From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57927) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YXOgc-0008EI-G3 for qemu-devel@nongnu.org; Mon, 16 Mar 2015 02:39:39 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YXOgV-0005ME-I0 for qemu-devel@nongnu.org; Mon, 16 Mar 2015 02:39:38 -0400 Received: from ozlabs.org ([103.22.144.67]:59302) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YXOgU-0005LW-UH for qemu-devel@nongnu.org; Mon, 16 Mar 2015 02:39:31 -0400 Date: Mon, 16 Mar 2015 17:23:55 +1100 From: David Gibson Message-ID: <20150316062355.GG5741@voom.redhat.com> References: <1424883128-9841-1-git-send-email-dgilbert@redhat.com> <1424883128-9841-24-git-send-email-dgilbert@redhat.com> <20150313012652.GB11973@voom.redhat.com> <20150313111905.GC2486@work-vm> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="5xSkJheCpeK0RUEJ" Content-Disposition: inline In-Reply-To: <20150313111905.GC2486@work-vm> Subject: Re: [Qemu-devel] [PATCH v5 23/45] migrate_start_postcopy: Command to trigger transition to postcopy List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert" Cc: aarcange@redhat.com, yamahata@private.email.ne.jp, quintela@redhat.com, qemu-devel@nongnu.org, amit.shah@redhat.com, pbonzini@redhat.com, yanghy@cn.fujitsu.com --5xSkJheCpeK0RUEJ Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Mar 13, 2015 at 11:19:06AM +0000, Dr. David Alan Gilbert wrote: > * David Gibson (david@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" > > >=20 > > > Once postcopy is enabled (with migrate_set_capability), the migration > > > will still start on precopy mode. To cause a transition into postcopy > > > the: > > >=20 > > > migrate_start_postcopy > > >=20 > > > command must be issued. Postcopy will start sometime after this > > > (when it's next checked in the migration loop). > > >=20 > > > Issuing the command before migration has started will error, > > > and issuing after it has finished is ignored. > > >=20 > > > Signed-off-by: Dr. David Alan Gilbert > > > Reviewed-by: Eric Blake > > > --- > > > 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(+) > > >=20 > > > 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{ca= pability} for migration. > > > ETEXI > > > =20 > > > { > > > + .name =3D "migrate_start_postcopy", > > > + .args_type =3D "", > > > + .params =3D "", > > > + .help =3D "Switch migration to postcopy mode", > > > + .mhandler.cmd =3D 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 =3D "client_migrate_info", > > > .args_type =3D "protocol:s,hostname:s,port:i?,tls-port:i?,c= ert-subject:s?", > > > .params =3D "protocol hostname port tls-port cert-subjec= t", > > > 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) > > > } > > > } > > > =20 > > > +void hmp_migrate_start_postcopy(Monitor *mon, const QDict *qdict) > > > +{ > > > + Error *err =3D NULL; > > > + qmp_migrate_start_postcopy(&err); > > > + hmp_handle_error(mon, &err); > > > +} > > > + > > > void hmp_set_password(Monitor *mon, const QDict *qdict) > > > { > > > const char *protocol =3D 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 Q= Dict *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/migrat= ion.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; > > > }; > > > =20 > > > 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(MigrationCapab= ilityStatusList *params, > > > } > > > } > > > =20 > > > +void qmp_migrate_start_postcopy(Error **errp) > > > +{ > > > + MigrationState *s =3D migrate_get_current(); > > > + > > > + if (!migrate_postcopy_ram()) { > > > + error_setg(errp, "Enable postcopy with migration_set_capabil= ity before" > > > + " the start of migration"); > > > + return; > > > + } > > > + > > > + if (s->state =3D=3D MIG_STATE_NONE) { > > > + error_setg(errp, "Postcopy must be started after migration h= as 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); > >=20 > > Why atomic_set? >=20 > It's being read by the migration thread, this is happening in the main th= read. >=20 > There's no strict ordering requirement or anything. I don't think you need an atomic then. AFAIK an atomic_set() in isolation without some sort of atomic on the other side is pretty much meaningless. --=20 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 --5xSkJheCpeK0RUEJ Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJVBnb7AAoJEGw4ysog2bOSKAkQAKp3oROpxqGXMc4idwXI4ZfF HFtesSKsfTdevv+VX0bkpGiHCnHfJKkMm3QpMb4Tdks+EQX3RHzBNG4HDfmsIHtS ajx8vhtIgzoI1VOfc6CaKyqyn7LTbJUUWdY03P/VKkfXB5RaWiYOg1PZU2RR4gKj pEm89zMm/O4TKF9O1qAGBlcAaAs0eufG+kwYeX/8vp3nvpuaWfJ3Vg/P8GgrzLVX zHP+AiNZPkMxvVsUMCIMbVaMccZ6Z4ZNhx5ZnILfqUJZ1JD4AwtNgIOG8BzOrkze hzua0/hxUDJLp/UEiIMsbgzOoxAC81X5OBUVk8svf0S5NI16i47PoMQDWO74B868 J78ece5f0PE+dD+3w+4aa26K9i2+/BMOGS0yFqi65uUI4wco7pyeC/bx1gWErkdN cvaKibrmE6px29EkX10o/esSiWZL/QJveO8NfzgiDRtrunX4mJn1HK4PRrZdHRzk Ko98Gcx665y0XZZ8oEf+K0tGFmhjW9eveoqbGz5/+TdTJj7LYOtIn16RpQse+5xD 0l0LuUE8dIMZdFHiutLH0YL+0owzKDDWJiqUv4APugY2yyOf30WPUBYES/ubcuuV OEW/xWQOC4qG3EjNJ9xs+cKKKf/OMxVn5h0nhwBSXZfw0wul4/v2odAx0oOmJwVR jwa+SJjiCED+P7fOq5Ti =gkKI -----END PGP SIGNATURE----- --5xSkJheCpeK0RUEJ--