From 8958338b10abcb346b54a8038a491fda2db1c853 Mon Sep 17 00:00:00 2001 From: Zhimin Feng Date: Tue, 14 Jan 2020 17:43:09 +0800 Subject: [PATCH] migration: Maybe VM is paused when migration is cancelled If the migration is cancelled when it is in the completion phase, the migration state is set to MIGRATION_STATUS_CANCELLING. The VM maybe wait for the 'pause_sem' semaphore in migration_maybe_pause function, so that VM always is paused. Reported-by: Euler Robot Signed-off-by: Zhimin Feng Reviewed-by: Juan Quintela Signed-off-by: Juan Quintela --- migration/migration.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 3a21a4686c..1ca6be2323 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -2797,14 +2797,22 @@ static int migration_maybe_pause(MigrationState *s, /* This block intentionally left blank */ } - qemu_mutex_unlock_iothread(); - migrate_set_state(&s->state, *current_active_state, - MIGRATION_STATUS_PRE_SWITCHOVER); - qemu_sem_wait(&s->pause_sem); - migrate_set_state(&s->state, MIGRATION_STATUS_PRE_SWITCHOVER, - new_state); - *current_active_state = new_state; - qemu_mutex_lock_iothread(); + /* + * If the migration is cancelled when it is in the completion phase, + * the migration state is set to MIGRATION_STATUS_CANCELLING. + * So we don't need to wait a semaphore, otherwise we would always + * wait for the 'pause_sem' semaphore. + */ + if (s->state != MIGRATION_STATUS_CANCELLING) { + qemu_mutex_unlock_iothread(); + migrate_set_state(&s->state, *current_active_state, + MIGRATION_STATUS_PRE_SWITCHOVER); + qemu_sem_wait(&s->pause_sem); + migrate_set_state(&s->state, MIGRATION_STATUS_PRE_SWITCHOVER, + new_state); + *current_active_state = new_state; + qemu_mutex_lock_iothread(); + } return s->state == new_state ? 0 : -EINVAL; }