[libvirt] [PATCH] qemu: Properly rename persistent def after migration

[Jiri Denemark]

On Tue, May 05, 2015 at 08:50:10 +0200, Jiri Denemark wrote:
> On Tue, May 05, 2015 at 08:30:30 +0200, Martin Kletzander wrote:
> > On Mon, May 04, 2015 at 11:02:18PM +0200, Jiri Denemark wrote:
> > >When migrating a domain while changing its name and using
> > >VIR_MIGRATE_PERSIST_DEST flag, libvirt would fail to properly change the
> > >name in the persistent definition. The inconsistency results in weird
> > >behavior when dumping domain XML, destroying the domain, restarting
> > >libvirtd and likely in several other situations.
> > >
> > >Since the new name is already stored in vm->def->name, we just need to
> > >make sure the persistent definition uses this new name too.
> > >
> > >https://bugzilla.redhat.com/show_bug.cgi?id=1076354
> > >
> > >Signed-off-by: Jiri Denemark <jdenemar at redhat.com>
> > >---
> > > src/qemu/qemu_migration.c | 8 ++++++++
> > > 1 file changed, 8 insertions(+)
> > >
> > >diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c
> > >index 20c2193..c1af704 100644
> > >--- a/src/qemu/qemu_migration.c
> > >+++ b/src/qemu/qemu_migration.c
> > >@@ -1392,6 +1392,14 @@ qemuMigrationEatCookie(virQEMUDriverPtr driver,
> > >                                        flags) < 0)
> > >         goto error;
> > >
> > >+    if (flags & QEMU_MIGRATION_COOKIE_PERSISTENT &&
> > 
> > Shouldn't you rather use mig->flags here?
> 
> Yeah, perhaps, after fixing the code to properly update mig->flags when
> persistent definition is parsed from the cookie :-)

After looking at the code once more, I'd rather avoid changing this. The
mig object created by qemuMigrationEatCookie is then reused by
qemuMigrationBakeCookie. Thus, if we changed the XML cookie parser to
set QEMU_MIGRATION_COOKIE_PERSISTENT in mig->flags when it parses the
persistent definition, it would then be also formated into the outgoing
cookie. This is all weired but I think using just flags is safer than
touching the way cookies are processed.

Jirka