* Peter Xu (pet...@redhat.com) wrote:
> This patch detects the "resume" flag of migration command, rebuild the
> channels only if the flag is set.
>
> Signed-off-by: Peter Xu <pet...@redhat.com>
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> ---
> migration/migration.c | 92
> ++++++++++++++++++++++++++++++++++++++-------------
> 1 file changed, 69 insertions(+), 23 deletions(-)
>
> diff --git a/migration/migration.c b/migration/migration.c
> index 15b8eb1..deb947b 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -1233,49 +1233,75 @@ bool migration_is_blocked(Error **errp)
> return false;
> }
>
> -void qmp_migrate(const char *uri, bool has_blk, bool blk,
> - bool has_inc, bool inc, bool has_detach, bool detach,
> - bool has_resume, bool resume, Error **errp)
> +/* Returns true if continue to migrate, or false if error detected */
> +static bool migrate_prepare(MigrationState *s, bool blk, bool blk_inc,
> + bool resume, Error **errp)
> {
> Error *local_err = NULL;
> - MigrationState *s = migrate_get_current();
> - const char *p;
> +
> + if (resume) {
> + if (s->state != MIGRATION_STATUS_POSTCOPY_PAUSED) {
> + error_setg(errp, "Cannot resume if there is no "
> + "paused migration");
> + return false;
> + }
> + /* This is a resume, skip init status */
> + return true;
> + }
>
> if (migration_is_setup_or_active(s->state) ||
> s->state == MIGRATION_STATUS_CANCELLING ||
> s->state == MIGRATION_STATUS_COLO) {
> error_setg(errp, QERR_MIGRATION_ACTIVE);
> - return;
> + return false;
> }
> +
> if (runstate_check(RUN_STATE_INMIGRATE)) {
> error_setg(errp, "Guest is waiting for an incoming migration");
> - return;
> + return false;
> }
>
> if (migration_is_blocked(errp)) {
> - return;
> + return false;
> }
>
> - if ((has_blk && blk) || (has_inc && inc)) {
> + if (blk || blk_inc) {
> if (migrate_use_block() || migrate_use_block_incremental()) {
> error_setg(errp, "Command options are incompatible with "
> "current migration capabilities");
> - return;
> + return false;
> }
> migrate_set_block_enabled(true, &local_err);
> if (local_err) {
> error_propagate(errp, local_err);
> - return;
> + return false;
> }
> s->must_remove_block_options = true;
> }
>
> - if (has_inc && inc) {
> + if (blk_inc) {
> migrate_set_block_incremental(s, true);
> }
>
> migrate_init(s);
>
> + return true;
> +}
> +
> +void qmp_migrate(const char *uri, bool has_blk, bool blk,
> + bool has_inc, bool inc, bool has_detach, bool detach,
> + bool has_resume, bool resume, Error **errp)
> +{
> + Error *local_err = NULL;
> + MigrationState *s = migrate_get_current();
> + const char *p;
> +
> + if (!migrate_prepare(s, has_blk && blk, has_inc && inc,
> + has_resume && resume, errp)) {
> + /* Error detected, put into errp */
> + return;
> + }
> +
> if (strstart(uri, "tcp:", &p)) {
> tcp_start_outgoing_migration(s, p, &local_err);
> #ifdef CONFIG_RDMA
> @@ -1697,7 +1723,8 @@ out:
> return NULL;
> }
>
> -static int open_return_path_on_source(MigrationState *ms)
> +static int open_return_path_on_source(MigrationState *ms,
> + bool create_thread)
> {
>
> ms->rp_state.from_dst_file = qemu_file_get_return_path(ms->to_dst_file);
> @@ -1706,6 +1733,12 @@ static int open_return_path_on_source(MigrationState
> *ms)
> }
>
> trace_open_return_path_on_source();
> +
> + if (!create_thread) {
> + /* We're done */
> + return 0;
> + }
> +
> qemu_thread_create(&ms->rp_state.rp_thread, "return path",
> source_return_path_thread, ms, QEMU_THREAD_JOINABLE);
>
> @@ -2263,15 +2296,24 @@ static void *migration_thread(void *opaque)
>
> void migrate_fd_connect(MigrationState *s)
> {
> - s->expected_downtime = s->parameters.downtime_limit;
> - s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s);
> + int64_t rate_limit;
> + bool resume = s->state == MIGRATION_STATUS_POSTCOPY_PAUSED;
>
> - qemu_file_set_blocking(s->to_dst_file, true);
> - qemu_file_set_rate_limit(s->to_dst_file,
> - s->parameters.max_bandwidth / XFER_LIMIT_RATIO);
> + if (resume) {
> + /* This is a resumed migration */
> + rate_limit = INT64_MAX;
> + } else {
> + /* This is a fresh new migration */
> + rate_limit = s->parameters.max_bandwidth / XFER_LIMIT_RATIO;
> + s->expected_downtime = s->parameters.downtime_limit;
> + s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s);
>
> - /* Notify before starting migration thread */
> - notifier_list_notify(&migration_state_notifiers, s);
> + /* Notify before starting migration thread */
> + notifier_list_notify(&migration_state_notifiers, s);
> + }
> +
> + qemu_file_set_rate_limit(s->to_dst_file, rate_limit);
> + qemu_file_set_blocking(s->to_dst_file, true);
>
> /*
> * Open the return path. For postcopy, it is used exclusively. For
> @@ -2279,15 +2321,19 @@ void migrate_fd_connect(MigrationState *s)
> * QEMU uses the return path.
> */
> if (migrate_postcopy_ram() || migrate_use_return_path()) {
> - if (open_return_path_on_source(s)) {
> + if (open_return_path_on_source(s, !resume)) {
> error_report("Unable to open return-path for postcopy");
> - migrate_set_state(&s->state, MIGRATION_STATUS_SETUP,
> - MIGRATION_STATUS_FAILED);
> + migrate_set_state(&s->state, s->state, MIGRATION_STATUS_FAILED);
> migrate_fd_cleanup(s);
> return;
> }
> }
>
> + if (resume) {
> + /* TODO: do the resume logic */
> + return;
> + }
> +
> qemu_thread_create(&s->thread, "live_migration", migration_thread, s,
> QEMU_THREAD_JOINABLE);
> s->migration_thread_running = true;
> --
> 2.7.4
>
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
