On 1/14/20 2:46 PM, marcandre.lureau@redhat.com wrote:
From: Marc-André Lureau <marcandre.lureau@redhat.com>
Helper processes may have their state migrated with QEMU data stream thanks to the QEMU "dbus-vmstate".
libvirt maintains the list of helpers to be migrated. The "dbus-vmstate" is added when required, and given the list of helper Ids that must be migrated, on save & load sides.
See also: https://git.qemu.org/?p=qemu.git;a=blob;f=docs/interop/dbus-vmstate.rst
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> --- src/qemu/qemu_alias.c | 7 +++ src/qemu/qemu_alias.h | 2 + src/qemu/qemu_command.c | 62 +++++++++++++++++++++++++++ src/qemu/qemu_command.h | 3 ++ src/qemu/qemu_dbus.c | 14 ++++++ src/qemu/qemu_dbus.h | 4 ++ src/qemu/qemu_domain.c | 10 +++++ src/qemu/qemu_domain.h | 5 +++ src/qemu/qemu_hotplug.c | 82 ++++++++++++++++++++++++++++++++++++ src/qemu/qemu_hotplug.h | 8 ++++ src/qemu/qemu_migration.c | 51 ++++++++++++++++++++++ src/qemu/qemu_monitor.c | 21 +++++++++ src/qemu/qemu_monitor.h | 3 ++ src/qemu/qemu_monitor_json.c | 15 +++++++ src/qemu/qemu_monitor_json.h | 5 +++ 15 files changed, 292 insertions(+)
diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index 71d0bb0879..8c281f3a70 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -1125,10 +1125,18 @@ qemuMigrationSrcIsAllowed(virQEMUDriverPtr driver, bool remote, unsigned int flags) { + qemuDomainObjPrivatePtr priv = vm->privateData; int nsnapshots; int pauseReason; size_t i;
+ if (virStringListLength((const char **)priv->dbusVMStateIds) && + !virQEMUCapsGet(priv->qemuCaps, QEMU_CAPS_DBUS_VMSTATE)) { + virReportError(VIR_ERR_OPERATION_INVALID, "%s", + _("cannot migrate this domain without dbus-vmstate support")); + return false; + } +
This should be done in the if(!OFFLINE) a few lines below. IIUC, vmstate is runtime thing, and when doing offline migration (e.g. just copying over disks and XMLs), no qemu is involved and thus no vmstate matters.
/* perform these checks only when migrating to remote hosts */ if (remote) { nsnapshots = virDomainSnapshotObjListNum(vm->snapshots, NULL, 0);
Michal