From b4e9ddccd1a64239c07d7229afd7e00eed5afcd8 Mon Sep 17 00:00:00 2001 From: Steve Sistare Date: Wed, 3 Jan 2024 12:05:35 -0800 Subject: [PATCH] migration: preserve suspended runstate A guest that is migrated in the suspended state automaticaly wakes and continues execution. This is wrong; the guest should end migration in the same state it started. The root cause is that the outgoing migration code automatically wakes the guest, then saves the RUNNING runstate in global_state_store(), hence the incoming migration code thinks the guest is running and continues the guest if autostart is true. On the outgoing side, delete the call to qemu_system_wakeup_request(). Now that vm_stop completely stops a vm in the suspended state (from the preceding patches), the existing call to vm_stop_force_state is sufficient to correctly migrate all vmstate. On the incoming side, call vm_start if the pre-migration state was running or suspended. For the latter, vm_start correctly restores the suspended state, and a future system_wakeup monitor request will cause the vm to resume running. Signed-off-by: Steve Sistare Reviewed-by: Peter Xu Link: https://lore.kernel.org/r/1704312341-66640-7-git-send-email-steven.sistare@oracle.com Signed-off-by: Peter Xu --- migration/migration.c | 8 +++----- 1 file changed, 3 insertions(+), 5 deletions(-) diff --git a/migration/migration.c b/migration/migration.c index 3ce04b2aaf..8124811045 100644 --- a/migration/migration.c +++ b/migration/migration.c @@ -604,7 +604,7 @@ static void process_incoming_migration_bh(void *opaque) */ if (!migrate_late_block_activate() || (autostart && (!global_state_received() || - global_state_get_runstate() == RUN_STATE_RUNNING))) { + runstate_is_live(global_state_get_runstate())))) { /* Make sure all file formats throw away their mutable metadata. * If we get an error here, just don't restart the VM yet. */ bdrv_activate_all(&local_err); @@ -628,7 +628,7 @@ static void process_incoming_migration_bh(void *opaque) dirty_bitmap_mig_before_vm_start(); if (!global_state_received() || - global_state_get_runstate() == RUN_STATE_RUNNING) { + runstate_is_live(global_state_get_runstate())) { if (autostart) { vm_start(); } else { @@ -2416,7 +2416,6 @@ static int postcopy_start(MigrationState *ms, Error **errp) migration_downtime_start(ms); - qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL); global_state_store(); ret = migration_stop_vm(RUN_STATE_FINISH_MIGRATE); if (ret < 0) { @@ -2615,7 +2614,6 @@ static int migration_completion_precopy(MigrationState *s, qemu_mutex_lock_iothread(); migration_downtime_start(s); - qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER, NULL); s->vm_old_state = runstate_get(); global_state_store(); @@ -3136,7 +3134,7 @@ static void migration_iteration_finish(MigrationState *s) case MIGRATION_STATUS_FAILED: case MIGRATION_STATUS_CANCELLED: case MIGRATION_STATUS_CANCELLING: - if (s->vm_old_state == RUN_STATE_RUNNING) { + if (runstate_is_live(s->vm_old_state)) { if (!runstate_check(RUN_STATE_SHUTDOWN)) { vm_start(); }