migration: simplify blockers

Modify migrate_add_blocker and migrate_del_blocker to take an Error **
reason.  This allows migration to own the Error object, so that if
an error occurs in migrate_add_blocker, migration code can free the Error
and clear the client handle, simplifying client code.  It also simplifies
the migrate_del_blocker call site.

In addition, this is a pre-requisite for a proposed future patch that would
add a mode argument to migration requests to support live update, and
maintain a list of blockers for each mode.  A blocker may apply to a single
mode or to multiple modes, and passing Error** will allow one Error object
to be registered for multiple modes.

No functional change.

Signed-off-by: Steve Sistare <steven.sistare@oracle.com>
Tested-by: Michael Galaxy <mgalaxy@akamai.com>
Reviewed-by: Michael Galaxy <mgalaxy@akamai.com>
Reviewed-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Message-ID: <1697634216-84215-1-git-send-email-steven.sistare@oracle.com>
This commit is contained in:
Steve Sistare 2023-10-18 06:03:36 -07:00 committed by Juan Quintela
parent 04131e0009
commit c8a7fc5179
33 changed files with 92 additions and 150 deletions

View file

@ -1761,7 +1761,7 @@ static void spapr_machine_reset(MachineState *machine, ShutdownCause reason)
/* Signal all vCPUs waiting on this condition */
qemu_cond_broadcast(&spapr->fwnmi_machine_check_interlock_cond);
migrate_del_blocker(spapr->fwnmi_migration_blocker);
migrate_del_blocker(&spapr->fwnmi_migration_blocker);
}
static void spapr_create_nvram(SpaprMachineState *spapr)
@ -2937,13 +2937,6 @@ static void spapr_machine_init(MachineState *machine)
spapr_create_lmb_dr_connectors(spapr);
}
if (spapr_get_cap(spapr, SPAPR_CAP_FWNMI) == SPAPR_CAP_ON) {
/* Create the error string for live migration blocker */
error_setg(&spapr->fwnmi_migration_blocker,
"A machine check is being handled during migration. The handler"
"may run and log hardware error on the destination");
}
if (mc->nvdimm_supported) {
spapr_create_nvdimm_dr_connectors(spapr);
}