From 58d47d795b91beb1f87929fb07d9f1b4af79cb14 Mon Sep 17 00:00:00 2001 From: Peter Xu Date: Wed, 22 Sep 2021 12:20:08 -0400 Subject: [PATCH 2/6] migration: Add migrate_add_blocker_internal() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit RH-Author: Peter Xu RH-MergeRequest: 51: dump-guest-memory: Add blocker for migration RH-Commit: [2/3] 44cf3879ee66cc9974dd3d8a5f9a0d4f762b7c01 (peterx/qemu-kvm) RH-Bugzilla: 1996609 RH-Acked-by: Dr. David Alan Gilbert RH-Acked-by: quintela1 RH-Acked-by: Laszlo Ersek An internal version that removes -only-migratable implications. It can be used for temporary migration blockers like dump-guest-memory. Reviewed-by: Marc-André Lureau Reviewed-by: Juan Quintela Signed-off-by: Peter Xu Signed-off-by: Juan Quintela (cherry picked from commit 60fd680193119e7e4d50eccff7b55a0aadc934ab) Signed-off-by: Peter Xu --- include/migration/blocker.h | 16 ++++++++++++++++ migration/migration.c | 21 +++++++++++++-------- 2 files changed, 29 insertions(+), 8 deletions(-) diff --git a/include/migration/blocker.h b/include/migration/blocker.h index acd27018e9..9cebe2ba06 100644 --- a/include/migration/blocker.h +++ b/include/migration/blocker.h @@ -25,6 +25,22 @@ */ int migrate_add_blocker(Error *reason, Error **errp); +/** + * @migrate_add_blocker_internal - prevent migration from proceeding without + * only-migrate implications + * + * @reason - an error to be returned whenever migration is attempted + * + * @errp - [out] The reason (if any) we cannot block migration right now. + * + * @returns - 0 on success, -EBUSY on failure, with errp set. + * + * Some of the migration blockers can be temporary (e.g., for a few seconds), + * so it shouldn't need to conflict with "-only-migratable". For those cases, + * we can call this function rather than @migrate_add_blocker(). + */ +int migrate_add_blocker_internal(Error *reason, Error **errp); + /** * @migrate_del_blocker - remove a blocking error from migration * diff --git a/migration/migration.c b/migration/migration.c index f476e2101e..2aaf2fd449 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -2053,15 +2053,8 @@ void migrate_init(MigrationState *s) s->threshold_size = 0; } -int migrate_add_blocker(Error *reason, Error **errp) +int migrate_add_blocker_internal(Error *reason, Error **errp) { - if (only_migratable) { - error_propagate_prepend(errp, error_copy(reason), - "disallowing migration blocker " - "(--only-migratable) for: "); - return -EACCES; - } - /* Snapshots are similar to migrations, so check RUN_STATE_SAVE_VM too. */ if (runstate_check(RUN_STATE_SAVE_VM) || !migration_is_idle()) { error_propagate_prepend(errp, error_copy(reason), @@ -2074,6 +2067,18 @@ int migrate_add_blocker(Error *reason, Error **errp) return 0; } +int migrate_add_blocker(Error *reason, Error **errp) +{ + if (only_migratable) { + error_propagate_prepend(errp, error_copy(reason), + "disallowing migration blocker " + "(--only-migratable) for: "); + return -EACCES; + } + + return migrate_add_blocker_internal(reason, errp); +} + void migrate_del_blocker(Error *reason) { migration_blockers = g_slist_remove(migration_blockers, reason); -- 2.27.0