Re: [PATCH v2 15/24] migration: Provide helper for save vm description

[Fabiano Rosas <farosas@suse.de>]

Peter Xu <peterx@redhat.com> writes:

> Provide two smaller helpers to dump the vm desc.  Preparing to move it out
> and generalize device state dump.
>
> Signed-off-by: Peter Xu <peterx@redhat.com>
> ---
>  migration/savevm.h |  1 +
>  migration/savevm.c | 35 +++++++++++++++++++++++------------
>  2 files changed, 24 insertions(+), 12 deletions(-)
>
> diff --git a/migration/savevm.h b/migration/savevm.h
> index d0596d1d62..f957f851ef 100644
> --- a/migration/savevm.h
> +++ b/migration/savevm.h
> @@ -50,6 +50,7 @@ void qemu_savevm_state_pending_estimate(uint64_t *must_precopy,
>  int qemu_savevm_state_complete_precopy_iterable(QEMUFile *f, bool in_postcopy);
>  bool qemu_savevm_state_postcopy_prepare(QEMUFile *f, Error **errp);
>  void qemu_savevm_state_end(QEMUFile *f);
> +void qemu_savevm_state_end_precopy(MigrationState *s, QEMUFile *f);
>  void qemu_savevm_send_ping(QEMUFile *f, uint32_t value);
>  void qemu_savevm_send_open_return_path(QEMUFile *f);
>  int qemu_savevm_send_packaged(QEMUFile *f, const uint8_t *buf, size_t len);
> diff --git a/migration/savevm.c b/migration/savevm.c
> index a787691352..41560b97a4 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -1669,13 +1669,34 @@ ret_fail_abort_threads:
>      return -1;
>  }
>  
> +static void qemu_savevm_state_vm_desc(MigrationState *s, QEMUFile *f)
> +{
> +    JSONWriter *vmdesc = s->vmdesc;
> +    int vmdesc_len;
> +
> +    if (vmdesc) {
> +        json_writer_end_array(vmdesc);
> +        json_writer_end_object(vmdesc);
> +        vmdesc_len = strlen(json_writer_get(vmdesc));
> +
> +        qemu_put_byte(f, QEMU_VM_VMDESCRIPTION);
> +        qemu_put_be32(f, vmdesc_len);
> +        qemu_put_buffer(f, (uint8_t *)json_writer_get(vmdesc), vmdesc_len);
> +    }
> +}
> +
> +void qemu_savevm_state_end_precopy(MigrationState *s, QEMUFile *f)
> +{
> +    qemu_savevm_state_end(f);
> +    qemu_savevm_state_vm_desc(s, f);
> +}
> +
>  int qemu_savevm_state_complete_precopy_non_iterable(QEMUFile *f,
>                                                      bool in_postcopy)
>  {
>      MigrationState *ms = migrate_get_current();
>      int64_t start_ts_each, end_ts_each;
>      JSONWriter *vmdesc = ms->vmdesc;
> -    int vmdesc_len;
>      SaveStateEntry *se;
>      Error *local_err = NULL;
>      int ret;
> @@ -1705,17 +1726,7 @@ int qemu_savevm_state_complete_precopy_non_iterable(QEMUFile *f,
>  
>      if (!in_postcopy) {
>          /* Postcopy stream will still be going */
> -        qemu_savevm_state_end(f);
> -
> -        if (vmdesc) {
> -            json_writer_end_array(vmdesc);
> -            json_writer_end_object(vmdesc);
> -            vmdesc_len = strlen(json_writer_get(vmdesc));
> -
> -            qemu_put_byte(f, QEMU_VM_VMDESCRIPTION);
> -            qemu_put_be32(f, vmdesc_len);
> -            qemu_put_buffer(f, (uint8_t *)json_writer_get(vmdesc), vmdesc_len);
> -        }
> +        qemu_savevm_state_end_precopy(ms, f);
>      }
>  
>      trace_vmstate_downtime_checkpoint("src-non-iterable-saved");

Reviewed-by: Fabiano Rosas <farosas@suse.de>