From c5dfcafe0329aab03290e0eb642a86f9d5ba699d Mon Sep 17 00:00:00 2001 From: Lee Yarwood Date: Wed, 5 Aug 2020 23:00:06 +0100 Subject: [PATCH] libvirt: Provide VIR_MIGRATE_PARAM_PERSIST_XML during live migration The VIR_MIGRATE_PARAM_PERSIST_XML parameter was introduced in libvirt v1.3.4 and is used to provide the new persistent configuration for the destination during a live migration: https://libvirt.org/html/libvirt-libvirt-domain.html#VIR_MIGRATE_PARAM_PERSIST_XML Without this parameter the persistent configuration on the destination will be the same as the original persistent configuration on the source when the VIR_MIGRATE_PERSIST_DEST flag is provided. As Nova does not currently provide the VIR_MIGRATE_PARAM_PERSIST_XML param but does provide the VIR_MIGRATE_PERSIST_DEST flag this means that a soft reboot by Nova of the instance after a live migration can revert the domain back to the original persistent configuration from the source. Note that this is only possible in Nova as a soft reboot actually results in the virDomainShutdown and virDomainLaunch libvirt APIs being called that recreate the domain using the persistent configuration. virDomainReboot does not result in this but is not called at this time. The impact of this on the instance after the soft reboot is pretty severe, host devices referenced in the original persistent configuration on the source may not exist or could even be used by other users on the destination. CPU and NUMA affinity could also differ drastically between the two hosts resulting in the instance being unable to start etc. As MIN_LIBVIRT_VERSION is now > v1.3.4 this change simply includes the VIR_MIGRATE_PARAM_PERSIST_XML param using the same updated XML for the destination as is already provided to VIR_MIGRATE_PARAM_DEST_XML. Co-authored-by: Tadayoshi Hosoya Closes-Bug: #1890501 Change-Id: Ia3f1d8e83cbc574ce5cb440032e12bbcb1e10e98 (cherry picked from commit 573943a2d08995eef72f203ca69a2e23c3373e65) (cherry picked from commit 916f9ba823e2eba307c951d84121ff39d7126bb5) --- nova/tests/unit/virt/libvirt/test_driver.py | 8 +++++++- nova/tests/unit/virt/libvirt/test_guest.py | 2 ++ nova/virt/libvirt/guest.py | 1 + 3 files changed, 10 insertions(+), 1 deletion(-) diff --git a/nova/tests/unit/virt/libvirt/test_driver.py b/nova/tests/unit/virt/libvirt/test_driver.py index 595fdc1526..1637d95810 100644 --- a/nova/tests/unit/virt/libvirt/test_driver.py +++ b/nova/tests/unit/virt/libvirt/test_driver.py @@ -10875,6 +10875,7 @@ class LibvirtConnTestCase(test.NoDBTestCase, 'migrate_disks': disk_paths, 'bandwidth': _bandwidth, 'destination_xml': target_xml, + 'persistent_xml': target_xml, } # start test @@ -10982,7 +10983,8 @@ class LibvirtConnTestCase(test.NoDBTestCase, 'migrate_disks': disk_paths, 'migrate_uri': 'tcp://127.0.0.2', 'bandwidth': CONF.libvirt.live_migration_bandwidth, - 'destination_xml': target_xml + 'destination_xml': target_xml, + 'persistent_xml': target_xml, } # Start test @@ -11139,6 +11141,7 @@ class LibvirtConnTestCase(test.NoDBTestCase, 'migrate_uri': 'tcp://127.0.0.2', 'bandwidth': CONF.libvirt.live_migration_bandwidth, 'destination_xml': target_xml, + 'persistent_xml': target_xml, } # start test @@ -11490,6 +11493,7 @@ class LibvirtConnTestCase(test.NoDBTestCase, 'migrate_disks': ['vda', 'vdb'], 'bandwidth': CONF.libvirt.live_migration_bandwidth, 'destination_xml': target_xml, + 'persistent_xml': target_xml, } # start test @@ -11616,6 +11620,7 @@ class LibvirtConnTestCase(test.NoDBTestCase, 'migrate_disks': device_names, 'bandwidth': CONF.libvirt.live_migration_bandwidth, 'destination_xml': '', + 'persistent_xml': '', } if not params['migrate_disks']: del params['migrate_disks'] @@ -11755,6 +11760,7 @@ class LibvirtConnTestCase(test.NoDBTestCase, 'migrate_disks': disk_paths, 'bandwidth': CONF.libvirt.live_migration_bandwidth, 'destination_xml': '', + 'persistent_xml': '', } # Prepare mocks diff --git a/nova/tests/unit/virt/libvirt/test_guest.py b/nova/tests/unit/virt/libvirt/test_guest.py index b11a5f46a1..06d3a2a802 100644 --- a/nova/tests/unit/virt/libvirt/test_guest.py +++ b/nova/tests/unit/virt/libvirt/test_guest.py @@ -699,6 +699,7 @@ class GuestTestCase(test.NoDBTestCase): 'an-uri', flags=1, params={'migrate_uri': 'dest-uri', 'migrate_disks': 'disk1', 'destination_xml': '', + 'persistent_xml': '', 'bandwidth': 2}) @testtools.skipIf(not six.PY2, 'libvirt python3 bindings accept unicode') @@ -716,6 +717,7 @@ class GuestTestCase(test.NoDBTestCase): 'migrate_disks': ['disk1', 'disk2'], 'destination_xml': expect_dest_xml, + 'persistent_xml': expect_dest_xml, 'bandwidth': 2}) def test_abort_job(self): diff --git a/nova/virt/libvirt/guest.py b/nova/virt/libvirt/guest.py index 976bca2717..98c8c84e6e 100644 --- a/nova/virt/libvirt/guest.py +++ b/nova/virt/libvirt/guest.py @@ -642,6 +642,7 @@ class Guest(object): if destination_xml: params['destination_xml'] = destination_xml + params['persistent_xml'] = destination_xml if migrate_disks: params['migrate_disks'] = migrate_disks if migrate_uri: -- 2.26.2