Commit 7287cbd4 authored by Peter Xu's avatar Peter Xu Committed by Juan Quintela
Browse files

migration: move vm_old_running into global state 



Firstly, it was passed around.  Let's just move it into MigrationState
just like many other variables as state of migration, renaming it to
vm_was_running.

One thing to mention is that for postcopy, we actually don't need this
knowledge at all since postcopy can't resume a VM even if it fails (we
can see that from the old code too: when we try to resume we also check
against "entered_postcopy" variable).  So further we do this:

- in postcopy_start(), we don't update vm_old_running since useless
- in migration_thread(), we don't need to check entered_postcopy when
  resume, since it's only used for precopy.

Comment this out too for that variable definition.

Reviewed-by: default avatarJuan Quintela <quintela@redhat.com>
Signed-off-by: default avatarPeter Xu <peterx@redhat.com>
Signed-off-by: default avatarJuan Quintela <quintela@redhat.com>
parent 4af246a3

migration/migration.c

+7 −10
Original line number Diff line number Diff line
@@ -1302,6 +1302,7 @@ MigrationState *migrate_init(void) 


    s->start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);

    s->total_time = 0;

    s->vm_was_running = false;

    return s;

}
@@ -1885,7 +1886,7 @@ static int await_return_path_close_on_source(MigrationState *ms) 
 * Switch from normal iteration to postcopy

 * Returns non-0 on error

 */

static int postcopy_start(MigrationState *ms, bool *old_vm_running)

static int postcopy_start(MigrationState *ms)

{

    int ret;

    QIOChannelBuffer *bioc;
@@ -1903,7 +1904,6 @@ static int postcopy_start(MigrationState *ms, bool *old_vm_running) 
    trace_postcopy_start_set_run();



    qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);

    *old_vm_running = runstate_is_running();

    global_state_store();

    ret = vm_stop_force_state(RUN_STATE_FINISH_MIGRATE);

    if (ret < 0) {
@@ -2094,11 +2094,9 @@ static int migration_maybe_pause(MigrationState *s, 
 *

 * @s: Current migration state

 * @current_active_state: The migration state we expect to be in

 * @*old_vm_running: Pointer to old_vm_running flag

 * @*start_time: Pointer to time to update

 */

static void migration_completion(MigrationState *s, int current_active_state,

                                 bool *old_vm_running,

                                 int64_t *start_time)

{

    int ret;
@@ -2107,7 +2105,7 @@ static void migration_completion(MigrationState *s, int current_active_state, 
        qemu_mutex_lock_iothread();

        *start_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);

        qemu_system_wakeup_request(QEMU_WAKEUP_REASON_OTHER);

        *old_vm_running = runstate_is_running();

        s->vm_was_running = runstate_is_running();

        ret = global_state_store();



        if (!ret) {
@@ -2213,7 +2211,6 @@ static void *migration_thread(void *opaque) 
    int64_t threshold_size = 0;

    int64_t start_time = initial_time;

    int64_t end_time;

    bool old_vm_running = false;

    bool entered_postcopy = false;

    /* The active state we expect to be in; ACTIVE or POSTCOPY_ACTIVE */

    enum MigrationStatus current_active_state = MIGRATION_STATUS_ACTIVE;
@@ -2272,7 +2269,7 @@ static void *migration_thread(void *opaque) 
                    pend_nonpost <= threshold_size &&

                    atomic_read(&s->start_postcopy)) {



                    if (!postcopy_start(s, &old_vm_running)) {

                    if (!postcopy_start(s)) {

                        current_active_state = MIGRATION_STATUS_POSTCOPY_ACTIVE;

                        entered_postcopy = true;

                    }
@@ -2284,7 +2281,7 @@ static void *migration_thread(void *opaque) 
            } else {

                trace_migration_thread_low_pending(pending_size);

                migration_completion(s, current_active_state,

                                     &old_vm_running, &start_time);

                                     &start_time);

                break;

            }

        }
@@ -2357,9 +2354,9 @@ static void *migration_thread(void *opaque) 
            * Fixme: we will run VM in COLO no matter its old running state.

            * After exited COLO, we will keep running.

            */

            old_vm_running = true;

            s->vm_was_running = true;

        }

        if (old_vm_running && !entered_postcopy) {

        if (s->vm_was_running) {

            vm_start();

        } else {

            if (runstate_check(RUN_STATE_FINISH_MIGRATE)) {

migration/migration.h

+6 −0
Original line number Diff line number Diff line
@@ -123,6 +123,12 @@ struct MigrationState 
    int64_t expected_downtime;

    bool enabled_capabilities[MIGRATION_CAPABILITY__MAX];

    int64_t setup_time;

    /*

     * Whether guest was running when we enter the completion stage.

     * If migration is interrupted by any reason, we need to continue

     * running the guest on source.

     */

    bool vm_was_running;



    /* Flag set once the migration has been asked to enter postcopy */

    bool start_postcopy;