From 4c11e06222ca5a88f48f2d47adc3a7da306bb345 Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Tue, 29 Jun 2021 14:13:55 -0400 Subject: [PATCH 01/39] migration: Move yank outside qemu_start_incoming_migration() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Leonardo Brás RH-MergeRequest: 25: migration: Move yank outside qemu_start_incoming_migration() RH-Commit: [1/2] e5694b0ae9a55f6b147c336e86fce6f4f2163db6 (LeoBras/centos-qemu-kvm) RH-Bugzilla: 1974683 RH-Acked-by: Miroslav Rezanina RH-Acked-by: Peter Xu > Starting from commit b5eea99ec2f5c, qmp_migrate_recover() calls unregister before calling qemu_start_incoming_migration(). I believe it wanted to mitigate the next call to yank_register_instance(), but I think that's wrong. Firstly, if during recover, we should keep the yank instance there, not "quickly removing and adding it back". Meanwhile, calling qmp_migrate_recover() twice with b5eea99ec2f5c will directly crash the dest qemu (right now it can't; but it'll start to work right after the next patch) because the 1st call of qmp_migrate_recover() will unregister permanently when the channel failed to establish, then the 2nd call of qmp_migrate_recover() crashes at yank_unregister_instance(). This patch fixes it by moving yank ops out of qemu_start_incoming_migration() into qmp_migrate_incoming. For qmp_migrate_recover(), drop the unregister of yank instance too since we keep it there during the recovery phase. Signed-off-by: Peter Xu Reviewed-by: Dr. David Alan Gilbert Message-Id: <20210629181356.217312-2-peterx@redhat.com> Signed-off-by: Dr. David Alan Gilbert (cherry picked from commit cc48c587d25ff5dd7dddb4e5072de9ca8464c832) Fixes: b5eea99e ("migration: Add yank feature", 2021-01-13) Signed-off-by: Leonardo Bras Signed-off-by: Miroslav Rezanina --- migration/migration.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 4afc6069b6..f077640df2 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -454,10 +454,6 @@ static void qemu_start_incoming_migration(const char *uri, Error **errp) { const char *p = NULL; - if (!yank_register_instance(MIGRATION_YANK_INSTANCE, errp)) { - return; - } - qapi_event_send_migration(MIGRATION_STATUS_SETUP); if (strstart(uri, "tcp:", &p) || strstart(uri, "unix:", NULL) || @@ -472,7 +468,6 @@ static void qemu_start_incoming_migration(const char *uri, Error **errp) } else if (strstart(uri, "fd:", &p)) { fd_start_incoming_migration(p, errp); } else { - yank_unregister_instance(MIGRATION_YANK_INSTANCE); error_setg(errp, "unknown migration protocol: %s", uri); } } @@ -2095,9 +2090,14 @@ void qmp_migrate_incoming(const char *uri, Error **errp) return; } + if (!yank_register_instance(MIGRATION_YANK_INSTANCE, errp)) { + return; + } + qemu_start_incoming_migration(uri, &local_err); if (local_err) { + yank_unregister_instance(MIGRATION_YANK_INSTANCE); error_propagate(errp, local_err); return; } @@ -2126,7 +2126,6 @@ void qmp_migrate_recover(const char *uri, Error **errp) * only re-setup the migration stream and poke existing migration * to continue using that newly established channel. */ - yank_unregister_instance(MIGRATION_YANK_INSTANCE); qemu_start_incoming_migration(uri, errp); } -- 2.27.0