirt_utils.pick_disk_driver_name(ver, False)
self.assertEqual(drv, result)
versions = [4000000, 4001000, 4002000, 4003000, 4005000]
for version in versions:
# block dev
result = libvirt_utils.pick_disk_driver_name(version, True)
self.assertEqual(result, "phy")
self.assertFalse(mock_execute.called)
mock_execute.reset_mock()
# file dev
for blktap in True, False, None:
mock_execute.blktap = blktap
for xend in True, False, None:
mock_execute.xend = xend
result = libvirt_utils.pick_disk_driver_name(version,
False)
# qemu backend supported only by libxl which is
# production since xen 4.2. libvirt use libxl if
# xend service not started.
if version >= 4002000 and xend is not True:
self.assertEqual(result, 'qemu')
elif blktap:
if version == 4000000:
self.assertEqual(result, 'tap')
else:
self.assertEqual(result, 'tap2')
else:
self.assertEqual(result, 'file')
# default is_block_dev False
self.assertEqual(result,
libvirt_utils.pick_disk_driver_name(version))
mock_execute.reset_mock()
@mock.patch('os.path.exists', return_value=True)
@mock.patch('nova.utils.execute')

38
nova/virt/libvirt/utils.py
View File

@ -223,13 +223,37 @@ def pick_disk_driver_name(hypervisor_version, is_block_dev=False):
else:
# 4002000 == 4.2.0
if hypervisor_version >= 4002000:
return 'qemu'
# 4000000 == 4.0.0
elif hypervisor_version > 4000000:
return "tap2"
else:
return "tap"
try:
execute('xend', 'status',
run_as_root=True, check_exit_code=True)
except OSError as exc:
if exc.errno == errno.ENOENT:
LOG.debug("xend is not found")
# libvirt will try to use libxl toolstack
return 'qemu'
else:
raise
except processutils.ProcessExecutionError as exc:
LOG.debug("xend is not started")
# libvirt will try to use libxl toolstack
return 'qemu'
# libvirt will use xend/xm toolstack
try:
out, err = execute('tap-ctl', 'check', check_exit_code=False)
if out == 'ok\n':
# 4000000 == 4.0.0
if hypervisor_version > 4000000:
return "tap2"
else:
return "tap"
else:
LOG.info(_LI("tap-ctl check: %s"), out)
except OSError as exc:
if exc.errno == errno.ENOENT:
LOG.debug("tap-ctl tool is not installed")
else:
raise
return "file"
elif CONF.libvirt.virt_type in ('kvm', 'qemu'):
return "qemu"
else: