* Peter Xu (pet...@redhat.com) wrote:
> migrate_incoming command is previously only used when we were providing
> "-incoming defer" in the command line, to defer the incoming migration
> channel creation.
>
> However there is similar requirement when we are paused during postcopy
> migration. The old incoming channel might have been destroyed already.
> We may need another new channel for the recovery to happen.
>
> This patch leveraged the same interface, but allows the user to specify
> incoming migration channel even for paused postcopy.
>
> Meanwhile, now migration listening ports are always detached manually
> using the tag, rather than using return values of dispatchers.
>
> Signed-off-by: Peter Xu <pet...@redhat.com>
I think this patch is OK now, except for that top level question I've asked
against 00 about how the new incoming ever gets to start up.
Reviewed-by: Dr. David Alan Gilbert <dgilb...@redhat.com>
> ---
> migration/exec.c | 2 +-
> migration/fd.c | 2 +-
> migration/migration.c | 58
> +++++++++++++++++++++++++++++++++++++++++++-------
> migration/socket.c | 4 +---
> migration/trace-events | 2 ++
> 5 files changed, 55 insertions(+), 13 deletions(-)
>
> diff --git a/migration/exec.c b/migration/exec.c
> index a0796c2c70..9d20d10899 100644
> --- a/migration/exec.c
> +++ b/migration/exec.c
> @@ -49,7 +49,7 @@ static gboolean exec_accept_incoming_migration(QIOChannel
> *ioc,
> {
> migration_channel_process_incoming(ioc);
> object_unref(OBJECT(ioc));
> - return G_SOURCE_REMOVE;
> + return G_SOURCE_CONTINUE;
> }
>
> /*
> diff --git a/migration/fd.c b/migration/fd.c
> index 7ead2f26cc..54b36888e2 100644
> --- a/migration/fd.c
> +++ b/migration/fd.c
> @@ -49,7 +49,7 @@ static gboolean fd_accept_incoming_migration(QIOChannel
> *ioc,
> {
> migration_channel_process_incoming(ioc);
> object_unref(OBJECT(ioc));
> - return G_SOURCE_REMOVE;
> + return G_SOURCE_CONTINUE;
> }
>
> /*
> diff --git a/migration/migration.c b/migration/migration.c
> index a4cdedcde8..9b7fc56ed8 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -179,6 +179,17 @@ void migration_incoming_state_destroy(void)
> qemu_event_reset(&mis->main_thread_load_event);
> }
>
> +static bool migrate_incoming_detach_listen(MigrationIncomingState *mis)
> +{
> + if (mis->listen_task_tag) {
> + /* Never fail */
> + g_source_remove(mis->listen_task_tag);
> + mis->listen_task_tag = 0;
> + return true;
> + }
> + return false;
> +}
> +
> static void migrate_generate_event(int new_state)
> {
> if (migrate_use_events()) {
> @@ -463,10 +474,9 @@ void migration_fd_process_incoming(QEMUFile *f)
>
> /*
> * When reach here, we should not need the listening port any
> - * more. We'll detach the listening task soon, let's reset the
> - * listen task tag.
> + * more. Detach the listening port explicitly.
> */
> - mis->listen_task_tag = 0;
> + migrate_incoming_detach_listen(mis);
> }
>
> void migration_ioc_process_incoming(QIOChannel *ioc)
> @@ -1422,14 +1432,46 @@ void qmp_migrate_incoming(const char *uri, Error
> **errp)
> {
> Error *local_err = NULL;
> static bool once = true;
> + MigrationIncomingState *mis = migration_incoming_get_current();
> +
>
> - if (!deferred_incoming) {
> - error_setg(errp, "For use with '-incoming defer'");
> + if (mis->state == MIGRATION_STATUS_POSTCOPY_PAUSED) {
> + if (mis->listen_task_tag) {
> + error_setg(errp, "We already have a listening port!");
> + return;
> + } else {
> + /*
> + * We are in postcopy-paused state, and we don't have
> + * listening port. It's very possible that the old
> + * listening port is already gone, so we allow to create a
> + * new one.
> + *
> + * NOTE: RDMA migration currently does not really use
> + * listen_task_tag for now, so even if listen_task_tag is
> + * zero, RDMA can still have its accept port listening.
> + * However, RDMA is not supported by postcopy at all (yet), so
> + * we are safe here.
> + */
> + trace_migrate_incoming_recover();
> + }
> + } else if (deferred_incoming) {
> + /*
> + * We don't need recovery, but we possibly has a deferred
> + * incoming parameter, this allows us to manually specify
> + * incoming port once.
> + */
> + if (!once) {
> + error_setg(errp, "The incoming migration has already been
> started");
> + return;
> + } else {
> + /* PASS */
> + trace_migrate_incoming_deferred();
> + }
> + } else {
> + error_setg(errp, "Migrate-incoming is only allowed for either "
> + "deferred incoming, or postcopy paused stage.");
> return;
> }
> - if (!once) {
> - error_setg(errp, "The incoming migration has already been started");
> - }
>
> qemu_start_incoming_migration(uri, &local_err);
>
> diff --git a/migration/socket.c b/migration/socket.c
> index e8f3325155..54095a80a0 100644
> --- a/migration/socket.c
> +++ b/migration/socket.c
> @@ -155,10 +155,8 @@ out:
> if (migration_has_all_channels()) {
> /* Close listening socket as its no longer needed */
> qio_channel_close(ioc, NULL);
> - return G_SOURCE_REMOVE;
> - } else {
> - return G_SOURCE_CONTINUE;
> }
> + return G_SOURCE_CONTINUE;
> }
>
>
> diff --git a/migration/trace-events b/migration/trace-events
> index 98c2e4de58..65b1c7e459 100644
> --- a/migration/trace-events
> +++ b/migration/trace-events
> @@ -136,6 +136,8 @@ process_incoming_migration_co_end(int ret, int ps)
> "ret=%d postcopy-state=%d"
> process_incoming_migration_co_postcopy_end_main(void) ""
> migration_set_incoming_channel(void *ioc, const char *ioctype) "ioc=%p
> ioctype=%s"
> migration_set_outgoing_channel(void *ioc, const char *ioctype, const char
> *hostname) "ioc=%p ioctype=%s hostname=%s"
> +migrate_incoming_deferred(void) ""
> +migrate_incoming_recover(void) ""
>
> # migration/rdma.c
> qemu_rdma_accept_incoming_migration(void) ""
> --
> 2.13.6
>
--
Dr. David Alan Gilbert / dgilb...@redhat.com / Manchester, UK
