From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33636) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1e52HH-0004za-98 for qemu-devel@nongnu.org; Thu, 19 Oct 2017 00:17:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1e52HC-000437-9P for qemu-devel@nongnu.org; Thu, 19 Oct 2017 00:17:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:52970) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1e52HC-00041Z-0V for qemu-devel@nongnu.org; Thu, 19 Oct 2017 00:17:46 -0400 Date: Thu, 19 Oct 2017 12:17:37 +0800 From: Peter Xu Message-ID: <20171019041737.GS4166@pxdev.xzpeter.org> References: <20171018174013.22709-1-dgilbert@redhat.com> <20171018174013.22709-2-dgilbert@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20171018174013.22709-2-dgilbert@redhat.com> Subject: Re: [Qemu-devel] [PATCH v3 1/7] migration: Add 'pause-before-switchover' capability List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Dr. David Alan Gilbert (git)" Cc: qemu-devel@nongnu.org, kwolf@redhat.com, jdenemar@redhat.com, wangjie88@huawei.com, quintela@redhat.com, mreitz@redhat.com, berrange@redhat.com, eblake@redhat.com, fuweiwei2@huawei.com On Wed, Oct 18, 2017 at 06:40:07PM +0100, Dr. David Alan Gilbert (git) wrote: > From: "Dr. David Alan Gilbert" > > When 'pause-before-switchover' is enabled, the outgoing migration > will pause before invalidating the block devices and serializing > the device state. > At this point the management layer gets the chance to clean up any > device jobs or other device users before the migration completes. > > Signed-off-by: Dr. David Alan Gilbert > --- > migration/migration.c | 10 ++++++++++ > migration/migration.h | 1 + > qapi/migration.json | 5 ++++- > 3 files changed, 15 insertions(+), 1 deletion(-) > > diff --git a/migration/migration.c b/migration/migration.c > index 98429dc843..fba3342368 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -1521,6 +1521,16 @@ bool migrate_use_multifd(void) > return s->enabled_capabilities[MIGRATION_CAPABILITY_X_MULTIFD]; > } > > +bool migrate_pause_before_switchover(void) > +{ > + MigrationState *s; > + > + s = migrate_get_current(); > + > + return s->enabled_capabilities[ > + MIGRATION_CAPABILITY_PAUSE_BEFORE_SWITCHOVER]; > +} > + > int migrate_multifd_channels(void) > { > MigrationState *s; > diff --git a/migration/migration.h b/migration/migration.h > index b83cceadc4..969866303e 100644 > --- a/migration/migration.h > +++ b/migration/migration.h > @@ -177,6 +177,7 @@ bool migrate_zero_blocks(void); > > bool migrate_auto_converge(void); > bool migrate_use_multifd(void); > +bool migrate_pause_before_switchover(void); > int migrate_multifd_channels(void); > int migrate_multifd_page_count(void); > > diff --git a/qapi/migration.json b/qapi/migration.json > index f8b365e3f5..4960231ba2 100644 > --- a/qapi/migration.json > +++ b/qapi/migration.json > @@ -341,6 +341,9 @@ > # @return-path: If enabled, migration will use the return path even > # for precopy. (since 2.10) > # > +# @pause-before-switchover: Pause outgoing migration before serialising device > +# state and before disabling block IO (since 2.11) Nit: Not sure whether it's good to avoid naming "disabling block IO", since after all this pre-switch state can be used to do other things as well in the future. Reviewed-by: Peter Xu > +# > # @x-multifd: Use more than one fd for migration (since 2.11) > # > # Since: 1.2 > @@ -348,7 +351,7 @@ > { 'enum': 'MigrationCapability', > 'data': ['xbzrle', 'rdma-pin-all', 'auto-converge', 'zero-blocks', > 'compress', 'events', 'postcopy-ram', 'x-colo', 'release-ram', > - 'block', 'return-path', 'x-multifd' ] } > + 'block', 'return-path', 'pause-before-switchover', 'x-multifd' ] } > > ## > # @MigrationCapabilityStatus: > -- > 2.13.6 > -- Peter Xu