Re: [Qemu-devel] [PATCH] hmp/info_migration: formatting migration capability output

[Markus Armbruster <armbru@redhat.com>]

Subject doesn't quite conform to conventions.  Suggest

    hmp: Improve how "info migrate" formats capabilities

Wei Yang <richardw.yang@linux.intel.com> writes:

> Current we put all migration capability in one line, which make it hard
> to read them and someone them are missed due to terminal width.
>
> This patch formats it to print 4 in one line, which looks like this now:
>
> capabilities:
>               xbzrle: off         rdma-pin-all: off        auto-converge: off          zero-blocks: off
>             compress:  on               events: off         postcopy-ram: off               x-colo: off
>          release-ram: off                block: off          return-path: off pause-before-switchover: off
>              multifd: off        dirty-bitmaps: off   postcopy-blocktime: off  late-block-activate: off
>      x-ignore-shared: off
>
> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com>
> ---
>  monitor/hmp-cmds.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/monitor/hmp-cmds.c b/monitor/hmp-cmds.c
> index 5ca3ebe942..29ce5b73e4 100644
> --- a/monitor/hmp-cmds.c
> +++ b/monitor/hmp-cmds.c
> @@ -229,9 +229,13 @@ void hmp_info_migrate(Monitor *mon, const QDict *qdict)
>  
>      /* do not display parameters during setup */
>      if (info->has_status && caps) {
> +        int index = 0;
>          monitor_printf(mon, "capabilities: ");
> -        for (cap = caps; cap; cap = cap->next) {
> -            monitor_printf(mon, "%s: %s ",
> +        for (cap = caps; cap; cap = cap->next, index++) {
> +            if (!(index % 4)) {
> +                monitor_printf(mon, "\n");
> +            }
> +            monitor_printf(mon, "%20s: %3s ",
>                             MigrationCapability_str(cap->value->capability),
>                             cap->value->state ? "on" : "off");
>          }

This assumes migration capability names are at most 20 characters long.
late-block-activate is pushing it already: 19 characters.

It adds up to 104 characters per line, which is rather wide.

What about putting each capability on its own line, just like globals,
and just like "info migrate_capabilities"?

(qemu) info migrate
globals:
store-global-state: on
only-migratable: off
send-configuration: on
send-section-footer: on
decompress-error-check: on
clear-bitmap-shift: 18
capabilities:
xbzrle: off
rdma-pin-all: off
auto-converge: off
[...]