From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53920) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1elzA3-0008IV-BC for qemu-devel@nongnu.org; Wed, 14 Feb 2018 10:39:58 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1elzA0-00075l-96 for qemu-devel@nongnu.org; Wed, 14 Feb 2018 10:39:55 -0500 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:37566 helo=mx1.redhat.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1elz9z-00074Z-VP for qemu-devel@nongnu.org; Wed, 14 Feb 2018 10:39:52 -0500 From: "Dr. David Alan Gilbert (git)" Date: Wed, 14 Feb 2018 15:39:30 +0000 Message-Id: <20180214153938.5410-3-dgilbert@redhat.com> In-Reply-To: <20180214153938.5410-1-dgilbert@redhat.com> References: <20180214153938.5410-1-dgilbert@redhat.com> Subject: [Qemu-devel] [PULL 02/10] migration: improve documentation of postcopy-ram List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, quintela@redhat.com, peterx@redhat.com, groug@kaod.org, ross.lagerwall@citrix.com From: Greg Kurz This capability must have the same value on both source and destination, otherwise migration fails (commit 875fcd013ab6 "migration: incoming postcopy advise sanity checks"). Let's write it down in various places where postcopy-ram is documented. Signed-off-by: Greg Kurz Message-Id: <151801810352.29167.4832480228518630626.stgit@bahia.lan> Signed-off-by: Dr. David Alan Gilbert Reviewed-by: Eric Blake Reviewed-by: Dr. David Alan Gilbert --- docs/devel/migration.rst | 4 ++-- hmp-commands.hx | 3 ++- qapi/migration.json | 10 ++++++---- 3 files changed, 10 insertions(+), 7 deletions(-) diff --git a/docs/devel/migration.rst b/docs/devel/migration.rst index bf97080dac..9d1b7657f0 100644 --- a/docs/devel/migration.rst +++ b/docs/devel/migration.rst @@ -387,8 +387,8 @@ doesn't finish in a given time the switch is made to postcopy. Enabling postcopy ----------------- -To enable postcopy, issue this command on the monitor prior to the -start of migration: +To enable postcopy, issue this command on the monitor (both source and +destination) prior to the start of migration: ``migrate_set_capability postcopy-ram on`` diff --git a/hmp-commands.hx b/hmp-commands.hx index 15620c94d3..d26eb4119b 100644 --- a/hmp-commands.hx +++ b/hmp-commands.hx @@ -1041,7 +1041,8 @@ ETEXI .params = "", .help = "Followup to a migration command to switch the migration" " to postcopy mode. The postcopy-ram capability must " - "be set before the original migration command.", + "be set on both source and destination before the " + "original migration command .", .cmd = hmp_migrate_start_postcopy, }, diff --git a/qapi/migration.json b/qapi/migration.json index 4cd3d13158..7f465a1902 100644 --- a/qapi/migration.json +++ b/qapi/migration.json @@ -327,8 +327,10 @@ # to speed up convergence of RAM migration. (since 1.6) # # @postcopy-ram: Start executing on the migration target before all of RAM has -# been migrated, pulling the remaining pages along as needed. NOTE: If -# the migration fails during postcopy the VM will fail. (since 2.6) +# been migrated, pulling the remaining pages along as needed. The +# capacity must have the same setting on both source and target +# or migration will not even start. NOTE: If the migration fails during +# postcopy the VM will fail. (since 2.6) # # @x-colo: If enabled, migration will never end, and the state of the VM on the # primary side will be migrated continuously to the VM on secondary @@ -742,8 +744,8 @@ # @migrate-start-postcopy: # # Followup to a migration command to switch the migration to postcopy mode. -# The postcopy-ram capability must be set before the original migration -# command. +# The postcopy-ram capability must be set on both source and destination +# before the original migration command. # # Since: 2.5 # -- 2.14.3