* David Gibson (da...@gibson.dropbear.id.au) wrote:
> On Wed, Feb 25, 2015 at 04:51:46PM +0000, Dr. David Alan Gilbert (git) wrote:
> > From: "Dr. David Alan Gilbert" <dgilb...@redhat.com>
> >
> > Once postcopy is enabled (with migrate_set_capability), the migration
> > will still start on precopy mode. To cause a transition into postcopy
> > the:
> >
> > migrate_start_postcopy
> >
> > command must be issued. Postcopy will start sometime after this
> > (when it's next checked in the migration loop).
> >
> > Issuing the command before migration has started will error,
> > and issuing after it has finished is ignored.
> >
> > Signed-off-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> > Reviewed-by: Eric Blake <ebl...@redhat.com>
> > ---
> > hmp-commands.hx | 15 +++++++++++++++
> > hmp.c | 7 +++++++
> > hmp.h | 1 +
> > include/migration/migration.h | 3 +++
> > migration/migration.c | 22 ++++++++++++++++++++++
> > qapi-schema.json | 8 ++++++++
> > qmp-commands.hx | 19 +++++++++++++++++++
> > 7 files changed, 75 insertions(+)
> >
> > diff --git a/hmp-commands.hx b/hmp-commands.hx
> > index e37bc8b..03b8b78 100644
> > --- a/hmp-commands.hx
> > +++ b/hmp-commands.hx
> > @@ -985,6 +985,21 @@ Enable/Disable the usage of a capability
> > @var{capability} for migration.
> > ETEXI
> >
> > {
> > + .name = "migrate_start_postcopy",
> > + .args_type = "",
> > + .params = "",
> > + .help = "Switch migration to postcopy mode",
> > + .mhandler.cmd = hmp_migrate_start_postcopy,
> > + },
> > +
> > +STEXI
> > +@item migrate_start_postcopy
> > +@findex migrate_start_postcopy
> > +Switch in-progress migration to postcopy mode. Ignored after the end of
> > +migration (or once already in postcopy).
> > +ETEXI
> > +
> > + {
> > .name = "client_migrate_info",
> > .args_type =
> > "protocol:s,hostname:s,port:i?,tls-port:i?,cert-subject:s?",
> > .params = "protocol hostname port tls-port cert-subject",
> > diff --git a/hmp.c b/hmp.c
> > index b47f331..df9736c 100644
> > --- a/hmp.c
> > +++ b/hmp.c
> > @@ -1140,6 +1140,13 @@ void hmp_migrate_set_capability(Monitor *mon, const
> > QDict *qdict)
> > }
> > }
> >
> > +void hmp_migrate_start_postcopy(Monitor *mon, const QDict *qdict)
> > +{
> > + Error *err = NULL;
> > + qmp_migrate_start_postcopy(&err);
> > + hmp_handle_error(mon, &err);
> > +}
> > +
> > void hmp_set_password(Monitor *mon, const QDict *qdict)
> > {
> > const char *protocol = qdict_get_str(qdict, "protocol");
> > diff --git a/hmp.h b/hmp.h
> > index 4bb5dca..da1334f 100644
> > --- a/hmp.h
> > +++ b/hmp.h
> > @@ -64,6 +64,7 @@ void hmp_migrate_set_downtime(Monitor *mon, const QDict
> > *qdict);
> > void hmp_migrate_set_speed(Monitor *mon, const QDict *qdict);
> > void hmp_migrate_set_capability(Monitor *mon, const QDict *qdict);
> > void hmp_migrate_set_cache_size(Monitor *mon, const QDict *qdict);
> > +void hmp_migrate_start_postcopy(Monitor *mon, const QDict *qdict);
> > void hmp_set_password(Monitor *mon, const QDict *qdict);
> > void hmp_expire_password(Monitor *mon, const QDict *qdict);
> > void hmp_eject(Monitor *mon, const QDict *qdict);
> > diff --git a/include/migration/migration.h b/include/migration/migration.h
> > index e6a814a..293c83e 100644
> > --- a/include/migration/migration.h
> > +++ b/include/migration/migration.h
> > @@ -104,6 +104,9 @@ struct MigrationState
> > int64_t xbzrle_cache_size;
> > int64_t setup_time;
> > int64_t dirty_sync_count;
> > +
> > + /* Flag set once the migration has been asked to enter postcopy */
> > + bool start_postcopy;
> > };
> >
> > void process_incoming_migration(QEMUFile *f);
> > diff --git a/migration/migration.c b/migration/migration.c
> > index a4fc7d7..43ca656 100644
> > --- a/migration/migration.c
> > +++ b/migration/migration.c
> > @@ -372,6 +372,28 @@ void
> > qmp_migrate_set_capabilities(MigrationCapabilityStatusList *params,
> > }
> > }
> >
> > +void qmp_migrate_start_postcopy(Error **errp)
> > +{
> > + MigrationState *s = migrate_get_current();
> > +
> > + if (!migrate_postcopy_ram()) {
> > + error_setg(errp, "Enable postcopy with migration_set_capability
> > before"
> > + " the start of migration");
> > + return;
> > + }
> > +
> > + if (s->state == MIG_STATE_NONE) {
> > + error_setg(errp, "Postcopy must be started after migration has
> > been"
> > + " started");
> > + return;
> > + }
> > + /*
> > + * we don't error if migration has finished since that would be racy
> > + * with issuing this command.
> > + */
> > + atomic_set(&s->start_postcopy, true);
>
> Why atomic_set?
It's being read by the migration thread, this is happening in the main thread.
There's no strict ordering requirement or anything.
Dave
>
> > +}
> > +
> > /* shared migration helpers */
> >
> > static void migrate_set_state(MigrationState *s, int old_state, int
> > new_state)
> > diff --git a/qapi-schema.json b/qapi-schema.json
> > index a8af1cb..7ff61e9 100644
> > --- a/qapi-schema.json
> > +++ b/qapi-schema.json
> > @@ -542,6 +542,14 @@
> > { 'command': 'query-migrate-capabilities', 'returns':
> > ['MigrationCapabilityStatus']}
> >
> > ##
> > +# @migrate-start-postcopy
> > +#
> > +# Switch migration to postcopy mode
> > +#
> > +# Since: 2.3
> > +{ 'command': 'migrate-start-postcopy' }
> > +
> > +##
> > # @MouseInfo:
> > #
> > # Information about a mouse device.
> > diff --git a/qmp-commands.hx b/qmp-commands.hx
> > index a85d847..25d2208 100644
> > --- a/qmp-commands.hx
> > +++ b/qmp-commands.hx
> > @@ -685,6 +685,25 @@ Example:
> >
> > EQMP
> > {
> > + .name = "migrate-start-postcopy",
> > + .args_type = "",
> > + .mhandler.cmd_new = qmp_marshal_input_migrate_start_postcopy,
> > + },
> > +
> > +SQMP
> > +migrate-start-postcopy
> > +----------------------
> > +
> > +Switch an in-progress migration to postcopy mode. Ignored after the end of
> > +migration (or once already in postcopy).
> > +
> > +Example:
> > +-> { "execute": "migrate-start-postcopy" }
> > +<- { "return": {} }
> > +
> > +EQMP
> > +
> > + {
> > .name = "query-migrate-cache-size",
> > .args_type = "",
> > .mhandler.cmd_new = qmp_marshal_input_query_migrate_cache_size,
>
> --
> David Gibson | I'll have my music baroque, and my code
> david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_
> _other_
> | _way_ _around_!
> http://www.ozlabs.org/~dgibson
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
