Re: [PATCH v2 4/4] vhost-user: add skip_drain param to GET_VRING_BASE

[Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>]

On 11.03.26 11:47, Alexandr Moshkov wrote:
> In case of migration of QEMU from the new version (where the
> inllight-migration parameter is present), to the old one (where it is
> absent) there is no way to disable this feature on the backend during
> runtime.
> 
> This commit slightly changes the semantics of the protocol feature
> VHOST_USER_PROTOCOL_F_GET_VRING_BASE_INFLIGHT. Enabling this feature
> adds a new parameter for GET_VRING_BASE, which allows to control the
> drain in-flight requests on the backend.
> Thus, QEMU will be able to turn this feature on GET_VRING_BASE off and
> on anytime.
> 
> In vhost-user-blk use inflight_migration param to enable skip_drain to
> suspend in-flight I/O requests, and then migrate them throught inflight
> subsection.
> 
> Also now QEMU will always try to setup
> VHOST_USER_PROTOCOL_F_GET_VRING_BASE_INFLIGHT protocol featrue with
> backend. This will allow to use skip_drain parameter on GET_VRING_BASE
> message.
> 
> Signed-off-by: Alexandr Moshkov<dtalexundeer@yandex-team.ru>

Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>


Is it too late for 11.0, to fix protocol disadvantage we've added?

Or could it be fixed in 11.1?


-- 
Best regards,
Vladimir