On Mon, 23 May 2016 22:49:46 +0530 Amit Shah <amit.s...@redhat.com> wrote:
> From: Greg Kurz <gk...@linux.vnet.ibm.com> > > QEMU has currently two ways to prevent migration to occur: > - migration blocker when it depends on runtime state > - VMStateDescription.unmigratable when migration is not supported at all > > This patch gathers all the logic into a single function to be called from > both the savevm and the migrate paths. > > This fixes a bug with 9p, at least, where savevm would succeed and the > following would happen in the guest after loadvm: > > $ ls /host > ls: cannot access /host: Protocol error > > With this patch: > > (qemu) savevm foo > Migration is disabled when VirtFS export path '/' is mounted in the guest > using mount_tag 'host' > > Signed-off-by: Greg Kurz <gk...@linux.vnet.ibm.com> > Reviewed-by: Paolo Bonzini <pbonz...@redhat.com> > Message-Id: <146239057139.11271.9011797645454781543.st...@bahia.huguette.org> > > [Update subject according to Paolo's suggestion - Amit] > > Signed-off-by: Amit Shah <amit.s...@redhat.com> > --- FWIW this patch also fixes the issue in QEMU 2.5. > include/migration/migration.h | 1 + > migration/migration.c | 21 +++++++++++++++------rtl8139 > migration/savevm.c | 2 +- > 3 files changed, 17 insertions(+), 7 deletions(-) > > diff --git a/include/migration/migration.h b/include/migration/migration.h > index ac2c12c..9e36a97 100644 > --- a/include/migration/migration.h > +++ b/include/migration/migration.h > @@ -210,6 +210,7 @@ int migrate_fd_close(MigrationState *s); > void add_migration_state_change_notifier(Notifier *notify); > void remove_migration_state_change_notifier(Notifier *notify); > MigrationState *migrate_init(const MigrationParams *params); > +bool migration_is_blocked(Error **errp); > bool migration_in_setup(MigrationState *); > bool migration_has_finished(MigrationState *); > bool migration_has_failed(MigrationState *); > diff --git a/migration/migration.c b/migration/migration.c > index 12dbf5b..721d010 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -992,6 +992,20 @@ void qmp_migrate_incoming(const char *uri, Error **errp) > once = false; > } > > +bool migration_is_blocked(Error **errp) > +{ > + if (qemu_savevm_state_blocked(errp)) { > + return true; > + } > + > + if (migration_blockers) { > + *errp = error_copy(migration_blockers->data); > + return true; > + } > + > + return false; > +} > + > void qmp_migrate(const char *uri, bool has_blk, bool blk, > bool has_inc, bool inc, bool has_detach, bool detach, > Error **errp) > @@ -1014,12 +1028,7 @@ void qmp_migrate(const char *uri, bool has_blk, bool > blk, > return; > } > > - if (qemu_savevm_state_blocked(errp)) { > - return; > - } > - > - if (migration_blockers) { > - *errp = error_copy(migration_blockers->data); > + if (migration_is_blocked(errp)) { > return; > } > > diff --git a/migration/savevm.c b/migration/savevm.c > index 8546fdf..f8450fd 100644 > --- a/migration/savevm.c > +++ b/migration/savevm.c > @@ -1170,7 +1170,7 @@ static int qemu_savevm_state(QEMUFile *f, Error **errp) > MigrationState *ms = migrate_init(¶ms); > ms->to_dst_file = f; > > - if (qemu_savevm_state_blocked(errp)) { > + if (migration_is_blocked(errp)) { > return -EINVAL; > } >