On 10/20/25 14:55, Markus Armbruster wrote:
Alexandr Moshkov<[email protected]> writes:
Hi!
During inter-host migration, waiting for disk requests to be drained
in the vhost-user backend can incur significant downtime.
This can be avoided if QEMU migrates the inflight region in vhost-user-blk.
Thus, during the qemu migration, the vhost-user backend can cancel all inflight
requests and
then, after migration, they will be executed on another host.
At first, I tried to implement migration for all vhost-user devices that
support inflight at once,
but this would require a lot of changes both in vhost-user-blk (to transfer it
to the base class) and
in the vhost-user-base base class (inflight implementation and remodeling + a
large refactor).
Therefore, for now I decided to leave this idea for later and
implement the migration of the inflight region first for vhost-user-blk.
How is this work related to Vladimir's "vhost-user-blk: live-backend
local migration"?
Hi!
Vladimir's work is only related to local migration (including inflight
region fd), when my patch allows to migrate inflight requests to another
host to reduce downtime without waiting for disk requests to be drained.
