Re: [PATCH v3 24/24] vfio/migration: Multifd device state transfer support - send side

["Cédric Le Goater" <clg@redhat.com>]

>>> By the way, this kind of an implicit dependency in VMState between devices
>>> is really hard to manage, there should be a way to specify it in code somehow..
>>
>> vmstate has a MigrationPriority field to order loading between
>> devices. Maybe we could extend but I think it is better to handle
>> ordering at the device level when there are no external dependencies.
>> It should be well documented though in the code.
>>
> 
> To be clear, by "handling ordering at the device level" you mean
> just disabling this functionality for ARM64 as proposed above?

I meant handling the migration ordering in the device load/save
handlers without making assumptions on other devices.

Regarding ARM64, it would be unfortunate to deactivate the feature
since migration works correctly today, on AMR64 64k kernels too,
and this series should improve also downtime. Support can be added
gradually though.


Thanks,

C.