Re: [PATCH 0/2] migration: include timing and RAM stats on destination when query-migrate

[Fabiano Rosas <farosas@suse.de>]

Trieu Huynh <vikingtc4@gmail.com> writes:

> From: Trieu Huynh <vikingtc4@gmail.com>
>
> When query-migrate is called on the *destination* QEMU after a precopy
> migration completes it returns only {"status": "completed"} — no timing,
> no RAM statistics.  The source correctly returns total-time, downtime,
> setup-time, and full ram stats.
>
> This series fixes the gap in two commits:
>
> * commit 1: Track start/end timestamps and per-page-type counters in
>   MigrationIncomingState, recorded in the receive path.
>
> * commit 2: Make source-only MigrationStats fields optional in the QAPI
>   schema so the destination can populate info->ram with only the fields
>   that are meaningful on the receive side.  Fields computed from tracked
>   counters (transferred, normal, duplicate, mbps, pages-per-second) are
>   shown; source-only fields (dirty-sync-count, precopy-bytes, etc.) are
>   absent.
>
> The QAPI change (commit 2) is ABI-compatible: optional fields that are
> not set are simply absent from the output.  Source-side callers are
> unaffected because populate_ram_info() sets all optional fields via
> has_* setters, so the source output is identical to before.
>
> On dst, {"execute":"query-migrate"}
> * As-is:
> {
>     "return": {
>         "status": "completed"
> }
> * To-be:
> {
>     "return": {
>         "status": "completed",
>         "total-time": 94,
>         "ram": {
>             "total": 554508288,
>             "pages-per-second": 1440234,
>             "page-size": 4096,
>             "remaining": 0,
>             "mbps": 97.955404255319152,
>             "transferred": 1150976,
>             "duplicate": 135101,
>             "normal-bytes": 1150976,
>             "normal": 281
>         }
>     }
> }
>
> Resolves: https://gitlab.com/qemu-project/qemu/-/issues/3151
>
> Trieu Huynh (2):
>   migration: track timing and received pages in MigrationIncomingState
>   migration: expose RAM stats and timing on destination via
>     query-migrate
>
>  migration/migration.c | 37 +++++++++++++++++++++++++++++++++++++
>  migration/migration.h | 17 +++++++++++++++++
>  migration/ram.c       |  3 +++
>  qapi/migration.json   | 14 +++++++-------
>  4 files changed, 64 insertions(+), 7 deletions(-)

Hi, remember to copy the interested people in your series. Using
get_maintainers is correct, but when there's already a discussion about
the topic it's good to add some CCs manually.

+CC Daniel and Claudio