From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:53492) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dFjYE-0007yL-A8 for qemu-devel@nongnu.org; Tue, 30 May 2017 11:59:19 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dFjYB-0005Yb-28 for qemu-devel@nongnu.org; Tue, 30 May 2017 11:59:18 -0400 Received: from mx1.redhat.com ([209.132.183.28]:59718) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1dFjYA-0005YN-Pe for qemu-devel@nongnu.org; Tue, 30 May 2017 11:59:14 -0400 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AB18A61D0F for ; Tue, 30 May 2017 15:59:13 +0000 (UTC) From: Juan Quintela In-Reply-To: <1495176212-14446-7-git-send-email-peterx@redhat.com> (Peter Xu's message of "Fri, 19 May 2017 14:43:32 +0800") References: <1495176212-14446-1-git-send-email-peterx@redhat.com> <1495176212-14446-7-git-send-email-peterx@redhat.com> Reply-To: quintela@redhat.com Date: Tue, 30 May 2017 17:59:10 +0200 Message-ID: <87shjme3ox.fsf@secure.mitica> MIME-Version: 1.0 Content-Type: text/plain Subject: Re: [Qemu-devel] [PATCH RFC 6/6] migration: enable return path for precopy List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Peter Xu Cc: qemu-devel@nongnu.org, "Dr . David Alan Gilbert" Peter Xu wrote: > Let this be a flag, default to on. Turn it off for <=2.9 versions. > > After this patch, return path will be on even for pre-copy migration as > long as the transport support, e.g., for socket typed transport > including "tcp|udp|unix" typed. > > This will naturally fix the bug mentioned below, when destination failed > on migration but source assumed it was successful - since now even for > precopy, source will wait for destination's MIG_RP_MSG_SHUT signal, > which will carry the final migration status of destination. Then, when > destination failed at any point of migration, source will know it, and > it'll resume the VM instead of a data lost. > > Bug: https://bugzilla.redhat.com/show_bug.cgi?id=1439147 > Signed-off-by: Peter Xu > --- > include/hw/compat.h | 4 ++++ > include/migration/migration.h | 3 +++ > migration/migration.c | 15 ++++++++++++++- > 3 files changed, 21 insertions(+), 1 deletion(-) > > diff --git a/include/hw/compat.h b/include/hw/compat.h > index 55b1765..049457b 100644 > --- a/include/hw/compat.h > +++ b/include/hw/compat.h > @@ -6,6 +6,10 @@ > .driver = "pci-bridge",\ > .property = "shpc",\ > .value = "off",\ > + },{\ > + .driver = "migration",\ > + .property = "return-path",\ > + .value = "off",\ > }, > > #define HW_COMPAT_2_8 \ > diff --git a/include/migration/migration.h b/include/migration/migration.h > index 70710de..e44119c 100644 > --- a/include/migration/migration.h > +++ b/include/migration/migration.h > @@ -169,6 +169,9 @@ typedef struct MigrationState { > int64_t colo_checkpoint_time; > QEMUTimer *colo_delay_timer; > > + /* Whether to try to enable return-path even for pre-copy */ > + bool enable_return_path; > + > /* The last error that occurred */ > Error *error; > } MigrationState ; > diff --git a/migration/migration.c b/migration/migration.c > index 6df3483..16a856a 100644 > --- a/migration/migration.c > +++ b/migration/migration.c > @@ -2046,7 +2046,7 @@ static void *migration_thread(void *opaque) > static bool migrate_return_path_create(MigrationState *s) > { > /* Whether we should enable return path */ > - bool enable_return_path = false; > + bool enable_return_path = s->enable_return_path; As you can see on my suggestion for this piece of code, just add the ()s->enable_return_path &&) to the right place on the call? Thanks, Juan.