> -----Original Message-----
> From: Vladimir Sementsov-Ogievskiy <vsement...@yandex-team.ru>
> Sent: Thursday, May 4, 2023 4:23 PM
> To: Zhang, Chen <chen.zh...@intel.com>; qemu-devel@nongnu.org
> Cc: lukasstra...@web.de; quint...@redhat.com; Peter Xu
> <pet...@redhat.com>; Leonardo Bras <leob...@redhat.com>
> Subject: Re: [PATCH v4 09/10] migration: disallow change capabilities in COLO
> state
>
> On 04.05.23 11:09, Zhang, Chen wrote:
> >
> >
> >> -----Original Message-----
> >> From: Vladimir Sementsov-Ogievskiy <vsement...@yandex-team.ru>
> >> Sent: Saturday, April 29, 2023 3:49 AM
> >> To: qemu-devel@nongnu.org
> >> Cc: lukasstra...@web.de; quint...@redhat.com; Zhang, Chen
> >> <chen.zh...@intel.com>; vsement...@yandex-team.ru; Peter Xu
> >> <pet...@redhat.com>; Leonardo Bras <leob...@redhat.com>
> >> Subject: [PATCH v4 09/10] migration: disallow change capabilities in
> >> COLO state
> >>
> >> COLO is not listed as running state in migrate_is_running(), so, it's
> >> theoretically possible to disable colo capability in COLO state and
> >> the unexpected error in migration_iteration_finish() is reachable.
> >>
> >> Let's disallow that in qmp_migrate_set_capabilities. Than the error
> >> becomes absolutely unreachable: we can get into COLO state only with
> >> enabled capability and can't disable it while we are in COLO state.
> >> So substitute the error by simple assertion.
> >>
> >> Signed-off-by: Vladimir Sementsov-Ogievskiy
> >> <vsement...@yandex-team.ru>
> >> ---
> >> migration/migration.c | 5 +----
> >> migration/options.c | 2 +-
> >> 2 files changed, 2 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/migration/migration.c b/migration/migration.c index
> >> 0d912ee0d7..8c5bbf3e94 100644
> >> --- a/migration/migration.c
> >> +++ b/migration/migration.c
> >> @@ -2751,10 +2751,7 @@ static void
> >> migration_iteration_finish(MigrationState *s)
> >> runstate_set(RUN_STATE_POSTMIGRATE);
> >> break;
> >> case MIGRATION_STATUS_COLO:
> >> - if (!migrate_colo()) {
> >> - error_report("%s: critical error: calling COLO code without "
> >> - "COLO enabled", __func__);
> >> - }
> >> + assert(migrate_colo());
> >> migrate_start_colo_process(s);
> >> s->vm_was_running = true;
> >> /* Fallthrough */
> >> diff --git a/migration/options.c b/migration/options.c index
> >> 865a0214d8..f461d02eeb 100644
> >> --- a/migration/options.c
> >> +++ b/migration/options.c
> >> @@ -598,7 +598,7 @@ void
> >> qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
> >> MigrationCapabilityStatusList *cap;
> >> bool new_caps[MIGRATION_CAPABILITY__MAX];
> >>
> >> - if (migration_is_running(s->state)) {
> >> + if (migration_is_running(s->state) || migration_in_colo_state())
> >> + {
> >
> > Make the "MIGRATION_STATUS_COLO" into the " migration_is_running()"
> is a better way?
>
> I wasn't sure that that's correct.. migration_is_running() is used in several
> places, to do so, I'd have to analyze them all.
Actually, when running in the "MIGRATION_STATUS_COLO" means QEMU can not
do a normal migration at the same time.
Juan have any comments here?
Thanks
Chen
>
> > Like the "migration_is_setup_ot_active()".
> >
> > Thanks
> > Chen
> >
> >> error_setg(errp, QERR_MIGRATION_ACTIVE);
> >> return;
> >> }
> >> --
> >> 2.34.1
> >
>
> --
> Best regards,
> Vladimir
